Combined effects of biosolids application and irrigation with reclaimed wastewater on transport of pharmaceutical compounds in arable soils

Metformin and lamotrigine sorption on a digestate amended soil in presence of trace metal contamination

The antidiabetic drug metformin and antiepileptic drug lamotrigine are contaminants of emerging concern that have been detected in biowaste-derived amendments and in the environment, and their fate must be carefully studied. This work aimed to evaluate their sorption behaviour on soil upon digestate application. Experiments were conducted on soil and digestate-amended soil as a function of time to study kinetic processes, and at equilibrium also regarding the influence of trace metals (Pb, Ni, Cr, Co, Cu, Zn) at ratio pharmaceutical/metal 1/1, 1/10, and 1/100. Pharmaceutical desorption experiments were also conducted to assess their potential mobility to groundwater. Results revealed that digestate amendment increased metformin and lamotrigine adsorbed amounts by 210% and 240%, respectively, increasing organic matter content. Metformin adsorption kinetics were best described by Langmuir model and those of lamotrigine by Elovich and intraparticle diffusion models. Trace metals did not significantly affect the adsorption of metformin in amended soil while significantly decreased that of lamotrigine by 12-39%, with exception for Cu2+ that increased both pharmaceuticals adsorbed amounts by 5 - 8%. This study highlighted the influence of digestate amendment on pharmaceutical adsorption and fate in soil, which must be considered in the circular economy scenario of waste-to-resource.

Factors influencing the fate of chemical food safety hazards in the terrestrial circular primary food production system-A comprehensive review

Food safety is recognized as a major hurdle in the transition toward circular food production systems due to the potential reintroduction and accumulation of chemical contaminants in these food systems. Effectively managing these hazardous contaminants in a risk-based manner requires quantitative insights into the factors influencing the presence and fate of contaminants in the entire circular food chain. A systematic literature review was performed to gain an up-to-date overview of the known factors and their influence on the transfer and accumulation of contaminants. This review focused on the terrestrial circular primary food production system, including the pathways between waste- or byproduct-based fertilizers, soil, crops, animal feed, and farmed animals. This review revealed an imbalance in research regarding the different pathways: studies on the soil-to-crop pathway were most abundant. The factors identified can be categorized as compound-related (intrinsic) factors, such as hydrophobicity, molecular weight, and chain length, and extrinsic factors, such as soil organic matter and carbon, pH, milk yield of cows, crop age, and biomass. Quantitative data on the influence of the identified factors were limited. Most studies quantified the influence of individual factors, whereas only a few studies quantified the combined effect of multiple factors. By providing a holistic insight into the influential factors and the quantification of their influence on the fate of contaminants, this review contributes to the improvement of food safety management for chemical hazards when transitioning to a circular food system.

Mobility of antipyretic drugs with different molecular structures in saturated soil porous media

In the post-COVID-19 era, extensive quantities of antipyretic drugs are being haphazardly released from households into the environment, which may pose potential risks to ecological systems and human health. Identification of the mobility behaviors of these compounds in the subsurface environment is crucial to understand the environmental fate of these common contaminants. The mobility properties of three broad-spectrum antipyretic drugs, including ibuprofen (IBF), indometacin (IMC), and acetaminophen (APAP), in porous soil media, were investigated in this study. The results showed that the mobility of the three drugs (the background electrolyte was Na+) through the soil column followed the order of APAP > IBF > IMC. The difference in the physicochemical characteristics of various antipyretic drugs (e.g., the molecular structure and hydrophobicity) could explain this trend. Unlike Na+, Ca2+ ions tended to serve as bridging agents by linking the soil grains and antipyretic molecules, leading to the relatively weak mobility behaviors of antipyretic drugs. Furthermore, for a given antipyretic drug, the antipyretic mobility was promoted when the background solution pH values were raised from 5.0 to 9.0. The phenomenon stemmed from the improved electrostatic repulsion between the dissociated species of antipyretic molecules and soil grains, as well as the weakened hydrophobic interactions between antipyretic drugs and soil organic matter. Furthermore, a two-site non-equilibrium transport model was used to estimate the mobility of antipyretic drugs. The results obtained from this work provide vital information illustrating the transport and retention of various antipyretic drugs in aquifers.

Influence of Manure as a Complex Mixture on Soil Sorption of Pharmaceuticals-Studies with Selected Chemical Components of Manure

Pharmaceutically active compounds (PhACs) enter soil with organic waste materials such as manure. Such complex substrates differently affect PhACs' soil sorption. For the first time, batch experiments were conducted using five selected chemicals as model constituents to elucidate the effects. Urea, phosphate (KH₂PO₄), acetic acid, phenol and nonadecanoic acid (C:19) altered the sorption strength and/or nonlinearity of sulfadiazine, caffeine, and atenolol in an arable Cambisol topsoil. The nonlinear Freundlich model best described sorption. Overall, the PhACs' Freundlich coefficients (sorption strength) increased in the sequence urea < phosphate < phenol < C:19 < acetic acid, while the Freundlich exponents largely decreased, indicating increasing sorption specificity. The effects on sulfadiazine and caffeine were rather similar, but in many cases different from atenolol. Phosphate mobilized sulfadiazine and caffeine and urea mobilized sulfadiazine, which was explained by sorption competition resulting from specific preference of similar sorption sites. Soil sorbed phenol strongly increased the sorption of all three PhACs; phenolic functional groups are preferred sorption sites of PhACs in soil. The large increase in sorption of all PhACs by acetic acid was attributed to a loosening of the soil organic matter and thus the creation of additional sorption sites. The effect of C:19 fatty acid, however, was inconsistent. These results help to better understand the sorption of PhACs in soil-manure mixtures.

Effect of biosolids amendment on the fate and mobility of non-steroidal anti-inflammatory drugs (NSAIDs) in a field-based lysimeter cell study

Non-steroidal anti-inflammatory drugs (NSAIDs) are widely used globally to treat and prevent illness. Biosolids change physico-chemical characteristics of soil and can affect the mobility of NSAIDs. A field-based lysimeter study evaluated the effect of three rates (0, 7, and 28 Mg ha^-1) of alkaline treated biosolids (ATB) on the leaching potential of naproxen (NPX), ibuprofen (IBF), and ketoprofen (KTF) over 34 days in a sandy loam textured soil. Although all three NSAIDs in the lysimeter cells vertically migrated to deeper soil depths after spiking, the sum of all NPX, IBF, and KTF detected in the leachate samples from all treatments were only 0.03%, 0.02%, and 0.04% of the initial spiking mass to the surface soil, respectively. A mass balance analysis indicated a low accumulation of these compounds in the soil at the end of the study (Day 34) from all treatments with only 4.8%, 0.5%, and 0.7% of initial spiked NPX, IBF, and KTF, respectively. Application of ATB significantly increased soil pH and organic matter (OM) content of the soils but did not impact retention of the compounds in the soil profile. Overall, all three NSAIDs in the present study presented low mobility in the loamy sand textured agricultural soil.

Advancements in the dominion of fate and transport of pharmaceuticals and personal care products in the environment-a bibliometric study

The study on the fate and transport of Pharmaceuticals and Personal Care Products, PPCPs (FTP) in the environment, has received particular attention for over two decades. The PPCPs threaten ecology and human health even at low concentrations due to their synergistic effects and long-range transport. The research aims to provide an inclusive map of the scientific background of FTP research over the last 25 years, from 1996 to 2020, to identify the main characteristics, evolution, salient research themes, trends, and research hotspots in the field of interest. Bibliometric networks were synthesized and analyzed for 577 journal articles extracted from the Scopus database. Consequently, seven major themes of FTP research were identified as follows: (i) PPCPs category; (ii) hazardous effects; (iii) occurrence of PPCPs; (iv) PPCPs in organisms; (v) remediation; (vi) FTP-governing processes; and (vii) assessment in the environment. The themes gave an in-depth picture of the sources of PPCPs and their transport and fate processes in the environment, which originated from sewage treatment plants and transported further to sediment/soils/groundwater/oceans that act as the PPCPs' major sink. The article provided a rigorous analysis of the research landscape in the FTP study conducted during the specified years. The prominent research themes, content analysis, and research hotspots identified in the study may serve as the basis of real-time guidance to lead future research areas and a prior review for policymakers and practitioners.

Fate of contaminants of emerging concern in the reclaimed wastewater-soil-plant continuum

Reclaimed wastewater irrigation, a common agricultural practice in water-scarce regions, chronically exposes the agricultural environment to a wide range of contaminants of emerging concern (CECs) including pharmaceuticals and personal care products. Here we provide new data and insights into the processes governing the translocation of CECs in the irrigation water-soil-plant continuum based on a comprehensive dataset from 445 commercial fields irrigated with reclaimed wastewater. We report on CEC exposures in irrigation water, soils, and edible produce (leafy greens, carrots, potatoes, bananas, tomatoes, avocados, and citrus fruits). Our data show that CEC concentrations in irrigation water and their physiochemical properties (mainly charge and lipophilicity) are the main factors governing their translocation and accumulation in the soil-plant continuum. CECs exhibiting the highest detection frequency in plants (lamotrigine, venlafaxine, and carbamazepine) showed a reduction in their leaf accumulation factor with increasing soil organic matter content. The higher soil organic matter likely reduced the available CEC concentration in the soil solution due to soil-CEC interactions, leading to reduced uptake. Interestingly, the concentration of carbamazepine in the leaves showed a saturation-like trend when plotted against its concentration in the soils. This probably resulted from steady-state conditions when uptake equals in-planta decomposition. Our data indicate that due to continuous reclaimed wastewater irrigation, the soil acts as a sink for CECs. CECs in the soil reservoir can be desorbed into the soil solution during the rainy season and be taken up by rain-fed crops.

Pharmaceuticals as Emerging Pollutants in the Reclaimed Wastewater Used in Irrigation and Their Effects on Plants, Soils, and Groundwater

Pharmaceuticals and personal care products (PPCPs) were investigated in five wastewater treatment plants (WWTPs), groundwater, irrigated soils, and plants in Amman and Al-Balqa governorates in Jordan. PPCPs were extracted from water samples by solid-phase extraction (SPE) and analyzed by high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC–MS/MS). Carbamazepine, ciprofloxacin, ceftiofur, diclofenac, erythromycin, lincomycin, ofloxacin, pyrimthamine, spiramycin, sulfamethoxazole, sulfapyridine, testosterone, trimethoprim, and thiamphenicol were detected in all raw wastewaters in μg/L, whereas 45 PPCPs were below the detection limits (<0.02 μg/L) in all samples. Na`ur and Abu Nuseir WWTPs showed high PPCPs removal efficiencies in comparison with AL-Baqa`a, Salt, and Fuhais-Mahis WWTPs. Boqorreya spring showed signs of contamination by Salt WWTP effluents as a result of mixing. Irrigation with effluents showed higher carbamazepine concentrations in soils at the top soil layers (0 to 20 cm) in all farms than its concentrations at the root zone (20 to 40 cm) by using drip irrigation system with various plants. In plants, carbamazepine concentration was only detected in high concentration level in mint leaves. In the same farm, diclofenac concentration was detected only in olives and not in twigs and leaves, indicating a high rate of plant uptake especially during the olive’s growth period. Furthermore, plant fruits, leaves, and stems left on the farm after harvesting are generally consumed by cattle, which means entering the food chain of humans.

Contaminants of emerging concerns in recycled water: Fate and risks in agroecosystems

Recycled water (RW) has been increasingly recognized as a valuable source of water for alleviating the global water crisis. When RW is used for agricultural irrigation, many contaminants of emerging concern (CECs) are introduced into the agroecosystem. The ubiquity of CECs in field soil, combined with the toxic, carcinogenic, or endocrine-disrupting nature of some CECs, raises significant concerns over their potential risks to the environment and human health. Understanding such risks and delineating the fate processes of CECs in the water-soil-plant continuum contributes to the safe reuse of RW in agriculture. This review summarizes recent findings and provides an overview of CECs in the water-soil-plant continuum, including their occurrence in RW and irrigated soil, fate processes in agricultural soil, offsite transport including runoff and leaching, and plant uptake, metabolism, and accumulation. The potential ecological and human health risks of CECs are also discussed. Studies to date have shown limited accumulation of CECs in irrigated soils and plants, which may be attributed to multiple attenuation processes in the rhizosphere and plant, suggesting minimal health risks from RW-fed food crops. However, our collective understanding of CECs is rather limited and knowledge of their offsite movement and plant accumulation is particularly scarce for field conditions. Given a large number of CECs and their occurrence at trace levels, it is urgent to develop strategies to prioritize CECs so that future research efforts are focused on CECs with elevated risks for offsite contamination or plant accumulation. Irrigating specific crops such as feed crops and fruit trees may be a viable option to further minimize potential plant accumulation under field conditions. To promote the beneficial reuse of RW in agriculture, it is essential to understand the human health and ecological risks imposed by CEC mixtures and metabolites.

Assessing the risk from trace organic contaminants released via greywater irrigation to the aquatic environment

Onsite non-potable reuse of greywater reduces the energy costs associated with the transport of wastewater and the stress on traditional source waters. However, greywater contains trace organic contaminants (TOrCs) that can be harmful to the aquatic environment when released via irrigation. In this work, the risk associated with TOrCs was evaluated for two potential irrigation scenarios, the use of untreated greywater and the use of greywater treated via conventional activated sludge. Risk quotient (RQ) ratios were calculated using the maximum concentration of each compound in the untreated or treated greywater divided by the relevant aquatic predicted no effect concentration. The TOrCs with RQs > 0.1 or 1 were classified as moderate and high priority, respectively. A review of greywater literature showed that a total of 350 compounds have been detected, with 132 classified as moderate or high priority in untreated greywater. Post-treatment 44 TOrCs remained as high priority due to high concentrations in greywater and/or poor removal during treatment, but only 14 of them were detected in multiple geographic locations. The final list of 14 TOrCs includes plasticizers/flame retardants (di-(2-ethylhexyl) phthalate, bisphenol A, and triphenyl phosphate), surfactants/preservatives/fragrances (4-nonylphenol, benzyldimethyl dodecylammonium chloride, tonalide, methylparaben, and 2-6-di-tert-butyl-4-methylphenol), UV-filters (benzophenone-3 and octocrylene), and pharmaceuticals/antibiotics (acetaminophen, trimethoprim, caffeine, and triclosan). This subset of TOrCs would be useful surrogates to monitor during greywater treatment for irrigation as potential hazards for nearby aquatic environments.

Pharmaceuticals in edible crops irrigated with reclaimed wastewater: Evidence from a large survey in Israel

Pharmaceuticals and other contaminants of emerging concern (CECs) are continuously introduced into the agroecosystem via reclaimed wastewater irrigation, a common agricultural practice in water-scarce regions. Although reclaimed wastewater irrigated crops are sold and consumed, only limited information is available on the occurrence of pharmaceuticals and other CECs in edible produce. Here, we report data on CECs in irrigation water, soils, and crops collected from 445 commercial fields irrigated with reclaimed wastewater in Israel. The following produce were analyzed: leafy greens, carrot, potato, tomato, orange, tangerine, avocado, and banana. Pharmaceuticals and CECs were found in quantifiable levels in all irrigation water, soils, and plants (>99.6%). Leafy greens exhibited the largest number and the highest concentration of pharmaceuticals. Within the same crop, contamination levels varied due to wastewater source and quality of treatment, and soil characteristics. Anticonvulsants (carbamazepine, lamotrigine, and gabapentin) were the most dominant therapeutic group found in the reclaimed wastewater-soil-plant continuum. Antimicrobials were detected in ~85% of the water and soil samples, however they exhibited low detection frequencies and concentrations in produce. Irrigation with reclaimed wastewater should be limited to crops where the risk for pharmaceutical transfer to the food chain is minimal.

The transportation, transformation and (bio)accumulation of pharmaceuticals in the terrestrial ecosystem

Soil dwelling organisms, plants and many primary consumers in food webs face the challenge of exposure to contaminants of emerging concern (CECs) present in terrestrial systems, including thousands of substances derived from pharmaceutical and personal care products (PPCPs). The recent increase in the consumption of modern human or veterinary drugs has resulted in a surge of anthropogenic pharmaceuticals, frequently introduced into terrestrial environments via untreated/treated wastewater. Pharmaceuticals display diverse degradation and accumulation behaviours in receiving bodies, however their impact on soils has, at large, been overlooked. Details about adsorption, absorption, degradation and uptake behaviours, as well as the fate and actual environmental impact of pharmaceuticals are a prerequisite before the traditional transportation prediction models originally designed for the aquatic environment can be extrapolated to terrestrial systems. Without this knowledge, our ability for informed risk assessments and the resultant implementation of contamination management strategies of soils will remain limited. This review discusses the current knowledgebase pertaining the introduction of pharmaceuticals to soils via wastewater irrigation or the application of biosolids. The focus on the transportation, transformation and accumulation of pharmaceuticals through the food chain highlights the urgent need to strengthen our capabilities concerning their detection and characterization in the terrestrial ecosystem.

Coupling sprinkler freshwater irrigation with vegetable species selection as a sustainable approach for agricultural production in farmlands with a history of 50-year wastewater irrigation

Soil contamination and crop risks of heavy metal(loid)s are widely reported after the long-term irrigation of treated wastewater, causing an adverse influence on agricultural sustainability. Here, we collected soils after 50 years of wastewater irrigation to cultivate cabbage (Brassica pekinensis L.), rape (Brassica chinensis L.), carrots (Daucus carota L.), and potatoes (Solanum tuberosum L.), using surface and sprinkler irrigation with freshwater and wastewater. In general, we found the statistically insignificant influence of short-term freshwater irrigation on the soil and vegetable metal(loid) concentrations. Most of the vegetables had potential adverse health risks with the relatively lower risks in carrots and potatoes, and most of the risks were contributed by As and Cd. Nevertheless, we observed negligible health risks for all studied metal(loid)s in potatoes under the freshwater irrigations. Besides, compared to wastewater irrigations, freshwater irrigations produced lower Cd health risks in all four vegetable species. Sprinkler irrigation with freshwater was a favorable approach for reducing the uptake of metal(loid)s from soils and the metal(loid) concentrations in aboveground parts. Our study highlights the possibility of reducing vegetable metal(loid) risks in contaminated farmlands via a combined approach of coupling the short-term decrease in their levels in irrigation water with vegetable species selection.

Biodegradation kinetics of individual and mixture non-steroidal anti-inflammatory drugs in an agricultural soil receiving alkaline treated biosolids

Land application of biosolids is one potential source of pharmaceuticals and personal care products (PPCPs) into agricultural soils. Degradation is an important natural attenuation pathway that affects the fate and transport of PPCPs in the soil system and biosolids application could alter the process. The present study assessed the effect of individual and mixture compound environments on the biodegradation rate and half-life of three non-steroidal anti-inflammatory drugs (NSAIDs), naproxen (NPX), ibuprofen (IBF), and ketoprofen (KTF), in a loamy sand textured agricultural soil receiving an alkaline treated biosolid (ATB) amendment. A prolonged half-life of the target NSAIDs was determined for sterile soils and shorter half-lives in unsterile soils, indicating the loss of target compounds in all treatments was mainly attributed to biodegradation and followed first-order kinetics. IBF and NPX showed low to moderate persistence in soil and ATB amended soil, with half-lives ranging from 4.9 to 14.8 days, while KTF appeared to be highly persistent with an average half-life of 33 days. The order in which the target NSAIDs disappeared in both soil and ATB amended soil was: IBF > NPX > KTF, for both individual and mixture compound treatments. Soils that received the ATB amendment demonstrated inhibited degradation of NPX in all treatments, as well as IBF and KTF in individual compound treatment over the 14-day incubation study. We also observed an inhibition effect from the ATB amendment in sterile soil treatments. In mixture compound treatments, IBF degradation was inhibited in both soil and ATB amended soil. The degradation rate of KTF in mixture compound environment in soil was lower, while the opposite effects were observed in ATB amended soils. For NPX, the degradation was enhanced in mixture compound environment in ATB amended soil, while the same degradation rate of NPX was calculated in soil.

Leachability of endocrine disrupting chemicals (EDCs) in municipal sewage sludge: Effects of EDCs interaction with dissolved organic matter

In this study, experiments were performed to assess the significance of dissolved organic matter (DOM) on the leachability of four common EDCs, i.e., bisphenol A (BPA), 17α-ethinylestradiol (EE2), progesterone (PGT) and testosterone (TST), in municipal sewage sludge (MSS) under landfill conditions. The DOM was derived from two sources: MSS (MDOM), and natural soil represented by organic matter obtained from the Suwannee River (NDOM). Fluorescence excitation-emission matrix quenching combined with parallel factor analysis was adopted to characterize the interaction properties between the EDCs and DOM. The accumulative leachability of the target EDCs ranged from 0.09% (PGT) to 3.8% (TST). In particular, the leaching of BPA, EE2 and TST followed S-shaped curves, while PGT exhibited continuous leaching potential in untreated MSS. With the introduction of DOM, (i) the leachability of BPA and EE2 increased to 13.4% and 61.6%, respectively, whereas those of PGT and TST declined by 61.3% and 45.8%, respectively, and (ii) BPA, EE2 and PGT no longer reached leaching equilibrium but the S-shaped leaching property of TST persisted. The differential effects of MDOM and NDOM at identical concentrations on the EDCs leachability increased with curing time. BPA, EE2 and PGT quenched the MDOM fluorophores attributed to aromatic protein-like components. The fluorescence quenching of NDOM by BPA, EE2 and PGT was centered on soluble microbial by-product-like and humic-like substances. Compared with PGT, EE2 and BPA had greater capability for binding with DOM components largely via hydrophobic interactions, whereas PGT preferentially interacted with the DOM hydrophilic functionalities through specific interactions. TST had no binding capability but displayed potentials competing for sorption sites with DOM moieties. Our findings suggested that the management of MSS increased the risk of environmental contamination by EDCs for a long duration and that DOM was a useful indicator to predict the migration and transport properties of EDCs.

Reclaimed wastewater as a viable water source for agricultural irrigation: A review of food crop growth inhibition and promotion in the context of environmental change

The geographical and temporal distribution of precipitation has and is continuing to change with changing climate. Shifting precipitation will likely require adaptations to irrigation strategies, and because 35% of rainfed and 60% of irrigated agriculture is within 20 km of a wastewater treatment plant, we expect that the use of treated wastewater (e.g., reclaimed wastewater) for irrigation will increase. Treated wastewater contains various organic and inorganic substances that may have beneficial (e.g., nitrate) or deleterious (e.g., salt) effects on plants, which may cause a change in global food productivity should a large change to treated wastewater irrigation occur. We reviewed literature focused on food crop growth inhibition or promotion resulting from exposure to xenobiotics, engineered nanoparticles, nitrogen, and phosphorus, metals, and salts. Xenobiotics and engineered nanoparticles, in nearly all instances, were detrimental to crop growth, but only at concentrations much greater than would be currently expected in treated wastewater. However, future changes in wastewater flow and use of these compounds and particles may result in phytotoxicity, particularly for xenobiotics, as some are present in wastewater at concentrations within approximately an order of magnitude of concentrations which caused growth inhibition. The availability of nutrients present in treated wastewater provided the greatest overall benefit, but may be surpassed by the detrimental impact of salt in scenarios where either high concentrations of salt are directly deleterious to plant development (rare) or in scenarios where soils are poorly managed, resulting in soil salt accumulation.

Microplastics and pollutants in biosolids have contaminated agricultural soils: An analytical study and a proposal to cease the use of biosolids in farmlands and utilise them in sustainable bricks

Treated waste-water sludge (biosolids) are frequently recycled in agricultural lands; however, this practice has polluted soils with microplastics (MPs), nanoplastics (NPs), synthetics, heavy metals, pharmaceuticals and engineered nanoparticles. This study analyses many of the significant research outcomes in this area and proposes the urgent reduction of biosolids recycling in farmlands, aiming to eliminate their use altogether as soon as practicable, and instead, to utilise this material as a source of brick firing energy in the manufacturing of fired clay bricks and as a replacement for virgin brick soil. Based on a comprehensive data analysis, this study has calculated that in the European Union, the United States, China, Canada and Australia, approximately 26,042, 21,249, 13,660, 1,518 and 1,241 tonnes of microplastics, respectively, are added to farmlands annually as a result of biosolids application. The accumulation of microplastics produces detrimental effects on soil organisms and increases the accumulation of other micropollutants, such as heavy metals. The degradation of MPs over time is a source for the creation of nanoplastics, which pose a greater threat to ecosystems and human and animal health, as their size allows for their absorption into plant cells. On the other hand, the results of a comprehensive study at RMIT, including a comprehensive Life-Cycle Assessment, confirm that recycling biosolids in fired clay bricks (Bio-Bricks) is a promising sustainable alternative. This study proposes the mandatory addition of 7% biosolids in all brick manufacturing worldwide to utilize all biosolids production in fired clay bricks. This will reduce brick firing energy by over 12.5%.

Uptake of atenolol, carbamazepine and triclosan by crops irrigated with reclaimed water in a Mediterranean scenario

Water scarcity is a natural condition in the Mediterranean rim countries. In this region, reuse of reclaimed water (RW) from wastewater treatment plants (WWTPs) is becoming a potential source for highly water-demanding activities such as agriculture. However, the removal capacity of contaminants in regular WWTPs has been found to be limited. Considering a Mediterranean scenario, this research investigated the plant uptake and translocation of three representative pharmaceuticals and personal care products (PPCPs) typically present in RW samples from a WWTP located in an urban area in Spain, and assessed the potential risk to humans from plant consumption. The RW samples were collected and analyzed for three representative PPCPs (atenolol -ATN-, carbamazepine -CBZ- and triclosan -TCS-). The target contaminants were also spiked at two levels in the RW samples to consider two worst-case scenarios. Three plant models (lettuce, maize and radish) were grown outdoors and irrigated with four treatments: tap water; RW samples, and the two spiked RW samples. Generally speaking, results revealed an efficient root uptake for the three PPCPs regardless of plant species and fortification level, and suggested an interaction effect of treatment and plant organ. Different bioaccumulation and translocation potentials of the three PPCPs were seen into the aerial organs of the plants. Overall, these observations support the idea that factors including the physico-chemical properties of the PPCPs and physiological plant variables, could be responsible for the differential accumulation and translocation potentials observed. These variables could be critical for crops irrigated with RW in regions with extended dry seasons, high solar incidence and low annual rainfall such as those in the Mediterranean rim where plants are subjected to high transpiration rates. However, the results obtained from this experimental approach suggested a negligible risk to humans from consumption of edible plants irrigated with RW samples with presence of PPCPs, despite the fact that the three representative PPCPs under study accumulated efficiently in the plants.

Occurrence and human health risk assessment of pharmaceuticals and personal care products in real agricultural systems with long-term reclaimed wastewater irrigation in Beijing, China

Reclaimed wastewater (RW) is increasingly used to irrigate agricultural land and to alleviate agricultural water shortages worldwide. This usage has resulted in concerns about soil contamination by pharmaceuticals and personal care products (PPCPs) and the human health risks associated with dietary crop intake. In this study, we systematically analysed the occurrence and accumulation of 11 PPCPs and one active metabolite in soils and various crops (cucumber, eggplant, long bean and wheat) from realistic RW irrigation fields with different irrigation histories (20, 30 and 40 years) in Beijing and evaluated the human health risks associated with the consumption of these crops. The 11 PPCPs and one active metabolite were detected at concentrations ranging from 0.67 to 22.92 ng L^-1 in RW, 0.029-28.13 μg kg^-1 in irrigated soil, and <0.01-28.01 μg kg^-1 in crops. The concentrations of N4-acetyl-sulfamethoxazole and triclosan were higher than those of other PPCPs, with respective concentrations of 14.39-31.44 ng L^-1 and 15.93-26.23 ng L^-1 in RW, 10.92-23.29 μg kg^-1 and 20.22-28.13 μg kg^-1 in irrigated soil and 17.92-28.01 μg kg^-1 and 8.92-14.91 μg kg^-1 in crops. However, the estimated threshold of toxicological concern (TTC) and hazard quotient (HQ) values revealed that the concentrations of N4-acetyl-sulfamethoxazole and triclosan in crops irrigated with RW should be considered a de minimis risk to human health. The concentrations of 11 PPCPs and one active metabolite in soils and crops and the calculated fruit bioconcentration factors (BCFs) did not display obvious increases associated with the duration of RW irrigation in real agricultural systems (P > 0.05). The concentrations of the studied PPCPs in the RW used for irrigation followed different patterns from the concentrations detected in the irrigated soils and crops. Although the concentrations of sulfamethoxazole, sulfisoxazole, sulfamethazine and trimethoprim in RW were higher than those of many other studied PPCPs, their respective values in the irrigated soils and crops did not display a similar tendency. The uptake and accumulation of PPCPs varied among the crop species (P < 0.05). Although PPCPs were detected in eggplant, long bean and wheat (BCFs: not applicable-1.67, 0.03-1.35 and 0.01-5.01, respectively), PPCPs accumulated at increased levels in cucumber (BCFs 0.03-18.98). The estimated TTC and HQ values showed that the consumption of crops irrigated long-term with RW presents a de minimis risk to human health. However, further studies with more PPCPs and additional crop species need to be conducted, the synergistic effects of chemical mixtures of multiple PPCPs and the toxic effects of PPCP metabolites should be elucidated to obtain more reliable information on the safety of wastewater reuse for irrigation.

Enzyme response of activated sludge to a mixture of emerging contaminants in continuous exposure

The relevant information about the impacts caused by presence of emerging pollutants in mixtures on the ecological environment, especially on the more vulnerable compartments such as activated sludge (AS) is relatively limited. This study investigated the effect of ibuprofen (IBU) and triclosan (TCS), alone and in combination to the performance and enzymatic activity of AS bacterial community. The assays were carried out in a pilot AS reactor operating for two-weeks under continuous dosage of pollutants. The microbial activity was tracked by measuring oxygen uptake rate, esterase activity, oxidative stress and antioxidant enzyme activities. It was found that IBU and TCS had no acute toxic effects on reactor biomass concentration. TCS led to significant decrease of COD removal efficiency, which dropped from 90% to 35%. Continuous exposure to IBU, TCS and their mixtures increased the activities of glutathione s-transferase (GST) and esterase as a response to oxidative damage. A high increase in GST activity was associated with non-reversible toxic damage while peaks of esterase activity combined with moderate GST increase were attributed to an adaptive response.

Emerging investigator series: towards a framework for establishing the impacts of pharmaceuticals in wastewater irrigation systems on agro-ecosystems and human health

Use of reclaimed wastewater for agricultural irrigation is seen as an attractive option to meet agricultural water demands of a growing number of countries suffering from water scarcity. However, reclaimed wastewater contains pollutants which are introduced to the agro-environment during the irrigation process. While water reuse guidelines do consider selected classes of pollutants, they do not account for the presence of pollutants of emerging concern such as pharmaceuticals and the potential risks these may pose. Here we use source-pathway-receptor analysis (S-P-R) to develop a holistic framework for evaluating the impacts of pharmaceuticals, present in wastewater used for agricultural irrigation, on human and ecosystem health and evaluate the data availability for the framework components. The developed framework comprised of 34 processes and compartments but a good level of knowledge was available for only five of these suggesting that currently it is not possible to fully establish the impacts of pharmaceuticals in wastewater irrigation systems. To address this, work is urgently needed to understand the fate and transport of pharmaceuticals in arable soil systems and the effects of chronic low-level exposure to these substances on microbes, invertebrates, plants, wildlife and humans. In addition, research pertaining to the fate, uptake and effects of pharmaceutical mixtures and metabolites is lacking as well as data on bio-accessibility of pharmaceuticals after ingestion. Scientific advancements in the five areas prioritised in terms of future research are needed before we are able to fully quantify the agricultural and human health risks associated with reclaimed wastewater use.

Ranking of crop plants according to their potential to uptake and accumulate contaminants of emerging concern

The reuse of treated wastewater (TWW) for irrigation and the use of biosolids and manures as soil amendment constitute significant pathways for the introduction of the contaminants of emerging concern (CECs) to the agricultural environment. Consequently, CECs are routinely detected in TWW-irrigated agricultural soils and runoff from such sites, in biosolids- and manure-amended soils, and in surface and groundwater systems and sediments receiving TWW. Crop plants grown in such contaminated agricultural environments have been found to uptake and accumulate CECs in their tissues, constituting possible vectors of introducing CECs into the food chain; an issue that is presently considered of high priority, thus needing intensive investigation. This review paper aims at highlighting the responsible mechanisms for the uptake of CECs by plants and the ability of each crop plant species to uptake and accumulate CECs in its edible tissues, thus providing tools for mitigating the introduction of these contaminants into the food chain. Both biotic (e.g. plants' genotype and physiological state, soil fauna) and abiotic factors (e.g. soil pore water chemistry, physico-chemical properties of CECs, environmental perturbations) have been proven to influence the ability of crop plants to uptake and accumulate CECs. According to authors' estimates, based on the thorough elaboration of knowledge produced by existing relevant studies, the ability of crop plants to uptake and accumulate CECs decrease in the order of leafy vegetables > root vegetables > cereals and fodder crops > fruit vegetables; though, the uptake of CECs by important crop plants, such as fruit trees, is not yet evaluated. Overall, further studies must be performed to estimate the potential of crop plants to uptake and accumulate CECs in their edible tissues, and to characterize the risk for human health represented by their presence in human and livestock food products.

Degradation of Triclosan and Carbamazepine in Two Agricultural and Garden Soils with Different Textures Amended with Composted Sewage Sludge

Composted sewage sludge (CSS) has been extensively used in agriculture and landscaping, offering a practical solution for waste disposal. However, some pharmaceutical and personal care products (PPCPs) like triclosan (TCS) and carbamazepine (CBZ) have restricted its land application. In this study, CSS was added to agricultural soil and garden soil at 0%, 5%, 10%, and 25% (w/w soil), and 4 mL of TCS and CBZ stock solution (1000 mg/L in methanol) was spiked into soil amended with CSS of each bottle to arrive at the concentration of 10 mg/kg. Samples were then collected after incubation for 120 days and analyzed for concentrations and half-life (t1/2) of TCS and CBZ, and soil physicochemical properties, together with enzyme activities. The results showed that TCS was degraded completely during the incubation period. In contrast, only about 5.82⁻21.43% CBZ was degraded. CSS amendment inhibited TCS and CBZ degradation and prolonged t1/2 compared to the control, and the t1/2 of TCS and CBZ increased with CSS addition amount in all treatments except for CBZ in the garden soil amended with 10% CSS. Correlation studies showed a significantly positive relationship between t1/2 of TCS and CBZ and total organic carbon (TOC), while a significantly negative relationship between t1/2 of the two PPCPs and pH was observed. Alkaline phosphatase showed a significantly negative relationship with the Ct/C₀ of TCS in garden soil amended with 25% CSS and CBZ in the control. The urease activity was negatively correlated with the Ct/C₀ of TCS in 10% and 25% CSS treatments and CBZ in 10% CSS treatment for garden soil.

Mobility of pharmaceutical and personal care products in lime amended wastewater biosolids

Lime amendment of biosolids can produce large quantities of hydroxyl ions and increase biosolids pH. The mobility of some pharmaceutical and personal care products (PPCPs) is closely correlated with the pH of biosolids. In this study the mobility of six PPCPs: erythromycin, fluoxetine, carbamazepine, naproxen, gemfibrozil and triclosan, was measured in unamended and lime-amended biosolids over 63days. Biosolids were equilibrated either a at pH range of 5.5-11.5 or cured over a time period up to 63days. The mobility was calculated as the proportion of PPCPs associated with the soluble phase after a given equilibrium time or a curing period. In unamended biosolids the mobility of erythromycin, fluoxetine, gemfibrozil and triclosan decreased, the mobility of naproxen increased and the mobility of carbamazepine was almost unchanged over 63days of curing. Compared to unamended biosolids, lime addition increased the mobility of erythromycin and naproxen by 21.7% and 33.8% respectively, but suppressed the mobility of carbamazepine, fluoxetine, gemfibrozil and triclosan by up to 100% after 63days. The pH influence on hydrophobicity and speciation of PPCPs correlated well with the mobility of erythromycin and fluoxetine, but only partially correlated with the mobility of the other 4 compounds over the pH of 5.5-11.5. Attenuated total reflectance Fourier transformed infrared (ATR-FTIR) and emission-excitation matrices (EEMs) provided spectroscopic evidences showing that the increases in amide and carboxylic groups, the decrease in polysaccharides, and the increases in humic substances in dissolved organic matter (DOM) may be responsible for the changes in the PPCPs' mobility. The effects of lime amendment lasted for approximately a month. The results of this work suggest that lime amendment prevents some PPCPs from being dissolved in biosolids soluble phases, but may not "lock" all PPCPs into biosolids.

Composted biosolids and treated wastewater as sources of pharmaceuticals and personal care products for plant uptake: A case study with carbamazepine

Irrigation with treated wastewater (TWW) and application of biosolids to arable land expose the agro-environment to pharmaceuticals and personal care products (PPCPs) which can be taken up by crops. In this project, we studied the effect of a carrier medium (e.g., biosolids and TWW) on plant (tomato, wheat and lettuce) uptake, translocation and metabolism of carbamazepine as a model for non-ionic PPCPs. Plant uptake and bioconcentration factors were significantly lower in soils amended with biosolids compared to soils irrigated with TWW. In soils amended with biosolids and irrigated with TWW, the bioavailability of carbamazepine for plant uptake was moderately decreased as compared to plants grown in soils irrigated with TWW alone. While TWW acts as a continuous source of PPCPs, biosolids act both as a source and a sink for these compounds. Moreover, it appears that decomposition of the biosolids in the soil after amendment enhances their adsorptive properties, which in turn reduces the bioavailability of PPCPs in the soil environment. In-plant metabolism of carbamazepine was found to be independent of environmental factors, such as soil type, carrier medium, and absolute amount implemented to the soil, but was controlled by the total amount taken up by the plant.

Thiacloprid adsorption and leaching in soil: Effect of the composition of irrigation solutions

Pressure on groundwater resources has increased during the last decades due to the growing demand, especially in arid and semiarid regions, such as the Mediterranean basin, with frequent drought periods. In order to partially remediate this environmental problem of world concern, irrigation of agricultural lands with adequately treated wastewaters (TWW) is becoming a common management practice. The complex composition of these low-quality waters may influence the behavior of organic contaminants in soils. A calcareous soil with low organic carbon content was selected for the assessment of the adsorption and leaching of the neonicotinoid insecticide thiacloprid (THC). Different solutions were evaluated: TWW after a secondary treatment, a saline solution and solutions with a range of dissolved organic carbon concentration (DOC, 3-300mgL^-1). The addition of an organic fertilizer (fertiormont) to the soil was also assessed, in an attempt to reduce THC mobility. Sorption of thiacloprid, a relatively polar pesticide, was similar under all the conditions considered, though an adsorption decrease was observed when DOC concentration increased. The transport of THC through soil columns was retarded with all the treatments, with the lower effects corresponding to TWW and the saline solution. Addition of fertiormont and irrigation with DOC at 3mgL^-1 resulted in a reduction of pesticide leached (34% and 38%, respectively) in comparison with the control (66%), but surprisingly not for DOC at high concentration (55%), possibly due to co-elution of the pesticide with DOC. Therefore the transport of polar compounds, like THC, could be affected by the composition of the irrigation solutions, altering their impact to environmental water resources.

The potential implications of reclaimed wastewater reuse for irrigation on the agricultural environment: The knowns and unknowns of the fate of antibiotics and antibiotic resistant bacteria and resistance genes - A review

The use of reclaimed wastewater (RWW) for the irrigation of crops may result in the continuous exposure of the agricultural environment to antibiotics, antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs). In recent years, certain evidence indicate that antibiotics and resistance genes may become disseminated in agricultural soils as a result of the amendment with manure and biosolids and irrigation with RWW. Antibiotic residues and other contaminants may undergo sorption/desorption and transformation processes (both biotic and abiotic), and have the potential to affect the soil microbiota. Antibiotics found in the soil pore water (bioavailable fraction) as a result of RWW irrigation may be taken up by crop plants, bioaccumulate within plant tissues and subsequently enter the food webs; potentially resulting in detrimental public health implications. It can be also hypothesized that ARGs can spread among soil and plant-associated bacteria, a fact that may have serious human health implications. The majority of studies dealing with these environmental and social challenges related with the use of RWW for irrigation were conducted under laboratory or using, somehow, controlled conditions. This critical review discusses the state of the art on the fate of antibiotics, ARB and ARGs in agricultural environment where RWW is applied for irrigation. The implications associated with the uptake of antibiotics by plants (uptake mechanisms) and the potential risks to public health are highlighted. Additionally, knowledge gaps as well as challenges and opportunities are addressed, with the aim of boosting future research towards an enhanced understanding of the fate and implications of these contaminants of emerging concern in the agricultural environment. These are key issues in a world where the increasing water scarcity and the continuous appeal of circular economy demand answers for a long-term safe use of RWW for irrigation.

Review of the ecotoxicological effects of emerging contaminants to soil biota

In recent years, emerging contaminants (e.g. pesticides and their metabolites, pharmaceuticals, personal and house care products, life-style compounds, food additives, industrial products and wastes, as well as nanomaterials) have become a problem to the environment. In fact, the cumulative use of a panoply of chemical substances in agriculture, industrial activities, in our homes and in health care services has led to their recent appearance in detectable levels in soils, surface, and groundwater resources, with unpredictable consequences for these ecosystems. Few data exist regarding the toxicity and potential for bioaccumulation in biota. When available, data were obtained only for some representatives of the main groups of chemical substances, and for a limited number of species, following non-standard protocols. This makes difficult the calculation of predicted no effect concentrations (PNEC) and the existence of sufficient data to set limits for their release into the environment. This is particularly concerning for the soil compartment, since only recently the scientific community, regulators, and the public have realised the importance of protecting this natural resource and its services to guarantee the sustainability of terrestrial ecosystems and human well-being. In this context, this review paper aims to identify the major groups of soil emerging contaminants, their sources, pathways and receptors, and in parallel to analyse existing ecotoxicological data for soil biota.

Simultaneous Determination of Fluoroquinolones and Sulfonamides Originating from Sewage Sludge Compost

A simultaneous method for quantitative determination of traces of fluoroquinolones (FQs) and sulfonamides (SAs) in edible plants fertilized with sewage sludge was developed. The compounds were extracted from the plants by rapid and simple liquid extraction followed by extracts clean-up using solid phase extraction. The eluent additive 1,1,1,3,3,3-hexafluoro-2-propanol was used for liquid chromatographic detection to achieve separation of structurally similar antimicrobials like ciprofloxacin and norfloxacin. Identification and quantification of the compounds were performed using high-performance liquid chromatography with electrospray ionization mass spectrometry in selected reaction monitoring mode. Method was validated and extraction recoveries of FQs and SAs ranged from 66% to 93%. The limit of quantifications was from 5 ng/g in the case of ofloxacin to 40 ng/g for norfloxacin. The method precision ranged from 1.43% to 2.61%. The developed novel method was used to evaluate the plats antimicrobial uptake (potato (Solanum tuberosum L.), carrot (Daucus carota L.), lettuce (Lactuca sativa L.), and wheat (Triticum vulgare L.)) from soil and migration of the analytes inside the plants.

Long-term wastewater irrigation of vegetables in real agricultural systems: Concentration of pharmaceuticals in soil, uptake and bioaccumulation in tomato fruits and human health risk assessment

Wastewater (WW) reuse for vegetable crops irrigation is regularly applied worldwide. Such a practice has been found to allow the uptake of pharmaceutical active compounds (PhACs) by plants and their subsequent entrance to the food web, representing an important alternative pathway for the exposure of humans to PhACs, with potential health implications. Herein we report the impacts of the long-term (three consecutive years) WW irrigation of a tomato crop with two differently treated effluents under real agricultural conditions, on (1) the soil concentration of selected PhACs (i.e. diclofenac, DCF; sulfamethoxazole, SMX; trimethoprim, TMP), (2) the bioaccumulation of these PhACs in tomato fruits, and (3) the human risks associated with the consumption of WW-irrigated fruits. Results revealed that the concentration of the studied PhACs in both the soil and tomato fruits varied depending on the qualitative characteristics of the treated effluent applied and the duration of WW irrigation. The PhAC with the highest soil concentration throughout the studied period was SMX (0.98 μg kg^-1), followed by TMP (0.62 μg kg^-1) and DCF (0.35 μg kg^-1). DCF was not found in tomato fruits harvested from WW-irrigated plants during the first year of the study. However, DCF displayed the highest fruit concentration (11.63 μg kg^-1) throughout the study (as a result of prolonged WW irrigation), followed by SMX (5.26 μg kg^-1) and TMP (3.40 μg kg^-1). The calculated fruit bioconcentration factors (BCF_F) were extremely high for DCF in the 2nd (108) and 3rd year (132) of the experimental period, with the respective values for SMX (0.5-5.4) and TMP (0.2-6.4) being significantly lower. The estimated threshold of toxicity concern (TTC) and hazard quotients (HQ) values revealed that the consumption of fruits harvested from tomato plants irrigated for long period with the WW applied for irrigation under field conditions in this study represent a de minimis risk to human health. However, more studies need to be performed in order to obtain more solid information on the safety of WW reuse for irrigation.

Impact of Veterinary Pharmaceuticals on the Agricultural Environment: A Re-inspection

The use of veterinary pharmaceuticals (VPs) is a result of growing animal production. Manure, a great crop fertilizer, contains a significant amount of VPs. The investigation of VPs in manure is prevalent, because of the potential risk for environmental organisms, as well as human health. A re-evaluation of the impact of veterinary pharmaceuticals on the agricultural environment is needed, even though several publications appear every year. The aim of this review was to collate the data from fields investigated for the presence of VPs as an inevitable component of manure. Data on VP concentrations in manure, soils, groundwater and plants were collected from the literature. All of this was connected with biotic and abiotic degradation, leaching and plant uptake. The data showed that the sorption of VPs into soil particles is a process which decreases the negative impact of VPs on the microbial community, the pollution of groundwater, and plant uptake. What was evident was that most of the data came from experiments conducted under conditions different from those in the environment, resulting in an overestimation of data (especially in the case of leaching). The general conclusion is that the application of manure on crop fields leads to a negligible risk for plants, bacteria, and finally humans, but in future every group of compounds needs to be investigated separately, because of the high divergence of properties.

Colloid-Mediated Transport of Pharmaceutical and Personal Care Products through Porous Media

Pharmaceutical and personal care products (PPCPs) enter soils through reclaimed water irrigation and biosolid land applications. Colloids, such as clays, that are present in soil may interact with PPCPs and thus affect their fate and transport in the subsurface environment. This study addresses the influence of soil colloids on the sorption and transport behaviors of PPCPs through laboratory column experiments. Results show that the affinities of PPCPs for colloids vary with their molecular chemistry and solution ionic strength. The presence of colloids promotes the breakthrough of ciprofloxacin (over 90% sorbed on colloids) from ~4% to 30–40%, and the colloid-facilitated effect was larger at lower ionic strength (e.g., 2 mM). In comparison, the net effect of colloids on the transport of tetracycline (~50% sorbed on colloids) could be facilitation or inhibition, depending on solution chemistry. This dual effect of colloids is primarily due to the opposite response of migration of dissolved and colloid-bound tetracycline to the change in solution ionic strength. Colloids could also facilitate the transport of ibuprofen (~10% sorbed on colloids) by ~50% due likely to exclusion of dispersion pathways by colloid straining. This study suggests that colloids are significant carriers or transport promoters of some PPCPs in the subsurface environment and could affect their off-site environmental risks.

Fate of carbamazepine, its metabolites, and lamotrigine in soils irrigated with reclaimed wastewater: Sorption, leaching and plant uptake

Irrigation with reclaimed wastewater may result in the ubiquitous presence of pharmaceutical compounds (PCs) and their metabolites in the agroecosystem. In this study, we focused on two highly persistent anticonvulsant drugs, lamotrigine and carbamazepine and two of its metabolites (EP-CBZ and DiOH-CBZ), aiming to elucidate their behavior in agricultural ecosystem using batch and lysimeter experiments. Sorption of the studied compounds by soils was found to be governed mainly by the soil organic matter level. Sorption affinity of compounds to soils followed the order lamotrigine > carbamazepine > EP-CBZ > DiOH-CBZ. Sorption was reversible, and no competition between sorbates in bi-solute systems was observed. The results of the lysimeter studies were in accordance with batch experiment findings, demonstrating accumulation of lamotrigine and carbamazepine in top soil layers enriched with organic matter. Detection of carbamazepine and one of its metabolites in rain-fed wheat previously irrigated with reclaimed wastewater, indicates reversibility of their sorption, resulting in their potential leaching and their availability for plant uptake. This study demonstrates the long-term implication of introduction of PCs to the agroecosystem.

Transport of organic contaminants in subsoil horizons and effects of dissolved organic matter related to organic waste recycling practices

Compost amendment on agricultural soil is a current practice to compensate the loss of organic matter. As a consequence, dissolved organic carbon concentration in soil leachates can be increased and potentially modify the transport of other solutes. This study aims to characterize the processes controlling the mobility of dissolved organic matter (DOM) in deep soil layers and their potential impacts on the leaching of organic contaminants (pesticides and pharmaceutical compounds) potentially present in cultivated soils receiving organic waste composts. We sampled undisturbed soil cores in the illuviated horizon (60-90 cm depth) of an Albeluvisol. Percolation experiments were made in presence and absence of DOM with two different pesticides, isoproturon and epoxiconazole, and two pharmaceutical compounds, ibuprofen and sulfamethoxazole. Two types of DOM were extracted from two different soil surface horizons: one sampled in a plot receiving a co-compost of green wastes and sewage sludge applied once every 2 years since 1998 and one sampled in an unamended plot. Results show that DOM behaved as a highly reactive solute, which was continuously generated within the soil columns during flow and increased after flow interruption. DOM significantly increased the mobility of bromide and all pollutants, but the effects differed according the hydrophobic and the ionic character of the molecules. However, no clear effects of the origin of DOM on the mobility of the different contaminants were observed.

Root Uptake of Pharmaceuticals and Personal Care Product Ingredients

Crops irrigated with reclaimed wastewater or grown in biosolids-amended soils may take up pharmaceuticals and personal care product ingredients (PPCPs) through their roots. The uptake pathways followed by PPCPs and the propensity for these compounds to bioaccumulate in food crops are still not well understood. In this critical review, we discuss processes expected to influence root uptake of PPCPs, evaluate current literature on uptake of PPCPs, assess models for predicting plant uptake of these compounds, and provide recommendations for future research, highlighting processes warranting study that hold promise for improving mechanistic understanding of plant uptake of PPCPs. We find that many processes that are expected to influence PPCP uptake and accumulation have received little study, particularly rhizosphere interactions, in planta transformations, and physicochemical properties beyond lipophilicity (as measured by Kow). Data gaps and discrepancies in methodology and reporting have so far hindered development of models that accurately predict plant uptake of PPCPs. Topics warranting investigation in future research include the influence of rhizosphere processes on uptake, determining mechanisms of uptake and accumulation, in planta transformations, the effects of PPCPs on plants, and the development of predictive models.

Sorption and biodegradation characteristics of the selected pharmaceuticals and personal care products onto tropical soil

In the present study, the sorption and biodegradation characteristics of five pharmaceutical and personal care products (PPCPs), including acetaminophen (ACT), carbamazepine (CBZ), crotamiton (CTMT), diethyltoluamide (DEET) and salicylic acid (SA), were studied in laboratory-batch experiments. Sorption kinetics experimental data showed that sorption systems under this study were more appropriately described by the pseudo second-order kinetics with a correlation coefficient (R2)>0.98. Sorption equilibrium data of almost all target compounds onto soil could be better described by the Freundlich sorption isotherm model. The adsorption results showed higher soil affinity for SA, following by ACT. Results also indicated a slight effect of pH on PPCP adsorption with lower pH causing lower adsorption of compounds onto the soil except for SA at pH 12. Moreover, adsorption of PPCPs onto the soil was influenced by natural organic matter (NOM) since the higher amount of NOM caused lower adsorption to the soil. Biodegradation studies of selected PPCPs by indigenous microbial community present in soil appeared that the removal rates of ACT, SA and DEET increased with time while no effect had been observed for the rest. This study suggests that the CBZ and CTMT can be considered as suitable chemical sewage indicators based on their low sorption affinity and high resistance to biodegradation.

What happens when pharmaceuticals meet colloids

Pharmaceuticals (PCs) have been widely detected in natural environment due to agricultural application of reclaimed water, sludge and animal wastes. Their potential risks to various ecosystems and even to human health have caused great concern; however, little was known about their environmental behaviors. Colloids (such as clays, metal oxides, and particulate organics) are kind of substances that are active and widespread in the environment. When PCs meet colloids, their interaction may influence the fate, transport, and toxicity of PCs. This review summarizes the progress of studies on the role of colloids in mediating the environmental behaviors of PCs. Synthesized results showed that colloids can adsorb PCs mainly through ion exchange, complexation and non-electrostatic interactions. During this process the structure of colloids and the stability of PCs may be changed. The adsorbed PCs may have higher risks to induce antibiotic resistance; besides, their transport may also be altered considering they have great chance to move with colloids. Solution conditions (such as pH, ionic strength, and cations) could influence these interactions between PCs and colloids, as they can change the forms of PCs and alter the primary forces between PCs and colloids in the solution. It could be concluded that PCs in natural soils could bind with colloids and then co-transport during the processes of irrigation, leaching, and erosion. Therefore, colloid-PC interactions need to be understood for risk assessment of PCs and the best management practices of various ecosystems (such as agricultural and wetland systems).

Plant uptake of pharmaceutical and personal care products from recycled water and biosolids: a review

Reuse of treated wastewater for agricultural irrigation is growing in arid and semi-arid regions, while increasing amounts of biosolids are being applied to fields to improve agricultural outputs. These historically under-utilized resources contain "emerging contaminants", such as pharmaceutical and personal care products (PPCPs), which may enter agricultural soils and potentially contaminate food crops. In this review, we summarize recent research and provide a detailed overview of PPCPs in the soil-plant systems, including analytical methods for determination of PPCPs in plant tissues, fate of PPCPs in agricultural soils receiving treated wastewater irrigation or biosolids amendment, and plant uptake of PPCPs under laboratory and field conditions. Mechanisms of uptake and translocation of PPCPs and their metabolisms in plants are also reviewed. Field studies showed that the concentration levels of PPCPs in crops that were irrigated with treated wastewater or applied with biosolids were very low. Potential human exposure to PPCPs through dietary intake was discussed. Information gaps and questions for future research have been identified in this review.

Sustainable approaches for minimizing biosolids production and maximizing reuse options in sludge management: A review

Sludge generation during wastewater treatment is inevitable even with proper management and treatment. Yet proper handling and disposal of sludge are still challenging in terms of treatment cost, presence of recalcitrant contaminants of concern, sanitary issues, and public acceptance. Conventional disposal methods (i.e. landfilling, incineration) have created concerns in terms of legislative restrictions and community perception, incentivizing consideration of substitute sludge management options. Furthermore, with proper treatment, biosolids from sludge, rich in organic materials and nutrients, could be utilizable as fertilizer. Despite the challenges of dealing with sludge, no review has dealt with integrated source reduction and reuse as the best sustainable management practices for sludge treatment. In this review, we present two main approaches as potentially sustainable controls: (i) pretreatment for minimizing extensive sludge treatment, and (ii) recycling and reuse of residual sludge. Drawing on these approaches, we also suggest strategies for efficient pretreatment mechanisms and residual reuse, presenting ideas for prospective future research.

Multi-year and short-term responses of soil ammonia-oxidizing prokaryotes to zinc bacitracin, monensin, and ivermectin, singly or in combination

A field experiment was initiated whereby a series of replicated plots received annual applications of ivermectin, monensin, and zinc bacitracin, either singly or in a mixture. Pharmaceuticals were added at concentrations of 0.1 mg/kg soil or 10 mg/kg soil. The authors collected soil samples in 2013, before and after the fourth annual application of pharmaceuticals. In addition, a 30-d laboratory experiment was undertaken with the same soil and same pharmaceuticals, but at concentrations of 100 mg/kg soil. The impact of the pharmaceuticals on nitrification rates, on the abundance of ammonia-oxidizing bacteria (AOB), and on the abundance of ammonia-oxidizing archaea (AOA) was assessed. None of the pharmaceuticals at 0.1 mg/kg had any effect on nitrification. Referenced to control soil, nitrification was accelerated in soil exposed to 100 mg/kg zinc bacitracin or 10 mg/kg of the pharmaceutical mixture, but none of the treatments inhibited nitrification. Neither AOB abundance nor AOA abundance was affected by the pharmaceuticals at 0.1 mg/kg. At 10 mg/kg, monensin, zinc bacitracin, and a mixture of all 3 pharmaceuticals suppressed the abundance of AOB, and zinc bacitracin and the mixture increased AOA abundance. The decrease in AOB abundance and increase in AOA abundance when exposed to 10 mg/kg soil suggests that AOB are more sensitive to these chemicals and that AOA populations can expand to occupy the partially vacated niche.

An uncertainty and sensitivity analysis applied to the prioritisation of pharmaceuticals as surface water contaminants from wastewater treatment plant direct emissions

In this study, the concentration probability distributions of 82 pharmaceutical compounds detected in the effluents of 179 European wastewater treatment plants were computed and inserted into a multimedia fate model. The comparative ecotoxicological impact of the direct emission of these compounds from wastewater treatment plants on freshwater ecosystems, based on a potentially affected fraction (PAF) of species approach, was assessed to rank compounds based on priority. As many pharmaceuticals are acids or bases, the multimedia fate model accounts for regressions to estimate pH-dependent fate parameters. An uncertainty analysis was performed by means of Monte Carlo analysis, which included the uncertainty of fate and ecotoxicity model input variables, as well as the spatial variability of landscape characteristics on the European continental scale. Several pharmaceutical compounds were identified as being of greatest concern, including 7 analgesics/anti-inflammatories, 3 β-blockers, 3 psychiatric drugs, and 1 each of 6 other therapeutic classes. The fate and impact modelling relied extensively on estimated data, given that most of these compounds have little or no experimental fate or ecotoxicity data available, as well as a limited reported occurrence in effluents. The contribution of estimated model input variables to the variance of freshwater ecotoxicity impact, as well as the lack of experimental abiotic degradation data for most compounds, helped in establishing priorities for further testing. Generally, the effluent concentration and the ecotoxicity effect factor were the model input variables with the most significant effect on the uncertainty of output results.

Biodegradability of pharmaceutical compounds in agricultural soils irrigated with treated wastewater

Pharmaceutical compounds (PCs) are introduced into agricultural soils via irrigation with treated wastewater (TWW). Our data show that carbamazepine, lamotrigine, caffeine, metoprolol, sulfamethoxazole and sildenafil are persistent in soils when introduced via TWW. However, other PCs, namely diclofenac, ibuprofen, bezafibrate, gemfibrozil and naproxen were not detected in soils when introduced via TWW. This is likely due to rapid degradation as confirmed in our microcosm studies where they exhibited half-lives (t1/2) between 0.2-9.5 days when soils were spiked at 50 ng/g soil and between 3 and 68 days when soils were spiked at 5000 ng/g soil. The degradation rate and extent of PCs observed in microcosm studies were similar in soils that had been previously irrigated with TWW or fresh water. This suggests that pre-exposure of the soils to PCs via irrigation with TWW does not enhance their biodegradation. This suggests that PCs are probably degraded in soils via co-metabolism.

Contaminants of emerging concern in fresh leachate from landfills in the conterminous United States

To better understand the composition of contaminants of emerging concern (CECs) in landfill leachate, fresh leachate from 19 landfills was sampled across the United States during 2011. The sampled network included 12 municipal and 7 private landfills with varying landfill waste compositions, geographic and climatic settings, ages of waste, waste loads, and leachate production. A total of 129 out of 202 CECs were detected during this study, including 62 prescription pharmaceuticals, 23 industrial chemicals, 18 nonprescription pharmaceuticals, 16 household chemicals, 6 steroid hormones, and 4 plant/animal sterols. CECs were detected in every leachate sample, with the total number of detected CECs in samples ranging from 6 to 82 (median = 31). Bisphenol A (BPA), cotinine, and N,N-diethyltoluamide (DEET) were the most frequently detected CECs, being found in 95% of the leachate samples, followed by lidocaine (89%) and camphor (84%). Other frequently detected CECs included benzophenone, naphthalene, and amphetamine, each detected in 79% of the leachate samples. CEC concentrations spanned six orders of magnitude, ranging from ng L(-1) to mg L(-1). Industrial and household chemicals were measured in the greatest concentrations, composing more than 82% of the total measured CEC concentrations. Maximum concentrations for three household and industrial chemicals, para-cresol (7 020 000 ng L(-1)), BPA (6 380 000 ng L(-1)), and phenol (1 550 000 ng L(-1)), were the largest measured, with these CECs composing 70% of the total measured CEC concentrations. Nonprescription pharmaceuticals represented 12%, plant/animal sterols 4%, prescription pharmaceuticals 1%, and steroid hormones <1% of the total measured CEC concentrations. Leachate from landfills in areas receiving greater amounts of precipitation had greater frequencies of CEC detections and concentrations in leachate than landfills receiving less precipitation.