Removal of anti-inflammatory/analgesic pharmaceuticals from urban wastewater in a pilot-scale A2O system: Linking performance and microbial population dynamics to operating variables

Global insight into the occurrence, treatment technologies and ecological risk of emerging contaminants in sanitary sewers: Effects of the SARS-CoV-2 coronavirus pandemic

The SARS-CoV-2 pandemic caused changes in the consumption of prescribed/non-prescribed drugs and the population's habits, influencing the detection and concentration of emerging contaminants (ECs) in sanitary sewage and harming environmental and health risks. Therefore, the present work sought to discuss current literature data on the effects of the "COVID-19 pandemic factor" on the quality of raw sewage produced over a five-year period (2018-2019: pre-pandemic; 2020-2022: during the pandemic) and biological, physical, chemical and hybrid treatment technologies, influencing factors in the removal of ECs and potential ecological risks (RQs). Seven hundred thirty-one publications correlating sewage and COVID-19 were identified: 184 pre-pandemic and 547 during the pandemic. Eight classes and 37 ECs were detected in sewage between 2018 and 2022, with the "COVID-19 pandemic factor" promoting an increase in estrogens (+31,775 %), antibiotics (+19,544 %), antiepileptics and antipsychotics (+722 %), pesticides (+200 %), analgesics, anti-inflammatories and anticoagulants (+173 %), and stimulant medications (+157 %) in sanitary sewage. Among the treatment systems, aerated reactors integrated into biomembranes removed >90 % of cephalexin, clarithromycin, ibuprofen, estrone, and 17β-estradiol. The absorption, adsorption, and biodegradation mechanisms of planted wetland systems contributed to better cost-benefit in reducing the polluting load of sewage ECs in the COVID-19 pandemic, individually or integrated into the WWTP. The COVID-19 pandemic factor increased the potential ecological risks (RQs) for aquatic organisms by 40 %, with emphasis on clarithromycin and sulfamethoxazole, which changed from negligible risk and low risk to (very) high risk and caffeine with RQ > 2500. Therefore, it is possible to suggest that the COVID-19 pandemic intensified physiological, metabolic, and physical changes to different organisms in aquatic biota by ECs during 2020 and 2022.

Microbial indicators of efficient performance in an anaerobic/anoxic/aerobic integrated fixed-film activated sludge (A2O-IFAS) and a two-stage mesophilic anaerobic digestion process

An analysis of the community structure, diversity and population dynamics of Bacteria and Archaea in the suspended and attached biomass fractions of a pilot-scale anaerobic/anoxic/aerobic integrated fixed-film activated sludge (A²O-IFAS) was executed. Along with this, the effluents of the acidogenic (AcD) and methanogenic (MD) digesters of a two-stage mesophilic anaerobic (MAD) system treating the primary sludge (PS) and waste activated sludge (WAS) generated by the A²O-IFAS were also analyzed. Non-metric multidimensional scaling (MDS) and Biota-environment (BIO-ENV) multivariate analyses were performed to link population dynamics of Bacteria and Archaea to operating parameters and removal efficiencies of organic matter and nutrients, in search of microbial indicators associated with optimal performance. In all samples analyzed, Proteobacteria, Bacteroidetes and Chloroflexi were the most abundant phyla, while the hydrogenotrophic methanogens Methanolinea, Methanocorpusculum and Methanobacterium were the predominant archaeal genera. BIO-ENV analysis disclosed strong correlations between the population shifts observed in the suspended and attached bacterial communities of the A²O-IFAS and the removal rates of organic matter, N and P. It is noteworthy that the incorporation of carriers combined with a short sludge retention time (SRT = 4.0 ± 1.0 days) enhanced N removal performance of the A²O by favoring the enrichment of bacterial genera able to denitrify (Bosea, Dechloromonas, Devosia, Hyphomicrobium, Rhodobacter, Rhodoplanes, Rubrivivax, and Sulfuritalea) in the attached biomass fraction. In addition, operation at short SRT enabled the generation of a highly biodegradable WAS, which enhanced the biogas and methane yields in the two-stage MAD. An increase in the relative abundance of Acetobacteroides (uncultured Blvii28 wastewater-sludge group of Rikenellaceae family) correlated positively with the volatile solids removal rate (%VSR), CH₄ recovery rate and %CH₄ in the biogas (r > 0.8), supporting their relevance for an efficient methanogenesis in two-stage systems.

Integrated full-scale solar CPC/UV-LED–filtration system as a tertiary treatment in a conventional WWTP for agricultural reuse purposes

Today, the emergence of increasingly restrictive treatment and reuse policies make the implementation of full-scale tertiary treatment, capable of improving the quality of water, a priority. Full-scale TiO2 photocatalysis systems are resulting in a promising option, since TiO2 is commercially available. However, questions such as how to work continuously during day/night irradiation cycle, or the removing of TiO2 in outlet flow are still unresolved. In this work, a full-scale system integrating a solar CPC/UV-LED step combined with commercial microfiltration membranes was installed in a conventional WWTP for agricultural reuse purposes. After optimization, 0.5 g/L of catalyst and combined SOLAR + UV-LED showing the highest pharmaceutical removal percentages, while a self-designed UV-LED included in the own reaction tank resulting in higher efficiencies compared with commercial lamps. Longer membrane surface area decreased fouling problems in the system. However, 60 min of irradiation time was necessary to reach the most restrictive water quality values according with (EU 2020/741). After optimization step, total costs were reduced by 45%. However, it was shown that a reduction in operating and maintenance costs, along with the development of more effective and economical commercial filtration membranes is a key factor; therefore, working on these aspects is essential in the treated water cost reduction.

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Improving biological removal of pharmaceutical active compounds and estrogenic activity in a mesophilic anaerobic osmotic membrane bioreactor treating municipal sewage

The contamination of water sources by pharmaceutically active compounds (PhACs) and their effect on aquatic communities and human health have become an environmental concern worldwide. Membrane bioreactors (MBRs) are an alternative to improve biological removal of recalcitrant organic compounds from municipal sewage. Their efficiency can be increased by using high retention membranes such as forward osmosis (FO) and membrane distillation (MD). Thus, this research aimed to evaluate the performance of an anaerobic osmotic MBR coupled with MD (OMBR-MD) in the treatment of municipal sewage containing PhACs and estrogenic activity. A submerged hybrid FO-MD module was integrated into the bioreactor. PhACs removal was higher than 96% due to biological degradation, biosorption and membrane retention. Biological removal of the PhACs was affected by the salinity build-up in the bioreactor, with reduction in biodegradation after 32 d. However, salinity increment had little or no effect on biosorption removal. The anaerobic OMBR-MD removed >99.9% of estrogenic activity, resulting in a distillate with 0.14 ng L^-1 E2-eq, after 22 d, and 0.04 ng L^-1 E2-eq, after 32 d. OMBR-MD treatment promoted reduction in environmental and human health risks from high to low, except for ketoprofen, which led to medium acute environmental and human health risks. Carcinogenic risks were reduced from unacceptable to negligible, regarding estrogenic activity. Thus, the hybrid anaerobic OMBR-MD demonstrated strong performance in reducing risks, even when human health is considered.

The photocatalytic degradation kinetics of the anti-inflammatory drug ibuprofen in aqueous solution under UV/TiO2 system and neural networks modeling

In this study, the kinetic degradation of the anti-inflammatory drug Ibuprofen in aqueous solution by heterogeneous TiO2 photocatalytic was investigated. The data obtained were used for training an artificial neural network. Preliminary experiments of photolysis and adsorption were carried out to assess their contribution to the photocatalytic degradation. Both, direct photolysis and adsorption of Ibuprofen are very low-efficient processes (15,83% and 23,88%, respectively). The degradation efficiency was significantly elevated with the addition of TiO2 Catalyst (>94%). The photocatalytic degradation followed a pseudo-first-order reaction according to the L-H model. The hydroxyl radicals and photo-hole (h+‏) were found to contribute to the Ibuprofen removal. The higher the initial concentration of Ibuprofen resulted in the lower percentage of degradation. This can be credited to the fact that the created photon and radicals were constant. The higher the initial concentration of Ibuprofen the fewer radicals were shared for each Ibuprofen molecular and so the lower percentage of degradation. The maximum photoactivity from the available light is accomplished when the concentration of catalyst reaches to 1 g/L (0.8 g), which was adopted as the optimal amounts. Compared to the removal of ibuprofen, the mineralization was relatively lower. This decrease is due to the organic content of the treated solution, which is mainly composed of recalcitrant intermediate products. The network was planned as a Levenberg-Marquardt algorithm with three layer, four neurons in the input layer, fourteen neurons in the hidden layer and one neuron in the output layer (4:14:1). The artificial neural network was trained until the MSE value between the simulated data and the experimental results was 10−5. The best results (R 2 = 0.999 and MSE = 1.5 × 10−4) were obtained with a log sigmoid transfer function at hidden layer and a linear transfer function at output layer.

Biodegradability, environmental risk assessment and ecological footprint in wastewater technologies for pharmaceutically active compounds removal

Several studies have investigated the removal of pharmaceutically active compounds (PhACs) by wastewater treatment technologies due to the risk that these compounds pose to the environment. In this sense, advanced biological processes have been developed for micropollutants removal, such as membrane bioreactors and moving bed biofilm reactors. Thus, this review holistically evaluated the biodegradation of 18 environmentally hazardous PhACs. Biological processes were assessed including removal efficiencies, environmental risk, and ecological footprint (consumption of resources and energy, atmospheric emissions, and waste generation). The maximum concentration of PhACs for a low or negligible risk scenario in treated wastewater and the potential of biological processes to meet this goal were assessed. Among the evaluated PhACs, the most biodegradable was paracetamol, while the most recalcitrant was diclofenac. Combination of conventional processes and advanced biological processes proved to be the most efficient way to remove several PhACs, mainly the osmotic membrane bioreactor.

Insights into the acute effect of anti-inflammatory drugs on activated sludge systems with high solids retention time

The increase in the occurrence of the pharmaceuticals in the environmental compartments is becoming emerging concern as it reflects their inefficient treatment in the wastewater treatment plants which are the main sources of these micropollutants. Non-steroidal anti-inflammatory drugs (NSAIDs) are one of the most commonly prescribed and frequently detected pain medications in wastewater treatment plants. A lab scale sequencing batch reactor (SBR) was operated for seven months and acute inhibitory effect of NSAIDs on activated sludge was tested with respirometry. Culture amendment with different concentrations of NSAIDs in the presence as well as absence of nitrification inhibitor resulted in considerable variation in the oxygen uptake rate (OUR) profiles. The decrease in OUR and nitrate production rate governed with reduced heterotrophic and nitrification activity. The kinetics of half saturation for growth and maximum autotrophic growth rates are determined to be affected negatively by the acute impact of anti-inflammatory pharmaceuticals even at the environmentally relevant concentrations. High removal of tested NSAIDs was observed even for the first time introduce with these compounds.

Insights into the removal of pharmaceutically active compounds from sewage sludge by two-stage mesophilic anaerobic digestion

The removal efficiencies (REs) of twenty-seven pharmaceutically active compounds (PhACs) (eight analgesic/anti-inflammatories, six antibiotics, four β-blockers, two antihypertensives/diuretics, three lipid regulators and four psychiatric drugs) were evaluated in a pilot-scale two-stage mesophilic anaerobic digestion (MAD) system treating thickened sewage sludge from a pilot-scale A²O™ wastewater treatment plant (WWTP) which was fed with wastewater from the pre-treatment of the full-scale WWTP Murcia Este (Murcia, Spain). The MAD system was long-term operated using two different sets of sludge retention times (SRTs) for the acidogenic (AcD) and methanogenic (MD) digesters (phase I, 2 and 12 days; and phase II, 5 and 24 days, in AcD and MD, respectively). Quantitative PCR (qPCR) and Illumina MiSeq sequencing were used to estimate the absolute abundance of Bacteria, Archaea, and Fungi and investigate the structure, diversity and population dynamics of their communities in the AcD and MD effluents. The extension of the SRT from 12 (phase I) to 24 days (phase II) in the MD was significantly linked with an improved removal of carbamazepine, clarithromycin, codeine, gemfibrozil, ibuprofen, lorazepam, and propranolol. The absolute abundances of total Bacteria and Archaea were higher in the MD regardless of the phase, while the diversity of bacterial and archaeal communities was lower in phase II, in both digesters. Non-metric multidimensional scaling (MDS) plots showed strong negative correlations among phyla Proteobacteria and Firmicutes and between genera Methanosaeta and Methanosarcina throughout the full experimental period. Strong positive correlations were revealed between the relative abundances of Methanospirillum and Methanoculleus and the methanogenesis performance parameters (volatile solids removal, CH₄ recovery rate and %CH₄ in the biogas), which were also related to longer SRT. The REs of several PhACs (naproxen, ketoprofen, ofloxacin, fenofibrate, trimethoprim, and atenolol) correlated positively (r > 0.75) with the relative abundances of specific bacterial and archaeal groups, suggesting their participation in biodegradation/biotransformation pathways.

Recent Trends in Pharmaceuticals Removal from Water Using Electrochemical Oxidation Processes

Nowadays, the research on the environmental applications of electrochemistry to remove recalcitrant and priority pollutants and, in particular, drugs from the aqueous phase has increased dramatically. This literature review summarizes the applications of electrochemical oxidation in recent years to decompose pharmaceuticals that are often detected in environmental samples such as carbamazapine, sulfamethoxazole, tetracycline, diclofenac, ibuprofen, ceftazidime, ciprofloxacin, etc. Similar to most physicochemical processes, efficiency depends on many operating parameters, while the combination with either biological or other physicochemical methods seems particularly attractive. In addition, various strategies such as using three-dimensional electrodes or the electrosynthesis of hydrogen peroxide have been proposed to overcome the disadvantages of electrochemical oxidation. Finally, some guidelines are proposed for future research into the applications of environmental electrochemistry for the degradation of xenobiotic compounds and micropollutants from environmental matrices. The main goal of the present review paper is to facilitate future researchers to design their experiments concerning the electrochemical oxidation processes for the degradation of micropollutants/emerging contaminants, especially, some specific drugs considering, also, the existing limitations of each process.

Comparative overview of advanced oxidation processes and biological approaches for the removal pharmaceuticals

Nowadays, pharmaceuticals are the center of significant environmental research due to their complex and highly stable bioactivity, increasing concentration in the water streams and high persistence in aquatic environments. Conventional wastewater treatment techniques are generally inadequate to remove these pollutants. Aiming to tackle this issue effectively, various methods have been developed and investigated on the light of chemical, physical and biological procedures. Increasing attention has recently been paid to the advanced oxidation processes (AOPs) as efficient methods for the complete mineralization of pharmaceuticals. Their high operating costs compared to other processes, however, remain a challenge. Hence, this review summarizes the current and state of art related to AOPs, biological treatment and their effective exploitation for the degradation of various pharmaceuticals and other emerging molecules present in wastewater. The review covers the last decade with a particular focus on the previous five years. It is further envisioned that this review of advanced oxidation methods and biological treatments, discussed herein, will help readers to better understand the mechanisms and limitations of these methods for the removal of pharmaceuticals from the environment. In addition, we compared AOPs and biological treatments for the disposal of pharmaceuticals from the point of view of cost, effectiveness, and popularity of their use. The exploitation of coupling AOPs and biological procedures for the degradation of pharmaceuticals in wastewater was also presented. It is worthy of note that an integrated AOPs/biological system is essential to reach the complete degradation of pharmaceuticals; other advantages of this hybrid technique involve low energy cost, an efficient degradation process and generation of non-toxic by-products.

Biodegradation of Emerging Pharmaceuticals from Domestic Wastewater by Membrane Bioreactor: The Effect of Solid Retention Time

Although conventional biological treatment plants can remove basic pollutants, they are ineffective at removing recalcitrant pollutants. Membrane bioreactors contain promising technology and have the advantages of better effluent quality and lower sludge production compared to those of conventional biological treatment processes. In this study, the removal of pharmaceutical compounds by membrane bioreactors under different solid retention times (SRTs) was investigated. To study the effect of SRT on the removal of emerging pharmaceuticals, the levels of pharmaceuticals were measured over 96 days for the following retention times: 20, 30, and 40-day SRT. It was found that the 40-day SRT had the optimum performance in terms of the pharmaceuticals’ elimination. The removal efficiencies of the chemical oxygen demand (COD) for each selected SRT were higher than 96% at steady-state conditions. The highest degradation efficiency was observed for paracetamol. Paracetamol was the most removed compound followed by ranitidine, atenolol, bezafibrate, diclofenac, and carbamazepine. The microbial community at the phylum level was also analyzed to understand the biodegradability of pharmaceuticals. It was noticed that the Proteobacteria phylum increased from 46.8% to 60.0% after 96 days with the pharmaceuticals. The Actinobacteria class, which can metabolize paracetamol, carbamazepine, and atenolol, was also increased from 9.1% to 17.9% after adding pharmaceuticals. The by-products of diclofenac, bezafibrate, and carbamazepine were observed in the effluent samples.

The Abundance and Diversity of Fungi in a Hypersaline Microbial Mat from Guerrero Negro, Baja California, México

The abundance and diversity of fungi were evaluated in a hypersaline microbial mat from Guerrero Negro, México, using a combination of quantitative polymerase chain reaction (qPCR) amplification of domain-specific primers, and metagenomic sequencing. Seven different layers were analyzed in the mat (Layers 1–7) at single millimeter resolution (from the surface to 7 mm in depth). The number of copies of the 18S rRNA gene of fungi ranged between 10⁶ and 10⁷ copies per g mat, being two logarithmic units lower than of the 16S rRNA gene of bacteria. The abundance of 18S rRNA genes of fungi varied significantly among the layers with layers 2–5 mm from surface contained the highest numbers of copies. Fifty-six fungal taxa were identified by metagenomic sequencing, classified into three different phyla: Ascomycota, Basidiomycota and Microsporidia. The prevalent genera of fungi were Thermothelomyces, Pyricularia, Fusarium, Colletotrichum, Aspergillus, Botrytis, Candida and Neurospora. Genera of fungi identified in the mat were closely related to genera known to have saprotrophic and parasitic lifestyles, as well as genera related to human and plant pathogens and fungi able to perform denitrification. This research suggests that fungi in the mat may participate in nutrient recycling, modification of community composition through parasitic activities, and denitrification.

Evaluation of the Abundance of Fungi in Wastewater Treatment Plants Using Quantitative PCR (qPCR)

Assessment of the abundance of fungi in environmental samples by quantitative PCR (qPCR) of community DNA is often a difficult task due to biases introduced during PCR amplification, resulting from the differences associated with length polymorphism and the varying number of copies of the rRNA operon among fungal species, the lack of specificity of the primers targeting the different regions of the rRNA operon, or their insufficient coverage of the fungal lineages. To overcome those limitations, it is crucial to test and select the specific primers sets which provide the more accurate approximation to the quantification of the targeted fungal populations in a given set of samples. Fungi are a significant fraction of the microbiota in wastewater treatment plants (WWTPs), but the activated sludge microbial communities comprise many other eukaryotic microorganisms whose molecular markers are often coamplified by primers initially designed as fungal-specific. Here, the use of the FungiQuant primer set is recommended for the quantification of fungal molecular markers (18S rRNA genes) by qPCR in activated sludge samples and the full protocol is described.

A sustainability anti-infective pharmaceutical wastewater treatment technology: multi-stage vertical variable diameter membrane bioreactor with DO online controlling

The proper choice of dissolved oxygen (DO) is important in aerobic treatment. In this paper, a multi-stage vertical variable diameter membrane bioreactor was developed to treat pharmaceutical wastewater containing 6-APA and ceftriaxone sodium. In the 180 days of operation, the performance of COD, BOD₅, 6-APA, ceftriaxone sodium removal, sludge index, and microbial enzyme activity under different DOs (from 0.5 to 6.0 mg/L) were investigated. The results showed that the optimal range of DO was 1.5-2.1 mg/L, and the highest removal rates of COD and BOD₅ were observed 87.3%±2.4% and 95.3%±1.8%, the corresponding effluent COD and BOD₅ were 189 mg/L and 24 mg/L, respectively. To reduce the energy consumption and ensure stability of DO in the reactor, a control strategy based on an improved differential evolution BP fuzzy neural network was built and found that the performance and cost of the controlled DO were improved effectively than that of uncontrolled DO.

From Laboratory Tests to the Ecoremedial System: The Importance of Microorganisms in the Recovery of PPCPs-Disturbed Ecosystems

The presence of a wide variety of emerging pollutants in natural water resources is an important global water quality challenge. Pharmaceuticals and personal care products (PPCPs) are known as emerging contaminants, widely used by modern society. This objective ensures availability and sustainable management of water and sanitation for all, according to the 2030 Agenda. Wastewater treatment plants (WWTP) do not always mitigate the presence of these emerging contaminants in effluents discharged into the environment, although the removal efficiency of WWTP varies based on the techniques used. This main subject is framed within a broader environmental paradigm, such as the transition to a circular economy. The research and innovation within the WWTP will play a key role in improving the water resource management and its surrounding industrial and natural ecosystems. Even though bioremediation is a green technology, its integration into the bio-economy strategy, which improves the quality of the environment, is surprisingly rare if we compare to other corrective techniques (physical and chemical). This work carries out a bibliographic review, since the beginning of the 21st century, on the biological remediation of some PPCPs, focusing on organisms (or their by-products) used at the scale of laboratory or scale-up. PPCPs have been selected on the basics of their occurrence in water resources. The data reveal that, despite the advantages that are associated with bioremediation, it is not the first option in the case of the recovery of systems contaminated with PPCPs. The results also show that fungi and bacteria are the most frequently studied microorganisms, with the latter being more easily implanted in complex biotechnological systems (78% of bacterial manuscripts vs. 40% fungi). A total of 52 works has been published while using microalgae and only in 7% of them, these organisms were used on a large scale. Special emphasis is made on the advantages that are provided by biotechnological systems in series, as well as on the need for eco-toxicological control that is associated with any process of recovery of contaminated systems.

Ecofriendly laccases treatment to challenge micropollutants issue in municipal wastewaters

In this study, a multidisciplinary approach investigated the enzymatic degradation of micropollutants in real, not modified, municipal wastewaters of a plant located in Italy. Stir Bar Sorptive Extraction combined to Gas Chromatography-Mass Spectrometric detection (SBSE-GC-MS) was applied to profile targeted pollutants in wastewaters collected after the primary sedimentation (W1) and the final effluent (W2). Fifteen compounds were detected at ng/L - μg/L, including pesticides, personal care products (PCPs) and drugs. The most abundant micropollutants were bis(2-ethylhexyl) phthalate, diethyl phthalate and ketoprofen. Laccases of Trametes pubescens MUT 2400 were very active against all the target micropollutants: except few cases, their concentration was reduced more than 60%. Chemical analysis and environmental risk do not always come together. To verify whether the treated wastewaters can represent a stressor for the aquatic ecosystem, toxicity was also evaluated. Raphidocelis subcapitata and Lepidium sativum tests showed a clear ecotoxicity reduction, even though they did not evenly respond. Two in vitro tests (E-screen test and MELN assay) were used to evaluate the estrogenic activity. Treatments already operating in the plant (e.g. activated sludge) partially reduced the estradiol equivalent concentration, and it was almost negligible after the laccases treatment. The results of this study suggest that laccases of T. pubescens are promising biocatalysts for the micropollutants transformation in wastewaters and surface waters.

Monitoring the release of anti-inflammatory and analgesic pharmaceuticals in the receiving environment

The occurrence of anti-inflammatory and analgesic pharmaceuticals (AIAPs) in the effluents of 16 hospitals, influent and effluent of wastewater treatment plant (WWTP), the contribution and mass load of each hospital to WWTP influent, and the removal efficiencies in WWTP were investigated. Environmental risk was also evaluated by toxicity tests using organisms from three different trophic levels. Acetaminophen had the highest concentration in summer and winter samples, followed by ketoprofen, ibuprofen, and naproxen. The total daily load of AIAPs detected in influent of WWTP was 1677 mg/day/1000 inhabitants in summer and 5074 mg/day/1000 inhabitants in winter. The contribution of 16 hospitals to the total AIAP load in influent of WWTP was 11.30% in summer and 7.09% in winter. The highest mass loads were calculated as 203 mg/bed.day in general hospital in summer and 300 mg/bed.day in pediatric hospital in winter. The removal efficiencies of AIAPs in WWTP ranged between 13% and 100% in summer and 0.88% and 99% in winter. WWTP is not sufficient to remove all the AIAPs. Diclofenac (in summer), mefenamic acid, indomethacin, and phenylbutazone exhibited poor removal below 50%. The effluents of the WWTP exhibited a low risk for fish and Daphnia magna and an insignificant risk for algae.

Acetaminophen micropollutant: Historical and current occurrences, toxicity, removal strategies and transformation pathways in different environments

Acetaminophen (ACT) is commonly used as a counter painkiller and nowadays, it is increasingly present in the natural water environment. Although its concentrations are usually at the ppt to ppm levels, ACT can transform into various intermediates depending on the environmental conditions. Due to the complexity of the ACT degradation products and the intermediates, it poses a major challenge for monitoring, detection and to propose adequate treatment technologies. The main objectives of this review study were to assess (i) the occurrences and toxicities, (2) the removal technologies and (3) the transformation pathways and intermediates of ACT in four environmental compartments namely wastewater, surface water, ground water, and soil/sediments. Based on the review, it was observed that the ACT concentrations in wastewater can reach up to several hundreds of ppb. Amongst the different countries, China and the USA showed the highest ACT concentration in wastewater (≤300 μg/L), with a very high detection frequency (81-100%). Concerning surface water, the ACT concentrations were found to be at the ppt level. Some regions in France, Spain, Germany, Korea, USA, and UK comply with the recommended ACT concentration for drinking water (71 ng/L). Notably, ACT can transform and degrade into various metabolites such as aromatic derivatives or organic acids. Some of them (e.g., hydroquinone and benzoquinone) are toxic to human and other life forms. Thus, in water and wastewater treatment plants, tertiary treatment systems such as advanced oxidation, membrane separation, and hybrid processes should be used to remove the toxic metabolites of ACT.

Distribution, Removal, and Risk Assessment of Pharmaceuticals and Their Metabolites in Five Sewage Plants

The extensive use of pharmaceuticals and personal care products (PPCPs) leads to a continuous increase of their presence in urban wastewater. These pollutants are discharged into natural waters and pose a threat to human health and the ecological environment. This study focused on five sewage treatment plants in three cities of China’s Yangtze River Delta as research sites to study the distribution and degradation of drugs and their conversion products in wastewater. The concentration of target compounds in the water ranged from 0 to 510.8 ng/L, and both positive and negative removal rates occurred during the treatment. Acetaminophen (ACE) and ibuprofen (IPF) can be completely removed in the biological treatment stage. The addition of flocculants and sand filtration has a positive effect on the removal of naproxen (NPX) and bezafibrate (BZB). Ultraviolet disinfection is beneficial for the removal of antipyrine (ATP) and diclofenac (DCF). A small amount of PPCPs were found in the sludge and particulate matter, which had little effect on removal. Finally, the risk quotients were used to evaluate the harmfulness of the PPCPs detected in the effluent to the ecological environment, and the results showed that there was little hazard.

Linking microbial diversity and population dynamics to the removal efficiency of pharmaceutically active compounds (PhACs) in an anaerobic/anoxic/aerobic (A2O) system

The removal efficiencies (REs) of nineteen pharmaceutically active compounds (PhACs) (six antibiotics-clarithromycin, ofloxacin, sulfadiazine, sulfamethazine, sulfamethoxazole and trimethoprim -, four β-blockers -atenolol, metoprolol, propranolol and sotalol-, two antihypertensives/diuretics -furosemide and hydrochlorothiazide-, three lipid regulators -bezafibrate, fenofibrate and gemfibrozil-, and four psychiatric medications -carbamazepine, diazepam, lorazepam and paroxetine) were ascertained in a pilot-scale anaerobic/anoxic/aerobic (A²O) system treating urban wastewater, long term operated during two experimental phases using different sets of environmental conditions and operating parameters. Illumina MiSeq sequencing was used to investigate the structure, diversity and population dynamics of bacteria, archaea and fungi communities in the activated sludge. The results showed that mixed liquor suspended solids (MLSS) and food-to-microorganisms ratio (F/M) were operational parameters significantly influencing the REs of five of the analyzed PhACs in the A²O system. Biota-environment (BIO-ENV) analysis revealed strong correlations between population shifts of the activated sludge community and the REs of PhACs of the different pharmaceutical families. Increased REs of clarithromycin, furosemide, bezafibrate and gemfibrozil were concomitant to higher relative abundances of bacterial phylotypes classified within the Rhodobacteraceae and Sphingomonadaceae (Alphaproteobacteria), while those of Betaproteobacteria, Chloroflexi and Methanomethylovorans (Euryarchaea) correlated positively with the REs of up to seven PhACs belonging to different therapeutic groups.

Abundance of total and metabolically active Candidatus Microthrix and fungal populations in three full-scale wastewater treatment plants

The abundances of total and metabolically active populations of Candidatus Microthrix and Fungi were evaluated by quantitative PCR (qPCR) and retrotranscribed qPCR of ribosomal molecular markers in three different full-scale wastewater treatment plants (WWTPs), in absence of bulking/foaming episodes. Significant differences of the abundance of rDNAs and rRNAs of Candidatus Microthrix and Fungi were observed among the three WWTPs. The average relative abundances of 16S rDNA copies of Candidatus Microthrix to those of Bacteria ranged 3.4-8.9%. Biota-environment analysis (BIO-ENV) demonstrated that the number of copies of both 16S rDNA and rRNA of Candidatus Microthrix increased at longer hydraulic and solids' retention times and with higher nitrate concentrations in the activated sludge. The abundance of Candidatus Microthrix correlated strongly and positively with the removal efficiencies of organic matter and total nitrogen in the tested WWTPs, highlighting the role of these particular microbial group in the performance of these engineered systems.