Possible effect of submarine groundwater discharge on the pollution of coastal water: Occurrence, source, and risks of endocrine disrupting chemicals in coastal groundwater and adjacent seawater influenced by reclaimed water irrigation

Concentration of steroid hormones in sediment of surface water resources in China: systematic review and meta-analysis with ecological risk assessment

The risk quotient (RQ) related to Estrone (E1), 17β-E2 (E2), Estriol (E3) and 17α-ethynylestradiol (EE2) in sediment of water resources in China was calculated using Monte Carlo Simulation (MCS) method. Fifty-four papers with 64 data-reports included in our study. The rank order of steroid hormones in sediment based on log-normal distribution in MCS was E1 (3.75 ng/g dw) > E3 (1.53 ng/g dw) > EE2 (1.38 ng/g dw) > E2 (1.17 ng/g dw). According to results, concentration of steroid hormones including E1, E2 and E3 in sediment of Erhai lake, northern Taihu lake and Dianchi river was higher than other locations. The rank order of steroid hormones based on percentage high risk (RQ > 1) was EE2 (87.00%) > E1 (70.00%) > E2 (62.99%) > E3 (11.11%). Hence, contamination control plans for steroid hormones in sediment of water resources in China should be conducted continuously.

Steroid hormones in surface water resources in China: systematic review and meta-analysis and probabilistic ecological risk assessment

A Search was conducted in international databases including Scopus, PubMed, Embase, and Web of Science from 10 January 2005 to 15 January 2023. The risk quotient (RQ) of Estrone (E1), 17β-E2 (E2), and Estriol (E3) on the surface water resources of China was calculated by Monte Carlo Simulation (MCS) technique. The rank order of steroid hormones based on pooled (weighted average) concentration in surface water was E3 (2.15 ng/l) > E2 (2.01 ng/l) > E1 (1.385 ng/l). The concentration of E1 in Dianchi lake (236.50.00 ng/l), 17β-E2 in Licun river (78.50 ng/l), and E3 in Dianchi lake (103.1 ng/l) were higher than in other surface water resources in China. RQ related to E1, 17β-E2 and E3 in 68.00%, 88.89% and 3.92% of surface water resources were high ecological risk, respectively. Therefore, carrying out source control plans for steroid hormones in surface water sources should be conducted continuously.

Stable and reproducible MIP-ECL sensors for ultra-sensitive and accurate quantitative detection of Estrone

Estrone (E1), as an endogenous estrogen, has a variety of physiological functions in human body and is of great significance to human health. On the other hand, it is a widely distributed and highly disturbing environmental endocrine disruptor in water. Therefore, there is an urgent need to develop a sensitive, rapid, and inexpensive method for the on-site determination of E1, which is not only for clinical diagnosis and treatment, but also for the investigation and monitoring of endogenous estrogen pollution in environmental water. In this study, Ru(bpy)3 2+/MWCNTs/Nafion/gold electrodes were prepared by surface electrostatic adsorption and ion exchange. A molecularly imprinted membrane (MIP) with the capability to recognize E1 molecules was prepared by sol-gel method, and the electrodes were modified with MIP to form an electrochemical luminescence sensor (MIP-ECL). This method simultaneously possesses ECL's advantage of high sensitivity and MIP's advantage of high selectivity. Moreover, the addition of carboxylated multi-walled carbon nanotubes (MWCNT-COOH) improved the functionalization of the gold electrode surface and increased the binding sites of MIP. Meanwhile, the good conductivity of MWCNTs promoted electron transfer and further improved the sensitivity of the sensor. The sensor showed a wide linear interval in which the E1 concentrations can range from 0.1 μg/L to 200 μg/L, along with a high linear correlation coefficient (R 2 = 0.999). The linear regression equation of the sensor was Y = 243.64x-79.989, and the detection limit (LOD) was 0.0047 μg/L. To validate our sensor, actual samples were also measured by the reference method (LC-MS/MS), and it was found that the relative deviation of quantitative results of the two different methods was less than 4.1%. This indicates that the quantitative results obtained by this sensor are accurate and can be used for rapid in situ determination of E1 in clinical samples and environmental water.

Review of Endocrine Disrupting Compounds (EDCs) in China's water environments: Implications for environmental fate, transport and health risks

Endocrine Disrupting Compounds (EDCs) are ubiquitous in soil and water system and have become a great issue of environmental and public health concern since the 1990s. However, the occurrence and mechanism(s) of EDCs' migration and transformation at the watershed scale are poorly understood. A review of EDCs pollution in China's major watersheds (and comparison to other countries) has been carried out to better assess these issues and associated ecological risks, compiling a large amount of data. Comparing the distribution characteristics of EDCs in water environments around the world and analyzing various measures and systems for managing EDCs internationally, the significant insights of the review are: 1) There are significant spatial differences and concentration variations of EDCs in surface water and groundwater in China, yet all regions present non-negligible ecological risks. 2) The hyporheic zone, as a transitional zone of surface water and groundwater interaction, can effectively adsorb and degrade EDCs and prevent the migration of high concentrations of EDCs from surface water to groundwater. This suggests that more attention needs to be paid to the role played by critical zones in water environments, when considering the removal of EDCs in water environments. 3) In China, there is a lack of comprehensive and effective regulations to limit and reduce EDCs generated during human activities and their discharge into the water environment. 4) To prevent the deterioration of surface water and groundwater quality, the monitoring and management of EDCs in water environments should be strengthened in China. This review provides a thorough survey of scientifically valid data and recommendations for the development of policies for the management of EDCs in China's water environment.

Hydrochemical evolution characteristics and genesis of groundwater under long-term infiltration (2007-2018) of reclaimed water in Chaobai River, Beijing

The reuse of reclaimed water (RW) for river ecological restoration in global water-shortage regions has inevitably brought some potential risks for groundwater. However, little is known about the effects of reclaimed water on the hydrochemical evolution of groundwater especially under long-term infiltration conditions. Herein, 11-years monitoring data (2007-2018) of reclaimed water and groundwater were adopted to analyze the characteristics and genesis of groundwater hydrochemical evolution under long-term infiltration of reclaimed water from Jian River to Chaobai River in Beijing. The results showed that the hydrochemical components in groundwater totally performed a significant increase in Na⁺, Cl^-, and K⁺and decrease in Ca²⁺, Mg²⁺, and HCO₃^- concentration after long-term infiltration of reclaimed water. Meanwhile, a significant hydrochemical evolution difference between the groundwater of Jian River and Chaobai River was observed. In Jian River, the hydrochemical type in groundwater shifted gradually from HCO₃-Ca·Mg to the type of HCO₃·Cl-Na·Ca approaching reclaimed water. In contrast, the hydrochemical evolution in the Chaobai River shows an obvious opposite trend from HCO₃-Ca·Mg to HCO₃·Cl-Na·Mg and finally deviating reclaimed water type of Cl·HCO₃·SO₄-Na. PHREEQC simulation indicated that the differences in hydrochemical evolution were mediated synergically by sediment thickness and geochemical processes (e.g. mixing and sulfate reduction). In such mediators, thinner sediment and strong mixing in the Jian River were confirmed to be the genesis of groundwater hydrochemical evolution progressively approaching reclaimed water. Different from the Jian River, multiple regression analyses revealed that the genesis of groundwater hydrochemical evolution in the Chaobai River was divided into two stages according to the increase of sediment thickness. Reclaimed water quality and infiltration amount are the leading proposed cause in the initial stage (2007-2008) due to thinner sediment formation, contributing 53.5% and 29.8% within the 95% confidence interval, respectively. Subsequently, the rise in sediment thickness is proved to play a crucial role in groundwater hydrochemical evolution trend away from reclaimed water (2009-2018), with a contribution of 41.6% within the 95% confidence interval. It is mainly attributed to the reduced reclaimed water infiltration rate and favorable sulfate reduction conditions. These findings advance our understanding on groundwater hydrochemical evolution under long-term infiltration of reclaimed water and also guide future prediction of evolution trends.

Comprehensive insights into profiles and bacterial sources of intracellular and extracellular antibiotic resistance genes in groundwater

Antibiotic resistance genes (ARGs), especially last-resort ARGs (LARGs), are receiving extensive attention as emerging environmental contaminants in groundwater. However, their prevalent intracellular and extracellular patterns and bacterial sources in groundwater remain unclear. Herein, groundwater samples were collected in Tianjin, and characterized based on the profiles of intracellular ARGs (iARGs) and extracellular ARGs (eARGs), as well as the resident bacterial communities and extracellular DNA (eDNA)-releasing bacterial communities. The quantitative real-time PCR assays showed that eARGs presented fewer subtypes than iARGs and generally displayed lower detection frequencies than the corresponding iARGs. Similarly, LARGs exhibited lower detection frequencies than common ARGs, but the total abundance showed no significant differences between them. Genes vanA and bla_VIM were the observed dominant LARGs, and aadA was the observed common ARG independent of location inside or outside the bacteria. Furthermore, the top 10 phyla showed much difference between the main eDNA-releasing bacteria and the dominant resident bacteria. Proteobacteria was the predominant resident bacterial phyla while dominating the source of eDNA in groundwater. Despite representing a minor portion of the abundance in the resident bacteria, Actinobacteriota, Acidobacteriota, and Chloroflex surprisingly accounted for a large majority of eDNA release. Co-occurrence patterns among persistent ARGs, the resident bacteria, and eDNA-releasing bacteria revealed that the dominant common iARG aadA and intracellular LARGs bla_VIM and vanA had significant positive correlations with Methylobacterium_Methylorubrum and Shewanella. Meanwhile, the dominant extracellular LARG bla_VIM may be released by bacteria belonging to at least five genera, including Ellin6067, Bifidobacterium, Blautia, Veillonella, and Dechloromonas. Collectively, the findings of this study extend our understanding regarding the distribution of ARGs and their bacterial sources in groundwater, and indicate the serious pollution of LARGs in groundwater, which poses potential risks to public health.

Occurrence, source apportionment and potential risks of selected PPCPs in groundwater used as a source of drinking water from key urban-rural settings of Pakistan

BACKGROUND

Pharmaceuticals and personal care products (PPCPs) are emerging contaminants that have been extensively used in present time to improve the living standards. Their persistence in water resources due to various anthropogenic sources such as wastewater treatment plants, pharmaceutical industries, and runoff from agricultural and livestock farms has not only threaten aquatic life but their occurrence in groundwater has also raised concerns related to humans' wellbeing.

METHODS

Considering this as a neglected area of research in Pakistan, a systematic monitoring study was designed to investigate their occurrence, sources, and potential environmental and human health risks in groundwater from urban-rural areas of six cities. Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry (UHPLC-MS/MS) was used to analyze the collected samples preceded by solid-phase extraction.

RESULTS

Overall, 8 out of 11 selected PPCPs were detected in groundwater samples with detection frequency ranging from 5.5-65%. Their concentrations ranged from below limit of detection (<LOD) to 1961 ng/L. The overall mean concentrations of detected PPCPs were found below 100 ng/L. The highest mean concentration was reported for Ibuprofen (154 ng/L) in Rawalpindi/Islamabad. Results of PCA-MLR revealed that domestic wastewater discharge (76.4%) was the dominant source contributing to PPCPs contamination in groundwater. Followed by mixed source (pharmaceutical & hospital waste) 17.8%, and rural discharge/animal husbandry 5.8%. No appreciable risk to human health upon exposure to detected PPCPs via drinking water was anticipated. However, environmental risk assessment indicated moderate risk posed to P. subcapitata (RQ = 0.98) and D. magna (RQ = 0.2) by ibuprofen.

CONCLUSION

The current study reports the first evidence of PPCPs occurrence in groundwater in Pakistan. Reporting their occurrence in groundwater is a fundamental initial step to inform public-health decisions concerning sewage systems and drinking water quality. Hence, comprehensive monitoring programs are required to further investigate contamination of emerging contaminants in groundwater and their associated risks.

Fate of land-based antibiotic resistance genes in marginal-sea sediment: Territorial differentiation and corresponding drivers

No large-scale investigations on fate of land-based antibiotic resistance genes (ARGs) in marginal sea have been reported. The Yellow Sea which is an important marginal sea was selected to investigate the fate, territorial differentiation, and drivers of target ARGs in marginal-sea sediments. ARGs might spread from land to sea with the average absolute abundance of total ARGs in marine/coastal sediments reaching 1.23 × 10⁴/9.79 × 10⁴ copies/g. The Yellow Sea Cold Water Mass was firstly observed to possibly have potential inhibition effect on occurrence of ARGs in marine sediments. Marine sediments showed significant difference from coastal sediments by considering ARGs, microbial community, and sediment features. Network analysis showed that interaction between ARGs and microbial community in coastal sediments was more frequent than that in marine sediment. The anthropogenic factors posed high positive effect on ARGs in marine/coastal sediments with contribution coefficient of 0.524/1.094 while bacterial community mainly posed positive effect on ARGs in marine sediments with contribution coefficient of 0.475, illustrating that spread and proliferation of land-based ARGs in marine sediments might be mainly affected by anthropogenic and microbial factors. These findings provided new information on fate and drivers of ARGs in marginal sea.

Medicines as an emergent contaminant: the review of microbial biodegration potential

Emerging environmental contaminants, such as medicine waste, are of great concern to the scientific community and to the local environmental and health departments because of their potential long-term effects and ecotoxicological risk. Besides the prolonged use of medicines for the development of modern society, the elucidation of their effect on the ecosystem is relatively recent. Medicine waste and its metabolites can, for instance, cause alterations in microbial dynamics and disturb fish behavior. Bioremediation is an efficient and eco-friendly technology that appears as a suitable alternative to conventional methods of water waste and sludge treatment and has the capacity to remove or reduce the presence of emerging contaminants. Thus, this review has the objective of compiling information on environmental contamination by common medicines and their microbial biodegradation, focusing on five therapeutic classes: analgesics, antibiotics, antidepressants, non-steroidal anti-inflammatory drugs (NSAIDs), and contraceptives. Their effects in the environment will also be analyzed, as well as the possible routes of degradation by microorganisms.

Spatial distribution and health risk assessment of dissolved heavy metals in groundwater of eastern China coastal zone

Environmental changes and human activities have deteriorated the quality of groundwater, which is an important source of freshwater in coastal areas. The Jiangsu Coastal Zone (JCZ), which is a typical area of the eastern China coastal zone (ECCZ), has a great demand for clean water resources due to its dense population. The groundwater in the JCZ is affected by both human activities and seawater intrusion. However, research on heavy metals in the groundwater of the JCZ is limited. This study investigated the spatial distribution characteristics and influencing factors of heavy metals in coastal groundwater of Jiangsu Province and conducted a health risk assessment (HRA). Relatively high concentrations of Cu, Cd, Pb, Co, Zn, and Ba existed in the northern JCZ, while As and B predominated in the central JCZ. The main heavy metal pollutants in the groundwater are B and As, with mean values at 0.61 mg/L and 0.02 mg/L, exceeding the standard rate reaching 48.28% and 18.07% respectively. The HRA results showed that B had the largest hazard quotient (HQ), accounting for 50.22% of the total HQs, and As was attributed to the pollutant with the largest cancer risk (CR), accounting for 99.74% of the total CRs. According to the results of the correlation analysis, heavy metals in the groundwater of JCZ mainly originated from industrial pollution, seawater intrusion, and mineral dissolution. Seawater intrusion increases the content of As and B in groundwater, leading to higher health risks. Therefore, the government should strengthen the supervision of seawater intrusion by implementing more effective water resource management policies, or adopting engineering measures such as installing subsurface physical barriers to prevent and control seawater intrusion.

Enhanced removal of phenolic endocrine disrupting chemicals from coastal waters by intertidal macroalgae

The phytoremediation of phenolic endocrine disrupting compounds (EDCs) in coastal waters by intertidal macroalgae was firstly investigated. The results showed that intertidal macroalgae could remove bisphenol A (BPA) and nonylphenol (NP) at environmental relevant concentration, and Ulva pertusa was the most efficient one. In most cases, the order of EDCs removal efficiency could be expressed as: green algae > brown algae > red algae. The in-situ monitoring using a charge-coupled device imaging system confirmed the accumulation of EDCs in the intertidal macroalgae. The removal mechanisms included the initial rapid biosorption process, followed by the slow accumulation and biodegradation. The removal efficiency of BPA and NP was slightly dependent on temperature and nutrient concentration. A linear relationship was observed between the initial concentration and the average removal rate (R² > 0.99). The BPA and NP at the environmental relevant concentration (100 μg L^-1) could be removed efficiently using Ulva pertusa even after three cycles in pilot-scale experiments. The high removal efficiency of NP and BPA was also confirmed by the field investigation from the intertidal zone with abundant Ulva pertusa. These findings demonstrated that intertidal macroalgae could play essential role for the phytoremediation of phenolic EDCs in coastal waters.

Recent Advances in the Rejection of Endocrine-Disrupting Compounds from Water Using Membrane and Membrane Bioreactor Technologies: A Review

Water is a critical resource necessary for life to be sustained, and its availability should be secured, appropriated, and easily obtainable. The continual detection of endocrine-disrupting chemicals (EDCs) (ng/L or µg/L) in water and wastewater has attracted critical concerns among the regulatory authorities and general public, due to its associated public health, ecological risks, and a threat to global water quality. Presently, there is a lack of stringent discharge standards regulating the emerging multiclass contaminants to obviate its possible undesirable impacts. The conventional treatment processes have reportedly ineffectual in eliminating the persistent EDCs pollutants, necessitating the researchers to develop alternative treatment methods. Occurrences of the EDCs and the attributed effects on humans and the environment are adequately reviewed. It indicated that comprehensive information on the recent advances in the rejection of EDCs via a novel membrane and membrane bioreactor (MBR) treatment techniques are still lacking. This paper critically studies and reports on recent advances in the membrane and MBR treatment methods for removing EDCs, fouling challenges, and its mitigation strategies. The removal mechanisms and the operating factors influencing the EDCs remediation were also examined. Membranes and MBR approaches have proven successful and viable to eliminate various EDCs contaminants.

Occurrence and risk assessment of steroid estrogens in environmental water samples: A five-year worldwide perspective

The ubiquitous occurrence of steroid estrogens (SEs) in the aquatic environment has raised global concern for their potential environmental impacts. This paper extensively compiled and reviewed the available occurrence data of SEs, namely estrone (E1), 17α-estradiol (17α-E2), 17β-estradiol (17β-E2), estriol (E3), and 17α-ethinyl estradiol (EE2), based on 145 published articles in different regions all over the world including 51 countries and regions during January 2015-March 2020. The data regarding SEs concentrations and estimated 17β-estradiol equivalency (EEQ) values are then compared and analyzed in different environmental matrices, including natural water body, drinking and tap water, and wastewater treatment plants (WWTPs) effluent. The detection frequencies of E1, 17β-E2, and E3 between the ranges of 53%-83% in natural water and WWTPs effluent, and the concentration of SEs varied considerably in different countries and regions. The applicability for EEQ estimation via multiplying relative effect potency (REP_i) by chemical analytical data, as well as correlation between EEQ_bio and EEQ_cal was also discussed. The risk quotient (RQ) values were on the descending order of EE2 > 17β-E2 > E1 > 17α-E2 > E3 in the great majority of investigations. Furthermore, E1, 17β-E2, and EE2 exhibited high or medium risks in water environmental samples via optimized risk quotient (RQ_f) approach at the continental-scale. This overview provides the latest insights on the global occurrence and ecological impacts of SEs and may act as a supportive tool for future SEs investigation and monitoring.

One-step green preparation of magnetic seaweed biochar/sulfidated Fe0 composite with strengthen adsorptive removal of tetrabromobisphenol A through in situ reduction

Rare information is available on the facile preparation of biochar/sulfidated Fe⁰ composite. A facile one-step green method was established for the synthesis of magnetic seaweed (Ulva prolifera) biochar/sulfidated Fe⁰ composite (S-Fe⁰/BC) to use excessive seaweed biomass. Removal efficiency of tetrabromobisphenol A (TBBPA) reached up to 88% in iron-sulfur treatment. Two major products were identified as bisphenol A and monobromobisphenol A, confirming the in-situ reductive debromination of TBBPA. Batch experiments showed that the removal of TBBPA was facilitated with S/Fe molar ratio of 0.2 and acidic conditions (pH = 3-7). The S-Fe⁰/BC composite had good stability and reusability based on the cycle experiments. The removal process of TBBPA by S-Fe⁰/BC composite might include chemical adsorption by S-Fe⁰/BC composite, reduction debromination by S-Fe⁰ and enhanced electron transfer. The environmentally-friendly S-Fe⁰/BC composite synthesized by one-step facile procedure showed novel potential applications in terms of pollution control of halogenated xenobiotic compounds such as TBBPA.