Application of FTIR two-dimensional correlation spectroscopy (2D-COS) analysis in characterizing environmental behaviors of microplastics: A systematic review.

Microplastics (MPs) are ubiquitous in the environment, continuously undergo aging processes and release toxic chemical substances. Understanding the environmental behaviors of MPs is critical to accurately evaluate their long-term ecological risk. Generalized two-dimensional correlation spectroscopy (2D-COS) is a powerful tool for MPs studies, which can dig more comprehensive information hiding in the conventional one-dimensional spectra, such as infrared (IR) and Raman spectra. The recent applications of 2D-COS in analyzing the behaviors and fates of MPs in the environment, including their aging processes, and interactions with natural organic matter (NOM) or other chemical substances, were summarized systematically. The main requirements and limitations of current approaches for exploring these processes are discussed, and the corresponding strategies to address these limitations and drawbacks are proposed as well. Finally, new trends of 2D-COS are prospected for analyzing the properties and behaviors of MPs in both natural and artificial environmental processes.

Exploring the variations in molecular characteristics of dissolved organic matter driven by aquaculture types.

In recent decades, global aquaculture has expanded rapidly, raising concerns about coastal environmental degradation due to unregulated or poorly regulated discharge of aquaculture tailwater. Despite the crucial role of dissolved organic matter (DOM) in biogeochemical processes and aquatic biodiversity, the influence of aquaculture type on the molecular characteristics of DOM remains largely unexplored. Herein, this study investigated the variations in chemical and spectroscopic properties as well as molecular characteristics and composition of DOM across different aquaculture types including crustacean, fish and shellfish. Our findings revealed notable differences in DOM quantities among different aquaculture types, with crustacean and fish aquaculture water containing higher DOM amount compared to shellfish aquaculture water. This disparity can be attributed to the more frequent formulated feeds of crustacean and fish in contrast to shellfish aquaculture. Furthermore, distinct differences were also observed in the characteristics and composition of DOM among the different aquaculture waters. Specifically, DOM in shellfish aquaculture water exhibited a higher abundance of unsaturated and reduced molecules as well as increased aromaticity compared to the other two aquaculture waters. Conversely, DOM from fish aquaculture water showed a greater contribution from terrestrial origin characterized by elevated levels of plant-based components such as lignin-like and tannin-like compounds. Interestingly, DOM from shellfish aquaculture water contained lower levels of microbial-derived components such as lipid-like and protein-like compounds, likely due to reduced microorganism populations resulting from lower nutrients availability and higher salinity. Overall, these significant variations in characteristics and composition of DOM underscore the potential impacts of aquaculture type on the DOM biogeochemical cycle and the environmental quality in aquatic ecosystems.

Application of the Biological Toxicity Effect Ratio (BER) Method for Advancing Water Quality Criteria Derivation.

Water quality criteria (WQC) serve as a scientific foundation for pollutant risk assessment and control in aquatic ecosystems. The development of regionally differentiated WQC tailored to specific regional characteristics has become an emerging trend. However, the current WQC is constrained by a lack of regional species toxicity data. To address these limitations, this study proposes the biological toxicity effect ratio (BER) method, which indirectly reflects the toxicity sensitivity of the overall aquatic ecosystem through the toxicity information on a limited number of species, enabling rapid WQC prediction. Using the established WQC in China and the USA as a case study, we combined mathematical derivation and data validation to evaluate the BER method. Among various species-taxon groups of freshwater organisms, planktonic crustaceans demonstrated the highest predictive accuracy. Our analysis further revealed that species toxicity sensitivity and regional variability jointly influence the prediction accuracy. Regardless of the evaluation indexes, planktonic crustaceans emerged as the most suitable species-taxon group for the BER method. Additionally, the BER method is particularly applicable to pollutants with conserved mechanisms across species. This study systematically explores the feasibility of using the BER method and offers new insights for deriving regionally differentiated WQC.

[Analysis of Regional Differences in Cadmium Ecological Risk in Surface Waters of the Yangtze River Basin].

This study primarily focused on the regional disparities in both water quality criteria and ecological risks attributed to cadmium presence within the surface waters of the Yangtze River Basin. In the initial phase, the long-term water quality criteria for cadmium were recalibrated in accordance with the guidelines outlined in China's "Water Quality Criteria for Freshwater Aquatic Organisms-Cadmium," accounting for the prevalent hardness distribution within the Yangtze River Basin's surface water. Subsequently, a more refined revision was undertaken considering the specific characteristics of the species residing within the Yangtze River Basin. This undertaking led to a comprehensive interpretation of the regional variations in both the distribution of long-term water quality criteria values and the risk quotient distribution of cadmium throughout the Yangtze River Basin. The incorporation of hardness and species-specific attributes resulted in a revised range of long-term water quality criteria for cadmium across different urban locales within the Yangtze River Basin. Notably, the recalibrated values ranged from 0.08 µg·L-1 as the lowest threshold to 0.75 µg·L-1 as the upper limit, signifying a tenfold differentiation. Correspondingly, the urban average annual risk quotient associated with cadmium exposure demonstrated a variation from 0.035 to 1.12, marking a significant 32-fold discrepancy between the lowest and highest values. It is essential to highlight that regions of paramount importance, such as the confluence area connecting the upper and middle stretches of the Yangtze River Basin and the intricate Dongting Lake system, exhibited noteworthy ecological risks attributed to cadmium presence. Consequently, further in-depth investigations into these critical regions are imperative for a comprehensive understanding of the associated risks.

Releasing characteristics of toxic chemicals from polystyrene microplastics in the aqueous environment during photoaging process.

Microplastics (MPs) are pervasive in the environment and inevitably undergo photoaging due to UV irradiation. This study delved into the dynamic releasing and transformation process of toxic chemicals from polystyrene microplastics (PS MPs) during photoaging, a subject that remains underexplored. It was revealed that photoaging led to substantial alterations in the physicochemical properties of PS MPs, initiating polymer chain scission and facilitating the release of a large number of toxic chemicals, including numerous organic compounds and several inorganic compounds. The kinetic analysis revealed a dynamic release pattern for PS MPs, where under varying UV intensities (2, 5, and 10 mW/cm2), the release rate (kDOC) initially increased and then decreased, peaking at a total irradiation energy of approximately 7 kW·h/m2. Furthermore, chemicals in leachate were transformed into compounds with smaller molecular weight, higher oxidized and greater unsaturated state over the prolonged photoaging. This transformation was primarily attributed to two reasons. Firstly, the aged PS MPs released chemicals with higher oxidized state compared to the pristine MPs. Secondly, the chemicals previously released underwent further reactions. Besides, among the complex leachate generated by aged PS MPs, the organic chemicals characterized by small molecular weight and high oxidized state exhibited notable acute toxicity, whereas heavy metal ions showed lesser toxicity, and anions were non-toxic. This study shed more light on the photoaging process of PS MPs, releasing characteristics of organic chemicals, and the potential environmental risks associated with plastic wastes.

Formation of nitrogen-containing disinfection by-products during the chloramination treatment of an emerging pollutant.

Chloramination was commonly used as disinfectant for killing pathogens in water. However, in this process, nitrogen-containing disinfection by-products (N-DBPs) would accidently form and subsequently rise toxicity. Here, we investigated acute toxicity variation and by-products formation during chloramination treatment on UV filter 2-hydroxy-4-methoxy-5-sulfonic acid benzophenone (BP-4). Under alkaline conditions, the acute toxicity of this system had significant increase. A total of 17 transformation products were tentatively identified, and for them, plausible transformation pathways were proposed. Noticeably, numerous aniline and nitrosobenzene analogs were detected, and the dramatic increase of acute toxicity in this system might be primarily attributed to the formation of benzoquinone and aniline analogs. Besides, bromophenol, iodophenol and iodobenzoquinone analogs exhibiting high toxicity were generated in the presence of bromine and iodide ions. This study indicates that chloramination treatment may significantly increase potential health risk, further management on disinfection system is reasonable.

Profound regional disparities shaping the ecological risk in surface waters: A case study on cadmium across China.

The scientific advancement of water quality criteria (WQC) stands as one of the paramount challenges in ensuring the security of aquatic ecosystem. The region-dependent species distribution and water quality characteristics would impact the toxicity of pollutant, which would further affect the derivation of WQC across regions. Presently, however, numerous countries adhere to singular WQC values. The "One-size-fits-all" WQC value for a given pollutant may lead to either "over-protection" or "under-protection" of organisms in specific region. In this study, we used cadmium(Cd) pollution in surface waters of China as a case study to shed light on this issue. This study evaluated critical water quality parameters and species distribution characteristics to modify WQC for Cd across distinct regions, thus unveiling the geographical variations in ecological risk for Cd throughout China. Notably, regional disparities in ecological risk emerged a substantial correlation with water hardness, while species-related distinctions magnified these regional variations. After considering the aforementioned factors, the variation in long-term WQC among different areas reached 84-fold, while the divergence in risk quotient extended to 280-fold. This study delineated zones of both heightened and diminished ecological susceptibility of Cd, thereby establishing a foundation for regionally differentiated management strategies.

Advancements in Additive Manufacturing of Tantalum via the Laser Powder Bed Fusion (PBF-LB/M): A Comprehensive Review.

Additive manufacturing (AM) exhibits a prime increment in manufacturing technology development. The last few decades have witnessed massive improvement in this field of research, including the growth in the process, equipment, and materials. Irrespective of compelling technological advancements, technical challenges provoke the application and development of these technologies. Metal additive manufacturing is considered a prime sector of the industrial revolution. Various metal AM techniques, including Selective Laser Sintering (SLS), Laser Powder Bed Fusion (PBF-LB/M), and Electron Beam Powder Bed Fusion (PBF-EB/M), have been developed according to materials and process classifications. PBF-LB/M is considered one of the most suitable choices for metallic materials. PBF-LB/M of tantalum has become a hot topic of research in the current century owing to the high biocompatibility of tantalum and its high-end safety applications. PBF-LB/M of porous Ta can direct unexplored research prospects in biomedical and orthopedics by adapting mechanical and biomedical properties and pioneering implant designs with predictable features. This review primarily examines the current advancements in the additive manufacturing of tantalum and related alloys using the PBF-LB/M process. The analysis encompasses the evaluation of process parameters, mechanical properties, and potential biological applications. This will offer the reader valuable insights into the present state of PBF-LB/M for tantalum alloys.

Magnitude Filter Combined with Mass Filter: A Reliable Strategy to Improve the Reproducibility of ESI-FT-ICR-MS Analysis on the Fingerprint of Dissolved Organic Matter.

Dissolved organic matter (DOM) has been used frequently to distinguish different environmental samples based on its abundant fingerprint information. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) is the most powerful technique to analyze the complex composition of DOM. Balancing between the reproducibility of peak magnitude and peak diversity is a key factor for achieving reliable and reproducible fingerprint information of DOM with FT-ICR-MS. In this paper, a novel magnitude filter (MGF) method and a novel MS-MGF strategy were proposed to improve the data reproducibility of FT-ICR-MS analysis. With the MS-MGF strategy, a 20% magnitude filter threshold (TMGF) was recommended to remove magnitude outliers, and a relatively low signal-to-noise ratio (SNR) threshold of 3.5 was recommended to retain those low but stable-magnitude peaks. The total relative magnitude was recommended since it could obtain better reproducibility of MS analysis compared to other types of peak magnitude. In addition, three replicates were enough to obtain satisfactory reproducibility. More importantly, the proposed MS-MGF strategy was also adaptable to different FT-ICR-MS instruments and different experimental conditions. Overall, the results are expected to initiate the promising applications of the MS-MGF strategy to distinguish the reliable fingerprint characteristics of DOM samples from different sources.

[Evaluation Parameters and System for Reclaimed Water Quality Stability].

Wastewater reclamation and reuse are an effective measure to alleviate water shortages. Water quality stability is the premise for safe utilization of reclaimed water and other water resources. Stable water quality can prevent the frequent occurrence of corrosion and scaling, which not only improves the sensory properties of water quality but also reduces secondary pollution and energy consumption. In order to promote the utilization of wastewater resources, it is important to evaluate and manage reclaimed water quality stability. Based on substantial literature and research, the characteristics and scopes of evaluation parameters for both chemical stability and biological stability were summarized, and a set of evaluation parameters and a system for reclaimed water quality stability were comprehensively established in this study. The evaluation procedure was mainly divided into four steps including:① determine the influencing factors of reclaimed water quality stability; ② select corresponding evaluation parameters based on reclaimed water quality characteristics, the materials of pipelines, and equipment; ③ evaluate the reclaimed water quality stability; and ④ examine whether the evaluation results were appropriate. Finally, the potential challenges for the stability evaluation of water quality were analyzed. This study is expected to provide a theoretical foundation for the scientific evaluation of water quality stability and safe utilization of reclaimed water.

A synthetical methodology for identifying priority pollutants in reclaimed water based on meta-analysis.

Wastewater reclamation and reuse is an increasing global project, while the reclamation treatment on wastewater does not completely remove all pollutants in water. The residual pollutants in reclaimed water would cause potential risk on human health and ecosystem safety during the long-term use. It is impossible to analyze and control all pollutants one by one in practice, therefore, identification and control of priority pollutants will be efficient strategy to ensure the safe use of reclaimed water. An integrated three-step methodology for identifying priority pollutants in reclaimed water was proposed in this study. First, a comprehensive literature survey on the occurrence of pollutants in reclaimed water was conducted, and a dataset DPR for pollutants occurrence in reclaimed water was established, containing 1,113 pollutants. Second, 611 chemicals that had been recommended as hazardous pollutants for various water bodies in previous literatures were summarized, and a dataset DHP for hazardous pollutants in water was obtained. Third, meta-analysis on these two datasets (DPR and DHP) was performed, a new dataset DHPR for hazardous pollutants in reclaimed water was established, including 265 candidates. Finally, 59 substances out of dataset DHPR were identified as priority pollutants for reclaimed water based on their recommendation frequency. It is expected that this synthetical methodology will provide powerful support for scientific evaluating and managing water pollution and ensuring safe use of reclaimed water.

A novel risk score-based prioritization method for pollutants in reclaimed water.

Wastewater reclamation and reuse is a sustainable solution for alleviating the scarcity of water resources. However, the potential risks resulting from the residual pollutants in reclaimed water are of concern. Identifying of priority pollutants would be a practical approach for the management and scientific evaluation of risks associated with reclaimed water reuse. In this study, a novel risk score-based method is proposed for prioritizing residual pollutants in reclaimed water. First, target the specific applications and possible scenarios of reclaimed water as well as recognize the potential receptors and exposure pathways. Second, determine exposure and effect parameters, and assign values to every parameter. Third, calculate the total exposure score and effect score for each pollutant using a weighted method, then calculate the risk score by multiplying total exposure score and effect score, and rank all pollutants based on their risk scores from high to low. Fourth, recommend a priority pollutants list for reclaimed water reuse. To demonstrate the procedure and validate the method, a case study on groundwater recharge with reclaimed water was conducted. In the case study, EE2 and E2, which have also been listed in other recent water quality standards, were identified as priority pollutants. The case study illustrated sufficient reliability, great discrimination and feasibility of the method. The five exposure parameters and seven effect parameters in this method can objectively evaluate the potential risk of pollutants and identify priority pollutants for the specific application of reclaimed water. This application-oriented and risk-based prioritization method is easy to understand and simple to operate in practice. This study fills existing gaps by proffering a novel prioritization method to identify priority pollutants in reclaimed water for an accurate evaluation and safety management of recycled wastewater.

[Key Problems and Novel Strategy of Controlling Emerging Trace Organic Contaminants During Municipal Wastewater Reclamation].

Emerging trace organic contaminants (TOrCs) have been ubiquitously detected in municipal wastewater. TOrCs show low concentrations but are usually harmful to aquatic biota and recalcitrant to treatments. The advanced treatment of TOrCs is challenged by four main aspects. First, it is hard to qualify the chemical structure and concentrations of TOrCs, which are typically very low. Second, risk assessment results vary with the selection of target-species and toxicity-endpoints, which makes it hard to regulate priority lists and concentration limits. Third, TOrCs account for less than 0.01% of the total organics in wastewater. Thus, TOrCs cannot be selectively and efficiently removed by conventional treatments. Fourth, it is hard to optimize and manage the treatment trains of TOrCs. In this manuscript, a new strategy combing non-targeting TOrC screening and TOrC "fingerprinting" are proposed to overcome the difficulties of quantification and treatment optimization. Based on this, the standards and regulations to control the TOrCs in reclaimed water should be developed on the basis of elimination efficiency rather than concentration.

Bioassay- and QSAR-based screening of toxic transformation products and their formation under chlorination treatment on levofloxacin.

Levofloxacin (LEV) is a broad-spectrum quinolone antibiotic and widely used for human and veterinary treatment. Overuse of LEV leads to its frequent occurrence in the water environment. In this study, the transformation characteristics of LEV in water during the simulated chlorination disinfection treatment were explored. Fifteen major transformation products (TPs) of LEV were identified, and their plausible formation pathways were proposed. The reaction pathways were strongly dependent on pH condition, and LEV removal was relevant to free available chlorine (FAC) dose. Antibacterial activity of chlorination system was dramatically declined when FAC was more than 3-equivalent (eq) due to the elimination of antibacterial related functional groups. Genotoxicity of chlorination system increased more than 3 times at 0.5-eq of FAC and then decreased with increasing FAC dose, which were in accordance with the relative concentration of toxic TPs estimated by QSAR model. These results implied that the combination of bioassay, QSAR computation and chemical analysis would be an efficient method to screen toxic TPs under chlorination treatment. It is anticipated that the results of this study can provide reference for optimizing operational parameters for water disinfection treatment, and for scientifically evaluating the potential risk of quinolone antibiotics.

Characterization of UV and chlorine contributions to transformation of 2,3,4-trihydroxybenzophenone under combined UV-chlorine treatment.

Combined UV-chlorine treatment is a promising disinfection technology providing synergistic effects on bacteria-killing. The interaction between UV and chlorine would affect pollutants removal and disinfection by-products formation, while little is known about how UV and chlorine respectively contribute to pollutants transformation under combined UV-chlorine treatment. In this study, UV filter 2,3,4-trihydroxybenzophenone (2,3,4-THBP) was selected as a model compound to investigate the transformation characteristics and acute toxicity variation under combined UV-chlorine treatment. Especially, separative UV and chlorination treatments were conducted to illustrate their respective contribution in combined UV-chlorine treatment. It was found that the optimal removal percentage of 2,3,4-THBP under combined UV-chlorine treatment was 85.3% within 5 min and kept stable until 3 h at 3-equivalent (equiv.) of free available chlorine (FAC) and 1 mW/cm2 of irradiation intensity. Correspondingly, acute toxicity of reaction mixture at 3 h increased twice as high as that of 2,3,4-THBP itself. Four transformation products were tentatively identified, and their formation possibly involved the reactions of chlorine substitution, oxidation, hydroxylation, and hydrolysis. FAC initiated the preliminary transformation of 2,3,4-THBP, and the synergistic effects of UV and chlorine promoted the further transformation of intermediates from chlorination treatment. Most important was that, 2,3,4-THBP could form some toxic products in the real ambient water matrix under solar irradiation, and acute toxicity of reaction mixture was 1.84 times higher than that of 2,3,4-THBP. This study would provide a better understanding on the transformation characteristics of pollutants under combined UV-chlorine treatment, and provide a reference for optimizing disinfection treatment.

Free available chlorine initiated Baeyer-Villiger oxidation: A key mechanism for chloroform formation during aqueous chlorination of benzophenone UV filters.

Chloroform, a regulated disinfection by-product in water, is often generated during chlorination disinfection treatment. However, the formation of chloroform is heavily dependent on the molecular structures of precursors. Moreover, compounds containing ketone moiety are ubiquitous in water environments. However, it is unclear if they can generate chloroform during chlorination. In this study, 14 benzophenones (BPs), efficient and widely used UV filters, with different substituents were selected to explore chloroform formation during chlorination. All 14 BPs generated chloroform, with yields dependent on their molecular structures and operational conditions. Compounds 2,2',4,4'-tetrahydroxy-BP and benzophenone produced the highest and lowest chloroform of 0.313 and 0.013 g/g, respectively, corresponding to the fastest and slowest formation rate constants of 1.41 × 10-1 and 2.71 × 10-2 min-1. Alkaline conditions and high chlorine dosages were favorable to chloroform formation. Three reactions played key roles in chloroform formation from BPs: (1) chlorine initiated Baeyer-Villiger oxidation converted ketone moieties of BP molecules into esters; (2) the esters further underwent hydrolysis and formed phenolic and benzoic products; and (3) benzoic acids underwent decarboxylation and hydrolysis to form phenolic products. Subsequently, these phenolic products could further generate chloroform in the chlorination system. More importantly, BPs could generate chloroform in the ambient water matrices during practical chlorination treatment. This work emphasized the critical role of Baeyer-Villiger oxidation for chloroform formation, implying that pollutants containing aromatic ketone moieties generate chloroform during chlorination disinfection, and their potential risk should therefore be reviewed.

The origin and spread of CRF85_BC, driven by heterosexual transmission among older people in Sichuan, China.

BACKGROUND: CRF_BC recombinants, including CRF07_BC and CRF08_BC, were considered the predominant subtypes in China. Since the discovery of HIV-1 circulating recombinant form CRF 85_BC in Southwest China in 2016, this BC recombinant forms had been reported in different regions of China. However, the history and magnitude of CRF85_BC transmission were still to be investigated. METHOD: We conducted the most recent molecular epidemiology of HIV-1 among newly reported HIV-1 infected patients in Sichuan in 2019 by sequencing and phylogenetic analysis of 1291 pol sequences. Then, we used maximum likelihood approach and the Bayesian Markov chain Monte Carlo (MCMC) sampling of pol sequences to reconstruct the phylogeographic and demographic dynamics of the CRF85_BC. RESULTS: HIV-1 CRF85_BC (68/1291, 5.27%) became the fourth most prevalent strain revealing a significant increase in local population. CRF85_BC were only found in heterosexually infected individuals and the majority of CRF85_BC (95.45%) were circulating among the people living with HIV aged 50 years and over (PLHIV50+), suggesting a unique prevalent pattern. The founder lineages of CRF85_BC were likely to have first emerged in Yunnan, a province of Southwest China bordering Sichuan, in the early 2000s. It then spread exponentially to various places (including Guangxi, Sichuan, et al) and became endemic around 2008.6 (2006.7-2010.2) in Sichuan. CONCLUSION: Taken together, our findings on HIV-1 subtype CRF85_BC infections provided new insights into the spread of this virus and extended the understanding of the HIV epidemic in China.

A selective N,N-dithenoyl-rhodamine based fluorescent probe for Fe3+ detection in aqueous and living cells.

A novel N,N-dithenoyl-rhodamine based fluorescent and colorimetric Fe3+ probe 1 was designed and synthesized by only one step from Rhodamine B hydrazide and 2-thiophenecarbonyl chloride. The structure of probe 1 was characterized by 1H NMR/13C NMR spectroscopy, IR spectroscopy, and HRMS spectrometry. Accompanying with significant changes in visual color and fluorescent spectrum, probe 1 displayed good sensitivity for Fe3+ with an abroad pH span. The detection limit (3.76 µmol/L, 0.2 mg/L) for Fe3+ was lower than WHO recommended value (0.3 mg/L) for drinking water. Using two thiophene carbonyl groups as coordinating functional recognition group, probe 1 showed excellent selectivity towards Fe3+ over diverse coexistent metal ions and anions. The sensing mechanism between dithenoyl-substituted probe 1 and Fe3+ was further confirmed by 1H NMR and IR titration experiments, binding constants study, and Job's plot analysis. Furthermore, probe 1 also exhibited good cell membrane permeability and could be used as an efficient Fe3+ probe in living human cells.

Bioassay: A useful tool for evaluating reclaimed water safety.

Wastewater reclamation and reuse has been proved to be an effective way to relieve the fresh water crisis. However, toxic contaminants remaining in reclaimed water could lead to potential risk for reuse, and the conventional water quality standards have difficulty guaranteeing the safety of reclaimed water. Bioassays can vividly reflect the integrated biological effects of multiple toxic substances in water as a whole, and could be a powerful tool for evaluating the safety of reclaimed water. Therefore, in this study, the advantages and disadvantages of using bioassays for evaluating the safety of reclaimed water were compared with those of conventional water quality standards. Although bioassays have been widely used to describe the toxic effects of reclaimed water and treatment efficiency of reclamation techniques, a single bioassay cannot reflect the complex toxicity of reclaimed water, and a battery of bioassays involving multiple biological effects or in vitro tests with specific toxicity mechanisms would be recommended. Furthermore, in order to evaluate the safety of reclaimed water based on bioassay results, various methods including potential toxicology, the toxicity unit classification system, and a potential eco-toxic effects probe are summarized as well. Especially, some integrated ranking methods based on a bioassay battery involving multiple toxicity effects are recommended as useful tools for evaluating the safety of reclaimed water, which will benefit the promotion and guarantee the rapid development of the reclamation and reuse of wastewater.

Predicted no-effect concentrations determination and ecological risk assessment for benzophenone-type UV filters in aquatic environment.

Benzophenones (BPs), a group of widely used ultraviolet filters, have been frequently detected out in multiple environment matrices even in organism bodies. Although a variety of toxicological effects of BPs have been disclosed recently, it is barely to evaluate the potential ecological risk of BPs due to lack of reference criteria. Therefore, the determination of predicted no-effect concentration (PNEC) values is necessary for assessing ecological risk of BPs and for protecting safety of aquatic organisms. The toxicological data of 14 BPs from both in vivo tests on aquatic organisms and in vitro tests on strains/cell lines were collected from previous reports, and two methods including assessment factor (AF) and species sensitivity distribution (SSD) were applied to calculate PNECs, respectively. Four groups of PNECs were obtained and compared, a final PNEC value was recommended for each BP based on reliable and conservative consideration. With these PNECs values, the risk quotients of 8 BPs from 35 ambient freshwater samples were calculated, the results demonstrated that 3 BPs including 2,2',4,4'-tetrahydroxyl-BP, 2-hydroxyl-4-methoxyl- BP, and 2-hydroxyl-4-methoxyl-5-sulfonic acid-BP exhibited high ecological risk, and the ecological risk posed by BPs in River Tiff in UK was great. It is anticipated that these results would provide useful reference for assessing and managing BP-type compounds, and for selecting toxicity data and methods to derive PNECs for emerging contaminants.