Comparative evaluation of SPE methods for biotoxicity assessment of water and wastewater: Linkage between chemical extracting efficiency and biotoxicity outcome.

Biotoxicity assessment results of environmental waters largely depend on the sample extraction protocols that enrich pollutants to meet the effect-trigger thresholds of bioassays. However, more chemical mixture does not necessarily translate to higher combined biotoxicity. Thus, there is a need to establish the link between chemical extracting efficiency and biotoxicity outcome to standardize extraction methods for biotoxicity assessment of environmental waters. This study compares the performance of five different extraction phases in solid phase extraction (SPE), namely HLB, HLB+Coconut, C18 cartridge, C18 disk and Strata-X, and evaluated their chemical extracting efficiencies and biotoxicity outcomes. We quantitatively assessed cytotoxicity, acute toxicity, genotoxicity, estrogenic activity, and neurotoxicity of the extracts using in vitro bioassays and characterized the chemical extracting efficiencies of the SPE methods through chemical recoveries of 23 model compounds with different polarities and total organic carbon. Using Pareto ranking, we identified HLB+Coconut as the optimal SPE method, which exhibited the highest level of water sample biotoxicity and recovered the most chemicals in water samples. We found that the biotoxicity outcomes of the extracted water samples significantly and positively correlated with the chemical extracting efficiencies of the SPE methods. Moreover, we observed synchronous changing patterns in biotoxicity outcome and chemical extracting efficiencies in response to increasing sample volumes per cartridge (SVPC) during SPE. Our findings underscore that higher chemical extracting efficiency of SPE corresponds to higher biotoxicity outcome of environmental water samples, providing a scientific basis for standardization of SPE methods for adequate assessment of biotoxicities of environmental waters.

Scientometric analysis of electrocatalysis in wastewater treatment: today and tomorrow.

Electrocatalytic methods are valuable tools for addressing water pollution and scarcity, offering effective pollutant removal and resource recovery. To investigate the current status and future trends of electrocatalysis in wastewater treatment, a detailed analysis of 9417 papers and 4061 patents was conducted using scientometric methods. China emerged as the leading contributor to publications, and collaborations between China and the USA have emerged as the most frequent partnerships. Primary article co-citation clusters focused on oxygen evolution reaction and electrochemical oxidation, transitioning towards advanced oxidation processes ("persulfate activation"), and electrocatalytic reduction processes ("nitrate reduction"). Bifunctional catalysts, theoretical calculations, electrocatalytic combination technologies, and emerging contaminants were identified as current research hotspots. Patent analysis revealed seven types of electrochemical technologies, which were compared using SWOT analysis, highlighting electrochemical oxidation as prominent. The technological evolution presented the pathway of electro-Fenton to combined electrocatalytic technologies with biochemical processes, and finally to coupling with electrocoagulation. Standardized evaluation systems, waste resource utilization, and energy conservation were important directions of innovation in electrocatalytic technologies. Overall, this study provided a reference for researchers to understand the framework of electrocatalysis in wastewater treatment and also shed light on potential avenues for further innovation in the field.

Correlations between China's socioeconomic status, disease burdens, and pharmaceuticals and personal care product levels in wastewater.

The presence of pharmaceutical and personal care products (PPCPs) in domestic wastewater can potentially indicate socioeconomic status and disease burdens. However, current knowledge is limited to the correlation between specific pharmaceuticals and diseases. This study aims to explore the associations between socioeconomic status, disease burdens, and PPCP levels in domestic wastewater at a national level. Samples from 171 wastewater influents across China were used to measure PPCPs, and the per capita consumption of PPCPs was calculated. Results showed that the 31 targeted PPCPs were widely present in wastewater with varying occurrence characteristics. The mean consumption levels of different PPCPs varied greatly, ranging from 0.03 to 110723.15 µg/d/capita. While there were no significant regional differences in the overall pattern of PPCP consumption, 22 PPCPs showed regional variations between Northern China and Southern China. PPCPs with similar usage purposes exhibited similar distribution patterns. Disease burden (70.1%) was the main factor affecting most PPCP consumption compared to socioeconomic factors (26.4%). Through correlation analyses, specific types of PPCPs were identified that were highly associated with socioeconomic status and disease burdens, such as hypertension-bezafibrate, brucellosis-quinolones, sulfonamides, hepatitis-triclosan, triclocarban, socioeconomic development-fluoxetine, and people's living standards-gemfibrozil. Despite some uncertainties, this study provides valuable insights into the relationship between PPCPs in domestic wastewater and socioeconomic status and human health.

PBT assessment of chemicals detected in effluent of wastewater treatment plants by suspected screening analysis.

Wastewater treatment plants (WWTPs) are the major sources of contaminants discharged into downstream water bodies. Profiling the contaminants in effluent of WWTPs is crucial to assess the potential eco-risks toward downstream organisms. To this end, this study investigated the contaminants in effluent of 10 WWTPs locating in 10 cities of Yangtze River delta region of China by suspected screening analysis. Further, the persistence, bioaccumulation, toxicity (PBT) and the characteristics sub-structures of PBT-like chemicals were analyzed. Totally, 704 chemicals including 155 chemical products, 31 food additives, 52 natural substances, 112 personal care products, 123 pesticides, 192 pharmaceuticals, 17 hormones and 22 others were found. The results of PBT analysis suggested that 42 chemicals (5.97% among the detected chemicals in WWTPs) were with PBT property. Among them, 31 contaminants were not reported previously. 9 characteristics sub-structures (N-methyleneisobutylamine, 1-naphthaldehyde, 2,3,3-trimethylcyclohexene, cyclohexanol, N-sec-butyl-n-propylamine, (5E)-2,6-dimethylocta-1,5-diene, 2-ethylphenol, pentadecane and 6-methoxyhexane) were found for PBT-like chemicals. The sub-structures of highly linear alkyl partially explained the significantly higher PBT score for personal care products. Present study provides fundamental information on PBT properties of contaminants in effluent of WWTPs, which will benefit to prioritize contaminants with high concerns in effluent of WWTPs.

Seasonal disparities and source tracking of airborne antibiotic resistance genes in Handan, China.

The transmission of airborne antibiotic resistance genes (ARGs) loaded on particle is a significant global public health concern. Up to date, the dispersal pattern of airborne ARGs remains unclear despite their critical role in multiregional transmission. In this study, airborne ARGs loaded on fine particulate matter (PM2.5) and source tracking based on the airflow trajectories were performed by the potential source contribution function (PSCF) and concentration weighted trajectory (CWT) model. The results show that the absolute abundance of ARG subtypes were generally twice times higher in the winter season than that in the summer season, which could be attributable to winter haze events with high particulate matter concentrations in Handan. Exogenous input from serious haze events and local release of ARGs loaded on PM2.5 of air masses may cause higher levels of ARGs in the winter. Moreover, based on the positive correlation between the abundance of ARGs and PM2.5 concentration, a source tracing model of airborne ARGs was proposed to the estimate of ARGs release and dissemination. This study highlights airborne ARGs transmission loaded on PM2.5 of air masses, which facilitating the global spread of antibiotic resistance.

Comprehensive insights into the key components of bacterial assemblages in pharmaceutical wastewater treatment plants.

Due to complexity and variety of pharmaceutical wastewater composition, little is known as for functionally important microflora of pharmaceutical wastewater treatment plants (pWWTPs). We compared bacterial composition and diversity of pWWTPs (27 sludge samples collected from 12 full-scale pWWTPs) with those of other industrial (iWWTPs) (27 samples) and municipal wastewater treatment plants (mWWTPs) (27 samples) through meta-analysis based on 16S rRNA gene amplicon sequencing, and identified putatively important organisms and their ecological correlations. Non-metric multidimensional scaling indicated that the pWWTPs, iWWTPs and mWWTPs showed distinctive differences in bacterial community composition (P < 1e-04), and the pWWTPs had significantly lower bacterial diversity than the mWWTPs (P < 1e-06). Thermotogae and Synergistetes phyla only strictly dominated in the pWWTPs, and 26, 30 and 6 specific genera were identified in the pWWTPs, mWWTPs and iWWTPs, respectively. Totally, 15 and 1300 OTUs were identified as core and occasional groups, representing 23.2% and 66.2% of the total read abundance of the pWWTPs, respectively. Permutational multivariate analysis of variance revealed that the bacterial components were clearly clustered corresponding to the types of pharmaceutical wastewater, and a total of 129 local specific OTUs were identified in the pWWTPs, among which anticancer antibiotics pWWTPs had the highest number of specific OTUs (40 ones). Co-occurrence network revealed that the species dominating in the same type of pWWTPs tended to co-occur much more frequently than theoretical random expectation. The results may extend our knowledge regarding the ecological status and correlation of the key microflora in pWWTPs.

Distribution of endotoxins in full scale pharmaceutical wastewater treatment plants and its relationship with microbial community structure.

Endotoxins are potential toxics impacting human health through respiration derived in wastewater treatment plants (WWTPs), yet the formation of endotoxins during wastewater treatment processes is still lacking research. In our study, the distribution of endotoxins and bacterial community structure in the wastewater of three full scale pharmaceutical WWTPs were explored using the limulus amebocyte lysate (LAL) test and MiSeq technique. Results showed that higher endotoxin activities in the influent of Plant A and Plant C (560 and 1140 EU/mL), stemming from the fermentation process, were found compared to that of Plant B (135 EU/mL), coming from the process of chemical synthesis. During the anaerobic treatment and the cyclic activated sludge system (CASS) in the three WWTPs, the endotoxin activity increased, while it declined in the aerobic treatment system. In all bioreactors, the relative abundance of Gram-negative bacteria accounted for 50.0-94.6%. Bacteria with high lipopolysaccharide (LPS) in LAL assay were found at the genus level of Bacteroides, Enterococcus, Desulfovibrio, and Megasphaera.

Health risk assessment of reclaimed wastewater: A case study of a conventional water reclamation plant in Nanjing, China.

Contaminated reclaimed wastewater has the potential to induce adverse effects on the health of wastewater workers and residents. However, few studies have focused on these health risks. In this study, we assessed the health risk of samples collected from different treatment processing units used in a typical water reclamation plant in Nanjing, China. Chemical analysis revealed that 40 semi-volatile organic compounds (SVOCs) and 6 N-nitrosamines (NAs) persisted after wastewater treatment. A health risk assessment revealed that the SVOCs in effluents pose negligible non-carcinogenic risk to wastewater workers and local residents as both the hazard quotient (HQ) and hazard index (HI) were all below 1.00. However, polycyclic aromatic hydrocarbons (PAHs), phthalate esters (PAEs) and NAs may present a carcinogenic risk, since their risk index via dermal exposure exceeded the safety limit (1.00×106), indicating that conventional treatment processes cannot effectively reduce the health risk in reclaimed wastewater. These results strongly suggest the need for the introduction of advanced treatment technologies capable of effectively removing SVOCs and NAs in water reclamation plants.

A novel treatment processes of struvite with pretreated magnesite as a source of low-cost magnesium.

By crystallization process, phosphorus can be recycled from wastewater. However, the reagent cost limits the application of struvite precipitation. Magnesite, as a low-cost magnesium source, can result in a cost savings, while the poor dissolution offset of low-cost reagent. In this study, most of the pyrolysate of magnesite was dissolved by changing the process of reagent addition; the solubility of the pyrolysate was increased at acid wastewater. The removal rate of phosphate by the pyrolysate was higher than that of magnesite, the phosphate removal rate was from 70.2 to 88.2% at 600 °C, 0.5 h to 1200 °C, 3 h. Phosphate removal rate was achieved optimal when calcination temperature was 700 °C at 2 h. By adding the pyrolysate to acid wastewater (pH ≤ 2) before NH4Cl, phosphate removal rate was closed to that of MgCl2 as magnesium source, while magnesite was priced at similar levels to lime.

Engineering application of anaerobic ammonium oxidation process in wastewater treatment.

Anaerobic ammonium oxidation (Anammox), a promising biological nitrogen removal process, has been verified as an efficient, sustainable and cost-effective alternative to conventional nitrification and denitrification processes. To date, more than 110 full-scale anammox plants have been installed and are in operation, treating industrial NH4+-rich wastewater worldwide, and anammox-based technologies are flourishing. This review the current state of the art for engineering applications of the anammox process, including various anammox-based technologies, reactor selection and attempts to apply it at different wastewater plants. Process control and implementation for stable performance are discussed as well as some remaining issues concerning engineering application are exposed, including the start-up period, process disturbances, greenhouse gas emissions and especially mainstream anammox applications. Finally, further development of the anammox engineering application is proposed in this review.

High Levels of Antibiotic Resistance Genes and Their Correlations with Bacterial Community and Mobile Genetic Elements in Pharmaceutical Wastewater Treatment Bioreactors.

To understand the diversity and abundance of antibiotic resistance genes (ARGs) in pharmaceutical wastewater treatment bioreactors, the ARGs in sludge from two full-scale pharmaceutical wastewater treatment plants (PWWTPs) were investigated and compared with sludge samples from three sewage treatment plants (STPs) using metagenomic approach. The results showed that the ARG abundances in PWWTP sludge ranged from 54.7 to 585.0 ppm, which were higher than those in STP sludge (27.2 to 86.4 ppm). Moreover, the diversity of ARGs in PWWTP aerobic sludge (153 subtypes) was higher than that in STP aerobic sludge (118 subtypes). In addition, it was found that the profiles of ARGs in PWWTP aerobic sludge were similar to those in STP aerobic sludge but different from those in PWWTP anaerobic sludge, suggesting that dissolve oxygen (DO) could be one of the important factors affecting the profiles of ARGs. In PWWTP aerobic sludge, aminoglycoside, sulfonamide and multidrug resistance genes were frequently detected. While, tetracycline, macrolide-lincosamide-streptogramin and polypeptide resistance genes were abundantly present in PWWTP anaerobic sludge. Furthermore, we investigated the microbial community and the correlation between microbial community and ARGs in PWWTP sludge. And, significant correlations between ARG types and seven bacterial genera were found. In addition, the mobile genetic elements (MGEs) were also examined and correlations between the ARGs and MGEs in PWWTP sludge were observed. Collectively, our results suggested that the microbial community and MGEs, which could be affected by DO, might be the main factors shaping the profiles of ARGs in PWWTP sludge.

Assessment the toxic effects of dimethoate to rotifer using swimming behavior.

The toxic effects of the common organophosphorus pesticide dimethoate on freshwater zooplankton Brachionus calyciflorus (rotifer) were tested. Because of the advantages of behavioral response in environmental monitoring, swimming behavior was used as the endpoint in this research. After exposure 6 h at five dimethoate concentrations (0.18, 0.53, 0.88, 1.23 and 1.59 mg·L(-1)), the pesticide disrupted the balance in rotifer swimming direction and caused an obvious direction preference. It also inhibited significantly the swimming angular and linear speed. Our results showed that dimethoate has a sublethal toxic effect on this aquatic invertebrate.

Modeling assessment for ammonium nitrogen recovery from wastewater by chemical precipitation.

Chemical precipitation to form magnesium ammonium phosphate (MAP) is an effective technology for recovering ammonium nitrogen (NH4(+)-N). In the present research, we investigated the thermodynamic modeling of the PHREEQC program for NH4(+)-N recovery to evaluate the effect of reaction factors on MAP precipitation. The case study of NH4(+)-N recovery from coking wastewater was conducted to provide a comparison. Response surface methodology (RSM) was applied to assist in understanding the relative significance of reaction factors and the interactive effects of solution conditions. Thermodynamic modeling indicated that the saturation index (SI) of MAP followed a polynomial function of pH. The SI of MAP increased logarithmically with the Mg2+/NH4+ molar ratio (Mg/N) and the initial NH4(+)-N concentration (CN), respectively, while it decreased with an increase in Ca2+/NH4+ and CO3(2-)/NH4+ molar ratios (Ca/N and CO3(2-)/N), respectively. The trends for NH4(+)-N removal at different pH and Mg/N levels were similar to the thermodynamic modeling predictions. The RSM analysis indicated that the factors including pH, Mg/N, C(N), Ca/N, (Mg/N)x (CO3(2-)/N), (pH)2, (Mg/N)2, and (C(N))2 were significant. Response surface plots were useful for understanding the interaction effects on NH4(+)-N recovery.

A full-scale biological treatment system application in the treated wastewater of pharmaceutical industrial park.

A full-scale combined biological system is used for the treatment of treated wastewater discharged from a pharmaceutical industrial park. This treated water is rich in NH(4)(+)-N (average in 86.4 mg/L), low in COD/NH(4)(+)-N (average in 3.4) and low in BOD(5)/COD ratio (average in 0.24) with pH varying from 7.16 to 7.78. The final effluent of the combined treatment process was stably below 100mg/L COD and 20mg/L NH(4)(+)-N, separately, with organic loading rate of 4954 kg COD/d and 92.5 kg NH(4)(+)-N/d. It is found that the BOD(5)/COD ratio could be raised from 0.24 to 0.35, and the production of total VFAs account for 9.57% of the total COD via the treatment of hydrolysis/acidification. MBBR and oxidation ditch represent 35.4% and 60.7% of NH(4)(+)-N removal, 30.2% and 61.5% of COD removal, separately, of the total treatment process. PCR-DGGE is used for microbial community analysis of MBBR and oxidation ditch.