Occurrence, fate and ecological risks of 90 typical emerging contaminants in full-scale textile wastewater treatment plants from a large industrial park in Guangxi, Southwest China

Season and side-chain length affect the occurrences and behaviors of phthalic acid esters in wastewater treatment plants

Emerging pollutants (EPs) are prevalent in aquatic environments globally. Researchers strive to understand their occurrence and behavior prior to their release into the environment. In this study, we examined five wastewater treatment plants (WWTPs), collected 50 wastewater samples and 10 sludge samples. We explored the sources and destinations of phthalic acid esters (PAEs) within these WWTPs using mass balance equations. Wastewater treatment diminished the frequency and concentration of PAEs, and decreased the fraction of short-chain PAEs. We confirmed the increased concentration of PAEs post-primary treatment and modified the mass balance equation. Calculations suggest that weaker "the mix" in winter than in summer and stronger sedimentation in winter than in summer resulted in high efficiency of PAEs removal by winter wastewater treatment. The mass flux of biodegradation was influenced by the combination of biodegradation efficiency and the strength of the particular type of PAEs collected, with no seasonal differences. Mass fluxes for sludge sedimentation were mainly influenced by season and were higher in winter than in summer. This study enhances our understanding of emerging pollutants in manual treatment facilities and offers insights for optimizing wastewater treatment methods for water professionals.

Chemical-toxicological insights and process comparison for estrogenic activity mitigation in municipal wastewater treatment plants

Efforts in water ecosystem conservation require an understanding of causative factors and removal efficacies associated with mixture toxicity during wastewater treatment. This study conducts a comprehensive investigation into the interplay between wastewater estrogenic activity and 30 estrogen-like endocrine disrupting chemicals (EEDCs) across 12 municipal wastewater treatment plants (WWTPs) spanning four seasons in China. Results reveal substantial estrogenic activity in all WWTPs and potential endocrine-disrupting risks in over 37.5 % of final effluent samples, with heightened effects during colder seasons. While phthalates are the predominant EEDCs (concentrations ranging from 86.39 %) for both estrogenic activity and major EEDCs (phthalates and estrogens), with the secondary and tertiary treatment segments contributing 88.59 ± 8.12 % and 11.41 ± 8.12 %, respectively. Among various secondary treatment processes, the anaerobic/anoxic/oxic-membrane bioreactor (A/A/O-MBR) excels in removing both estrogenic activity and EEDCs. In tertiary treatment, removal efficiencies increase with the inclusion of components involving physical, chemical, and biological removal principles. Furthermore, correlation and multiple liner regression analysis establish a significant (p < 0.05) positive association between solid retention time (SRT) and removal efficiencies of estrogenic activity and EEDCs within WWTPs. This study provides valuable insights from the perspective of prioritizing key pollutants, the necessity of integrating more efficient secondary and tertiary treatment processes, along with adjustments to operational parameters like SRT, to mitigate estrogenic activity in municipal WWTPs. This contribution aids in managing endocrine-disrupting risks in wastewater as part of ecological conservation efforts.

Synthesis, characterization, and application of Cu-substituted LaNiO3 perovskites as photocatalysts and/or catalysts for persulfate activation towards pollutant removal

The presence of emerging contaminants in environmental aqueous matrices is an ever-growing problem, since conventional wastewater treatment methods fail to adequately remove them. Therefore, the application of non-conventional methodologies such as advanced oxidation processes is of great importance to tackle this modern problem. Photocatalysis as well as catalytic activation of persulfates are promising techniques in this field as they are capable of eliminating various emerging contaminants, and current research aims to develop new materials that can be utilized for both processes. In this light, the present study focused on the use of a simple sol-gel-combustion methodology to synthesize Cu-substituted LaNiO3 perovskite materials in an attempt to improve the photocatalytic and catalytic performance of pure LaNiO3, using molar ratios of Cu:Ni that have not been previously reported in the literature. The morphological, structural, and optical features of the synthesized materials were characterized by a series of analytical techniques (e.g., X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, diffuse reflectance spectroscopy, etc.). Also, their performance as photocatalysts, persulfate anion activators and simultaneously as photocatalysts/persulfate anion activators (hybrid) was evaluated by conducting laboratory-scale experiments using phenol (phenolics) as a model emerging contaminant. Interestingly, the results revealed that LaCu0.25Ni0.75O3 exhibited the best efficiency in all the applied processes, which was mainly attributed to the introduction of oxygen vacancies in the structure of the substituted material. The contribution of selected reactive species in the hybrid photocatalytic/catalytic experiments utilizing LaCu0.25Ni0.75O3 as a (photo)catalyst was investigated using appropriate scavengers, and the results suggested that singlet oxygen is the most dominant. Additionally, the stability of all synthesized perovskites was assessed by monitoring the concentration of the leached Cu and/or Ni cations at the end of every applied process. Finally, the reusability of LaCu0.25Ni0.75O3 was evaluated in three consecutive catalytic cycles using the hybrid experiment methodology, as this process demonstrated the best efficiency in terms of phenolics removal, and the results were rather promising.

Cleaner production evaluation system for textile industry: An empirical study from LCA perspectives

The contradiction between the rapid textile expansion and intensive energy consumption, highly environmental pollution calls for the adoption of cleaner production (CP). However, current evaluation system mainly targeted on CP at production stage, guidance and support on the life cycle assessment is still in its infancy. Meanwhile few studies brought the combination of water conservation and carbon reduction into considerations. This study compared the existing CP evaluation systems including guidelines for the whole industry, standards for textile industry and indicators for the dyeing and finishing sector by quantifying the differences of indicator score compositions. Comparisons analysis from six aspects suggested that all the evaluation systems had relevant indicators regarding "pollutant emissions". "Management", "process equipment and techniques" and "resource and energy consumption" have also been well concerned while "product characteristic" seemed to be overlooked at current stage. From the perspective of whole life cycle, the key of textile processing is the "printing and dyeing" (44.23 %) followed by "fabric manufacturing"(28.85 %) and setting (15.38 %). With regards to the environmental impacts, resources depletion gained the highest attention since their indicator scores reached up to 25.71 %, 18.47 % and 20.62 % for EMAS, ERG 2018 and HJ-1852006. Cleaner production awareness and social impact also played significant roles in ISO 14031:2021 and WMG. Subsequently, a set of new comprehensive CP evaluation indicator system was established, including 3 scopes and 7 goals. The newly-built indicator system incorporated with life cycle perspectives gave a powerful tool to measure the CP level in textile industry and of CP will benefit from water reuse and energy utilization with high efficiency.

Long-term stable and efficient degradation of ornidazole with minimized by-product formation by a biological sulfidogenic process based on elemental sulfur

Conventional biological treatment processes cannot efficiently and completely degrade nitroimidazole antibiotics, due to the formation of highly antibacterial and carcinogenic nitroreduction by-products. This study investigated the removal of a typical nitroimidazole antibiotic (ornidazole) during wastewater treatment by a biological sulfidogenic process based on elemental sulfur (S0-BSP). Efficient and stable ornidazole degradation and organic carbon mineralization were simultaneously achieved by the S0-BSP in a 798-day bench-scale trial. Over 99.8 % of ornidazole (200‒500 μg/L) was removed with the removal rates of up to 0.59 g/(m3·d). Meanwhile, the efficiencies of organic carbon mineralization and sulfide production were hardly impacted by the dosed ornidazole, and their rates were maintained at 0.15 kg C/(m3·d) and 0.49 kg S/(m3·d), respectively. The genera associated with ornidazole degradation were identified (e.g., Sedimentibacter, Trichococcus, and Longilinea), and their abundances increased significantly. Microbial degradation of ornidazole proceeded by several functional genes, such as dehalogenases, cysteine synthase, and dioxygenases, mainly through dechlorination, denitration, N-heterocyclic ring cleavage, and oxidation. More importantly, the nucleophilic substitution of nitro group mediated by in-situ formed reducing sulfur species (e.g., sulfide, polysulfides, and cysteine hydropolysulfides), instead of nitroreduction, enhanced the complete ornidazole degradation and minimized the formation of carcinogenic and antibacterial nitroreduction by-products. The findings suggest that S0-BSP can be a promising approach to treat wastewater containing multiple contaminants, such as emerging organic pollutants, organic carbon, nitrate, and heavy metals.

Development of a Novel Energy Saving and Environmentally Friendly Starch via a Graft Copolymerization Strategy for Efficient Warp Sizing and Easy Removal

Warp sizing is a key process in textile production. However, before the yarn/fabric finishing, such as dyeing, the paste adhering to the warp must be eliminated to ensure optimal dyeing properties and the flexibility of the fabric. Therefore, the sizing will often consume a lot of energy and produce a lot of industrial wastewater, which will cause serious harm to the environment. In this study, we have developed an energy saving and environmentally friendly starch-based slurry by modifying natural starch with acrylamide. The paste has excellent viscosity stability and fiber adhesion, and exhibits excellent performance during warp sizing. In addition, the slurry has good water solubility at 60-70 °C, so it is easy to desize at low temperatures. Because of this, the sizing of the warp can be deslimed directly from the yarn during subsequent washing processes. This work can not only reduce some costs for the textile industry, but also achieve the purpose of energy conservation and emission reduction.

The evolution of endocrine disruptor chemical assessments worldwide in the last three decades

Endocrine Disrupting Chemicals (EDCs) encompass a wide variety of substances capable of interfering with the endocrine system, including but not limited to bisphenol A, organochlorines, polybrominated flame retardants, alkylphenols and phthalates. These compounds are widely produced and used in everyday modern life and have increasingly been detected in aquatic matrices worldwide. In this context, this study aimed to carry out a literature review to assess the evolution of EDCs detected in different matrices in the last thirty years. A bibliometric analysis was conducted at the Scopus, Web of Science, and Google Scholar databases. Data were evaluated using the Vosviewer 1.6.17 software. A total of 3951 articles in English were retrieved following filtering. The results demonstrate a gradual and significant growth in the number of published documents, strongly associated with the increasing knowledge on the real environmental impacts of these compounds. Studied were mostly conducted by developed countries in the first two decades, 1993 to 2012, but in the last decade (2013 to 2022), an exponential leap in the number of publications by countries such as China and an advance in research by developing countries, such as Brazil, was verified.

Association between co-exposure to phenols, phthalates, and polycyclic aromatic hydrocarbons with the risk of frailty

The phenomenon of population aging has brought forth the challenge of frailty. Nevertheless, the contribution of environmental exposure to frailty remains ambiguous. Our objective was to investigate the association between phenols, phthalates (PAEs), and polycyclic aromatic hydrocarbons (PAHs) with frailty. We constructed a 48-item frailty index using data from the National Health and Nutrition Examination Survey (NHANES). The exposure levels of 20 organic contaminants were obtained from the survey circle between 2005 and 2016. The association between individual organic contaminants and the frailty index was assessed using negative binomial regression models. The combined effect of organic contaminants was examined using weighted quantile sum (WQS) regression. Dose-response patterns were modeled using generalized additive models (GAMs). Additionally, an interpretable machine learning approach was employed to develop a predictive model for the frailty index. A total of 1566 participants were included in the analysis. Positive associations were observed between exposure to MIB, P02, ECP, MBP, MHH, MOH, MZP, MC1, and P01 with the frailty index. WQS regression analysis revealed a significant increase in the frailty index with higher levels of the mixture of organic contaminants (aOR, 1.12; 95% CI, 1.05-1.20; p < 0.001), with MIB, ECP, COP, MBP, P02, and P01 identified as the major contributors. Dose-response relationships were observed between MIB, ECP, MBP, P02, and P01 exposure with an increased risk of frailty (both with p < 0.05). The developed predictive model based on organic contaminants exposure demonstrated high performance, with an R2 of 0.9634 and 0.9611 in the training and testing sets, respectively. Furthermore, the predictive model suggested potential synergistic effects in the MIB-MBP and P01-P02 pairs. Taken together, these findings suggest a significant association between exposure to phthalates and PAHs with an increased susceptibility to frailty.