Distribution and Removal of Nonylphenol Ethoxylates and Nonylphenol from Textile Wastewater—A Comparison of a Cotton and a Synthetic Fiber Factory in Vietnam

New findings on the occurrence, removal, and risk assessment of nonylphenol and octylphenol in industrial wastewater treatment plants in Korea

Nonylphenol (NP) and octylphenol (OP), extensively used in industries, can disrupt the human endocrine system and cause significant ecological toxicity. Therefore, in this study, we aimed to reveal the occurrence and removal characteristics of NP and OP in 30 industrial wastewater treatment plants (IWWTPs). Specifically, this study focused on 13 NP isomers that have not been previously reported. Additionally, the potential environmental risk of NP and OP discharged from IWWTPs was assessed using a minimum dilution factor (MDF), proposed for the first time in this study. We showed that the concentration and proportion of the isomer NP11 were higher than those of the other isomers in the IWWTP influents and effluents. We also identified an activated sludge-activated carbon adsorption process suitable for removing NP and OP. Finally, we proposed the MDF value of 11 for the potential environmental risk assessment of NP and OP, revealing that OP poses a higher risk than NP when discharged into surface water. These findings underscore the importance of focusing on the isomer NP11 and OP in IWWTPs.

Environmental sustainability assessment of a polyester T-shirt - Comparison of circularity strategies

The considerable environmental burden of textiles is currently globally recognized. This burden can be mitigated by applying circular economy (CE) strategies to the commonly linear, short garment life cycles that end with incineration or landfill disposal. Even though all CE strategies strive to promote environmental sustainability, they might not be equally beneficial. Environmental data on different textile products is insufficiently available, which leads to complications when assessing and deciding on different CE strategies to be implemented. This paper studies the environmental impacts of a polyester T-shirt's linear life cycle through life cycle assessment (LCA) and evaluates the benefits attainable by adopting different CE strategies, and their order of priority, while noting uncertainty arising from poor data quality or unavailability. The LCA is complemented by assessing health and environmental risks related to the different options. Most of the linear life cycle's LCA-based impacts arise from use-phase washing. Hence, it is possible to reduce the environmental impact notably (37 %) by reducing the washing frequency. Adopting a CE strategy in which the shirt is reused by a second consumer, to double the number of uses, enables an 18 % impact reduction. Repurposing recycled materials to produce the T-shirt and recycling the T-shirt material itself emerged as the least impactful CE strategies. From the risk perspective, reusing the garment is the most efficient way to reduce environmental and health risks while washing frequency has a very limited effect. Combining different CE strategies offers the greatest potential for reducing both environmental impacts as well as risks. Data gaps and assumptions related to the use phase cause the highest uncertainty in the LCA results. To gain the maximum environmental benefits of utilizing CE strategies on polyester garments, consumer actions, design solutions, and transparent data sharing are needed.

Genotoxic activity of endocrine disrupting compounds commonly present in paper mill effluents

In the present study we evaluated cytotoxic and genotoxic activities of endocrine disrupting compounds (EDCs), including dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), benzyl butyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), bisphenol A (BPA), and nonylphenol (NP), which have been previously identified in effluents from two paper mills with different paper production technologies (virgin or recycled fibres). Moreover, we evaluated genotoxic activity of the effluents from these two paper mills and compared it to the activity of artificial complex mixtures consisting of the seven EDCs at concentrations detected in corresponding paper mill effluents. None of the EDCs was genotoxic in Salmonella typhimurium (SOS/umuC assay), while all induced DNA damage in human hepatocellular carcinoma (HepG2) cells (comet assay). After 4 h of exposure genotoxic effects were determined at concentrations ≥ 1 μg/L for BBP and DEHP, ≥10 μg/L for DMP, DEP, DBP, and BPA, and ≥100 μg/L for NP, while after 24 h of exposure DNA damage occurred at ≥10 μg/L for DBP, BPA and NP, and ≥100 μg/L for DMP, DEP, BBP and DEHP. The effluents and corresponding artificial mixtures of EDCs from paper mill that uses virgin fibres did not induce DNA damage in HepG2 cells, while the effluents and corresponding artificial mixtures for the paper mill that uses recycled fibres were genotoxic. Genotoxic activity of effluents was significantly higher compared to corresponding artificial mixtures suggesting the presence of further unknown compounds contributing to the effect. Wastewater monitoring based on chemical analysis is limited to determination of targeted compounds and does not take into account possible interactions between chemicals in mixtures. Therefore, it alone cannot provide an adequate information on potential toxic effects required for the assessment of genotoxic activity of real environmental samples and their potential threats to the environment and human health.

Submerged membrane filtration process coupled with powdered activated carbon for nonylphenol ethoxylates removal

A combination of a submerged membrane filtration system and powdered activated carbon (PAC) was investigated for nonylphenol ethoxylates removal. Both filtration flux and initial powdered activated carbon dosage had significant effects on the micropollutants removal efficiency. The best performance was achieved under the filtration flux of 20 L/m².h and the initial powdered activated carbon of 50 mg/L. The removal efficiencies of nonylphenol ethoxylates was obtained at 75±5% in the first 60 hours, and then decreased at 55±7% and 23±11% in the following hours, respectively. As observed, over 65% of dissolved organic carbon mass adsorbed into powdered activated carbon that was suspended in the bulk phase, and the remainder was adsorbed into powdered activated carbon that deposited on the membrane surface. It reveals that the combination between submerged membrane filtration and PAC could be an effective solution for enhancing removal of micropollutants from water.

Distribution and mass loads of xenoestrogens bisphenol a, 4-nonylphenol, and 4-tert-octylphenol in rainfall runoff from highly urbanized regions: A comparison with point sources of wastewater

This study pays a special attention to three phenolic endocrine disrupting compounds (EDCs), - bisphenol A (BPA), 4-nonylphenol (4-NP), and 4-tert-octylphenol (4-t-OP) - that are present in urban environments, resultant of several anthropogenic activities that can be also carried through rainfall runoff. We investigated the distributions of BPA, 4-NP, and 4-t-OP in Pearl River basin and estimated the mass loads in rainfall runoff, wastewater treatment plant (WWTP) effluents, and industrial wastewater from urbanized Huizhou and Dongguan regions. These three phenolic EDCs were detected frequently in tributaries and mainstream of Dongjiang River with the maximum 4-NP concentrations of 14,540 ng/L in surface waters and 3088 ng/g in sediments. BPA showed high concentrations in rainfall runoff samples with maximum concentrations of 5873 and 2397 ng/L in Huizhou and Dongguan regions, respectively, while concentrations for 4-NP and 4-t-OP were detected at tens to hundreds of nanograms per liter. Mass loads of phenolic EDCs from rainfall runoff were 3-62 times higher than those of WWTP effluents, suggesting rainfall runoff is an important source of phenolic EDCs into receiving waters. Sources and tributaries showed median to high estrogenic risks, while low to median risks were found in mainstream, implying the source control should be focused.

Nonylphenol ethoxylates biodegradation increases estrogenicity of textile wastewater in biological treatment systems

The formation of estrogenic intermediates, i.e. nonylphenol diethoxylate (NP2EO), nonylphenol monoethoxylate (NP1EO), and nonylphenol (NP), following nonylphenol ethoxylates (NPEOs) biodegradation in textile wastewater raises concerns about its endocrine disruptive activity, but the estrogenicity changes of textile wastewater throughout biological treatment processes remain unknown. In the present study, the estrogenicity of textile wastewater sampled from 10 wastewater treatment plants (WWTPs) were investigated using the reporter gene-based T47D-KBluc bioassay. Results showed that the estrogenicity of the textile wastewater significantly increased after either anaerobic or aerobic treatment in all WWTPs, with an average fold change of 3.21, although traditional pollutants were effectively removed. The estradiol equivalents of the effluent (ranging from 1.50 to 4.12 ng-E2/L) were generally higher than published effect based trigger values, indicating an increased risk for the receiving waters. Removal efficiency was high (84.46%) for NPEOs, but was low for NP2EO and NP1EO in the biological treatment processes. Nevertheless, NP had increased concentrations after the treatment. Bioanalytical equivalent concentration of the textile wastewater and that of NP2EO, NP1EO, and NP showed a good linear correlation, of which NP alone contributed more than 70% to the observed estrogenicity. Extending hydraulic retention time was found effective in reducing the estrogenicity as it allows relatively complete degradation of NP, which was further confirmed by running lab-scale A/O reactors fed with NP10EO. The results may extend our knowledge regarding the estrogenicity of textile wastewater and its reduction technologies used in WWTPs.

Natural or synthetic - how global trends in textile usage threaten freshwater environments

As the global demand for textiles increases, so to do the potential environmental impacts that stem from their production, use and disposal. Freshwater ecosystems are particularly at risk: rivers often act as the primary recipients of waste generated during the production of textiles and are subject to pollutants released during the broader lifecycle of a textile product. Here, we investigate how global technological and societal processes shape the way we produce, use and dispose of textiles, and what this means for the environmental quality and ecological health of freshwaters. We examine two predominant 'natural' and synthetic textiles (wool and Polyethylene terephthalate (PET), respectively), and find that risks to freshwater ecosystems vary throughout the lifecycle of these textiles; and across geographies, in-line with regulatory and economic landscapes. Woollen textiles pose most risk during the Production Phase, while PET textiles pose most risk during the Use and Disposal Phases. Our findings show that: (i) both 'natural' and synthetic textiles present substantial challenges for freshwater environments; and (ii) bespoke solutions are needed in areas of the world where the global division of labour and less stringent environmental regulations have concentrated textile production; but also in regions where high textile consumption combines with unsustainable disposal behaviours. Effective mitigation may combine technological advances with societal changes in market mechanisms, regulations, textile use and disposal.