The impact of organic cotton use and consumer habits in the sustainability of jean production using the LCA approach.

Due to the rise in clothing consumption per person and growing consumer awareness of environmental issues with products, the textile industry must adopt new practices for improving sustainability. The current study thoroughly investigates the benefits of using organic cotton fiber instead of conventional cotton fiber. Because of the extensive use of natural resources in the production of cotton, the primary raw material for textiles, which accounts for the environmental effects of a pair of jeans, a life cycle assessment methodology was used to examine these effects in four different scenarios. The additional scenarios were chosen based on the user preferences for washing temperatures, drying methods, and the type of cotton fiber used in the product. The environmental impact categories of global warming potential, eutrophication potential terrestrial ecotoxicity potential, acidification potential, and freshwater ecotoxicity potential were analyzed by the CML-IA method. The life cycle assessment results revealed that the lowest environmental impacts were obtained for scenario 4 with 100% organic cotton fiber with an improvement of 87% in terrestrial ecotoxicity potential and 59% in freshwater ecotoxicity potential. All of the selected environmental impacts of a pair of jeans are reduced in all scenarios when organic cotton is used. Additionally, consumer habits had a significant impact on all impact categories. Using a drying machine instead of a line dryer during the use phase is just as important as the washing temperature. The environmental impact hotspots for a pair of jeans were revealed to be the eutrophication potential, acidification potential, and global warming potential categories during the use phase, and the terrestrial ecotoxicity potential and freshwater ecotoxicity potential categories during the fabric manufacturing including cotton cultivation. The use of organic cotton as a raw material in manufacturing processes, as well as consumer preferences for washing temperature and drying methods, appears to have significant environmental impacts on a pair of jeans' further sustainable life cycle.

Removal of pesticides from secondary treated urban wastewater by reverse osmosis.

The residues of pesticides that reach water resources from agricultural activities in several ways contaminate drinking water resources and threaten aquatic life. This study aimed to investigate the performance of three reverse osmosis (RO) membranes (BW30-LE, SW30-XLE, and GE-AD) in rejecting four different pesticides (tributyl phosphate, flutriafol, dicofol, and irgarol) from secondary treated urban wastewater and also to elucidate the mechanisms underlying the rejection of these pesticides. RO experiments were conducted using pesticide-spiked wastewater samples under 10 and 20 bar transmembrane pressures (TMP) and membrane performances were evaluated. Overall, all the membranes tested exhibited over 95% rejection performances for all pesticides at both TMPs. The highest rejections for tributyl phosphate (99.0%) and irgarol (98.3%) were obtained with the BW30-LE membrane, while for flutriafol (99.9%) and dicofol (99.1%) with the GE-AD membrane. The increase in TMP from 10 to 20 bar did not significantly affect the rejections of all pesticides. The rejection performances of RO membranes were found to be governed by projection area as well as molecular weight and hydrophobicity/hydrophilicity of pesticides. Among the membranes tested, the SW30-XLE membrane was the most prone to fouling due to the higher roughness.

Life cycle sustainability assessment of a light rail transit system: Integration of environmental, economic, and social impacts.

The transition toward sustainable urban transportation has gained importance in recent decades. However, urban transportation has not been addressed for all dimensions of sustainability. This study presents a life cycle sustainability assessment of a light rail transit system in Kayseri, Turkey, by integrating environmental, economic, and social aspects. The sustainability performance of the light rail transit system is evaluated using a cradle-to-grave approach to assess three aspects of sustainability. For the environmental evaluation, a life cycle assessment was applied using SimaPro 8.4.1 PhD version based on ISO 14040 and 14044. The method, which includes nine environmental impact categories, was employed to assess the environmental performance of the light rail transit system with a functional unit of 1 passenger-km. For the economic assessment, life cycle costing was utilized with the functional unit of USD for 1 passenger-km. A social life cycle assessment was applied to assess the social performance of the light rail transit system based on guidelines published by the United Nations Environment Programme in collaboration with the Society of Environmental Toxicology and Chemistry. For the determination of social impacts, 11 subcategories and 18 social indicators were selected. The results showed that the global warming potential and abiotic depletion potential of the light rail system per passenger-km were 2.4E - 02 kg CO2 eq. and 2.7E - 01 MJ, respectively, with a service life of 50 years. The total life cycle cost of the light rail system was calculated as 0.046 USD for 1 passenger-km. The results also revealed that the main contributor to the total life cycle cost was energy cost, with 92% (2.88E + 08 USD) of the total cost. In the social performance evaluation, it is found that the industry performs well for society, the local community, and workers but has a weaker social performance for the consumer due to a weak feedback mechanism. Integr Environ Assess Manag 2021;17:1070-1082. © 2021 SETAC.

Preparation and characterization of PSF/PEI/CaCO3 nanocomposite membranes for oil/water separation.

Ultrafiltration (UF) is one of the significant advanced processes for oily wastewater treatment due to its clear advantages, for instance, ease in operation and efficient separation. The main drawback of these processes is the fouling problem and many researchers' effort on fabrication of high-performance membranes with higher hydrophilicity and antifouling properties. In this study, flat-sheet polysulfone (PSF)/polyethylenimine (PEI)/CaCO3 nanocomposite membranes were prepared by phase inversion method for oil/water emulsion separation. Structural properties of membranes were characterized by SEM, FT-IR, contact angle, tensile strength, and atomic force microscopy analysis. Increasing the CaCO3 nanoparticle loading exhibited the increased the water flux and BSA rejection. PSF/PEI/10 wt% CaCO3 nanocomposite membranes have 145 L/m2 h water flux at 2 bar with a contact angle of 84° and with 92% BSA rejection. All prepared CaCO3 nanocomposite membranes reached similar oil rejections at above 90%. Besides the higher water flux and oil removal efficiencies, 10 wt% of CaCO3 nanoparticle-blended PSF membranes has notable antifouling capacity with the highest flux recovery ratio (FRR) and lowest flux decay ratio (DR) values. The results showed that there is a great potential to use PSF/PEI/CaCO3 nanocomposite membranes for the treatment of oil water emulsions with higher permeability and antifouling capacity.

Removal of heavy metals from aluminum anodic oxidation wastewaters by membrane filtration.

Aluminum manufacturing has been reported as one of the largest industries and wastewater produced from the aluminum industry may cause significant environmental problems due to variable pH, high heavy metal concentration, conductivity, and organic load. The management of this wastewater with a high pollution load is of great importance for practitioners in the aluminum sector. There are hardly any studies available on membrane treatment of wastewater originated from anodic oxidation. The aim of this study is to evaluate the best treatment and reuse alternative for aluminum industry wastewater using membrane filtration. Additionally, the performance of chemical precipitation, which is the existing treatment used in the aluminum facility, was also compared with membrane filtration. Wastewater originated from anodic oxidation coating process of an aluminum profile manufacturing facility in Kayseri (Turkey) was used in the experiments. The characterization of raw wastewater was in very low pH (e.g., 3) with high aluminum concentration and conductivity values. Membrane experiments were carried out with ultrafiltration (PTUF), nanofiltration (NF270), and reverse osmosis (SW30) membranes with MWCO 5000, 200-400, and 100 Da, respectively. For the chemical precipitation experiments, FeCl3 and FeSO4 chemicals presented lower removal performances for aluminum and chromium, which were below 35% at ambient wastewater pH ~ 3. The membrane filtration experimental results show that, both NF and RO membranes tested could effectively remove aluminum, total chromium and nickel (>90%) from the aluminum production wastewater. The RO (SW30) membrane showed a slightly higher performance at 20 bar operating pressure in terms of conductivity removal values (90%) than the NF 270 membrane (87%). Although similar removal performances were observed for heavy metals and conductivity by NF270 and SW30, significantly higher fluxes were obtained in NF270 membrane filtration at any pressure that there were more than three times the flux values in SW30 membrane filtration. Due to the lower heavy metal (<65%) and conductivity (<30%) removal performances of UF membrane, it could be evaluated as pretreatment followed by NF filtration to protect and extend NF membrane life. The water treated by both NF and RO could be recycled back into the process to be reused with economic and environmental benefits.

Optimization of Co2+ ions removal from water solutions via polymer enhanced ultrafiltration with application of PVA and sulfonated PVA as complexing agents.

The paper presents the results of the studies of UF-complexation process applied for the removal of Co(2+) ions from water solutions. As binding agents for cobalt ions, the PVA polymer (M(w)=10,000) and its sulfonated form, synthesized in the laboratory, have been used. The method of experimental design and response surface methodology have been employed to find out the optimal conditions for the complexation process and to evaluate the interaction between the input variables, i.e., initial cobalt concentration, pH and amount of the polymer used, expressed as a polymer/Co(2+) ratio r. The data collected by the designed experiments showed that sulfonation of polymer has improved significantly the binding ability of PVA. The optimal conditions of cobalt ions complexation established by response surface model for non-sulfonated PVA polymer have been found to be as follows: the initial concentration of Co(2+)=5.70 mg L(-1), the ratio between polymer and metal ions, r=8.58 and pH=5.93. The removal efficiency of Co(2+) in these conditions was 31.81%. For sulfonated PVA polymer, the optimal conditions determined are as follows: initial concentration of [Co(2+)](0)=10 mg L(-1), r=1.2 and pH=6.5. For these conditions, a removal efficiency of 99.98% has been determined. The experiments showed that Co(2+) removal ability of sulfonated PVA was much higher than its non-sulfonated precursor. Although the polymer concentrations used in the tests with sulfonated PVA were approximately ten times lower than the non-sulfonated one, the removal efficiency of cobalt ions was significantly higher.

Biological treatment and nanofiltration of denim textile wastewater for reuse.

This study aims at coupling of activated sludge treatment with nanofiltration to improve denim textile wastewater quality to reuse criteria. In the activated sludge reactor, the COD removal efficiency was quite high as it was 91+/-2% and 84+/-4% on the basis of total and soluble feed COD, respectively. The color removal efficiency was 75+/-10%, and around 50-70% of removed color was adsorbed on biomass or precipitated within the reactor. The high conductivity of the wastewater, as high as 8 mS/cm, did not adversely affect system performance. Although biological treatment is quite efficient, the wastewater does not meet the reuse criteria. Hence, further treatment to improve treated water quality was investigated using nanofiltration. Dead-end microfiltration (MF) with 5 microm pore size was applied to remove coarse particles before nanofiltration. The color rejection of nanofiltration was almost complete and permeate color was always lower than 10 Pt-Co. Similarly, quite high rejections were observed for COD (80-100%). Permeate conductivity was between 1.98 and 2.67 mS/cm (65% conductivity rejection). Wastewater fluxes were between 31 and 37 L/m2/h at 5.07 bars corresponding to around 45% flux declines compared to clean water fluxes. In conclusion, for denim textile wastewaters nanofiltration after biological treatment can be applied to meet reuse criteria.