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Adsorptive separation membranes are widely utilized for the removal of toxic dyeing pollutants from dyeing wastewater. However, developing novel adsorption membranes with large adsorption capacities and enhanced adsorption performance for dyes in actual wastewater poses a significant challenge. This study focuses on the fabrication of crown ether-containing copolymer porous membrane (CRPM) and investigation of the adsorption performance of dyes from aqueous solutions. The morphology structure and pore size distribution revealed that the membrane was endowed with rich micropores and hierarchical porous structures. Three typical cationic dyes (MB, RhB, CV) and an anionic dye (MO) were selected to evaluate the adsorption behavior. The results of adsorption isotherms and kinetics demonstrated that the adsorption data could be well-fitted using the Freundlich and pseudo-first-order kinetic models, the thermodynamic parameters revealed that the adsorption process of dyes on CRPM is a spontaneous endothermic reaction. The membrane exhibited excellent adsorption performance for cationic dyes, with RhB displaying a higher maximum adsorption capacity than previously reported porous membranes. Notably, dynamic adsorption-desorption filtration demonstrated a rapid removal efficiency, with RhB, MB, and CV achieving removal rates of 99.09%, 98.63%, and 99.14% respectively, after five cycles. The filtration volume of the CRPM membrane was 2.4-fold greater than that of a traditional PVDF membrane when applied to actual dyeing wastewater. DFT theoretical calculations were employed to elucidate the adsorption mechanism. These calculations confirmed the significant roles of electrostatic interactions, H-bonds and π–π interactions in facilitating the high-efficiency adsorption of cationic dyes. These findings highlight the potential of the crown ether-containing copolymer as a promising material for adsorption separation membranes in the treatment of dyeing wastewater. [Display omitted] • The membrane possessed abundant micropores and a hierarchical porous structure. • The membrane indicated significant enhanced adsorption performance for cationic dyes. • Dynamic adsorption-desorption achieved >99% removal of cationic dyes in five cycles. • The membrane exhibited a 2.4-fold volume increase vs. traditional PVDF in dyeing wastewater filtration. • DFT calculations highlight electrostatic attraction and H-bonds' vital role in enhancing adsorption. [ABSTRACT FROM AUTHOR]

The treatment of dye-containing wastewater generated from textile industries is still a challenge, and various technologies, including physical, chemical and biological ones have been used. In recent years, the ionizing radiation (usually including gamma ray generated by radionuclide, such as 60Co and 137Cs, and electron beam generated by electron accelerator) technology has received increasing attention for degrading refractory or toxic organic pollutants in wastewater because of its unique advantages, such as no chemical additives, fast reaction rate, strong degradation capacity, high efficiency, flexibility, controllability. Compared to the conventional wastewater treatment processes, ionizing radiation technology, as a disruptive wastewater treatment technology, is more efficient for the decolorization and degradation of dyes and the treatment of dye-containing wastewater. In this paper, the recent advances in the treatment of dye-containing wastewater by ionizing radiation, in particular by electron beam (EB) radiation were summarized and analyzed, focusing on the decolorization and degradation of various dyes. Firstly, the formation of various reactive species induced by radiation and their interactions with dye molecules, as well as the influencing factors on the removal efficiency of dyes were discussed. Secondly, the researches on the treating dye-containing wastewater by electron beam radiation technology were systematically reviewed. Then, the decolorization and degradation mechanisms by electron beam radiation were further discussed in detail. And the integrated processes that would contribute to the advancement of this technology in practical applications were examined. More importantly, the recent advances of electron beam radiation technology from laboratory to application were reviewed, especially successful operation of dye-containing wastewater treatment facilities in China. And eventually, current challenges, future research directions, and outlooks of electron beam radiation technology were proposed for further advancing this technology for the sustainable development of water resources. [Display omitted] • The treatment of dye-containing wastewater is still a challenge. • Advances in dye-containing wastewater treatment by EB were summarized and analyzed. • Mechanisms of dye decolorization and degradation by EB were discussed in detail. • EB is more efficient for the decolorization and degradation of dyes. • Challenges, future directions and outlooks of EB technology were proposed. [ABSTRACT FROM AUTHOR]

Heterogeneous photocatalysis namely titanium dioxide (TiO 2 ) supported on coconut shell biochar (BC) was synthesized by sol-gel method (calcined at 450 °C) in the paper, which was innovatively applied to the decolorization of Reactive Brilliant Blue KN-R. The transmission electron microscopy (TEM) and X-ray diffraction patterns (XRD) results demonstrated that anatase TiO 2 film was firmly immobilized on the surface and pores of BC. The photocatalysis tests under UV high pressure xenon lamp (300 W) showed highest decolorization efficiency occurred at strong acid and alkali conditions (pH = 1 and 11) reached as 99.71% and 96.99% respectively within 60 min. Therefore, the TiO 2 /BC composites demonstrated both photocatalytic and adsorption capacity on KN-R decolorized, and presented quite durable and reusable in regeneration cycles, indicating a widely application possibility in anthraquinones dyeing wastewater treatment. [ABSTRACT FROM AUTHOR]

In present study, a hydrolysis acidification (HA) reactor was used for simulated dyeing wastewater treatment. Co-substrates included starch, glucose, sucrose, yeast extract (YE) and peptone were fed sequentially into the HA reactor to enhance the HA process effects. The performance of the HA reactor and the microbial community structure in HA process were investigated under different co-substrates conditions. Results showed that different co-substrates had different influences on the performance of HA reactor. The highest decolorization (50.64%) and COD removal rate (60.73%) of the HA reactor were obtained when sucrose was as the co-substrate. And it found that carbon co-substrates starch, glucose and sucrose exhibited better decolorization and higher COD removal efficiency of the HA reactor than the nitrogen co-substrates YE and peptone. Microbial community structure in the HA process was analyzed by Illumina MiSeq sequencing. Results revealed different co-substrates had different influences on the community structure and microbial diversity in HA process. It was considered that sucrose could enrich the species such as Raoultella , Desulfovibrio , Tolumonas , Clostridium , which might be capable of degrading the dyes. Sucrose was considered to be the best co-substrate of enhancing the HA reactor’s performance in this study. This work would provide deep insight into the influence of many different co-substrates on HA reactor performance and microbial communities in HA process. [ABSTRACT FROM AUTHOR]

Domestic wastewater treatment plants as a reservoir of antibiotic resistance genes (ARGs) have received much attention, but the effect of dyes on the propagation of ARGs has rarely been investigated. In this study, we investigated the differences in distributions of ARGs and microbial communities using high-throughput qPCR and 16S rRNA gene sequencing, respectively, between mixed (dyeing and domestic) wastewater and domestic sewage. The relative abundance of ARGs in inflows of mixed wastewater (IW2 and IW3) was higher than that of domestic wastewater (IW1). The relative abundance of mobile genetic elements in the inflow of textile dyeing wastewater (IDW3) was 3- to 13-fold higher than that in other samples. Moreover, in IDW3, some distinct high abundance ARGs, particularly operons encoding efflux pumps (such as acrR-01 , acrB-01 and acrF ), were significantly correlated with Streptococcus of the Firmicutes. To explore why the abundance of ARGs was relatively high in mixed wastewater, six representative types of organic compounds in textile dyeing wastewater were used to test the effect on plasmid-based conjugative transfer from E. coli HB101 to E. coli NK5449. These six compounds all facilitated the transfer of resistance-carrying RP4 plasmid, and the highest transfer frequency (approximately 10 −5 -10 −3 ) was over 4- to 200-fold higher than that in the control group (approximately 10 −6 -10 −5 ). These results illustrated that the six common residual compounds, particularly low-dose substances in IDW3, could facilitate the dissemination of ARGs in aquatic environments. More importantly, this study revealed for the first time that dyeing contaminants influenced horizontal gene transfer (HGT) of ARGs. [ABSTRACT FROM AUTHOR]

A modified internal circulation (MIC) reactor with an external circulation system was proposed and the performance of treating dyeing wastewater using both MIC and typical IC reactor were compared. Utilization of the external circulation system in the MIC reactor could dramatically improve the mixing intensity of the biomass with the wastewater and resulted in better performance. The COD removal efficiency, biogas production, volatile fatty acids and effluent color were approximately 87%, 98 L d −1 , 180 mg L −1 and 100 times, respectively, in the MIC reactor with a hydraulic retention time of 5 h and organic loading rate of 15 kg COD m −3 d −1 . The hydrodynamics of the MIC reactor under different flows rate of external circulation were also analyzed using computational fluid dynamics (CFD) method. The optimal flow rate of external circulation was 12 L min −1 , which resulted in a corresponding up-flow velocity of 40 m h −1 . The consistency of the result between experiment and simulation validated the scientificity of CFD technique applied to numerical simulation of the MIC reactor. [ABSTRACT FROM AUTHOR]

Dyeing wastewater was known to have strong color and refractory organic pollutants. In this study irradiation alone was used for dyes wastewater treatment. This paper studies the effect of the concentrations of pollutants to its removal at various dosages using electron beam technology. Irradiation was effective in removing the highly colored and refractory organic compounds. The color removal for initial concentrations of 255 CU, 520 CU, 990 CU and 1900 CU treated using irradiation at 0.5kGy were 61%, 48%, 28% and 16%, respectively. However, at the dose of 108kGy and higher, the color removal between 87% and 96% were recorded with no apparent trend. COD removal also reported similar trend but at relatively lower removal percentage. The COD removal at 0.5kGy for initial COD concentrations of 57mg/l and 515mg/l were 10% and 0%, respectively. At irradiation dose of 108kGy, the removal for initial COD concentrations of 57mg/l and 515mg/l were 37% and 13%, respectively. This showed that concentrations of pollutants and dose of irradiation applied to remove color and COD were dependent to each other. [Copyright &y& Elsevier]

This study was conducted to assess the potential of a sponges-submerged anaerobic baffled reactor (SS-ABR) for enhancing the processing performance of azo dye-contaminated wastewater. A lab-scale four–compartment SS-ABR, with a total volume of 10 L, was operated at 30 °C for 180 days. A total of 14 polyurethane sponges were added in each compartment to treat synthetic wastewater including a commercial azo dye Hellozol HSR Reactive Black. During the entire operation, in synthetic wastewater, starch was used as a sole carbon source, and the true color level was maintained at 1050 ± 98 Pt/Co. Meanwhile, the hydraulic retention time (HRT) and total COD (T-COD) in the influent were changed to evaluate the SS-ABR treatment performance. After the start-up phase, true color and T-COD removal efficiencies were recorded as 65 ± 3% and 83 ± 2%, 68 ± 5% and 81 ± 4%, and 70 ± 5% and 84 ± 2% for HRT and influent T-COD concentration of 18.6 h and 260 mg L−1, 14.6 h and 260 mg L−1, and 14.6 h and 460 mg L−1, respectively. The microbial community analysis showed that bacterial groups involved in dye degradation, such as Clostridium sp., and sulfate-reducing bacteria Desulfomonile sp. and Desulfovibrio sp. were detected prominently in the SS-ABR. Interestingly, the SS-ABR exhibited the dominance of both Geobacter sp. and Methanosarcina sp., and their occurrences in all columns were proportional to each other, revealing the formation of syntrophic relationships. • A sponges-submerged ABR (SS-ABR) was performed for enhanced decolorization. • Treatment performance of SS-ABR was stable when HRT and organic load changes. • The dominance of genus Clostridium revealed its involvement in dye decolorization. [ABSTRACT FROM AUTHOR]