Oxidation of simulated wastewater by Fe-catalyzed system: The selective reactivity of chlorine radicals and the oxidation pathway of aromatic amines.

Aromatic amines (AAs), a characteristic pollutant with electron-donating groups in textile industry, having high reactivity with reactive chlorine free radicals, is probably the precursor of chlorinated aromatic products in advanced oxidation treatment. In this study, Fe2+/peroxydisulfate (PDS)/Cl- and Fe2+/H2O2/Cl-systems were used to treat four kinds of AAs (5-Nitro-o-toluidine (NT), 4-Aminoazobenzol (AAB), O-Aminoazotoluene (OAAT), 4,4'-Methylene-bis(2-chloroaniline) (MBCA)) in simulated wastewater, and the selectivity of various reactive species to AAs, the oxidation law and pathway of AAs were explored. The results showed that dichloride anion radical (Cl2·-) could effectively oxidize four AAs, and chlorine radical (·Cl) was strongly reactive to AAB and MBCA, especially MBCA.

Formation of organic chloride in the treatment of textile dyeing sludge by Fenton system.

In the oxidation treatment of textile dyeing sludge, the quantitative and transformation laws of organic chlorine are not clear enough. Thus, this study mainly evaluated the treatment of textile dyeing sludge by Fenton and Fenton-like system from the aspects of the influence of Cl, the removal of polycyclic aromatic hydrocarbons (PAHs) and organic carbon, and the removal and formation mechanism of organic chlorine. The results showed that the organic halogen in sludge was mainly hydrophobic organic chlorine, and the content of adsorbable organic chlorine (AOCl) was 0.

Biomass waste as a clean reductant for iron recovery of iron tailings by magnetization roasting.

The magnetization roasting with coal as primary reductants adds cost and causes environmental pollution. Therefore, it is of great importance to investigate the biomass application as a reductant for magnetization roasting to recover iron from low-utilization iron tailings for emission mitigation and green utilization. This study systematically investigated the impact of biomass (pyrolysis gas from agricultural and forestry waste) as a reductant on the conversion of iron tailings to magnetite in magnetization roasting.

Nitrogen-enriched micro-mesoporous carbon derived from polymers organic frameworks for high-performance capacitive deionization.

Nitrogenization is an effective method for improving the capacitive deionization (CDI) performance of porous carbon materials. In particular, polymer organic frameworks with heteroatom doping, containing an ordered pore structure and excellent electrochemical stability, are ideal precursors for carbon materials for high-performance CDI. In this study, a nitrogen-enriched micro-mesoporous carbon (NMC) electrode was fabricated by carbonizing a Schiff base network-1 at 500, 600, and 700 °C.

Treatment of simulated textile sludge using the Fenton/Cl system: The roles of chlorine radicals and superoxide anions on PAHs removal.

The main content of this work is to investigate the removal of polycyclic aromatic hydrocarbons (PAHs: phenanthrene, anthracene, and fluoranthene) from simulated sludge solid phase employing an Fenton/Cl system under various Cl contents and pH values. The steady-state concentrations of the hydroxyl, chlorine, and dichloride anion radicals ([·OH], [·Cl], and [Cl]) in heterogeneous system were first measured using tert-butanol, nitrobenzene, and benzoic acid. The outcomes exhibited that increasing the Cl content from 50 to 2000 mg/L (pH = 3.

Comparison of the Fe/HO and Fe/PMS systems in simulated sludge: Removal of PAHs, migration of elements and formation of chlorination by-products.

In this study, polycyclic aromatic hydrocarbons (PAHs) at practical concentrations in the simulated sludge treated by the Fe/HO and Fe/peroxymonosulfate (PMS) systems were evaluated in terms of the PAHs (phenanthrene, anthracene, fluoranthene) removal, element migration, Cl effect, and chlorination by-product formation. The results indicated that according to the removal rate of PAHs, the optimal dosage of the Fe/PMS system (∑PAHs removal rate was 64.66 ± 2.

Ion-exchange polymers modified bacterial cellulose electrodes for the selective removal of nitrite ions from tail water of dyeing wastewater.

Ion-exchange polymer and modified carbonization bacterial cellulose (CBC) electrodes were fabricated using varying amounts of cation-exchange polymers (glutaric acid (GA) and sulfosuccinic acid (SSA)) and assembled within an asymmetric capacitive deionization unit (p-CDI). The performance of selective NO electro-adsorption was studied. The AC/CBC-SSA group showed a better salt adsorption capacity (14.

Algal toxicity induced by effluents from textile-dyeing wastewater treatment plants.

This research aimed to evaluate the alga Scenedesmus obliquus toxicity induced by textile-dyeing effluents (TDE). The toxicity indicator of TDE in alga at the physiological (algal growth), biochemical (chlorophyll-a (Chl-a) synthesis and superoxide dismutase (SOD) activity) and structural (cell membrane integrity) level were investigated. Then we further study the relationship among toxicity indicators at physiological and biochemical level, and supplemented by research on algal biomacromolecules.

Chlorobenzene levels, component distribution, and ambient severity in wastewater from five textile dyeing wastewater treatment plants.

Chlorobenzenes (CBs) present in synthetic dyes are discharged into natural waters during the treatment of textile dyeing wastewater, which may have adverse effects on human and environment. In this study, the existence and removal of 12 CBs in different units of five treatment plants were examined. The ecological risk of CBs in textile dyeing wastewater was assessed by ambient severity (AS) and risk quotients (RQs).

Effect of sintering temperature on mineral composition and heavy metals mobility in tailings bricks.

In this study, the mixing mechanism and phase transition process of different metals during the sintering of tailings bricks with four different metal oxides (CuO, PbO, ZnO, and CdO) at temperatures ranging from 700 to 1100 °C for 2 h were investigated. The properties of the sintered product was characterized and analyzed, and the results showed that the main crystalline phases are quartz, cristobalite, hematite, and mullite while the metal oxides are ascribed to copper ferrite spinel (CuFeO), gahnite (ZnAlO), zinc ferrite spinel (ZnFeO), lead feldspar (PbAlSiO), and cadmium feldspar (CdAlSiO). Further analysis indicates that the heavy metals were transited into spinel or silicate structures with favorable efficiency.

Treatment of 3,3'-dimethoxybenzidine in sludge by advance oxidation process: Degradation products and toxicity evaluation.

Studies on the oxidation products of organic pollutants and their toxicity in textile dyeing sludge after the sludge was treated by the advance oxidation processes were limited, since textile dyeing sludge was a complicated mixture. For the first time, simulated sludge was used to study the degradation mechanism of 3,3'-dimethoxybenzidine (DMB) during the combined ultrasound-Mn(VII) treatment. The toxicity of DMB and its products was also evaluated.

Treatment of a simulated sludge by ultrasonic zero-valent iron/EDTA/Air process: Interferences of inorganic salts in polyaromatic hydrocarbon removal.

Understanding the occurrence states of persistent organic pollutants such as polycyclic aromatic hydrocarbons (PAHs) in textile dyeing sludge is the key to their further treatment and disposal. Here, the effects of inorganic salts (silicate, sulfate, phosphate, hydroxide, and iron salts) that were typically rich in textile dyeing sludge on PAH adsorption by sludge and PAH degradation by an ultrasound (US) combined zero-valent iron/EDTA/Air (ZEA) system were studied in a simulated sludge system. The results showed that the simulated sludge containing inorganic salts had a larger specific surface area, which was beneficial for the adsorption of PAHs.

Sono-advanced Fenton-like degradation of aromatic amines in textile dyeing sludge: efficiency and mechanisms.

In this paper, a novel strategy integrating ultrasound (US) with a Fenton-like (zero-valent iron/EDTA/air, ZEA) process was proposed for the removal of the refractory and carcinogenic aromatic amines (AAs) in textile dyeing sludge for the first time. The operating condition was optimized as 1.08 W/cm ultrasonic density, 15 g/L ZVI, and 1.

The agricultural use potential of the detoxified textile dyeing sludge by integrated Ultrasound/Fenton-like process: A comparative study.

Enhancing industrial sludge detoxification is of scientific and practical significance in confronting urban development and stringent environmental regulations. A strategy combining ultrasound (US) with the zero-valent iron/EDTA/Air (ZEA) process was proven to be eco-friendly, being efficient in the removal of toxic compounds from textile dyeing sludge in our previous studies. In this paper, therefore, the detoxification effects of three advanced oxidation processes (US, ZEA, US/ZEA) on textile dyeing sludge were comparatively evaluated for the first time through alteration of the sludge's physico-chemical parameters (e.

Solar Photothermal Electrodes for Highly Efficient Microbial Energy Harvesting at Low Ambient Temperatures.

Temperature is an important parameter for the performance of bioelectrochemical systems (BESs). Energy-intensive bulk water heating has been usually employed to maintain a desired temperature for the BESs. This study concerns a proof-of-concept of a light-to-heat photothermal electrode for solar heating of a local electroactive biofilm in a BES for efficient microbial energy harvesting at low temperatures as a replacement for bulk water heating approaches.

Formation of lead ferrites for immobilizing hazardous lead into iron-rich ceramic matrix.

A strategy of immobilizing lead in the framework of ferrite-ceramic matrix, to reduce its environmental hazard was explored in this study. The mechanisms of incorporating lead into lead ferrites (δ-phase (2PbO·FeO), γ-phase (PbO·(2-2.5)FeO) and β-phase (PbO·(5-6)FeO)) was revealed by observing the phase transformation in the products.

Toxicity evaluation of textile dyeing effluent and its possible relationship with chemical oxygen demand.

Textile dyeing wastewater was the focus of much research because of its adverse effect on aquatic biota. In the present research, textile dyeing influent and effluent samples were collected from four textile dyeing wastewater treatment plants (TDPs) in Guangdong province, China, and their conventional indicators and toxicity were examined to reveal relationships. The relationship between toxicity and chemical oxygen demand (COD) was clearly established at individual TDPs.

Inhibitory effect of cadmium(II) ion on anodic electrochemically active biofilms performance in bioelectrochemical systems.

Cadmium(II) ion can affect the anode performance of bioelectrochemical systems (BES); however, how the presence of Cd affect the extracellular electron transfer of anodic electrochemically active biofilms (EABs), the microbial viability and species composition of microorganism on the anode remain poorly understood. Here, we investigated the inhibitory effect of Cd at different concentrations on the electrochemical performance and the biofilm community in mixed-culture enriched BES. The electrochemical performance of the BES was not inhibited at 2 mg L Cd, while higher concentrations of 5-20 mg L resulted in the decrease in the maximum power density, with 0.

Lead extraction from Cathode Ray Tube (CRT) funnel glass: Reaction mechanisms in thermal reduction with addition of carbon (C).

This study quantitatively determined the extraction of lead from CRT funnel glass and examined the mechanisms of thermally reducing lead in the products of sintering Pb-glass with carbon in the pre-heated furnace. The experimentally derived results indicate that a 90.3 wt% lead extraction efficiency can be achieved with 20 wt% of C addition at 950 °C for 3 min under air.

Electrochemical and microbial community responses of electrochemically active biofilms to copper ions in bioelectrochemical systems.

Heavy metals play an important role in the conductivity of solution, power generation and activity of microorganisms in bioelectrochemical systems (BESs). However, effect of heavy metal on the process of exoelectrogenesis metabolism and extracellular electron transfer of electrochemically active biofilms (EABs) was poorly understood. Herein, we investigated the impact of Cu at gradually increasing concentration on the morphological and electrochemical performance and bacterial communities of anodic biofilms in mixed-culture BESs.

Removal of polycyclic aromatic hydrocarbons (PAHs) from textile dyeing sludge by ultrasound combined zero-valent iron/EDTA/Air system.

This paper proposes a combined ultrasound (US) and zero-valent iron/EDTA/Air (ZEA) system to remove polycyclic aromatic hydrocarbons (PAHs) from textile dyeing sludge. The removal efficiencies of 16 PAHs using ZEA, US/Air (air injected into the US process), and US/ZEA treatments were investigated, together with the effects of various operating parameters. The enhanced mechanisms of US and the role of reactive oxygen species (ROS) in removing PAHs in the US/ZEA system were explored.

Sludge treatment by integrated ultrasound-Fenton process: Characterization of sludge organic matter and its impact on PAHs removal.

In this work, the impact of organic matter on the degradation of polycyclic aromatic hydrocarbons (PAHs) in textile dyeing sludge by ultrasound-Fenton process has been studied. Sludge organic matter (SOM) was characterized and the degradation efficiencies of PAHs at various oxidation intensities (Fenton's reagent of 20, 70, and 140mmol/L, ultrasonic densities of 0.36, 0.

Elimination and ecotoxicity evaluation of phthalic acid esters from textile-dyeing wastewater.

Phthalic acid esters (PAEs), presented in fabrics, surfactants and detergents, were discharged into the ecosystem during textile-dyeing wastewater treatment and might have adverse effects on water ecosystems. In this study, comprehensive investigations of the content and component distributions of 12 PAEs across different units of four textile-dyeing wastewater plants were carried out in Guangdong Province, China. Ecotoxicity assessments were also conducted based on risk quotients (RQs).

Transformation of hazardous lead into lead ferrite ceramics: Crystal structures and their role in lead leaching.

This study quantitatively determined the transformation of lead into lead ferrite ceramics and examined the influence of structural defects in lead ferrites (i.e. PbFeO, PbFeO and PbFeO) on lead leaching.