Effects of solid retention time and exposure mode to electric current on Remazol Brilliant Violet removal in an electro-membrane bioreactor.

The performance of an electrochemically assisted anoxic-oxic membrane bioreactor (A/O-eMBR) was assessed as an alternative for azo dye (Remazol Brilhant Violet (RBV)) removal from simulated textile wastewater. The A/O-eMBR was operated under three experimental conditions (runs I, II, and III), in which different solids retention time (SRT) (45 and 20 d) and exposure mode to electric current (6'ON/30'OFF and 6'ON/12'OFF) were assessed. The reactor exhibited excellent decolorization performance for all runs, with average dye removal efficiency ranging from 94.

Application of a phosphonium-based ionic liquid for reactive textile dye removal: Extraction study and toxicological evaluation.

Textile dyeing processes are known for their negative environmental impacts due to the production of aqueous effluents containing toxic dyes. Therefore, new wastewater treatment processes need to be developed to treat such effluents, including Liquid-Liquid Extraction (LLE) process using Ionic Liquids (IL). This work aimed to evaluate the application of the hydrophobic IL trihexyltetradecylphosphonium decanoate to extract black, navy, and royal reactive dyes from water and evaluate the toxicological aspects of the resulting water stream.

Textile azo dyes discolouration using spent mushroom substrate: enzymatic degradation and adsorption mechanisms.

This study evaluated the adsorption and enzymatic degradation of azo dyes when using SMS. The laccase present in the SMS was characterised, and the maximum activity was obtained at pH 2, a temperature of 45°C, a Michaelis-Menten constant (K) of 0.264 mM, and a maximum reaction rate (V) of 117.

Biostimulation of sulfate-reducing bacteria and metallic ions removal from coal mine-impacted water (MIW) using shrimp shell as treatment agent.

This paper comprises several assays aiming to identify the basis for the bioremediation of mine-impacted water (MIW). To do so, the conditions for build anoxic microcosms for treating this effluent were varied, containing MIW, and a source of chitin, to biostimulate sulfate-reducing bacteria (SRB). The chitin sources were: commercial chitin (CHIT) and shrimp shell (SS), which in addition to chitin, contains CaCO, and proteins in its composition.

Sulfate removal from mine-impacted water by electrocoagulation: statistical study, factorial design, and kinetics.

This work aimed to remove sulfate and acidity from mine-impacted water (MIW) via electrocoagulation (EC), a technique which stands as an advanced alternative to chemical coagulation in pollutant removal from wastewaters. The multiple electrochemical reactions occurring in the aluminum anode and the stainless steel cathode surfaces can form unstable flakes of metal hydroxysulfate complexes, causing coagulation, flocculation, and floatation; or, adsorption of sulfate on sorbents originated from the electrochemical process can occur, depending on pH value. Batch experiments in the continuous mode of exposition using different current densities (35, 50, and 65 A m) were tested, and a statistical difference between their sulfate removals was detected.

Membrane adsorption with polyacrylonitrile prepared with superfine powder-activated carbon, case study: separation process applied in water treatment containing diclofenac.

Polyacrylonitrile membranes (PAN) have high stability against chemical agents, making them suitable for a wide range of applications as such Ultrafiltration processes. Ultrafiltration membranes composed of PAN/Superfine powder activated carbon (S-PAC) mixtures can be a good research route, aiming the development of a new separation processes for water treatment. The association of materials to form a single product can have technological and economic advantages in separation processes.

Removal of organic matter and ammoniacal nitrogen from landfill leachate using the UV/HO photochemical process.

This study investigates the effects of pH, HO concentration and reaction time of the UV/HO photochemical process on the removal of organic matter and ammonia from biologically pre-treated landfill leachates in anaerobic stabilization ponds. The results show that the concentration of HO and the initial pH are significant factors, with no significant interaction between them. A pH of 3 is the optimum value for the UV/HO process for the removal of organic matter, resulting in 51.

Simultaneous adsorption of iron and manganese from aqueous solutions employing an adsorbent coal.

In this work, an adsorbent coal was characterized and its sorption properties for the removal of iron and manganese from aqueous solutions were determined. Energy dispersive X-ray (EDX) analysis and X-ray diffraction (XRD) identified the presence of quartz, magnetite and manganese oxide in the adsorbent coal. The results of the adsorption isotherms verified the adsorption of iron and manganese by adsorbent coal showing a linear behaviour and indicated that chemisorption and physisorption occurred.

Removal of coloured compounds from textile industry effluents by UV/H2O2 advanced oxidation and toxicity evaluation.

This study has investigated the reduction in coloured substances and toxic compounds present in textile industry effluent by the use of an advanced oxidation process using hydrogen peroxide (H2O2) as oxidant, activated by ultraviolet radiation. The investigation was carried out on industrial effluents, both raw and after biological treatment, using different concentrations of H2O2 in a photochemical reactor equipped with a 250 W high-pressure mercury vapour lamp. The results showed that after 60 minutes of ultraviolet irradiation a H2O2 concentration of 500 mg L(-1) was able to remove approximately 73% of the coloured compounds present in raw effluent and 96% of those present in biologically treated effluent.