Hydrogen-based sono-hybrid catalytic degradation and mitigation of industrially-originated dye-based pollutants

Hazardous pollutants in water bodies have increased global concern due to their considerable toxicity and threat to the environmental matrices. Conventional remediation approaches are futile for eliminating various toxic dyes and other related pollutants. Regulations compliances for wastewater expulsion have forced scientists to either introduce new methods or upgrade present technologies to attain operative deprivation and mineralization of pollutants. Advanced oxidation processes (AOPs) relying on the generation of highly reactive oxidizing radicals, like ^?O, and ^?OH are considered efficient to attain high mineralization of a large number of dye pollutants and many other organic contaminants. Compared to conventional AOPs, including photocatalysis, Fenton, photo-ferrioxalate, ozone/UV, ozonation, H₂O₂/UV, etc., sonolysis is a comparatively newer AOP that implicates the use of ultrasound irradiation for generating oxidizing radicals, leading to the degradation of recalcitrant dyes. Due to no chemical catalyst requirement and being executed at ambient pressure and temperature, ultrasound-assisted AOPs have become robust hybrid AOPs to degrade environmental contaminants. Ultrasound treatments to mitigate pollutants are important because of the cavitation phenomenon. This review focuses on the degradation of dyes through ultrasound-based advanced oxidation processes. Firstly, we have described the ecotoxicity and health hazards of dye pollutants, then different sono-based methods such as sono-hybrid Fenton (US + Fe⁺²/H₂O₂), Fenton like (Fe⁺³/H₂O₂) process, sono-hybrid photo-Fenton process (US + Fe²⁺/H₂O₂/UV system, sono-hybrid hydrogen peroxide (US + H₂O₂), sono-hybrid catalytic (photo/electro) processes have been examined in details for their efficacy for degradation of dyes in wastewater. Future perspectives of ultrasound-assisted AOPs for dyes removal have also been discussed.     

灯芯绒活性染料冷轧堆染色工艺

本文介绍了活性染料冷轧堆染色工艺优越性及一般工艺介绍，并说明了生产中应注意问题。     

雷马素染料用于冷轧堆工艺初探

1　小样试验这次试验选用12×16、64×128、8片6条纯棉灯芯绒漂白布,进行碱剂用量的选择和冷轧堆染色堆置时间的选择。1.1　工艺流程:浸轧染液→打卷堆置→水洗→皂洗→水洗→烘干1.2　浸轧液的组成:染液(克/升):雷马素染料X;尿素:100克/升。碱液(克/升):硅酸钠Y,烧碱液38°Be75毫升/升。规定的轧液量与总轧液量有关,根据混和装置(4∶1)的混和比,染料及尿素加至总液量的80%而硅酸钠和烧碱液则构成其余的20%。1.3　工艺条件,处方:染液　雷马素:R-X蓝:12g;RNL黄:7g;RB红:1g;尿素:100g/l;碱液则分别用A、B、C三种。A、硅酸钠500ml,烧碱75…     

新型香豆素系荧光染料的研究

以7-二乙氨基-4-氯-3-甲醛基香豆素为基础,合成了7只新型香豆素系的荧光染料,在不同浓度下测定了它们的吸收光谱和发射光谱,在稀溶液中用PPP－MO方法预测的结果证明,其组成与光谱性质相符。     

Side-chain motions in poly(methyl methacrylate)+SiO2 hosts of fluorescent dyes studied by thermally stimulated discharge currents: effects of confinement and blending

The thermally stimulated discharge (TSD) currents technique has been used to study different types of inter- and intra-molecular interactions between the components in poly(methyl methacrylate) (PMMA)-based systems. The TSD current signal of the side-chain dielectric β relaxation mode of PMMA has been comparatively studied in bulk PMMA, PMMA polymerized in-situ mesoporous silica-gel, and these matrices in the presence of polar and ionic (rhodamine 6G/Cl⁻) or non-polar (perylene derivatives) fluorescent dyes. The analysis of the TSD responses by means of partial heating and thermal sampling techniques indicates that polymer's confinement in SiO₂ induces, firstly, an increase of the distributed energy barriers of the β relaxation mode, and secondly, an enhancement of the contribution of the faster relaxation modes (at T<T_max(β)) in the overall strength of the β mechanism. Basic features of the β bands (i.e. peak maximum and distribution of activation energies) exclude the occurrence of strong interactions between the perylene derivatives and the carbonyl groups of PMMA. To contrary, coupling effects appear between the motions of the side-groups of PMMA and rhodamine 6G. The results are interpreted in view of counteracting structural (e.g. modification of the polymer's free volume) and surface (hydrogen-bond interphase interactions) effects of confinement and blending on the relaxation dynamics of the pendant groups.     

活性染料湿摩擦牢度提升剂的合成与应用

通过引入不同含量的聚醚三元醇制备具有不同分子内交联程度的有机硅改性季铵化阳离子水性聚氨酯,尝试其在活性染料湿摩擦牢度提升方面的应用。本文主要研究聚氨酯高分子交联度对其乳液粒径、湿摩擦色牢度提升力、固色织物柔软手感等主要应用性能的影响。结果表明：制备的水性聚氨酯可有效提升染色纺织品的湿摩擦色牢度,处理后纺织品的湿摩牢度可提高1～1．5级且对织物柔软性的影响较小。     

苎麻纤维的染色性能研究

根据苎麻纤维在不同前处理条件下的性能特点,用不同的活性染料,还原染料进行染色,并对苎麻纤维染色性能进行研究,以选择一些比较适合于苎麻纤维染色的染料。     

Green synthesis of Ni@Fe3O4 and CuO nanoparticles using Euphorbia maculata extract as photocatalysts for the degradation of organic pollutants under UV-irradiation

This paper presents a fast, biogenic and green method for the synthesis of highly stable and small sized metal nanoparticles (MNPs). This technique has some benefits compared to the conventional physical and chemical methods. It is simple, rapid, cheap and environmentally friendly. In addition, it does not require any costly or hazardous chemicals. The extracts of Euphorbia maculata aerial parts were used in a green synthesis method in order to prepare magnetic Ni@Fe₃O₄ and CuO NPs. Fourier transforms infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), ultraviolet–visible (UV–Vis), energy dispersive X-ray spectrometry (EDS), Brunauer-Emmett-Teller (BET) and thermo gravimetric-differential thermal analysis (TGA) analytical techniques were used for analyzing the green synthesized compounds. The photocatalytic activity of the synthesized NPs was tested in the degradation of different organic dye pollutants such as congo red (CR), methylene blue (MB) and Rhodamine B (RhB) under UV irradiation. The effects of different parameters such as nanoparticle dosage, contact time, pH, and initial dye concentrations on the capacity of the photocatalyst adsorption were also studied. The comparison of the photocatalytic activity of the biosynthesized nanoparticles reveals that the catalytic activity of CuO NPs is higher than that of Ni@Fe₃O₄ NPs. Furthermore, good photocatalytic stability of the NPs in the degradation of MB under UV light irradiation was observed after the recycling. The photocatalyst efficiency did not considerably change after four cycles, which indicated excellent photocatalytic stability.     

Artificial neural network optimization for removal of hazardous dye Eosin Y from aqueous solution using Co2O3-NP-AC: Isotherm and kinetics study

The present research is focused on the synthesis and characterization of cobalt (III) oxide (Co₂O₃) nanoparticle loaded on activated carbon to prepare an outstanding sorbent for the removal of eosin Y (EY) as hazardous dye from aqueous solution. The sorbent was identified by SEM and XRD analysis. The effect of solution pH, adsorbent dosage (0.005–0.02 g), contact time (0.5–30 min) and initial eosin Y concentration (30–80 mg L⁻¹) on the adsorption process was investigated and modeled by artificial neural network. Following optimization of variables, the experimental equilibrium data was analysis by Langmuir, Freundlich, Tempkin and D–R isothermal models and explored that the data well presented by Langmuir model with a maximum adsorption capacity of 555.56 mg g⁻¹ at 25 °C. Kinetic studies at various adsorbent dosage and initial EY concentrations show that high removal percentage (>90%) was achieved within 15 min of the start of every experiment at most conditions. The adsorption of EY follows the pseudo-second-order rate equation in addition to intraparticle diffusion model. The experimental data were applied to train the multilayer feed forward neural network with three inputs and one output with different algorithms and different numbers of neurons in the hidden layer. The minimum mean squared error (MSE) of 1.49e − 04 and determination coefficient of (R²) 0.9991.     

Porous g-C3N4 with enhanced adsorption and visible-light photocatalytic performance for removing aqueous dyes and tetracycline hydrochloride

Porous g-C_3N_4samples were obtained by simply calcining bulk g-C_3N_4in static air in a muffle oven.The photocatalytic performance of these samples was evaluated through the removal of aqueous organic dyes(methylene blue and methyl orange)and tetracycline hydrochloride under visible-light irradiation(λ420 nm).Compared to bulk g-C_3N_4,porous g-C_3N_4exhibited much better capability for removing these contaminants,especially under visible-light irradiation,due to the enlarged specific surface area and more efficient separation of photogenerated charge carries.In particular,porous g-C_3N_4obtained by calcining bulk g-C_3N_4in air at 525°C showed the highest visible-light-driven catalytic activity among these samples.Superoxide radical anions(·O_2~-)were found to be the primary active species responsible for photodegradation.