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Crosslinked copolymers for oil absorption were synthesized by copolymerizing styrene (St) with lauryl acrylate (LA), with ethylene glycol dimethacrylate as crosslinking agent. Suspension polymerization was conducted using benzoyl peroxide as initiator. The crosslinking reaction mechanism and the structure of the composite were characterized by FT-IR analysis. Effects of different polymerization conditions were studied through oil absorption tests. The oil absorbency was influenced mainly by the degree of crosslinking and the LA/St ratio. Optimal oil absorbency was obtained for St/LA = 1. The absorbency of copolymers was higher for the aromatic series by the affinity investigation toward different organic solutions. [ABSTRACT FROM AUTHOR]

Mixed TiO2 sol and SiO2nanoparticles in different proportions were added into PVDF membrane, and their effects on pure water flux, retention rate and mechanical properties of PVDF membrane were discussed. The SiCV TiO2/PVDF membrane surface and section structures were characterized by SEM, FT-IR, and XRD analyses. In addition, membrane mechanical properties and hydrophilicity were tested. The results indicated that mixed TiO2 sol and SiC>2 nanoparticles could increase both hydro-philic and mechanical strength of PVDF membrane. When the SiO2/TiO2 mixed ratio was 3:10, membrane performance was optimized (porosity 81%, flux 13.9 L·m-2·h-1·KPa, retention rate 78%, tensile strength maximum loading 50N, tensile stress 3.18MPa, tensile strain 18%). [ABSTRACT FROM AUTHOR]

The textile industry produces enormous quantities of dye wastewater, containing high salt and organic concentrations, which are therefore difficult to be treated. In this work, an asymmetric Poly(m-phenylene isophthalamide) (PMIA) nanofiltration membrane was prepared by phase inversion method in order to reduce the quantity of the disposed water and, at the same time, to reuse the treated water. The morphology of the resulting membrane was characterized by scanning electron microscopy (SEM) as well as atomic force microscopy (AFM), and the molecular weight cut-off of the membrane was estimated using different polyethylene glycol (PEG) solutions. The asymmetric membrane was also evaluated for the removal of three different anionic dyes (acid, direct and reactive dyes). The effects of various parameters, such as pressure, pH, feed temperature and the presence of salt were evaluated. It was observed that the rejections of three dyes were all above 95% under 0.7 MPa at 25 °C. Long-term operating experiments showed that the membranes with a 900 Da cut-off could be used to concentrate 100 mgfL saline direct blue 71 solution with a high flux (>50 L/m2.h), a high dye rejection (>96%) and a salt retention lower than 6%. The newly developed nanofiltration membrane is suitable for the treatment of dye effluents. [ABSTRACT FROM AUTHOR]

The removal of one kind of dye, acid red B (ARB), by two kinds of carbon nanotubes (CNTs), single-walled CNTs (SWCNTs) and muti-walled CNTs (MWCNTs), were investigated. The results show that CNTs have high adsorption capacity for ARB, and the adsorption capacities for SWCNTs and MWCNTs are 585 and 85 mg/g, respectively. Kinetic study shows that the equilibrium time for adsorption of ARB to CNTs is 60 min, and the adsorption kinetic can be well described by the pseudo-second-order model. The adsorption increases with the increase in solution pH, and coexisting NaCl and CaCl2 enhance the removal. [ABSTRACT FROM AUTHOR]