The high content of natural organic matter (NOM) is one of the challenging characteristics of peat water. It is also highly contaminated and contributes to some water-borne diseases. Before being used for potable purposes, peat water must undergo a series of treatments, particularly for NOM removal. This study investigated the effect of coagulation using aluminum sulfate coagulant and adsorption using powdered activated carbon (PAC) as a pretreatment of ultrafiltration (UF) for removal of NOM from actual peat water. After preparation and characterization of polysulfone (Psf)-based membrane, the system’s performance was evaluated using actual peat water, particularly on NOM removal and the UF performances. The coagulation and adsorption tests were done under variable dosings. Results show that pretreatment through coagulation–adsorption successfully removed most of the NOM. As such, the UF fouling propensity of the pretreated peat water was substantially lowered. The optimum aluminum sulfate dosing of 175 mg/L as the first pretreatment stage removed up to 75–78% NOM. Further treatment using the PAC-based adsorption process further increased 92–96% NOM removals at an optimum PAC dosing of 120 mg/L. The final UF-PSf treatment reached NOM removals of 95% with high filtration fluxes of up to 92.4 L/(m2.h). The combination of three treatment stages showed enhanced UF performance thanks to partial pre-removal of NOM that otherwise might cause severe membrane fouling.

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This article provides details of a study that fabricated interlayer-free pectin template silica membranes and then employed them in a series of experiments for the desalination of brackish water using pervaporation. The main objective of this research is to investigate the performance of the membranes in the desalination application and to look at ways of improving their mechanical stability.

This study shows, for the first time, the synthesis of a carbonised pectin templated silica thin-film material. The aim of this work is to investigate the vibration of carbon groups of pectin–silica xerogels using infrared spectroscopy and curve-fitting software. Thin films were prepared using a two-step acid–base catalysed sol-gel method, employing tetraethyl orthosilicate as the main precursor. Various concentrations of pectin (0.1 wt%, 0.5 wt% and 2.5 wt%) were used as templating agents. These were firstly dissolved in glycerol, and mixed with the silica thin-film material. The sols was then dried in an oven at 60°C for 12 h, and calcined in air using rapid thermal processing at 300°C and 400°C for 1 h. The results show that the concentration of carbon groups for samples calcined under 400°C is higher than that of samples calcined at 300°C – especially in the region of 800 cm−1 for silica-carbon. This clearly shows that the calcination temperature influences the polymerisation of carbon group templates in the silica matrices.

Wetland saline water is the enormous problem faced by rural people in Kalimantan, Indonesia. During rainy season, seawater intrudes wetland aquifer and turns water to saline. Application of membrane silica–pectin is eligible to solve this issue. Sadly, this water contains high concentration of organic matter that contributes to declining of membrane performance. Therefore, coagulation pretreatment is explored to enhance membrane filtration performance. The objective of this work is to investigate the optimum condition of coagulation pretreatment to enhance silica–pectin membrane performance for wetland saline water desalination. Sol gel process was employed to fabricate silica–pectin membrane and calcined via rapid thermal processing technique. Desalination was operated by pervaporation at 25–60°C. Maximum removal of organic matter UV254 was obtained at coagulant 30 g L−1 of 83.5% (pH 7). Combination processes between coagulation pretreatment and silica–pectin membranes offered high water flux at 60°C (12.2 kg m−2 h−1). The UV254 rejection of the feed water with coagulation is 43% higher than without applying coagulation pretreatment. Overall, salt rejection for all processes was extremely good (99.9%). Application of coagulation as pretreatment is promising to enhance performance of silica–pectin membrane for wetland water desalination.