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New standards for drinking water treatment technology, this study examines the oxidation - coagulation - microfiltration process for As (III) removal efficiency, dynamic tests were carried out to simulate the reactor and membrane chemistry beaker test a small test reactor tests. In addition, conventional drinking water treatment processes for upgrading problems, this study was carried out ultrafiltration membrane filter effluent treatment system in a pilot. HOCl oxidation of As (III) kinetic results showed: pH neutral and weakly alkaline reaction rate quickly, HOCl with H 3 AsO 3 , H < sub> 2 AsO 3 - and HAsO 3 2 - of the reaction rate constants were (1.72 ± 0.11) × 10 3 , (2.10 ± 1.02) × 107 and (3.66 ± 0.79) × 108 mol / (L · s), the overall reaction rate constant is the weighted sum of the rate constants; derived from the Arrhenius equation HOCl with H 3 AsO 3 , H 2 AsO 3 - and HAsO 3 2 - the apparent activation energy was 65.3 × 10 3 , 72.6 × 10 3 and 95.7 × 10 3 J / mol; shows the effect of salt, NaOCl solution was only involved in the oxidation reaction of HOCl molecules; in acidic conditions, Cl-can speed up the reaction rate; reaction rate expression can be simulated by means of the reaction. The simulation of the reactor beaker experiment shows that the direct use of FeCl 3 Coagulation on As (III) removal efficiency is poor, when the As (III) the initial concentration of 140μg / L, the effluent total arsenic concentration of 54.1μg / L, and adding 0.30 mg / L of NaOCl solution, the effluent total arsenic only 0.5μg / L. When the raw water pH of 7.91, the oxidation reaction can be completely finished within 30 s, even NaOCl and FeCl 3 also added to the water, the water can still meet the requirements. In addition to the use of a small test MCR arsenic test, running conditions were optimized, when the raw water total arsenic concentration was 197.4μg / L, NaOCl and FeCl 3 dosage were 0.50 and 15 mg / L when , the average concentration of total arsenic in the water only 1.3μg / L. MCR effluent pH, turbidity, organic matter, iron and other ions indicators are to meet drinking water health standards. Membrane fouling resistance at a smaller proportion of total resistance, reducing FeCl 3 dosage membrane resistance can slow growth. The changes in particle size of membrane resistance small, and the distribution width (Span) changes in resistance of the membrane play a major role. Ultrafiltration Process filtered water in a pilot show that the process is reliable, stable water quality. Filtration flux, pre-chlorination, sludge method, gas-water ratio will affect the membrane resistance changes; membrane water turbidity ≤ 0.1 NTU guaranteed rate of 96.6 percent; membrane filter effluent CODMn process on the average removal rate and UV254 respectively, 9.38% and 13.14%; membrane process to ensure microbiological safety of the water; membrane process for the TOC removal rate was 7.2%; membrane processes for trihalomethanes and haloacetic acid precursor removal instability. Pre-chlorination significantly increases the membrane system of pharmaceutical costs, and energy major share of total operating costs.
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