Study And Design On Emergency Drinking Water By Magenetic Flocculation

Recently, natural disasters happened Frequently, for example, earthquakes, heavy rains, flash floods etc. in order to protect the drinking water source can be supplied fastly and securely in disaster areas, this paper intends to research and develop a fast treating speed, high efficiency, small area occupation magnetic flocullation equipment, which can provide technical support for the subsequent emergency water device treating different pollution degree of organic micro-polluted water and high turbidity water.First of all, we determined the process parameter by the experiment of micropolluted water routine flocculation and magnetic flocullation. The optimum coagulant for organic micro-polluted water and high turbidity water was PAC:the optimum doses for Grade IV, GradeV or worse than grade V organic micropollution water was 20mg/L,25-35mg/L and 30-40mg/L; the optimum PAC dosage for high turbidity water was 10mg/L, PAC doses could be increased to 15-20mg/L for higher turbidity water which was based with the suspended particles pollution. The optimum PAM doses was O.lmg/L. Magnetic particle conditons:the optimum dosage for Grade Ⅲ, Ⅳ, Ⅴ organic micropolluted water was 60,90, 100mg/L; the optimum magnetic particle doses for high turbidity water was 75mg/L; the best particle size was 320 mesh (45micron). The optimum hydrodynamics condition was 300r/min (10s) +300r/min (50s)+60r/min (6min), and sediment time was 5～10min.Then, comparing with the routine flocculation, the coatulation rate was highly increased which rise four times than the routine’s and the floc volume is half than it. in addition, the removal rate of CODMn, turbidity, ammonia nitrogen, total phosphorus, six-valence chromium were 69.8%,93.4%,36%,37% and 35%, the chroma removal rate was also good. Through the study of magnetic flocculation by microscopic mechanism, we found that magnetic particle was wrapped in the center of the floc as the floc nucleus, making the flocculation grow up fastly and increase the dencsity of the floc.Lastly, we designed a set of 10m3/h magnetic flocculation and separation system According to the experiment, including dosing tank, mechanical mixing equipment, the flocculation response device, sedimentation tank and magnetic separation system, to provide comprehensive reference for the project operation.