Study On The Processing Optimization And Equipment Development Of A Pulse Biological Filter

Rural sewage treatment technology starts late in China, the technology and management level of sewage treatment facilities are still backward, there is no enough professional management and maintenance, and built-up facilities cannot play normal function in most cases. This paper aims at realizing the standardized construction of rural sewage treatment facilities, on the basis of existing research and application results, with process parameters optimization it develops standardized pulse biological filter device suitable for the treatment of rural domestic sewage; and compiles operation and procedures for equipment manufacturing, manufacturing standard and maintenance.The sewage was taken as the sample. The research uses polypropylene sheet to build three assembled pulse biological filters, selects biological ceramsite filter material and building ceramsite filter material as filter material to investigate filter’s treatment effect on sewage in different filter material particle sizes, different filter material types, different cloth water time, different water cycles, different hydraulic loadings and reflux ratios, optimizes process parameters to determine suitable operation parameters of pulse biological filter. The main conclusions are as follows:Water distribution time, water distribution cycle and the hydraulic load have influence on filter running effect, with water distribution time shortening, removal rate of filter for COD, ammonia nitrogen and TN gradually declines. When water distribution time is controlled within 3.5～4.5 min, filter has a good sewage treatment effect; when water distribution cycle is controlled in 20～25 min, pulse biological filter running effect is good, when the water distribution cycle shortens, filter treatment effect decreases; with the increase of hydraulic loading, removal rate of filter for COD, ammonia nitrogen rises gradually, when hydraulic load increases to a certain value, there is a downturn in the treatment effect, when the hydraulic load varies between 6-7.2 m3/(m2·d), sewage treatment effect is good; in the filter ammonia nitrogen is removed along path, mainly concentrated in the lower filter material, filter has a good nitrifying ability and oxygen transfer performance; the orthogonal test shows that the optimal portfolio of filter operation is:hydraulic load 6.6 m3/(m2·d), water distribution cycle 20 min, water distribution time 4 min, reflux ratio 1:2～2.5.Setting the best operation parameters, pulse biological filter water distribution time is 3.5～4 min, water distribution cycle 20 min, water distribution load 6-7.2 m3/(m2·d), reflux ratio 1:2～2.5, when system is stable, mean concentration of COD, TN, NH4+-N and TP from filter with particle size Ф4～6mm biological ceramsite is 31.00±4.37,8.76±1.27,0.52±0.23,1.40±0.19 mg/L, average removal rate reaches 85.86±1.72%,58.71±3.88%,96.90±1.29%,48.03±6.52%; mean concentration of COD, TN, NH4+-N and TP from filter with Ф4～6mm building ceramsite filter material is 35.58±5.90,11.34±0.62,0.48±0.11,1.91±0.24 mg/L, average removal rate reaches 85.37±1.32%, 57.34±2.02%,97.83±0.55%,24.55±13.21%; mean concentration of COD, TN, NH4+-N and TP from filter with Ф5-12mm building ceramsite filter material is 45.51±4.05,9.77±0.69,0.69±0.20, 2.25±0.08 mg/L, average removal rate reaches 79.18±1.96%,53.80±1.61%,96.04±0.82%, 20.93±14.40%. Building filter material with particle size Ф4～6mm has a better effect than that with particle size Ф5～12mm. when particle size of ceramsite filter material and construction filter material are both Ф4～6mm, combined treatment effects are close.It summarizes the existing achievements, optimizes process parameters and reactor structure parameters, divides pulse biological filter into equipment shell, retainer layer, biological packing, water distribution system, intake and exhaust system, reflux system, control system, the water piping and other units; designs standardized pulse biological filter, proposes manufacturing standard and program for module units to quickly assemble standard equipment, compiles equipment maintenance procedures, in the last, realizes water treatment unit equalization of pulse biological filter.Research shows that developing normalization, standardization pulse biological filter with specification of maintenance has a great significance on pollution control and water environment quality improvement in rural lives.