The Sbr Treatment Of Agro-food Processing Wastewater

The properties of industrial wastewaters from agricultural and sideline food processing industry are the high-containing of organics and suspended substance. When the wastewater enters into the waters without reasonable treatment, it will induce death of aquatic animal and fish, and cause environmental pollution.Peninsula hilly area is a important zone in Shandong province, which contains much more small rivers. The rivers enter into the sea directly and the environmental capacity is low. Laiyang city is located in the middle of Jiaodong peninsula, for which food processing industry is the pillar industry. According to the statistic of environmental quality report during tenth five-year plan in Laiyang, food processing industry is the main pollution source in Laiyang. The pollution discharged into Wulong river through short-haul open channel or blind ditch, then enter into yellow sea. The majority of food processing industry in Laiyang is agricultural and sideline food processing. Thus it is important to study and perform the industrial wastewater treatment technics for agricultural and sideline food processing. There is significant mean for improving the water environmental quality in Laiyang, even in Peninsula hilly area.Sequencing batch reactor (SBR) is one of the most useful method in agricultural and sideline food processing wastewater treatment. In this thesis, based on studying of performance characteristics and process parameters of SBR method in agricultural and sideline food processing industrial wastewater, the technics was developed. The conditions, such as aeration intensity, aeration time, energy dissipation, dissolved oxygen and sludge concentration, were optimized.After the reconstructvie engineering, excellent effluent quality can be obtained and COD in the effluent was under 60 mg/L, which can meet the requisition of Pollutants Discharge Standard for Shandong Peninsula hilly area. Removal efficiency of COD was increased from 79.45% of primary engineering to 91.55%, and removal efficiencies of SS varied from 75.76% to 91.13%. The operating cost was reduced from 0.77 to 0.455 yuan/ton.The main advantages of reconstructive engineering are low operating cost, high treatment efficiency, and it can improve the water environmental quality in Laiyang and Peninsula hilly area. Additionally, it will offer some theory foundation and technical reference for the other similar engineerings.