Study On Treatment Of Juice Wastewater By PVA Biological Process

The Juice wastewater is a kind of high concentrated organic wastewater.It is characterized by abundant solid extraneous components,high organism concentration and large variety of water components and quantity.It has caused serious environmental pollution.As the burgeoning industry,juice production developed rapidly in recent years.Subjecting to seasonal effects,it products only 4?7 months each year,the rest time is in a state of suspend production or deep processing.During production,the treatment technology needs to adapt to a great deal of high-concentration wastewater as soon as possible.Nowadays,PVA biological treatment process as a new wastewater treatment technology displayed some distinctive features,such as good quality and stability of water,high volume load,small occupation space,low surplus sludge volume and simple operation etc,in Japanese industrial wastewater disposal.Therefore,PVA biological process start-up and continuous operation of juice wastewater were deeply studied in this paper.Clearance mechanism of pollutants in PVA-gel carrier and activated sludge were also discussed on the basis of biofacies analysis.The main research contents and conclusions are as follows:(1)Under the conditions of p H value from 6.5 to 8.5,DO from 3.0 to 4.0 mg·L^-1 and volume load 0.5 kg COD·m^-3·d^-1,removal rates of COD,BOD₅and NH₃-N were above93%,99%and 96%respectively.It marks the reactor started-up successfully.(2)By experiments on the basis of started-up successfully.During 65 days continuous operation showed(the highest volume load 7.0 kg COD·m^-3·d^-1)that that COD,BOD₅ and NH₃-N removal rate above 90%,95%and 93%respectively,the average effluent COD,BOD₅ and NH₃-N reduced to 150.0 mg·L^-1,30.0 mg·L^-1and 3.8 mg·L^-1respectily by PVA biological process.(3)From the appearance and microcosmic changed of PVA-gel carrier,amount of aureus,filamentous bacteria and bacillus were enrichment in outer and inner of PVA-gel carrier.The treatment ability was improved by the vast majority of bacteria steadily adhere to the PVA-gel carrier surface and interior,the high enrichment of microorigims and dominant bacteria.Free bacteria and zoogloea bacteria were the main type?s microbe of activated sludge by microscope.Then,the reason for sludge yield(0.104 kg[MLSS]?kg^-1[COD])was lower is due to the breeding of bacteria produce excess sludge in the activated sludge tank through self oxidation decomposition disappear,greatly reduce the quantity of sludge.Figure 38,table 11,reference 62.