Compared selection of pretreatment technology for cassava starch wastewater treated by anaerobic process

Cassava starch industrial wastewater has some characteristics such as high concentration of organic pollutant, high concentration of suspended solids and low pH value etc. If the wastewater is treated by anaerobic process, it is necessary to choose reasonable methods of pretreatment among Coagulation and precipitation, flotation and hydrolysis acidification etc. Full hydrolysis acidification is the best pretreatment technology because the cassava starch wastewater has good biodegradability. The actual treatment project of cassava starch wastewater shows that the volume of pretreatment structures is necessary to be satisfied with more than 12 hours of hydraulic retention time. Precipitation pool and hydrolysis acidification pool should be designed separately. The suspended solid is separated from the wastewater in precipitation pool, and also kept from the anaerobic reaction system. The macromolecular organic material is hydrolyzed fully in the hydrolysis acidification pool, and the efficiency of anaerobic treatment can be improved.