Water features:

The main raw materials of starch production are potato,corn and wheat.Potato starch processing wastewater is mainly from transport and washing,separation,starch residue storage tank and condensation units.Separation wastewater is the main wastewater due to its large water volume and high COD,BOD content.Corn starch processing wastewater is mainly from immersion,germ separation,fiber washing,dehydration and other processes.Its water consumption and pollution contents are high,and including massive protein.Wheat starch processing wastewater is mainly from sedimentation tank supernatant liquid and centrifuge dehydration,the former’s organic matter content is low,while the latter’s is high.

Overall,starch wastewater’s organic and nitrogen content is high,its main components are protein,sugar,fat,and a certain amount of nutrients.If only using aerobic process,the energy consumption and cost are high,so it commonly uses "anaerobic + aerobic" process,anaerobic process can adopt HEIC,UASB,etc.And aerobic process often uses A/O,A/A/O,etc.According to engineering experience,we summarized a set of economic and effective treatment craft:"floation+HEIC+A/O pool",effluent achieves <Discharge standard of water pollutants for starch industry>,COD_cr≤100mg/l,BOD₅≤20mg/l,SS≤30mg/l,NH₃-N≤15mg/l.