Effects of Cleaner Production Technologies of a Corn Starch Enterprise on Wastewater Treatment Effectiveness

The problem diagnosis was performed for EGSB+A/O wastewater treatment process of a corn starch enterprise, and the cleaner production renovation measure were proposed for the enterprise. The effects of the cleaner production renovation measure on wastewater treatment effectiveness were investigated. The results showed that the operational efficiency of EGSB reactor could be enhanced by adding a centrifuge in the main workshop and vertical flow sedimentation tank in wastewater pretreatment section. The average COD_Cr concentrations of the inlet and outlet were reduced by 59% and 62% respectively, and the specific methane production rate was increased by 45%. After renovation engineering, the average COD_Cr, BOD₅, NH₄⁺-N, SS concentrations of the effluent wastewater from the secondary sedimentation tank were reduced from 124, 31, 57 and 33 mg/L to 55, 9, 4.5 and 19 mg/L, respectively, and the pH value was 6.3-6.9, all meeting with Discharge Standard of Water Pollutants for Starch Industry (GB 25461-2010). The clean production renovation engineering could also create an annual economic benefit of 1.320 4 million Yuan.