Study On Citric Acid Wastewater Treatment By Biochemical Method

Citric acid is a kind of important organic acid widely used for food and cosmetic industry. The citric acid production technology produces amounts of highly concentrated wastewater in the process, and becomes a serious source of environmental pollution. Therefore, it is crucial and urgent to treat the wastewater in citric acid industry. The production techniques and pollution process of citric acid are summarized based on the production process of citric acid. Several wastewater treatment technologies of citric acid are presented. In addition, a simple comparison of the principles and technical flow of different technologies is also made.The citric acid wastewater from production process is treated as the object and "UASB +contact oxidation" is chose as treated technics in this study. The feasibility study of these two treated technique are explored in this study. The factors of volume loading, pH of UASB influent and water quality of UASB effluent, which effect the removal of pollution, are slso investigated. The overall goal of this study is to find the best parameter to get higher removal. An example is used to analyzed the effect of citric acid wastewater with "UASB+contact oxidation".As to the research, it is feasible to treat the citric acid with "UASB+contact oxidation". After the field experiment of 91 days, the results gets the success. In the process of the experiment, It is feasible that the volume loading rate reaches the design loading rate 4-6kg/m3-d and even achieve 5.85kg/m3-d. The removal will be good when the wastewater is alkalescent. When the pH of the influent is in the range of 4-9, it have little influence on removal of COD. When the pH retained 7-8, the contacting time shortened. The outflow can reach the effluent standard after 12-16 h if the COD of influent keeps at 500-2500 mg/L...