The Treatment Of Citric Acid Wastewater

China is the largest country of citric acid production and exportation. but the fixed characteristic of 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. Several wastewater treatment technologies of citric acid are presented, such as the feeding stuf yeast production, upflow anaerobic sludge bed process, activated—sludge process, photosynthetic bacteria process, emulsion liquid membrane process and comprehensive treatment process. In addition, a simple comparison of the principles and technical flow of different technologies is also made.This experiment after passes through the UASB reactor processing citric acid waste water as the object of study, following good oxygen processing uses the SBR reactor, It presents the pH change for SBR Sequencing Batch Reactor used to treat citric acid Wastewater. The pH change of solution has relationship with the removal ratio of COD of citric acid wastewater. pH is a simple parameter for the treatment process controlling. The research result can provide the basic information for the purpose of realizing the treatment process control of SBR automatically.the experimental result indicated: in does not adjust pH the citric acid waste water to enter in the water, monitors in the SBR reactor the pH rule, may understand COD the degeneration degree, when pH tends to generally stably, also assumes the alkalinity, then indicated the degeneration effect is good. If in uses in the SBR law processing citric acid waste water, when reaction stage conclusion, intermixture pH still assumed the acidity, then might conclude COD the degeneration effect was not good. There is no influence on the degradation effect if the pH of raw wastewater is between 3—10. but keeping pH 7—8 can shorten the reaction time. when the citric acid concentration (COD< 500 mg/L) is low , uses 8 h operating mode to be possible to achieve 90% above elimination rate, along with the lemon acid concentration increase, COD surpasses when 500 mg/L the reaction time needs to lengthen, uses 16 h operating mode comparison being suitable; compares high in the citric acid concentration (COD> 500 mg/L), uses the aeration to enter the square water pitcher type to stir the water and instantaneous enters the water to be more advantageous than in the reduction operating time aspect; when COD of citric acid wastewater is between 500—2500 mg / L. the 16 hour operation mode and aeration filling can be used. the max ratio of degradation can reach more than 90% . The turbidity of effluent is related to the property of activated sludge.