Study On Citric Acid Waste Water Treatment With UASB Launched By Dewatered Aerobic Sludge

Every year,China discharges a large amount of high consistency citric acid waste water,which seriously polluted natural environment。With the new standards of citric acid industry and the demands of energy-saving and ejection-decreasing,citric acid industry faces a more and more heavier environmental pressure.This study treated citric acid waste water by UASB which inoculated and launched by dehydrated aerobic sludge,discussed its possibility,and raised volumetric load step by step at high temperature(55℃)å'Œmedium temperature(35℃). This article also analyzed the characters and influence factors of the UASB,and contrasted the treatment effects of the UASB at high and medium temperature.The experiment showed that,at the launch stage,the removal rate wasn't steady,the UASB anti-strike load was weak,so the input consistency shouldn't be too high. The UASB launched at a volumetric load lower than 1 kg/(m~3·d), and raised the volumetric load after the removal rate became steadier and higher.The further experiment showed that,in high temperature(55℃) reactor,under the condition of 24h-HTR,the UASB entered waste water 3L/d, the volumetric load was raised step by step. After 82days cultivating and taming,the volumetric load finally reached 9.5 kg/(m~3·d),and the removal rate reached 80%~85%. Under the same condition in medium temperature(35℃),the UASB removal rate finally reached 85%,and the volumetric load reached 9.4 kg/(m~3·d),and the outlet VFA was 3.2mmol/L.At the beginning of the launch,the load of medium temperature reactor was raised quicker than that of high temperature reactor,the removal rate was also better. After 82days cultivating and taming,the removal rate of the medium and high temperature reactors reached above 80%. So to the high temperature waste water discharged from citric acid factory,the high temperature treatment could reduce the invested cost,and has good economical value.