Study On The VOCs Emissions Of A~2O Wastewater Treatment System

In recent years, Fog haze weather becomes more frequent, Volatile Organic Compounds Volatile Organic (VOCs) has gradually been paid much attention. With the background of the research of A2O process in this paper,to explore the VOCs emission intensity of each processing unit in different operating conditions,for deepening the understanding on the VOCs emission intensity and the factors,which can provide special data basis for emissions of VOCs control and optimization in the Sewage treatment plant. The results prove that:Under normal operation condition, A2O process emissions is 0.323Kg every day per thousand tons sewage.anaerobic tank, anoxia tank, oxygen tank account for 14%、6%、80% separately. The result showed that aerobic aeration make VOCs escape into atmosphere from liquid easily. oxygen tank is the main unit of VOCs emission.The increase of concentration of organic matter would lead to the increase of VOCs emissions intensity. The result showed that:When the concentration of organic matter was 130 mg/L,225 mg/L,313 mg/L respectively,the A2O system VOCs emissions intensity was 0.999 ug/L.h,1.645 ug/L.h,1.819 ug/L.h. With the increase of concentration of organic, the growth rate of growth rate oxygen tank’s emission is biggest,the second is anaerobic tank, anoxia tank is the least.In aerobic aeration static test,with the increase of aeration fluxes the reactor rate increases and need shorter time to reach equilibrium and the rate of reduce of concentration of VOCs above the reaction becomes faster. But with the increase of air VOCs of whole reaction unit water increases. When aeration fluxes the reactor rate was 0.1 L/h,0.2L/h,0.3L/h, respectively,the aerobic aeration VOCs emissions intensity was 0.435ug/L.h,0.730 ug/L.h,1.090 ug/L.h. And the increase of aeration fluxes has a significant impact on VOCs emissions intensity,the higher Concentration of organic matter,the greater influence of VOCs emissions intensity.The impact of different hydraulic retention time has significant effect on VOCs emissions intensity of the process.The test results showed that:When the hydraulic retention time was 16.67 h,9.83h,12.29 h, respectively,the A2O system VOCs emissions intensity was 0.999 ug/L.h, 1.356 ug/L.h,1.533 ug/L.h.As the hydraulic retention time shortened, the VOCs emissions intensity increased. And has significant effect on each rector’s VOCs proportion of whole system. As the hydraulic retention time shorten, proportion of anaerobic tank’s VOCs emission reduce. anoxia tank also has a slight decline.but the proportion of oxygen tank has a significant growth.According to the factors and analysis of variance,the the significant of factors of VOCs emission intensity of A2O waste water treatment were aeration intensity> organic matter concentration>the water hydraulic retention time.