Study On The Operation Characteristics Of High Concentration Rice Wine Wastewater By Modified ABR-anoxic Contact-CSTR Combination Process

Rice wine wastewater is a kind of high concentrated organic wastewater,in which there are many contaminants such as amino acid nitrogen,starch and sugar.Because of its higher B/C value of about 0.6,rice wine wastewater has a good biodegradability.The conventional treatment process has a good effect on decarbonization.However,the different brewing technologies of rice wine can cause the different quality of wastewater,especially the difference of the content of amino acid nitrogen,which brings a low removal efficiency of nitrogen and phosphorus.Therefore,it is necessary to develop new technology to improve the removal efficiency of nitrogen and phosphorus.In this paper,the yellow rice wine wastewater was treated by a combined process called "improved ABR-anoxic contact-CSTR",which was added suspended filler in the ABR segment.The effect of COD volume load on combined process was discussed,and the removal efficiency of nitrogen and phosphorus in wastewater under different reflux ratio and reflux sites were investigated and optimized.Main conclusions are as follows:?1?At a temperature of 35±2? and reflux ratio of 100%,volume load increased from 2 to 9 Kg COD·m^-3·d^-1,the average effluent concentration of COD,NH₄⁺-N,TN and TP wererespectively 122,0.9,38 and 1.2mg·L-1,the average removal rates were 98%,98%,53% and 78%,Under the circumstances,the combined process has a good effect treatment ofricewine wastewater.?2?With volume loading increasing from 2 to 9 Kg COD·m^-3·d^-1,the COD removal rate decreased from 90% to 66%,and the effluent concentration of COD was increased from 41 to 265 mg·L-1.The increase of volume load has effect on the system treatment efficiency,but the average removal rate of COD is still above 98%,which reflects the impact of the system on the organic load.The interception function of suspended filler ensures the SRT of ABR.It is the guarantee of high efficiency of decarbonization.?3?When the volume load is 2⁶ Kg COD·m^-3·d^-1,the front compartment is mainly producing acid bacteria,the dominant bacteria in the back the compartment were methane producing bacteria.When the volume load up to 9 Kg COD·m^-3·d^-1,VFA in the front compartment is excessively accumulated,having the tendency of slight acidification.Therefore,if we want to maintain the high efficiency and stability of the combined process,the volume load should not exceed 6 Kg COD·m^-3·d^-1.Among them,a large amount of propionate accumulation is the cause of the ABR segment to reduce the efficiency of decarbonization.?4?With the HRT of 32 h,SRT of 12 h,DO of 2 mg·L-1,reflux ratio of 300% and reflux site in the fourth compartment,combined process obtained the optimal conditions.Average removal rate of COD,NH₄⁺-N,TN and TP respectivelywere99%,99%,81% and 79%,and while the effluent concentration of COD,NH₄⁺-N,TN and TP were71.2,0.54,14.7 and 1.37 mg·L-1respectively.