Treatment Of Effluent Water From Bio-flocculation Adsorption Technology By Biological Aerated Filter (BAF)

It should be noticed that process of bio-flocculation and adsorption can remove most of the COD and SS from wastewater, biological aerated filter (BAF) is easy to block and requires less influent SS. Up-flow biological aerated filter(UBAF) filled with ceramics grain was used to treat the domestic sewage of campus discharged from the process of bio-flocculation and adsorption. The efficiency of the said system on pollutants removel, its anti-impact load capacity and the influence of dissolved oxygen and temperature on its treatment performance were investigated.Strarted the denitrification BAF based on the said examination,the nitrogen removel poformance without external carbon source was investigated. Simultaneously, this paper explored the nitrogen removel poformance when using sodium acetate and glucose as carbon resource at different C / N.Main results are as follows:1. The average effluent COD, NH₄⁺-N, SS of UBAF were 33mg/L, 5.7mg/L, 2.9mg/L, respectively, which could meet the sepecifacation for grade 1 level A in GB18918—2002 Discharge standard of pollutant for municipal wastewater treatment plant. But the average removal rate of TN was only 28%, the average effluent was 28mg/L.2. UBAF had a strong anti-shock loading capability,however,its nitrification performance was greatly affected by shock loading. When the hydraulic loading ranged from 0.6 m³/(m².h) to 1.8 m³/(m².h) ,the COD and SS removel by UBAF were slightly affected while the NH₄⁺-N removal was significant affected. The COD removal efficiency decreased slightly when the influent COD loading rate increased from 1.84 kg/(m³.d) to 5.6 kg/(m³.d). But the influent NH₄⁺-N loading rate increased from 0.49 kg/(m³.d) to 1.07 kg/(m³.d),its removal rate decrease obviously. The SS removal rate was stabilized above 90% almost unaffected when the SS influent SS loading rate ranged from 0.83 kg/(m³.d) to 2.45 kg/(m³.d).3. The removel efficiency of COD and SS by UBAF were slightly affected when the DO or temperature changed within a certain range while the NH₄⁺-N removal was significant affected. The removel rate of COD increased slowly when the DO ranged beween 2mg/L and 8mg/L and the removel rate of SS reached 94% which is the highest. When the DO ranged beween 2mg/L and 4mg/L, the removel rate of NH₄⁺-N was only 36%, but it reached 93% when the scope was 6⁸mg/L.The temperature fluctuated between 7oC and 28 oC during the experiment. The max effluent COD was 58mg/L and the minimum was 14mg/L. All the effluent SS were less than 5mg/L. However,the effluent NH₄⁺-N fluctuated significantly which reached the lowest 0.37mg/L at high temperature and reached up to 14.6mg/L at low temperature.4. There was low nitrogen removal rate(18%) without external carbon source and the effluent TN was 13³0mg/L. When using sodium acetate as carbon resource, the most appropriate C/N was 5.1 in which case the effluent TN and COD was less than 10mg/L and 50mg/L respectively and almost no nitrite accumulated. The most appropriate C/N is 6.9 when using glucose as carbon resource, the nitrite accumulation was more than sodium acetate under similar C/N and the removel velocity lagged relatively.