Two acetate-fed sequencing batch reactors （SBR） were operated under an aerobic dynamic feeding （ADF） model （SBR#2） and with anaerobic phase before aerobic phase （SBR#1） to select mixed cultures with a high pol...Two acetate-fed sequencing batch reactors （SBR） were operated under an aerobic dynamic feeding （ADF） model （SBR#2） and with anaerobic phase before aerobic phase （SBR#1） to select mixed cultures with a high polyhydroxyalkanoates （PHA） storage response. Although kinetic selection based on storage response should bring about a predominance of floc-formers, a bulking sludge with storage response comparable to well-settled sludge was steadily established. An anaerobic phase was introduced before the aerobic phase in the ADF model to improve the sludge settleability （SBR #1）, however, due to the consequent increased feast/famine ratio, the performance of SBR #1, in terms of both the maximum PHB （polyhydroxybutyrate） cell content and APHB, was lower than that of SBR #2. SBR #2 gradually reached a steady state while SBR #1 failed suddenly after 50 days of operation. The maximum specific substrate uptake rate and storage rate for the selected bulking sludge were 0.4 Cmol Ae/（Cmol X.hr） and 0.18 Cmol Ac/（Cmol PHB.hr）, respectively, resulting a yield of 0.45 Cmol PHB/（Cmol Ae） in SBR #2 in the culture enrichment phase. A maximum PHB content of 53% of total suspended solids and PHB storage rate of 1.36 Cmol Ac/（Cmol PHB.hr） was achieved at 10.2 hr in batch accumulation tests under nitrogen starvation. The results indicated that it was feasible to utilize filamentous bacteria to accumulate PHA with a rate comparable to well-settled sludge, Furthermore, the lower dissolved oxygen demand of filamentous bacteria would save energy required for aeration in the culture enrichment stage.展开更多
基金support of the National Special S&T Project on the Treatment and Control of Water Pollution of China (No. 2008ZX07313-003)the Science Foundation of Harbin (No. 2007RFLXS013)+1 种基金the State Key Lab of Urban Water Resource and Environment at Harbin Institute of Technology (No. 2010DX02)the National Innovation Team supported by the National Science Foundation of China (No. 50821002)
文摘Two acetate-fed sequencing batch reactors （SBR） were operated under an aerobic dynamic feeding （ADF） model （SBR#2） and with anaerobic phase before aerobic phase （SBR#1） to select mixed cultures with a high polyhydroxyalkanoates （PHA） storage response. Although kinetic selection based on storage response should bring about a predominance of floc-formers, a bulking sludge with storage response comparable to well-settled sludge was steadily established. An anaerobic phase was introduced before the aerobic phase in the ADF model to improve the sludge settleability （SBR #1）, however, due to the consequent increased feast/famine ratio, the performance of SBR #1, in terms of both the maximum PHB （polyhydroxybutyrate） cell content and APHB, was lower than that of SBR #2. SBR #2 gradually reached a steady state while SBR #1 failed suddenly after 50 days of operation. The maximum specific substrate uptake rate and storage rate for the selected bulking sludge were 0.4 Cmol Ae/（Cmol X.hr） and 0.18 Cmol Ac/（Cmol PHB.hr）, respectively, resulting a yield of 0.45 Cmol PHB/（Cmol Ae） in SBR #2 in the culture enrichment phase. A maximum PHB content of 53% of total suspended solids and PHB storage rate of 1.36 Cmol Ac/（Cmol PHB.hr） was achieved at 10.2 hr in batch accumulation tests under nitrogen starvation. The results indicated that it was feasible to utilize filamentous bacteria to accumulate PHA with a rate comparable to well-settled sludge, Furthermore, the lower dissolved oxygen demand of filamentous bacteria would save energy required for aeration in the culture enrichment stage.
文摘通过对某污水处理厂循环活性污泥法工艺(cyclic activated sludge technology,CAST)中选择池、缺氧池和好氧池中氮组分和污泥浓度进行测定,结合污泥活性、同步硝化-反硝化(simultaneous nitrification and denitrification,SND)速率及饱食-饥饿(feast-famine)批次实验,评价该处理工艺的脱氮性能。结果表明,好氧池内同步硝化-反硝化和沉淀过程中的内源反硝化(endogenous denitrification,ED)脱氮对总氮去除的贡献占据主导,分别为(35.50±4.15)%和(62.86±4.13)%,而缺氧池反硝化(DEN)脱氮贡献仅为(1.64±0.05)%;溶解氧(dissolved oxygen,DO)浓度对CAST工艺脱氮性能有极大影响,控制好氧池中DO浓度为1~1.5 mg·L^(-1)时可获得最佳脱氮效果,CAST工艺的TN去除率可达84.51%;饱食-饥饿批次实验证明,饥饿时长为36 h时对乙酸(HAc)的吸收能力最强,可达每1 g VSS消耗0.173 g HAc,依此可推算出CAST工艺的最佳回流比为45%。
