C/N、DO和温度对SBBR高标准除磷脱氮效能的综合影响

以研发基于非工程措施的城镇污水高标准处理技术为目标，采用响应面分析方法，探究C/N、DO、温度等工艺参数对SBBR系统高标准除磷脱氮效能的综合影响。研究以C/N（A）、DO（B）和温度（C）为自变量，TN和PO₄3--P去除率为因变量，应用Box-Benhnken（BBD）试验设计方法，以及二次多项式模型，得出响应面方程:η（TN）=-70.76+7.58A+52.81B-0.36C+0.22AB-0.12AC+0.58BC-0.35A2-7.94B2+0.01C2，η（PO₄3--P）=-119.59+10.93A+72.91B+2.26C-1.50AB+0.05AC-0.13BC-0.33A2-6.86B2-0.07C2；ANOVA分析结果表明，DO和温度对系统除磷脱氮效能影响极显著，C/N对系统脱氮效能影响显著，其影响程度顺序为DO > 温度 > C/N，DO、温度对TN去除率的交互影响显著，C/N、DO对PO₄3--P去除率的交互影响显著；通过响应方程的构建，实现了系统参数与效能之间的量化，并通过试验验证了模型预测的最佳工况及其效能，研究结果可用于指导序批式生物膜高标准除磷脱氮系统参数的选择。在温度为23℃，C/N为9.5，DO为4 mg/L的条件下，SBBR系统的出水NH₄+-N、TN、PO₄3--P、COD浓度分别为3.9，5.0，0.4，40 mg/L，优于GB 18918-2002《城镇污水处理厂污染物排放标准》中一级A标准。

COMPREHENSIVE IMPACT OF CARBON TO NITROGEN RATIO,DISSOLVED OXYGEN AND TEMPERATURE ON ADVANCED PHOSPHORUS AND NITROGEN REMOVAL EFFICIENCIES IN SEQUENCING BATCH BIOFILM REACTOR (SBBR) SYSTEM

Comprehensive effect of carbon to nitrogen ratio (C/N), dissolved oxygen (DO) and temperature on phosphorus and nitrogen removal efficiency were identified using response surface methodology in a sequencing batch biofilm reactor (SBBR), aiming to develop high-standard urban sewage treatment technology based on the non-engineering measures. Total nitrogen (TN) and phosphate (PO₄3--P) removal rates were taken as the dependent variables, while C/N (A), DO (B) and temperature (C) were taken as independent variables. The Box-Benhnken (BBD) experimental design method and the quadratic polynomial model were applied. Results in response surface equations was illustrated as η(TN)=-70.76+7.58A+52.81B-0.36C+0.22AB-0.12AC+0.58BC-0.35A2-7.94B2+0.01C2, η(PO₄3--P)=-119.59+10.93A+72.91B+2.26C-1.50AB+0.05AC-0.13BC-0.33A2-6.86B2-0.07C2. Further analysis by ANOVA method proved that DO and temperature significantly affected both the phosphorus and the nitrogen removal rates whilst C/N had a remarkable effect on nitrogen removal efficiency. The impact degree of three parameters was DO, temperature and C/N, successively. The interaction of DO with temperature significantly affected the nitrogen removal rate. Moreover, PO₄3--P removal rate was obviously influenced by the interaction of C/N and DO. The quantifications of relation between operating parameters and system performance were achieved by the response equations, and the optimum working condition and efficiency of the model were verified by experiment, which could be used to guide the optimization of operating parameters in SBBR system for advanced phosphorus and nitrogen removal. The effluent NH₄+-N, TN, PO₄3--P and COD concentration of the SBBR were 3.9, 5.0, 0.4, 40 mg/L respectively, under the condition of temperature of 23℃, C/N of 9.5 and DO of 4 mg/L, which reached the high standard treatment better than Grade I-A standard in Discharge Standard of Pollutants for Municipal Wastewater Treatment Plant (GB 18918-2002).