CAST-MBBR及SF-AO工艺在污水处理中的应用比较

某污水处理厂一期工程规模为10×10^4m^3/d,采用CAST工艺,出水水质执行一级B排放标准,提标扩建工程规模为25×10^4m^3/d,出水水质提高至一级A标准。对一期工程,通过投加填料形成CAST-MBBR系统,并调整运行周期、投加碳源、一二期出水混合、增加三级处理;另外,新建15×10^4m^3/d二期工程,二级处理选用节地、节能、集约化的多级AO工艺。一、二期工程出水一并进入新建的三级处理系统中,选用高负荷、节地、出水水质好的"CoMag磁混凝澄清+纤维转盘过滤"工艺。工程总占地面积为5. 64 hm^2(折合单位占地为0. 226 m^2/m^3),项目总投资为39 558. 88万元,污水处理成本为1. 28元/m^3。实际运行效果表明,出水水质优于一级A标准。其中,CAST-MBBR对有机物、SS的去除效果好于SF-AO,而SF-AO对氨氮、总氮的去除效果及稳定性优于CAST-MBBR,总磷去除效果两者基本相当。CoMag出水SS稳定在5 mg/L以下,出水TP稳定在0. 1 mg/L以下,工程效果达到并超过了预期。

Application and Comparison of CAST-MBBR & SF-AO Process in Municipal Wastewater Treatment

The scale of the phase Ⅰ project of a sewage treatment plant was 10 × 104 m3/d. The effluent quality was carried out according to the first grade B discharge standard by the CAST process.The scale of the upgrading project was 25 × 104 m3/d,and the effluent water quality was raised to first grade A standard. The original CAST of phase Ⅰ was alternated to CAST-MBBR system by addition of suspended biological fillers. Then,the operating cycle was regulated,carbon source was added,the phase Ⅰ and phase Ⅱ effluents were mixed,add tertiary treatment stage was adopted to improve the treatment performance. The secondary treatment of phase Ⅱ(new construction 15 × 104 m3/d) adopted the technology of "SF-AO",which was land saving,energy saving and intensive. The new three-stage treatment (25 × 104 m3/d for phase Ⅰ and Ⅱ) adopted the CoMag magnetic coagulation clarification +fiber rotary table filtration process with high load,land saving and good effluent quality. Project scale was 25 × 104 m3/d,land use area was about 5. 64 hm2 (equivalent to 0. 226 m2/m3),total investment of the project was about 396 million yuan,treatment cost of wastewater was 1. 28 yuan/m3. The actual operation results showed that the effluent was superior to the first grade A standard. CAST-MBBR had a better removal effect on organics and SS than SF-AO,while SF-AO had a better removal effect and stability on NH4+-N and TN than CAST-MBBR,and TP removal rate was basically similar. The effluent SS of CoMag was stable below 5 mg/L,and effluent TP was stable below 0. 1 mg/L,and the project had achieved and exceeded expectations.