多晶硅生产废水回用处理工程实例

Project example of treatment of wastewater from polycrystalline silicon production for reutilization

针对多晶硅生产废水的水质特点,及回用水对总溶解固体和氟离子浓度要求较高的情况,江苏省某企业设计采用了AO生化-絮凝沉淀-超滤-反渗透组合工艺进行处理回用,工程设计规模为1万t/d。工程运行结果表明,在进水COD_(Cr)、NH_3-N、NO_3^--N、TDS、F-的质量浓度分别为570.6、4.30、34.20、4 737.5、21.90 mg/L时,出水COD_(Cr)、NH_3-N、NO_3^--N、TDS、F-的质量浓度分别为37.0、0.09、0.34、108.0、0.39 mg/L,出水水质满足GB/T 19923—2005《城市污水再生利用工业用水水质》中的工艺与产品用水标准,同时F-的质量浓度在0.5 mg/L以下,完全达到企业的回用要求。介绍了工艺流程和各构筑物的主要设计参数。

In view of the characteristics of wastewater from polycrystalline silicon production, and consider-ing the strict requirement of wastewater reutilization about total dissolved solids（TDS） and fluorinion concentra-tions AO biochemical-flocculation sedimentation-ultrafiltration-reverse osmosis combined process was adopted by a company in Jiangsu province for the treatment and reuse of the said kind of wastewater, the engineering de-sign scale was 10 000 t/d. The running result of the project showed that, when the mass concentrations of CODCr, NH3-N, NO3--N, TDS, F-of the influent water were 570.6、 4.30、 34.20、 4 737.5 and 21.90 mg/L respectively, the corresponding indexes of the effluent water were 37.0、 0.09、 0.34、 108.0 and 0.39 mg/L respectively, the effluent water quality met the requirement of water quality standard for craft and product in GB/T 19923-2005 The Reuse of Urban Recycling Water―Water Quality Standard for Industrial Uses. Besides, the mass concentra-tion of F-was lower than 0.5 mg/L, which totally met the demand of reuse water quality for the company. In addi-tion, the process flow and the main design parameters of structures were also introduced.