乡镇污水处理厂CASS工艺模型验证分析

Analysis of Model Validation for CASS Process in Township Wastewater Treatment Plant

按照某污水处理厂工程可行性研究的工艺比选意见采用CASS工艺。采用GPS-X软件对该工艺进行建模。在设计阶段,污水组分特征待定,采用软件中的默认组分值进行模拟。由模拟可知,在给定的设计参数下,该工艺能稳定运行,COD、TP、TN等出水指标达到设计要求。在旱季条件下,出水TN指标优于设计工况,TP指标较高,但仍低于一级B排放标准,对出水添加药剂进行化学除磷仍是必要的备用措施。在雨季1.5倍流量的条件下,模拟结果显示出水指标达到排放要求。在雨季条件下,模型默认的fss值(溶解基质/最终BOD)比实际值高,造成模拟条件下出水COD较高,模拟情况偏于保守,故为了修正结果,应进一步测定fss值。

According to the feasibility study of the project on process selection of a wastewater treatment plant, CASS process was adopted and software of GPS - X was used to set up the process model. At design stage,the wastewater component characteristics were unknown, so the default values were used for simulation. According to the simulation results, the process could run steadily using given design parameters and indexes of C0D, TP and TN in effluent could reach requirements. Under dry season condition, TN in effluent was lower than under the design condition. While TP was higher, i t was still below the national standard of f irst grade B. Adding chemical reagent for phosphorus removal was s t i l l a necessary backup. Under rainy season condition with 1.5 times of the design flow, indexes of the effluent reached the emission requirements. The default value of fss （dissolved substrate/final B0D ） under rainy season condition was higher than the actual one, causing a higher C0D in effluent. As a result, we should make further research on fss value to amend the result.