摘要：

为实现废水处理中脱氯剂投加的精准自控，通过对硫代硫酸钠脱氯效果的分析，构建了投药量DCM模型，进行模型非线性拟合，建立了污水脱氯投药自控系统。结果表明：水质净化厂进水余氯偏高时，污水中90%的余氯在与硫代硫酸钠反应起初1 min时就可被去除，脱氯效果主要取决于硫代硫酸钠投量；脱氯投药量DCM模型可用 \frac{C_t}{C_{\mathrm{0}}} = \frac{k_{\mathrm{2}}}{\mathrm{1}+k_{\mathrm{1}}{C}_R} + k_{\mathrm{3}}表示；DCM模型曲线和试验数据点相关性较好，拟合相关系数平方值都大于0.99，残差平方和都小于0.000 5，脱氯时间1 min时DCM模型拟合效果最好；基于DCM模型构建以可编程控制器为主体，以余氯在线监测仪为测量元件，以变频隔膜计量泵为执行设备的污水脱氯投药量自控系统，在厂区进水泵站集水井处投药，生物处理单元进水余氯值作为系统是否稳定正常运行的实时反馈。

关键词: 脱氯, 模型, 污水处理, 投药量, 硫代硫酸钠

Abstract:

The dechlorination effect of sodium thiosulfate and the DCM model for wastewater dechlorination were investigated in order to achieve the automatic control of the dosage of dechlorination agent. Meanwhile，the model calibration was carried out by the nonlinear fitting. The automatic control system of the dosage of dechlorination agent was also developed. The results showed that sodium thiosulfate could be used for dechlorination in the influent of a waste water treatment plant （WWTP），and 90% of residual chlorine in the sewage could be removed within one minute of the dechlorination reaction. The dichlorination efficiencies were mainly determined by the dosage of sodium thiosulfate. The DCM model could be described by \frac{C_t}{C_{\mathrm{0}}} = \frac{k_{\mathrm{2}}}{\mathrm{1}+k_{\mathrm{1}}{C}_R} + k_{\mathrm{3}}. The DCM model curves had a good correlation with the test data. The square values of the fitting correlation coefficients were greater than 0.99，and the residual sums of square were less than 0.000 5. The imitative effect of the DCM model was best while the dechlorination time was one minute. Meanwhile，according to the DCM model，the automatic control of the dosage of dechlorination agent was described with programmable logic controller（PLC） as the main controller，with the on-line monitoring instrument of residual chlorine as the measuring element and with diaphragm pump as the executive equipment. The dosing point was set at the water-collecting well of influent pump station of the WWTP. The residual chlorine values of the influent in biological treatment unit were used for real-time feedback to determine whether the automatic control system of wastewater dechlorination was running correctly or not.

Key words: dechlorination, model, wastewater treatment, dosage, sodium thiosulfate

中图分类号: 

• X705