化学废水中重金属离子浓度软测量方法研究

为了降低废水重金属离子浓度测量误差，结合现有的研究理论，提出化学废水中重金属离子浓度软测量方法。采用电导率计和密度计组成可用于废水检测现场的检测装置，利用安装金属铁板的电解槽对化学废水进行电化学检测；通过电解液溶解氧化铁离子，生成吸附重金属离子的氢氧化铁，定量描述氢氧化铁絮体吸附能力，建立重金属离子浓度软测量模型；根据装置检测到的废水电导率、密度、温度，计算软测量模型待辨识的变量参数，确定离子浓度软测量值。将某化学废水处理厂作为研究对象，采集不同类型废水水样，把检测装置安装在废水排放出口，现场检测废水中的钴离子、铅离子、钨离子浓度。结果表明，3类重金属离子浓度软测量值和实际值的相对误差都小于14%，软测量精度较高。

Study on soft sensing method of heavy metal ion concentration in chemical wastewater

In order to reduce the measurement error of heavy metal ion concentration in wastewater，combined with the existing research theory，a soft measurement method of heavy metal ion concentration in chemical wastewater was proposed.The conductivity meter and densitometer were used to form a detection device that can be used for wastewater detection on site.The electrolytic cell installed with met al iron plate was used for electrochemical detection of chemical wastewater.Iron oxide ions were dissolved in the electrolyte to generate iron hydroxide adsorbing heavy metal ions.The adsorption capacity of iron hydroxide flocs was quantitatively described，and the soft sensing model of heavy metal ion concentration was established.According to the conductivity，density and temperature of wastewater detected by the device，calculate the variable parameters to be identified in the soft sensing model，and determine the soft sensing value of ion concentration.Taking a chemical wastewater treatment plant as the research object，collect different types of wastewater samples，install the detection device at the wastewater discharge outlet，and detect the concentrations of cobalt ions，lead ions and tungsten ions in the wastewater on site.The results showed that the relative error between the soft measured values and the actual values of the three types of heavy metal ions is less than 14%，and the soft measurement accuracy is high.