Design And Realization Of HDS-based Control System Of Industrial Waste Water Treatment

With the enhanced awareness of environmental protection, more and more attention is paid to the protection and management of environment. Domestic enterprises in industrial wastewater treatment process and technology has made considerable effort, also obtained many graceful performance. However, compared with the developed countries, there are still many gaps in the automation equipment of sewage treatment because domestic technology starts late. So Deepening of the automation equipment research in industrial sewage treatment has important and realistic significance.First, this paper introduces the domestic sewage treatment especially in industrial wastewater treatment process. It emphatically introduced the development state and problems of wastewater treatment control system which is the combination product of waste water treatment process optimization and automation technology.Secondly, according to the requirements of industrial wastewater treatment-HDS technological process, the automatic control system design which is based on bussing technique, consists of detection, automatic control, manual control, and remote control, was accomplished. The control system uses two level computer control mode. The basic automation level uses PLC of SIMATIC S7-300series to monitor the PHvalues of waste water, turbidity SS, level of calcium carbide milk tank and other process parameter, and it also can control the operating state of actuator on-line, such as aeration machine, Milk of lime opening valve, flocculant opening valve, and so on. The control level is Siemens industrial control computer which achieves the configuration, supervision, alarm, tabulation, and other system function.Aiming at the key technical issues, such as uneven PH of reaction tank, and strong interference when signals were transferred over long distance, the system introduced the agitation system of neutralization reaction, so as to make the entire reaction cell be in a relatively stable state. In addition, by mathematical statistical analysis of the deviation and relationship between measured values when PH meter was installed in different locations and the average PH values of the solution, reasonable installation location of PH meter was determined. And in order to eliminate the interference, the input to the model of the PH values collection should be grounded effectively. Through these measures, not only the unevenness of the PH was reduced, but also the normal working of the module and the accuracy of the collected signal were assured.The implementation of this project not only improves the industrial waste water treatment automation degree and labor productivity, but also favors the safety in production. The system runs stably and the control result is satisfying since put into operation and also reach the target that PH of the final effluent is6-9, which is completely in line with the two standard requirement in the national waste water discharge standard "GB8978-1996". It can avoid the pollution in the mining area and river when it misoperation or out of control, and it also achieved good economic and social benefit.