| The technology of industrial wastewater treatment monitoring in our country is in a stateof relatively backward and the literatures about the papermaking wastewater treatmentmonitoring system is quite a few, so it’s necessary to reinforce this study. All kinds of singleintelligent control have defects, integration control technology of several intelligent control orintelligent combined with traditional control will be applied widely and design theexploitation of dissolved oxygen control strategy. Based on this ideology, the dissolvedoxygen control strategies of papermaking wastewater process were designed and a pilotpapermaking wastewater treatment monitoring system has been developed.According to the actual SBR papermaking wastewater treatment process, a pilotpapermaking wastewater treatment monitoring system was developed with Kingview6.53and Siemens S7-200. The monitoring system can achieve all kinds of control performance ofSBR process, it contains the controlling of switches, pumps and reaction process, on-linemonitoring of DO value, pH value, ORP value and level, as well as the controlling of DOvalue and the level in the reaction process. Moreover, this monitoring system has functions ofprocess simulation shows, data record, equipment fault alarming and so on.After analyzing the monitoring system, a program of quick fuzzy control query table wasdesigned with Matlab2011b. And then, DO fuzzy controller with Siemens S7-200wasdeveloped by this program. Two novel control strategies have been put forward in the study:On/off fuzzy control strategy and compound fuzzy control strategy. Five control strategies forwastewater dissolved oxygen have been implemented: On/off control, PID control, fuzzycontrol, On/off-fuzzy control and compound fuzzy control. In the design process ofOn/off-fuzzy control and compound fuzzy control, fuzzy control query table was partition andoptimizing reconstruction in order to improve the control accuracy.In order to test the practical control effects of experimental papermaking wastewatertreatment automatic monitoring system, this system has been applied successively to thesynthetic wastewater treatment process and the papermaking wastewater treatment process.The control results were that, compound fuzzy control demonstrated best to the dissolvedoxygen of synthetic sewage, while on/off-fuzzy control performed best to the dissolvedoxygen of papermaking sewage. The results showed that the improvement integration offuzzy controls were suited to the papermaking wastewater and have a broad prospectapplication. On the other hand, the pilot paper mill plant automatic monitoring system had thecapacity of monitoring and controlling the papermaking wastewater treatment. |
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