Um modelo para automa??o de Esta??o de Tratamento de Efluentes

摘要

Population growth and intensification of industrial activities have increased?the deterioration of natural resources. Industrial, hospital and residential wastes are?dumped directly into landfills without processing, polluting soils. This action will have?consequences later, because the liquid substance resulting from the putrefaction of?organic material plows into the soil to reach water bodies. Cities arise without planning,?industrial and household wastes are discharged into rivers, lakes and oceans without?proper treatment, affecting water resources. It is well known that in the next century?there will be fierce competition for fresh water on the planet, probably due to the scarcity?of it. Demographic expansion has occurred without proper health planning, degrading?oceans, lakes and rivers. Thus, a large percentage of world population suffers from diseases?related to water pollution. Accordingly, it can be concluded that sewage treatment is?essential to human survival, to preserve rivers, lakes and oceans. An Effluent Treatment?Plant (ETP) treats wastewater to reduce its pollution to acceptable levels before sending?them to the oceans or rivers. To automate the operation of an ETP, motors, sensors?and logic blocks, timers and counters are needed. These functions are achieved with?programmable logic controllers (PLC) and Supervisory Systems. The Ladder language is?used to program controllers and is a pillar of the Automation and Control Engineering.?The supervisory systems allow process information to be monitored, while the PLC are?responsible for control and data acquisition. In the age we live in, process automation?is used in an increasing scale in order to provide higher quality, raise productivity and?improve the proposed activities. Therefore, an automatic ETP will improve performance?and efficiency to handle large volumes of sewage. Considering the growing importance of?environmental awareness with special emphasis on the conservation of water resources,?this paper aims to propose an automation model of an Effluent Treatment Plant, using?Ladder programming language and supervisory systems.