Automation of Water Production Why the Modernization of Water Production Plants is Necessary
Water –Although seemingly available in abundancy - is a depleting ressource. Endress+Hauser (India) has carried a case study at Bauda water treatment plant, that indicates where the challenges and opportunities of tomorrow's water treatment system lie...
Water production has followed the same basic method for several decades even though the source of the water can be various. The water may be drawn from a lake, a river, subterranean aquifers or simple boreholes. It varies from close to brackish from boreholes up to clear mountain streams where it can be consumed immediately. Consequently some plants are equipped with complex treatment process and some have just simple sedimentation and disinfection processes.
If the source of the water is groundwater, dissolved impurities are likely to be present. These arise from the local soil chemistry and some of the impurities can be the salts of calcium, iron, magnesium, manganese and sodium plus nitrates, arsenic and fluorides. Calcium and magnesium salts affect the hardness, sodium salts cause scaling and corrosion problems in pipes and plant equipment, fluorides can enhance tooth resistance to decay but can also cause bone fluorosis and arsenic is a poison.
Water Treatment Plants, Tailored for Local Needs
Plant designs, therefore, vary based on local conditions and several different treatment processes have been developed. These include aeration, mixing, flocculation, filtration and disinfection processes. The design and complexity of any plant is therefore very much chemistry and local condition driven, but even within the many variations there is a basic overall scheme.
The source water is usually blended with chemicals in mixers and flocculators. These ensure that any microparticles that may be present can be coagulated, enabling easier sedimentation and separation later in the treatment. Once the primary treatment is done the water passes into sedimentation tanks where primary clarification takes place.