Study on refinement of used water in laver and CO2 gas pumps of sugar plants Using liming

One of the most important stages in sugar industry that making wastewater and contamination is the water obtained to washing of CO2 in mazoot furnace and related pumps. Amount of water consumption in this stage is about 30 to 35 percent of weight of sugar beet, so amount of this stream is considerable. Mixing of carbon black and water compose the colloid in liquid phase. These colloids do not separate easily. This water is black, thus it is unuseable. In this study used liming to refining of wastewater. Samples obtained from tow factories (sugar plant of torbat heydariyeh and joveyn). Lime was added into samples directly. Relationship of pH to amount of added liming, rate of deposition of carbon black, volume of mud and coagulation percent was investigated. the results shown that there is a strong correlation between amount of lime milk and given parameters and rate of deposition of carbon black, volume of mud and coagulation percent evaluate with obtained equations. Additionally the results shown that carbon black separate completely in pH = 11.65, and obtain glassy water.