Industries during the manufacturing process generate a huge quantity of highly toxic effluents which yield discharges having very high BOD, COD, TS, and TDS level. The main objective of an effluent treatment plant is to process the effluent discharge and bring it under pollution control norms. There are multiple methods of effluent treatments done in the industry.
The evaporative treatment process is one of the major types that is used worldwide. It mainly includes evaporation in multiple effect evaporators, drying of concentrate, separation of solids by centrifuging or decanting, drying of wet solids to convert into powder. The process separates the water from the dry solids. The water can be recycled in the plant and the solids are either recycled back into the product or incinerated for heat generation or disposed of as solid effluent depending on its properties.
The evaporation process is driven by heat transferred from hot steam to a solution at a lower temperature across a metallic heat transfer surface. The absorbed heat causes vaporization of the solvent, usually water, and an increase in the solute concentration. The resulting vapor may be vented to the atmosphere, or condensed back to liquid for reuse.
As the main energy requirement is in the form of heat, at a temperature range of 100 – 150°C solar thermal concentrator systems like CST can easily supply heat within this temperature range using either steam or pressurized hot water. Schematic of the typical solar assisted effluent evaporation system is shown in the above figure.
Concentrated Solar technology CST generates steam or pressurized hot water at the required temperatures. The heat is transferred to evaporate the contents of the effluent tank, through heat exchanger coils. The heat can be stored in the heat storage tank to ensure continuous operation for effluent evaporation/treatment. To improve the effectiveness of the evaporation, various means can be used to augment the evaporation, for example, forced circulation of the hot air over the effluent. Clique Solar can design the complete solar assisted effluent evaporation system with very high efficiency and assure delivery guarantee.