What are the technological characteristics of zero discharge of coal chemical wastewater-Ocpuritech

What are the technological characteristics of zero discharge of coal chemical wastewater?

by:Ocpuritech     2021-03-29
What are the technological characteristics of zero discharge of coal chemical wastewater? Author of the article: current domestic coal chemical industry mainly uses the waste water evaporation, flue treatment method treatment, but after precipitation into treatment compliance, wastewater still contains high concentrations of dissolved solids, etc., is difficult to reuse, in general, direct Disposal method of discharge. It not only wastes water resources, but also changes the physical and chemical properties of soil and water bodies. 1. Evaporation method Evaporation method is one of the commonly used methods in zero-discharge wastewater treatment. Its principle is: the wastewater entering the evaporator is heated to boiling by steam or electric heater, the water in the wastewater gradually evaporates into water vapor, and the water vapor is cooled After it is condensed into water and reused, the soluble solids in the wastewater are trapped in the distilled liquid, and as the concentration ratio increases, they precipitate out in the form of crystals. However, the evaporation method has the disadvantages of high energy consumption, easy fouling of equipment and large investment, which is also an important factor restricting its application. Therefore, in order to reduce the cost of zero-discharge treatment and ensure the normal operation of the system, it is necessary to pre-treat wastewater from the aspects of wastewater reduction and anti-scaling treatment. For example, the wastewater enters the high-pressure reverse osmosis (DTRO) pre-concentration system before it enters the evaporator to concentrate, and the mass concentration of the desulfurization wastewater TDS is pre-concentrated from 25-40g/L to 80-100g/L, reducing the amount of water entering the evaporator system and improving operation efficiency . 2. Flue treatment method: When the flue evaporation method is used to treat desulfurization wastewater, a certain spray method is first used to atomize the desulfurization wastewater and spray it into the flue before the electrostatic precipitator. The wastewater is heated by high-temperature flue gas in the form of small droplets. After evaporating and gasifying quickly, the suspended solids and soluble solids form fine solid particles, which then enter the electrostatic precipitator under the entrainment effect of the airflow and are captured and removed by the electrode, realizing near-zero discharge of desulfurized wastewater. It is worth noting that adding appropriate chemicals to the desulfurization wastewater and then performing the flue evaporation treatment can also have a synergistic effect and promote the removal of other pollutants in the flue gas. Not only can the zero discharge treatment of wastewater be realized, but also the removal efficiency of PM2.5 in the flue gas can be effectively improved, and the dust removal efficiency of the process can be increased by 37%. The flue evaporation treatment method has simple operation and low operating cost, but the flue treatment method cannot recover water resources, and there are still a large number of potential effects that cannot be determined.
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