Study On Key Technologies Of High Salt Wastewater Zero Discharge

Zero discharge technology of high salt wastewater is the inevitable requirement for environmental protection,especially the high salt wastewater treatment part industry has seriously restricted the production and development of enterprises,is one of the high degree of attention to the current and future period of time at home and abroad.In this paper,the main influencing factors of the process of softening,soft acid exchange,softening,reverse osmosis concentration,forward osmosis and evaporation crystallization of Handan Thermal Power Plant were studied,determine the relevant technical parameters for engineering applications to provide technical support.The results showed that the best dosage of Ca?OH?₂ was 700mg/L,Na₂CO₃ was800mg/L.the removal rate was 90%;Further softening of high saline chemicals after softening with D113--?type weak acid cation resin,Ca²⁺,Mg²⁺ all have been absorbed into the equilibrium concentration of the adsorption capacity of D113--?type resin for Ca²⁺,Mg²⁺ for 114000mg/L;By using reverse osmosis,the concentration of salt in the water tank was increased with the increase of salt content in the raw water tank.The concentration multiple is 2.32 times.Experimental study on the performance of reverse osmosis test concentrated water by using a self-made positive osmosis membrane.Learn the effect of concentration on membrane performance: with the increased concentration of the draw,this experiment used the water flux of forward osmosis membrane also increased with the increase of water flux from 5.3L/?m²·h?up to 23.1L/?m²·h?;and the salt concentration decreased with the increase rate of draw will slow,salt rejection decreased from 94.2% to 93.8%;the reverse salt flux will increase,by 3.5g/?m²·h?up to 14.9g/?m²·h?.No effect on special reverse salt flux.Effect of temperature on membrane performance: as the temperature rises slowly,membrane flux increased,the temperature reached 35 degrees,the maximum water flux of 14.9 L/?m²·h?,the retentate rate would be slightly decreased,reverse salt flux will increase with the increase of temperature,at 30 degrees and the reverse salt flux reaches the maximum value of 11.3g/?m²·h?,and then decreased with temperature increasing.Effect on special reverse salt flux.The 4040 type is found with Saehan penetration roll film experiment,with forward osmosis test,permeability test device operation,raw liquid conductivity first increases slowly increases rapidly,finally tends to be stable.When the concentration of is 1mol/L,the conductivity of the raw material can be concentrated to 43800?S/cm,The concentration can be up to 6 times;When the concentration of the solution is2mol/L,the conductivity of the raw material can be concentrated to 69300?S/cm.The concentration can be up to 9.5 times.The water flux decreases gradually,and finally approaches zero.Three methods were used to compare the recovery and purification of the extract by column distillation,blow up distillation and vacuum distillation,No matter from the recovery or purification of water,the method of blowing distillation and vacuum distillation is better than the column distillation method.Temperature control at 50 to60 ?,the recovery rate of the two methods can reach more than 60%.The temperature is controlled between 65 and 75? when evaporating and crystallizing the concentrated brine containing sodium chloride and sodium sulfate,which is beneficial to the purification of sodium chloride and sodium sulfate.