Removing Of Harm Ion In Waste Solution From Vacuum Potassium Carbonate Desulfurization

Vacuum potassium carbonate desulfurization and decyanation process is one kindof wet-type desulphurization methods. In this process, acidic gas from coke oven gassuch as hydrogen sulfide and hydrogen cyanide is removed with solution of potassiumcarbonate. Then coke oven gas will be washed with natronlauge for a second time.Drawbacks of this process are improved in this dissertation, and a proposal that wastesolution would be preprocessed with strong base anion exchange resin beforedischarging into the biochemical degradation pool is put forward.Waste solution is analysed with quantitative analysis methods firstly. There arehydroxyl, ammonium, sulfate radical, cyano complex, sulfur cyanogen root, sulfion,sulfite ion, carbonate and chloridion in the waste. With the help of theoretical analysisand production process of enterprise, that ammonium, sulfion, sulfur cyanogen root andchloridion will do harm to the biochemical degradation is affirmed, and concentration ofammonium, sulfion, sulfur cyanogen root and chloridion is3421.5mg/L,3546.0mg/L,3533.0mg/L,867.5mg/L and721.2mg/L respectively.When activated sludge dissolves in germ-free water, we make the solution intobacteria levitation liquid with the dilutability up to10~6. And bacteria levitation liquid willbe placed in culture medium to cultivate and reproduce. Then solution of target ion withsimilar concentration will be inoculated on the culture medium, and growth situation ofbacterial colonies should be observed. Experimental results show that ammonium is goodfor the growth of bacteria, and chloridion has no influence on bacteria, but sulfurcyanogens and sulfion are bad for bacteria. Because sulfion has a weak influence onbacteria, sulfur cyanogens are harmful ions which must be removed. When theconcentration of sulfur cyanogens is less than13.3mg/L, the inhibitory action issignificantly reduced. Therefore, the target of this experiment is to make theconcentration of sulfur cyanogens less than13.3mg/L.Four kinds of resin, such as201×7, D201, D261and D301, are taken to carry on theexperiment. Through the static adsorbable experiment, D261resin with the highestadsorption rate is chosen to conduct the experiment. The influence of resin volume,concentration of sulfur cyanogens, experimental temperature and rotation speed on adsorption capacity of D261resin is investigated. The experimental results show thatadsorption rate rises when the dosage of resin goes up. When the amount of resin is up to9ml, concentration of sulfur cyanogens in50ml solution which is3.55g/L dropped to13.2mg/L. So demands of this experiment are met. Aqueous ammonia with theconcentration of0.7mol/L is chosen as desorbing agent, and natronlauge is chosen asregeneration agent.