Investigation On Desalination And Incineration In Fluidized Bed For Organic Salty Liquid Wastes

Great deals of organic salty liquid wastes are discharged by industries of chemical engineering, pharmacy and paper making, which are easy to lead irreversible environmental pollution. High concentration organic liquid wastes cannot be disposed effectively by routine treatment methods. Incineration is a very potential method for disposal of these liquid wastes. However, low-melting point alkali metal and alkaline-earth metal salts bring the problems of agglomeration, fouling, sintering and defluidization during incineration. So, development and study of organic salty liquid wastes is strigent need in this field.A new wastewater incineration system with evaporation-desalination pretreatment equipment was put forward to treat organic salty liquid wastes in this dissertation. Volatilization of VOCs(volatile organic compounds) and SVOCs(semi-volatile organic compounds) and desalination were analyzed roundly. Analysis of ion chromatography and COD(chemical oxygen demand) was discussed. Extraction for dedalination of evaporation residues and incineration of desalinated organic steam were also studied. In addition, kinetics of evaporation and combustion reactions were investigated.An ion chromatographic method for the determination of alkali and alkaline-earth metal cations in high concentration organic wastewater was developed. The separation of cations was achieved on an IonPac CS12A column with 20 mmol/L methanesulfonic acid as the eluent. The detection was performed by a conductivity detector. Na⁺, K⁺, Mg²⁺ and Ca²⁺ could be identified within 14 minutes. A C18 cleanup column was used for direct sample injection. The method is sensitive, selective, and simple, which is convenient to be used for determination of cations in the samples in the incineration of liquid wastes. Determination of COD in these organic liquid wastes is dominant for design of burner and estimation of incineration efficiency. High-speed catalytic method for organic liquid with high concentration of chloride ion and organic compounds was presented in this dissertation. Relative error is 0.15%～5.8% when the concentration of CY is 20,000～60,000mg/L. Accuracy of the method is good, the relative error is less than 2% and the recovery is 98%～102%. There is no "prominent difference" between standard method and high-speed catalytic method.Simulated phenol liquid wastes containing sodium chloride was evaporated and concentrated and sodium chloride was crystallized in different parameters. The experimental results showed that the higher initial concentration of sodium chloride increases the ratio of volatilization of VOCs and SVOCs, which is due to the effect of "salting out". When evaporation speed was increased from 1.67 ml/min to 2.73 ml/min, the total removal coefficient of sodium chloride was about 99.88%～99.99%. When the ratio of evaporation was 0.97, the efficiency of removal of NaCl, Na₂SO₄, and Na₂CO₃ was higher than 99.0%; while, the efficiency of removal of KCl was lower due to high mechanical and selective schlepp in vapour. The efficiency could be improved by reducing the ratio of evaporation or increasing the concentration of KCl. Volatile organic compounds had high ratio of volatilization when the pH of the wastewater was neutral and acidic. The volatilization ratio of organic compounds is affected by initial content of phenol, NaCl and evaporation velocity.Evaporation residues contain high concentration inorganic salts and non-volatile organic compounds, which can be incinerated after desalination. Simulated para-nitrophenol (PNP) liquid...