Removal Of Industrial Wastewater Containing Barium With Electrodeposition-biofilm

Wastewater containing heavy metals do serious harm to the environment,therefore,Foreign scholars have carried out active research on treatment of this kind of wastewater. Based on the experimental study on treatment of wastewater existing single heavy metal ion,electric biofilm method was used to remove the actual organic wastewater containing Ba²⁺.Microelectrolysis absorption and adsorption of heavy metal ions from wastewater biological advantages compound the process of wastewater treatment.Firstly, impact factors on removal efficiency of COD and Ba²⁺ were studied in this paper. Also we compared electric biofilm compound technology with the single biofilm technology.Under aerobic conditions, COD was degraded from 400-600 kg/d to 2500-4000 kg/d by using the single biofilm treatment method. Ba²⁺ concentration was decreased from about 20kg/d to 10kg/d. The effect of temperature, pH value and flowrate on removal efficiency of COD and Ba²⁺ was obtained by analyzing industrial data of single biofilm technology. It has bad effect on operation with temperature too high or too low. Biofilm activity is at its best temperature under 34℃, and Ba²⁺ and COD have the highest removal efficiency. Inceasing pH value can enhance the removal of Ba²⁺, but hinder the removal of COD. This is because the adsorption process of Ba²⁺is a fast process and will not be effected by flowrate. However, with the increased flowrate, the romoval efficiency of COD is decreased.The effect of degradation of organic compound and to removal fo heavy metal ions is obvious by electric biofilm compound technology. Compared with single biofilm technology, the removal efficiency of Ba²⁺ was increased 10%. Invastigating the effect of electrode spacing on removal efficiency, results show that the small spacing is not good for the bio-reaction, but can improve the removal of Ba²⁺. In order to chose the best space, we have to consider the both effects.Using a stainless steel plate as cathode,and grapHite as anode,the following optimal wastewater treatment conditions are determined by experiments. temperature 34°C,pH 9.0 and flowrate 959m³/d. With electrode spacing of 30cm, area of 30×20cm² and 2V voltage,and the same flowrate and velocity, the efficiencies of Ba²⁺ and COD are 84.91% and 54.67% respectively.