污染物的迁移转化机理-英文版大作业资料.ppt

Important Mechanisms----Biodegradation Biodegradation is another important environmental process to degradation of styrene. In lakes, the high concentration of suspended solids provide good living environment to the heterotrophic bacteria. Research shows that most particles in the lake surface is rich covered by protein organic and protein of bacterial, forming a layer of organic film, this progress is very beneficial to degradation of styrene in lakes. Contents Introduction of Styrene Choice of Waterbody Physical and Chemical Properties Analysis of Mechanisms Input Mixing Calculation of Removal Rate Conclusion Determine the Input/mixing Condition Assume styrene discharge into the water in pulse form--- pulse input. 1 As the water contact with atmosphere, and with inlet and outlet for water to exchange, so it is open system. 2 Determine the Input/mixing Condition Determine the input/mixing condition for pollutant and waterbody: 4. The size of selected lake is small, sealing ability is strong, when styrene be poured into the lake, it will mix with lake water under the action of streams and wind power，then uniform mixing can be achieved. Therefore, the use of uniform hybrid water quality model is appropriate 3. The definition of point pollution is a point-like form of pollution discharge. As the common industrial chemicals, styrene usually has fixed sewage outfall to discharge, or due to leakage into water. Therefore, design point pollution as the pollution source. Design Condition Item Design Input Mode Pulse Input Type of Waterbody Open System Pollution Way Point Pollution Mixed Mode Perfect Mixing Detention Time: 0.7143 years Average Concentration: 0.3 mg/L Add Design Data: Table 4. Input/mixing Condition Contents Introduction of Styrene Choice of Waterbody Physical and Chemical Properties Analysis of Mechanisms Input Mixing Calculation of Removal Rate Conclusion Volatilization Overall Transfer Coefficient Liquid Phase Coefficient Gas Phase Coefficient Non-i