Study Of Resource Utilization Of Remanent Activated Sludge

The task is mainly about resource utilization of remanent activated sludge. In the craftwork of activated sludge process, remanent activated sludge is part of activated sludge which is removed after secondary precipitating tank. Its main component is a mass of microorganism with biologic activity, which makes it have flocculating activity—adsorption and sedimentation. Thereout, the idea that using remanent activated sludge to produce microbial flocculants with the more superior performance is come into being.Remanent activated sludge has flocculating activity, which has relation to chemical component and apparent charge of microbial cell in it. Moreover, the apparent charge of the cell has direct ratio with its zeta-potential. The article researched the effect of acid, alkali and chemical disinfector on the surface of bacteria in remanent activated sludge, especially the zeta-potential. And conjecture the sterilizing mechanism of chemical disinfector. The conclusion are as follows: (1) In acidic condition, the surface zeta-potential of bacterial cell is lower, namely its surface has less negative charge; (2) In alkaline condition, the surface zeta-potential of bacterial cell is higher, namely its surface has more negative charge. The reason is that the H⁺ and OH^- react with the chemical component in the structure of bacterial cell wall, which changes the charge sign of some activated groups like —OH, — COOH, —NH₂ in it. (3) Chemical disinfectors react with the activated groups in the cell wall by acylate, cross-link and oxidation reaction, which changes the character and charge sign of some activated groups. Therefore, the physiological function of cell wall is destroyed, which leads the cell to death.Then use this as experimental groundwork to study the flocculating activity of remanent activated sludge with quality changed by acid or alkali, and conjecture its flocculating mechanism. Come to a conclusion that the flocculating mechanism of remanent activated sludge has complexity, and that it is multifactor common function, mainly includes...