Papers by Author: Yi Hua Yuan

Abstract: The effectiveness of the treatment to sewage water by using chitosan, sodium alginate and their complex as flocculating agent was investigated. It was discovered that parameters, such as pH value, temperature, speed and time of stirring, and setting time had direct relations with flocculants. Color/turbidity removing rate could be up to 90% with 15mgL-1 chitosan solution, while sodium alginate alone cannot act as flocculant since no floccules can be observed. Chitosan/sodium alginate complex flocculating agent was found to be an excellent coagulant which made a compliment with each other. The optimum dosage was 15mg L-1 chitosan plus 7.5mg L-1 sodium alginate for complex agent. The results of the orthogonal experiment showed that the optimum conditions to treating sewage water were 70°C for temperature, pH=5.5, fast stirring（600r/min or 900r/min） for 2min, plus slow stirring（100r/min or 300r/min） for 8min, and setting time 2.5h. In this case the chitosan/sodium alginate complex agent could achieve 100% color/turbidity removing rate and approximately 90.01% COD reducing rate.

Abstract: By using the chitosan and sodium alginate as raw material, (NH4)2Ce(NO3)6 as the initiator, under alkalinity condition, chitosan / sodium alginate copolymer was synthesized. Chemical structure of CTS-AGS was characterized by FT-IR, and the morphology of CTS-AGS was observed by SEM. The results showed the synthesis of CTS-AGS was carried out as the established way. The addition of AGS greatly reduced the hydrogen bonds and increased steric resistance among chitosan molecules, and hence made CTS-AGS had stronger affinity for water. The optimal conditions for the synthesis were: m(CTS)∶m(SAL) =2:1, reaction temp. is 70°C, and the best time is 24h.