竹炭固定化微生物对土壤中阿特拉津的降解研究

采用环境友好材料竹炭为主要载体,壳聚糖和海藻酸钠为辅助载体,固定从污泥中分离出的阿特拉津降解菌株,研究不同固定材料对降解菌生长的影响,以及固定化微生物对土壤中阿特拉津的降解效果.结果表明,竹炭对阿特拉津降解菌具有较强的吸附固定能力,且竹炭粒径越小,固定化效果越好.利用壳聚糖和海藻酸钠交联并加固阿特拉津降解菌,增大了固定化空间,显著增加了降解菌的生物量,并提高了阿特拉津的降解效率.1％壳聚糖+5％海藻酸钠+竹炭+降解菌颗粒对阿特拉津降解菌的固定化效果最佳,施用该微生物固定化颗粒28天后,砂姜黑土及红壤中阿特拉津残留率分别为48.07％和47.23％.

Biodegradation of atrazine in soils by bamboo charcoal immobilized a degradation bacterium

Bamboo charcoal was selected as the principal carrier, and chitosan and sodium alginate as the secondary carrier for the immobilization a degradation bacterium which was isolated from activated sludge. The growth of immobilized microorganism on bamboo charcoal and atrazine degradation in soils were investigated. The results showed that bamboo charcoal had a large capacity of immobilized microorganism. The smaller the particle size of bamboo charcoal, the more the microorganism immobilized. The strains grew well on bamboo charcoal, and reached logarithmic phase at 48 h. Chitosan and sodium alginate were used for cross-linking microorganism on bamboo-charcoal, which enlarged the space for the cell growth, significantly increased the biomass of bacterium. 1% chitosan + 5% sodium alginate + bamboo charcoal were suggested for the optimum formulations of microorganism immobilization. The degradation rate of atrazine in soil was larger significantly when adding immobilized microorganism by bamboo charcoal. After 28 d, the residues of atrazine in vertisol and red soil were 48.07% and 47.23%, respectively.