水体致黑硫离子高效氧化菌的固定化条件优化

Immobilization Conditions Optimization of Effective Bacteria for Blackening Sulfur Ion Oxidation in Water

S2-是导致城市河流水体变黑的主要污染物。该文开展了水体致黑硫离子高效氧化菌寡养单胞菌(Stenotrophomonas sp.)的固定化条件优化研究,分别考察了固定化初始p H、吸附时间、接种量及载体添加量这4个固定化过程中的主要因素对寡养单胞菌氧化黑臭水体中S2-的影响,以及对COD、NH3-N和TP去除的影响。实验结果表明,固定化初始pH、吸附时间、接种量以及载体添加量皆可显著影响寡养单胞菌对S2-的氧化率,以及对COD、NH3-N和TP的去除率。适宜的单因素条件分别为:固定化初始pH值8.0,吸附时间37.5 h,接种量5%和载体添加量1.0 g;在单因素实验条件下,S2-氧化率最高可达76.8%,COD、NH3-N和TP去除率最高可分别达到31.2%、60.7%和31.9%。在此基础上,响应面优化结果表明,最佳的固定化组合条件为:固定化初始pH值为8.1,吸附时间为37.4 h,菌体接种量为6.0%,人造沸石载体添加量为0.98 g。在上述最优条件下,S2-氧化率的预测值最高可达到82.4%,与实际值拟合率达到99%以上,较未固定化的菌体对S2-的氧化率提高了47.7%。

S2-is approved as the key blacking pollutant in a black-stinking water body.The immobilization experiment of effective bacteria(Stenotrophomonas sp.)for blackening sulfur ion oxidation was conducted in this study.The effects of initial immobilized pH,immobilized time,inoculation ratio and carrier additional amount on the treatment efficiency of a black-stinking water body were investigated,respectively.The experimental results showed that all of the investigated immobilization conditions including initial immobilized pH,immobilized time,inoculation ratio and carrier additional amount had a significant impact on the S2-oxidation ratio as well as the removal rates of COD,NH3-N and TP.The suitable conditions of each single factor were 8.0 of initial immobilized pH,37.5 h of immobilized time,5%of inoculation ratio and 1.0 g of carrier addition amount.Under single factor conditions,the maximal value of S2-oxidation rate could reach 76.8%,and the maximal removal rates of COD,NH3-N and TP were 31.2%,60.7%and 31.9%,respectively.Response surface methodology was then used to optimize the above immobilization conditions.The optimal immobilization conditions were 8.1 of initial immobilized pH,37.4 h of immobilized time,6.0%of inoculation ratio and 0.98 g of carrier addition amount;under which,the oxidation ratio of S2-increased by 47.7%compared with the unimmobilized strain and reached 82.4%.Furthermore,the fitting result between the model prediction and the experiment under the optimal conditions reached more than 99%,suggesting that the established polynomial regression model was feasible.