以附着有生物膜的颗粒化有机粘土作为地下水修复中反应栅的反应载体,以柴油为对象,利用有机粘土对油料的吸附以及降解石油菌的协同机制,对石油烃污染水体进行了修复实验研究。通过正交试验获得了微生物降解柴油的最佳生长条件水平组合,即C:N:P为100:15:1,投菌量为15mL,氧化剂浓度为1%,初始pH为5。通过海藻酸钠(SA)与HDTMA改性的蒙脱土(HDTMA-modified montmorillonite。HMM)颗粒化制备,并复合石油烃降解菌,研究了不同质量比SA:HMM、不同SA浓度及CaCl2浓度下HMM颗粒的水稳性和吸油性、降解菌活性等性质。研究结果表明,在SA浓度为1%-2%,CaCl2浓度为2%-4%,SA:HMM=1:10时,获得的HMM颗粒粒径为2.5~4.0mm.对HMM表面结构影响不大,吸油率可达原始HMM的80%;将HMM颗粒与石油烃降解菌复合可形成稳定的生物膜,膜厚度为300μm左右,生物量为40-50mg·g^-1。HMM颗粒复合生物膜为石油烃污染地下水的化学吸附-生物降解联合修复提供了一种尝试。
Remediation organic pollutants in groundwater by organoclay has be proposed for many years. However, its application is restricted because its absorption capacity is limited, and fine granularity could change the direction of groundwater flow or fine particulate could also was dispersed by the flow. A new remediation method of the groundwater contaminated by petroleum hydrocarbon was proposed in this research. HDTMA modified montmofillonite (HMM) was immobilized by SA-CaCl2 to form granulated organoclay. Moreover, the granulated HMM was incubated with oil-degraded microorganisms and the stable biofilm was formed on the surface. By using the method, petroleum hydrocarbon could be absorbed on the granulated organoclay and biodegraded by the biofilm. Granulation ability of HMM was studied by using different contents of sodium alginate (SA) in CaCl2 solution. Also, the effects of the mass ratio of SA:HMM on Granulation ability were investigated. The results showed that stable granulated organoclay could be formed at 1:10 of SA:HMM when HMM was added in solutions with 1%-2% of SA and 2%-4% CaCl2. The diameter of the granulated HMM was in range of 2.5-4.0 mm and the it existed steadily from 30 days to 150 days under 200 rpm vibration in water and its oil-adsorbed capability maintained 80% of original HMM. Meanwhile, the optimum vegetate conditions of oil-degraded microorganisms were also achieved. When C/N/P was kept at 100:15:1,15 mL of microorganism concentration, 1% of oxidant content and initial pH5, the oil degradation could kept high level of actability. After finishing incubation oil- depredated microorganisms with granulated HMM, a stabile biofilm formed at 40-50 mg·g^-1 of biomass and 300 μm of thickness, and also showed high enzyme activity.