硫磺和放线菌强化植物修复土壤镉污染

Combination of sulphur and actinomycete to enhance the efficiency of phytoremediation in cadmium contamination soil

为了强化耐受重金属镉(Cd)的植物包心芥菜对土壤中Cd污染的富集及转运效率,以包心芥菜为研究对象,向土壤中添加0.3%的硫磺和接种不同数量的放线菌Act12(0.5,1.0,1.5,2.0g/kg),通过盆栽实验,研究不同处理间根际土pH值的变化规律、包心芥菜地上和地下部分Cd的积累量、植物抗氧化酶系的变化以及根系活力.结果表明:添加0.3%硫磺和2.0g/kg放线菌Act12后,根际土pH值下降最大,相比对照下降了14.5%.而添加0.3%硫磺和1.5g/kg的放线菌Act12,包心芥菜地上部分Cd的含量最高,转运系数最大,相比对照,Cd含量提高了79%,并且植物地上部分的干重最大.添加放线菌Act12对植物的抗氧化系统有积极作用,CAT、POD、SOD含量均在0.3%硫磺和1.0g/kg放线菌Act12的添加组合下达到峰值,放线菌Act12还可提高植物的根系活力,降低丙二醛的含量.综上表明,添加硫磺和放线菌Act12均可强化包心芥菜吸收土壤中Cd的能力,其中0.3%硫磺和1.5g/kg放线菌Act12的添加组合强化效果最佳.

Enhanced phytoremediation with the involvement of microbes and chemicals has become an alternative technique to remediate the contamination of heavy metal in soils. The combination of 0.3% sulfur and three levels of actinomycete Act 12 enhanced phytoremediation has been experimented to remediate the Cd-contaminated soil by employing Brassica juncea, a Cd-tolerant plant. The Cd accumulation in plant root and shoot part, antioxidant enzyme activities and plant root activity were measured to explore the potential mechanisms. The results showed that the combination of 0.3% sulfur and 2.0 g/kg Act12 addition significantly reduced Rhizosphere pH by 14.5%. By comparison, the combination of 0.3% sulfur and 1.5 g/kg Act12 addition treatment dramatically increased Cd accumulation in plant shoot by up to 79%. Act12 addition positively enhanced plant antioxidant system, and the values of CAT, POD, and SOD reached the peak in the treatment with a combination of 0.3% sulfur and 1.0 g/kg Act12. Additionally, Act12 addition boosted plant root activities and reduced the content of MAD. Our study indicated that both sulfur and actinomycete Act 12 can enhance the absorption capacity of Cd by Brassica juncea, and the combination of 0.3% sulfur and 1.5 g/kg Act12 addition achieved the best results in our experiments.