典型土壤改良剂对污染物生物可利用性的影响

Effect of typical soil amendments on the bioavailability of pollutants

摘要:

土壤有机污染是当前世界面临的一个严峻环境问题,已经引起广泛关注.污染土壤添加改良剂是一种成本较低、环境友好的土壤原位修复方法,具有极大的应用前景.然而,土壤改良剂对有机污染物生物降解起促进或抑制作用主要取决于其对有机污染物生物可利用性的影响.土壤改良剂对有机污染物的生物可利用性有多方面的影响.一方面,土壤改良剂可通过吸附作用固定污染物,降低生物可利用性；另一方面,土壤改良剂中的溶解性有机质可促进有机污染物的溶解和解吸,增加生物可利用性；另外,某些土壤改良剂可提高微生物活性,促进污染物降解.本文从污染物吸附解吸、污染物与微生物之间传质以及微生物丰度和活性3个方面出发,探讨常用土壤改良剂,包括生物炭、堆肥产物和表面活性剂,对有机污染物生物可利用性的影响,以期为寻找具有较高修复效率的土壤改良剂提供一定的参考.

Abstract:

Soil organic contamination is a serious environmental issue that has attracted wide attention. As a low cost and environmental friendly method, the addition of soil amendments has great prospect in soil situ remediation. However, the efficiency of soil amendments on the biodegradation of organic pollutants depends on its impact on bioavailability. Soil amendments have multiple influences on the bioavailability of organic pollutants. On the one hand, organic pollutants are immobilized by soil amendments due to adsorption effect, thus decreasing the bioavailability of the organic pollutant. On the other hand, dissolved organic matter from soil amendments can facilitate the desorption of the organic pollutants and increase the bioavailability. Moreover, microbial activity can be enhanced by soil amendments, which is also beneficial for organic pollutants biodegradation. This paper investigates the impact of three common soil amendments (i.e., biochar, compost, and surfactants) on the bioavailability of organic pollutants from the perspectives of adsorption and desorption, mass transfer between organic pollutants and microorganism, as well as microbial abundance and activity. Results of this study will provide reference for finding soil amendments with high efficiency.