BIOBEDS - BIOTECHNOLOGY FOR ENVIRONMENTAL PROTECTION FROM PESTICIDE POLLUTION

摘要

Point sources of pesticides, for instance frequently occurring at the filling of spraying equipment, are one of the most dominant reasons for pesticide pollution of surface and ground waters today. This contaminant risk can be minimized by using biobeds. Biobeds are facilities intended to retain and degrade pesticide spills. In its original design they consist of a biomixture, a clay layer at the bottom and a grass cover on the surface. The typical Swedish biomixture consists of straw, topsoil and peat (50-25-25 % v/v). The straw stimulates the growth of lignin-degrading fungi and the formation of ligninolytic enzymes (such as manganese and lignin peroxidases), which can degrade many different pesticides. The soil provides sorption capacity and other degrading microorganisms and the peat contributes to high sorption capacity and also helps to regulate the humidity of the system. A grass layer covering the biobed also helps to keep the correct humidity and can be used as an indicator revealing pesticide spills. The clay acts as an impermeable layer at the bottom. More than 1500 biobeds are in use in Sweden today and this concept has proven to be an effective and inexpensive solution to mitigate the release of pesticides to the environment.