Characteristics and Chlorpyrifos Degradation of a Biomix in Biobed

Abstract

The biobed, a simple and cheap on-farm construction intended to collect and degrade spills of pesticides, can be used to minimize the risk of pollution when handling such pesticides. The biomix plays the most important role in the adsorption and degradation of pesticides in the biobed. This study aimed at (i) construcing a biomix from the available resources, (ii) determining the physical, chemical and biological characteristics of biomix at different pre-incubation times and (iii) assessing the ability to degrade Chlorpyrifos of the biomix. The results showed the water holding capacity, pH, organic C, total N, and C/N ratio of the biomix were 60%, 7.85, 20,35%, 1.26% and 16,15, respectively. Ligninolytic enzyme activity of the biomix pre-incubated for 0, 15 and 30 days were 45, 83 and 60 units/kg, respectively. For the biomix pre-incubated for 15 days, (i) the numbers of total bacteria, actinomyces, and molds were 6.41´10⁸, 6.4´10⁵ and 10⁶ CFU/g, respectively, (ii) the numbers of cellulolytic, hemi-cellulolytic and ligninolytic were 2.22´10⁴, 3.45´10⁴ and 4.22´10⁴ CFU/g, respectively, and (iii) the microbial respiration was 323 mg CO₂/100 g. The highest degradation of Chlorpyrifos was 96.62