การเปรียบเทียบการย่อยสลายไดยูรอนที่ปนเปื้อนในดินโดยธรรมชาติการใช้สารเร่งทางชีวภาพและการเติมเชื้อจุลินทรีย์ / สุรชัย ศรีธรรมภิวัฒน์ = Comparison of natural, biostimulated and bioaugmented degradations of diuron contaminated in soil / Surachai Sritampiwat
Diuron (3-(3,4-dichlorophenyl)-l,l-dimethylurea) is a phynylurea herbicide widely used for vegetation control in agricultural areas such as cassava, pineapple, corn, cotton and sugar cane fields and nonagricultural area; for example, along road and railway line. However, diuron is very toxic, harmful and classified as carcinogen. It also sorbs well on soil surface and has low solubility, thus the contaminations of diuron have been found in environmental media including soil and water. It is necessary to develop a remediation technology for diuron in the environment. The objective of this study was to evaluate the best bioremediation technique for diuron contaminated soil treatment. Three types of bioremediation techniques, comprising of natural attenuation, biostimulation and bioaugmentation (with bacterial pure culture and bacterial consortium), were compared in two soil types, namely loam soil and silty clay soil, which contained 20 and 100 ppm of diuron. With 20-ppm diuron in loam soil, the greatest diuron degradation was observed with natural attenuation, i.e. 17% degradation within 8 weeks under the experiment condition A, while under the experiment condition B, diuron in natural attenuation and bioaugmentation were able to be highly degraded with maximal activity by 31% within 15 days. With 100-ppm diuron in loam soil, the greatest diuron degradation was observed with bioaugmentation with consortium A1 by 22% within 15 days. Under silty clay soil condition, there were no noticeable biodegradation among three types of treatment. The increasing of total microbial activity was detected with biostimulation with the addition of 1,000 ppm NH4Cl by 4-fold in loam soil in both 20-ppm and 100-ppm diuron within 15 days.
