Enhanced Bioremediation of Field Agricultural Soils Contaminated with PAHs and OCPs

Document Type: Original Research Paper

Authors

1 MOE Key Laboratory of Pollution Process and Environmental Criteria, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environment Science and Engineering, Nankai University, Tianjin 300071, P.R. China

2 Zhonghuan Metallurgical Corporation, Beijing 10011, P.R. China

Abstract

Effect of different concentrations of ammonium chloride (NCL) and ammonium nitrate (NN)
and surfactants such as Tween-80, HPCD and rhamnolipids on the bioremediation of PAHs and OCPs was
investigated. The results showed that the best optimum concentration of NCL and NN was 50 g·kg-1, and the
PAHs degradation rate during 60 days of remediation was enhanced to 64.6% and 62.8% for NCL and NN,
respectively, which was approximately 45, 17, 10% higher than those in the control group, soil only added
microorganism, soil added microorganism and tourmaline. OCP removal rates were 51.7% and 50.4 % for NCL
and NN, respectively, which was 34% higher than the control group, 14% higher than the soil only added
microorganism, 9% higher than the soil added microorganism and tourmaline. The best dose of Tween-80,
HPCD and rhamnolipids was 2, 0.5 and 0.2 g·kg-1. When they were applied, the PAHs degradation rate during
60 days of remediation was enhanced to 69, 70.4 and 71.5%, respectively, which was approximately 52, 24
and 17% than those in the control group, soil only added microorganism, soil added microorganism and
tourmaline. Similarly, OCP removal rate was 42, 26 and 16% higher than those in the control group,
microorganism -added soil alone, soil added microorganism and tourmaline. Additionally, nutrients and surfactants
can promote the generation of soil hydrogen peroxidase and invertase enzyme. Hence, the present study
provides a promising combination remediation technology for the remediation of field soils contaminated by
PAHs and OCPs.

Keywords