Accelerated bioremediation of a complexly contaminated river sediment through ZVI-electrode combined stimulation.

Affiliation

Shi K(1), Liang B(2), Guo Q(1), Zhao Y(1), Sharif HMA(3), Li Z(1), Chen E(4), Wang A(5).
Author information:
(1)State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China.
(2)State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China; School of Civil & Environmental Engineering, Harbin Institute of Technology
(Shenzhen), Shenzhen 518055, China. Electronic address: [Email]
(3)College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China.
(4)The Environmental Monitoring Center of Gansu Province, Lanzhou 730020, China.
(5)State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin 150090, China; School of Civil & Environmental Engineering, Harbin Institute of Technology
(Shenzhen), Shenzhen 518055, China; Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.

Abstract

Complexly contaminated river sediment caused by reducible and oxidizable organic pollutants is a growing global concern due to the adverse influence on ecosystem safety and planetary health. How to strengthen indigenous microbial metabolic activity to enhance biodegradation and mineralization efficiency of refractory composite pollutants is critical but poorly understood in environmental biotechnology. Here, a synergetic biostimulation coupling electrode with zero-valent iron (ZVI) was investigated for the bioremediation of river sediments contaminated by 2,4,6-tribromophenol (TBP, reducible pollutant) and hydrocarbons (oxidizable pollutants). The bioremediation efficiency of ZVI based biostimulation coupling electrode against TBP debromination and hydrocarbons degradation were 1.1-3 times higher than the electrode used solely, which was attributed to the shape of distinctive microbial communities and the enrichment of potential dehalogenators (like Desulfovibrio, Desulfomicrobium etc.). The sediment microbial communities were significantly positively correlated with the enhanced degradation efficiencies of TBP and hydrocarbons (P < 0.05). Moreover, the coupled system predominately increased positive microbial interactions in the ecological networks. The possible mutual relationship between microbes i.e., Thiobacillus (iron-oxidizing bacteria) and Desulfovibrio (dehalogenator) as well as Pseudomonas (electroactive bacteria) and Clostridium (hydrocarbons degraders) were revealed. This study proposed a promising approach for efficient bioremediation of complexly contaminated river sediments.