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ARS Home » Pacific West Area » Riverside, California » Agricultural Water Efficiency and Salinity Research Unit » Research » Publications at this Location » Publication #345004

Research Project: Identifying, Quantifying and Tracking Microbial Contaminants, Antibiotics and Antibiotic Resistance Genes in Order to Protect Food and Water Supplies

Location: Agricultural Water Efficiency and Salinity Research Unit

Title: Analysis of the effects of natural organic matter in zinc beneficiation

item SILVA, RENE - Chonbuk National University
item BORJA, DANILO - Chonbuk National University
item HWANG, GUKHWA - Chonbuk National University
item HONG, GILSANG - Chonbuk National University
item GUPTA, VISHAL - Ep Minerals
item Bradford, Scott
item ZHANG, YAHUI - Memorial University Of Newfounland
item KIM, HYUNJUNG - Chonbuk National University

Submitted to: Journal of Cleaner Production
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/2/2017
Publication Date: 9/4/2017
Citation: Silva, R.A., Borja, D., Hwang, G., Hong, G., Gupta, V., Bradford, S.A., Zhang, Y., Kim, H. 2017. Analysis of the effects of natural organic matter in zinc beneficiation. Journal of Cleaner Production. 168:814-822.

Interpretive Summary: Soil and rock wastes from mining operations frequently contain heavy metals that may leach out over time because of the action of some microorganisms. Experimental studies were conducted to investigate the influence of natural organic matter (NOM) in the soil water on this bioleaching process. Results indicated that the rates of bioleaching were not directly influenced by NOM in soil solution, but rather that NOM indirectly influenced bioleaching by inhibiting bacteria attachment to the soil particles. This information will be of interest to scientists and engineers concerned with the recovery and environmental fate of heavy metals in mining wastes.

Technical Abstract: In this study, we present the analysis of the effects of Natural Organic Matter (NOM) in zinc beneficiation from abandoned mine tailings using bioleaching technologies. We used standardized Suwannee River Humic Acid (SRHA) as the NOM source to analyze the importance of the quality of the process waters and the possible side effects of NOM accumulated on mine tailings when exposed to environmental conditions. Our study proposes the use of process waters as an important variable to maintain high process efficiency. Concentrations of 20 ppm of SRHA suspended in the bioleaching medium reduced the Zn removal efficiency by 10% as compared with the process without SRHA. Similarly, at concentrations of 50 ppm of SRHA, the Zn removal efficiency decreased by 20% as compared with the process without SRHA. However, our study refutes the view that the accumulation of NOM on mine tailings could possibly reduce the process efficiency. We conclude that the suspended NOM was able to alter the process efficiency by reducing the bacterial attachment on the mine tailing’s surface, which suggested the importance of the bacterial contact mechanism.