Skip to main content
ARS Home » Southeast Area » Florence, South Carolina » Coastal Plain Soil, Water and Plant Conservation Research » Research » Publications at this Location » Publication #320597
Title: Enhancing cleanup of heavy metal-polluted landfill soils and improving soil microbial activity using green technology with ferrous sulfate

Author
item Sigua, Gilbert
item CELESTINO, ARNELL - Central Luzon State University
item ALBERTO, RONALDO - Central Luzon State University
item PAZ-ALBERTO, ANNIE - Central Luzon State University
item Stone, Kenneth - Ken

Submitted to: International Journal of Environmental Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/4/2016
Publication Date: 4/19/2016
Citation: Sigua, G.C., Celestino, A., Alberto, R.T., Paz-Alberto, A.M., Stone, K.C. 2016. Enhancing cleanup of heavy metal-polluted landfill soils and improving soil microbial activity using green technology with ferrous sulfate. International Journal of Environmental Protection. 6(1):97-103.

Interpretive Summary: The environmental problems caused by landfills are numerous. The wide-spread pollution of soils due to heavy metals from several sources especially in landfills is an increasingly urgent problem because of its contribution to environmental deterioration and intensive degradation of soil microbial biodiversity. Despite the arguments over landfills in general, there has been few or no effort was undertaken to clean up contamination of heavy metals in abandoned landfills. Our study proposed using a green technology or “phytoremediation” with elemental sulfur in enhancing cleanup of heavy metal–polluted landfill soils. Composite soil samples were collected near an open abandoned dump site in Cabanatuan City, Nueva Ecija, Philippines. Three rates (0, 40 and 80 millimole per kilogram) (mmol/kg) of elemental sulfur were thoroughly mixed with the soil. Four healthy seedlings of mustard (Brassica juncea, L) were transplanted to each pot. Important findings from our greenhouse study are as follows: 1) soil pH decreased in all the treatments with application of elemental sulfur when compared to the control; 2) solubility of heavy metals especially copper, zinc and manganese in the soils following harvest of mustards was significantly increased with elemental sulfur application; and 3) application of elemental sulfur significantly enhanced microbial activities in contaminated soils. Our study has demonstrated the beneficial outcome of green technology in combination with elemental sulfur in cleaning up heavy metals contamination in landfills and at the same time improving soil microbial biomass following phytoremediation. However, additional research is still needed to better understand the long-term effects of green technology in combination with sulfur during phytoremediation. Several factors must be considered in order to accomplish successful remediation result. The most important factor is a suitable plant species, which can be used to uptake the contaminant efficiently by acting both as “accumulators” and “excluders."

Technical Abstract: Landfills have led to some of the most intense battles over pollution that has ever been seen. With the population skyrocketing worldwide, these landfills will only become more of a public issue as time goes on. Heavy metals from several sources especially in landfills are an increasingly urgent problem because of its contribution to environmental deterioration and intensive degradation of soil microbial biodiversity. Despite the arguments over landfills in general, there has been few or no effort was undertaken to clean up contamination of heavy metals in abandoned landfills. Our study proposed using a green technology or “phytoremediation” with elemental sulfur in enhancing cleanup of heavy metal–polluted landfill soils. Composite soil samples were collected near an open abandoned dump site in Cabanatuan City, Nueva Ecija, Philippines. Three rates (0, 40 and 80 mmol/kg) of elemental sulfur were thoroughly mixed with the soil. Four healthy seedlings of mustard (Brassica juncea, L) were transplanted to each pot. Soil pH showed a decreasing trend for soils treated with 0 and 80 mmol/kg of elemental sulfur after 15 days (8.12 to 7.38) and after 25 days (8.56 to 7.78). Application of elemental sulfur significantly enhanced microbial activities in contaminated soils. Average respiration rate in soil with 0 mmol/kg sulfur was about 2.0 mg/kg carbon dioxide (CO2)-carbon (C) compared with 19.0 mg/kg CO2-C for soils amended with 80 mmol/kg of elemental sulfur. Although dry matter yield and uptake of heavy metals by mustard were somewhat variable with sulfur application, solubility of copper, zinc and manganese in soils was significantly increased with sulfur application (p=0.001). Our study has demonstrated the beneficial outcome of green technology in combination with elemental sulfur in cleaning up heavy metals contamination in landfills and at the same time improving soil microbial biomass following phytoremediation.