Abstract:
Acid mine drainage (AMD), with a low pH and relatively high concentration of heavy metals, is an environmental
problem in mining activities. Contracted wetlands is one of the AMD management methods, in which organic matter
(OM) plays very vital role in reducing the concentration of heavy metals in AAT through absorption and precipitation
processes. Three types of OM (empty bunches of oil palm, chicken manure and water hyacinth) and 5 levels of OM
(0, 10, 20, 30 and 40 Mg ha−1
) were applied to reclaimed-mining soils (RMS) in an incubation study. A batch
experiment was then carried out to quantify the effect of OM application on the maximum sorption capacity (Qmax)
of iron (Fe) from the AMD onto mixed soil-OM. The application of OM resulted in increases in soil pH, carboxylic
groups, and total functional groups, in which these increases varied based on the types and amounts of OM application.
The application of OM increased Qmax values for Fe from 2077 to 2348−3259 mg Kg-1
(water hyacinth), to
2607−3635 mg Kg-1
(chicken manure), and to 2219−2992 mg Kg-1
(empty bunches of oil palm). Increasing these
Qmax values may ascribe to increasing functional groups of the RMS with OM application. Results of this study
demonstrate that importance of different types and amounts of OM in controlling the sorption of Fe from AMD onto
soils.
Keywords: decomposition; negative charge; adsorption; functional groups; metal removal
