The Influence of Organic Matter Application Upon The Effectiveness of Reduction of Heavy Metals: Lead (Pb) and Cadmium (Cd) by Hyperaccumulator Plant

Abstract

Organic matter is able to bind heavy metals. Soil enrichment with organic matter can reduce the availability of metal species as a result of the complexing of heavy metal free ions. This research examined the chelation of lead (Pb) and cadmium (Cd) waste-source heavy metals by organic matter, and the utilization of hyperaccumulator plants to remediate contaminated lands. The study was aimed to (a) analyze the influence of guano organic matter application to reduce heavy metals, Pb and Cd, and the combined effectiveness with plants; (b) to identify the capability of three plants as hyperaccumulator plants. Guano was used as an organic matter source in soils artificially contaminated with Cd and Pb from industrial solid waste. The research was conducted in two phases. The first research phaseused a combination of artificial Pb and Cd with guano. The second Research phase involved two dosages of guano and three concentrations of waste. Three plants were used as hyperaccumulator plants: elephant grass (Pennisetum purpureum), chinese cabbage (Amarantus tricolor), and water spinach (Ipomoea aquatica). The study results indicated that guano had the capability to chelate more than 90% of Pb and a maximum of 61% of Cd, hence reducing the concentration of Pb and Cd. Other results showed that the three hyperaccumulator plants generated different responses toward the addition of heavy metals (Pb and Cd). From the calculation of the Bio-Accumulation Factor (BAF), the value for Cd showed that P. Purpureum and A. Tricolor had good potential as hyperaccumulators. Only P purpureum had the capacity as a hyperaccumulator for Pb, while I.aquatica was not a yperaccumulator plant for Cd or Pb.