Evaluation of Dumpsite Soil as Compost and Assessment of Heavy Metal Concentration in Selected Plants from Municipal Solid Wastes Dumpsite of Brgy. Lalaan, Municipality of Silang, Cavite

Abstract

INTRODUCTION

The generation of waste increases proportionally with the consumption of products and services. The density of these invaluable remains increases dramatically with the local population while its post-processing takes place at a slower pace. Waste, therefore, cannot be avoided but can be managed. A simple way to deal with this massive amount of waste is to restore value from it. One way of restoring its value is through composting. Thus, this research paper analyzed the compost suitability and quality of the soil in a closed Municipal Solid Waste dumpsite in Brgy. Lalaan, Silang, Cavite as well as the heavy metal concentration (Cd, Pb, Zn, and Cu) of the plants (Ipomoea batatas, Ipomoea aquatic, and Capsicumfrutescens) growing in the area.

METHODS

The plants and the soil samples were collected from the three multi-depths stations and were subjected to physical (moisture and water holding capacity), chemical (pH, organic matter, electrical conductivity, total N, available P, exchangeable K) assessments, including heavy metal analysis using Atomic Absorption Spectrophotometer (AAS).

RESULTS

The soil samples collected from the three different depths of the MSW dumpsite in Brgy. Lalaan Silang, Cavite showed no significant difference in terms of their physicochemical characteristics. The soils have potential as a soil compost with favorable results in both physical parameters and chemical parameters, except for the organic matter content. In terms of heavy metal concentrations of Zn, Cu, Cd, and Pb, all the three depths were given the highest score value in terms of the clean index. The study also revealed that the concentrations of Zn, Cu, Cd, and Pb in the MSW dumpsite soil are all within the permissible limit set by WHO and FAO. Likewise, the concentrations of these heavy metals in the different parts of the plants (Ipomoea aquatica, Ipomoea batatas, and Capsicum frutescens) did not reach and exceed the critical levels.

DISCUSSIONS

The dumpsite soil can be graded Class A as the results are compliant with physical and chemical parameters for compost while the heavy metal concentrations in the plants are within the permissible limit set by WHO/FAO with each of the parts significantly below the toxicity level. The findings further recommend the use of dumpsite soil as compost and the consumption of Ipomoea batatas, Ipomoea aquatic, and Capsicum frutescens grown in the premises.