Optimization of lead (II) removal in leachates using Moringa oleifera seeds

Mae Ann De Castro,John Raymond Barajas,Cyril Ann Agripa,Faye Taniegra

doi:10.1051/matecconf/201926806011

Abstract

The absence of comprehensive programs in regulating release of lead to the environment in growing cities situated in developing countries results to widespread intrusion of lead bioaccumulation in their primary sources of food. As a result, a significant increase in lead related diseases continually grows in many low income regions. In an attempt to provide a means of minimizing lead bioaccumulation, we test the extent to which Moringaoleifera seeds (MOS) removes lead (II) ions in aqueous solution. A box-behnken experimental design was used to obtain the optimal conditions in the lead (II) removal process. MOS dosage, initial lead (II) concentration, and pH were found to have significant effects on the percent removal of lead (II) in solution. Actual values of these independent variables were chosen on the basis of preliminary experimental results. Optimum conditions were found to be: MOS dosage 10.0 g/L, initial lead (II) concentration 20.0 ppm, and pH at 5.5. Lead removal using MOS was also performed at optimal conditions. In conclusion, a high lead (II) removal using MOS strongly suggests its potential to be used as a means of treating liquids highly contaminated with lead.

Highlights

Rapid urbanization has been identified as a primary driving force that induces heavy metal contamination in the environment
To test whether lead can be flocculated by Moringaoleifera seeds (MOS), trials were performed at an initial lead concentration of 2 and 20 ppm
It is noted that percent lead removal decreases as coagulant dosage decreases

Summary

Introduction

Rapid urbanization has been identified as a primary driving force that induces heavy metal contamination in the environment. Due to a significant increase in construction activities fuelled by economic growth and expansion, the volume of construction and demolition wastes (CDW) produced has grown exponentially. The European Union alone produces nearly 850 million tons of CDW annually [1]. In 2014, the United States produced CDW with the same magnitude [2]. It is estimated that with this cumulative amount of CDW, landfills would be filled to about 40% of their capacities [3]. The piling up of CDW in landfills, as a result, has driven the occurrence of heavy metal contamination in these dumping sites. Toxic heavy metals (i.e. Pb) in the leachate of landfills were found to be present at concentrations beyond 100 ppm [4].If these toxic pollutants would remain at concentrations beyond threshold limits, areas near the perimeter of the dumping site and pristine matrices beneath the landfill would be at serious risks to heavy metal pollution

Methods

Results

Conclusion