Rambutan (Nephelium lappaceum) Peels as Alternative Material for Biosorption of Copper in Water through Filtering

Abstract

INTRODUCTION

One of the ongoing problems in either urban or rural community is the pollution of heavy metals. Heavy metals are commonly found contaminated in water and soil areas especially those that are near factories, industries, and mining sites. Consumption or exposure to certain amounts of these metals are harmful and dangerous to us, humans, and to the environment, since it had led to different diseases and disorders in the past. Rambutan (Nephelium lappaceum) is one of the fruits that are common and abundant in our country, and the researcher tends to use its lignin properties for the biosorption of heavy metals.

METHODS

About 500 grams of Rambutan Peels (RP) from the fruit was collected and cut it into small pieces. It was washed thoroughly with tap and then distilled water. The collected peels were sun-dried by for 3 consecutive days and ground into smaller particles, 1mm to 5mm in size. The researchers initially secured the dried peels in an airtight container. A simple column model was prepared using plastic bottles which will contain the dried RP and the copper solution (10 ppm). 2 sets of experiment were prepared each with 4 columns (namely Cu 1, Cu 2, Cu 3, Cu 4).

RESULTS

In Set 1, the maximum adsorption capacity for 1g of rambutan peels was determined on Cu 2 consisting 150 ml of Cu2+ solution. Using the formula q=[(Ci-Cf)* V] / W, the adsorption capacity for the RP obtained was 0.3 mg/g. 1 gram of rambutan peels reduced the 10 ppm copper solution (150ml) to 8 ppm showing 20% reduction. For Set 2, Cu 1 had the lowest reduction rate of 40% which is an approximate of 4 ppm was reduced. In contrast, Cu 3 with 15g of RP and Cu 4 with the highest amount at 20 g showed the highest reduction rate of 70% which is approximately 7 ppm. Therefore, the results proved a direct relationship between the amount of dried RP and its reduction rate.

DISCUSSIONS

It was proved by the obtained results that rambutan peels are capable of filtering copper ions in a solution but in very low rates compared to other agricultural wastes like banana peels, which showed higher reduction rates in other studies. Significant changes weren't observed from the results and it may imply that better handling of the materials is required to enhance the capabilities of the peels.