Peel Wastes of Ananas comosus (L.) Merr., Sandoricum koetjape Merr., Citrus nobilis Lour. as Lead and Cadmium Biosorbent in Manila Tap Water

Abstract

Contaminated water from Manila, Philippines must be remediated. The use of peel wastes from Ananas comosus(L.) Merr. (Pineapple), Sandoricum koetjape Merr.(Santol) and Citrus nobilis Lour. (Dalanghita) , as agents in removing heavy metals from water could be cost effective. This study aimed to evaluate the capacity of peels to remove lead and cadmium in contaminated water. Furthermore, it aimed to determine the optimum pH, effect of contact time and the initial concentrations of heavy metals on the bio-sorption in the identified peels. The study was carried out by batch process. Biomass was added to known amounts of metals in solution with adjusted pH. After vacuum filtration, the filtrates were analyzed for residual heavy metal concentration using atomic absorption spectroscopy. Peel bio-sorption was optimum at pH 5. The amount of heavy metals adsorbed increased with time until 120 mins. The percent bio-sorption efficiency decreased with an increase in initial heavy metal concentration. The peels followed the pseudo second order kinetics, and the langmuir isotherm model with the bio-sorption of lead. For cadmium removal, pineapple and santol followed Langmuir isotherm model. For the actual contaminated tap water from Manila, santol showed the highest percent biosorption efficiency for lead and cadmium.