Ability of Tahong (Perna viridis), Kuhol (Helix pomatia), and Talaba (Crassostrea gigas) to de-lead simulated waste water preparations

Abstract

Shells of Tahong {Perna viridis), Kuhol ((Helix pomatia), and Talaba (Crassostrea gigas) are considered wastes and are normally dumped in open garbage areas or back to the aquatic system. Many studies showed that family of oysters, mussels, and snails are used as bio-indicators or used in accumulation monitoring studies of metals like Cd, Pb, Cu and Hg since their soft tissues absorb it. Their shells, as they may contain chitin or chitosan may also have the ability to absorb heavy metals.As the waste shells are being reused/recycled, waste materials in the environment are decreased. Vectors of diseases that swarm waste areas will be diminished and thus safeguard public health.In general, this study aimed to assess the ability of shells of Perna viridis (tahong), Crassostrea gigas (talaba) and Helix pomatia (kuhol) to de-lead simulated lead-contaminated waste water. Specifically, this study aimed to compare the ability of shells of Perna viridis (tahong), Crassostrea gigas (talaba) and Helix pomatia (kuhol) to de-lead simulated lead-contaminated waste water. It also aimed to assess if concentrations of lead in waste water affect the absorption of lead by the shell samples and if variances in types of shells affect absorption of lead in waste water. Tahong, Talaba and Kuhol absorbed lead in simulated waste water. However, the inherent amount of lead in the different shells affected its ability to absorb it. Talaba and kuhol, due to its inherently high lead concentrations failed to absorb lead from simulated waste water as the amount of the heavy metal increased. Statistical analysis showed that the concentrations of the simulated waste water affected the absorbance of lead by chitin and chitosan from different shells. Also, chitin and chitosan extracted from different kinds of shells affected lead absorption in varied concentrations of simulated waste water. Tahong shells showed the most efficient absorption of lead from simulated waste water preparations. Using the different shells in the differently concentrated SWW, the percentage of lead removed ranged from -15.899% to 63.539%. Flameless Atomic Absorption Spectrophotometer was used to quantitate the lead levels in simulated waste water, and chitin and chitosan extracted from the three waste shells used in this study. As there is promise to clean the waste waters from lead pollutants using Tahong, Talaba and Kuhol, it is recommended that other shell wastes be studied for similar objectives as this study. Likewise, pH of waste water, time of contact, temperature during treatment and agitation must be looked into to optimize the de-leading ability of these shells. Further absorption of other heavy metals is suggested to be analyzed as well.