Perpustakaan Digital ITB

Heavy metals are listed among priority metallic pollutants known to cause irreversible health effects and easily magnify in higher trophic of the food chain. Microalgae has been explored for biosorption potential. In this study, aims to evaluate the potential of living and dead biomass to remove Cd (II) and Cr (VI) ions from aqueous solution and surface water. The microalgae were taken from IPAL Bojongsuang. The result of isolated was indicated as Spirulina sp. FTIR spectrum of biomass revealed the presence of amino acid (-NH2), carbonyl (- C=O), carboxyl (-COOH) and hydroxyl (-OH) groups. The scanning electron micrograph clearly revealed the surface texture and morphology of the biosorbent and biosorptive of heavy metals was significant effected by pretreatment of sorbents. The results shown that HCl and Na2CO3 were gives maximum improvement on biosorption of 88.70% on Cd (II) removal and 85.50% on Cr (VI) removal. Biosorption of Cd (II) and Cr (VI) ions were evaluated under different conditions that included pH, temperature, biomass concentration, metal concentration and contact time were studied. Maximum metal uptake was observed at pH = 6 and pH = 2 respectively. Maximum metal uptake (qmax) of Cd (II) and Cr (VI) were 23.98 and 26.38 mg/g respectively. Mechanism of Cr (VI) removal was observed as Cr (VI) reduced to Cr (III), the optimum reduction was found at 45? was observed 87.30%. The biosorbed metal ions was recovered using 65% (v/v) HNO3, 0.1M HCl, 0.5M EDTA, 0.1M NaOH as regenerants. The desorption test revealed that HNO3 was the best for the elution of metals from the tested microalgae, the recovery percentage of 100% was observed. Biosorption of Cd (II) and Cr (VI) from surface water was investigated. Which shown that microalgae were potential to remove these heavy metal ions from surface water. The biosorption of Cd (II) ion was followed well with Langmuir isotherm model with R2 = 0.9988 and Freundlich model was fitted better for Cr (VI) with R2 = 0.9966. The biosorption of Cd (II) ion was followed the pseudo-first-order kinetic, which evidence of single site adsorption. Whereas Cr (VI) was by Ho’s pseudo-second-order kinetics confirming a multisite interaction. Biosorption of these ions by microalgae was controlled by chemisorption involving valence forces through sharing or exchange of electrons between sorbent and sorbate.