BIOSORPTION OF Pb USING FRESHWATER ALGAE (SCENEDESMUS QUADRICAUDA)

The presence of heavy metals due to anthropogenic activities have caused chronic effects on human health. Heavy metals are also toxic to plants, animals and micro-organisms in the environment. Due to that, various methods have been developed to remove these heavy metals including chemical precipitation, electrochemical treatment, ion exchange, membrane technology and coagulation-flocculation. Somehow, these methods have many disadvantages such as produce high quantity of sludge and high cost for it to be conducted. Hence, an alternative process known as biosorption using algae is considered due to its low cost and ease of availability. However, biosorption process using algae has several major concerns especially on how to maximize the biosorption of heavy metal concentration. This research work focuses on the biosorption of Pb using freshwater algae by varying the biosorbent dosage, pH value and concentration of Pb solution in order to maximize the biosorptivity. Pb content was quantified using Atomic Absorption Spectroscopy (AAS). The maximum Pb uptake by the biosorbent was calculated using Langmuir and Freundlich isotherms. It was observed that the maximum biosorption in 60 ppm Pb can be achieved when using 0.05g biosorbent and at pH value of 4. The freshwater algae has the ability to adsorb Pb until 150 ppm of concentration metal solution and the maximum biosorption is 158.73 (mg/g) at optimum operating condition.