REMOVAL OF HEXAVALENT CHROMIUM FROM CONTAMINATED WATERS USING SYZYGIUM CUMINI SEED BIOSORBENT

Hazardous metals such as chromium in industrial wastewater followed by leaching to ground water are threat to the environment because of their toxicity and their impact on our ecosystem. Among the different heavy metals, chromium (VI) is a common and very toxic pollutant being introduced into natural waters from a variety of industrial wastewaters. Chromium (III) is an essential element for organisms that can disrupt the sugar metabolism and cause heart conditions, when the daily dose is too low. Chromium (VI) is mainly toxic to organisms. It can alter genetic materials and cause cancer. Adverse health effects associated with Cr (VI) exposure include occupational asthma, eye irritation and damage, perforated eardrums, respiratory irritation, kidney damage, liver damage, pulmonary congestion and edema, upper abdominal pain, nose irritation and damage, respiratory cancer, skin irritation, and erosion and discoloration of the teeth. Some workers can also develop an allergic skin reaction, called allergic contact dermatitis. The Chromium (VI) discharged from various industries has potential to contaminate drinking water sources and is one of the most important environmental problems due to its health impacts on human. Adsorption is one of the effective techniques for chromium (VI) removal from wastewater. In the present study, adsorbent has been prepared from Syzygium cumini (L.) seed and studies are carried out for chromium (VI) removal. The parameters investigated in this study are contact time, adsorbent dosage, temperature, variable initial chromium (VI) concentration and pH using Diphenyl carbazide as color developing reagent and taking the absorbance at 540 nm spectrophotometrically. The adsorption process of chromium (VI) is tested with Linear, Langmuir and Freundlich isotherm models. Application of the Langmuir isotherm to the systems yielded maximum adsorption capacity of 13.15 mg/g at a solution pH of 7 having Cr (VI) concentration 50 mg/L and biosorbent dose 1g/L. The adsorption of chromium (VI) was found to be maximum 71.58 % at low pH values of 2 having Cr (VI) concentration 50 mg/L and biosorbent dose 1g/L. The contact time of 60 min resulted to the 26.96% adsorption of metal in 50mg/L solution using adsorbent dose of 1g/L and can used for removal