International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 10 Issue: 07 | July 2023
p-ISSN: 2395-0072
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Removal of Hexavalent Chromium by Adsorption using low-cost Adsorbents and Activated Carbon Sangeeta1, Rekha H B2 1PG Student, 2Associate Professor, Civil Engineering Department, UVCE, Bangalore University, Bengaluru,
Karnataka, India. ---------------------------------------------------------------------***---------------------------------------------------------------------
Abstract - The removal of heavy metal ions from water and
persistent nature non‐biodegradable. Due to their highly solubility in aquatic environments, heavy metals are spontaneously immersed by fishes and vegetables. When these metals are encounter human, they are penetrating our body by water, air, food or absorption through skin. (Himanshu Patel, 2020)
wastewater has received a lot of attention. Although the methods that are most frequently used to treat contaminated water are adsorption ones. The current study's objective was to look into the viability of using low-cost natural-material adsorbents in these kinds of technological applications. The percentage removal of hexavalent chromium was evaluated under two process batch and column process. Batch adsorption was carried out with a variety of parameters, including pH, contact time, and adsorbent dose. Rice husk silica in the batch process eliminated a larger percentage of hexavalent chromium, or 64.25%, than rice husk and sawdust. We performed column adsorption with various flow rates and bed heights. Results show that rice husk silica removed 98.08% of the hexavalent chromium better than rice husk and sawdust under the best conditions, which were a lower flow rate (1 mL/min) and a higher bed height (15 cm). When batch and column studies are compared, column studies are favored over batch treatments. Comparing it with activated carbon it was seen to be around 98.32 % where the reduction using the above process shows reduction of 98.08% using the low-cost adsorbent. Thus, the rice husk silica in this study showed a good potential for the removal of hexavalent chromium in both batch and column process.
Chromium is a typical pollutant that is discharged into natural waters as a result of various industrial wastewaters. On the other hand, chromium-based catalysts are also typically used in a variety of chemical processes, such as selective hydrocarbons being oxidized. As per the World Health Organization (WHO), According to drinking water regulations, 0.05 ppm of total chromium is the highest permissible level. mgl−1. (Mojdeh Owlad, 2008) The metal chromium, which is the chromium (0) form, is used for making steel. Chromium (VI) and chromium (III) are used for chrome plating, dyes and pigments, leather tanning, and wood preserving. (Mojdeh Owlad, 2008) Removal of Chromium (VI) ions from industrial wastewater is achieved principally by the application of several conventional processes such as reduction followed by chemical precipitation, absorption, activated carbon, electrochemical processes, ion exchange, biological operations, catalytic oxidation, and membrane processes. These methods require large amounts of chemical substances and energy, generation of toxic sludge, fouling, high capital and operational costs, expensive equipment requirement and efficient monitoring system, (Sivakumar, 2015). The need of safe and economical methods for the removal of heavy metal ions from contaminated water has developed interest towards the Adsorption process with low-cost adsorbents (Naba kumar, 2014).
Key Words: Rice husk silica, sawdust, hexavalent chromium, column adsorption, batch process, column process.
1.INTRODUCTION Water being the significant resources of the biosphere as used in day today life, where after use the water is polluted leading to water contamination. Now this is a grave problem, in which wastewater comprising heavy metals continuously released into environment. In few ages, there is significantly upsurge in the ecological and global public health fear associated with aquatic pollution using these metals.
2. MATERIALS AND METHEDOLOGY The rice husk is a byproduct in rice mill. The rice husk is selected as one of the adsorbents for the removal of chromium. The rice husk is collected from the rice mill in Devadurga Raichur district. The sawdust is a byproduct of wood working operations in sawmill. The sawdust is also considered as adsorbent for the removal of chromium. The sawdust is collected from the sawmill in Devadurga Raichur district. Activated carbon is product from carbonaceous sources materials such as coconut, nutshells, coal and wood. All the chemicals used were analytical reagent grade.
Out of ninety metals, ten metals such as Ni, Co, Mn, Zn, Cr, Cu, Se, Ti, and Sb are prime public concern as per World Health organization (WHO). These metals are available from earth’s crust in very low concentration and found in their metallic, elemental form or chemical bounded with other inorganic materials like carbonate, sulphate, oxide or rock. Metal is considered as a one of the potential pollutants after dye, as it is lethal even at very low concentrations, last long effect, and
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