Grey Water Treatment using Corncob

Corncob which is a biopolymer waste which represent an interesting alternative as a low cost adsorbent because of its abundant, renewable and biodegradable raw resource and properties such as its chemical stability, oil absorption, surface area, iodine value and high reactivity, resulting from the presence of chemically reactive hydroxyl groups. This project deals with the filtration of waste water using corncobs which are generally used as fuel which creates air pollution and global warming. Corncobs are one of the most plentiful and important agricultural wastes in maize cultivation. This project discusses about low cost water filtration by bio-sorption mechanism using corncobs as filter material in its various forms. The different layers of corncob are separated, granulated and surface activated by suitable treatment with 0.5 N phosphoric acid and citric acid. Also activated carbon is prepared from the corncobs and impregnated in 1N NaOH to increase the pore size and free covalent bonds by removing the organic adsorbates and unwanted impurities. Diatomaceous earth which is a naturally occurring soft, siliceous sedimentary rock that is easily crumbled into fine off-white powder is used as a filtration aid to filter very fine particles and bacteria that would otherwise pass through. The outcome of the project shows satisfactory removal of solids, hardness, chlorides, turbidity, BOD with an average efficiency of 75% and excellent removal of heavy metal concentration especially 90% of Chromium (VI). However the performance over COD is unsatisfactory and change in pH is negligible as it remains in acidic range as the influent.