Characterising Low Cost Agricultural by-product for Sequestering Greywater Pollutants by Biosorption for Reuse Application

Abstract

With the growing urbanization the imbalance between water supply and demand has become
significant so treating the grey water is an inevitable need of an hour. Household greywater
has been treated in order to reduce the load on treatment plant and enhance the reuse potential
of the same. Inaccessibility of surface water in some regions lead to excessive pumping from
ground water thus groundwater depletion has become a serious problem. This paper has
proposed a decentralized approach for treating greywater separately and detoxify it to the
extent where it can be reused for ground water recharging through constructed wetlands so
that both the problems can be addressed simultaneously. This treatment comprises
biosorption of COD, heavy metals, colour, traces of dyes, phosphorus, nitrogen, taste, odour
by using the combination of agricultural by-products such as: Apple peels, tomato peels,
banana peels, orange peels and bamboo charcoal. The agricultural waste is organic in nature
consisting of carbonyl, hydroxyl, acitamido, alcoholic, phenolic, amido, amino like functional
groups. Each group forms different complexes with pollutants and thus carries varying
affinity towards desired pollutant. The combination of different agricultural media with
bamboo charcoal has such selected that they lead up to 60- 65% reduction in COD, heavy
metal, colour, dye, taste whereas the nutrient such as phosphorus and nitrogen is up taken by
the wetlands application. The optimum pH of 3-3.5 offered by fruit peel media provides a
favourable condition for biomass growth and thus enhances the biosorption.