Managing paper and pulp industry by-product waste utilizing sludge as a bio-fertilizer

Abstract

An enormous amount of waste material (sludge) generated from paper and pulp industries is either dumped or incinerated. However, this pulp is an enriched source of macronutrients and can be employed on agricultural land to improve its fertility. The current study was therefore performed to analyze phosphorus (P) and calcium (Ca) by flame photometer, nitrogen (N) by Kjeldahl method, and magnesium (Mg) by back titration from sludge. The application of sludge significantly increases macronutrients in the plants lady finger (Abelmoschus esculentus) and garden mint (Mentha sachalinensis).We applied primary (initial husk treatment) and secondary (after primary treatment) sludge to observe the growth of Abelmoschus esculentus and Mentha sachalinensis. However, primary sludge showed the highest concentration of nutrients, i.e., 96.5% P, 99.6% N, 86% Ca, and 0.008% Mg. The application of paper and pulp waste to the soil indicates that these bio-solids are good for soil fertility, biomass production, and plant growth; however, they are slightly less efficient than synthetic fertilizers. However, the synthetic fertilizers are probable candidates for holding heavy metals, so these bio-solids can be considered a better source for soil fertility.