Quick Release Nitrogenous Fertilizer from Human Hair

Abstract

Liquid nitrogenous fertilizer was synthesized using waste human hair as the raw material. Potassium hydroxide (KOH) and Tetramethylammonium hydroxide (TMAH) were used as the non-recoverable solvents for diffusion controlled reductive cleavage of hair protein. Performance of these solvents was analyzed and compared both individually and for different combinations. Experiments showed that KOH was better for dissolving hair and extraction of nitrogen in the forms of ammonium and nitrate ions compared to TMAH. Thereafter a vegetation pot experiment was established to investigate the performance of the produced liquid fertilizers compared to the commercial Nitrogen-Phosphorus-Potassium, NPK (15-15-15), fertilizer on the growth and yield of a short cycle crop, spinach (Spinacia oleracea L). The study design consisted of four treatments viz. no fertilization (T1), KOH based liquid fertilizer from human hair (T2), TMAH based liquid fertilizer from human hair (T3) and commercial NPK (T4). Each treatment had four replicate pots and was also done in parallel. The different treatments were added to the pot based on the total nitrogen requirement of 50 kg/ha for the spinach following broadcasting method. Plant physiology including plant height, number of the leaves, fresh and dry weight of the edible part of the harvested plant after 28 days suggested that the performance of the synthesized fertilizers as a nitrogen source were better than the commercial NPK fertilizer. These outcomes encourage such novel use of waste human hair.