Isolation of Sludge Protein from Skin Fleshing Wastes by Alkaline Hydrolysis and Determining its Effects as a Fertilizer on Growth of Some Nursery Plants: A Step Towards Tanneries Waste Utilization in Pakistan

During Leather Processing, Skin Fleshing Wastes (SFW) are usually disposed of in an open area which creates toxic hazards. In this study, (SFW) from tanneries have been hydrolyzed using two alkalis Potassium hydroxide ( 2g/ 100g of SFW ) and Sodium hydroxide ( 4g/100g of SFW) with a sufficient amount of water at 2300 F in Autoclave for two hours. Three resultant fractions fats and oil (approximately 240 g Kg-1 ), protein (approximately 554 g Kg-1 ) and sludge containing a high amount of ashes (approximately 900 g Kg-1 ) were successfully isolated respectively. The yield of fractions was calculated on the wet weight of SFW used after the removal of lime using ammonium sulphate. In this study, the isolated third fraction Fleshing Sludge (FS) from the hydrolyzed fleshing wastes used fertilizer on the six different plants on growth commonly named Ghobi, Cran Dola, Patunia, Placus, Dentist and Dalia. The observations were taken during 30 days of incubation, at the usual temperature. The application of FS in plants observed that growth was enhanced in significant proportion as compare to reference plants supplemented with commercial fertilizer except in the Ghobi sample PS1 which shows some phytotoxicity confirmed by leaf yellowing. The results revealed that the applied sludge has no adverse effect on the growth of other experimental plants. Results were taken by measuring plants according to standard methods