Composting of tannery waste with cow manure and rice bran

Abstract

The tannery waste contain utilizable nutrients and toxic organic compound which might affect soil processes and plants growth, and pathogens which might pose a threat to the local environmental communities. The study was designed to investigate the development of tannery waste collected from Unique leather finishing company Sharada, Kano, Nigeria, to compost Cow manure and Rice bran. Tannery waste was composted with cow manure and rice brand for sixty (60) days to reduce pathogens and toxic organic compounds. The compost was characterized by electric conductivity (EC) of 10.11µs/cm, pH of 7.62 and Carbon-Nitrogen (C: N) ratio of 28.8. The total concentration of Chromium, Lead, Cadmium, Copper, Zinc and Iron as mg/kg were 57.2, 0.92, 12.50, 60.50, 13.60 and 1101.00 respectively. No Salmonella sp. and Shigella sp. were detected in the compost, however, total bacterial counts decrease from 8.2 x108 cfu/g to 1.8 x106 cfu/g, the compost characteristics indicated that it was mature, and the germination index of the beans seed was 80% which may suggest the removal of most of the phototoxic compound. Key words; Composting, Heavy metals, Organic matter changes, Pathogens, Tannery wastes,