Abstract

In order to make effective use of cattle hair from a de-hairing process with hair-saving methods during the process of cleaner production in leather industry, complex oxidising materials (ammonium persulfate and hydrogen peroxide) were employed to oxidise and change the colour, structure of waste cattle hair. Then, sodium hydroxide and sodium bisulfite were employed to hydrolyse the de-coloured and de-structured cattle hair. The cattle hair hydrolysate was concentrated and was further fermented using a compound enzyme (neutral protease and pancreatin) so as to make it into an organic fertiliser.

Comparing the colour and the structure of the cattle hair, the best conditions of the reaction temperature, the dosage of ammonium persulfate and hydrogen peroxide solution and reaction time for 20g dried cattle hair were confirmed to be 75°C, 4g, 9g and 60 minutes. when the dosage of sodium hydroxide, sodium bisulfite, and reaction time were 8g, 2g and 45 minutes, the hydrolysis rate of the cattle hair and the content of the cattle hair hydrolysate was 95.4% and 17.6%. The solids content of the concentrated cattle hair hydrolysate is 30.8%. when the fermenting conditions are those of 0.15% neutral protease, 0.15% pancreatin and 3 hours, the nitrogen content of the fermented liquid is 338.5mg/L and was prepared as an organic fertiliser that contributes to the growth of plants, which can realise the utilisation of waste cattle hair from the leather industry.