Anaerobic biological degradation of protein hydrolysate cross-linked with higher-molecular weight diepoxides

Abstract

This work focuses on the influence of cross-linking with higher-molecular glycol diepoxides (and glycerol triglycidyleter) on biologic anaerobic degradation of protein hydrolysate (trade name Hykol) produced from chrome-tanned wastes (shavings). Samples of Hykol cross-linked with selected higher-molecular diepoxides were degraded with anaerobic sludge from a municipal plant at concentrations, in which organic carbon in samples in test bottles was approx. 200 mg/L, dry matter (inoculum) was 4.5g/L, temperature 35°C. Biodegradation of tested modified hydrolysate samples produced recorded quantities of biogas (CH4, CO2). Anaerobic degradation rate of the samples was least reduced when polyethylene glycol (600) diglycidyl ether was employed as the cross-linking agent, and most reduced when glycerol triglycidyl ether was applied. Attention was also given to preparation, the determination of solubility, intrinsic viscosity and IR spectra of prepared samples. In comparison with Hykol the degree of degradation decreased approx. from 70-50%. These modified hydrolysates were studied as materials which have the potential to be used as good biodegradable films, e.g. for agricultural applications.