Anaerobic biodegradation of polyvinyl alcohol modified by extracellular polysaccharides

Abstract

Práce se zabývá ananaerobní biodegradací směsí glycerolem plastifikovaného polyvinylalkoholu s biopolymery (škrob, gellan, xanthan) ve vodném prostředí za ananaerobních podmínek po inokulaci městským čistírenským kalem. Biodegradace glycerolu a polysacharidů dosahovala 95 % a více, polyvinylalkoholu pouze 6,5 % i po 500 hod. Průběh biodegradace byl sledován z bilance uhlíku uvolněného do plynné fáze. Polysacharidy zlepšují biodegradaci, ale zhoršují mechanické vlastnosti směsí.

This work focused on anaerobic biodegradation of blends composed of glycerol-plasticized polyvinyl alcohol (PVA) and biopolymer (starch, gellan, xanthan) in an aqueous environment, after inoculation with digested activated sludge from a municipal wastewater treatment plant. Glycerol degradability is comparable to degradability of used modifying agents. Modifying agents added in the 20?40 wt % range proportionally increased biodegradation degree (Dt) calculated from balance of transformed carbon in the system. Biodegradation degree of polysaccharides and glycerol attained 95 % and over. For PVA it was only 6.5 % (in breakdown times up to 500 hours). Content of polysaccharides favorably affects biodegradation degree of polyvinyl alcohol blends, but at the expense of reduced mechanical properties of resultant products.