Enzymatic processes soils, polymers

Biodegradability - Metabolix PHA offer hydrolytic stability under normal service conditions but when exposed to microbial organisms naturally present they break down enzymatically in soil, composting, waste treatment processes, river water and marine environments. They also rapidly decompose to carbon dioxide and water and will degrade in anaerobic environments, unlike some other biodegradable polymers. 

Waste-treatment processes commonly result in the production of solid wastes that must be disposed of safely. Enzymatic treatment is no exception. For example, although enzymatic treatment may not produce as large a quantity of solid products as does biological treatment, some solid residues may be formed, e.g., the polymer precipitates formed during the treatment of phenols with peroxidases, spent adsorbents such as talc, chitin, or activated carbon that are used to eliminate the soluble products of enzymatic reactions, or residues of plant materials such as raw soybean hulls when they are used in place of purified enzymes during treatment. Perhaps, the polymers and adsorbents could be incinerated to recover some energy if the emission of dangerous combustion by-products can be controlled or prevented. The residues of plant materials could potentially be composted and used as soil conditioners, provided that pollutants do not leach from them at substantial rates. To date, none of these disposal problems have been addressed adequately. 

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