Bioplastic production using wood mill effluents as feedstock

Abstract

Fibreboard production is one of the most important industrial activities in Galicia (Spain). Great amounts of wastewater are generated, with properties depending on the type of wood, treatment process, final product and water reusing, among others. These effluents are characterized by a high chemical oxygen demand, low pH and nutrients limitation. Although anaerobic digestion is one of the most suitable processes for the treatment, lately bioplastics production (mainly polyhydroxyalkanoates) from wastewaters with mixed cultures is being evaluated. Substrate requirements for these processes consist of high organic matter content and low nutrient concentration. Therefore, wood mill effluents could be a suitable feedstock. In this work, the possibility of producing bioplastics from to wood mill effluents is evaluated. First, wood mill effluent was converted to volatile fatty acids in an acidogenic reactor operated at two different hydraulic retention times of 1 and 1.5 d. The acidification percentage obtained was 37% and 42%, respectively. Then, aerobic batch assays were performed using fermented wood mill effluents obtained at different hydraulic retention times. Assays were developed using different cultures as inoculums. The maximum storage yield of 0.57 Cmmol/Cmmol was obtained when when the culture was enriched on a synthetic media.

Waste to resource: Converting paper mill wastewater to bioplastic

“…The acidification efficiency of that waste stream was 37%. Ben et al (2011) obtained similar acidification efficiency from wood mill effluents (37e42%). As expected, the subsequent PHA content was low (25e29% of VSS).…”

“…Butyrate and acetate were the two dominant VFAs after acidification, which is similar to the results reported by Bengtsson et al (2008a) when acidifying paper mill wastewater. Besides acidifying paper mill wastewater, the result of other agroindustrial wastewater acidification have also been reported (Albuquerque et al, 2007;Ben et al, 2011;Coats et al, 2011;Dionisi et al, 2005;Morgan-Sagastume et al, 2010;Reddy and Mohan, 2012). Acetate was generally reported as the most abundant fermentation product.…”

“…Wastewater type f VFA Max PHA content Albuquerque et al, 2007 Sugar cane molasses 85% >30% Albuquerque et al, 2010 Sugar cane molasses 75% 75% Albuquerque et al, 2011 Sugar cane molasses ND 56% Ben et al, 2011 Wood mill 37e42% 29% Whey 84e97% ND Bengtsson et al, 2008a Paper mill 75e100% ND Pulp mill 55% ND Bengtsson et al, 2008c Paper mill 74% 42% Bengtsson et al, 2008b Paper mill 74% 48% Bengtsson et al, 2010 Sugar cane molasses ND 37% Dionisi et al, 2005 Olive oil mill 22e44% 55% Mato et al, 2010 Wood w a t e r r e s e a r c h 4 6 ( 2 0 1 2 ) 5 5 1 7 e5 5 3 0…”

“…Due to the encouraging preliminary results, several investigations have focused on using agro-industrial waste streams instead of artificial substrates for PHA production (Albuquerque et al, 2007(Albuquerque et al, , 2010(Albuquerque et al, , 2011Ben et al, 2011;Bengtsson et al, 2008bBengtsson et al, ,c, 2010Coats et al, 2007;Dionisi et al, 2005). The feasibility of producing bioplastics from the effluent of sugar factories, oil mills, wood mills, paper mills or municipal wastes has been studied.…”

Optimization of polyhydroxyalkanoate storage using mixed cultures and brewery wastewater

“…A wide range of substrates can be found within the wastes and/or wastewaters studied for PHA production. They include molasses (a by‐product of sugar production), urban wastewater, olive oil mill effluents, paper mill effluents, wood mill effluents, palm oil mill effluents and waste carbon . So far, brewery wastewater has not been used for PHA production using a system under aerobic dynamic feeding conditions.…”