Treatment of natural rubber latex serum waste by co digestion with macroalgae, Chaetomorpha sp. and Ulva intestinalis, for sustainable production of biogas
Biogas production is proposed as an alternative approach to using natural rubber Hevea brasiliensis latex serum, a major waste product from the production of concentrated latex. To make the most efficient use of the reactor size, the addition of macroalgal biomass as a co substrate to the fermentation system was investigated. The biogas yield of latex serum as a single substrate was (398 14) L per kg of volatile solids added (VSA) For the co digestion system, algae mixed with serum were investigated at wet mass ratios of Chaetomorpha sp. to Ulva intestinalis to serum at 3:0:1, 2:0:2, 1:0:3, 0:1:3, 0:2:2 and 0:3:1. Theco digestion system with latex serum at 2 to 3 out of 4 parts produced the highest biogas yields within the range of 422 460 L kg 1 of VSA. Other parameters such as carbon to nitrogen mass ratio, total solids content and initial pH value were investigated at the constant ratio of 1: 3 of Chaetomorpha sp. to latex serum, and the parameter settings of 15, 10.5 and 7, respectively, were close to optimal, with an (888 155) Lkg 1 of VSA cumulative gas yield. The methane yield of the optimised system over 45 days was (197 16) L kg 1 of VSA and the reduction in COD was (40 4) Latex serum, whether alone or co digested with algae in biogas production, appears to be promising for the management of waste in concentrated latex production.
Chemical Papers