Acidic pretreatment of cellulose for bio methane production

Present work deals with the exhaustive investigations of rapid de-lignification processes from source-sorted organic fractions that are recalcitrant in nature. Organic solid wastes (OSW) belong to the organic fraction of municipal solid wastes (MSW) and they act as enormous potential substrate for alternative source of energy in the form of bio-fuels. Nevertheless, these substrates are not easily biodegradable and the degree of biodegradability is solely dependent on the composition and characteristic of organic solid wastes in municipal solid wastes. The component responsible for recalcitrance of organic solid wastes is lignin that occurs in variable amounts in different plant residues. In order to remove the recalcitrance from organic fraction municipal solid wastes and to make it more easily degradable by microbial groups, certain pretreatment techniques have been adopted and they are applied either individually or in combined way for enhancement of anaerobic digestion (AD) process. The present work studied the effect of acid treatment with acetic acid on the used substrate, evaluated its effectiveness on biogas production, and studied the concentrations of CH4 and CO2 during the fermentation period, which amounted to 90 days. All results are presented in clear curves for the purpose of facilitating the study.

Effects of Onion Residue, Bovine Manure Compost and Compost Tea on Soils and on the Agroecological Production of Onions

Organic solid wastes are rarely considered when planning for rural production in Argentina. Onion production in the low valley of Río Colorado (Buenos Aires) generates between 12,000 and 20,000 Mg year−1 of vegetal wastes (i.e., leaves, stems, skins, roots) from harvesting, cleaning and classification of bulbs, causing many problems with their management. The aim of this work is to study the effect of different doses of onion residue-bovine manure compost and onion residue-bovine manure compost tea on the soil physicochemical properties, microbial activity and agroecological onion production in sandy soil. Results showed that the highest dose of compost caused the highest effects on soil pH, electrical conductivity and nutrient content. Soil enzymatic activities were already high in the soil before the compost was applied, which may have contributed to the small effect caused by any dose on soil activity. A significant positive effect on bulb weight and organic onion yield were found as a result of the amendment and growing season. In conclusion, agroecological production of onion with the addition of a 300 kg N ha−1 compost and compost tea guarantee yields comparable to those of conventional fertilization, as occurred during the two growing seasons of this study.