Physico-chemical pretreatment and fungal biotreatment for park wastes and cattle dung for biogas production

Abstract

With the rising demand for renewable energy and environmental protection, anaerobic digestion of biogas technology has attracted considerable attention within the scientific community. The effect of physico-chemical pretreatment on cellulose degradation followed by fungal treatment by Aspergillus terreus and Trichoderma viride to treat cellulosic biomass for enhancing its digestibility was investigated. The tested substrate was digested with and without physical, chemical, and biological treatment. Fresh leaves, dry leaves and cattle dung were characterized by a total solids content 35, 84 and 17 %, volatile solids content 81.2, 59.49 and 64.5 % and C/N ratio 31, 45.4 and 13.6, respectively. Biogas total volume was determined using water replacement technique, while methane volume was determined using precipitation of CO2 in 20 % NaOH solution. Pretreatment steps were carried out by using mechanical and chemical pretreatments using 2.5 % NaOH mixed with 2.5 % NH4OH for 15 days, followed by biological treatment of A. terreus and T. viride. The potential of pretreatment of substrate was studied at regular intervals of 0, 7, 14, 21, 28, 35, 42, 49, 56, 63 and 70 days determining the change in chemical and physical compositions of used substrates. Biogas production was 102.6 and 125.9 L/KgVS from untreated and pretreated substrate, respectively. On the other hand, methane production was 61.4 and 79.8 L/KgVS from untreated and pretreated substrate, respectively. In conclusion, Physical (milling), chemical (NaOH and NH4OH) pretreatment in addition to fungal (A. terreus and T. viride) treatment for the tested substrate prior to AD was an efficient process for improvement of biogas and methane production.Electronic supplementary materialThe online version of this article (doi:10.1186/s40064-015-1466-9) contains supplementary material, which is available to authorized users.

Microorganisms and Enzymes Used in the Biological Pretreatment of the Substrate to Enhance Biogas Production: A Review

“…Ali and Sun [112] investigated the results of chemical and physical methods followed by fungal treatment by Aspergillus terreus and Trichoderma viride for park wastes and cattle dung in order to enhance the biogas generation. The authors concluded that the biogas production was improved (by 22.7%) by chemical and biological feedstock pretreatment (125.9 L/Kg VS) versus untreated feedstock (102.6 L/Kg VS).…”

Quantity and Quality of Biogas Produced from the Poultry Sludge Optimized by Filamentous Fungi

“…pH and temperature inside the reactor. Finally, it was observed that the methane fermentation process increased the pH of the post-fermentation mass relative to the batch substrates, as it was in the case in studies by Ali and Sun [29]. In own studies, the dry matter and organic dry matter contents in the resulting post-fermentation pulp were also reduced (Fig.…”

“…Increasing the methane yield in MIX combinations (by 28 %) and F1 (by 12 %) as compared to the control material may indicate a favorable effect of pretreatment of the material under study by the above-mentioned fungal strains variants. Ali and Sun [29] demonstrated that biological pretreatment using Aspergillus terreus and Trichoderma viride fungi as well as chemical pretreatment can remarkably accelerate degradation of lignocellulosic substrates used for methane fermentation and thus favorably affect the amount of biogas and methane obtained.…”

Growth of fungi on alternative substrates and fungal pre-treatment for biogas production

“…Methods for improving biogas production can be physico-chemical, microbiological or a combination (Ali and Sun, 2015). Microbiological methods include bioaugmentation with bacteria or fungi.…”

“…Fungi can degrade components that are not easily degradable for other living organisms by cellulolytic, hemicellulolytic, glycolytic, and proteolytic enzymes. Examples of fungi that have been used for pretreatment are Ceriporiopsis subvermispora, Auricularia auricula-judae, Trichoderma reesei, Ischnoderma resinosum and Fomitella fraxinea (Ali & Sun, 2015). Tuyen et al (2012) tested 11 whiterot fungi for their ability to degrade lignin and to improve fermentation of wheat straw in cow rumen, by measuring gas production.…”