Biomethane production improvement by enzymatic pre-treatments and enhancers of sewage sludge anaerobic digestion

Abstract

Enzymatic hydrolysis is recognised as an effective pre-treatment for increasing biodegradability of sludge. In this work, isolated commercial enzymes as well as in-situ enzymes producer bacteria were used respectively as enhancers and pre-treatments of sewage sludge. Biodegradability of sample as well as biomethane potential production were studied. Results showed that depuration efficiencies in terms of CODs (73.5-85.5 %) and TVS (28.5-42.7 %) were more than twice the control value. In addition, pretreated samples as well as enhanced samples with enzymes generated more biomethane than control. The optimal ones, were those with the isolated proteases (P) and with bacteria (Bacillus licheniformis) treatment in-situ (F), producing a total volume of 72.4 ± 2.62 ml CH4 and 114 ml ± 0.46 CH4, respectively, increasing the biogas volume in 3.65 and 5.77 times respectively compared with control.

First approaches to valorizate fat, oil and grease (FOG) as anaerobic co-substrate with slaughterhouse wastewater: Biomethane potential, settling capacity and microbial dynamics.

“…All BMP bottles (including control test), were incubated in an optic IVYMEN system orbital shaking incubator from COMECTA Model D-2102 (at 45 rpm) and at mesophilic temperature. Inoculum:substrate (I:S) ratio was 2:3 v/v which correspond to 40% of inoculum, as it has been successfully previously considered optimum for biogas production and substrates acclimatization for Slaughterhouse residues (Agabo-García et al, 2019). In terms of TVS(g), I:S corresponded to 0.6; 0.56; 0.44 and 0.26 which is in the same order that those used in previous research using FOG as co-substrate (Martínez et al, 2012).…”

Anaerobic co-digestion of pre-treated press mud and Molasses-based distillery wastewater enhanced biogas production

“…Distillery effluent is another waste from the bioethanol/sugar industry that can cause environmental concerns when discharged in bodies of water especially with its characteristic unpleasant odor. It also has low pH values and high biochemical oxygen demand (13,414-87,700 mg/L) and chemical oxygen demand (32,000-109,700 mg/L) [26]. Press mud requires water or liquid waste for digestion; hence, distillery effluent can be used as co-substrate since it also has potential in balancing the macronutrients (i.e.…”

A GIS-Based Model to Assess the Potential of Wastewater Treatment Plants for Enhancing Bioenergy Production within the Context of the Water–Energy Nexus

“…To date, extensive works have been undertaken in evaluating substrate types, operating parameters and pretreatment methods on the process performance of AD process [25,[30][31][32][33]. Recent successes in full-scale AcoD implementation demonstrate the potential role of WWTPs as energy producers [34].…”