Comprehensive Meta-Analysis of Pathways to Increase Biogas Production in the Textile Industry

Abstract

The textile industry is one of the largest environmental polluters in the world. Although waste management via anaerobic digestion (AD) is a sustainable strategy to transform waste into clean energy and water recovery, the efficiency of the AD process is reduced by the presence of recalcitrant materials, chemicals, and toxic contents. This study aims to investigate the performance of several chemical, physical, and biological pretreatments applied to improve the biodegradability of textile waste. We performed a meta-analysis with 117 data extracted from 13 published articles that evaluated the efficiency of pretreatments applied to textile waste prior to AD to increase biogas production measured as methane (CH4) yield. Even though the majority of the studies have focused on the effect of chemical and physical pretreatments, our results showed that the application of biological pretreatments are more efficient and eco-friendlier. Biological pretreatments can increase CH4 yield by up to 360% with lower environmental risk and lower operating costs, while producing clean energy and a cleaner waste stream. Biological pretreatments also avoid the addition of chemicals and favor the reuse of textile wastewater, decreasing the current demand for clean water and increasing resource circularity in the textile industry.

A review on evaluation of textile waste for ethanol extraction

“…The maximum theoretical yield of ethanol was 92% [67]. The technological process described by Anacleto et al [67], is shown schematically in Figure 4. In the following scientific articles [9,11,28,31,32,55,58,63,69, 71÷74] alkaline NaOH, NaOH/urea, NaOH/thiourea, NaOH/urea/thiourea solutions were used for pre-treatment of textile waste.…”

“…SSF method were applied to obtain ethanol [2, 55, 67÷70]. The technological process described by Anacleto et al [67] is as follows: (i) in the first step, the textile waste was subjected to a bleaching process in the presence of Na2S2O4 and Na2CO3 under thermal conditions; (ii) then, the bleached textile waste was subjected to the cellulose dissolution process in the presence of H3PO4; (iii) followed the textile waste regeneration process by washing with deionised water; (iv) the next step was to remove excess water (by centrifugation) from the regenerated textile waste, followed by washing with deionised water, which was carried out 3 times; (v) the filtration step followed, from which the resulting filtration solution was neutralized with NaOH and the regenerated textile waste was collected on filter paper; (vi) the next step was to remove the salt by washing the regenerated textile waste collected by the filter paper with water; (vii) in the last step, the wet pre-treated textile waste was subjected to the SSF process, in order to obtain ethanol. Enzymatic saccharification was carried out in the presence of cellulase, and fermentation in the presence of Zymomonas mobilis, yeast extract and the following mixture of chemicals: KH 2 PO 4 , (NH4)2HPO4 and MgSO4•7H2O.…”

“…Enzymatic saccharification was carried out in the presence of cellulase, and fermentation in the presence of Zymomonas mobilis, yeast extract and the following mixture of chemicals: KH 2 PO 4 , (NH4)2HPO4 and MgSO4•7H2O. The maximum theoretical yield of ethanol was 92% [67]. The technological process described by Anacleto et al [67], is shown schematically in Figure 4.…”

Nanotechnology boosts the production of clean energy via nanoparticle addition in anaerobic digestion

“…This process also deals with different groups of microorganisms that play crucial roles in AD (Deng et al, 2020) and the syntrophic relationship between these microorganisms, which have different growth requirements (Schnürer and Jarvis, 2018;Deng et al, 2020), is mandatory to achieve maximum biogas production (He et al, 2019). Thus, many strategies have been developed to improve microbial metabolic activities and biogas production in AD, such as co-digestion, pre-treatments and upgrades approaches (Patinvoh et al, 2017;Paritosh et al, 2018;Adnan et al, 2019;Abdelwahab et al, 2020;Anacleto et al, 2022).…”