Nutrient balance for anaerobic co-digestion of tannery wastes: Energy efficiency, waste treatment and cost-saving

Simioni, Taysnara; Agustini, Caroline Borges; Dettmer, Aline; Gutterres, Mariliz

doi:10.1016/j.biortech.2020.123255

Cited by 19 publications

(8 citation statements)

References 32 publications

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“…The biogas production and methane yield obtained in this work were lower than that reported in other studies carried out with equivalent wastes, which produced up to 30 mL of biogas/g of VSS, with a methane percentage of 60% [22,24]. Comparing the wastes used in the studies cited above with that used in the present work, the main difference is in the composition of the sludge.…”

Section: No Oat Straw-slu + Shacontrasting

confidence: 78%

“…The concentrations of TKN and IC increased throughout the process (Table 4), as expected [24,29]. The increase in TKN concentration (+ 213.99%) is expected due to the natural characteristic of the waste, which, because of the animal hide origin, is a nitrogen-rich source.…”

Section: No Oat Straw-slu + Shasupporting

confidence: 63%

“…The ratio of sludge/shavings of 25 mL/1 g is equivalent, in proportion, to the amount of such waste generated by the tanneries of the region south of Brazil, according to local research [22]. A total of 200 mL of nutrient solution (2 g/L of yeast extract, 7 g/L of K 2 HPO 4 , and 3 g/L of KH 2 PO 4 ) was employed to ensure favorable conditions for the growth and metabolism of the microorganisms [24]. The bioreactors were maintained at 35 °C (mesophilic temperature range) in a DL-CBE18L (DeLeo) bacterial culture oven.…”

Section: Biodigestion Testsmentioning

confidence: 99%

“…In addition to structural features, lignocellulosic wastes have a high carbon/nitrogen (C/N) ratio which limits its efficient use in AD processes for methane production [19]. For example, oat straw, the biomass used in this study, has a C/N ratio around 50, higher than the optimal range for AD (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30) [20]. To overcome this limitation, lignocellulosic biomass is often co-digested with nitrogen-rich feedstock, in order to maintain the optimum C/N ratio and increase the stability of the process [21].…”

Section: Introductionmentioning

confidence: 99%

“…The leather industry generates substantial quantities of nitrogen-rich solid waste [22] and could be a good option to balance the C/N ratio of AcoD with oat straw. Leather shavings and sludge from wastewater treatment plants (WWTP) are the main solid wastes generated by tanneries [23] and AD has become an attractive solution in the perspective of sustainable and integrated management of these wastes [24,25]. Additionally, the combination of co-substrates results in other positive effects to the system, such as a better balance (pH, moisture), dilution of potentially toxic compounds, and supplementation of trace elements.…”

Section: Introductionmentioning

confidence: 99%

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Anaerobic Co-Digestion of Tannery Wastes and Untreated/Pretreated Oat Straw

et al. 2021

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The combination of carbon and nitrogen-rich co-substrates results in a better balance and increases the stability of the anaerobic co-digestion (AcoD) process. In this work, the AcoD process of waste from the leather industry (shavings and sludge) with waste from agriculture (oat straw) was assessed with regard to the energy (biogas production) and waste treatment efficiency (reduction of organic matter). The results indicate that the addition of untreated oat straw improved the AcoD process, increasing biogas production (25.44 mL of cumulative biogas/g of VSS added) by almost 60% when compared to the AcoD of only leather waste (16.17 mL/gVSS). Also, the effect of acid, alkaline, thermal, and the combination of these pretreatment techniques was evaluated on the lignocellulosic composition of oat straw and on methane yields. Pretreatments improved the characteristics and bioavailability of oat straw, particularly in methodologies that use alkali, with a significant increase in cellulose content accompanied by a decrease in hemicellulose and lignin content. However, the possible formation of secondary products or sterilization of important microorganisms did not reflect in a greater production of biogas: 21.06 mL/gVSS for oat straw pretreated only with HCl and 21.91 mL/gVSS for oat straw pretreated with HCl in autoclave; 5.20 mL/gVSS for oat straw pretreated with NaOH; and 3.43 mL/gVSS for oat straw pretreated with NaOH in autoclave; thermal pretreatment probably has generated toxic compounds from hemicellulose and cellulose degradation, which inhibited the AcoD process and, as consequence, virtually no biogas was produced.

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Section: No Oat Straw-slu + Shacontrasting

confidence: 78%

Section: No Oat Straw-slu + Shasupporting

confidence: 63%