Dual biogas/biochar production from anaerobic co-digestion of petrochemical and domestic wastewater: a techno-economic and sustainable approach

Abstract

This study investigates the utilization of petrochemical and domestic wastewater (PCW and DW) for dual biogas and biochar production, focusing on the economic and sustainable development criteria. Biogas yield by anaerobic co-digestion of a 0:1 (PCW:DW) feed was 306.4±11.8 mL per g chemical oxygen demand (COD) removed, which dropped by 12.7% with changing PCW:DW to 1:0. The results indicated that increasing the DW fraction in the feed encouraged the conversion of COD into more biogas and sludge amounts. The anaerobic sludge was subjected to pyrolysis to generate biochar with a yield of 0.6 g/g dry sludge. The delivered biochar showed appropriate surface morphology, elemental composition, physical properties, and surface functional groups, as demonstrated by SEM/EDX, XRD, and FTIR characterizations. The COD mass balance estimation of the anaerobic digestion system, with biochar yield, was used to determine the economic feasibility of treating 30 m3/day of wastewater. The 1:0 (PCW:DW) condition provided the most feasible scenario, with profits of 3340, 192, and 2819 USD/year for energy income, biochar selling, and pollution reduction, respectively. This economic benefit was equivalent to a payback period of 5.38 years. The fulfillment of multiple sustainable development goals (SDGs) related to clean and renewable energy production, human health protection, and economic growth was highlighted. Graphical abstract

Effect of Biochar on Anaerobic Co-Digestion of Untreated Sewage Sludge with Municipal Organic Waste under Mesophilic Conditions

“…It is associated with the hydrogen vibration of the hydroxyl groups of alcohols, phenols, organic acids, or by amides (present in proteins and peptides) [62,63]. The intensity of this peak was maintained in the uncarbonized and carbonized biomass, which could indicate that the hydroxyl groups did not decompose after the thermochemical process at high temperatures [64] pikes 2950-2800 cm −1 correspond to aliphatic stretching (CH groups). This stretch was found in biochar and feedstock.…”

“…This stretch was found in biochar and feedstock. However, the literature suggests that the gasification process can undo the aliphatic structure of the biomass [62,[64][65][66].…”

Bridging sustainability and industry through resourceful utilization of pea pods- A focus on diverse industrial applications

“…Biochar has significant potential in the remediation of pollutants from wastewater due to its unique physicochemical properties, including enriched surface functional groups (such as C − O, C O, COOH, and OH), a high specific surface area, pore structures, and cationic exchange capacity, all of which are beneficial for carbon sequestration ( Atukunda, Ibrahim, Fujii, Ookawara, & Nasr, 2022 ). Biochars remove contaminants from wastewaters through various mechanisms such as precipitation, surface complexation, ion exchange, pore filling, and electrostatic interactions.…”

Valorization of Textile Sludge and Cattle Manure Wastes into Fuel Pellets and the Assessment of Their Combustion Characteristics

“…9−11 Most of the conducted studies on TWS were on anaerobic digestion alone and/or in combination with other organic substrates, i.e., biogas production and nutrient-rich fertilizers for agriculture. 12,13 However, persistent heavy metals, dyes, and other chemical compounds in TWS are major constraints for its biological treatments, i.e., digestion, composting, and other thermal treatments, i.e., pyrolysis and incineration. 14−17 The direct combustion performance of TWS is weak due to the high content of inorganic materials, and for a similar reason, its heat content is poor.…”

“…Realizing the rich nutrient and carbon content in TWS, many researchers have investigated various methods, namely, anaerobic digestion, incineration, composting, pyrolysis, cocombustion, advanced oxidation, and blending with concrete. The mentioned methods/treatments were explored to produce renewable biogas, char, compost manure, bricks, fuel materials, and mineralization of their organic components. − Most of the conducted studies on TWS were on anaerobic digestion alone and/or in combination with other organic substrates, i.e., biogas production and nutrient-rich fertilizers for agriculture. , However, persistent heavy metals, dyes, and other chemical compounds in TWS are major constraints for its biological treatments, i.e., digestion, composting, and other thermal treatments, i.e., pyrolysis and incineration. − The direct combustion performance of TWS is weak due to the high content of inorganic materials, and for a similar reason, its heat content is poor. Moreover, studies on combustion/cocombustion performance and dynamics revealed the release of volatile organics in the medium temperature range of 200–300 °C and then unsustained combustion at higher temperature ranges due to significant inert/inorganic content. , Moreover, the cocombustion of TWS is an area that needs to be further explored, as TWS has a low heat calorific value and high volatile content, which could be optimized by compositing with other organic substrates (potential waste materials) to reduce the problems related to the low combustion efficiency of TWS and also help in solid waste reduction, detoxification, and energy recovery.…”