Nano-Biochar as a Sustainable Catalyst for Anaerobic Digestion: A Synergetic Closed-Loop Approach

Abstract

Nowadays, the valorization of organic wastes using various carbon-capturing technologies is a prime research area. The anaerobic digestion (AD) technology is gaining much consideration in this regard that simultaneously deals with waste valorization and bioenergy production sustainably. Biochar, a well-recognized carbonaceous pyrogenic material and possessing a broad range of inherent physical and chemical properties, has diverse applications in the fields of agriculture, health-care, sensing, catalysis, carbon capture, the environment and energy. The nano-biochar-amended anaerobic digestion approach has intensively been explored for the past few years. However, an inclusive study of multi-functional roles of biochar and the mechanism involved for enhancing the biogas production via the AD process still need to be evaluated. The present review inspects the significant role of biochar addition and the kinetics involved, further focusing on the limitations, perspectives, and challenges of the technology. Additionally, the techno-economic analysis and life-cycle assessment of biochar-aided AD process for the closed-loop integration of biochar and AD and possible improvement practices are discussed.

Pyrolyzed biomass-derived nanoparticles: a review of surface chemistry, contaminant mobility, and future research avenues to fill the gaps

“…FTIR spectroscopy data show that, as compared to their parent biochar, PBNPs have higher abundances of C–O–C, aliphatic –OH, phenolic –OH, quinoid C=O (Liu et al 2018 ; Goswami et al 2022 ) and COOH groups (Song et al 2019 ), which provides evidence that there are more oxygen containing functional groups on PBNPs than bulk biochar (Fig. 3 ).…”

“…Since PBNPs host appreciably higher densities of oxygen-bearing functional groups than their parent biochar, PBNPs have a high capacity to sorb inorganics, making them a potential replacement for costlier sorbents, such as activated carbon, in the remediation of wastewater contaminated with toxic heavy metal cations (Fu and Wang 2011 ). Much of PBNPs electron-donating capacity (EDC) is a result of the increased concentration of phenolic surface functional groups (Goswami et al 2022 ). Qian et al ( 2016 ) studied the removal of Cr(VI) and As(III) by PBNPs extracted by sonication of pyrolyzed rice straw.…”

“…Interestingly, besides acting as a reducing agent, PBNPs can serve as an oxidant, similar to natural dissolved organic matter (Redman et al 2002 ). The electron accepting capacity of PBNPs is commonly attributed to the presence of quinoid functional groups (Goswami et al 2022 ). Dong et al ( 2014 ) observed that oxidation of As(III), at an initial concentration of 10 mg L −1 , increased from negligible to more than 20% at pH 10 by adding PBNPs in both ice and aqueous phases.…”

Enhancement of Anaerobic Digestion with Nanomaterials: A Mini Review

“…Graphene oxide Biogas and methane increase Batch, cumulative methane yield was highly dependent on the dosage [25] Nano-biochar Biogas and methane increase Batch, review focused mainly on biochar [26] Graphene Biogas and methane increase Batch, low temperature did not affect archaeal community compositions with graphene and methane increase [27] Carbon nanotubes Biogas and methane increase; mitigation of ammonia inhibition Batch, carbon nanotubes may mitigate or worsen the ammonia inhibition depending on the total ammonia nitrogen [28] Graphite, graphene and graphene oxide Biogas and methane increase Batch, graphene exhibited the best performance by removing some antibiotic resistance genes [29] Graphene Biogas and methane increase Batch, direct interspecies electron transfer (DIET) via graphene was established [30] The distribution of the tables was performed according to the materials used: Table 1 compiles the works that used inorganic metallic NPs, whereas Table 2 shows the works carried out with other nanomaterials.…”

Nanomaterial-Based Therapy for Wound Healing

“…Presently, novel nanomaterial-based bandages, such as hydrogels, nanofibers, and films, are now being extensively utilized. Interestingly, by 2021, the market for such materials is predicted to surpass USD 20.4 billion globally [8,9].…”