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The impact and mechanism of fluoranthene (Flr), a typical polycyclic aromatic hydrocarbon highly detected in sludge, on alkaline fermentation for volatile fatty acids (VFAs) recovery and antibiotic resistance genes (ARGs) transfer were studied. The results demonstrated that VFAs production increased from 2189 to 4272 mg COD/L with a simultaneous reduction of ARGs with Flr. The hydrolytic enzymes and genes related to glucose and amino acid metabolism were provoked. Also, Flr benefited for the enrichment of hydrolytic-acidifying consortia (i.e., Parabacteroides and Alkalibaculum) while reduced VFAs consumers (i.e., Rubrivivax) and ARGs potential hosts (i.e., Rubrivivax and Pseudomonas). Metagenomic analysis indicated that the genes related to cell wall synthesis, biofilm formation and substrate transporters to maintain high VFAs-producer activities were upregulated. Moreover, cell functions of efflux pump and Type IV secretion system were suppressed to inhibit ARGs proliferation. This study provided intrinsic mechanisms of Flr-induced VFAs promotion and ARGs reduction during alkaline fermentation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Biohythane production through one-stage anaerobic digestion of sulfate-rich hydrolyzed tofu processing residue has been hampered by high H 2 S production. Herein, two-stage anaerobic digestion was investigated with the addition of molybdate (MoO 4 2- ; 0.24-3.63 g/L) and ferric chloride (FeCl 3 ; 0.025-5.4 g/L) to the dark fermentation stage (DF) to improve biohythane production. DF supplemented with 1.21 g/L MoO 4 2- increased hydrogen yield by 14.6% over the control (68.39 ml/g-VS fed ), while FeCl 3 had no effect. Furthermore, the maximum methane yields of methanogenic fermentation were 524.8 and 521.6 ml/g-VS fed with 3.63 g/L MoO 4 2- and 0.6 g/L FeCl 3 compared to 466.07 ml/g-VS fed of the control. The maximum yields of biohythane and energy were 796.7 ml/g-VS fed and 21.8 MJ/kg-VS fed with 0.6 g/L FeCl 3 when the sulfate removal efficiency was 66.7%, and H 2 S content was limited at 0.08%. Therefore, adding 0.6 g/L FeCl 3 is the most beneficial in improving energy recovery and sulfate removal with low H 2 S content., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Tofu processing residues (TPR) have received more attention as a source of bioenergy. However, their low solubility has hindered biohythane generation. Consequently, the ultrasonic and H 2 SO 4 pretreatments were combined and compared for the first time to improve the hydrolysis of organic matter and carbohydrate and increase free amino nitrogen generation from TPR. Besides, the impact of pretreatments on biohythane generation was investigated. Under the optimal conditions of 7.54% substrate level, 8% H 2 SO 4 concentration, 80 °C and 50 min, the coincident ultrasonic-H 2 SO 4 pretreatment enriched the contents of soluble chemical oxygen demand, reducing sugar, and free amino nitrogen to 49675 mg/L, 26 g/L, and 1721 mg/L, respectively, greater than individual pretreatments. Also, Biohythane yield increased by 4.24-13.61% over control (389.42 ± 23.7 ml/g-VS fed ). Furthermore, hydrogen yield at 42.5 ± 2.08 and 28.1 ± 1.07 ml/g-VS fed and sulfate removal efficiency at 93 and 92% were significantly improved with ultrasonic-H 2 SO 4 and H 2 SO 4 pretreatments, respectively, indicating acidogenic and sulfidogenic activity enhancement., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

This study aims to explore distinct bacterial strains from wood-feeding termites and to construct novel bacterial consortium for improving the methane yield during anaerobic digestion by degrading birchwood sawdust (BSD) and removing creosote (CRO) compounds simultaneously. A novel bacterial consortium CTB-4 which stands for the molecularly identified species Burkholderia sp., Xanthomonas sp., Shewanella sp., and Pseudomonas mosselii was successfully developed. The CTB-4 consortium showed high efficiency in the removal of naphthalene and phenol. It also revealed reduction in lignin, hemicellulose, and cellulose by 19.4, 52.5, and 76.8%, respectively. The main metabolites after the CRO degradation were acetic acid, succinate, pyruvate, and acetaldehyde. Pretreatment of treated BSD mixed with CRO enhanced the total methane yield (162 L/kg VS) by 82.7% and biomass reduction by 54.7% compared to the untreated substrate. CRO showed a toxicity decrease of >90%, suggesting the efficiency of constructed bacterial consortia in bioremediation and biofuel production., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The effect of hydrothermal pretreatment (HTP) of tofu residue (TR) and co-digestion of TR with hydrochar (HC) and a liquid fraction (LF) of hydrothermal pretreatment on biogas production was studied. The highest biogas and methane yield observed with the pretreated TR at HTP temperature of 140 °C reached 288 and 207 L/Kg VS, 24 and 37% above than the raw TR (control), respectively, and the highest content of methane 72%. Adding 4 g/L of HC (produced at 200 °C) enhanced the methane and biogas yield by 18 and 19% compared to untreated TR, respectively. It was found that HTP at temperature 140 °C and additive HC-200 (4 g/L) was the most efficient for biogas production from tofu residue and significantly reduced the digestion time needed from 20 to 10-13 days to reach 95% of biogas yield, which may result in substantial economic benefits., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Lignocellulose biodegradation is limited because of its recalcitrant structure particularly when polluted by toxic and carcinogenic compounds such as creosote oil (CRO). As far as we know, this might be the first report that explores the biodegradation of creosote treated wood (CTW) to serve biomethane production. Two novel CTW-degrading microbial consortia, designated as CTW-1 and CTW-2, were screened and constructed to enhance methane production from CRO-treated pine sawdust. After 12 days of biological pretreatment by CTW-1 and CTW-2, a significant reduction in lignocellulosic content of CTW was recorded; estimated as 49 and 43%, respectively. More than 64 and 91% of cumulative biogas and methane yields were obtained from biodegraded CTW over control. Ecotoxicity of treated and untreated CTW was compared by Microtox test. The biodegraded CTW hydrolysates showed a toxicity decrease of more than 80%, suggesting the promising role of constructed microbial consortia for biofuel production and bioremediation., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

This study might be the first to explore the novel constructed microbial consortia CS-5 and BC-4 for enhancing methane (CH 4 ) production during anaerobic digestion (AD) with simultaneous degradation of catalpa sawdust and chlorophenols (CPs). Significant reduction in cellulose, hemicellulose and lignin contents was achieved after the biodegradation of catalpa sawdust for 15 days by CS-5 and BC-4, with a total weight loss of 69.2 and 56.3%, respectively. The synergistic microbial consortia enhanced cumulative biogas and CH 4 yields by 76.3 and 64.3%, respectively higher than the corresponding control at the end of AD. More than 90% of CH 4 was produced within 18 days of AD as a result of microbial pretreatment of catalpa sawdust. These consortia resulted in remarkably higher energy conversion efficiency of 44.3% (218.1 L N CH 4 /kg TS) over the control. CS-5 and BC-4 removed more than 69 and 77% of the total amount of CPs tested after 15 days., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The effect of different mixing ratios of fish processing waste (FPW) with a liquid fraction (LF) of hydrothermal carbonization (HTC) of bamboo residues on biogas and methane yield was investigated. The different mixing ratios (FPW + LF) and HTC temperature (200-280 °C) had significant effects on biogas and methane production. The anaerobic co-digestion of the various mixing ratio of FPW and LF of bamboo residues did not enhance the methane yield compared to the AD of FPW alone. However, a mixture of 75FPW + 25LF(2 2 0) presented a comparable methane production (133 mL/g VS) to that achieved with 100FPW (142 mL/g VS), which represents an increase of only 6.4%. The ratio of 75FPW + 25LF(2 2 0) increased the biogas yield by 81% compared to the control group of 100LF(2 2 0). The mixing ratio of 75 FPW + 25LF(2 2 0) did not require clean water input to dilute FPW for biogas production and can be a practical waste management method., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The effect of hydrothermal carbonization (HTC) temperature and bamboo hydrochar (BHC) addition on biogas production in anaerobic digestion of fish processing waste (FPW) was studied. HTC temperature (200-280 °C) had significant effects on methane yield and content, but the BHC had little effects. The maximum biogas yield observed with HTC at 200 °C and a BHC adding ratio of 1:2 (dry mass ratio of FPW to BHC) reached 292 L/kg volatile solids (VS), which were 64% higher than the control group with only FPW, with the maximum methane yield of 219 L/kg-VS and highest net methane energy yield of 3410 kJ/kg-VS. The obtained results can be used to design an efficient anaerobic digestion process for treating and effectively utilizing fish processing waste., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The effect of hydrothermal (HTP) and Ca(OH) 2 pretreatments on the biogas produced by the anaerobic digestion of sugarcane bagasse (SCB) was studied. HTP, Ca(OH) 2 and combination pretreatment had significant effects on hemicellulose and lignin degradation during pretreatment and methane yield through digestion. The highest biogas production observed in combination pretreatment HTP 180 + 8.5% of SCB reached 318 mL/g Volatile Solids (VS), which were 47% higher than the untreated SCB, with the highest methane content 69% and highest lignin degradation 44%. The functional groups and the structural changes in the pretreated SCB have also been analyzed by Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) analysis. Kinetic analysis of methane production potential from SCB was determined to compare ultimate methane yields and kinetic constants. The results of this research contribute useful information to improve the efficiency of anaerobic digestion of SCB by pretreatment., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

In this study, a novel approach was developed to prepare engineered hydrochar from KMnO 4 treated bamboo residues through hydrothermal carbonization. The hydrochar yields were within a specified range of 61.8-67.8% at 180 °C and 39.8-45.0% at 260 °C, respectively. The higher temperature led to the higher C content, lower H/C and O/C ratio, whereas the ash content increased with increasing KMnO 4 concentration, causing the increase of solid yield as well as the decrease of C content. Pseudo-second kinetic model was optimal to describe bamboo hydrochar's hygroscopic dynamic, and the engineered hydrochar produced at 260 °C and 1.0 wt% concentration obtained the better hydrophobicity of 0.82%. SEM-EDS and XRD analysis confirmed the existence of manganese carbonate on the surface of engineered hydrochar, from which we inferred the chemical complexation between KMnO 4 and hydrochar., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Rice straw was pretreated by different combinations of physical (milling) and biological (incubation with Pleurotus ostreatus fungus) treatment to improve its biodegradability and biogas production during solid-state anaerobic digestion (SS-AD). Effects of milling (⩽2mm) and incubation time (10, 20 and 30d), on lignin, cellulose, and hemicellulose degradation during fungal pretreatment and methane yield during digestion were assessed by comparison with untreated rice straw. Both incubation time and milling had significant impacts on both lignin removal during fungal pre-treatment and methane yield during digestion. A combination of fungal pretreatment at 30days followed by milling prior to anaerobic digestion resulted in 30.4% lignin removal, the highest selectivity value (the ratio between relative lignin removal and relative cellulose removal) of 4.22, and the highest methane yield of 258L/kgVS. This was equivalent to a 165% increase in methane yield from SS-AD compared to untreated rice straw., (Copyright © 2016 Elsevier Ltd. All rights reserved.)