Heterogeneously Catalyzed Reductive Depolymerization of Lignin to Value-Added Chemicals.

Lignin is an abundant renewable source of aromatics, but its complex heterogeneous structure poses challenges for its depolymerization and valorization. Heterogeneously catalyzed reductive depolymerization (HCRD) has emerged as a promising approach, utilizing heterogeneous catalysts to facilitate selective bond cleavage in lignin and hydrogen transfer to stabilize the products under mild conditions. This review provides a comprehensive understanding of the hydrogen transfer mechanisms in HCRD, involving different hydrogen sources, including molecular hydrogen, alcohols, formic acid, etc.

Environmental sustainability assessment of a new food waste anaerobic digestion and pyrolysis hybridization system.

This research conducted an environmental life cycle assessment (LCA) to evaluate an anaerobic digestion-co-pyrolysis (ADCo-Py) system in which pyrolysis was added to traditional food waste (FW) anaerobic digestion (AD) systems to treat the solid fraction and impurities separated from FW. The solid fraction, including impurities such as wooden chopsticks, plastics, eggshells, and bones, is usually incinerated, while pyrolysis can be a viable alternative to optimize FW treatment. The environmental impact of ADCo-Py was compared with stand-alone AD, pyrolysis, and ADCo-INC (AD with incineration of separated solids).

Experimental study and techno-economic analysis of co-processing system for treatment of food waste with various impurities.

The study assessed a co-processing system segregating food waste (FW) with different impurities into liquid (slurry) and solid fractions and treated using anaerobic digestion (AD) and pyrolysis (Py), respectively, which is defined as ADCo-Py. Biomethane potential tests showed higher methane yield from the FW slurry fraction (572.88 mL/gVS) compared to the whole FW (294.

Microecological health assessment of water environment and sediment based on metagenomics: a case study of Guixi River in Chongqing, China.

River sediment is vital in containing water pollution and strengthening water remediation. This paper has conducted a study on the microecological health assessment of the sediment and water body of Guixi River in Dianjiang, Chongqing, China, using metagenomics sequencing and microbial biological integrity index (M-IBI) technology. The analysis of physical and chemical characteristics shows that the concentration of TN varies from 2.

Quantitative analysis of TCE biodegradation pathway in landfill cover utilizing continuous monitoring, droplet digital PCR and multi-omics sequencing technology.

The remediation of volatile chlorinated hydrocarbons in the quasi-vadose zone has become a significant challenge. We applied an integrated approach to assess the biodegradability of trichloroethylene to identify the biotransformation mechanism. The formation of the functional zone biochemical layer was assessed by analyzing the distribution of landfill gas, physical and chemical properties of cover soil, spatial-temporal variations of micro-ecology, biodegradability of landfill cover soil and distributional difference metabolic pathway.

Synergistic effects of vegetation and microorganisms on enhancing of biodegradation of landfill gas.

The uncontrolled release of landfill gas represents a significant hazard to both human health and ecological well-being. However, the synergistic interactions of vegetation and microorganisms can effectively mitigate this threat by removing pollutants. This study provides a comprehensive review of the current status of controlling landfill gas pollution through the process of revegetation in landfill cover.

Water microecology is affected by seasons but not sediments: A spatiotemporal dynamics survey of bacterial community composition in Lake Changshou-The largest artificial lake in southwest China.

This study aimed to evaluate the correlation between microecology of sediments and water as well as their spatial-temporal variations in Changshou Lake. The results demonstrated that microecology in the lake exhibits spatiotemporal heterogeneity, and microbial diversity of sediments was significantly higher than that of water body. Further, it was found that there was statistically insignificant positive correlation between microecology of sediments and that of water body.

Effect mechanism of individual and combined salinity on the nitrogen removal yield of heterotrophic nitrification-aerobic denitrification bacteria.

One of the biggest challenges of applying heterotrophic nitrification-aerobic denitrification (HN-AD) bacteria to treat high salt organic wastewater lies in the inhibitory effect exerted by salinity. To study the inhibition effect and underlying mechanism induced by different ion types and ion composition, the individual and combined effects of NaCl, KCl and NaSO on HN-AD bacteria Acinetobacter sp. TAC-1 were systematically investigated by batch experiments.

Effects of different conditions tested "in vitro" on the phosphorus runoff potential of livestock manure.

This study aimed to investigate the changes of swine and dairy manure characteristics during a long-term storage (150-180 days) under 4 °C, 20 °C, and 37 °C, sealed and unsealed conditions. Water extractable phosphorus (WEP) of both manures rapidly increased during the first 15-30 days and then decreased. At the end of the storage, the WEP reduction was 90%±3% and 71%±5% of the initial concentration for swine manure and dairy manure, respectively.

Ecological risk assessment of toxic metal(loid)s for land application of sewage sludge in China.

Sewage sludge, including those after biological or thermochemical treatments, has the potential to be used as fertilizers for recycle of resources. However, its potential ecological risk is also of great concern to policy making. This study employed comprehensive ecological risk assessment (ERA) methods to evaluate the risk caused by the toxic metal(loid)s in sewage sludge throughout China.

Keystone taxa and functional analysis in arsenic and antimony co-contaminated rice terraces.

Both arsenic (As) and antimony (Sb) are primary environmental contaminants that often co-exist at contaminated sites. Though the microbial community compositions of As- and Sb-contaminated sites have been previously described, the changes in microbial community interactions and community functions remain elusive. In the current study, several key metabolic processes, such as As/Sb detoxification and carbon fixation, were enriched under heavily contaminated conditions.

Variation in the diazotrophic community in a vertical soil profile contaminated with antimony and arsenic.

A nitrogen (N) deficiency will usually hinder bioremediation efforts in mining-derived habitats such as occurring in mining regions. Diazotrophs can provide N to support the growth of plants and microorganisms in these environments. However, diazotrophic communities in mining areas have been not studied frequently and are more poorly understood than those in other environments, such as in agricultural soils or in the presence of legumes.

Synergistic Impacts of Arsenic and Antimony Co-contamination on Diazotrophic Communities.

Nitrogen (N) shortage poses a great challenge to the implementation of in situ bioremediation practices in mining-contaminated sites. Diazotrophs can fix atmospheric N into a bioavailable form to plants and microorganisms inhabiting adverse habitats. Increasing numbers of studies mainly focused on the diazotrophic communities in the agroecosystems, while those communities in mining areas are still not well understood.

Life cycle assessment of the integration of anaerobic digestion and pyrolysis for treatment of municipal solid waste.

The integration of anaerobic digestion (AD) and pyrolysis (Py) could be a solution to economically utilize the organic fraction of municipal solid waste (OFMSW). However, it is not clear whether the environmental impact of the integrated pathway always outperforms the two single technologies. In this study, two integrated pathways (AD-Py, Py-AD) were compared with single AD and Py from the life cycle environmental impacts point of view.

Structure and variation of root-associated bacterial communities of Cyperus rotundus L. in the contaminated soils around Pb/Zn mine sites.

Soil contamination due to mining activities is a great concern in China. Although the effects of mining pollution resulting in changes of soil characteristics and the microbiome have been documented, studies on the responses of plant root-associated microbial assemblages remain scarce. In this work, we collected bulk soil, rhizosphere soil, and root endosphere samples of Cyperus rotundus L (Cyp) plants from two Pb/Zn mines, of which, one was abandoned (SL) and the other was active (GD), to investigate the bacterial community responses across different site contamination levels and Cyp plant compartments.

Effects of antimony on anaerobic methane oxidization and microbial community in an antimony-contaminated paddy soil: A microcosm study.

Anaerobic methane oxidation (AOM) plays an important role in sinking global methane and thereby in constraining climate change. Anthropogenic activities in antimony (Sb) mines have resulted in Sb contamination in rice fields, which are among the dominant methane sources. However, the knowledge of effects of Sb on AOM in paddy soils and the microbiota involved in this process remains limited.

Arsenic and antimony co-contamination influences on soil microbial community composition and functions: Relevance to arsenic resistance and carbon, nitrogen, and sulfur cycling.

Microorganisms can mediate arsenic (As) and antimony (Sb) transformation and thus change the As and Sb toxicity and mobility. The influence of As and Sb on the innate microbiome has been extensively characterized. However, how microbial metabolic potentials are influenced by the As and Sb co-contamination is still ambiguous.

Investigation of the antimony fractions and indigenous microbiota in aerobic and anaerobic rice paddies.

The accumulation of antimony (Sb) by rice is a severe threat to exposed populations. Previous studies demonstrated that, compared to flooded (anaerobic) water management, dry cultivation management (aerobic) could substantially decrease As, an analog of Sb, uptake by rice. However, the effects of different water management strategies on the accumulation of Sb by rice are less understood.

Stable-isotope probing coupled with high-throughput sequencing reveals bacterial taxa capable of degrading aniline at three contaminated sites with contrasting pH.

The biodegradation of aniline is an important process related to the attenuation of aniline pollution at contaminated sites. Aniline contamination could occur in various pH (i.e.

Life cycle assessment of bio-based levoglucosan production from cotton straw through fast pyrolysis.

This study aimed to evaluate the environmental impacts (i.e. global warming potential (GWP) and resource depletion (RD)) of the bio-based levoglucosan production process through fast pyrolysis of cotton straw via life cycle assessment (LCA).

Anaerobic Soil Disinfestation Reduces Viability of and Sclerotia and Root-Knot Nematodes in Muck Soils.

Experiments were conducted to evaluate potential functional and mechanistic differences in the suppression of and and root-knot nematodes in muck soils by anaerobic soil disinfestation (ASD) using different carbon source amendments. Volatile compounds produced during ASD in muck soil amended with molasses, wheat bran, or mustard greens at 20.2 Mg/ha or a 2% ethanol solution significantly reduced the mycelial growth and number of sclerotia produced by both spp.

Effects of temperature and inoculation ratio on methane production and nutrient solubility of swine manure anaerobic digestion.

This study investigated the effects of temperature and volatile solids (VS) ratio of feedstock to inoculum (F/I ratio) on methane (CH) production and the solubility of nitrogen (N), phosphorus (P), cooper (Cu), and Zinc (Zn) after anaerobic digestion (AD) of swine manure. The highest cumulative CH yield of 470 L/kgVS was obtained with F/I ratios of 2.0 and 3.

Liquid hot water pretreatment to enhance the anaerobic digestion of wheat straw-effects of temperature and retention time.

Wheat straw is an abundant agricultural waste that is rich in lignocellulose. However, its waxy surface, highly crystallized structure, and limited surface area make it difficult to be hydrolyzed and used efficiently by microorganisms. Liquid hot water (LHW) pretreatment was studied to explore the feasibility of improving the methane yield of wheat straw in anaerobic digestion (AD).

Environmental Assessment of a Hybrid Solar-Biomass Energy Supplying System: A Case Study.

Local energy supply by renewable energy, such as solar energy and biomass, using distributed energy systems plays an important role in global energy structure. This study investigated the environmental performance of a hybrid solar-biomass energy supplying system by life-cycle assessment method. The results showed that in terms of environmental and energy impacts, the construction stage and the disassembly and recycling stage of the system contribute little to the whole life-cycle environmental impacts.