The present study aimed to accelerate the humification and to investigate how MnO 2 modification of biochar (MBC) drives the humus formation during composting with chicken manure. In this study, compared with the control group (CK), the addition of MBC caused an increase in the concentration of both humus and humic acid (HA), with a respective enha...

The substantial release of NH 3 during composting leads to nitrogen (N) losses and poses environmental hazards. Additives can mitigate nitrogen loss by adsorbing NH 3 /NH 4 , adjusting pH, and enhancing nitrification, thereby improving compost quality. Herein, we assessed the effects of combining bacterial inoculants (BI) (1.5%) with tricalcium pho...

The Heilongjiang River Basin is a vast area with significant DOM sources and composition differences. The mechanism of DOM degradation under spatial variation remains unclear. This research investigated the degradation characteristics of DOM in different watersheds of the Heilongjiang River. DOM levels were higher in midstream waters, while DOM deg...

Chicken manure, as an organic solid waste with a high nitrogen content, generates large amounts of ammonia during composting, which leads to pollution of the surrounding environment, and causes a reduction in the quality of the compost product. Nitrogen is transformed through the nitrogen cycle and bacterial communities are the main contributors to...

The application of straw biochar to chicken manure composting mitigated nitrogen loss. However, the impact of biochar derived from different types of straw on nitrogen fixation in chicken manure composting is discrepant, and the specific pathways remain unclear. Therefore, this study aimed to clarify the specific pathways of maize straw biochar (M)...

Microbial shikimic acid is an important intermediate metabolite in the synthesis of aromatic amino acids which are precursors for forming humus during composting process. Generally, the pathways producing shikimic acid and its downstream products are collectively referred as shikimic acid pathway (SKP). Microbial SKP can produce phenols, and tyrosi...

This study aimed to explore the action mechanism of fungal community on the enhancement of humification during chicken manure composting by regulating the core pathway of carbon metabolism - the tricarboxylic acid cycle. Regulators adenosine triphosphate (ATP) and malonic acid were added at the beginning of composting. The analysis of changes in hu...

Background Understanding the functional diversity, composition, and dynamics of microbiome is critical for quality in composting. Denitrifying microbiota, possessing multiple metabolic pathways simultaneously. Denitrification-based biodegradation of aromatic metabolites has been widely applied in the bioremediation of sediments. However, role in bi...

Phosphorus in wastewater sludge is one of the important nutrients for biological growth and an important non-renewable resource. Most research in the composting field focuses on the C/N ratio, but there are few reports on initial carbon-phosphorus (C/P) ratio regulation. This study investigated the effects of different initial C/P ratios on phospha...

The aim of this study was to assess the effectiveness of biochar and montmorillonite islands on heavy metal adsorptive immobilization and identify crucial driving factors and pathways during chicken manure composting. Compared to montmorillonite (6.74 and 89.25 mg/kg), biochar exhibited an obviously higher ability of Cu and Zn enrichment (41.79 and...

The study aims to clarify the driving factors of lignocellulose degrading enzyme genes abundance during rice straw composting. Lignocellulose degrading strains b4 (Bacillus subtilis), z1 (Aspergillus fumigatus) were inoculated into pure culture, respectively. Meanwhile, three rice straw composting groups were set up, named CK (control), B4 (inocula...

The sulfate reduction reaction releases malodorous gases (H2S) during composting, with potential pollution risks to the environment. In this study, chicken manure (CM) with high sulfur content and beef cattle manure (BM) with low sulfur content were used to investigate the effect of control (CK) and low moisture content (LW) on sulfur metabolism. T...

This study aimed to explore the effect of Fenton-like reactions on lignocellulosic degradation performance and identify their driving factors during composting. Rice straw was pretreated by inoculating Aspergillus fumigatus Z1 and then adding Fe (II), which resulted in Fenton-like reactions. The treatment groups included CK (control), Fe (addition...

This study set out to explore the impact of lignite on preserving organic matter and promoting the formation of humic acid (HA) during chicken manure composting. Composting test was carried out for control (CK), 5 % lignite addition treatment (L1), 10 % addition treatment (L2) and 15 % addition treatment (L3). The results demonstrated that lignite...

Metal pollution caused by industrial waste accumulation is a long-term and far-reaching problem. Humin (HM), as a highly condensed organic component insoluble in alkaline or water solution, is often discarded as humic acid industrial waste. However, the abundant active functional groups in HM reported by some researches make it possible for HM to r...

Nitrogen losses through ammonia (NH3) emission were an unavoidable issue during chicken manure composting. Calcium superphosphate can be added to effectively limit the emission of NH3. The results show that adding calcium superphosphate in the heating, high temperature and cooling stages reduces ammonia emission by 18.48%, 28.19% and 0.91% respecti...

The addition of biochar could mitigate the bioavailability of heavy metals during livestock manure composting. However, the main action mechanism of biochar, such as how it worked, was ambiguous. Therefore, in this study, materials (biochar, alkali modified biochar, pretreated cotton ball) were added by embedding with nylon mesh bags to explore the...

Horizontal gene transfer of heavy metal resistance genes and antibiotic resistance genes in bacteria frequently occurred during composting. However, the relevancy between heavy metal pollution with different degrees and the occurrence of horizontal gene transfer during composting was unclear. Therefore, this study aimed to clarify the underlying re...

Dissolved organic matter (DOM) can strongly bind to organic contaminants and control phenanthrene in soil. Herein, four individual parallel factor analysis (PARAFAC) components were found in soil DOM. Component C1 was the humic-like component ligand T, and component C2 was a combination of humic fluorophore ligands M1 and M2. Furthermore, component...

Reactive composting is a promising technology for recovering valuable resources from food waste, while its manual regulation is laborious and time-consuming. In this study, machine learning (ML) technologies are adopted to enable automated composting by predicting compost maturity and providing process regulation. Four machine learning algorithms,...

As a kind of livestock manure, chicken manure (CM) was rich in organic matter and microorganisms. However, a large amount of foul gas discharged by its random stacking not only threatened the environment, but also caused harm to human health. In view of the serious carbon loss and the unclear action mechanism of microbial community on carbon metabo...

Microbes are the drivers for disposing of organic solid waste (OSW) during aerobic fermentation. Notwithstanding, the significance of microbes is underestimated in numerous studies on aerobic fermentation product assessments. Here, we investigated the humification degree (HD), and the humic acid content was assessed in terms of the bacterial commun...

Fulvic acid which could govern the environmental geochemistry behavior of heavy metals is considered as the eco-friendly substances for controlling heavy metal pollutants in environment. Knowledge on the individual fulvic acid ligand is crucial to characterize the effect of fulvic acid on the migration and toxicity of metal pollutants. Herein, fulv...

Dissolved organic matter (DOM) has important impacts on the transportation of antibiotics through chemical and biological processes in composting. The interaction between DOM and antibiotics is reciprocal. The interaction between DOM ligands and antibiotics could be characterized based on a technique combining parallel factor analysis (PARAFAC) and...

The main objective of this research was to investigate the effects of Phosphorus-Solubilizing Bacterial (PSB) inoculant on the bacterial structure and phosphorus transformation during kitchen waste composting. High throughput sequencing, topological roles, and multiple analysis methods were conducted to explain the links between phosphorus fraction...

In this present study, catechol was added to promote humus formation in chicken manure composting using 12.5-L working volume lab-scale reactors. Chicken manure composting were carried out on two treatments, control (CK) and 0.5% (w/w) catechol treated group. Results showed that catechol addition reduced organic matter loss and improved the content...

Metabolites of shikimic acid (SA) pathway can be used as humic substance (HS) precursors. Due to the complexity of SA anabolism, there were few studies on SA pathway during composting. The aim of this study was to identify the key drivers of SA pathway during different materials composting. During composting, the SA, protocatechuic acid (PA) and ga...

In this study, nitrogen transformation of chicken manure (CM) and cattle dung (CD) during composting was analyzed and its related functional keystones were identified. The results showed that chicken manure showed more severe nitrogen conversion during composting. The main N conversion factors in cattle dung were nitrite nitrogen (NO2–-N) and ammon...

Dissolved organic matter (DOM) can strongly complex with various contaminants. Therefore, DOM was deemed as an environmentally friendly substance for controlling the mobility, bioavailability, speciation, toxicity, and fate of metal contaminants in environment. In this study, composting-derived DOM was categorized into three fractions based on diff...

Black carbon (BC) exports huge amounts of its derived DOM from terrestrial ecosystems annually through a variety of ways (i.e., erosion or runoff migration). The pyrolytic feedstock type and temperature resulted in DOM derived from highly condensed aromatic and non-aromatic BC. However, the behaviors of low aromatic BC-derived DOM at diverse leachi...

This study aimed to explore the mechanism of actinomycetes inoculation to promote humification based on spectroscopy during straw waste composting. Results showed that inoculating actinomycetes could significantly increase the humification index and humification ratio, which were 2.53% and 21.79% respectively (P < 0.05). A spectroscopic analysis su...

This study aimed to clarify the conversion relationship between organic and inorganic nitrogen. The NH4Cl was used to enhance the inorganic nitrogen content. The key role of bacterial conversion of ammonium to organic nitrogen under ammonium stress was explored. Studies had shown that ammonium stress increased the amide nitrogen and bioavailable ni...

This study aimed to explore the main pathway of humic acid (HA) formation during the thermophilic phase (TP) of aerobic fermentation, clarify the contribution of aillard reaction. These experiments were carried out on cow dung, chicken manure and rice straw. Results indicated that the maximum temperature reached 60.2℃ during TP led to a sharp decre...

Promoting humus production by composting is meaningful for decreasing organic wastes pollution, and repairing contaminated environment. However, the interaction of multiple humus formation pathways has limited to understand how to improve humus formation by composting. Here, humus formation has been divided into biotic and abiotic pathways to quant...

The input of terrestrial materials is an essential source of dissolved organic matter (DOM) in rivers. The mechanism of the influence of terrestrial materials on the DOM cycle in the water column is still unclear. In this study, microbial degradation and photodegradation processes of DOM were evaluated after the input of terrestrial materials into...

Mink manure is one of the high nitrogenous wastes, which can easily cause nitrogen mineralization during composting, resulting in low resource reutilization. However, there are few studies on the resource utilization of mink manure. Therefore, this study investigated the effects of functional microbial (bacterial and actinomycetes agents) inoculati...

Dissolved organic matter (DOM) plays a vital role in the biogeochemistry of aquatic ecosystems. However, the mechanisms of DOM cycling in the water column during different seasons have not been fully elucidated to date. The differences in DOM degradation in summer, autumn, and winter water columns were evaluated in this study. The results showed th...

This study compared effects of clay minerals before and after firing in immobilization of organic nitrogen and reducing of nitrogen loss during chicken manure composting. The clay minerals and fired clay minerals treatments increased organic nitrogen contents and significantly reduced nitrogen loss, the loss was in order CK (52.61%) > M (47.15%) >...

The tricarboxylic acid cycle experienced will cause a lot of carbon and nitrogen (N) losses during aerobic composting, and the greenhouse gases produced will do great harm to ecological balance and human health. Thus, the purpose of this study was to investigate the role of metabolic regulators like adenosine triphosphate and malonic acid in the or...

To explore the eutrophication degree in the typical lakes and reservoirs of the northeast region of China, the bioavailability of dissolved organic phosphorus (DOP) of the lakes has been examined in this study. The laboratory incubation was carried out at 20 °C for 55 days and the concentrations of total dissolved phosphorus (TDP), dissolved reacti...

Heavy metal pollution was the main risk during livestock manures composting, in which microorganisms played a vital role. However, response strategies of microbial community to heavy metals stress (HMS) remained largely unclear. Therefore, the objective of this study was to reveal the ecological adaptation and counter-effect of bacterial community...

Transforming organic waste into stable carbon by composting is an eco-friendly way. However, the complex environment, huge microbial community and complicated metabolic of composting have limited the directional transformation of organic carbon, which is also not conducive to the fixation of organic carbon. Therefore, this review is based on the fo...

This study was aimed at exploring the mechanism of promoting humus formation by the addition of exogenous amino acids. Amino acids not only participated in the synthesis of humus directly as precursors, but also changed the functions of bacterial communities. The composition and diversity of bacterial community changed with the addition of amino ac...

The aims of this article were to study the effect of Fenton pretreatment and bacterial inoculation on cellulose-degrading genes and fungal communities during rice straw composting. The rice straw was pretreated by Fenton reactions and functional bacterial agents were then inoculated during the cooling phase of composting. Three treatment groups wer...

As an important part of lake ecosystems, sediments play a key role in the carbon cycle in lakes. Due to the complex sources of organic matter in sediments, the link between sequestration and transformation of humic substance is largely unknown. Therefore, it is essential to understand the characteristics of humic substance in lake sediments. In thi...

The aim of this study was to clarify the aromatic cleavage pathways and microbes involved in the adverse effect of nitrate on aromatic compounds humic substances during sludge composting. Results showed that the functional microbes involved in aromatic compounds humic substances precursors (catechol, tyrosine, tryptophan and phenylalanine) cleavage...

Denitrification during composting is a hidden danger that causes environmental pollution risk and aromatic humic substance damage, which needs to be better regulate urgently. In this study, two denitrification regulation methods, moisture and biochar amendment, were conducted during chicken manure composting. Denitrification performance data showed...

The final products of shikimic acid pathway, aromatic amino acids (AAA), can be used as humic acid (HA) precursors. Therefore, the aim of this study was to explore the contribution of shikimic acid pathway on the formation of HA during composting. Four composting treatments were carried out in this study, including the control, biochar addition, mo...

Here, we revealed the effects of microbes on fulvic acid (FA) formation in composting by adding MnO2. The results showed that the MnO2 promoted the formation of highly humified components (79.2% increased for component 2, and 45.8% increased for component 3) in FA. Additionally, core bacteria involved in FA transformation were identified, the MnO2...

Composting is a biodegradation and transformation process that converts lignocellulosic biomass into value-added products, such as humic substances. However, the recalcitrant nature of lignocellulose hinders the utilization of cellulose and hemicellulose, decreasing the bioconversion efficiency of lignocellulose. Pretreatment is an essential step t...

Improving the structure and quantity of humus is important to reduce agriculture organic waste by composting. The present study was aimed to assess the role of δ-MnO2 on humus fractions formation during co-composting of chicken manure and rice straw. Two tests (control group (CK), the addition of δ-MnO2 (M)) were carried out. The results showed tha...

The aims of this study were to identify the driving factors of humic acid (HA) during rice straw composting based on Fenton pretreatment with bacterial inoculation. Rice straw was pretreated by Fenton reactions and then inoculated during composting, which was set up CK (control), FeW (Fenton pretreatment) and FeWI (Fenton pretreatment+functional ba...

Bacillus is the classic inoculant in rice straw composting. However, there has been no in-depth study of the mechanism promoting the degradation of lignocellulose and the change of indigenous bacterial communities after Bacillus inoculation. Moreover, the stability of bacterial communities is a significant challenge in achieving the efficacy of ino...

Compost is a self-heating process for organic waste. Microbes are the main executors in composting process. However, due to low temperature in winter and low efficiency of composting, a lot of heat is lost in composting. In this study, taking-out and feed-batch composting method (TFC) can supplement nutrition and improve composting microenvironment...

This study investigated effects of high-nitrogen source (urea) (R_UR) and protein-like nitrogen source (chicken manure) (R_CM) on humification process during lignocellulose biomass composting. It demonstrated that decreasing ratio of crude fiber (CF), polysaccharide (PS) and amino acids (AAs) in R_CM (29.75%, 53.93% and 73.73%, respectively) was hi...

Background: Microbe is the driver for disposing of organic solid waste (OSW) during aerobic fermentation. Notwithstanding, the significance of microbe is always underestimated in numerous preceding studies about the aerobic fermentation products assessment. Results: Here, we investigate the humification degree (HD) and humic acid content could be a...

Microbes are the drivers for disposing of organic solid waste (OSW) during composting. Moreover, humus is a multipurpose biological macromolecule synthesized by microorganisms during composting. Here, we investigated the humification degree (HD), and the humus content was assessed in terms of the bacterial community. Microbial sequencing and bioinf...

The aim of this study was to identify critical driving factors and pathways of mitigating heavy metals (HM) bioavailability during biochar/montmorillonite-amended composting: emphasize on the interaction effect between organic constituents and functional bacteria. Organic components, such as humus (HS), humic (HA) and fulvic acid (FA) and dissolved...

Dissolved organic matter (DOM) derived from black carbon (BC) can migrate from soil to river by rainfall or snow melting in nature. Because of the incomplete biomass combustion, BC produced at various temperatures is mixed, which is hard to divide the DOM at single temperature. Then it is difficult to explore the properties and risks of DOM in deta...

During composting of chicken manure, the degradation of organic compounds is a key factor affecting the fate of chicken manure in the low temperature environment. Here, we studied the changes of main organic compounds, including carbohydrates, proteins and lipids and the role of key bacteria in composted at 10 °C. The degradation rates of total sug...

This study revealed core bacterial metabolic mechanisms involved in carbon (C) and nitrogen (N) in composting with adding MnO2. Two tests (control group (CK), adding MnO2 (M)) were performed. The results indicated that the MnO2 accelerated the transformation of carbon and nitrogen in composting. Core bacteria involved in the C and N conversion were...

Phosphate-solubilizing (PS) microbes are important to improve phosphorus availability and transformation of insoluble phosphate, e.g., rock phosphate (RP). The use of phosphate solubilizing bacteria (PSB) as inoculants have been proposed as an alternative to increase phosphate availability in RP and composting fertilizers. In this study, the effect...

The purpose of this study is to explore the action characteristics of metabolic regulators like adenosine tri-phosphate (ATP) and malonic acid (MA) during rice straw (RS) and fruit and vegetable waste (FVW) composting. Results showed that due to the easy degradation difference, ATP and MA reduced CO2 emission in RS and FVW, respectively. Moreover,...

The aim of this study was to evaluate nitrogen pollution risks from distinct materials composting with the discrepancy of component, including chicken manure, municipal solid and straw waste (CM, MSW, SW). Results showed total nitrogen maximum mean concentrations were observed in CM (39.57 g/kg). Pollution risks in CM were continuous, while MSW and...