Remediation of soda-saline-alkali soil through soil amendments: Microbially mediated carbon and nitrogen cycles and remediation mechanisms.

Due to the high salt content and pH value, the structure of saline-sodic soil was deteriorated, resulting in decreased soil fertility and inhibited soil element cycling. This, in turn, caused significant negative impacts on crop growth, posing a major challenge to global agriculture and food security. Despite numerous studies aimed at reducing the loss of plant productivity in saline-sodic soils, the knowledge regarding shifts in soil microbial communities and carbon/nitrogen cycling during saline-sodic soil improvement remains incomplete. Consequently, we developed a composite soil amendment to explore its potential to alleviate salt stress and enhance soil quality. Our findings demonstrated that the application of this composite soil amendment effectively enhanced microbial salinity resistance, promotes soil carbon fixation and nitrogen cycling, thereby reducing HCO3- concentration and greenhouse gas emissions while improving physicochemical properties and enzyme activity in the soil. Additionally, the presence of CaSO4 contributed to a decrease in water-soluble Na+ content, resulting in reduced soil ESP and pH by 14.64 % and 7.42, respectively. Our research presents an innovative approach to rehabilitate saline-sodic soil and promote ecological restoration through the perspective of elements cycles.

Chemotaxis-mediated degradation of PAHs and heterocyclic PAHs under low-temperature stress by Pseudomonas fluorescens S01: Insights into the mechanisms of biodegradation and cold adaptation.

As wellknown persistent contaminants, polycyclic aromatic hydrocarbons (PAHs) and heterocyclic polyaromatic hydrocarbons (Heterocyclic PAHs)'s fates in cryogenic environments are remains uncertain. Herein, strain S01 was identified as Pseudomonas fluorescens, a novel bacterium tolerant to low temperature and capable of degrading PAHs and heterocyclic PAHs. Strain S01 exhibited growth at 5-40 â„ƒ and degradation rate of mixed PAHs and heterocyclic PAHs reached 52% under low-temperature. Through comprehensive metabolomic, genomic, and transcriptomic analyses, we reconstructed the biodegradation pathway for PAHs and heterocyclic PAHs in S01 while investigating its response to low temperature. Further experiments involving deletion and replacement of methyl-accepting chemotaxis protein (MCP) confirmed its crucial role in enabling strain S01's adaptation to dual stress of low temperature and pollutants. Additionally, our analysis revealed that MCP was upregulated under cold stress which enhanced strain S01's motility capabilities leading to increased biofilm formation. The establishment of biofilm promoted preservation of distinct cellular membrane stability, thereby enhancing energy metabolism. Consequently, this led to heightened efficiency in pollutant degradation and improved cold resistance capabilities. Our findings provide a comprehensive understanding of the environmental fate of both PAHs and heterocyclic PAHs under low-temperature conditions while also shedding light on cold adaptation mechanism employed by strain S01.

Energy utilization of agricultural waste: Machine learning prediction and pyrolysis transformation.

The rapid screening of agricultural waste materials for capacitor preparation holds significant importance in comprehending the relationship between material properties and enhancing experimental efficiency. In this study, we developed two machine learning models to predict electrode material characteristics using 2997 data points extracted from 235 articles. The identification and influence of key features on prediction indices provide a theoretical foundation for subsequent practical preparation. Through regression analysis and index evaluation, corn straw emerged as the optimal material for capacitor preparation, leading us to propose a one-step activation and two-step modification approach to convert corn straw into porous biochar. By modifying biochar with Co(NO3)2·6H2O, the maximum electrode capacitance of porous carbon reached 732.6 F/g. Furthermore, the electrode exhibited exceptional cycle stability with a remaining capacitance of 96 % after 5000 cycles. The prepared symmetric capacitor demonstrated pseudocapacitance behavior with a capacitance of 183.15 F/g at a current density of 1.0 A/g, power density of 22 kW/kg, and energy density of 9.03 Wh/kg. Considering the increasing annual output of corn straw and its superior industrial application prospects compared to acid-, base-, or precious metal-based alternatives due to their cost-effectiveness and environmental friendliness, these findings highlight the potential practical value in utilizing modified corn straw biochar as an efficient energy storage electrode material.

Factors Affecting Purchase Intention of Hanfu: Considering Product Identification, Cultural Motivation, and Perceived Authenticity.

With the trend of national cultural confidence and the growing appreciation for aesthetic diversity, traditional apparel from different countries or regions has become a driving force in the clothing industry. Hanfu, an emerging trend that industrializes traditional culture, has garnered increasing attention from consumers. Thus, with the objective of exploring the psychological antecedents of Hanfu consumers' purchase intentions from the perspectives of product identification, cultural motivation, and consumers' perceived authenticity, the present study was empirically conducted with a sample of 823 respondents. Partial least squares-structural equation modeling (PLS-SEM) was employed to examine the proposed research model. The results demonstrate that consumers' identification with Hanfu and cultural motivation positively influence object-based and existential authenticity, as well as purchase intention. Furthermore, the mediating effect of perceived object-based authenticity is confirmed, indicating its significance in shaping consumers' purchase intentions, while the mediating effect of existential authenticity is found to be insignificant. Research findings could contribute to the understanding of the psychological mechanisms driving consumers' purchase intentions towards traditional clothing and highlight the importance of consumers' perceived object-based authenticity in the market of traditional cultural clothing.

Insight into the soil aggregate-mediated restoration mechanism of degraded black soil via biochar addition: Emphasizing the driving role of core microbial communities and nutrient cycling.

Soil microbial communities are responsive to biochar application. However, few studies have investigated the synergistic effects of biochar application in the restoration of degraded black soil, especially soil aggregate-mediated microbial community changes that improve soil quality. From the perspective of soil aggregates, this study explored the potential microbial driving mechanism of biochar (derived from soybean straw) addition in black soil restoration in Northeast China. The results showed that biochar significantly improved the soil organic carbon, cation exchange capacity and water content, which play crucial roles in aggregate stability. The addition of biochar also significantly increased the concentration of the bacterial community in mega-aggregates (ME; 0.25-2 mm) compared with micro-aggregates (MI; <0.25 mm). Microbial co-occurrence networks analysis showed that biochar enhanced microbial interactions in terms of the number of links and modularity, particularly in ME. 16 S rRNA sequencing predicted that the expression of genes related to carbon (rbcL, acsA, gltS, aclB, and mcrA) and nitrogen (nifH and amoA) transformation increased after the addition of biochar. Furthermore, the functional microbes involved in carbon fixation (Firmicutes and Bacteroidetes) and nitrification (Proteobacteria) were significantly enriched and are the key regulators of carbon and nitrogen kinetics. Structural equation model (SEM) analysis further showed that the application of biochar promoted soil aggregates to positively regulate the abundance of soil nutrient conversion-related microorganisms, thereby increasing soil nutrient content and enzyme activities. These results provide new insights into the mechanisms of soil restoration through biochar addition.

The role of biochar in the photocatalytic treatment of a mixture of Cr(VI) and phenol pollutants: Biochar as a carrier for transferring and storing electrons.

Biochar (BC) is widely used to remove environmental pollutants due to its photocatalytic activity. However, the mechanism of BC in photocatalysis remains unclear. In this study, soybean straw biochar (D500), dewatered sludge biochar (S500) and TiO2/BC composite catalysts were prepared to test their photocatalytic activity in the photocatalysis-dark reaction using phenol and Cr(VI) as the representative pollutants. D500 had a good graphitized structure, layered structure and more active sites, which led to good photocatalytic activity. Compared with D500, S500 did not have a similar structure, resulting in a lack of photocatalytic activity. In addition, the efficiency of Cr(VI) and phenol removal using D500/TiO2 as a catalyst was higher than that obtained using D500 and TiO2, respectively. TiO2 coupled with D500 increased the generation of photoexcited electrons and reduced the recombination of e--h+ pairs. The removal efficiency of TiO2/D500 for Cr(VI) (80.4 %) and phenol (77.7 %) in the hybrid systems was higher than that of Cr(VI) and phenol in unitary systems. This difference was mainly attributed to the inhibition of e--h+ pair recombination by phenol and Cr(VI), which function as electron quenchers and hole quenchers, respectively. Furthermore, D500 stored electrons under light and released these electrons under dark conditions. When D500 was combined with TiO2, the electrons on the biochar activated the catalytic redox activity of TiO2, thereby removing pollutants under dark conditions. Meanwhile, TiO2/D500 also exhibited good reusability and stability. In summary, this study provides new insight into the role of biochar in photocatalysis.

Effect of biodegradable film mulching on crop yield, soil microbial and enzymatic activities, and optimal levels of irrigation and nitrogen fertilizer for the Zea mays crops in arid region.

Biodegradable film mulching (BM) is considered as the best alternative to plastic film mulching (PM) since it can prevent pollution caused due to plastic residues. However, the differences in soil microbial biomass and enzymatic activities between BM and PM, especially for different soil water and nitrogen contents remain ambiguous. In this study, the effects of BM, PM, and no film mulching (NM) on soil microbial biomass C (Cmic), N (Nmic), soil enzymes, and soil C/N ratio in a cornfield were evaluated using experimental data from 2018 and 2019. Additionally, different irrigation depths (30 mm, 22.5 mm, and 15 mm) and N-fertilizer application levels (280 kg ha-1 and 210 kg ha-1) were used in BM. The experimental results demonstrated no apparent differences between the Cmic, Nmic, and soil enzymes between BM and PM in the early stage (elongation stage), but these values under BM were significantly lower than that of PM in the middle stage of crop growth (tasseling and filling stages). Soil sucrase, catalase, and urease under PM were increased by 20.2%, 0.6%, and 12.0%, respectively, compared to BM. The analysis of Cmic, Nmic, soil enzymes, and crop yield under different irrigation and N-fertilizer application levels demonstrated the preponderance of BM22.5, 280, showing the highest yield of 14,110.1 kg ha-1 and NUE of 61.7.

A novel biodemulsifier of Bacillus mojavensis XH1 - Oxalate decarboxylase with the potential for demulsification of oilfield emulsion.

In recent years, special attention has been devoted to biodemulsifiers as a new type of environment-friendly demulsifiers. A novel biodemulsifying oxalate decarboxylase (OxdC) secreted by Bacillus mojavensis XH1 is reported in the present study. A genome-wide comparison showed that strains with high demulsification efficiencies all possess alkane degradation genes. An analysis of the differentially expressed genes and proteins induced by different substrates showed that OxdC secreted by XH1 was an effective demulsifier. Moreover, the demulsification ability was verified by prokaryotic gene expression, knockout and complementation analyses. OxdC from XH1 exhibited a strong demulsification capacity and significantly outperformed the model protein Bacillus subtilis 168 OxdC (Yvrk), which shared a high amino acid similarity but showed limited demulsification ability. Based on a comparison of the structural characteristics, the hydrophobic amino acids on the surface of OxdC were identified as a key factor driving the favorable demulsification activity of XH1. The metabolic pathways of XH1 used liquid paraffin and glucose as substrates, illustrating that hydrocarbons are necessary for biodemulsifier secretion. The present study provides new insight into the application of OxdC as an additional genetic resource in biodemulsification.

[Chemical Evolution and Formation Mechanism of Groundwater in Hetao Irrigation Area].

Groundwater resources are important sources of water in the arid region of northwestern China, but their overexploitation and utilization has led to a series of ecological and environmental problems. Exploring the characteristics and mechanism of groundwater chemical evolution is important for the rational use of groundwater resources. The characteristics of groundwater chemical evolution were studied in the Yongji Irrigation Area of Hetao Irrigation District and the formation mechanism of the chemical compounds in groundwater were investigated using cluster analysis, factor analysis, and other statistical methods. The influence degree of different factors was calculated. The results showed that the major cations in groundwater in the study area were Na+ and K+, and the major anions were Cl- and HCO3-. Moreover, Na+, K+, and Cl- showed high spatial variability and were the main factors contributing to groundwater salinization. The major chemical compounds in the groundwater in the study area were Cl-Na, HCO3 ·Cl ·SO4-Na, and HCO3-Na. Based on the cluster analysis results, the groundwater was divided into four categories (A1, A2, B1, and B2), of which A1 was highly mineralized by Cl-Na type water, while A2, B1, and B2 were mainly HCO3 ·Cl ·SO4-Na and HCO3-Na type water. Principal component analysis results suggest that groundwater chemistry was mainly affected by salinization, carbonate karstification, and human activities with the influence degrees of 45.976%, 23.853% and 16.678%, respectively. Evaporation, salt rock dissolution, and cation exchange were important sources of Na+ and Cl- accumulation in the irrigation area. Agricultural irrigation (leaching of soil salts) and drought (intense transpiration) were the key drivers of groundwater salinization in the irrigation area.

Mechanism of the biodemulsifier-enhanced biodegradation of phenanthrene by Achromobacter sp. LH-1.

Biodemulsifiers are widely applied in petroleum processing, mining and petroleum pollution treatment. Polycyclic aromatic hydrocarbons (PAHs) are a common component in petroleum-polluted environments; however, little is known about the mechanism behind the effect of biodemulsifiers on promoting PAH biodegradation. To obtain clear mechanistic insights, the facilitating effects of biodemulsifiers on the bioavailability of phenanthrene (PHE), which is used as a model PAH, and the cell membrane properties of PHE-degrading bacteria Achromobacter sp. LH-1 were researched. The results showed that LH-1 achieved a 96.1 % degradation rate and a 60 % adsorption rate. Biodemulsifiers could encapsulate PHE within micelles to solubilize PHE and increase the cell surface hydrophobicity (CSH) of LH-1 to improve the association of LH-1 with PHE. Furthermore, biodemulsifier molecules can be embedded in the phospholipid bilayer of the LH-1 membrane to increase the permeability and the area of the LH-1 membrane, and they can increase the unsaturated fatty acid contents of the LH-1 membrane to loosen the arrangement of carbon chains, thus further facilitating the uptake of PHE by LH-1 for biodegradation. These results suggest that biodemulsifiers are powerful biological products for increasing the degradation potential of PHE-degrading bacteria in ecosystems, and their application will be important for the economical and efficient bioremediation of PHE-contaminated environments.

Effects of residual plastic-film mulch on field corn growth and productivity.

Plastic-film mulching has played an important role to promote agricultural production in arid areas; however, due to its inefficient recycling capacity, large amounts of residues have been accumulated in soils, causing negative impacts on crop growth and on the environment. To investigate these effects on water use efficiency, a two-years field experiment was carried out, applying different levels of plastic-film residues, from 0 to 600 kg ha-1. Results show that these residues have a negative impact on root and shoot growth at several growth stages of corn crop, particularly if above 300 kg ha-1. Root length and weight density decrease with the amount of residues throughout the majority of crop season. Plastic-film residues of about 600 kg ha-1 are responsible for the decrease of the biomass root to shoot ratio during the tasseling stage. Moreover, during physiological maturity, root and shoot revealed the highest sensitivity, and the least negative effects on the root system. Results also show that crop water consumption has a slight decrease with the plastic-film residues, though there was also a significant decrease of the yield and the water use efficiency reduction. This information allows to state that it is determinant to learn how to deal with the problem, adjusting the irrigation and crop management to avoid yield impacts. It would also be important to find an efficient procedure to mechanically collect the residues in the soil, and to apply new biodegradable film mulching.

Evaluating soil nitrate dynamics in an intercropping dripped ecosystem using HYDRUS-2D.

The competition mechanisms between crop species for water and nutrients, especially nitrate (NO3-N), in intercropping ecosystems are still poorly understood. Therefore, an experiment involving high (300 kg ha-1 for corn and 250 kg ha-1 for tomato), medium (210 kg ha-1 for corn and 175 kg ha-1 for tomato), and low (150 kg ha-1 for corn and 125 kg ha-1 for tomato) N-fertilizer applications (HF, MF, LF, respectively) was conducted in the corn and tomato intercropping ecosystem during 2014 (a calibration period for modeling) and 2015 (a validation period for modeling). The modified HYDRUS-2D code was used to analyze soil NO3-N concentrations (SNC) in the middle between corn rows (Pc), between corn and tomato rows (Pb), and between tomato rows (Pt), NO3-N exchange in the horizontal direction between different regions, NO3-N leaching from the corn, the bare, and the tomato region, and N uptake by crops. Simulated SNCs were in good agreement with measurements, with RMSE, NSE, and MRE of 0.01-0.06 mg cm-3, 0.75-0.98, and 8.7-19.1%, respectively, during the validation period (2015). Average SNCs in the 0-40 cm soil layer were different between Pc, Pt, and Pb. Intensive NO3-N exchange in the horizontal direction occurred during the second stage (Day After Sowing [DAS] 37-113 in 2014; DAS 29-120 in 2015). NO3-N exchange between the corn and bare regions was lower than between the tomato and bare regions due to smaller concentration gradients. However, in the vertical direction, NO3-N leaching from the corn region in both years was 4.1 and 8.8 times larger, respectively, than from the tomato region under HF since NO3-N mainly moved from the tomato region to the corn region. Our results reveal the competition between corn and tomato for N and provide a rationale for formulating and optimizing different fertilizer regimes for different crops in the intercropping ecosystem.

[Effects of canal-lining project on groundwater and ecological environment in Hetao Irrigation District of Inner Mongolia].

The canal-lining project in Hetao Irrigation District (HID) for water-saving irrigation has been implemented for many years. By using statistical method, ordinary Kriging, and software ArcGIS 9.0, this paper analyzed the spatiotemporal variation of groundwater table depth and salinity in HID in September, 2001 and 2009. In the meantime, the vegetation distribution on the both shores of the lining part and non-lining part of Yangjiahe channel was also investigated. After the many years implementation of the project, the water diversion amount in HID in 2009 was reduced to 44.5 x 10(8) m3. The region area of groundwater table with a depth of 2.5-3.0 m was increased from 1.2 x 10(4) hm2 in 2001 to 9.11 x 10(4) hm2 in 2009. The region area of groundwater table with a depth of 2.0-2.5 m in 2009 took 80% of the total area of HID. In the northwestern region of HID, the groundwater salinity had reduced from 5000-10000 mg x L(-1) to 3000-5000 mg x L(-1). In Wulate irrigation region, the areas of salt water belt and half-salt water belt were increasing. After the canal-lining of Yangjiahe channel, the plant species and diversity index on both shores reduced, and some herbaceous plants with shallow roots showed degradation signs. The implementation of the project and the reduction of water diversion for irrigation did not exert negative effects on the maintenance of water surface area of Wuliangsuhai Lake.