Quantitative tracing the sources and human risk assessment of complex soil pollution in an industrial park.

Pollution in industrial parks has long been characterized by complex pollution sources and difficulties in identifying pollutant origins. This study focuses on a typical industrial park consisting of 11 factories (F1-F11) including organic pigment, inorganic pigment, and chemical factories in Hunan Province, China, here, a total of 327 sample points were surveyed. Eight pollutants (Mn, Cd, As, Co, NH3-N, l, 1,2-Trichloroethane, chlorobenzene, and petroleum hydrocarbons) were classified as contaminants of concern (COCs). This study assessed the contributions of driving factors to the distribution of COCs in the soil. Pollutant source apportionment was conducted using positive matrix factorization (PMF) and random forest (RF). The results revealed that the main factors driving pollution are groundwater migration, non-compliant emissions, leaks during production, and interactions among pollutants. The primary pollution sources were four chemical factories and an inorganic pigment factory. Source 5 demonstrates significant correlations with TCA (29.6%), CB (30%), and As (31.6%). Two chemical factories (F7 and F10) are the most significant pollution source with a risk assessment contribution rate of more than 60%. The present study sheds some light on the contamination characteristics, source apportionment and source-health risk assessment of COCs in industrial park. By utilizing the proposed research framework, decision-makers can effectively prioritize and address identified pollution sources.

Analysis of soil pollution characteristics and influencing factors based on ten electroplating enterprises.

The electroplating industry encompasses various processes and plating types that contribute to environmental pollution, which has led to growing public concern. To investigate related soil pollution in China, the study selected 10 sites with diverse industrial characteristics distributed across China and collected 1052 soil samples to determine the presence of industrial priority pollutants (PP) based on production process and pollutant toxicity. The factors influencing site pollution as well as proposed pollution prevention and control approaches were then evaluated. The results indicate the presence of significant pollution in the electroplating industry, with ten constituents surpassing the risk screening values (RSV). The identified PP consist of Cr(VI), zinc (Zn), nickel (Ni), total chromium (Cr), and petroleum hydrocarbons (C10-C40). PP contamination was primarily observed in production areas, liquid storage facilities, and solid zones. The vertical distribution of metal pollutants decreased with soil depth, whereas the reverse was true for petroleum hydrocarbons (C10-C40). Increase in site production time was strongly correlated with soil pollution, but strengthening anti-seepage measures in key areas can effectively reduce the soil exceedance standard ratio. This study serves as a foundation for conceptualizing site repair technology in the electroplating industry and offers a reference and methodology for pollution and source control in this and related sectors.

A strategy of co-fermentation of distillers dried grains with solubles (DDGS) and lignocellulosic feedstocks as swine feed.

To meet the sustainable development of the swine feed industry, it is essential to find alternative feed resources and develop new feed processing technologies. Distillers dried grains with solubles (DDGS) is a by-product from the ethanol industry consisting of adequate nutrients for swine and is an excellent choice for the swine farming industry. Here, a strategy of co-fermentation of DDGS and lignocellulosic feedstocks for production of swine feed was discussed. The potential of the DDGS and lignocellulosic feedstocks as feedstock for fermented pig feed and the complementary relationship between them were described. In order to facilitate the swine feed research in co-fermentation of DDGS and lignocellulosic feedstocks, the relevant studies on strain selection, fermentation conditions, targeted metabolism, product nutrition, as well as the growth and health of swine were collected and critically reviewed. This review proposed an approach for the production of easily digestible and highly nutritious swine feed via co-fermentation of DDGS and lignocellulosic feedstocks, which could provide a guide for cleaner swine farming, relieve stress on the increasing demand of high-value swine feed, and finally support the ever-increasing demand of the pork market.

Mechanism of Response of Watershed Water Quality to Agriculture Land-Use Changes in a Typical Fuel Ethanol Raw Material Planting Area-A Case Study on Guangxi Province, China.

Speeding up the promotion and application of biofuel ethanol has been a national strategy in China, which in turn has affected changes in the raw material planting structure. This study analyzed the response mechanism of water quality to agriculture land-use changes in a cassava fuel ethanol raw material planting area. The results revealed that an increase in cultivated land and construction land would lead to a rise in the load of TN (total nitrogen) and TP (total phosphorus), while an expansion in forest land and grassland area would reduce the load. As for crop structures, corn would have a remarkable positive impact on TN and TP, while rice and cassava performed in an opposite manner. Furthermore, scenarios under the carbon neutralization policy were carried out to forecast the nonpoint source pollutants based on the quantitative relations coefficients. It was proven that cassava planting was suitable for vigorous fuel ethanol development, but the maximum increase area of cassava should be 126 km2 to ensure economic benefits. Under the change in fuel ethanol policy, this study could provide scientific support for local agriculture land-use management in realizing the carbon neutralization vision and also set a good example for the development of the cassava fuel ethanol industry in other cassava-planting countries.

Synchronous electrochemical detection of dopamine and uric acid by a PMo12@MIL-100(Fe)@PVP nanocomposite.

In this work, a noble-metal-free composite electrode was prepared based on PMo12O403- (PMo12), C9H5FeO7 (MIL-100(Fe), a Fe-based metal organic framework) and polyvinylpyrrolidone (PVP), and served as a high performance electrochemical sensor for synchronous detection of dopamine (DA) and uric acid (UA). The PMo12@MIL-100(Fe)@PVP composite electrode was fabricated by a in-situ hydrothermal method. Thanks to the synergistic effect of three active components (PMo12, MIL-100 and PVP), the electrode possesses large specific surface area and high electrical conductivity and therefore it shows high electrocatalytic oxidation performance of DA and UA with a spacing of 0.146 V between the two peak positions. These benefits of the electrode enable its electrochemical sensor to synchronously detect of DA and UA. Namely, the linear ranges can achieve 1-247 µM for DA and 5-406 µM for UA. Meanwhile, the detection limits are 0.586 µM for DA and 0.372 µM for UA. Moreover, the sensor can be applied to simultaneous determination of UA and DA in human serums with satisfactory recovery values.

Digital soil mapping of soil total nitrogen based on Landsat 8, Sentinel 2, and WorldView-2 images in smallholder farms in Yellow River Basin, China.

Predicting spatial explicit information of soil nutrients is critical for sustainable soil management and food security under climate change and human disturbance in agricultural land. Digital soil mapping (DSM) techniques can utilize soil-landscape information from remote sensing data to predict the spatial pattern of soil nutrients, and it is important to explore the effects of remote sensing data types on DSM. This research utilized Landsat 8 (LT), Sentinel 2 (ST), and WorldView-2 (WV) remote sensing data and employed partial least squares regression (PLSR), random forest (RF), and support vector machine (SVM) algorithms to characterize the spatial pattern of soil total nitrogen (TN) in smallholder farm settings in Yellow River Basin, China. The overall relationships between TN and spectral indices from LT and ST were stronger than those from WV. Multiple red edge band-based spectral indices from ST and WV were relevant variables for TN, while there were no red band-based spectral indices from ST and WV identified as relevant variables for TN. Soil moisture and vegetation were major driving forces of soil TN spatial distribution in this area. The research also concluded that farmlands of crop rotation had relatively higher TN concentration compared with farmlands of monoculture. The soil prediction models based on WV achieved relatively lower model performance compared with those based on ST and LT. The effects of remote sensing data spectral resolution and spectral range on enhancing soil prediction model performance are higher than the effects of remote sensing data spatial resolution. Soil prediction models based on ST can provide location-specific soil maps, achieve fair model performance, and have low cost. This research suggests DSM research utilizing ST has relatively high prediction accuracy, and can produce soil maps that are fit for the spatial explicit soil management for smallholder farms.

Source apportionment and ecological and health risk mapping of soil heavy metals based on PMF, SOM, and GIS methods in Hulan River Watershed, Northeastern China.

Heavy metals in agricultural soils not only affect the food security and soil security, but also endanger the human health through the food chain. Based on the incorporation of index analysis, positive matrix factorization (PMF), self-organizing map (SOM), and geostatistical methods, this research performed the assessment of source apportionment and ecological and health risks of soil heavy metals in Hulan River Watershed, Northeastern China. According to the Pollution Load Index (PLI), 83.08% of the soil samples were slightly or mildly polluted, and 1.54% of the soil samples were severely polluted. The ecological risk index (EI) showed that about 80.77% and 60.77% of the soil samples were beyond the low risk level for Hg and Cd, respectively. In this research, the non-carcinogenic and carcinogenic risk indices for children were higher than adult males and adult females. Four potential sources were revealed based on the PMF and SOM analysis including atmospheric deposition and industrial emission; transportation source; agricultural source; and a combination of agricultural, industrial, and natural sources. Considerable and high ecological risk from Hg existed in the area close to the coal steam-electric plant, and considerable and high ecological risk from Cd existed in the Hulan River estuary area. The eastern part of the study area experienced higher non-carcinogenic and carcinogenic risks for adults and children than the western part of the study area. The source apportionment and ecological and health risk mapping provide important role in reducing pollution sources. Zonal pollution control and soil restoration measures should be performed in the areas with high ecological and health risks.

Distribution Characteristics and Risk Assessment of Agricultural Land Use Non-Point Source Pollution in Typical Biofuel Ethanol Planting Areas.

Speeding up the promotion and application of bio-fuel ethanol was a national strategy in China, which in turn affected changes in the raw material planting structure. This study analyzed the distribution of nitrogen and phosphorus forms in water bodies and the soil of the typical maize and cassava fuel ethanol raw material planting areas. The results revealed that the maize planting area faced more serious TN and TP pollution. The river pollution was greatly affected by TN, TP, Ex-P and Fe/Al-P in soil, while soil TN and NO3--N were the main factors influencing its counterpart. Furthermore, the risk assessment of soil nitrogen and phosphorus loss was carried out based on planting structures of crops. We investigated whether the water quality indexes or soil nitrogen and phosphorus loss risk assessment results showed that the Yujiang River stayed significantly less polluted. It was proven that the cassava planting area was more suitable for vigorously developing fuel ethanol. As for the high-risk areas, ecological agriculture promoting and fertilizer controlling measures were suggested. Under the change of the fuel-ethanol policy, this study could provide scientific support for the assessment of the impact of the Chinese national fuel ethanol policy on the water environment of the raw material planting area.

A comparative study on phosphate removal from water using Phragmites australis biochars loaded with different metal oxides.

Metal oxide-loaded biochars are a promising material to remove phosphate from polluted water to ultra-low concentrations. To facilitate preparing the metal oxide-loaded biochar with the best phosphate adsorption performance, five biochars loaded with Al, Ca, Fe, La and Mg oxides, respectively (Al-BC, Ca-BC, Fe-BC, La-BC and Mg-BC) were produced using Phragmites australis pretreated with 0.1 mol AlCl3, CaCl2, FeCl3, LaCl3 and MgCl2, respectively, characterized, and phosphate adsorption kinetics and isotherms of the biochars were determined. The maximum phosphate adsorption capacities (Qm ) of the biochars ranked as Al-BC (219.87 mg g-1) > Mg-BC (112.45 mg g-1) > Ca-BC (81.46 mg g-1) > Fe-BC (46.61 mg g-1) > La-BC (38.93 mg g-1). The time to reach the adsorption equilibrium ranked as La-BC (1 h) < Ca-BC (12 h) < Mg-BC (24 h) = Fe-BC (24 h)

[Effect of Biomass Particle Size on the Adsorption of Phosphorus from Aqueous Solution by MgO-loaded Biochar].

To study the effect of biomass particle size on the rate and ability of phosphorus removal from aqueous solution by MgO-loaded Phragmites australis biochar (MBC), MBC was prepared using 0.0-0.5, 1.0-2.0, and 6.0-8.0 mm Phragmites australis particles as the feedstock and MgCl2 as the modification material. The MBC was characterized using FTIR, XRD, and SEM techniques. Kinetic and isotherm experiments of phosphate (PO43--P) adsorption from aqueous solution by the MBC were conducted, and the experimental data were fitted with various kinetic and isotherm models. The results showed that the adsorption rate of PO43--P by the MBC increased with the increase in biomass particle size. The amount of PO43--P adsorbed by the MBC prepared from 0.0-0.5, 1.0-2.0, and 6.0-8.0 mm particles reached 15.4%, 25.8%, and 80.8%, respectively, within 2 h. The biomass particle size did not affect the maximum PO43--P adsorption capacity (249.0-254.7 mg·g-1) of the MBC. MBC prepared from the 6-8 mm particles retained the complete cell wall structure of the Phragmites australis, and a large number of micropores and mesopores were generated during pyrolysis, thereby forming a hierarchical, regular, and well-connected pore structure. MBC prepared from the 0.0-0.5 mm and 1.0-2.0 mm particles had inferior pore structures with inferior pore connectivity, which affected the diffusion rate of PO43- ions inside the MBC and limited the PO43--P adsorption rate. Therefore, when using waste Phragmites australis harvested from a constructed wetland to produce MBC and remove phosphorus from water, the Phragmites australis should be crushed into 6-8 mm particles. Over-crushing deteriorates the pore structure of the produced MBC and reduces the removal rate of phosphorus by the MBC.

Mn(OAc)3-Mediated Addition Reactions of NaSO2CF3 and Perhalogenated Carboxylic Acids with Unactivated Alkenes Conjectured by a Single Electron Transfer and Halogen Abstraction Mechanism.

A free-radical halotrifluoromethylation of olefins by using Mn(OAc)3·2H2O, CF3SO2Na, and perhalogenated carboxylic acids has been achieved. Perhalogenated carboxylic acids act as a halogen source and CF3SO2Na acts as a CF3 source. The reaction displayed good tolerance of functional groups in the substrates under mild conditions. The radical clock experiment and TEMPO inhibition experiment support a radical process. The halogen reagent competition experiment shows that the last step of halogenation process is mainly through a halogen abstraction mechanism.

High-Density pH-Auxostat Fed-Batch Culture of Schizochytrium limacinum SR21 with Acetic Acid as a Carbon Source.

Schizochytrium limacinum SR21 is an important strain for industrial production of docosahexaenoic acid (DHA), which is an important omega-3 fatty acid used in the nutraceutical and food industry. However, the high cost of carbon sources has limited its further application in the market with much larger volume, such as animal feed for aquaculture, poultry, and livestock. To seek low-cost carbon source, acetic acid is tested in the present study. The effect of different factors, including initial carbon source concentration, pH, aeration rate, and nitrogen sources, on biomass, lipid, and DHA production were tested. With optimized culture conditions, the biomass concentration of 146 g/L, total fatty acids (TFAs) of 82.3 g/L, and DHA content of 23.0 g/L were achieved with a pH-auxostat fed-batch cultivation. These results suggested that acetic acid is a promising feedstock for the low-cost production of DHA. Graphical Abstract.

N-doping effectively enhances the adsorption capacity of biochar for heavy metal ions from aqueous solution.

N-doping was successfully employed to improve the adsorption capacity of biochar (BC) for Cu2+ and Cd2+ by direct annealing of crop straws in NH3. The surface N content of BC increased more than 20 times by N-doping; meanwhile the content of oxidized-N was gradually diminished but graphitic-N was formed and increased with increasing annealing temperature and duration time. After N-doping, a high graphitic-N percentage (46.4%) and SBET (418.7 m2/g) can be achieved for BC. As a result, the N-doped BC exhibited an excellent adsorption capacity for Cu2+ (1.63 mmol g-1) and Cd2+ (1.76 mmol g-1), which was up to 4.0 times higher than that of the original BC. Furthermore, the adsorption performance of the N-doped BC remained stable even at acidic conditions. A positive correlation can be found between adsorption capacity with the graphitic N content on BC surface. The surface chemistry of N-doped BC before and after the heavy metal ions adsorption was carefully examined by XPS and FTIR techniques, which indicated that the adsorption mechanisms mainly included cation-π bonding and complexation with graphitic-N and hydroxyl groups of carbon surfaces.

An improved multi-objective optimization model for supporting reservoir operation of China's South-to-North Water Diversion Project.

An improved multi-objective optimization model based on goal programming (GP) for supporting reservoir operation was developed under inflow senarios of multiple runoff guarantee rates (i.e., 25%, 75%, perennial mean, and 95%) and ecological goals with the combination of steady- and pulse-state ecological water demands. Under these four scenarios, discharge flows of Danjingkou Reservoir would be 358.40, 369.67, 268.91 and 98.14×108m3/a, and those at Taocha Canal headwork would be 104.61, 86.62, 95.08 and 64.00×108m3/a, respectively. The generated results for stream flows could successfully meet the predetermined operational goals for the project. Comparatively, under the scenario of 95% runoff guarantee rate, the obtained strategies could not satisfy the ecological water demands. The modeling results indicated that the capacity of water diversion and storage for Danjiangkou Reservoir would be enhanced due to the operation of the South-to-North Water Diversion Project. The results showed the risks associated with possible flooding would be comparatively low under those four runoff guarantee rates. This represents the current priority for flood control in Danjiangkou Reservoir needs to be changed into multiple ones including ecological water supply, water transfer, as well as downstream water security maintenance.

One-step synthesis of a novel N-doped microporous biochar derived from crop straws with high dye adsorption capacity.

N-doping is one of the most promising strategies to improve the adsorption capacity and selectivity of carbon adsorbents. Herein, synthesis, characterization and dye adsorption of a novel N-doped microporous biochar derived from direct annealing of crop straws under NH3 is presented. The resultant products exhibit high microporosity (71.5%), atomic percentage of nitrogen (8.81%), and adsorption capacity to dyes, which is about 15-20 times higher than that of original biochar. Specifically, for the sample NBC800-3 pyrolyzed at 800°C in NH3 for 3 h, its adsorption for acid orange 7 (AO7, anionic) and methyl blue (MB, cationic) is up to 292 mg g(-1) and 436 mg g(-1), respectively, which is among the highest ever reported for carbonaceous adsorbents. The influences of N-doping and porous structure on dye adsorption of the synthesized carbons are also discussed, where electrostatic attraction, π-π electron donor-accepter interaction, and Lewis acid-base interaction mainly contribute to AO7 adsorption, and surface area (especially pore-filling) dominates MB adsorption. The N-doped biochar can be effectively regenerated and reused through direct combustion and desorption approaches.

An improved method for evaluating ecological suitability of hydropower development by considering water footprint and transportation connectivity in Tibet, China.

Ecological suitability evaluation for hydropower development is effective in locating the most suitable area for construction and emphasizes a clear direction for water resources governance. In this paper, water footprints and transportation connectivity were introduced to improve the existing ecological suitability evaluation application for hydropower development by revising the defects of the traditional indicator system. The following conclusions were reached. (1) Tibet was in a state of water use surplus; the prospect of further hydropower development is positive. (2) Chamdo, Lhasa and Nyingchi excelled in water use efficiency, and Ali was placed last. Nakchu was slightly superior to Ali, but it lagged behind the southern regions. Lhasa, Chamdo, Nyingchi, Xigaze and Shannan were suitable for hydropower development, which could further meet local needs and benefit other regions of China. (3) The evaluation results were in accordance with the actual eco-environmental conditions of the built hydropower projects, indicating that current hydropower development planning was basically reasonable.