A field investigation was performed to study the content, speciation and mobility of vanadium, as well as microbial response in soil from a stone coal smelting district in Hunan province of China. The results showed t...A field investigation was performed to study the content, speciation and mobility of vanadium, as well as microbial response in soil from a stone coal smelting district in Hunan province of China. The results showed that the contents of soil V ranged from 168 to 1538 mg/kg, which exceeded the maximum permissible value of Canadian soil quality for V. The mean soil V content from wasteland area reached 1421 mg/kg, and those from the areas related with slag heap, ore pile and smelting center were 380, 260 and 225 mg/kg, respectively. Based on the results of the modified BCR sequential extraction procedure, V contents in the mobile fractions varied from 19.2 to 637 mg/kg accounting for 7.4%-42.3% of total V, and those of V(+5) species were between 21.9 and 534.0 mg/kg. Soil enzyme activity and microbial basal respiration were adversely affected by high level of soil V. More attention should be paid to soil V pollution and potential hazardous surrounding the stone coal smelting district.展开更多
In situ coal gasification poses a potential environmental risk to groundwater pollution although it depends mainly on local hydrogeological conditions. In our investigation,the possible processes of groundwater pollut...In situ coal gasification poses a potential environmental risk to groundwater pollution although it depends mainly on local hydrogeological conditions. In our investigation,the possible processes of groundwater pollution origi-nating from underground coal gasification (UCG) were analyzed. Typical pollutants were identified and pollution con-trol measures are proposed. Groundwater pollution is caused by the diffusion and penetration of contaminants generated by underground gasification processes towards surrounding strata and the possible leaching of underground residue by natural groundwater flow after gasification. Typical organic pollutants include phenols,benzene,minor components such as PAHs and heterocyclics. Inorganic pollutants involve cations and anions. The natural groundwater flow after gasification through the seam is attributable to the migration of contaminants,which can be predicted by mathematical modeling. The extent and concentration of the groundwater pollution plume depend primarily on groundwater flow ve-locity,the degree of dispersion and the adsorption and reactions of the various contaminants. The adsorption function of coal and surrounding strata make a big contribution to the decrease of the contaminants over time and with the distance from the burn cavity. Possible pollution control measures regarding UCG include identifying a permanently,unsuitable zone,setting a hydraulic barrier and pumping contaminated water out for surface disposal. Mitigation measures during gasification processes and groundwater remediation after gasification are also proposed.展开更多
To feed an increasing population, large amounts of chemical nitrogen fertilizer have been used to produce much of our food, feed and fiber thereby increasing nitrogen levels in soils, natural waters, crop residues, li...To feed an increasing population, large amounts of chemical nitrogen fertilizer have been used to produce much of our food, feed and fiber thereby increasing nitrogen levels in soils, natural waters, crop residues, livestock wastes,and municipal and agricultural wastes, with national and international concern about its potential adverse effects on environmental quality and public health. To understand these phenomena and problems, first the nitrogen cycle and the environment are described. Then recent trends for nitrogen cycling through the food and feed system, N2O emissions from fertilized upland and paddy soils, and NO-3 pollution in ground water in Japan are reported. Finally, mitigation strategies in Japan for reducing N2O emission and NO-3 pollution are proposed, including nitrification inhibitors, controlled release fertilizers, utilization of plant species that could suppress nitrification, utilizing the toposequence, government policy, and appropriate agricultural practices. Of all the technologies presented, use of nitrification inhibitors and controlled release fertilizers are deemed the most important with further development of these aspects of technologies being expected. These practices, if employed worldwide, could help reduce the load, or environmental deterioration, on the Earth's biosphere.展开更多
Thick and ultra-thick coal seams are main coal seams for high production rate and high efficiency in Chinese coal mines, which accounts for 44 % of the total minable coal reserve. A fully mechanized top-coal caving mi...Thick and ultra-thick coal seams are main coal seams for high production rate and high efficiency in Chinese coal mines, which accounts for 44 % of the total minable coal reserve. A fully mechanized top-coal caving mining method is a main underground coal extraction method for ultra-thick coal seams. The coal extraction technologies for coal seams less than 14 m thick were extensively used in China. However, for coal seams with thickness greater than 14 m, there have been no reported cases in the world for underground mechanical extraction with safe performance, high efficiency and high coal recovery ratio. To deal with this case, China Coal Technology & Engineering Group, Datong Coal Mine Group, and other 15 organizations in China launched a fundamental and big project to develop coal mining technologies and equipment for coal seams with thicknesses greater than 14 m. After the completion of the project, a coal extraction method was developed for top-coal caving with a large mining height, as well as a ground control theory for ultra-thick coal seams. In addition, the mining technology for top-coal caving with a large mining height, the ground support technology for roadway in coal seams with a large cross-section, and the prevention and control technology for gas and fire hazards were developed and applied. Furthermore, a hydraulic support with a mining height of 5.2 m, a shearer with high reliability, and auxiliary equipment were developed and manufactured. Practical implication on the technologies and equipment developed was successfully completed at the No. 8105 coal face in the Tashan coal mine, Datong, China. The major achievements of the project are summarized as follows: 1. A top-coal caving method for ultra-thick coal seams is proposed with a cutting height of 5 m and a top-coal caving height of 15 m. A structural mechanical model of overlying strata called cantilever beam-articulated rock beam is established. Based on the model, the load resistance of the hydraulic support with a large mining height for top-coal caving method is determined. With the analysis, the movement characteristics of the top coal and above strata are evaluated during top-coal caving operation at the coal face with a large mining height. Furthermore, there is successful development of comprehensive technologies for preventing and controlling spalling of the coal wall, and the top-coal caving technology with high efficiency and high recovery at the top-coal caving face with a large mining height. This means that the technologies developed have overcome the difficulties in strata control, top-coal caving with high efficiency and high coal recovery, and enabled to achieve a production rate of more than 10 Mtpa at a single top-coal caving face with a large mining height in ultra-thick coal seams; 2. A hydraulic support with 5.2 m supporting height and anti-rockburst capacity, a shearer with high reliability, a scraper conveyor with a large power at the back of face, and a large load and long distance headgate belt conveyor have been successfully developed for a top-coal caving face with large mining height. The study has developed the key technologies for improving the reliability of equipment at the coal face and has overcome the challenges in equipping the top-coal caving face with a large mining height in ultra-thick coal seams; 3. The deformation characteristics of a large cross-section roadway in ultra-thick coal seams are discovered. Based on the findings above, a series of bolt materials with a high yielding strength of 500-830 MPa and a high extension ratio, and cable bolt material with a 1 × 19 structure, large tonnage and high extension ratio are developed. In addition, in order to achieve a safe roadway and a fast face advance, installation equipment for high pre-tension bolt is developed to solve the problems with the support of roadway in coal seams for top-coal caving operation with a large mining height; 4. The characteristics of gas distribution and uneven emission at top-coal caving face with large mining height in ultra-thick coal seams are evaluated. With the application of the technologies of gas drainage in the roof, the difficulties in gas control for high intensive top-coal caving mining operations, known as "low gas content, high gas emission", are solved. In addition, large flow-rate underground mobile equipment for making nitrogen are developed to solve the problems with fire prevention and safe mining at a top-coal caving face with large mining height and production rate of more than 10 Mtpa. A case study to apply the developed technologies has been conducted at the No. 8105 face, the Tashan coal mine in Datong, China. The case study demonstrates that the three units of equipment, i.e., the support, shearer and scraper conveyor, are rationally equipped. Average equipment usage at the coal face is 92.1%. The coal recovery ratio at the coal face is up to 88.9 %. In 2011, the coal production at the No. 8105 face reached 10.849 Mtpa, exceeding the target of 10 Mtpa for a topcoal caving operation with large mining height performed by Chinese-made mining equipment. The technologies and equipment developed provide a way for extracting ultra-thick coal seams. Currently, the technologies and equipment are used in 13 mining areas in China including Datong, Pingshuo, Shendong and Xinjiang. With the exploitation of coal resources in Western China, there is great potential for the application of the technologies and equipment developed.展开更多
Epidemiological studies have suggested that inhalation exposure to indoor ambient air from coal-burning environments is causally associated with respiratory health risks.In order to explore the toxicological mechanism...Epidemiological studies have suggested that inhalation exposure to indoor ambient air from coal-burning environments is causally associated with respiratory health risks.In order to explore the toxicological mechanisms behind the adverse health effects,the hemolytic activity of PM_(10)(particulate matter with an aerodynamic diameter of 10 um or less)samples collected from homes burning coal in the recognized China"cancer village"Xuanwei were evaluated and matched against their trace elemental contents.The results demonstrated that the hemolytic activity of indoor PM_(10) in coal-burning environments ranged from 4.28%to 5.24%,with a clear positive dose-response relationship.Although low dose samples exhibited a reduced hemolytic activity,PM_(10) could have a toxic effect upon people in a coal-burning indoor environment for extended time periods.The concentrations of analyzed trace elements in PM_(10) samples ranged from 6966 to 12,958 ppm.Among the analyzed elements,Zn,Ti,Ni,Cu,Pb,Ba,Mn,Cr and V were found at higher concentrations and accounted for over 95%of the total elements.The concentrations of total analyzed elements in the PM_(10) samples revealed a significant positive correlation with PM_(10) hemolytic activity.Of the analyzed elements,Zn,Pb and Cs positively correlated with hemolysis,while Li,U and V negatively correlated with the hemolysis of human red blood cells(RBCs).Therefore,the heavy metal elements could be one of the main factors responsible for the hemolytic capacity of indoor PM_(10) in coal-burning environments.展开更多
Batch experiments tively evaluate the inhibition were conducted to compara- effects and mechanisms of a low-concentration (1%) proline solution cover on the release of pollutants from high-sulfur coal gangue. High- ...Batch experiments tively evaluate the inhibition were conducted to compara- effects and mechanisms of a low-concentration (1%) proline solution cover on the release of pollutants from high-sulfur coal gangue. High- sulfur coal gangue was continuously immersed in a proline solution and in deionized water (as a control treatment) for 540 days. The results showed that the coal gangue in the control treatment was oxidized and generated leachate with poor water qualities, i.e., the leachate exhibited lower pH values, higher redox potential values, higher pollutant concentrations (804^2-, Fe, Mn, Cu, and Zn), and high levels of acidophilic sulfur-oxidizing bacteria. However, compared to the control treatment, the addition of the proline solution (1%) significantly improved the water quality of the leachate by significantly reducing the Eh values, the pollutant concentrations (804^2-, Fe^2+, Fe, Mn, Cu, and Zn), and the activity of acidophilic sulfur-oxidiz- ing bacteria and by significantly increasing the pH value to neutral. The proline treatment significantly inhibited the oxidation of coal gangue and the release of pollutants, mainly by inhibiting the activity of acidophilic sulfur-ox- idizing bacteria and by altering the heavy metal fractions and the mineralogical characteristics. Therefore, in engi- neering practice, workers should consider using an envi- ronmental friendly aqueous proline solution cover to achieve the in-situ control of pollutant releases from coal gangue dumps.展开更多
Over half of the world's population is exposed to household air pollution from the burning of solid fuels at home. Household air pollution from solid fuel use is a leading risk factor for global disease and remain...Over half of the world's population is exposed to household air pollution from the burning of solid fuels at home. Household air pollution from solid fuel use is a leading risk factor for global disease and remains a major public health problem, especially in low- and mid-income countries. This is a particularly serious problem in China, where many people in rural areas still use coal for household heating and cooking. This review focuses on several decades of research carried out in Xuanwei County, Yunnan Province, where household coal use is a major source of household air pollution and where studies have linked household air pollution exposure to high rates of lung cancer. We conducted a series of case-control and cohort studies in Xuanwei to characterize the lung cancer risk in this population and the factors associated with it. We found lung cancer risk to vary substantially between different coal types, with a higher risk associated with smoky(i.e., bituminous) coal use compared to smokeless(i.e., anthracite) coal use. The installation of a chimney in homes resulted in a substantial reduction in lung cancer incidence and mortality. Overall, our research underscores the need among existing coal users to improve ventilation, use the least toxic fuel, and eventually move toward the use of cleaner fuels, such as gas and electricity.展开更多
In this paper,a novel compound was developed by mixing H_(3)PO_(4)-modified cauliflower leaves hydrochar(CLH)and coal gangue-based Na-X zeolite(ZL).An alkaline soil contaminated with cadmium(Cd)and lead(Pb)was amended...In this paper,a novel compound was developed by mixing H_(3)PO_(4)-modified cauliflower leaves hydrochar(CLH)and coal gangue-based Na-X zeolite(ZL).An alkaline soil contaminated with cadmium(Cd)and lead(Pb)was amended through the individual and synergistic application of CLH and ZL(1%CLH,2%CLH,1%ZL,2%ZL and 1%CLH+1%ZL),and Chinese cabbage was grown on it.Individual application of CLH was superior to ZL on decreasing the pH of alkaline soil and increasing soil available phosphorus(Olsen-P)and soil organic matter(SOM).In contrast,their combined application significantly improved the soil cation exchange capacity(CEC).Besides,the 1%CLH+1%ZL was the most efficient treatment in decreasing diethylenetriamine pentaacetate(DTPA)-extractable Cd/Pb and concentrations of these two metals in cabbage root and shoot.Their synergistic application could better increase Cd and Pb immobilization and cabbage yield than their alone application.Furthermore,the immobilization of Pb for all treatments was higher than that of Cd.The synergistic immobilization mechanism of CLH and ZL reflected that the CLH precipitated and complexed with these two metals,which may block the pores of hydrochar or wrap on the surface of hydrochar.So the continuous adsorption and complexation were prevented.Nevertheless,ZL could probably alleviate this obstacle.This finding provides helpful information about using CLH combined with ZL as a soil stabilizer to immobilize heavy metals in contaminated alkaline soil.展开更多
In the process of using high-pressure flat membranes to treat coal chemical wastewater,the effects of high-pressure flat membranes on the concentration of salt ions and the removal of pollutants were studied under the...In the process of using high-pressure flat membranes to treat coal chemical wastewater,the effects of high-pressure flat membranes on the concentration of salt ions and the removal of pollutants were studied under the conditions of different concentrations of influent TDS,COD and silicon dioxide.The results showed that when the concentration of influent TDS was 35 000-55 000 mg/L,the economic benefit of high-pressure flat membrane operation was the best,and the concentration ratio of high-pressure flat membranes was stable,varying from 3.3 to 3.6.As the concentration of influent organic matter ranged from 100 to 1 800 mg/L,the removal rate of organic matter ranged from 60% to 79%.In addition,the retention rate of high-pressure flat membranes to silicon dioxide was more than 90%.展开更多
Non-isothermal oxidation of brown coal with 5 wt% of Cu(NO3)2, 5 wt% of Ce(NO3)3 and {2.5 wt% Cu(NO3)2 + 2.5 wt% Ce(NO3)3} additives was studied. The introduction of additives was carried out by an incipient wet impre...Non-isothermal oxidation of brown coal with 5 wt% of Cu(NO3)2, 5 wt% of Ce(NO3)3 and {2.5 wt% Cu(NO3)2 + 2.5 wt% Ce(NO3)3} additives was studied. The introduction of additives was carried out by an incipient wet impregnation method to ensure uniform distribution of cerium and copper nitrates within the structure of coal powdery samples (according to SEM and EDX mapping). The samples reactivity was studied in an isothermal oxidation regime at 200 °C (1 h) and by DSC/TGA at 2.5 °C/min heating rate. The additives implementation was found to reduce significantly the oxidation onset temperature (△Ti = 20-55 °C), the samples oxidation delay time (△ti= 2-22 min) and overall duration of the oxidation process (△tc = 8-16 min). The additives efficiency could be graded in accordance with the activation on the coal oxidation in the following row: Cu(NO3)2 >{Cu(NO3)2 + Ce(NO3)3}> Ce(NO3)3. According to the mass spectroscopy, the obtained row of activation correlates well with the initial temperature of the studied nitrate's decomposition (from 190 to 223 °C). A presence of nitrates was found to change significantly the trend of heat release taking place during the oxidation of coal samples (according to DSC/TGA data). The influence of coal morphology and volatiles concern in initial sample on the parameters of the oxidation process was studied as well. Activation energy (Ea) of the coal oxidation was calculated using Coats-Redfern method. Maximum decrease in Ea from 69 to 58 kJ/mol was observed for the samples with Cu(NO3)2. Graphical abstract.展开更多
A novel suspension-floating-circulating fluidized combustion technology is proposed for burning coal slurry fuel in traditional circulating ftuidized bed boilers (CFBB). This technology can solve some existing probl...A novel suspension-floating-circulating fluidized combustion technology is proposed for burning coal slurry fuel in traditional circulating ftuidized bed boilers (CFBB). This technology can solve some existing problems in large- capacity CFBB burning coal slurry. The principles of the suspension-floating-circulating fluidized combustion technology were introduced in detail in this paper. A 130 t/h CFBB was retrofitted based on the technology, and the retrofitted system mainly includes a long-distance transport sub-system, a bed-material conveying sub-system with a wind-seal device invented by the authors, a superheater thermoregulation device using a novel temperature regulator, a return loop flu- idization facility, and a pneumatic ash conveying sub-system with sealed pump. The achieved performance of the retro- fitted CFBB shows that the thermal efficiency is 89.83 %, the combustion efficiency is 96.24 %, and the blending proportion of slurry is 94 %.展开更多
Objectives Tumor necrosis factor-α (TNF-α) may play an important role in host's immune response to mycobacterium tuberculosis (M. tuberculosis) infection. This study was to investigate the association of TNF-α...Objectives Tumor necrosis factor-α (TNF-α) may play an important role in host's immune response to mycobacterium tuberculosis (M. tuberculosis) infection. This study was to investigate the association of TNF-α gene polymorphism with pulmonary tuberculosis (TB) among patients with coal worker's pneumoconiosis (CWP). Methods A case-control study was conducted in 113 patients with confirmed CWP complicated with pulmonary TB and 113 non-TB controls with CWP. They were matched in gender, age, job, and stage of pneumoconiosis. All participants were interviewed with questionnaires and their blood specimens were collected for genetic determination with informed consent. The TNF-α gene polymorphism was determined with polymerase chain reaction of restriction fragment length polymorphism (PCR-RFLP). Frequency of genotypes was assessed for Hardy-Weinberg equilibrium by chi-square test or Fisher's exact probability. Factors influencing the association of individual susceptibility with pulmonary TB were evaluated with logistic regression analysis. Gene-environment interaction was evaluated by a multiplieative model with combined OR. All data were analyzed using SAS version 8.2 software. Results No significant difference in frequency of the TNF-α-308 genotype was found between CWP complicated with pulmonary TB and non-TB controls (2,2=5.44, P=-0.07). But difference in frequency of the TNF-α-308 A allele was identified between them (2,2-5.14, P=0.02). No significant difference in frequencies of the TNF-α-238 genotype and allele (P=0.23 and P=0.09, respectively) was found between cases and controls either, with combined (GG and AA) OR of 3.96 (95% confidence interval of 1.30-12.09) at the -308 locus of the TNF-α gene, as compared to combination of the TNF-α-238 GG and TNF-α-308 GG genotypes. Multivariate-adjusted odds ratio of the TNF-α-238 GG and TNF-α-308 GA genotypes was 1.98 (95% CI of 1.06-3.71) for risk for pulmonary TB in patients with CWP. There was a synergic interaction between the TNF-a-308 GG genotype and body mass index (OR=4.92), as well as an interaction between the TNF-α-308 GG genotype and history of BCG immunization or history of TB exposure. And, the interaction of the TNF-α-238 GG genotype and history of BCG immunization or TB exposure with risk for pulmonary TB in them was also indicated. Conclusions TNF-α-308 A allele is associated with an elevated risk for pulmonary TB, whereas TNF-α-238 A allele was otherwise.展开更多
The present study assesses the concentration,probabilistic risk,source classification,and dietary risk arising from heavy metal(HMs)pollution in agricultural soils affected by coal mining in eastern part of India.Anal...The present study assesses the concentration,probabilistic risk,source classification,and dietary risk arising from heavy metal(HMs)pollution in agricultural soils affected by coal mining in eastern part of India.Analyses of soil and rice plant indicated significantly elevated levels of HMs beyond the permissible limit in the contaminated zones(zone 1:PbSoil:108.24±72.97,CuSoil:57.26±23.91,CdSoil:8.44±2.76,CrSoil:180.05±46.90,NiSoil:70.79±25.06 mg/kg;PbGrain:0.96±0.8,CuGrain:8.6±5.1,CdGrain:0.65±0.42,CrGrain:4.78±1.89,NiGrain:11.74±4.38 mg/kg.zone 2:PbSoil:139.56±69.46,CuSoil:69.89±19.86,CdSoil:8.95±2.57,CrSoil:245.46±70.66,NiSoil:95.46±22.89 mg/kg;PbGrain:1.27±0.84,CuGrain:7.9±4.57,CdGrain:0.76±0.43,CrGrain:8.6±1.58,NiGrain:11.50±2.46 mg/kg)compared to the uncontaminated zone(zone 3).Carcinogenic and non-carcinogenic health risks were computed based on the HMs concentration in the soil and rice grain,with Pb,Cr,and Ni identified as posing a high risk to human health.Monte Carlo simulation,the solubility-free ion activity model(FIAM),and severity adjusted margin of exposure(SAMOE)were employed to predict health risk.FIAM hazard quotient(HQ)values for Ni,Cr,Cd,and Pb were>1,indicating a significant non-carcinogenic risk.SAMOE(risk thermometer)results for contaminated zones ranged from low to moderate risk(CrSAMOE:0.05,and NiSAMOE:0.03).Fuzzy-TOPSIS and variable importance plots(from random forest)showed that Ni and Cr were mostly responsible for the toxicity in the rice plant,respectively.A self-organizing map for source classification revealed common origin for the studied HMs with zone 2 exhibiting the highest contamination.The positive matrix factorization model for the source apportionment identified coal mining and transportation as the predominant sources of HMs.Spatial distribution analysis indicated higher contamination near mining sites as compared to distant sampling sites.Consequently,this study will aid environmental scientists and policymakers controlling HM pollution in agricultural soils near coal mines.展开更多
Mercury pollution in the Three Gorges Reservoir area of P.R.China merits special attention.We investigated into the current situation in the Chongqing part of the Reservoir area,identified the pollution sources and pr...Mercury pollution in the Three Gorges Reservoir area of P.R.China merits special attention.We investigated into the current situation in the Chongqing part of the Reservoir area,identified the pollution sources and proposed some suggestions for the remediation and prevention of mercury pollution in this area.Atmospheric mercury in Chongqing was mainly from coal burning and releases of mercury-containing products such as various types of lights and fever thermometers.Urban drainage in Chongqing and Changshou,and runoffs from the high mercury background area in the lower reaches of the Wujiang River contributed most of the mercury in the water of the Yangtze River.A majority of the blame should be laid on mercury and gold mining in the Wujiang valley.We suggested foresting sloping lands to relieve soil erosion and prevent mercury-bearing soil from running into rivers,educational activities to discourage use of mercury-containing products and improved infrastructure to collect mercury-containing wastes for reducing mercury releases,more facilities for treating wastewater and solid waste to accommodate increased requirements of discharge,and growing selected perennial plants in mercury-contaminated land to absorb the mercury in soil.We also suggested concerted operation of a dedicated water-quality monitoring system,reinforced legislation and an effective administrative mechanism to ensure lasting efforts are invested in curbing mercury releases and restoring mercury contaminated land and water in the Reservoir area.展开更多
This work explored the way to improve hot modulus q/' rupture (HMOR) and refractoriness under load (RUL) by adding mild-calcined coal gangue (MCG) in Al2O3 -SiO2 ultra low cement (ULC) castables, making use o...This work explored the way to improve hot modulus q/' rupture (HMOR) and refractoriness under load (RUL) by adding mild-calcined coal gangue (MCG) in Al2O3 -SiO2 ultra low cement (ULC) castables, making use of the in-situ effect of the MCG during heating-up. The influence of respective additions of 5%, 10% and 1.5% of the MCG powders calcined at 700℃ was investigated on HMOR at 1400 ℃ and RUL of the castables. With increased addition of the MCG, HMOR and RUL become significantly enhanced. At 10% of the MCG addition, HMOR reaches 3 MPa, as compared to 0. 3 MPa in the case of no MCG addition. RUL of the specimens dried at 110 ℃for 24 h can be increased by some 270 ℃ with 10% of the MCG addition. RUL 0.11 the specimens preheated at 1 500℃ for 3 h maintains the growth trend with the MCG addition increasing. The microstructure of the heated castable samples was investigated by means of SEM. The in-situ formed needle-like and interlaced mullite in the matrix is contributive to the tmprovement.展开更多
The characteristics and research methods of terrigenous organic hydrocarbon-generated source rock in coal measures are studied in this thesis. After abundance of organic matters, pyrolysis parameter of rocks and hydro...The characteristics and research methods of terrigenous organic hydrocarbon-generated source rock in coal measures are studied in this thesis. After abundance of organic matters, pyrolysis parameter of rocks and hydrocarbon generated capacity of macerals are basically discussed in coal measures of the Cretaceous Muleng-Chengzihe formation in Suibin depression in Sanjang basin, the hydrocarbon generated grade in coal-genera^ted source rock is ascertained in this depression. At last, we think that it is a main attack prospect in coal-genera^ted hydrocarbons study in the future to research the macerals of coal measures organic source rock and to build a criterion to classify the coal-generated hydrocarbons in Northeast region.展开更多
基金Project(41201492)supported by the National Natural Science Foundation of China
文摘A field investigation was performed to study the content, speciation and mobility of vanadium, as well as microbial response in soil from a stone coal smelting district in Hunan province of China. The results showed that the contents of soil V ranged from 168 to 1538 mg/kg, which exceeded the maximum permissible value of Canadian soil quality for V. The mean soil V content from wasteland area reached 1421 mg/kg, and those from the areas related with slag heap, ore pile and smelting center were 380, 260 and 225 mg/kg, respectively. Based on the results of the modified BCR sequential extraction procedure, V contents in the mobile fractions varied from 19.2 to 637 mg/kg accounting for 7.4%-42.3% of total V, and those of V(+5) species were between 21.9 and 534.0 mg/kg. Soil enzyme activity and microbial basal respiration were adversely affected by high level of soil V. More attention should be paid to soil V pollution and potential hazardous surrounding the stone coal smelting district.
基金Projects 20207014 and 50674084 supported by the National Natural Science Foundation of China
文摘In situ coal gasification poses a potential environmental risk to groundwater pollution although it depends mainly on local hydrogeological conditions. In our investigation,the possible processes of groundwater pollution origi-nating from underground coal gasification (UCG) were analyzed. Typical pollutants were identified and pollution con-trol measures are proposed. Groundwater pollution is caused by the diffusion and penetration of contaminants generated by underground gasification processes towards surrounding strata and the possible leaching of underground residue by natural groundwater flow after gasification. Typical organic pollutants include phenols,benzene,minor components such as PAHs and heterocyclics. Inorganic pollutants involve cations and anions. The natural groundwater flow after gasification through the seam is attributable to the migration of contaminants,which can be predicted by mathematical modeling. The extent and concentration of the groundwater pollution plume depend primarily on groundwater flow ve-locity,the degree of dispersion and the adsorption and reactions of the various contaminants. The adsorption function of coal and surrounding strata make a big contribution to the decrease of the contaminants over time and with the distance from the burn cavity. Possible pollution control measures regarding UCG include identifying a permanently,unsuitable zone,setting a hydraulic barrier and pumping contaminated water out for surface disposal. Mitigation measures during gasification processes and groundwater remediation after gasification are also proposed.
基金Project supported by the Canadian International Development Agency, Canada and the Chinese Academy of Scicences, China (No. KZCX2-413)
文摘To feed an increasing population, large amounts of chemical nitrogen fertilizer have been used to produce much of our food, feed and fiber thereby increasing nitrogen levels in soils, natural waters, crop residues, livestock wastes,and municipal and agricultural wastes, with national and international concern about its potential adverse effects on environmental quality and public health. To understand these phenomena and problems, first the nitrogen cycle and the environment are described. Then recent trends for nitrogen cycling through the food and feed system, N2O emissions from fertilized upland and paddy soils, and NO-3 pollution in ground water in Japan are reported. Finally, mitigation strategies in Japan for reducing N2O emission and NO-3 pollution are proposed, including nitrification inhibitors, controlled release fertilizers, utilization of plant species that could suppress nitrification, utilizing the toposequence, government policy, and appropriate agricultural practices. Of all the technologies presented, use of nitrification inhibitors and controlled release fertilizers are deemed the most important with further development of these aspects of technologies being expected. These practices, if employed worldwide, could help reduce the load, or environmental deterioration, on the Earth's biosphere.
文摘Thick and ultra-thick coal seams are main coal seams for high production rate and high efficiency in Chinese coal mines, which accounts for 44 % of the total minable coal reserve. A fully mechanized top-coal caving mining method is a main underground coal extraction method for ultra-thick coal seams. The coal extraction technologies for coal seams less than 14 m thick were extensively used in China. However, for coal seams with thickness greater than 14 m, there have been no reported cases in the world for underground mechanical extraction with safe performance, high efficiency and high coal recovery ratio. To deal with this case, China Coal Technology & Engineering Group, Datong Coal Mine Group, and other 15 organizations in China launched a fundamental and big project to develop coal mining technologies and equipment for coal seams with thicknesses greater than 14 m. After the completion of the project, a coal extraction method was developed for top-coal caving with a large mining height, as well as a ground control theory for ultra-thick coal seams. In addition, the mining technology for top-coal caving with a large mining height, the ground support technology for roadway in coal seams with a large cross-section, and the prevention and control technology for gas and fire hazards were developed and applied. Furthermore, a hydraulic support with a mining height of 5.2 m, a shearer with high reliability, and auxiliary equipment were developed and manufactured. Practical implication on the technologies and equipment developed was successfully completed at the No. 8105 coal face in the Tashan coal mine, Datong, China. The major achievements of the project are summarized as follows: 1. A top-coal caving method for ultra-thick coal seams is proposed with a cutting height of 5 m and a top-coal caving height of 15 m. A structural mechanical model of overlying strata called cantilever beam-articulated rock beam is established. Based on the model, the load resistance of the hydraulic support with a large mining height for top-coal caving method is determined. With the analysis, the movement characteristics of the top coal and above strata are evaluated during top-coal caving operation at the coal face with a large mining height. Furthermore, there is successful development of comprehensive technologies for preventing and controlling spalling of the coal wall, and the top-coal caving technology with high efficiency and high recovery at the top-coal caving face with a large mining height. This means that the technologies developed have overcome the difficulties in strata control, top-coal caving with high efficiency and high coal recovery, and enabled to achieve a production rate of more than 10 Mtpa at a single top-coal caving face with a large mining height in ultra-thick coal seams; 2. A hydraulic support with 5.2 m supporting height and anti-rockburst capacity, a shearer with high reliability, a scraper conveyor with a large power at the back of face, and a large load and long distance headgate belt conveyor have been successfully developed for a top-coal caving face with large mining height. The study has developed the key technologies for improving the reliability of equipment at the coal face and has overcome the challenges in equipping the top-coal caving face with a large mining height in ultra-thick coal seams; 3. The deformation characteristics of a large cross-section roadway in ultra-thick coal seams are discovered. Based on the findings above, a series of bolt materials with a high yielding strength of 500-830 MPa and a high extension ratio, and cable bolt material with a 1 × 19 structure, large tonnage and high extension ratio are developed. In addition, in order to achieve a safe roadway and a fast face advance, installation equipment for high pre-tension bolt is developed to solve the problems with the support of roadway in coal seams for top-coal caving operation with a large mining height; 4. The characteristics of gas distribution and uneven emission at top-coal caving face with large mining height in ultra-thick coal seams are evaluated. With the application of the technologies of gas drainage in the roof, the difficulties in gas control for high intensive top-coal caving mining operations, known as "low gas content, high gas emission", are solved. In addition, large flow-rate underground mobile equipment for making nitrogen are developed to solve the problems with fire prevention and safe mining at a top-coal caving face with large mining height and production rate of more than 10 Mtpa. A case study to apply the developed technologies has been conducted at the No. 8105 face, the Tashan coal mine in Datong, China. The case study demonstrates that the three units of equipment, i.e., the support, shearer and scraper conveyor, are rationally equipped. Average equipment usage at the coal face is 92.1%. The coal recovery ratio at the coal face is up to 88.9 %. In 2011, the coal production at the No. 8105 face reached 10.849 Mtpa, exceeding the target of 10 Mtpa for a topcoal caving operation with large mining height performed by Chinese-made mining equipment. The technologies and equipment developed provide a way for extracting ultra-thick coal seams. Currently, the technologies and equipment are used in 13 mining areas in China including Datong, Pingshuo, Shendong and Xinjiang. With the exploitation of coal resources in Western China, there is great potential for the application of the technologies and equipment developed.
基金supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.42075107 and 41572090)the Yueqi Scholar fund of China University of Mining and Technology(Beijing)。
文摘Epidemiological studies have suggested that inhalation exposure to indoor ambient air from coal-burning environments is causally associated with respiratory health risks.In order to explore the toxicological mechanisms behind the adverse health effects,the hemolytic activity of PM_(10)(particulate matter with an aerodynamic diameter of 10 um or less)samples collected from homes burning coal in the recognized China"cancer village"Xuanwei were evaluated and matched against their trace elemental contents.The results demonstrated that the hemolytic activity of indoor PM_(10) in coal-burning environments ranged from 4.28%to 5.24%,with a clear positive dose-response relationship.Although low dose samples exhibited a reduced hemolytic activity,PM_(10) could have a toxic effect upon people in a coal-burning indoor environment for extended time periods.The concentrations of analyzed trace elements in PM_(10) samples ranged from 6966 to 12,958 ppm.Among the analyzed elements,Zn,Ti,Ni,Cu,Pb,Ba,Mn,Cr and V were found at higher concentrations and accounted for over 95%of the total elements.The concentrations of total analyzed elements in the PM_(10) samples revealed a significant positive correlation with PM_(10) hemolytic activity.Of the analyzed elements,Zn,Pb and Cs positively correlated with hemolysis,while Li,U and V negatively correlated with the hemolysis of human red blood cells(RBCs).Therefore,the heavy metal elements could be one of the main factors responsible for the hemolytic capacity of indoor PM_(10) in coal-burning environments.
基金funded by a grant from the United Fund of Guizhou Province GovernmentNational Natural Science Foundation of China(No.U1612442-3)the Project of the Education Department of Guizhou Province(Nos.KY 2016011,GZZ201607,and ZDXK201611)
文摘Batch experiments tively evaluate the inhibition were conducted to compara- effects and mechanisms of a low-concentration (1%) proline solution cover on the release of pollutants from high-sulfur coal gangue. High- sulfur coal gangue was continuously immersed in a proline solution and in deionized water (as a control treatment) for 540 days. The results showed that the coal gangue in the control treatment was oxidized and generated leachate with poor water qualities, i.e., the leachate exhibited lower pH values, higher redox potential values, higher pollutant concentrations (804^2-, Fe, Mn, Cu, and Zn), and high levels of acidophilic sulfur-oxidizing bacteria. However, compared to the control treatment, the addition of the proline solution (1%) significantly improved the water quality of the leachate by significantly reducing the Eh values, the pollutant concentrations (804^2-, Fe^2+, Fe, Mn, Cu, and Zn), and the activity of acidophilic sulfur-oxidiz- ing bacteria and by significantly increasing the pH value to neutral. The proline treatment significantly inhibited the oxidation of coal gangue and the release of pollutants, mainly by inhibiting the activity of acidophilic sulfur-ox- idizing bacteria and by altering the heavy metal fractions and the mineralogical characteristics. Therefore, in engi- neering practice, workers should consider using an envi- ronmental friendly aqueous proline solution cover to achieve the in-situ control of pollutant releases from coal gangue dumps.
文摘Over half of the world's population is exposed to household air pollution from the burning of solid fuels at home. Household air pollution from solid fuel use is a leading risk factor for global disease and remains a major public health problem, especially in low- and mid-income countries. This is a particularly serious problem in China, where many people in rural areas still use coal for household heating and cooking. This review focuses on several decades of research carried out in Xuanwei County, Yunnan Province, where household coal use is a major source of household air pollution and where studies have linked household air pollution exposure to high rates of lung cancer. We conducted a series of case-control and cohort studies in Xuanwei to characterize the lung cancer risk in this population and the factors associated with it. We found lung cancer risk to vary substantially between different coal types, with a higher risk associated with smoky(i.e., bituminous) coal use compared to smokeless(i.e., anthracite) coal use. The installation of a chimney in homes resulted in a substantial reduction in lung cancer incidence and mortality. Overall, our research underscores the need among existing coal users to improve ventilation, use the least toxic fuel, and eventually move toward the use of cleaner fuels, such as gas and electricity.
基金This work was financially supported by the National Natural Science Foundation of China(No.21701099)the Science and Technology Innovation Project of Colleges and Universities of Shanxi Province in 2020(No.2020L0721)the Basic Research Project of Shanxi Province,China(No.201801D121267).
文摘In this paper,a novel compound was developed by mixing H_(3)PO_(4)-modified cauliflower leaves hydrochar(CLH)and coal gangue-based Na-X zeolite(ZL).An alkaline soil contaminated with cadmium(Cd)and lead(Pb)was amended through the individual and synergistic application of CLH and ZL(1%CLH,2%CLH,1%ZL,2%ZL and 1%CLH+1%ZL),and Chinese cabbage was grown on it.Individual application of CLH was superior to ZL on decreasing the pH of alkaline soil and increasing soil available phosphorus(Olsen-P)and soil organic matter(SOM).In contrast,their combined application significantly improved the soil cation exchange capacity(CEC).Besides,the 1%CLH+1%ZL was the most efficient treatment in decreasing diethylenetriamine pentaacetate(DTPA)-extractable Cd/Pb and concentrations of these two metals in cabbage root and shoot.Their synergistic application could better increase Cd and Pb immobilization and cabbage yield than their alone application.Furthermore,the immobilization of Pb for all treatments was higher than that of Cd.The synergistic immobilization mechanism of CLH and ZL reflected that the CLH precipitated and complexed with these two metals,which may block the pores of hydrochar or wrap on the surface of hydrochar.So the continuous adsorption and complexation were prevented.Nevertheless,ZL could probably alleviate this obstacle.This finding provides helpful information about using CLH combined with ZL as a soil stabilizer to immobilize heavy metals in contaminated alkaline soil.
文摘In the process of using high-pressure flat membranes to treat coal chemical wastewater,the effects of high-pressure flat membranes on the concentration of salt ions and the removal of pollutants were studied under the conditions of different concentrations of influent TDS,COD and silicon dioxide.The results showed that when the concentration of influent TDS was 35 000-55 000 mg/L,the economic benefit of high-pressure flat membrane operation was the best,and the concentration ratio of high-pressure flat membranes was stable,varying from 3.3 to 3.6.As the concentration of influent organic matter ranged from 100 to 1 800 mg/L,the removal rate of organic matter ranged from 60% to 79%.In addition,the retention rate of high-pressure flat membranes to silicon dioxide was more than 90%.
文摘Non-isothermal oxidation of brown coal with 5 wt% of Cu(NO3)2, 5 wt% of Ce(NO3)3 and {2.5 wt% Cu(NO3)2 + 2.5 wt% Ce(NO3)3} additives was studied. The introduction of additives was carried out by an incipient wet impregnation method to ensure uniform distribution of cerium and copper nitrates within the structure of coal powdery samples (according to SEM and EDX mapping). The samples reactivity was studied in an isothermal oxidation regime at 200 °C (1 h) and by DSC/TGA at 2.5 °C/min heating rate. The additives implementation was found to reduce significantly the oxidation onset temperature (△Ti = 20-55 °C), the samples oxidation delay time (△ti= 2-22 min) and overall duration of the oxidation process (△tc = 8-16 min). The additives efficiency could be graded in accordance with the activation on the coal oxidation in the following row: Cu(NO3)2 >{Cu(NO3)2 + Ce(NO3)3}> Ce(NO3)3. According to the mass spectroscopy, the obtained row of activation correlates well with the initial temperature of the studied nitrate's decomposition (from 190 to 223 °C). A presence of nitrates was found to change significantly the trend of heat release taking place during the oxidation of coal samples (according to DSC/TGA data). The influence of coal morphology and volatiles concern in initial sample on the parameters of the oxidation process was studied as well. Activation energy (Ea) of the coal oxidation was calculated using Coats-Redfern method. Maximum decrease in Ea from 69 to 58 kJ/mol was observed for the samples with Cu(NO3)2. Graphical abstract.
文摘A novel suspension-floating-circulating fluidized combustion technology is proposed for burning coal slurry fuel in traditional circulating ftuidized bed boilers (CFBB). This technology can solve some existing problems in large- capacity CFBB burning coal slurry. The principles of the suspension-floating-circulating fluidized combustion technology were introduced in detail in this paper. A 130 t/h CFBB was retrofitted based on the technology, and the retrofitted system mainly includes a long-distance transport sub-system, a bed-material conveying sub-system with a wind-seal device invented by the authors, a superheater thermoregulation device using a novel temperature regulator, a return loop flu- idization facility, and a pneumatic ash conveying sub-system with sealed pump. The achieved performance of the retro- fitted CFBB shows that the thermal efficiency is 89.83 %, the combustion efficiency is 96.24 %, and the blending proportion of slurry is 94 %.
基金supported by grants from China National Programs for Science and Technology Development (Grant No. 2003BA712A11-24)Scientific Research Fund of North China Coal Medical College (Grant No. 2005-14)
文摘Objectives Tumor necrosis factor-α (TNF-α) may play an important role in host's immune response to mycobacterium tuberculosis (M. tuberculosis) infection. This study was to investigate the association of TNF-α gene polymorphism with pulmonary tuberculosis (TB) among patients with coal worker's pneumoconiosis (CWP). Methods A case-control study was conducted in 113 patients with confirmed CWP complicated with pulmonary TB and 113 non-TB controls with CWP. They were matched in gender, age, job, and stage of pneumoconiosis. All participants were interviewed with questionnaires and their blood specimens were collected for genetic determination with informed consent. The TNF-α gene polymorphism was determined with polymerase chain reaction of restriction fragment length polymorphism (PCR-RFLP). Frequency of genotypes was assessed for Hardy-Weinberg equilibrium by chi-square test or Fisher's exact probability. Factors influencing the association of individual susceptibility with pulmonary TB were evaluated with logistic regression analysis. Gene-environment interaction was evaluated by a multiplieative model with combined OR. All data were analyzed using SAS version 8.2 software. Results No significant difference in frequency of the TNF-α-308 genotype was found between CWP complicated with pulmonary TB and non-TB controls (2,2=5.44, P=-0.07). But difference in frequency of the TNF-α-308 A allele was identified between them (2,2-5.14, P=0.02). No significant difference in frequencies of the TNF-α-238 genotype and allele (P=0.23 and P=0.09, respectively) was found between cases and controls either, with combined (GG and AA) OR of 3.96 (95% confidence interval of 1.30-12.09) at the -308 locus of the TNF-α gene, as compared to combination of the TNF-α-238 GG and TNF-α-308 GG genotypes. Multivariate-adjusted odds ratio of the TNF-α-238 GG and TNF-α-308 GA genotypes was 1.98 (95% CI of 1.06-3.71) for risk for pulmonary TB in patients with CWP. There was a synergic interaction between the TNF-a-308 GG genotype and body mass index (OR=4.92), as well as an interaction between the TNF-α-308 GG genotype and history of BCG immunization or history of TB exposure. And, the interaction of the TNF-α-238 GG genotype and history of BCG immunization or TB exposure with risk for pulmonary TB in them was also indicated. Conclusions TNF-α-308 A allele is associated with an elevated risk for pulmonary TB, whereas TNF-α-238 A allele was otherwise.
文摘The present study assesses the concentration,probabilistic risk,source classification,and dietary risk arising from heavy metal(HMs)pollution in agricultural soils affected by coal mining in eastern part of India.Analyses of soil and rice plant indicated significantly elevated levels of HMs beyond the permissible limit in the contaminated zones(zone 1:PbSoil:108.24±72.97,CuSoil:57.26±23.91,CdSoil:8.44±2.76,CrSoil:180.05±46.90,NiSoil:70.79±25.06 mg/kg;PbGrain:0.96±0.8,CuGrain:8.6±5.1,CdGrain:0.65±0.42,CrGrain:4.78±1.89,NiGrain:11.74±4.38 mg/kg.zone 2:PbSoil:139.56±69.46,CuSoil:69.89±19.86,CdSoil:8.95±2.57,CrSoil:245.46±70.66,NiSoil:95.46±22.89 mg/kg;PbGrain:1.27±0.84,CuGrain:7.9±4.57,CdGrain:0.76±0.43,CrGrain:8.6±1.58,NiGrain:11.50±2.46 mg/kg)compared to the uncontaminated zone(zone 3).Carcinogenic and non-carcinogenic health risks were computed based on the HMs concentration in the soil and rice grain,with Pb,Cr,and Ni identified as posing a high risk to human health.Monte Carlo simulation,the solubility-free ion activity model(FIAM),and severity adjusted margin of exposure(SAMOE)were employed to predict health risk.FIAM hazard quotient(HQ)values for Ni,Cr,Cd,and Pb were>1,indicating a significant non-carcinogenic risk.SAMOE(risk thermometer)results for contaminated zones ranged from low to moderate risk(CrSAMOE:0.05,and NiSAMOE:0.03).Fuzzy-TOPSIS and variable importance plots(from random forest)showed that Ni and Cr were mostly responsible for the toxicity in the rice plant,respectively.A self-organizing map for source classification revealed common origin for the studied HMs with zone 2 exhibiting the highest contamination.The positive matrix factorization model for the source apportionment identified coal mining and transportation as the predominant sources of HMs.Spatial distribution analysis indicated higher contamination near mining sites as compared to distant sampling sites.Consequently,this study will aid environmental scientists and policymakers controlling HM pollution in agricultural soils near coal mines.
基金the Natural Science Foundation of China under the Grant No.20377054
文摘Mercury pollution in the Three Gorges Reservoir area of P.R.China merits special attention.We investigated into the current situation in the Chongqing part of the Reservoir area,identified the pollution sources and proposed some suggestions for the remediation and prevention of mercury pollution in this area.Atmospheric mercury in Chongqing was mainly from coal burning and releases of mercury-containing products such as various types of lights and fever thermometers.Urban drainage in Chongqing and Changshou,and runoffs from the high mercury background area in the lower reaches of the Wujiang River contributed most of the mercury in the water of the Yangtze River.A majority of the blame should be laid on mercury and gold mining in the Wujiang valley.We suggested foresting sloping lands to relieve soil erosion and prevent mercury-bearing soil from running into rivers,educational activities to discourage use of mercury-containing products and improved infrastructure to collect mercury-containing wastes for reducing mercury releases,more facilities for treating wastewater and solid waste to accommodate increased requirements of discharge,and growing selected perennial plants in mercury-contaminated land to absorb the mercury in soil.We also suggested concerted operation of a dedicated water-quality monitoring system,reinforced legislation and an effective administrative mechanism to ensure lasting efforts are invested in curbing mercury releases and restoring mercury contaminated land and water in the Reservoir area.
文摘This work explored the way to improve hot modulus q/' rupture (HMOR) and refractoriness under load (RUL) by adding mild-calcined coal gangue (MCG) in Al2O3 -SiO2 ultra low cement (ULC) castables, making use of the in-situ effect of the MCG during heating-up. The influence of respective additions of 5%, 10% and 1.5% of the MCG powders calcined at 700℃ was investigated on HMOR at 1400 ℃ and RUL of the castables. With increased addition of the MCG, HMOR and RUL become significantly enhanced. At 10% of the MCG addition, HMOR reaches 3 MPa, as compared to 0. 3 MPa in the case of no MCG addition. RUL of the specimens dried at 110 ℃for 24 h can be increased by some 270 ℃ with 10% of the MCG addition. RUL 0.11 the specimens preheated at 1 500℃ for 3 h maintains the growth trend with the MCG addition increasing. The microstructure of the heated castable samples was investigated by means of SEM. The in-situ formed needle-like and interlaced mullite in the matrix is contributive to the tmprovement.
文摘The characteristics and research methods of terrigenous organic hydrocarbon-generated source rock in coal measures are studied in this thesis. After abundance of organic matters, pyrolysis parameter of rocks and hydrocarbon generated capacity of macerals are basically discussed in coal measures of the Cretaceous Muleng-Chengzihe formation in Suibin depression in Sanjang basin, the hydrocarbon generated grade in coal-genera^ted source rock is ascertained in this depression. At last, we think that it is a main attack prospect in coal-genera^ted hydrocarbons study in the future to research the macerals of coal measures organic source rock and to build a criterion to classify the coal-generated hydrocarbons in Northeast region.