Exploitation contradictions concerning multi-energy resources among coal, gas, oil, and uranium: A case study in the ordos basin (Western North China Craton and Southern Side of Yinshan Mountains)

The particular “rich coal, meager oil, and deficient gas” energy structure of China determines its high degree of dependence on coal resources. After over 100 years of high-intensity mining activities in Northeast China, East Region, and the Southern Region, coal mining in these areas is facing a series of serious problems, which force China’s energy exploitation map to be rewritten. New energy bases will move to the western and northern regions in the next few years. However, overlapping phenomena of multiple resources are frequently encountered. Previous exploitation mainly focused on coal mining, which destroys many mutualistic and accompanying resources, such as uranium, gas, and oil. Aiming at solving this unscientific development mode, this research presents a case study in the Ordos Basin, where uranium, coal, and gas/oil show a three-dimensional overlapping phenomenon along the vertical downward direction. The upper uranium and lower coal situation in this basin is remarkable; specifically, coal mining disturbs the overlaying aquifer, thus requiring the uranium to be leached first. The technical approach must be sufficiently reliable to avoid the leakage of radioactive elements in subsequent coal mining procedures. Hence, the unbalanced injection and extraction of uranium mining is used to completely eradicate the discharged emissions to the environment. The gas and oil are typically not extracted because of their deep occurrence strata and their overlapping phenomenon with coal seams. Use of the integrated coal and gas production method is recommended, and relevant fracturing methods to increase the gas migrating degree in the strata are also introduced. The results and recommendations in this study are applicable in some other areas with similarities

Development of water quality model in the Satilla River Estuary, Georgia

A coupled three-dimensional physical and water quality model was developed for the Satilla River Estuary, Georgia. The physical model is a modified ECOM-si version with inclusion of flooding/draining process over the intertidal salt marsh. The water quality model is a modified WASP5 with inclusion of nutrient fluxes from the bottom sediment layer. The coupled model was driven by tidal forcings at the open boundary in the inner shelf of the South Atlantic Bight (SAB) and real-time river discharge at the upstream of the estuary. The initial condition for salinity was specified using the field measurement data taken along the estuary. The water quality components were assumed as constant values everywhere at the initial, with assumption that the spatial and temporal variations of these variables were caused by physical-biological-chemical interactions under strong tidal mixing environment. The model-predicted concentrations of inorganic nutrients (ammonium, nitrate plus nitrite, and ortho-phosphorus), chlorophyll-a, and dissolved oxygen (DO) in an along-estuary transect were in reasonable agreement with observational data. Process studies suggest that the intertidal salt marsh acts as a main sink for particulate materials and a major consumer of DO. The low DO concentration in the Satilla River Estuary was mainly due to high sediment oxygen demand (SOD) over the intertidal salt marsh. This feature is the nature of the estuarine-salt marsh ecosystem with nothing related to anthropogenic activities. Tidal mixing-induced bottom resuspension process played a critical role in supplying the nutrients in the water column in addition to the nitrification process. © 2004 Elsevier B.V. All rights reserved

Application of a Backfilling Method in Coal Mining to Realise an Ecologically Sensitive “Black Gold” Industry

China, as the largest coal-producing and -consuming country in the world, is highly dependent on its coal industry, or “Black Gold” industry, for the national energy and economy. The consequent environmental crises, however, have persisted for decades, and the most serious effect is surface subsidence induced by underground mining. Underground coal excavation in China has ignored this problem for thousands of years, even though it causes conspicuous damage to the surface ecosystem and construction projects due to the subsidence of overlying strata. This study recommends paste backfilling to replace the space originally occupied by coal resources to avoid such subsidence and proposes backfilling schemes for two mainstream mining methods used in China’s collieries, namely, continuous mining and fully mechanised coal mining. These methodologies have been successfully implemented in some collieries, and the gob area can be backfilled immediately to prevent surface subsidence. To promote an ecological ideology when conflict exists between economic profits and environmental protection, experience from developed countries should be considered, support and appropriate legislation from the government are essential, and the perspective of colliery managers should be taken into account, and further in-depth study on strata subsidence and backfilling material must be pursued

Soman hydrolysis catalysed by hypochlorite ions

Sarin (GB) and soman (GD) are severely toxic nerve agents that react slowly in water, resulting in long-term poisoning of the water and a serious threat to personnel. Some ions can catalyse GB and GD hydrolysis in water; the relevant research for GB is detailed, whereas that for GD is relatively less so. In this paper, GD hydrolysis catalysed by hypochlorite (ClO−) ions was studied via kinetic experiments. A fluorite-ion-specific electrode was used to monitor F− ions produced, allowing the rate constant and half-life of the GD hydrolysis to be calculated. The results showed that ClO− ions promote GD hydrolysis well; the higher the concentration of ClO−, the faster the GD was hydrolysed. In NaClO solution at pH 8.0 with 3.22×10–3 M ClO− ions, the half-life of GD hydrolysis was 82.5 s, about 875 times shorter than that in water at pH 8.0. The rate constant for catalysis of GD hydrolysis by ClO- ions ++(kc1

Model Development and Hindcast Simulations of NOAA’s Integrated Northern Gulf of Mexico Operational Forecast System

NOAA’s National Ocean Service is upgrading three existing northern Gulf of Mexico (GOM) operational nowcast/forecast systems (OFS) by integrating them into one single system (INGOFS) and developing additional domain coverage to encompass the lower Mississippi River, Lake Pontchartrain, Texas coastal embayments, and Mexican coastal waters. The system will produce real-time nowcast and short-range forecast guidance for water levels, 3-dimensional currents, water temperature, and salinity. INGOFS will be implemented using the Finite Volume Community Ocean Model (FVCOM). This paper describes the model configuration and results from a one-year (2 August 2016⁻1 August 2017) hindcast simulation. The model grid is composed of about 300,000 nodes and 600,000 elements, and has a spatial resolution ranging from 45 m near the coast to around 10 km on the open ocean boundary. It uses the FVCOM wetting and drying feature, the quadratic bottom friction scheme, and the two-equation model of the Mellor-Yamada Level 2.5 turbulence closure scheme. The hindcast results of water levels, surface temperatures, and salinity were verified by comparing the model time series with in situ observations. The root-mean-squared errors are about 0.08 m for water levels, about 1.1 °C for temperatures, and about 3.7 psu for salinity. The hindcast configuration will be further tested in a nowcast/forecast environment for a one-year period. The upgraded system is anticipated to be in operational production in mid-2020

Pretreatment Method for Peroxides Decon Water Before GC Analysis of HD, VX, and GD

Peroxides like sodium percarbonate (SPC) and sodium percarbonate-acetylsalicylic acid (SPC-Aspirin) can be used to destroy chemical warfare agents (CWAs) such as HD, VX and GD due to the former's oxidation capacity and nucleophilicity. In this paper, experiments were performed to study factors affecting CWAs recovery from peroxides decontaminant water (decon water) and develop the method to recover residual CWAs from peroxides decon water before GC analysis. Results showed that extraction solvent and neutralization were important for high CWA recovery. DCM was more suitable than PE as extractant for most samples except SPC decon water containing HD. Sodium sulfite could well neutralized decontaminant reactivity in decon water. When suitable conditions of simultaneous neutralization and extraction were carried, CWAs recovery from SPC decon water were greater than 90% at a concentration range of 10 mg l-1 to 10000 mg l-1, the recovery of HD, VX and GD from SPC-Aspirin decon water was more than 90%, 80% and 95% respectively at a concentration range of 100 mg l-1 to 10000 mg l-1, while CWAs recovery were relatively lower from SPC-Aspirin decon water with CWAs concentration of 10 mg l-1 due to the degradation of CWAs during pretreatment processes

Study on detoxification property of alkaline-modified MoO

The decontaminant activated by MoO42- (MoO42--H2O2) suitable for subzero environment shows strong oxidizing ability and weak nucleophilicity due to its acid. In this paper, in order to improve nucleophilicity and retain oxidation of MoO42--H2O2 as far as possible, NH3 and NaOH were used as alkaline modifiers, and PhSMe was used as a simulant of HD to study the oxidation rate and products of sulfides by alkaline-modified MoO42--H2O2 below zero. Results showed that the reaction rate constants decreased with the increase of pH in both NH3 and NaOH modified MoO42--H2O2 at -20°C, and the relative ratio of sulfone to sulfoxide increased especially at pH>9. The reaction activation energy Ea of PhSMe oxidation in the alkaline-modified MoO42--H2O2 decontaminants was lower than that in the MoO42--H2O2 decontaminant, which indicated that the sensitivity of the oxidation reaction rate to temperature in MoO42--H2O2 was reduced after modification

Exploitation Contradictions Concerning Multi-Energy Resources among Coal, Gas, Oil, and Uranium: A Case Study in the Ordos Basin (Western North China Craton and Southern Side of Yinshan Mountains)

The particular “rich coal, meager oil, and deficient gas” energy structure of China determines its high degree of dependence on coal resources. After over 100 years of high-intensity mining activities in Northeast China, East Region, and the Southern Region, coal mining in these areas is facing a series of serious problems, which force China’s energy exploitation map to be rewritten. New energy bases will move to the western and northern regions in the next few years. However, overlapping phenomena of multiple resources are frequently encountered. Previous exploitation mainly focused on coal mining, which destroys many mutualistic and accompanying resources, such as uranium, gas, and oil. Aiming at solving this unscientific development mode, this research presents a case study in the Ordos Basin, where uranium, coal, and gas/oil show a three-dimensional overlapping phenomenon along the vertical downward direction. The upper uranium and lower coal situation in this basin is remarkable; specifically, coal mining disturbs the overlaying aquifer, thus requiring the uranium to be leached first. The technical approach must be sufficiently reliable to avoid the leakage of radioactive elements in subsequent coal mining procedures. Hence, the unbalanced injection and extraction of uranium mining is used to completely eradicate the discharged emissions to the environment. The gas and oil are typically not extracted because of their deep occurrence strata and their overlapping phenomenon with coal seams. Use of the integrated coal and gas production method is recommended, and relevant fracturing methods to increase the gas migrating degree in the strata are also introduced. The results and recommendations in this study are applicable in some other areas with similarities