The introduction of nitrogen from coal into the surface watershed nitrogen cycle due to coal mining activity.

Human activity has doubled the turnover rate of the terrestrial nitrogen cycle, leading to a series of environmental problems. A little-studied nitrogen source in terrestrial and aquatic environments is the nitrogen release associated with rock strata. Southwest China features the largest continuous karsts in the world, featuring a fragile ecological environment but abundant coal resources.

The non-coevolution of DIC and alkalinity and the CO degassing in a karst river affected by acid mine drainage in Southwest China.

Dissolved inorganic carbon (DIC) in mine water generated during coal mining is a large and potential source of atmospheric CO, however its geochemical behaviors under the influence of AMD in relation to CO degassing and carbonate buffering are not well known. In this study, water temperature, pH, DO, alkalinity, Ca concentration, and the carbon isotope of DIC were measured monthly from November 2020 to November 2021 and carbonate chemistry and CO emission flux were calculated to reveal the processes of DIC evolution and CO degassing from the Chetian River draining a karst region, which is materially affected by the input of large quantities of AMD. The results showed that carbonate erosion, the mineralization of terrestrial organic matter, and domestic sewage input are all identified to contribute DIC to different degrees to the river.

The effect of mining development in karst areas on water acidification and fluorine enrichment in surface watersheds.

High fluoride water is a crucial driving factor for endemic fluorosis. As an important research content of hydrogeochemistry, the enrichment of fluorine in alkaline water has received a fair amount of scholarly attention, but the understanding of the migration and enrichment of fluorine in acid mine drainage (AMD) in karst area remains very limited. An analysis of 13 consecutive periods of hydrochemical samples (312 samples in total) revealed that the weathering of carbonates and sulfide-rich coal measures induced a pH as low as 2.

Rare earth element geochemistry of Middle Devonian reefal limestones of the Dianqiangui Basin, South China: implications for nutrient sources and expansion of the reef ecosystem.

The Givetian Age witnessed the greatest expansion of stromatoporoid-coral reefs from low to higher latitudes of the Phanerozoic. Multi-proxy seawater surface temperature reconstruction suggests the establishment of a super-greenhouse climate as a major reason for reef expansion, yet many questions remain. This article presents the results of a rare earth element and yttrium (herein referred to as REY, derived from REE + Y) geochemical study as well as mineralogy and oxygen isotope values of two well-documented Middle Givetian reefal carbonate sections (Jiwozhai and Buzhai) of the Jiwozhai Formation of South China.

Rhizosphere Microbial Communities and Geochemical Constraining Mechanism of Antimony Mine Waste-Adapted Plants in Southwestern China.

Antimony (Sb) and arsenic (As) are two hazardous metalloid elements, and the biogeochemical cycle of Sb and As can be better understood by studying plant rhizosphere microorganisms associated with Sb mine waste. In the current study, samples of three types of mine waste-Sb mine tailing, waste rocks, and smelting slag-and associated rhizosphere microorganisms of adapted plants were collected from Qinglong Sb mine, southwest China. 16S rRNA was sequenced and used to study the composition of the mine waste microbial community.

Secondary Sulfate Minerals from Pyrite Oxidation in Lanmuchang Hg-Tl Deposit, Southwest Guizhou Province, China: Geochemistry and Environmental Significance.

Thallium (Tl) is a highly toxic trace metal posing a significant threat to human health. Tl pollution in soils and chronic Tl poisoning related to Tl-rich sulfides weathering in the Lanmuchang mine of southwest Guizhou province, China, have been intensively studied in recent years. And yet, there are few studies on the role of secondary sulfate minerals associated with Tl mobility in this area.

Effects of Organic Fertilizers on Cd Activity in Soil and Cd Accumulation in Rice in Three Paddy Soils from Guizhou Province.

A greenhouse pot experiment was conducted to investigate the effects of organic fertilizer application on Cd activity in soil and Cd accumulation in rice in paddy soils with different levels of contamination from varying Cd sources in Guizhou Province (the soil types are NJ, which is a soil with a high geological background of Cd; and QX and JZ, which are anthropogenic Cd-polluted soils). The application of organic fertilizer increased the content of organic matter in the soil and reduced the concentration of acetic acid-extractable Cd in QX and JZ paddy soils. Organic fertilizer increased rice yields and significantly decreased the Cd concentration in brown rice.

Spatial Distribution and Environmental Risk of Arsenic and Antimony in Soil Around an Antimony Smelter of Qinglong County.

The purpose of this study was to investigate the distribution of arsenic (As) and antimony (Sb) in soils around an antimony smelter at Qinglong together with the soil pollution levels and potential ecological risk. The results show that (1) total concentrations of As (23 ~ 539 mg/kg) and Sb (19.7 ~ 5681 mg kg) were higher than the Guizhou province-level background values (As, 20; Sb, 2.

Effects of mining activities on evolution of water chemistry in coal-bearing aquifers in karst region of Midwestern Guizhou, China: evidences from δC of dissolved inorganic carbon and δS of sulfate.

The generation of acid mine drainage (AMD) may accelerate watershed erosion and promote the migration of heavy metals, then threaten local ecosystems such as aquatic life and even human health. Previous studies have focused primarily on influence of AMD in surface environment. In order to reveal the acidizing processes in karst high-sulfur coalfield in Southwest China, this study, by contrast, focused on the hydrogeochemical evolution process and acidification mechanism of mine water in Zhijin coalfield, western Guizhou Province.