Yijun Yang

• Doctor of Philosophy
• Professor (Associate) at China University of Geosciences

The increase with years of kidney stone prevalence has become a serious public health problem worldwide. The geographical distribution pattern of kidney stone (known as “stone belt”) clearly indicates the critical role of environmental exposure in its formation, which has long been an underestimated risk factor in studying the development of kidney...

Geogenic arsenic (As) contaminated groundwater has been widely accepted associating with dissolved organic matter (DOM) in aquifers, but the underlying enrichment mechanism at molecular-level from a thermodynamic perspective is poorly evidenced. To fill this gap, we contrasted the optical properties and molecular compositions of DOM coupled with hy...

High As groundwater has been reported in aquifers comprising Late Pleistocene and Holocene sediments worldwide, and could be due to the depositional environment and sedimentological processes. To investigate the paleoenvironment and chemical weathering as mechanisms controlling the fate of As, this study characterized the elemental, clay mineral, a...

The biodegradation of organic matter triggers the reductive dissolution of iron oxides with the transformation among iodine species has been mostly accepted as the key iodine mobilization process in groundwater system. However, molecular characteristics of natural organic matter (NOM) and their interaction with iron oxides on geogenic iodine enrich...

Intake of groundwater with arsenic (As) concentrations exceeding the World Health Organization standard of 10 μg L⁻¹ adversely impacts over 100 million people worldwide. Geogenic As contaminated groundwater within central Yangtze River Basin has recently been reported, but the variations within different depths of aquifers are not commonly observed...

Dissolved organic matter (DOM) plays critical roles in biogeochemistry of arsenic in groundwater systems. To characterize the spatial-temporal variations of groundwater DOM and its impacts on arsenic dynamics, surface water and shallow groundwater from two different depths were collected during monsoon and non-monsoon periods in Jianghan Plain, cen...

Urinary Stone Disease (USD) or urolithiasis has plagued humans for centuries, and its prevalence has increased over the past few decades. Although USD pathology could vary significantly among individuals, previous qualitative assessments using limited survey data demonstrated that the prevalence of USD might exhibit a distinctive geographical distr...

In order to reveal the pattern of spatial distribution of iodine in groundwater at North China Plain (NCP), a total of 136 groundwater samples were collected along the regional groundwater flow paths. The results showed that groundwater iodine ranged from 1.51 to 1106μg/L, and 31.4% of the samples have iodine concentrations higher than 150μg/L. Hig...

In order to identify the effects of groundwater colloids on iodine mobilization in aquifer system, nine groundwater samples were in-situ filtered through successive pore-sized membranes (0.45 μm, 30 kDa and 5 kDa) using filtration technique under N2 atmosphere. Obvious decrease in groundwater iodine, Fe, Al and DOC was observed in the larger pore-s...

To better understand the enrichment of fluoride and iodine in groundwater at North China Plain (NCP), speciation analysis and geochemical modeling were conducted to identify the key hydrochemical processes controlling their mobilization in groundwater system. Groundwater fluoride and iodine concentrations ranged from 0.18 to 5.59 mg/L and from 1.51...

Introduction: Many secondary metabolites in plants are labile compounds which under environmental stress, are difficult to detect and track due to the lack of rapid in situ identification techniques, making plant metabolomics research difficult. Therefore, developing a reliable analytical method for rapid in situ identification of labile compounds...

Iowaite with designed Mg/Fe ratios of 2.5, 3.0, 3.5, 4.0 and 5.0 was synthesized for treating both arsenate- and arsenite-spiked waters in this study. The experimental results show that there is a positive correlation between the molar ratio of Fe to Mg of synthetic iowaite and its arsenic uptake capacity. The dearsenication mechanisms were investi...

A method to selectively and sensitively detect organic iodine compounds and identify their structures has been developed using liquid chromatography-high resolution mass spectrometry (LC-HRMS). Using extracted ion chromatograms of product ions (iodine ion) collected on a rapid scanning quadrupole orbitrap mass spectrometer, the retention times of t...

Reservoir temperature estimation is vitally important for assessing the exploitation potential of a geothermal field. In this study, the concentrations of major chemical constituents in geothermal water sampled from boiling and hot springs in the Tengchong hydrothermal area were measured, and quartz and cationic solutes geothermometers were used to...