Recent progress on in-situ chemical oxidation for the remediation of petroleum contaminated soil and groundwater.

Accidental oil leaks and spills can often result in severe soil and groundwater pollution. In situ chemical oxidation (ISCO) is a powerful and efficient remediation technology. In this review, the applications and recent advances of three commonly applied in-situ oxidants (hydrogen peroxide, persulfate, and permanganate), and the gap in remediation efficiency between lab-scale and field-scale applications is critically assessed.

Novelelectronic health records applied for prediction of pre-eclampsia: Machine-learning algorithms.

Objective: To predict risk of pre-eclampsia (PE) in women using machine learning (ML) algorithms, based on electronic health records (EHR) collected at the early second trimester.

Study Design: A total of 3759 cases of pregnancy who received antenatal care at Xinhua hospital Chongming branch Affiliated to Shanghai Jiaotong University were included in this retrospective EHR-based study. Thirty-eight candidate clinical parameters routinely available at the first visit in antenatal care were collected by manual chart review.

Redox properties and dechlorination capacities of landfill-derived humic-like acids.

Electron transfer capacities (ETC) of humic-like acids (HLA) and their effects on dechlorination are dependent on their redox-active properties. Aging and minerals can affect the chemical compositions and structures of HLA. However, the underlying mechanism and the impacts on the dechlorination capacities of HLA are poorly understood.

Redox properties of compost-derived organic matter and their association with polarity and molecular weight.

Compost-derived dissolved organic matter (DOM), which has a wide distribution of molecular weight (MW) and polarity, has a potential application in the remediation of the contaminated soil due to its redox-active functional groups. Composting treatment can change the MW and polarity of the DOM through microbial transformation and degradation. However, the relationship between the redox properties of compost-derived DOM and its MW and polarity is still unclear.

[Spectral Characteristics of Dissolved Organic Matter in Landfill Groundwater].

Landfills have been the most common methods of organized waste disposal in China posing an incredible groundwater pollution threat. Dissolved organic matter (DOM) can be used to trace the source, species and migration of contaminants in groundwater, and the investigations of its composition, structure, and distribution play a role in environmental protection. This study investigated the DOM source, composition, and molecular structure in groundwater at landfills for different years of operation, and explored the dynamics of groundwater DOM evolution over time, usingmodern spectroscopy in combination with multivariate statistical analysis.

[Analysis of the Characteristics of Groundwater Quality in a Typical Vegetable Field, Northern China].

This study explores the impact of facility farming on the origin and composition of groundwater and on the distribution characteristics of inorganic salts, heavy metals, and dissolved organic matter in groundwater in a typical greenhouse vegetable planting area in North China plains. The methods used include conventional analysis, UV-Visible, and fluorescence spectroscopy combined with parallel factor analysis, principle components analysis, and two-dimensional (2D) hetero-spectral correlation spectra techniques. The results showed that the hydrochemistry type of groundwater in the facility vegetable field was Cl-SO, the nitrogen content was higher than the National Groundwater V Class Quality Standard (GB/T14848-93), and the heavy metal content was lower than the National Drinking Water Standard (GB5749-2006).

Investigating the composition characteristics of dissolved and particulate/colloidal organic matter in effluent-dominated stream using fluorescence spectroscopy combined with multivariable analysis.

Fluorescence excitation-emission matrix (EEM) spectroscopy combined with principal component analysis (PCA) and parallel factor analysis (PARAFAC) were used to investigate the compositional characteristics of dissolved and particulate/colloidal organic matter and its correlations with nitrogen, phosphorus, and heavy metals in an effluent-dominated stream, Northern China. The results showed that dissolved organic matter (DOM) was comprised of fulvic-like, humic-like, and protein-like components in the water samples, and fulvic-like substances were the main fraction of DOM among them. Particulate/colloidal organic matter (PcOM) consisted of fulvic-like and protein-like matter.

[Pollution Characteristics Analysis in Shallow Groundwater of Typical Farmland Area, Southern China].

To analyze the characteristics of shallow groundwater pollution in farmland ecosystem in south China and geochemical behavior of major pollutants in the environment, taking the typical farmland in Taihu River Basin as the object, combined with conventional analysis method of the water quality, fluorescence spectrum technology and multivariate statistical analysis method, the characteristics of the water chemistry in shadow groundwater and the distribution of the dissolved organic matter and the heavy metals were studied. The reasons for all the phenomena were researched as well. The result showed that, water body in the study area showed the reducing atmosphere, the main chemical types of shallow groundwater were HCO-Ca·Na, and compared to the contents of NH-N and NH-N, the concentration of NH-N was higher.

[Evolution of Dissolved Organic Matter Properties in a Constructed Wetland of Xiao River, Hebei].

The evolution of water DOC and COD, and the source, chemical structure, humification degree and redox of dissolved organic matter (DOM) in a constructed wetland of Xiao River, Hebei, was investigated by 3D excitation--emission matrix fluorescence spectroscopy coupled with ultraviolet spectroscopy and chemical reduction, in order to explore the geochemical processes and environmental effects of DOM. Although DOC contributes at least 60% to COD, its decrease in the constructed wetland is mainly caused by the more extensive degradation of elements N, H, S, and P than C in DOM, and 65% is contributed from the former. DOM is mainly consisted of microbial products based on proxies f470/520 and BIX, indicating that DOM in water is apparently affected by microbial degradation.

[Spectral Characteristic of Dissolved Organic Matter in Xiaohe River, Hebei].

The spectral characteristic of dissolved organic matter (DOM) in Xiaohe River, Hebei, was investigated by fluorescence spectroscopy, ultraviolet-visible absorption spectroscopy, and basic chemical water quality indicators. The data was then statistical analyzed using principal component analysis and correlation analysis method. The result based on 3D excitation-emission matrix fluorescence spectroscopy showed that DOM in Xiaohe River contained both protein-like and humus-like components.