Determination of major and trace elements in plant samples by inductively coupled plasma optical emission spectrometry with deep eutectic solvent extraction based on choline chloride and carboxylic acids.

A rapid, precise, and environmentally friendly approach utilizing an ultrasound assisted deep eutectic solvent-based extraction method was developed for the extraction of Ca, Fe, K, Mg, Mn, Na, P, S and Zn from plant samples. The investigation was conducted on deep eutectic solvents that are based on choline chloride and carboxylic acids. The determination of target analytes in the extracts was carried out using inductively coupled plasma-optical emission spectrometry (ICP-OES). The DESs based on malic acid were found to exhibit the highest extraction recovery values (95-106%). The parameters affecting the extraction of target analytes were optimized using standard reference materials. The target analytes can be effectively extracted from plant samples using 0.5 g of DESs and ultrasonication for 40 minutes. The determination results of the reference samples indicated that the relative error (RE) was below 15.1%, and the relative standard deviation (RSD) was less than 6.3%, demonstrating excellent accuracy and precision. The proposed method was employed to quantify target analytes in actual plant samples. The accuracy of this method was not significantly different from that of the microwave digestion method. The proposed method has been demonstrated to be a valid approach for the determination of target elements in actual plant samples.

Estimating metal loading into the sea from tidal rivers using total suspended solids and water quality models.

Metals are mainly transported with suspended sediments in tidal rivers, and it is difficult to describe the transformation process of metals. Freely dissolved metals and suspended metals (including acid-soluble, reducible, oxidizable, and residual metals) were separately analyzed according to a sequential extraction scheme. The regression of the observed suspended metals and total suspended solids (TSS) concentrations allowed us to couple the two pollutant types. TSS is a highly dynamic parameter, and a model can be developed to simulate TSS transport. Thus, a method including the following five steps was proposed to estimate the loadings of metals entering the sea using TSS concentrations and water quality models: (1) collecting and observing basic information on the hydrological conditions, pollution sources, and water quality of the studied river; (2) obtaining a regression model between the suspended metals and TSS and analyzing the potential of establishing a suspended metal flux model; (3) introducing a model describing the fluxes of water-soluble metals into the sea; (4) establishing a calculation model to determine the fluxes of suspended metals into the sea; and (5) characterizing the fluxes of metals into the sea. The method was programmed, and metal concentrations and fluxes could be characterized quickly when the basic river data were sufficient. In addition, if regional development scenarios could be set, metal loadings in all scenarios could be predicted through the procedure developed herein, and some effective suggestions on regional sustainable development might be proposed for decision makers. Integr Environ Assess Manag 2022;18:198-208. © 2021 SETAC.

Related norms of the ENGOs, one vital role in environmental improvement needed to be enhanced in China.

Four behavior subjects, including governments, enterprises, and public and environmental non-government organizations (abbreviated as ENGOs), all play vital roles in environmental protection. As an important component, the ENGOs of all the world focus on environmental improvement and provide services for the whole society. In developed countries, the ENGOs have been formed earlier, and all kinds of regulation, supervision, and maintenance systems on the organizations are relatively mature. The development of the ENGOs in China started late, but the development speed was very fast. Some issues, including the exploring on their existing situation and how to promote their role in environmental protection, should be concerned. In total, 2510 ENGOs' information in China was collected and analyzed in the study. The ENGOs in the nation were not uniformly distributed, and there were great differences in the number of the ENGOs among the 34 provinces of China. With a few exceptions, the ENGOs in China were generally small in the scale and poor in the viability. They were mostly research-oriented and often less participating. The organizations' development and improvement still needed a long-term arduous course. Many negative factors might influence the sustainable and healthy development of the ENGOs in China, and the legislation might be one cause. Several aspects-related norms, including the registration system, the financial support mechanism, and the identification on their plaintiff qualification, needed to be improved to encourage the development of these organizations and then promote the improvement of environmental quality better in China.

Observations on the particle pollution of the cities in China in the Coronavirus 2019 closure: Characteristics and lessons for environmental management.

Particulate matter in the air seriously affects human health and has been a hot topic of discussion. Because of the coronavirus disease 2019 (COVID-19) lockdown in cities in China, sources of particulate matter, including gasoline-burning vehicles, dust-producing building sites, and coal-fired factories, almost all ceased at the end of January 2020. It was not until early April that outdoor activities recovered. Ten cities were selected as observation sites during the period from 19 December 2019 to 30 April 2020, covering the periods of preclosure, closure, and gradual resumption. A total of 11 720 groups of data were obtained, and 4 indicators were used to assess the characteristics of the particle pollution in the period. The quality of the atmospheric environment was visibly influenced by human activities in those 5 mo. The concentrations of particulate matter with particle sizes below 10 µm (PM10) decreased slightly in February and March and then began to increase slowly after April with the gradual recovery of production. The concentrations of particulate matter with particle sizes below 2.5 µm (PM2.5) decreased greatly in most regions, especially in northern cities, during closure and maintained a relatively stable level in the following 3 mo. The trends of PM10 and PM2.5 indicated that the reduced human activities during the COVID-19 lockdown decreased the concentrations of particulate matter in the air, and the difference between the PM10 and PM2.5 trends might be due to the different sources of the 2 particles and their different aerodynamics. However, during closure, the particulate matter pollution in the cities remained at a high level, which indicated that some ignored factors other than outdoor production activities, automobile exhaust, and construction site dust might have contributed greatly to the PM10 and PM2.5 concentrations, and the tracing of the particulate matter should be given further attention in environmental management. Integr Environ Assess Manag 2021;17:1014-1024. © 2021 SETAC.