Environmental Quality Standards Of China Research Articles

Multivariate-statistical assessment of heavy metals for agricultural soils in northern China.

The study evaluated eight heavy metals content and soil pollution from agricultural soils in northern China. Multivariate and geostatistical analysis approaches were used to determine the anthropogenic and natural contribution of soil heavy metal concentrations. Single pollution index and integrated pollution index could be used to evaluate soil heavy metal risk. The results show that the first factor explains 27.3% of the eight soil heavy metals with strong positive loadings on Cu, Zn, and Cd, which indicates that Cu, Zn, and Cd are associated with and controlled by anthropic activities. The average value of heavy metal is lower than the second grade standard values of soil environmental quality standards in China. Single pollution index is lower than 1, and the Nemerow integrated pollution index is 0.305, which means that study area has not been polluted. The semivariograms of soil heavy metal single pollution index fitted spherical and exponential models. The variable ratio of single pollution index showed moderately spatial dependence. Heavy metal contents showed relative safety in the study area.

Hydrochemical evaluation of surface water quality and pollution source apportionment in the Luan River basin, China

In the context of rapid economic growth in China, hydrochemical characteristics of stream water quality are being influenced by a variety of natural and anthropogenic inputs. We determined 10 hydrochemical parameters of the surface water at 29 monitoring sites in the Luan River basin of northern China during 2007-2009. Water quality hydrochemistry was evaluated using fuzzy comprehensive analysis based on the National Surface Water Environmental Quality Standards of China. Our results showed that 14 sites were classified as 'meeting standard (MS)' while the other 15 sites were classified 'non-meeting standard (NS)'. According to principal component analysis, four potential pollution sources were identified that explained 80.6% of the total variance among these MS sites, and three potential pollution sources that explained 78.3% of the total variance among these NS sites. Furthermore, multi-linear regression of the absolute principal component scores was used to estimate contributions from identified pollution sources. Most water pollution variables were influenced primarily by municipal sewage and non-point pollution in MS sites. In NS sites, chemical industry wastewater pollution dominated. Pollution in the main stream was more serious than that in the small tributaries. Our findings provide useful information for developing better pollution control strategies for the Luan River.

Lead (II) ion detection in surface water with pM sensitivity using aza-crown-ether-modifiedsilver nanoparticles via dynamic light scattering

In this paper, we reported ultrasensitive lead ion detection in environmental water with pMsensitivity using aza-crown-ether-modified silver nanoparticles (ACE-Ag NPs) through dynamiclight scattering (DLS). The colorimetric method based on ACE-Ag NPs is not capable of detectingPb2 + ions over othermetal ions (Fe3 + , Co2 + ,Cu2 + ,Hg2 + ,Cd2 + ,Ag + ,Li + ,Na + ,K + andCs + ) with high sensitivity. But DLS has improved the selectivity and sensitivity of thePb2 + detectionsystem (50-fold or more) over colorimetric method, and its detection limit is 0.25 pM (1.03 ppt). ThePb2 + DLS assay can beapplied to detect Pb2 + in the environmental water, such as in Yangtze and East Lake water samples with a detectionlimit of 0.20 and 0.22 pM, which is much lower than the maximum contamination level of4.8 × 10 − 8 M for lead in surface water defined by the national environmental quality standards ofChina (GB 3838-2002). Also, this method has a good performance in the determination ofPb2 + in drinking water, which is much lower than the maximum contamination level (MCL) of72 nM for lead as defined by the US Environmental Protection Agency (EPA).

Accumulation and bioavailability of copper and nickel in wheat plants grown in contaminated soils from the oasis, northwest China

This paper studied the accumulation and bioavailability of copper and nickel in wheat plants grown in contaminated soils from the oasis, northwest China. The concentrations of Cu and Ni in studied soils were all more than Cu and Ni limit of grade II soil environmental quality standards in China; furthermore the concentration of Cu in soil S5 and the concentrations of Ni in soil S1, S3, S5, and S6 exceeded grade III soil environmental quality standards in China. Among eight extractants, the extractable Cu concentrations in soils generally followed the descending order EDTA > Citric acid > NH 4Ac > NH 4NO 3 > MgCl 2 ≈ Tartaric acid > Acetic acid > Oxalic acid. The extraction capacity of Ni was as follow: Citric acid > EDTA > NH 4Ac > tartaric acid > NH 4NO 3 ≈ Acetic acid ≈ Oxalic acid > MgCl 2. The sequences of Ni average concentrations in different parts of the wheat plant were roots > leaves > shells > stocks > grains; the sequences of Cu average concentrations in different parts were also roots > leaves > shells > grains > stocks. Soil studied is not fit to plant the wheat crops for human consumption; soils studied posed high potential health risk for human health through food chains. Average Bio-concentration factor (BCF) and translocation factor (TF) of Cu in different parts of wheat plants were greater than those of Ni. The process of Cu and Ni uptake and accumulation by wheat plants were probably linked to the concentrations of available copper and nickel in the oasis soils, physical and chemical parameters of soils, and different parts of wheat plants. Citric acid and NH 4Ac extraction procedures provided a good indication of Cu bioavailability among nine kinds of evaluation methods.

Soil Microbial Characteristics Under Long-Term Heavy Metal Stress: A Case Study in Zhangshi Wastewater Irrigation Area, Shenyang

Soil samples were collected from Zhangshi Wastewater Irrigation Area in the suburb of Shenyang City, China, an area with a 30-year irrigation history with heavy metal-containing Wastewater. The chemical properties and microbial characteristics of the soils were examined to evaluate the present situation of heavy metal pollution and to assess the soil microbial characteristics under long-term heavy metal stress. In light of the National Environmental Quality Standards of China, the soil in the test area was heavily polluted by Cd and to a lesser degree by Zn and Cu, even though Wastewater irrigation ceased in 1993. Soil metabolic quotient ( qCO 2) had a significant positive correlation, while soil microbial quotient ( q M) had a negative correlation with content of soil heavy metals. Soil microbial biomass carbon (MBC) had significantly negative correlation with Cd, but soil substrate-induced respiration (SIR), dehydrogenase activity (DHA), cellulase activity, and culturable microbial populations had no persistent correlations with soil heavy metal content. Soil nutrients, except for phosphorous, showed positive effects on soil microbial characteristics, which to a certain degree obscured the adverse effects of soil heavy metals. Soil Cd contributed more to the soil microbial characteristics, but q M and qCO 2 were more sensitive and showed persistent responses to heavy metals stress. It could be concluded that q M and qCO 2 can be used as bioindicators of heavy metal pollution in soils.

Assessment and prediction of overall environmental quality of Zhuzhou City, Hunan Province, China

Fuzzy comprehensive assessment was applied to assess the quality of air, water and soil in Zhuzhou City, Hunan Province, China based on the monitoring data of 1997 and National Environmental Quality Standards of China. Results show that Zhuzhou air quality belonged to Class II with industry and traffic as the main control areas and SO 2 as the major pollutant. Water quality within the Zhuzhou section of the Xiang River belonged to Class IV, with the Xiawan section as the main control area and NH 3-N as the major pollutant. Soil environmental quality with respect to heavy metal pollution belonged to Class III, with Cd as the major pollutant. For those pollutants showing significant differences between the years of 1990–1997, predictions were made for the environmental quality for the period 1998–2003. According to the assessment results, cleaner production in the key pollution sources and the establishment of a municipal sewage treatment plant are proposed to improve the environmental quality of Zhuzhou City.