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To explore the possible impact of river sediments on the endogenous pollution of water body under different dredging conditions, sediments in the Luling and Guanzui sections of Tuo River were selected as research object. On the basis of pollution assessment of typical heavy metals (i.e. Cd, Cr, Cu, Ni, Pb, Zn), the release characteristics of chemical oxygen demand (CODCr), total phosphorus (TP) and fluoride (F) in these two sediments were studied using an indoor disturbance test device. Results show that sediments of the Luling and Guanzui sections were unpolluted to moderately polluted by Cd and Cu. The comprehensive ecological risk of the selected heavy metals in the Luling and Guanzui sediments was low. However, the single potential ecological risk of Cd was at moderate risk level. Pollution level of heavy metals in Guanzui sediment is higher than that in Luling sediment. Owing to the influences of mineral composition, content of pollutants and chemical species of pollutants in sediments, CODCr, TP and F in the sediments of the two sections show different release characteristics. The Guanzui and Luling sediments showed release 'source' characteristics for CODCr and F, respectively, to overlying water. CODCr and F were the priority pollutants of endogenous pollution in the Guanzui and Luling sections, respectively, of Tuo River. [ABSTRACT FROM AUTHOR]

To study the pollution characteristics and sources of heavy metals in the soil near an urbanrural junction in an industrial area, this research analyzes the soil in the urban-rural junction of an industrial zone in Xigu District, Lanzhou City, Gansu Province. An X-ray fluorescence spectrometer is used to determine the content of 11 elements, namely, Cr, Mn, Co, Ni, Cu, Zn, As, Cd, Hg, Pb, and Fe, in the soil. Pollution evaluation is carried out using geo-accumulation, single-factor pollution, and Nemerow comprehensive pollution indices. The sources of heavy metals are analyzed through correlation analysis, factor analysis, cluster analysis, and other mathematical statistical methods, combined with spatial distribution characteristics. Results show that in the soil of the study area, only the average contents of Co, Zn, Hg, and Pb elements exceed the elemental background value of Gansu soil. The contents of other heavy metals do not exceed the elemental background value of Gansu soil. Mn, Fe, Co, Cr, As, and Ni are mainly affected by natural sources (earth-forming parent material or geological background). Pb, Cu, and Zn are mainly affected by anthropogenic sources (such as human agricultural activities). Cd and Hg are mainly from industrial sources (industrial activities, such as those from the petrochemical industry). The research results can provide a reference for the prevention and control of heavy metal pollution in the study area. [ABSTRACT FROM AUTHOR]

The deteriorating water quality seriously affects human health and social development, accurate identification and quantification of pollutant sources is an important scientific prerequisite for water pollution prevention and remediation. Based on the extensive literature analysis, the basic principles, development history and application characteristics of three major receptor models for water pollution source analysis are summarized, and their similarities and differences in the application of single and combined forms for source analysis of different pollution parameters in various water types (including atmospheric precipitation, river water, lake, reservoir, and groundwater) are analyzed. The results show that the three receptor models have their own advantages and limitations, and where the source discharge inventory is unknown, it is necessary to compare and discuss the apportionment results of multiple models to reduce the uncertainty of the data in order to obtain scientifically valid conclusions. Moreover, the development of hybrid/integrated models should be an important direction for future source apportionment research of water environment. [ABSTRACT FROM AUTHOR]

Shallow groundwater is essential for irrigation in Huaibei Plain, China, as the area is one of the most important grain bases. Therefore, 22 shallow groundwater samples were collected in the area, and their major ion concentrations and suitability for irrigation were evaluated using various indices (sodium adsorption ratio, Kelly's ratio, sodium percent, residual sodium carbonate, magnesium hazard, and permeability index). Moreover, Piper diagram, Gibbs diagram, ion ratio and principal component analysis (PCA) were applied in hydrochemical elucidation. The results indicated that the most of the water samples were unsuitable for irrigation because of high Na+, Mg2+, and HCO3- contents. The major hydrochemical type of shallow groundwater was NaMg-HCO3. The ion composition of groundwater was controlled by water-rock interaction, with dominantly controlled by silicate weathering and followed by carbonate dissolution. Na+ mainly weathered from the silicate weathering, and a few were derived from halite dissolution and ion exchange reaction. :Mg2+ also mainly weathered from silicate weathering. HCO3- mainly originated from the reaction of dissolved CO2 in water with silicate. According to the PCA results, the hydrochemistry of 2/3 samples were controlled by natural processes and 1/3 of them have been influenced by human activities. [ABSTRACT FROM AUTHOR]

Sunan mining area was selected as investigated area from Huaibei coalfield to study the accumulation and enrichment characteristics of heavy metals in soil and plant. This study focused on heavy metal content characteristics about surface and profile soil, maize plant bioconcentration transfer characteristics and health risk assessment of heavy metals. The results indicated that the mean content of heavy metals (Cd, Cr, Pb, Ni, Zn and Cu) were 0.26, 52.69, 24.09, 29.77, 57.00 and 26.09mg/kg in surface soil, respectively. Cr exceeded the secondary standard of national environment quality standard for soil in China with the proportion of 50%, while other heavy metals did not exceed the corresponding standard. Single factor pollution index showed that 8.33% of Ni and Cd samples belonged to the warning limit pollution level respectively, and other heavy metals were at clear. Profile heavy metal vertical migration characteristics revealed that except for Pb, other heavy metals showed an obvious trend of vertical migration in different degrees. Among organs of maize plant (e.g. roots, stems, leaves), Zn content was highest, while Cd content was lowest. The bioconcentration factor( BCF) and transfer factor (TF)of Cd were relatively larger, and maize plant root tended to absorb more Cd from the soil firstly, and then transferred to the upper part of the ground. Health risk assessment results suggested that the health risk of six heavy metals to children was much higher than that of adults, and Cr contribution were the largest among them. [ABSTRACT FROM AUTHOR]

To evaluate the quality and identify the priority pollutants of heavy metals (HMs) in soil from Linhuan mining district, northern Anhui Province, a total of 14 representative surface soil samples were collected, and eight HMs (Fe, Mn, Cd, Cr, Pb, Ni, Zn and Cu) were determined. Nemerow synthetic pollution index and Hakanson potential ecological risk index were performed to assess the pollution statues of HMs. Furthermore, multivariate statistical analysis (e.g., Pearson correlation, cluster analysis, and principal components analysis) were applied to examine the possible sources of HMs. Results showed that, with the exclusion of Cd, the concentrations of the other seven HMs did not exceed the secondary standard values of National Environment Quality Standard for Soil. The values of single pollution index and Nemerow synthetic index both indicated that HMs pollution level was Cd>Ni>Zn, Cu>Cr>Pb, and Cd, Ni and Pn were at clean to alarm limit level. However, the values of ecological risk index further revealed that Cd was at moderate to considerable level, while the other HMs and synthetic index belonged to low level. Multivariate statistical analysis suggested that Cu and Mn were mainly originated from coal mining activities, while the other HMs was affected by other anthropogenic sources (e.g., agricultural, traffic and industrial activities). These results will be significant for understanding the pollution level of HMs in the soil from Linhuan mining district, as well as for the local environmental protection and risk management. [ABSTRACT FROM AUTHOR]