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The total concentrations of 12 heavy metals in surface soils (SS, 0-20 cm), middle soils (MS, 30-50 cm) and deep soils (DS, 60-80 cm) from an acid-leaching area, a deserted paddy field and a deserted area of Guiyu were measured. The results showed that the acid-leaching area was heavily contaminated with heavy metals, especially in SS. The mean concentrations of Ni, Cu, Zn, Cd, Sn, Sb and Pb in SS from the acid-leaching area were 278.4, 684.1, 572.8, 1.36, 3,472, 1,706 and 222.8 mg/kg, respectively. Heavy metal pollution in the deserted paddy field was mainly concentrated in SS and MS. The average values of Sb in SS and MS from the deserted paddy field were 16.3 and 20.2 mg/kg, respectively. However, heavy metal contamination of the deserted area was principally found in the DS. Extremely high concentrations of heavy metals were also observed at some special research sites, further confirming that the level of heavy metal pollution was very serious. The geoaccumulation index (I) values revealed that the acid-leaching area was severely polluted with heavy metals in the order of Sb > Sn > Cu > Cd > Ni > Zn > Pb, while deserted paddy field was contaminated predominately by metals in the order of Sb > Sn > Cu. It was obvious that the concentrations of some uncommon contaminants, such as Sb and Sn, were higher than principal contaminants, such as Ni, Cu, Zn and Pb, suggesting that particular attention should be directed to Sn and Sb contamination in the future research of heavy metals in soils from e-waste-processing areas. Correlation analysis suggested that Li and Be in soils from the acid-leaching area and its surrounding environment might have originated from other industrial activities and from batteries, whereas Ni, Cu, Zn, Cd, Pb, Sn and Sb contamination was most likely caused by uncontrolled electronic waste (e-waste) processing. These results indicate the significant need for optimisation of e-waste-dismantling technologies and remediation of polluted soil environment. [ABSTRACT FROM AUTHOR]

Carbon isotope reversal becomes a typical characteristic of shale gases in some North America shale gas play. The carbon isotope reversal is divided as two types: partial reversal with δ13Cmethane >δ13Cethane <δ13Cpropane, and wholly reversal with δ13 Cmethane >δ13Cethane >δ13 Cpropane There are three possible mechanisms for the carbon isotope reversal: ① mixture of kerogen-cracking gas and oil-cracking gas in shale; ② reaction of residual organic matter in shale with metal and/or water; and ① carbon isotope fractionation of nature gas caused by diffusion and adsorption/desorption. The carbon isotope reversal is usually related to over pressure in a shale reservoir and a high gas yield, therefore, it can be used to identify core areas for a shale gas play. [ABSTRACT FROM AUTHOR]

The Lower Paleozoic shales in China south area, which maturities are obviously higher than those of the shales in the producing gas field in the United State, have not been researched on the questions of its gas content. In this study, the maturities of those shales were accurately evaluated through spectral analysis of Raman reflectance, the dead line of gas generation, the evolution of the porosity and nanopore of shales with maturity, as well as the gas content of organic-rich shales with very high maturities were further investigated. The results indicate that the maturities of the Lower Paleozoic shales in China south area Ro rang from 2.0% to 5.0%, and most of them are higher than the dead line of gas generation Ro = 3.1% ; both of the specific surface area and nanopore volume of organic-rich shales increases with maturity, which allowing them to keep certain porosities even in very high maturities (Ro = 3.5% - 4.0%). Although being in very high maturity, the Lower Paleozoic shales in China south area still have huge shale gas potential. [ABSTRACT FROM AUTHOR]

In North American, a lot of work had been done on shale gas formation, storage, enrichment, evaluation and core area prediction for gas shale strata with relative simple structure deformations, middle-high maturities (Ro < 3.0%) and shallower burial depths (<4 000 m), great achievements have been made, and industrial scale shale gas exploitation have been carried out. The lower Paleozoic strata in China south area are characterized by excessively high thermal maturities (Ro = 2.5 % -4.0%), strong structure reforming, and great variations of their current burial depths. For the shale gas evaluation of this set of strata, there is lack of available theories and methods. In order to elude exploration risk and obtain benefit, the fundamental researches pointing to these characters should be conducted based on achievements made by North American, mainly including techniques of in situ measurements of gas content in shales and quantitative assessment system of OGIP (original gas in place), evaluation of shale gas potentials of the demonstrated areas or blocks, and determination of the main factors controlling shale gas resources. The purpose of these studies is to provide theoretical guides and technical methods for the high efficient exploitation of shale gas in the Lower Paleozoic strata of China South area. [ABSTRACT FROM AUTHOR]

Through UV/H 2 O 2 photocatalytic advanced oxidation technique the performance, kinetics, pathway, and mechanism of ortho-dichlorobenzene (O-DCB) in water and the effect parameters of degradating reaction were studied systematically. The results showed that the reaction of photocatalytic degradation of O-DCB was fast and accorded well with the pseudo-first-order kinetics. The roles of some parameters, such as the pH, the initial concentrations of O-DCB, H 2 O 2 , and some anions in reaction solution, were examined in detail. It was found that weak acidic or neutral environment was favorable to the degradation reaction and some anions slowed down the photocatalytic degradation rate. Input amount of H 2 O 2 possessed the best value under specified condition. The intermediates of O-DCB degradation were also tentatively identified 2,3-dichlorophenol, 3,4-dichlorophenol, formic acid, acetic acid, and oxalic acid mainly adopting GC/MS and ion chromatogram (IC) techniques. According to this, the pathway and mechanism of UV/H 2 O 2 photocatalytic degradation of O-DCB were deduced and led. [ABSTRACT FROM AUTHOR]

In this study, advanced technologies were applied to investigate the geochemistry, mineral compositions, porosity and pore structures of the Permian shale core samples from this area. The results show that the Permian source rocks have an average porosity up to 5.37% and the nanoscale pores are mainly developed as micro- and meso-pores. The total organic carbon (TOC) content and clay mineral content of the shales are key factors to control gas adsorption capacities and pores sizes. The well developed nanopores and large surface area in the Permian organic-rich shale could provide good conditions for shale gas storage. [ABSTRACT FROM AUTHOR]