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Copyright of Journal of Agro-Environment Science is the property of Journal of Agro-Environment Science Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Industrial Minerals & Processing / Huagong Kuangwu yu Jiagong is the property of Industrial Minerals & Processing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the case study of the pollution control over the heap leaching cyanide residue left by historical gold mines in arid areas of western China. Based on a thorough analysis of climate, hydrogeology, and the characteristics of heap leaching cyanide residue pollutants, in-situ closure operation is employed to verify the pollution control effect over the pollutant such as heavy metals in heap leaching cyanide residue. The paper in detail describes the in-situ sealing and isolation scheme, control and monitoring scheme, and auxiliary schemes. After implementation, the environmental pollution risks are effectively controlled, and the peripheral environment is evidently improved, achieving anticipated engineering goals. The control technology can provide references for the pollution control of heap leaching cyanide residue generated from similar gold mines. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Pesticide Science / Nongyaoxue Xuebao is the property of Chinese Journal of Pesticide Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Heavy metals in tailings leachate are an important source of environmental pollution in tailings ponds, and rainfall and the soaked time in rainwater are the key factors affecting the leaching of heavy metals. Based on this, this paper discusses the leaching law of heavy metals in tailings under different liquid solid ratios. Two experimental methods, static leaching and dynamic leaching, were used to simulate the tailings with different particle sizes, and the change of leaching concentration of heavy metals (Cu, Mn, Zn) in tailings samples were analyzed. The results show that: under the simulated conditions of pH = 5. 4, the leaching concentration of heavy metals in static leaching decreases with the increase of liquid solid ratio. The leaching degree of heavy metals in tailings with different particle sizes is: fine particle size is better than medium particle size, and coarse particle leaching is minimal. The effects of liquid solid ratio on leaching concentrations of different heavy metals is as follows: manganese>copper>zinc. Under dynamic leaching, the leaching concentration of heavy metals shows an obvious downward trend with the increase of leaching amount, and there are two stages of rapid decline and slow decline. The fitting of the mathematical model of heavy metal release showed that the release of heavy metals was a complex process, and the release kinetics of Cu and Zn fitted well with the double constant rate equation; the release process of manganese was better described by the modified Elovich equation. [ABSTRACT FROM AUTHOR]

Copyright of Nonferrous Metals (Mining Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Objective] The present paper aimed to provide the scientific basis for rational land-use planning, soil resources conservation and pollution-free agricultural development in Luodian County, Guizhou. [Method] The effects of five typical land-use patterns (forestland, natural grassland, artificial grassland, cropland and abandoned farmland) on content and environment contamination of Cd, Cr, Pb, Ni, Hg and As in topsoil were evaluated by Nemerow comprehensive index, single-factor contamination index and Hakanson potential ecological hazard methods. [Result] The content of 6 heavy metals in topsoil was Cr > Pb > Ni > As > Cd > Hg and lower than the contamination background value of heavy metals in Guizhou overall. The topsoil Cd content was the highest in abandoned farmland and lowest in forestland. The topsoil Cr content was the highest in abandoned farmland and lowest in natural grassland. The topsoil Pb and Hg content was the highest in cropland and lowest in forestland. The topsoil Ni content was the highest in artificial grassland and lowest in natural grassland. The topsoil As content was the highest in natural grassland and lowest in cropland. The topsoil Cd, C.r, Pb and Hg content was high relatively and greatly influenced by human activity. Topsoil Cr had the same source as Ni, Hg and As. The topsoil As content was closely related to soil pH. The topsoil Cd and Cr content was closely related to soil cation exchange capacity (CEC) . The topsoil Pb, Hg and As content was closely related to soil organic matter (SOM). [Conclusion] Six heavy metals in topsoil do not cause soil contamination. The single-factor contamination index and potential ecological hazard index both are at the clean level. The pollution-free agriculture can be vigorously developed according to local soil nutrient, soil fertility and land-use pattern in Luodian County, Guizhou. [ABSTRACT FROM AUTHOR]

With the continuous development of industry, environment pollution such as soil acidification and heavy metal pollution of soil becomes increasingly serious, especially in the acidic soil region of southern China. Liming is a traditional and effective method to improve acidic soil. Manual spreading is a kind of traditional method of liming, but it is inefficient and has some side effects like skin damage of workers because of the corrosive property of lime. In order to solve the deficiencies of manual liming and compensate the technology gap of liming machine between domestic and overseas market, we designed a lime spreading machine which was able to be assembled with other agricultural machinery to become combined machine. The development of liming machine has great significance to improve liming efficiency and working conditions. This paper discussed the structure and working principle of the pros spiral lime spreading machine. The machine used the spread roller which was similar to the structure of pros spiral as working parts, used the overlapped waist-shaped hole as the lime spreading outlet, and controlled the waist-shaped hole overlapping area through adjusting assembly to adjust the lime spreading amount. Through experiment we determined the lime outlet size and the lime spreading roller's rotation speed of the lime spreading machine, and experiment results showed that: Firstly, when the lime spreading roller speed was below 125 turn per minute, for the same waist-shaped lime spreading outlet, the lime spreading amount per turn of lime spreading roller could be treated as a constant value, i.e. the spreading amount and lime spread roller's rotation speed were in a linear relationship; Secondly, when the number of lime spreading plate was 40, the hole was waist-shaped hole with the size of 25 mm*10 mm and the rotation speed of the roller was in 120 turn per minute, we got the lime spreading amount of 1 500 kg/h which met the maximum requirements of lime spreading. Considering the linear relationship between the lime spreading amount and the number of lime spreading hole, and the complex conditions after assembled with rotary cultivator, we increased the number of the waist-shaped hole and decreased the rotation speed of lime spreading roller meanwhile kept the lime spreading speed unchanged, and at last determined the lime spreading hole number to be 60 and the roller's rotation speed to be 80 turn per minute as the optimal scheme. We also analyzed the power consumption condition of the lime spreading process and calculated the total power consumption of the working process. Finally, the field test of the lime spreader was carried out, which was conducted in the dry paddy field. Field test results showed that, under the conditions of the lime spreading cultivator at a speed of 5 km per hour, the lime spreading roller at a speed of 80 turn per minute and the overlapping area of the lime spreading hole at maximum size, when the adjusting bar of adjusting mechanism was located in Location XIII, the lime spreading amount reached 1 566.7 kg per hectare. When the adjusting bar of adjusting mechanism were located in Location XII, X and VII, respectively, the lime spreading amounts met the demands of annual lime spreading amount for the first, second and third year, respectively; and when the adjusting bar was at Location II, lime spreading machine almost closed all the lime spreading holes. [ABSTRACT FROM AUTHOR]

Thermophilic aerobic fermentation (composting) is an important biotechnology for the treatment and resource utilization of various organic solid wastes. However,conventional composting restricts a wide application due to its low fermentation temperature ranging from 50°C to 70°C,long composting period and unsatisfying compost quality. Recently,an innovating technology of hyperthermophilic composting (also known as hyperthermophilic aerobic fermentation) has been developed and confirmed to overcome the shortcomings of conventional composting in engineering practice. Compared to conventional composting,it can run at high temperatures over 80°C for 5 to 7 days by the inoculation of hyperthermophilic bacteria,which results in the advantages of accelerated humification and effective pollution control. This paper aims to review the recent research progress on the development process,key technical characteristics,and the accelerated humification and pollution control mechanisms of hyperthermophilic composting,including the emission reduction of N2O,the removal of antibiotic resistance genes,the biodegradation of microplastics,and the passivation of heavy metals. This review will provide theoretical and practical guidance for treating and utilizing organic solid wastes by hyperthermophilic composting. [ABSTRACT FROM AUTHOR]

Copyright of Research of Environmental Sciences is the property of Research of Environmental Sciences Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to understand the heavy metal pollution in surrounding farmland tillage soil caused by coal mine, this paper studied the area around a coal mine in southwest Shandong province. The 104 samples of surrounding farmland tillage soil were collected, and the concentration of heavy metals including Cr, Ni, Cu, Cd, Zn, Pb were tested by ICP-MS. Single factor index, nemero index and geoaccumulation index were used to analyze the spatial distribution characteristics and the appraise pollution level of six heavy metals. The results show that the six kinds of heavy metals are obviously accumulated, and have different spatial distribution characteristics in the nearby regions of coal gangue dump, industrial square, coal transfer station and transit lines. Only Cu and Ni elements have significant correlation in spatial distribution. The total pollution is in a light degree. It has no Cr element pollution, small-scale slight pollution area of Ni element, some slight pollution area and small-scale moderately pollution area of Cd element in the research area. Other elements including Cu, Zn and Pb are relatively safe. [ABSTRACT FROM AUTHOR]

Copyright of Transactions of the Chinese Society of Agricultural Engineering is the property of Chinese Society of Agricultural Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)