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991.
Chaulya S. K. Chakraborty M. K. Ahmad M. Singh R. S. Bondyopadhay C. Mondal G. C. Pal D. 《Water, air, and soil pollution》2002,140(1-4):21-55
All major mining activities, particularly opencast coal mining,directly or indirectly contribute to the problem of air pollution.Therefore, air quality assessment and prediction arerequired to prevent and minimize the air quality deteriorationdue to various opencast coal mining operations. Determination ofemission rates for these activities is the first and foremostconcern. In view of the above, this study was undertaken to determinate emission rates and to develop empericalformulae to calculate emission rates of various opencast coalmining activities.To achieve the objectives, seven coal mining sites were selectedto generate site-specific emission data by considering miningpractices, method of working, geographical location,accessibility and above all resourceavailability. The study covers various mining activities andlocations including drilling, overburden loading and unloading,coal loading and unloading, the coal handling plant, the exposedoverburden dump, the stock yard, the workshop, the exposed pit surface roadsand haul roads.Based on the study, a set of twelve emperical formulae have beendeveloped for calculation of suspended particulate matter (SPM)emission rates from various opencast coal mining activities. Theemission of gaseous pollutants (sulphur dioxide and nitrogenoxide) has been found negligible for various mining activities.Therefore, observation for gaseous pollutants has been consideredfor overall mine activities and empirical formulae have subsequently beendeveloped.The developed empirical formulae were calculatedby a field study at another coal mine. The measured andcalculated values of emission rate were compared for eachactivity. Average correlation between the measured andcalculated values for different activities was estimated to be 85.6–99.9%, which indicates fairly good accuracy.Validation of the study was also carried out by means of thefugitive dust model (FDM) using the calculated emissionrate data from the empirical formulae for each mining activity of amine, meteorological data and other details as input.The average accuracy between measured and predictedvalues of concentration of SPM at certain receptor locations wasfound to be 79%. A user-friendly emission software called`EmissCalc' was developed to calculate emission rate, whichcan be used as input for different air quality models. 相似文献
992.
Cadmium sorption and desorption behaviour of hydroxy-Alinterlayered montmorillonite (pillared) was compared with unpillared montmorillonite. Characteristic properties of themontmorillonite, whose interlayer cations were replaced byhydroxy-Al polymers, are its thermal stability up to ~500 °C and increased surface area of about 300 × 103 m2 kg-1. The cation exchange capacity was reduced by ~30% after interlayering withpositively charged hydroxy-Al polymers.Cadmium sorption data for the two montmorillonites fitted verywell (R2 = 0.98 to 0.99) to the Freundlich equation. Inthe concentration range (0.89–17.79 μM Cd L-1) used for the experiment, the unpillared montmorillonite sorbed moreCd than the pillared montmorillonite. Cadmium is possibly retained by electrostatic and chemisorption mechanisms by thepillared montmorillonite whereas electrostatic attraction ismainly responsible for Cd sorption by unpillared montmorillonite. After 5 extractions with 0.01 M NaNO3the amount of Cd desorbed varied between 30–47 and 34–59% for unpillared and pillared montmorillonites, respectively. At lower concentrations of initially sorbed Cd, the amount ofCd desorbed was nearly equal for the two samples. 相似文献
993.
Stéphane Mombo Yann Foucault Frédéric Deola Irène Gaillard Sylvaine Goix Muhammad Shahid Eva Schreck Antoine Pierart Camille Dumat 《Journal of Soils and Sediments》2016,16(4):1214-1224
Purpose
At the global scale, gardening activities are often performed in urban areas with a historical background of pollution. In this study, a participatory program was developed with citizens concerned by gardening activities near a 50-year-old regulated lead recycling company, with the aim of co-constructing the tools for the assessment and management of potential sanitary risks induced by historic pollution with persistent (eco) toxic metals: lead and cadmium.Materials and methods
Soils and vegetables (lettuce, leek, celery, carrot, chard, pumpkin, and celeriac) samples were collected from four kitchen gardens neighboring a 50-year-old secondary lead smelter. Both total and in vitro human bioaccessible metal concentrations in the cultivated plants were measured in relation to soil characteristics.Results and discussion
The results showed that the soils of these gardens were slightly contaminated by metals (Pb, 77 to 236 mg kg?1; and Cd, 0.5 to 1 mg kg?1) in comparison with the natural geologic background. However, significant pollution of vegetables can occur especially with lead (Pb up to 9.8 mg kg?1 in lettuce) and certainly as a result of direct foliar transfer. The washing of plants before consumption is therefore recommended in the context of atmospheric fallout of ultrafine particles enriched with metals.Conclusions
Metal bioaccessibility measure integrates the influence of metal type, plant type, and soil physico-chemical properties. Based on the results, it is proposed that human bioaccessible fraction of metals may also be currently taken into account as well as total metal quantities and bioaccumulation factors in risk assessment studies performed in gardens. Overall, this study has led to reflections and functional recommendations aimed at reducing human exposure and to finally developing sustainable gardening practices.994.
Mohammad Wahsha Mandana Nadimi-Goki Claudio Bini 《Journal of Soils and Sediments》2016,16(4):1300-1305
Purpose
The present paper concerns the distribution and mobility of heavy metals (Cu, Pb, Zn and Fe) in the soils of some abandoned mine sites in Italy and their transfer to wild flora.Materials and methods
Soils and plants were sampled from mixed sulphide mine dumps in different parts of Italy, and the concentrations of heavy metals were determined.Results and discussion
The phytoremediation ability of Salix species (Salix eleagnos, Salix purpurea and Salix caprea), Taraxacum officinale and P?lantago major for heavy metals and, in particular, zinc was estimated. The results showed that soils affected by mining activities presented total Zn, Cu, Pb and Fe concentrations above the internationally recommended permissible limits. A highly significant correlation occurred between metal concentrations in soils.Conclusions
The obtained results confirmed the environmental effects of mine waste; exploring wild flora ability to absorb metals, besides metal exploitation, proved a useful tool for planning possible remediation projects.995.
Feng-He Wang Bin Zhao Fan Zhang Jay Gao Hao-Tian Hao Shengtian Zhang 《Journal of Soils and Sediments》2016,16(2):371-381
Purpose
The main objectives of the study were to (1) develop a one-step facile procedure for synthesizing a new chemical amendment agent with three chelating groups for solidifying multiple heavy metals, called sixthio guanidine acid (SGA), using guanidine hydrochloride and carbon disulfide as raw reactants and (2) assess its biodegradability, solidification effectiveness, and leachability in remedying soils contaminated with multiple heavy metals of various concentrations compared with other traditional amendment agents.Materials and methods
Polluted soil samples were collected near a metalliferous mining site of Qixiashan in the southeast of Nanjing, China. Their concentrations were determined at 22.15–320 mg kg?1 for As, 3.30–29.31 mg kg?1 for Cd, 115.66–158.65 mg kg?1 for Ni, 165.04–1677.06 mg kg?1 for Pb, and 355.6–2426.91 mg kg?1 for Zn. Biodegradability of SGA was assessed in accordance with GB/T 21831-2008 and OECD-301D. Total concentration of heavy metals was determined according to ISO11466:1995. A modified three-step sequential Community Bureau of Reference (BCR) extraction procedure was used to examine speciation of heavy metals in the soil sample, and concentrations of heavy metals were measured by using inductively coupling plasma optical emission spectrometry (ICP-OES). Leachate extraction tests were carried out before and after the soil sample was solidified with different amendments in accordance with HJ/T 557-2009.Results and discussion
It is found that the optimal conditions for SGA synthesis are a molar ratio of 4:1, a reaction temperature of 40 °C, and a reaction time of 2 h. Under such conditions, SGA yield is achieved as high as 91.5 %. The bioavailability and mobility of As, Cd, Ni, Pb, and Zn in highly contaminated soils can be reduced via using SGA. Our results indicate that SGA is nonbiodegradative and much more effective than other traditional chemical amendment agents in that it is highly effective in comprehensively solidifying As, Cd, Ni, and Pb.Conclusions
SGA has the potential for comprehensive in situ remediation of soils contaminated with several heavy metal elements of various concentration levels, and such findings may be used as a guide to design new chemical amendment agents for rehabilitating soils contaminated with heavy metals.996.
Purpose
The validity of soil erosion data is often questioned because of the variation between replicates. This paper aims to evaluate the relevance of interreplicate variability to soil and soil organic carbon (SOC) erosion over prolonged rainfall.Materials and methods
Two silty loams were subjected to simulated rainfall of 30 mm h?1 for 360 min. The entire rainfall event was repeated ten times to enable statistical analysis of the variability of the runoff and soil erosion rates.Results and discussion
The results show that, as selective removal of depositional particles and crust formation progressively stabilized the soil surface, the interreplicate variability of runoff and soil erosion rates declined considerably over rainfall time. Yet, even after the maximum runoff and erosion rates were reached, the interreplicate variability still remained between 15 and 39 %, indicating the existence of significant inherent variability in soil erosion experiments.Conclusions
Great caution must be paid when applying soil and SOC erosion data after averaging from a small number of replicates. While not readily applicable to other soil types or rainfall conditions, the great interreplicate variability observed in this study suggests that a large number of replicates is highly recommended to ensure the validity of average values, especially when extrapolating them to assess soil and SOC erosion risk in the field.997.
Wenming Ma Zhongwu Li Keyi Ding Bin Huang Xiaodong Nie Yinmei Lu Haibin Xiao Guangming Zeng 《Journal of Soils and Sediments》2016,16(6):1705-1717
Purpose
This study aims to explore the dynamics of the factors influencing soil organic carbon (SOC) sequestration and stability at erosion and deposition sites.Materials and methods
Thermal properties and dissolved aromatic carbon concentration along with Al, Fe concentration and soil specific surface area (SSA) were studied to 1 meter depth at two contrasting sites.Results and discussion
Fe, Al concentrations and SSA size increased with depth and were negatively correlated with SOC concentration at the erosion site (P?<?0.05), while at the deposition site, these values decreased with increasing depth and were positively correlated with SOC concentration (P?<?0.05). TG mass loss showed that SOC components in the two contrasting sites were similar, but the soils in deposition site contained a larger proportion of labile organic carbon and smaller quantities of stable organic carbon compared to the erosion site. SOC stability increased with soil depth at the erosion site. However, it was slightly variable in the depositional zone. Changes in SUVA254 spectroscopy values indicated that aromatic moieties of DOC at the erosion site were more concentrated in the superficial soil layer (0–20 cm), but at the deposition site they changed little with depth and the SUVA254 values less than those at the erosion site.Conclusions
Though large amounts of SOC accumulated in the deposition site, SOC may be vulnerable to severe losses if environmental conditions become more favorable for mineralization in the future due to accretion of more labile carbon. Deep soil layers at the erosion site (>30 cm deep) had a large carbon sink potential.998.
Kangyi Lou Anushka Upamali Rajapaksha Yong Sik Ok Scott X. Chang 《Journal of Soils and Sediments》2016,16(8):2081-2089
Purpose
Remediate metal contamination is a fundamental step prior to reclaim oil sands tailing ponds, and copper (Cu(II)) is the most abundant metal in the tailings water or oil sands process-affected water (OSPW). Biochars produced at four pyrolysis conditions were evaluated for sorption of Cu(II) in synthetic OSPW to explore different biochar potentials in removing Cu(II) from the contaminated water.Materials and methods
Pine sawdust biochars pyrolyzed at 300 and 550 °C with and without steam activation were investigated by batch sorption experiments. Isotherm and kinetic studies were conducted to compare the sorption capacities of the four biochars and to examine potential mechanisms involved.Results and discussion
For all the biochars, Langmuir and pseudo-second order models were the best-fit for isotherm and kinetic studies, respectively. According to the Langmuir parameters, the maximum adsorption capacities of the biochars produced at 550 °C were around 2.5 mg Cu(II)?g?1, which were 30-folds higher than those produced at 300 °C. However, steam activation did not cause any significant difference in the biochars’ sorption performance. The kinetic study suggested that chemisorption involving valence forces was the limiting factor of the sorption. In addition, ion exchange and precipitation were likely the primary mechanisms for Cu(II) sorption which outweigh complexation with functional groups on the biochars’ surface.Conclusions
Pine sawdust biochar produced at 550 °C without steam activation could be utilized as a sustainable and cost-effective material to remove Cu(II) from the OSPW.999.
James F. Douglass Mark Radosevich Olli H. Tuovinen 《Journal of Soils and Sediments》2016,16(9):2263-2274
Purpose
The purpose of this study was to determine the first-order rate constants and half-lives of aerobic and anaerobic biomineralization of atrazine in soil samples from an agricultural farm site that had been previously used for mixing pesticide formulations and washing application equipment. Atrazine catabolic genes and atrazine-degrading bacteria in the soil samples were analyzed by molecular methods.Materials and methods
Biomineralization of atrazine was measured in soil samples with a [U-ring-14C]-atrazine biometer technique in soil samples. Enrichment cultures growing with atrazine were derived from soil samples and they were analyzed for bacterial diversity by constructing 16S rDNA clone libraries and sequencing. Bacterial isolates were also obtained and they were screened for atrazine catabolic genes.Results and discussion
The soils contained active atrazine-metabolizing microbial communities and both aerobic and anaerobic biomineralization of [U-ring-14C]-atrazine to 14CO2 was demonstrated. In contrast to aerobic incubations, anaerobic biometers displayed considerable differences in the kinetics of atrazine mineralization between duplicates. Sequence analysis of 16S rDNA clone libraries constructed from the enrichment cultures revealed a preponderance of Variovorax spp. (51 %) and Schlesneria (16 %). Analysis of 16S rRNA gene sequences from pure cultures (n?=?12) isolated from enrichment cultures yielded almost exclusively Arthrobacter spp. (83 %; 10/12 isolates). PCR screening of pure culture isolates for atrazine catabolic genes detected atzB, atzC, trzD, trzN, and possibly atzA. The presence of a complete metabolic pathway was not demonstrated by the amplification of catabolic genes among these isolates.Conclusions
The soils contained active atrazine-metabolizing microbial communities. The anaerobic biometer data showed variable response of atrazine biomineralization to external electron acceptor conditions. Partial pathways are inevitable in soil microbial communities, with metabolites linking into other catabolic and assimilative pathways of carbon and nitrogen. There was no evidence for the complete set of functional genes of the known pathways of atrazine biomineralization among the isolates.1000.
Bożena Dębska Jacek Długosz Anna Piotrowska-Długosz Magdalena Banach-Szott 《Journal of Soils and Sediments》2016,16(10):2335-2343