Red mud, the by-product of aluminum production, has been regarded as a problematic residue all over the world. Its storage involves risks as evidenced by the Ajka red mud spill,an accident in Hungary where the slurry ...Red mud, the by-product of aluminum production, has been regarded as a problematic residue all over the world. Its storage involves risks as evidenced by the Ajka red mud spill,an accident in Hungary where the slurry broke free, flooding the surrounding areas. As an immediate remediation measure more than 5 cm thick red mud layer was removed from the flooded soil surface. The removed red mud and soil mixture（RMSM） was transferred into the reservoirs for storage. In this paper the application of RMSM is evaluated in a field study aiming at re-utilizing waste, decreasing cost of waste disposal and providing a value-added product. The purpose was to investigate the applicability of RMSM as surface layer component of landfill cover systems. The field study was carried out in two steps： in lysimeters and in field plots. The RMSM was mixed at ratios ranging between 0 and 50% w/w with low quality subsoil（LQS） originally used as surface layer of an interim landfill cover. The characteristics of the LQS ＋ RMSM mixtures compared to the subsoil（LQS） and the RMSM were determined by physical–chemical, biological and ecotoxicological methods. The addition of RMSM to the subsoil（LQS） at up to 20% did not result any ecotoxic effect, but it increased the water holding capacity. In addition, the microbial substrate utilization became about triple of subsoil（LQS） after 10 months. According to our results the RMSM mixed into subsoil（LQS） at20% w/w dose may be applied as surface layer of landfill cover systems.展开更多
The mobility of Cu2+, Zn2+, Ni2+, and Cd2+ in soils treated with red mud was experimentally studied to explore the feasibility of remediation of smelter-contaminated soils. Red mud samples were collected with the Baye...The mobility of Cu2+, Zn2+, Ni2+, and Cd2+ in soils treated with red mud was experimentally studied to explore the feasibility of remediation of smelter-contaminated soils. Red mud samples were collected with the Bayer process (BRM) and confederate process (CRM) in the Aluminous Plant of Guizhou Province. Two farmed soil samples were collected from the Niujiaotang mining area, Guizhou Province, Southwest China. One sample was weakly polluted by fly ash; and the other was polluted severely by waste water from the smelter. For evaluating the potential of remediation, the concentrations of free metal ions and the distributions of metals in the soil were determined. The concentrations of free metal ions were measured by using the Donnan Membrane Technique, and the contributions of soil sorbents to the heavy metals adsorptions were calculated with Equilibrium Calculation of Speciation and Transport (ECOSAT). BRM reduced the concentrations of free metal ions in two kinds of soils, while CRM only favored the decrease of the concentrations of free metal ions in seriously contaminated soils. The experimental data also showed a tendency that the concentrations of free metal ions decreased proportionally with the amount of added red mud, which resulted from the increasing adsorption of heavy metal ions in the form of metal ion hydroxides.展开更多
A novel method to prepare soil nutrient amendment by calcining a mixture of white mud and potassium feldspar and its environmental assessment were investigated.Under the optimal conditions of a blending mass ratio of ...A novel method to prepare soil nutrient amendment by calcining a mixture of white mud and potassium feldspar and its environmental assessment were investigated.Under the optimal conditions of a blending mass ratio of 70-30 for white mud to potassium feldspar,a calcination temperature of 1 000℃,a calcination time of 1.5 h and spherulitic diameter of 2.0 cm,the calcined product,as a soil nutrient amendment,could be prepared with the following nutrient composition(mass fraction):K2O 4.16%,CaO 23.43%,MgO 5.04%,SiO2 22.92%,SO4 2-3.71%,and Cl -3.87%in 0.1 mol/L citric acid solution.The concentrations of heavy metals in the calcined product and the emission concentrations of harmful gases from a mixture of white mud and potassium feldspar during calcination process could qualify the National Standards without causing secondary environmental pollution.展开更多
The effects of sugar mill mud application on the availability of nutrients for plant uptake were investigated. Mill mud generated from conventional sugar mill operations was applied in three different rates and a leaf...The effects of sugar mill mud application on the availability of nutrients for plant uptake were investigated. Mill mud generated from conventional sugar mill operations was applied in three different rates and a leafy vegetable, locally called “PuiShak” or Indian spinach (Basellarubra L.) was grown for 60 days as a test crop in a pot culture experiment. Crop yield and essential nutrients like N, P, K and Zn uptake concentration was determined to come up with an inference that higher doses of mill mud application impose better effect on root and shoot uptake of these elements. A little infraction was observed for nitrogen uptake by plants for the maximum dose.展开更多
According to a lot of hydrological and environmental monitoring data, the condition of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is described. The occurrence and devel...According to a lot of hydrological and environmental monitoring data, the condition of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is described. The occurrence and development of soil and water loss is analyzed. The conclusion is that: (1) generally, the situation of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is light, however, soil and water loss in some regions is serious, especially in the middle reach area of the river; (2) soil and water loss in the Lancang River Mekong River (in Yunnan section, China) watershed presents developing tendency and it is mainly caused by human beings. In accordance with these results, the control measures for soil and water loss are discussed.展开更多
In order to preserve the environment, various treatment processes of wastewater discharges are used. Anaerobic digestion is part and allows among other things the production of sludge. The use of sewage sludge in semi...In order to preserve the environment, various treatment processes of wastewater discharges are used. Anaerobic digestion is part and allows among other things the production of sludge. The use of sewage sludge in semi arid, characterized by a binding climate, anthropozoogenic pressure and erosion, more increasingly important, is a solution for the restoration of degraded forest lands. In this study, the effect of an intake of composts from urban sewage sludge on soil quality has been studied in-situ soils degraded in semi arid area. The research followed in this work methodology is the first to evaluate the effectiveness of contribution of compost over time on the restoration of the physico-chemical quality of forest soils, then to evaluate the effectiveness of compost quality depending on the state of disturbance of the ecosystem to restore the chemical quality of these soils. Our results show a significant effect of sewage sludge on soil’s physical and chemical characters that have been processed. This effect was delivered by the holding capacity increase, ammonium ions, inorganic phosphorus, total nitrogen, the carbon and the organic matter in these soils. This research is to show that sewage sludge are rich in easily mineralizable organic matter and are supposed to be the most suitable for the restoration of soil most impacted by the antropozoogene action. These contributions would quickly revitalize these soils by labile resource inputs.展开更多
基金The financial supports of the National Innovation Office (TECH_09-A4-2009-0129, SOILUTIL project, the New Hungary Development Plan (TáMOP-4.2.1/B-09/1/KMR-2010-0002 BME R + D + I project)the Hungarian State and the European Union and co-financed by the European Social Fund (TáMOP 4.2.4.A-1)
文摘Red mud, the by-product of aluminum production, has been regarded as a problematic residue all over the world. Its storage involves risks as evidenced by the Ajka red mud spill,an accident in Hungary where the slurry broke free, flooding the surrounding areas. As an immediate remediation measure more than 5 cm thick red mud layer was removed from the flooded soil surface. The removed red mud and soil mixture（RMSM） was transferred into the reservoirs for storage. In this paper the application of RMSM is evaluated in a field study aiming at re-utilizing waste, decreasing cost of waste disposal and providing a value-added product. The purpose was to investigate the applicability of RMSM as surface layer component of landfill cover systems. The field study was carried out in two steps： in lysimeters and in field plots. The RMSM was mixed at ratios ranging between 0 and 50% w/w with low quality subsoil（LQS） originally used as surface layer of an interim landfill cover. The characteristics of the LQS ＋ RMSM mixtures compared to the subsoil（LQS） and the RMSM were determined by physical–chemical, biological and ecotoxicological methods. The addition of RMSM to the subsoil（LQS） at up to 20% did not result any ecotoxic effect, but it increased the water holding capacity. In addition, the microbial substrate utilization became about triple of subsoil（LQS） after 10 months. According to our results the RMSM mixed into subsoil（LQS） at20% w/w dose may be applied as surface layer of landfill cover systems.
基金supported by the basic research program from the Institute of Earthquake Science, China Earthquake Administration (0207690233)the Earthquake Science Foundation, China (C07002)the National Natural Science Foundation of China (40774036)
文摘The mobility of Cu2+, Zn2+, Ni2+, and Cd2+ in soils treated with red mud was experimentally studied to explore the feasibility of remediation of smelter-contaminated soils. Red mud samples were collected with the Bayer process (BRM) and confederate process (CRM) in the Aluminous Plant of Guizhou Province. Two farmed soil samples were collected from the Niujiaotang mining area, Guizhou Province, Southwest China. One sample was weakly polluted by fly ash; and the other was polluted severely by waste water from the smelter. For evaluating the potential of remediation, the concentrations of free metal ions and the distributions of metals in the soil were determined. The concentrations of free metal ions were measured by using the Donnan Membrane Technique, and the contributions of soil sorbents to the heavy metals adsorptions were calculated with Equilibrium Calculation of Speciation and Transport (ECOSAT). BRM reduced the concentrations of free metal ions in two kinds of soils, while CRM only favored the decrease of the concentrations of free metal ions in seriously contaminated soils. The experimental data also showed a tendency that the concentrations of free metal ions decreased proportionally with the amount of added red mud, which resulted from the increasing adsorption of heavy metal ions in the form of metal ion hydroxides.
基金Project(20877026)supported by the National Natural Science Foundation of China
文摘A novel method to prepare soil nutrient amendment by calcining a mixture of white mud and potassium feldspar and its environmental assessment were investigated.Under the optimal conditions of a blending mass ratio of 70-30 for white mud to potassium feldspar,a calcination temperature of 1 000℃,a calcination time of 1.5 h and spherulitic diameter of 2.0 cm,the calcined product,as a soil nutrient amendment,could be prepared with the following nutrient composition(mass fraction):K2O 4.16%,CaO 23.43%,MgO 5.04%,SiO2 22.92%,SO4 2-3.71%,and Cl -3.87%in 0.1 mol/L citric acid solution.The concentrations of heavy metals in the calcined product and the emission concentrations of harmful gases from a mixture of white mud and potassium feldspar during calcination process could qualify the National Standards without causing secondary environmental pollution.
文摘The effects of sugar mill mud application on the availability of nutrients for plant uptake were investigated. Mill mud generated from conventional sugar mill operations was applied in three different rates and a leafy vegetable, locally called “PuiShak” or Indian spinach (Basellarubra L.) was grown for 60 days as a test crop in a pot culture experiment. Crop yield and essential nutrients like N, P, K and Zn uptake concentration was determined to come up with an inference that higher doses of mill mud application impose better effect on root and shoot uptake of these elements. A little infraction was observed for nitrogen uptake by plants for the maximum dose.
文摘According to a lot of hydrological and environmental monitoring data, the condition of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is described. The occurrence and development of soil and water loss is analyzed. The conclusion is that: (1) generally, the situation of soil and water loss in the Lancang River Mekong River watershed (in Yunnan section, China) is light, however, soil and water loss in some regions is serious, especially in the middle reach area of the river; (2) soil and water loss in the Lancang River Mekong River (in Yunnan section, China) watershed presents developing tendency and it is mainly caused by human beings. In accordance with these results, the control measures for soil and water loss are discussed.
文摘In order to preserve the environment, various treatment processes of wastewater discharges are used. Anaerobic digestion is part and allows among other things the production of sludge. The use of sewage sludge in semi arid, characterized by a binding climate, anthropozoogenic pressure and erosion, more increasingly important, is a solution for the restoration of degraded forest lands. In this study, the effect of an intake of composts from urban sewage sludge on soil quality has been studied in-situ soils degraded in semi arid area. The research followed in this work methodology is the first to evaluate the effectiveness of contribution of compost over time on the restoration of the physico-chemical quality of forest soils, then to evaluate the effectiveness of compost quality depending on the state of disturbance of the ecosystem to restore the chemical quality of these soils. Our results show a significant effect of sewage sludge on soil’s physical and chemical characters that have been processed. This effect was delivered by the holding capacity increase, ammonium ions, inorganic phosphorus, total nitrogen, the carbon and the organic matter in these soils. This research is to show that sewage sludge are rich in easily mineralizable organic matter and are supposed to be the most suitable for the restoration of soil most impacted by the antropozoogene action. These contributions would quickly revitalize these soils by labile resource inputs.
