The productivity of China’s nonferrous metals industry during 1980-1990 has been analysed. The important factors which constrain the productivity of the nonferrous metals industry have been studied, the methods of im...The productivity of China’s nonferrous metals industry during 1980-1990 has been analysed. The important factors which constrain the productivity of the nonferrous metals industry have been studied, the methods of improving the productivity of the nonferrous metals industry have been discussed.展开更多
Indiscriminate handling and disposal of industrial effluents into the environment represents one of the major sources of environmental pollution which invariably affect plants, animals and humans. This study assessed ...Indiscriminate handling and disposal of industrial effluents into the environment represents one of the major sources of environmental pollution which invariably affect plants, animals and humans. This study assessed heavy metal concentration in soils and plants around industries in Agbara industrial estate, Ogun State, Nigeria. Soil and plant samples were collected from four industries and analyzed for lead (Pb), cadmium (Cd), copper (Cu), chromium (Cr) and nickel (Ni). The pH, organic matter content and cation exchange capacity of the soil samples, as well as bioaccumulation factor (BAF) and translocation factor (TF) of the plant samples were examined. The heavy metal concentration order of the soil and plant samples was Pb ?1, 50 mg kg?1, 10 mg kg?1 and 50 mg kg?1 respectively) while Cd was above WHO tolerance limit (3 mg kg?1). Also, Pb, Cd, Cu, and Cr in most plant samples were above WHO tolerance limits (10 mg kg?1, 0.30 mg kg?1, 10 mg kg?1 and 1.5 mg kg?1 respectively). Statistical differences (P Cyperus iria, Alternanthera sessilis, C. esculentus, A. brasiliana, and Megathyrsus maximus are probable accumulators of heavy metals.展开更多
In this study, eleven soil samples and twenty-twoplants samples were collected in the vicinity of eleven industries and a thermal station was analyzed for zinc, copper, iron, lead and cadmium. Soil sample from Egbin t...In this study, eleven soil samples and twenty-twoplants samples were collected in the vicinity of eleven industries and a thermal station was analyzed for zinc, copper, iron, lead and cadmium. Soil sample from Egbin thermal station had the highest concentration of Zn (141.06 mg/kg) and Cu (131.70 mg/kg). Soil from international textile had the highest level of Fe and the soil from Ni-chemtex had the highest concentration Pb and Cd was the highest in soil from Guinness (28.91 mg/kg, 59.80 mg/kg and 1.72 mg/kg respectively). The highest concentrations of the heavy metals were observed from different plants species. Analyses of variance (p < 0.05) showed that heavy metal variation in plant and soil samples were not significant (p > 0.5). There were positive correlations between the heavy metals in the soils and the plant samples indicated that the plants obtained the heavy metals from the soil. Plants having BCF values less than one had limited ability to accumulate, translocate and phytoextract heavy metals. These plants in this study with higher Bioconcentration Factor value especially those greater than one (Croton lobatus, Borreria sp., Cy-athula prostrata, Lantana camara, Ficus sp., Mimosa pudica, Eclipta prostrata, Commelina sp. etc.) were suggested for further research and assessment on their bioaccumulation abilities and phy-toremediation potential.展开更多
Wastewater mixed with industrial effluents is used for irrigation in Gadoon Industrial estate and thus contaminating soil. This soil was tested for heavy metal content by using atomic absorption spectrophotometer (per...Wastewater mixed with industrial effluents is used for irrigation in Gadoon Industrial estate and thus contaminating soil. This soil was tested for heavy metal content by using atomic absorption spectrophotometer (perkin elmer 700) and compared with control soil irrigated with tube well water at seven selected spots. Accumulation of the toxic metal was significantly greater in the soil irrigated with industrial effluent than control soil (p < 0.05). Manganese (Mn) was the most significant pollutant, accumulated up to 9.95 ppm in the soil irrigated with industrial waste water. It was found that the samples were containing Zn in the range of 1.596 - 6.288, Cu 0.202 - 1.236, Co 0.074 - 0.115, Ni 0.0002 - 0.544, Cr 0.243 - 0.936, Mn 3.667 - 9.955 and Pb 0.488 - 1.259 ppm. No sample was containing the heavy metal above the critical level mentioned in typical and unsafe heavy metal levels in soil.展开更多
The waste products, such as induction furnace slag, ladle furnace slag, air pollution control dust, and ramming mass collected from major iron processing industries in Chittagong, Bangladesh were analyzed for heavy me...The waste products, such as induction furnace slag, ladle furnace slag, air pollution control dust, and ramming mass collected from major iron processing industries in Chittagong, Bangladesh were analyzed for heavy metals and naturally radioactive elements. The concentrations of heavy metals Fe, Cr, Mn, Co, Cd, Ni, Pb, Cu and Zn were obtained from atomic absorption spectrophotometer (AAS) analysis with flame atomizer and the radioactivities due to 226Ra, 232Th and 40K were determined using high purity germanium (HPGe) detector of well shielded gamma-ray counting system. From the mean specific activities of the above three natural radionuclides in the investigated samples, the radium equivalent activity (Raeq) and the external hazard index (Hex) were calculated. The study showed the prospect of contamination of environmental materials (viz., soil, water, air, plant) due to many of these investigated elements by using the collected waste products in landfill. The chemical process of ion exchange indicates that the elevated heavy metals in soil can play a role to increase the natural radioactivity of the soil. The obtained Raeq as well as Hex indicated the insignificant radiation hazard due to the activities of primordial radionuclides found in the investigated samples.展开更多
In April this year China National Nonferrous Metals Industries Corporation(CNNMIC)performed the Tenth Anniversary Ceremony.In the past decade the CNNMIC realized“fivedoublings”,i.e.the output,profits tax,fixed asset...In April this year China National Nonferrous Metals Industries Corporation(CNNMIC)performed the Tenth Anniversary Ceremony.In the past decade the CNNMIC realized“fivedoublings”,i.e.the output,profits tax,fixed assets,enterprise revenue and personal income展开更多
On the 3 April 1993,in the Great Hall of the People a ceremony of the tenth anniversarywas held by CNNMIC.The Vice-premier Li Lanqing and old leaders Fang Yi,Wang Heshouet al attended this ceremony.Lu Dong,Yuan Baohua...On the 3 April 1993,in the Great Hall of the People a ceremony of the tenth anniversarywas held by CNNMIC.The Vice-premier Li Lanqing and old leaders Fang Yi,Wang Heshouet al attended this ceremony.Lu Dong,Yuan Baohua,Gao Yangwen and Chen Jinhua et alministerial representatives are present also.The ambassadors and/or envoys from Romania,展开更多
China’s non-ferrous metals industry has constantly maintained a steady, rapid and healthy development since the reform and opening to the outside world. By the end of 1994, the annual output often kinds of common non...China’s non-ferrous metals industry has constantly maintained a steady, rapid and healthy development since the reform and opening to the outside world. By the end of 1994, the annual output often kinds of common non-ferrous metals such as copper, aluminium, lead, and zinc had reached 3.701 million tons, a 12.2 percent increase over the previous year; the qualification rate of principal products and the output value rate of good quality products all achieved an increase over the previous year. China has展开更多
The China Non-ferrous MetalsIndustry Corporation has putforward ten development policiesfor the Ninth Five-year Plan period,according to the central government’sinstruction to change the way of economicgrowth,and rai...The China Non-ferrous MetalsIndustry Corporation has putforward ten development policiesfor the Ninth Five-year Plan period,according to the central government’sinstruction to change the way of economicgrowth,and raise the integral quality andbenefit of the national economy:展开更多
Heavy metals pollution in Jiaozhou Bay was studied in Ruditapes. philippinarum, a bioindicator of seawater pollution. Heavy metals in soda industry wastes “white mud” were also studied. Comparison of microwave diges...Heavy metals pollution in Jiaozhou Bay was studied in Ruditapes. philippinarum, a bioindicator of seawater pollution. Heavy metals in soda industry wastes “white mud” were also studied. Comparison of microwave digestion method with general digestion method revealed that microwave digestion is superior to general digestion in precision, recovery, digestion speed and efficiency, etc. Cd concentration in Hongdao R. philippinarum samples exceeded the national standard by 0.046 mg/kg, that of Yinghai sample by 0.02 mg/kg, and that of Hongshiya sample by 0.22 mg/kg. Sample Pb concentration in Hongshiya was found to exceed the national standard by 0.02 mg/kg. However the heavy metals concentration in R. philippinarum near the Qingdao Alkaline Factory was complied with the standard. This was proved by Penaeus chinensis culture experiment. Therefore, the possible contamination source may come from other land areas.展开更多
The present study demonstrates distribution and chemical forms of heavy metals in soils of the AImalyk mining and smelting industrial area along five transects. The study area is located in Almalyk, Uzbekistan, where ...The present study demonstrates distribution and chemical forms of heavy metals in soils of the AImalyk mining and smelting industrial area along five transects. The study area is located in Almalyk, Uzbekistan, where the intensification of industrial enterprises negatively impacts the environment. The distribution of 17 heavy metals (Cu, Zn, Pb, Sc, V, Cr, Co, Ni, Ga, Rb, Sr, Y, Zr, Nb, Ba, Th, and U) were studied in 21 sampling locations (21×3=63 soil samples) along five radial transects with a total length of 60 km downwind deposition gradient. Soil samples were collected from the upper layer (0-10 cm) at 4-6 km intervals. As a result of X-ray fluorescence spectrometry analyses by using X -ray fluorescence spectroscopy (XRF, Philips Analytical Ink, USA ), a significant decrease in heavy metal (Cu, Zn, Pb) deposition was found going from the source in a downwind direction. Soil samples taken from the first location (near the pollution sources) showed higher concentrations of Cu, Zn and Pb, and lower concentrations with increasing distance from the source. Obtained data showed different impact of pollution sources to heavy metal deposition and distribution in soils. The Almalyk mining and smelting complex is the major source of Pb, Zn and Cu enrichment in soils. Distribution of other trace elements does not exceed background content and suggests lithogenic background. This allowed us to divide these elements into two groups: (1) technogenic (Cu, Zn and Pb); and (2) lithogenic (Sc, V, Cr, Co, Ni, Ga, Rb, Sr, Y, Zr, Nb, Ba, Th and U) origins.展开更多
In this work, a thorough examinations on the extractability of zinc and lead present in the steelmaking dusts using alkaline leaching process and the effectiveness of the zinc and lead separation in the resultant leac...In this work, a thorough examinations on the extractability of zinc and lead present in the steelmaking dusts using alkaline leaching process and the effectiveness of the zinc and lead separation in the resultant leaching solutions using sulfide precipitation method were made. It was found that only about 53% of zinc and over 70% of the lead could be leached out of the dusts, while the other 47% of zinc and 30% of lead were left in the leaching residues. The zinc and lead in the resultant leaching solution can be effectively and selectively separated. When the weight ratio of sodium sulfide (M.W. = 222-240) to Pb was kept at 1.8, the lead in the solution could be precipitated out quantitatively while all the zinc was remained in the solution. The zinc left in the solution can be further recovered by the addition of extra sodium sulfide with a weight ratio of sodium sulfide to the zinc over 2.6. The resultant filtrate can be recycled to the leaching of dust in the next leaching process.展开更多
Lake contamination by anthropogenic activities has become a serious threat to the aquatic ecosystem due to the presence of a high concentration of toxic heavy metals.In this study,a contaminated Lake Hussain Sagar in ...Lake contamination by anthropogenic activities has become a serious threat to the aquatic ecosystem due to the presence of a high concentration of toxic heavy metals.In this study,a contaminated Lake Hussain Sagar in India was assessed for toxic heavy metal pollutants at sites associated with industrial discharges and idol immersion activities.The observed high concentration of As,Cd,Pb,Zn,Cu,and Ni in the surface water was due to industrial effluent discharge.About 1.5 times the high concentration of the same elements were observed in surface sediments(0-10 cm)by both industrial discharges and idol immersion activities,compared to deep sediments(0-40 cm)associated only with industrial discharge.The depth-wise variation of heavy metal concentration in surface sediments is due to sorption and settling behavior of suspended solids;whereas in deep sediment,it is due to constant loading of effluents,over a period of time.The sorption capacity of surface sediments is in increasing order as Pb>Cd≥Ni>Cr>Zn>Cu,and the desorption revealed that Pb and Cu were retained to a greater extent due to high clay and organic content.By fractionation study,20-50%of Zn and 50-80%of Cd were associated with exchangeable and carbonate fraction of sediments.By risk assessment code,Zn and Cd are classified under high risk to a very high-risk category,and Cr,Pb,Ni,and Cu are classified under the medium risk category.The enrichment factor value of sediments for Cd(20.42-119.48),Zn(2.19-4.85),Cu(2.02-3.19),and Pb(2.85-7.72)signifies the significant pollution by anthropogenic activities.Therefore,this study evaluates the intensity and distribution of heavy metals in the lake environment for remediation and restoration of the lake ecosystem.展开更多
To Lich River (TLR) system receives wastewaters from a population of nearly two million people and 100 manufactories of five industrial zones in inner city Hanoi, Vietnam. To improve quality of TLR, the embankment was...To Lich River (TLR) system receives wastewaters from a population of nearly two million people and 100 manufactories of five industrial zones in inner city Hanoi, Vietnam. To improve quality of TLR, the embankment was carried out in 1998 and finished in 2002, resulted in width of 20 - 45 m, depth of 2 - 4 m, and maximum water flow capacity of 30 m3/s. Water and sediment quality indices based on heavy metal concentrations were used to evaluate current river environment compared to that of pre-embankment. Mass balance model was employed to estimate total metal loads for specific river reaches, which corresponds to various types of wastewater discharged along the river. The results indicated that currently there is about284,000 m3sediment accumulated in TLR bed, which is under high contamination of Cr, Mn, Fe, Ni Cu, Zn, As, Cd, and Pb with a total of 7347 tons of all concerned metals. Domestic-discharged river reaches received much lower metal loads, roughly 8% - 28% compared to river reaches of both domestic and industrial inputs. Total load of all nine concerned metals at the end of TLR is161.7 kg/day, which is finally discharged to Nhue River at South Hanoi. Water quality was improved much right after finishing embankment, then it gradually deteriorated. Meanwhile, sediment quality became even much worse after embankment. Relative river quality index as equal weight for both water and sediment quality indices indicated that quality of TLR was not much improved after the embankment. It even became worse due to the urbanization in recent years.展开更多
This The mineral potential in Egypt is quite high. Almost all sorts of industrial minerals such as metallic and non-metallic commodities exist in commercial amounts. However, Egypt imports many of the mineral commodit...This The mineral potential in Egypt is quite high. Almost all sorts of industrial minerals such as metallic and non-metallic commodities exist in commercial amounts. However, Egypt imports many of the mineral commodities needed for the local mineral industries. The main reason for this is that the investors, either the governmental or the private sectors, refrain from investing into the mineral industry for prospecting, evaluation, and developing the mining and mineral processing technologies. This is because the return on investment in the mining industry is generally low and the pay back period is relatively long compared with easy-to-get money projects. Another reason is the disarray of the mining laws and regulations and lack of administrative capability to deal with domestic and international investors and solve the related problems. Also, lack of skilled personnel in the field of mining and mineral processing is an additional factor for the set back of the mining industry in Egypt. This is why the mining technology in Egypt is not very far from being primitive and extremely simple, with the exception of the underground mining of coal, North of Sinai, and Abu-Tartur phosphate mining, where fully automated long wall operations are designed. Also, the recent gold and tin-tantalum-niobium projects are being designed on modern surface mining and mineral processing technologies. The present review presents an overview of the most important metallic mineral commodities in Egypt, their geological background, reserves and production rates. A brief mention of the existing technologies for their exploitation is also highlighted.展开更多
The present study demonstrates the distribution of heavy metals in soils of Almalyk mining and smelting industrial area along the 5 transects.The study area is located in Almalyk,Uzbekistan,where the intensification o...The present study demonstrates the distribution of heavy metals in soils of Almalyk mining and smelting industrial area along the 5 transects.The study area is located in Almalyk,Uzbekistan,where the intensification of industrial enterprises negatively impact on the environment.The distribution of 17 heavy metals (Cu,Zn,Pb,Sc,V,Cr,Co,Ni,Ga,Rb,Sr,Y,Zr,Nb, Ba,Th,and U)were studied in 21 sampling locations (21×3=63 soil samples)along the 5 radial transects with the total length of 60 km downwind展开更多
The trace metals analysis in synodontis membranaceus (head and tail), bottom sediments, Asystasia Gangetica and Platostoma Africanium were carried out using atomic absorption spectrometer of model Perkin Elmer 3110. ...The trace metals analysis in synodontis membranaceus (head and tail), bottom sediments, Asystasia Gangetica and Platostoma Africanium were carried out using atomic absorption spectrometer of model Perkin Elmer 3110. Metals analysed were copper, nickel, mangenese, chromium, iron lead and cobalt. These metals were detected in the above samples. Vegetation samples concentration in copper, manganese, chromium, iron and cobalt were higher than those obtained in bottom sediments. The tail part of the fish contents of trace metals were also higher than those of the head. The results obtained in this work exceeded the results of water analysis carried out by Omoregha on the same river. Metals such as copper, nickel, manganese and chromium were below detection limit in the water from the same river. The bioaccumulation of these trace metals in these samples were traced to activities of Delta Glass Factory.展开更多
The present work discusses the mineralogy, saturated adsorption of ammonium and adsorption of heavy metal ions (Cu^2+, Pb^2+ and Zn^2+) on industrial vermiculite samples from the Yuli Mine in Xinjiang Autonomous ...The present work discusses the mineralogy, saturated adsorption of ammonium and adsorption of heavy metal ions (Cu^2+, Pb^2+ and Zn^2+) on industrial vermiculite samples from the Yuli Mine in Xinjiang Autonomous Region. The saturated adsorption capacity of ammonium and the affection factors of adsorption of Cu^2+, Pb^2+ and Zn^2+ are discussed on the basis of the mineralogical characteristics of the industrial vermiculite samples. The saturated adsorption capacities of ammonium are between 56.02 and 98.42 mmol/100g. The time of adsorption equilibrium is about 30-60 min, and the pH values and concentration of the ion solution significantly affect the adsorption capacities of the heavy metal ions. The adsorption capabilities of the heavy metal ions on industrial vermiculite are almost the same in the low ion concentration solutions, characterized by a sequence of Zn^2+〉Pb^2+〉Cu^2+ for adsorption capacity in solutions with relatively high ion concentration. The results have practical significance for the application of the industrial vermiculite to treating wastewater containing ammonium or heavy metal ions.展开更多
Heavy metals were determined in topsoils around a major industrial estate co-located with a housing estate in the southwestern region of Nigerian. Samples were collected on three-monthly basis for 18 months, from the ...Heavy metals were determined in topsoils around a major industrial estate co-located with a housing estate in the southwestern region of Nigerian. Samples were collected on three-monthly basis for 18 months, from the industrial waste dumpsites, industrial area, residential area, around an effluent channel, outskirts of the estate and control sites. Average levels of Cu (2850 ± 3340 mg/kg), Pb (768 ± 450 mg/kg) and Ni (105 ± 30 mg/kg) at the dumpsites were significantly higher than other locations. At the industrial area and effluent channels, Pb and Cr levels were slightly elevated compared with other metals. Metal levels at the residential area and outskirts of the estate were about the levels in the control. Generally, the degree of contamination within the vicinity of the estate was of the order Cu>Pb>Ni>Cd>Co>Cr. Average total bioavailable (non-residual) fraction of the metals consisted of 52.0% of the metal load, with this fraction for Cd and Pb being 73.9% and 60.7% respectively. Topsoils around the dumpsite were evidently polluted with high levels of copper and lead. Seepage of leachate from the dumpsite has the potential of contaminating ground water reserves. Improper disposal of industrial solid wastes appears to be the likely source of metal pollution in the industrial estate. Heavy metal pollution in the estate can therefore be significantly reduced by prompt and proper disposal of generated solid wastes, and the application of particulate scrubbers in the industries.展开更多
It has been observed that the portable water quality obtained from various locations in Kano Metropolis has shown greater variations in the recent past. Attempts have been made to ascertain the reasons for the variati...It has been observed that the portable water quality obtained from various locations in Kano Metropolis has shown greater variations in the recent past. Attempts have been made to ascertain the reasons for the variations even though the supplies were from only two treatments plants that obtain their raw water from the same source. A total of 92 water samples comprising of raw (from plants) and treated (from the plants and taps) were collected during rainy and dry seasons between April 2010 and May, 2012 and analyzed using standard analytical techniques. The results of analysis gave the physiochemical properties with range as follows: pH (0.06 ± 6.7 - 6.04 ± 0.02) conductivity (7.23 ±0.04 - 13.33 ± 0.22 S/Cm), turbidity (5.00 ± 0.01 - 449.22 ±1.32 NTU), suspended solids (107.33±3.45 - 712.11 ±5.33 mg/dm3), total dissolved solids (18.50 ± 0.85 -186 .78 ± 2.48 mg/dm3 ), alkalinity (12.53± 0.32 - 80.75 ± 1.23 mg/dm3) and hardness (29.50 ± 1.22 - 58.67 ± 2.34 mg/dm3). The pH values were generally acidic while the turbidity and total solid especially in some locations were higher than the permissible levels set by the World Health Organization for portable water. The concentration of heavy metals (mg/dm3) were found in the following ranges Fe (0.10 ± 0.04 - 0.30 ± 0.02), Cu (0.01 ± 0.001 - 0.03 ± 0.002), Zn (0.13 ± 0.06 - 0.39 ±0.02), Pb (0.03 ± 0.01 - 0.17 ± 0.02), Mn (0.03 ± 0.004 - 0.13 ± 0.003), Cr (0.10 ± 0.04 - 0.31 ± 0.03). The highest values of Fe, Cu and Mn were recorded along the older distribution channel of Challawa. The levels of Pb and Cr were generally high in both routes which are also observed in the raw water used at the two treatments plants. The results obtained from heavy metal concentrations fell within the maximum allowable limit set by the World Health Organization for portable water except in the cases of Pb and Cr. The high Fe, Mn, Cu levels as obtained in the Challawa route were attributed to leaching from rusting in the old galvanized metal pipe-work in the distribution channel. The levels of chromium and lead were similar in the two networks showing that the raw water used in the both treatment plants were responsible for the high values obtained and were not effectively removed by the treatment processes.展开更多
基金The project was financially supported by the Chima National Natural Science Foundation
文摘The productivity of China’s nonferrous metals industry during 1980-1990 has been analysed. The important factors which constrain the productivity of the nonferrous metals industry have been studied, the methods of improving the productivity of the nonferrous metals industry have been discussed.
文摘Indiscriminate handling and disposal of industrial effluents into the environment represents one of the major sources of environmental pollution which invariably affect plants, animals and humans. This study assessed heavy metal concentration in soils and plants around industries in Agbara industrial estate, Ogun State, Nigeria. Soil and plant samples were collected from four industries and analyzed for lead (Pb), cadmium (Cd), copper (Cu), chromium (Cr) and nickel (Ni). The pH, organic matter content and cation exchange capacity of the soil samples, as well as bioaccumulation factor (BAF) and translocation factor (TF) of the plant samples were examined. The heavy metal concentration order of the soil and plant samples was Pb ?1, 50 mg kg?1, 10 mg kg?1 and 50 mg kg?1 respectively) while Cd was above WHO tolerance limit (3 mg kg?1). Also, Pb, Cd, Cu, and Cr in most plant samples were above WHO tolerance limits (10 mg kg?1, 0.30 mg kg?1, 10 mg kg?1 and 1.5 mg kg?1 respectively). Statistical differences (P Cyperus iria, Alternanthera sessilis, C. esculentus, A. brasiliana, and Megathyrsus maximus are probable accumulators of heavy metals.
文摘In this study, eleven soil samples and twenty-twoplants samples were collected in the vicinity of eleven industries and a thermal station was analyzed for zinc, copper, iron, lead and cadmium. Soil sample from Egbin thermal station had the highest concentration of Zn (141.06 mg/kg) and Cu (131.70 mg/kg). Soil from international textile had the highest level of Fe and the soil from Ni-chemtex had the highest concentration Pb and Cd was the highest in soil from Guinness (28.91 mg/kg, 59.80 mg/kg and 1.72 mg/kg respectively). The highest concentrations of the heavy metals were observed from different plants species. Analyses of variance (p < 0.05) showed that heavy metal variation in plant and soil samples were not significant (p > 0.5). There were positive correlations between the heavy metals in the soils and the plant samples indicated that the plants obtained the heavy metals from the soil. Plants having BCF values less than one had limited ability to accumulate, translocate and phytoextract heavy metals. These plants in this study with higher Bioconcentration Factor value especially those greater than one (Croton lobatus, Borreria sp., Cy-athula prostrata, Lantana camara, Ficus sp., Mimosa pudica, Eclipta prostrata, Commelina sp. etc.) were suggested for further research and assessment on their bioaccumulation abilities and phy-toremediation potential.
文摘Wastewater mixed with industrial effluents is used for irrigation in Gadoon Industrial estate and thus contaminating soil. This soil was tested for heavy metal content by using atomic absorption spectrophotometer (perkin elmer 700) and compared with control soil irrigated with tube well water at seven selected spots. Accumulation of the toxic metal was significantly greater in the soil irrigated with industrial effluent than control soil (p < 0.05). Manganese (Mn) was the most significant pollutant, accumulated up to 9.95 ppm in the soil irrigated with industrial waste water. It was found that the samples were containing Zn in the range of 1.596 - 6.288, Cu 0.202 - 1.236, Co 0.074 - 0.115, Ni 0.0002 - 0.544, Cr 0.243 - 0.936, Mn 3.667 - 9.955 and Pb 0.488 - 1.259 ppm. No sample was containing the heavy metal above the critical level mentioned in typical and unsafe heavy metal levels in soil.
文摘The waste products, such as induction furnace slag, ladle furnace slag, air pollution control dust, and ramming mass collected from major iron processing industries in Chittagong, Bangladesh were analyzed for heavy metals and naturally radioactive elements. The concentrations of heavy metals Fe, Cr, Mn, Co, Cd, Ni, Pb, Cu and Zn were obtained from atomic absorption spectrophotometer (AAS) analysis with flame atomizer and the radioactivities due to 226Ra, 232Th and 40K were determined using high purity germanium (HPGe) detector of well shielded gamma-ray counting system. From the mean specific activities of the above three natural radionuclides in the investigated samples, the radium equivalent activity (Raeq) and the external hazard index (Hex) were calculated. The study showed the prospect of contamination of environmental materials (viz., soil, water, air, plant) due to many of these investigated elements by using the collected waste products in landfill. The chemical process of ion exchange indicates that the elevated heavy metals in soil can play a role to increase the natural radioactivity of the soil. The obtained Raeq as well as Hex indicated the insignificant radiation hazard due to the activities of primordial radionuclides found in the investigated samples.
文摘In April this year China National Nonferrous Metals Industries Corporation(CNNMIC)performed the Tenth Anniversary Ceremony.In the past decade the CNNMIC realized“fivedoublings”,i.e.the output,profits tax,fixed assets,enterprise revenue and personal income
文摘On the 3 April 1993,in the Great Hall of the People a ceremony of the tenth anniversarywas held by CNNMIC.The Vice-premier Li Lanqing and old leaders Fang Yi,Wang Heshouet al attended this ceremony.Lu Dong,Yuan Baohua,Gao Yangwen and Chen Jinhua et alministerial representatives are present also.The ambassadors and/or envoys from Romania,
文摘China’s non-ferrous metals industry has constantly maintained a steady, rapid and healthy development since the reform and opening to the outside world. By the end of 1994, the annual output often kinds of common non-ferrous metals such as copper, aluminium, lead, and zinc had reached 3.701 million tons, a 12.2 percent increase over the previous year; the qualification rate of principal products and the output value rate of good quality products all achieved an increase over the previous year. China has
文摘The China Non-ferrous MetalsIndustry Corporation has putforward ten development policiesfor the Ninth Five-year Plan period,according to the central government’sinstruction to change the way of economicgrowth,and raise the integral quality andbenefit of the national economy:
基金This study is supported by Project 973 (NO.2002CB412402), and key project of the Chinese Academy of Sciences (Grant NO.KJCX315W-215).
文摘Heavy metals pollution in Jiaozhou Bay was studied in Ruditapes. philippinarum, a bioindicator of seawater pollution. Heavy metals in soda industry wastes “white mud” were also studied. Comparison of microwave digestion method with general digestion method revealed that microwave digestion is superior to general digestion in precision, recovery, digestion speed and efficiency, etc. Cd concentration in Hongdao R. philippinarum samples exceeded the national standard by 0.046 mg/kg, that of Yinghai sample by 0.02 mg/kg, and that of Hongshiya sample by 0.22 mg/kg. Sample Pb concentration in Hongshiya was found to exceed the national standard by 0.02 mg/kg. However the heavy metals concentration in R. philippinarum near the Qingdao Alkaline Factory was complied with the standard. This was proved by Penaeus chinensis culture experiment. Therefore, the possible contamination source may come from other land areas.
基金supported by NATO SPS programs as reintegration grant to Dr.Nosir Shukurov
文摘The present study demonstrates distribution and chemical forms of heavy metals in soils of the AImalyk mining and smelting industrial area along five transects. The study area is located in Almalyk, Uzbekistan, where the intensification of industrial enterprises negatively impacts the environment. The distribution of 17 heavy metals (Cu, Zn, Pb, Sc, V, Cr, Co, Ni, Ga, Rb, Sr, Y, Zr, Nb, Ba, Th, and U) were studied in 21 sampling locations (21×3=63 soil samples) along five radial transects with a total length of 60 km downwind deposition gradient. Soil samples were collected from the upper layer (0-10 cm) at 4-6 km intervals. As a result of X-ray fluorescence spectrometry analyses by using X -ray fluorescence spectroscopy (XRF, Philips Analytical Ink, USA ), a significant decrease in heavy metal (Cu, Zn, Pb) deposition was found going from the source in a downwind direction. Soil samples taken from the first location (near the pollution sources) showed higher concentrations of Cu, Zn and Pb, and lower concentrations with increasing distance from the source. Obtained data showed different impact of pollution sources to heavy metal deposition and distribution in soils. The Almalyk mining and smelting complex is the major source of Pb, Zn and Cu enrichment in soils. Distribution of other trace elements does not exceed background content and suggests lithogenic background. This allowed us to divide these elements into two groups: (1) technogenic (Cu, Zn and Pb); and (2) lithogenic (Sc, V, Cr, Co, Ni, Ga, Rb, Sr, Y, Zr, Nb, Ba, Th and U) origins.
文摘In this work, a thorough examinations on the extractability of zinc and lead present in the steelmaking dusts using alkaline leaching process and the effectiveness of the zinc and lead separation in the resultant leaching solutions using sulfide precipitation method were made. It was found that only about 53% of zinc and over 70% of the lead could be leached out of the dusts, while the other 47% of zinc and 30% of lead were left in the leaching residues. The zinc and lead in the resultant leaching solution can be effectively and selectively separated. When the weight ratio of sodium sulfide (M.W. = 222-240) to Pb was kept at 1.8, the lead in the solution could be precipitated out quantitatively while all the zinc was remained in the solution. The zinc left in the solution can be further recovered by the addition of extra sodium sulfide with a weight ratio of sodium sulfide to the zinc over 2.6. The resultant filtrate can be recycled to the leaching of dust in the next leaching process.
基金the support from Frontier Areas of Science and Technology—Centre of Excellence(FAST-CoE)in Sustainable Development at Indian Institute of Technology Hyderabad,funded by the Ministry of Human Resource Development,India。
文摘Lake contamination by anthropogenic activities has become a serious threat to the aquatic ecosystem due to the presence of a high concentration of toxic heavy metals.In this study,a contaminated Lake Hussain Sagar in India was assessed for toxic heavy metal pollutants at sites associated with industrial discharges and idol immersion activities.The observed high concentration of As,Cd,Pb,Zn,Cu,and Ni in the surface water was due to industrial effluent discharge.About 1.5 times the high concentration of the same elements were observed in surface sediments(0-10 cm)by both industrial discharges and idol immersion activities,compared to deep sediments(0-40 cm)associated only with industrial discharge.The depth-wise variation of heavy metal concentration in surface sediments is due to sorption and settling behavior of suspended solids;whereas in deep sediment,it is due to constant loading of effluents,over a period of time.The sorption capacity of surface sediments is in increasing order as Pb>Cd≥Ni>Cr>Zn>Cu,and the desorption revealed that Pb and Cu were retained to a greater extent due to high clay and organic content.By fractionation study,20-50%of Zn and 50-80%of Cd were associated with exchangeable and carbonate fraction of sediments.By risk assessment code,Zn and Cd are classified under high risk to a very high-risk category,and Cr,Pb,Ni,and Cu are classified under the medium risk category.The enrichment factor value of sediments for Cd(20.42-119.48),Zn(2.19-4.85),Cu(2.02-3.19),and Pb(2.85-7.72)signifies the significant pollution by anthropogenic activities.Therefore,this study evaluates the intensity and distribution of heavy metals in the lake environment for remediation and restoration of the lake ecosystem.
文摘To Lich River (TLR) system receives wastewaters from a population of nearly two million people and 100 manufactories of five industrial zones in inner city Hanoi, Vietnam. To improve quality of TLR, the embankment was carried out in 1998 and finished in 2002, resulted in width of 20 - 45 m, depth of 2 - 4 m, and maximum water flow capacity of 30 m3/s. Water and sediment quality indices based on heavy metal concentrations were used to evaluate current river environment compared to that of pre-embankment. Mass balance model was employed to estimate total metal loads for specific river reaches, which corresponds to various types of wastewater discharged along the river. The results indicated that currently there is about284,000 m3sediment accumulated in TLR bed, which is under high contamination of Cr, Mn, Fe, Ni Cu, Zn, As, Cd, and Pb with a total of 7347 tons of all concerned metals. Domestic-discharged river reaches received much lower metal loads, roughly 8% - 28% compared to river reaches of both domestic and industrial inputs. Total load of all nine concerned metals at the end of TLR is161.7 kg/day, which is finally discharged to Nhue River at South Hanoi. Water quality was improved much right after finishing embankment, then it gradually deteriorated. Meanwhile, sediment quality became even much worse after embankment. Relative river quality index as equal weight for both water and sediment quality indices indicated that quality of TLR was not much improved after the embankment. It even became worse due to the urbanization in recent years.
文摘This The mineral potential in Egypt is quite high. Almost all sorts of industrial minerals such as metallic and non-metallic commodities exist in commercial amounts. However, Egypt imports many of the mineral commodities needed for the local mineral industries. The main reason for this is that the investors, either the governmental or the private sectors, refrain from investing into the mineral industry for prospecting, evaluation, and developing the mining and mineral processing technologies. This is because the return on investment in the mining industry is generally low and the pay back period is relatively long compared with easy-to-get money projects. Another reason is the disarray of the mining laws and regulations and lack of administrative capability to deal with domestic and international investors and solve the related problems. Also, lack of skilled personnel in the field of mining and mineral processing is an additional factor for the set back of the mining industry in Egypt. This is why the mining technology in Egypt is not very far from being primitive and extremely simple, with the exception of the underground mining of coal, North of Sinai, and Abu-Tartur phosphate mining, where fully automated long wall operations are designed. Also, the recent gold and tin-tantalum-niobium projects are being designed on modern surface mining and mineral processing technologies. The present review presents an overview of the most important metallic mineral commodities in Egypt, their geological background, reserves and production rates. A brief mention of the existing technologies for their exploitation is also highlighted.
文摘The present study demonstrates the distribution of heavy metals in soils of Almalyk mining and smelting industrial area along the 5 transects.The study area is located in Almalyk,Uzbekistan,where the intensification of industrial enterprises negatively impact on the environment.The distribution of 17 heavy metals (Cu,Zn,Pb,Sc,V,Cr,Co,Ni,Ga,Rb,Sr,Y,Zr,Nb, Ba,Th,and U)were studied in 21 sampling locations (21×3=63 soil samples)along the 5 radial transects with the total length of 60 km downwind
文摘The trace metals analysis in synodontis membranaceus (head and tail), bottom sediments, Asystasia Gangetica and Platostoma Africanium were carried out using atomic absorption spectrometer of model Perkin Elmer 3110. Metals analysed were copper, nickel, mangenese, chromium, iron lead and cobalt. These metals were detected in the above samples. Vegetation samples concentration in copper, manganese, chromium, iron and cobalt were higher than those obtained in bottom sediments. The tail part of the fish contents of trace metals were also higher than those of the head. The results obtained in this work exceeded the results of water analysis carried out by Omoregha on the same river. Metals such as copper, nickel, manganese and chromium were below detection limit in the water from the same river. The bioaccumulation of these trace metals in these samples were traced to activities of Delta Glass Factory.
基金the National Natural Science Foundation of China (Grant 40102006).
文摘The present work discusses the mineralogy, saturated adsorption of ammonium and adsorption of heavy metal ions (Cu^2+, Pb^2+ and Zn^2+) on industrial vermiculite samples from the Yuli Mine in Xinjiang Autonomous Region. The saturated adsorption capacity of ammonium and the affection factors of adsorption of Cu^2+, Pb^2+ and Zn^2+ are discussed on the basis of the mineralogical characteristics of the industrial vermiculite samples. The saturated adsorption capacities of ammonium are between 56.02 and 98.42 mmol/100g. The time of adsorption equilibrium is about 30-60 min, and the pH values and concentration of the ion solution significantly affect the adsorption capacities of the heavy metal ions. The adsorption capabilities of the heavy metal ions on industrial vermiculite are almost the same in the low ion concentration solutions, characterized by a sequence of Zn^2+〉Pb^2+〉Cu^2+ for adsorption capacity in solutions with relatively high ion concentration. The results have practical significance for the application of the industrial vermiculite to treating wastewater containing ammonium or heavy metal ions.
文摘Heavy metals were determined in topsoils around a major industrial estate co-located with a housing estate in the southwestern region of Nigerian. Samples were collected on three-monthly basis for 18 months, from the industrial waste dumpsites, industrial area, residential area, around an effluent channel, outskirts of the estate and control sites. Average levels of Cu (2850 ± 3340 mg/kg), Pb (768 ± 450 mg/kg) and Ni (105 ± 30 mg/kg) at the dumpsites were significantly higher than other locations. At the industrial area and effluent channels, Pb and Cr levels were slightly elevated compared with other metals. Metal levels at the residential area and outskirts of the estate were about the levels in the control. Generally, the degree of contamination within the vicinity of the estate was of the order Cu>Pb>Ni>Cd>Co>Cr. Average total bioavailable (non-residual) fraction of the metals consisted of 52.0% of the metal load, with this fraction for Cd and Pb being 73.9% and 60.7% respectively. Topsoils around the dumpsite were evidently polluted with high levels of copper and lead. Seepage of leachate from the dumpsite has the potential of contaminating ground water reserves. Improper disposal of industrial solid wastes appears to be the likely source of metal pollution in the industrial estate. Heavy metal pollution in the estate can therefore be significantly reduced by prompt and proper disposal of generated solid wastes, and the application of particulate scrubbers in the industries.
文摘It has been observed that the portable water quality obtained from various locations in Kano Metropolis has shown greater variations in the recent past. Attempts have been made to ascertain the reasons for the variations even though the supplies were from only two treatments plants that obtain their raw water from the same source. A total of 92 water samples comprising of raw (from plants) and treated (from the plants and taps) were collected during rainy and dry seasons between April 2010 and May, 2012 and analyzed using standard analytical techniques. The results of analysis gave the physiochemical properties with range as follows: pH (0.06 ± 6.7 - 6.04 ± 0.02) conductivity (7.23 ±0.04 - 13.33 ± 0.22 S/Cm), turbidity (5.00 ± 0.01 - 449.22 ±1.32 NTU), suspended solids (107.33±3.45 - 712.11 ±5.33 mg/dm3), total dissolved solids (18.50 ± 0.85 -186 .78 ± 2.48 mg/dm3 ), alkalinity (12.53± 0.32 - 80.75 ± 1.23 mg/dm3) and hardness (29.50 ± 1.22 - 58.67 ± 2.34 mg/dm3). The pH values were generally acidic while the turbidity and total solid especially in some locations were higher than the permissible levels set by the World Health Organization for portable water. The concentration of heavy metals (mg/dm3) were found in the following ranges Fe (0.10 ± 0.04 - 0.30 ± 0.02), Cu (0.01 ± 0.001 - 0.03 ± 0.002), Zn (0.13 ± 0.06 - 0.39 ±0.02), Pb (0.03 ± 0.01 - 0.17 ± 0.02), Mn (0.03 ± 0.004 - 0.13 ± 0.003), Cr (0.10 ± 0.04 - 0.31 ± 0.03). The highest values of Fe, Cu and Mn were recorded along the older distribution channel of Challawa. The levels of Pb and Cr were generally high in both routes which are also observed in the raw water used at the two treatments plants. The results obtained from heavy metal concentrations fell within the maximum allowable limit set by the World Health Organization for portable water except in the cases of Pb and Cr. The high Fe, Mn, Cu levels as obtained in the Challawa route were attributed to leaching from rusting in the old galvanized metal pipe-work in the distribution channel. The levels of chromium and lead were similar in the two networks showing that the raw water used in the both treatment plants were responsible for the high values obtained and were not effectively removed by the treatment processes.