Monday, August 5, 2019

Effects Of Barapukuria Coal Mining On Environment Environmental Sciences Essay

Effects Of Barapukuria Coal Mining On Environment Environmental Sciences Essay The over increasing gap between supply of and energy is problem for many countries around the world. Governments are forced to examine different sources of energy in an attempt to create secure energy supply. The results of these examinations cover a large range of energy sources, not only traditional ones such as oil and gas, also nuclear-power and renewable resources. In addition governments are looking at increasing energy efficiency Because of the pressing need; there has also been a strategic shift in some countries back to using traditional fossil fuels. This has become more prevalent and widespread in developing countries where coal is the most dominant of traditional options used. There are two key reasons for this choice: first, there is abundant supply of coal; it is one of the cheapest ways to create electricity (Jaccard, 2005). The resurgence coal as an energy source may come as a shock to some because of environmental impacts it has had in the past .However, some countries that have remained dependent on coal for energy, such as the United States, have mitigated the environmental impacts with new technologies stringent regulation. The economic development of the country requires different types of fuels and energy. Because of deforestation, supply of traditional fuels are decreasing and becoming expensive day by day. Significant portion of export earning is being used for import of petroleum products and coal (Hamilton 2005). The key to creating reliable sources of energy is diversification. Since there are significant reserves of coal located in the northwest region of the country, and a belief within industry that further exploration may lead to the discovery of additional coal fields, this is a source of energy to consider. However turning to coal brings important concerns of policy makers, particularly about how to balance coal development with environmental concerns. The total national reserves of coal in 5 coal fields are estimated about 2.9 billion metric tons. Recovery rate of coal from reserves depends on the availability of technology and method of mining. Modern mining technology can ensure up to 85% recovery of coal from different reserves (Hamilton, 2005). Coal is a very important but dirty fossil fuel. Coal mining has severe environmental, ecological, human-health consequences. If not done properly, coal mining has potential to damage landscape, soils, surface water, groundwater, air during all phases of exploration and use. Coal mining has some unavoidable negative impacts on humans and the environment. In its review of the mining industry of Bangladesh, the U.S. Geological Survey states that the country has small reserves of coal, natural gas, and petroleum. In May 2011, the countrys overall coal production was around 3,000 tons a day, from the lone operational state-owned Barapukuria coal mine in Dinajpur. There are five coal field discovered such as Khalashpeer, Rangpur (1995) coal field depth at 257-483 meter which is about 12 Km2 in area and proven reserve coal is 143 (GSB), 685 (Hosaf) in million tones. Phulbari, Dinajpur (1997) coal field which is about30 Km2 in area and depth at 150-240 meter and reserve coal is 572 million t ones. Jamal gong, Jaipurhat (1965) coal field which is about 16 Km2 in area and depth at 900-1000 meter and proven reserve coal is about 1050 million tones .Dighirpar, Dinajpur (1995) coal field is at 327 meter depth and area not yet to known and reserve coal is about 200 (partly evaluated) million tones. The major findings were as under about Barapukuria, Dinajpur Coal Field Reserve of coal 390 Million tones, Depth of coal is 118-509 meter, Nos. of coal layer is 6, Average thickness of coal seam is 36 m, Composition of coal: ash 12.4%, Sulphur 0.53%, Moisture 10%, Rank of coal is Bituminous (high volatile), Calorific value of coal is 25.68 MJ/KG (11040 BTU/lb), Yearly Production is 1 million tones, Coal extraction method is Multi-Slice Long wall, During development of Barapukuria Coal Mine as well as load testing /trial run , coal as obtained from the mine, on the chemical analysis, confirmed composition of coal, Rank of coal and Calorific value of coal as predicted (Petrobangla, G ovt. Bangladesh, 2005). The state-owned company, Bangladesh Oil, Gas and Mineral Corporation, which is commonly known as Petrobangla, is involved in oil and gas exploration, production, and distribution. It is also involved in the exploration for and production of such minerals as coal, granite, and limestone for the manufacture of cement. Nearly half the Bangladeshi population is food insecure, and nearly one quarter severely food insecure. Local food production should be strengthened, not sacrificed for industrial projects, said the Special Rapporteur on the right to food, Olivier De Schutter. The land under threat is located in Bangladeshs most fertile agricultural region where production of staple crops such as rice and wheat allows subsistence farmers to feed their families, and supports the entire countrys food needs. In addition to the destruction of agricultural land, waterways supporting over 1,000 fisheries and nearly 50,000 fruit trees may be destroyed. The water table may be lowered by 15-25 met ers over the life span of the mine. Access to safe drinking water for some 220,000 people is at stake, stated Catarina de Albuquerque, the Special Rapporteur on the human right to safe drinking water and sanitation. The mine would cause noise and dust pollution through dynamite explosion. Coal dust will pollute the air. Water will be polluted from washing the coal, risking pollution of surrounding water bodies. Bangladesh has networks of hundreds of small rivers, meaning that water pollution in one area can spread over a large area (Petrobangla, Govt. Bangladesh, 2005). To prevent the mine from flooding, huge pumps would run 24 hours a day for the 30 years of the mining project, pumping up to 800 million liters of water a day out of the mine. Groundwater in an area covering about 500 square kilometers would be lowered. Wells would no longer provide enough water for farmers. Asia Energys solution is to distribute the water pumped out to farmers. Once the mining is finished, Asia Energy plans to create a huge lake, providing fresh water, fisheries and recreation, according to the company. But after 30 years of digging, the water will be toxic. As the civilization has advanced tremendously over the last century, the alternative source of power generation came in effect like nuclear power, which certainly replaced coal in the west. Assessing the coalmine and its versatile impact over the industrial revolution time, the researcher, end of the 20th century revealed that there is huge risk of health, potential air pollution, noticeable change in landscape, political and social problem, overall sustainability of the environment could get seriously affected by coal mine operation. Therefore, it is obvious that an assessment of the local environment should go prior and along the project of Barapukuria before any unexpected consequence over whelms this project. Energy is vital element of our daily lives, no matter where one lives (Petrobangla, Govt. Bangladesh, 2005). Regionally, the Barapukuria coal basin is located in the Dinajpur Shield of Bangladesh and is surrounded by the Himalayan Fore deep to the north, the Shillong Shield/Platform to the east, and the Indian Peninsular Shield to the west. The geologic and structural conditions of the basin were illustrated in details by Islam and Hayashi (Khan, 1991; Khan and Chouhan, 1996; Alam et al., 2003; Islam and Hayashi, 2008a; Islam et al., 2009). Structurally, the Barapukuria basin is a long, narrow, and shallow Permo Carboniferous rift basin. The basin trends approximately north-south for over 5 km, ranges from 2 to 3 km wide, and is over 550 m deep. Below a prominent unconformity, covered by an unstructured Pleistocene through Tertiary classic sequence, steeply dipping normal faults bound tilted half graven fault blocks. The northern, western, and southern boundaries of the basin are also truncated by several small-scale normal boundary faults. The faults and igneous dyke decrease the cohesion and friction angle and reduce the shear strength through fault plane and filling materials. The overall structures of the Barapukuria Basin imply a tectonically active highly disturbed zone (Wardell Armstrong, 1991; Bakr et al., 1996; Islam, 2005; Islam and Hayashi, 2008a; Islam et al., 2009). The Barapukuria half-graven basin is assumed to be related to its tectonic origin. The basin area is very close (about 200 km) to the convergence boundary of the Indian and Eurasian plates. As a consequence, the far field tectonic stress field is highly significant to the structure of this basin. A 5 km long Eastern Boundary Fault of the Barapukuria basin is the best structural evidence for recent tectonic activity. However, the basin geometry and its stress field are directly related to the tectonic displacement gradient. Usually, the Barapukuria type intracrationic half graben basin in a convergent regime is developed due to local crustal weakening, where archeology strongly affects the dynamics of basin formation (Buck, 1991; Cloetingh et al., 1995). In a gross sense, for the Barapukuria type half graben basin, displacement is greatest at the center of the fault and decreases to zero at the fault tips. The displacement of an initially horizontal surface that intersects the fault is greatest at the fault itself and decreases with distance away from the fault . This produces footwall uplift and hanging wall subsidence, the later which creates the sedimentary basin (Gibson et al., 1989; Contreras et al., 1997). It is apparent that the basin geometry is affect-ted by fault propagation and displacement is accumulated on the boundary fault. About 200 m vertical displacement occurred with 73oC dipping. Along the basin the fault length is about 5 km. The fault length: vertical displacement ratio is about 25:1. About 60 m horizontal displacement indicates recent tectonic activity and the basin is developed due to 60 m horizontal displacement of the boundary fault towards the east (Islam et al., 2009). The objectives of the research were: To know the chemical properties of the of the coal, coal water and nearby agriculture field and To know that whether these chemical parameters are polluting the environment of the area or not. Chapter 2 Review of Literature Global Coal Management policy continued to wait for approval from the Government for its Barapukuria coal projects plan of development. The projects environmental impact and feasibility studies had been completed, and mining operations could be done by open pit method. After coal preparation, the final product would be coking coal and thermal coal for both export and domestic use. The bituminous coal resource of 572 million metric tons was large enough for the mine to last more than 30 years at a mining rate of 15 Mt/yr. There are major environmental issues in the mining of coal that include land disturbance, water pollution, and impacts on air quality (World Coal Institute, 2007). There are number of environmental issues linked to both underground and surface mining and they concerns mostly the impacts on water and air quality. First acid mine drainage (AMD). It is caused by the oxidation of pyretic sulphur due to exposure of pyrite (FeS2) to air and water, it can cause acidity (or a decrease in the pH of water) and subsequent elevated concentrations of metals that are associated with sulphide mineralogy (Management Brent, 2005). AMD causes contamination if it gets into the water system. A second environmental concern related to mining is the leaching of metals into the water in the area. AMD and leaching of metals result in fish dying and negatively impact the plant life in the water .A third concern is the emissions of particulates from the mining process that degrade air quality. The primary causes of these particulates are dust due to the movement of vehicles used at all stages of the mining process. A fourth concerns is methane. Methane is a potent greenhouse gas released from the coal seams. Technology has been developed that captures and uses methane for heating or electricity generations (The Coal Authority, 2007). As of 1994, the Ministry of Environment and Forest (MoEF) requires that Environmental Impact Assessments (EIA) be completed (Rajaram et al., 2005). These EIA consist of a two-stage clearance. First, a site clearance, followed by an environmental clearance. The complete process includes the following components: screening; scoping and consideration of alternatives; base line data collection ;impact prediction; assessment of alternatives; outlining of mitigation measures and an environmental impact statement; public hearings; environmental management plan; decision making; and monitoring (MoEF, 2001). In addition to conducting an EIA prior to operations, environmental statements must be submitted on an annual basis. Guidelines for reclamation activities are supplied under the EIA process, and reclamation is expected to proceed concurrently with mining operations. Although the planning of mine closure and reclamation is recognized as important, and thus should be incorporated into the mining plan, in India this is still at the embryonic stage (Rajaram et aI., 2005). The permission of the surface landowner must be sought prior to leasing of the subsurface minerals. There are two main options to obtain this consent: through written consent from the surface owner or a bond posted by the mine operator to cover any damages that might occur to the surface of the land (Hamilton, 2005). Evaluation of possible environmental impacts for Barapukuria thermal power plant and coal mine: In this study, an attempt was taken to conduct environmental impact assessment of Barapukuria thermal power and coal mining project through environmental, socio-economical and meteorological study. The analysis showed that, the Mn concentration was found in the satisfactory range. The pH was found slightly alkaline and surface water was bacteria contaminated. SO4 concentration was in the range of WHO standard. Calculated Sox loading was almost same of monitored emission. Corresponding estimated concentration of Sox was in acceptable range, which may not bring any matter of concern. In the study, an attempt was also made to evaluate the health impacts of SPM (suspended particulate matter) emitted from the combustion of coal in the power plant. The socio economic condition was also considered a dominating factor, for the EIA along with the chemical parameters since increased employment for t he project (Alam et al., 2011). Analysis of orientation of maximum horizontal tensional stress of the Gondwana Barapukuria coal basin, NW Bangladesh: By means of finite element modeling: This paper uses two-dimensional Finite Element Method (FEM) numerical modeling to analyze the orientation of maximum horizontal tensional stress of the Barapukuria coal basin in Bangladesh. An elastic plane stress model incorporating elastic rock physical properties for the coal basin area was used consisting of 2916 elements with a network of 1540 nodes (Md.Rafiqul Islam, 2009).The stress field at any point of the model is assumed to comprise gravitational and tectonic components. The tectonic component is assumed to act entirely in the horizontal plane in the far-field and at the model eastern boundary. Modeling results are presented in terms of four parameters, i.e. orientation of maximum horizontal tensional stress, displacement vector, strain distribution, and maximum shear stress contour line within the model. Results show th at the orientation of the maximum horizontal tensional stress axis is almost N45oE, which coincides with the regional stress field as studied by Gown et al. (1992). Coal mining impact on land use/land cover in jainta hills district of Meghalay, India using remote sensing and GIS technique: K. Sarma and S.P.S. Kushwaha conducted their study was undertaken to analyze the process of human-induced landscape transformation in the coal mined affected areas of Jaintia Hills district of Meghalaya, northeast India by interpreting temporal remote sensing data using geographic information system. The study revealed that most of the areas were dominated by grassland/non- forest in all the time sequence period of the study. Impact of surface coal mining on three Ohio watersheds ground water chemistry: Bonta et al. (1992) conducted a study to determine the effects of surface mining and reclamation on ground-water chemistry in three saturated zones in each of three small East Central Ohio water-sheds. The extensive disturbances of mining and reclamation: i) caused more changes in constituents concentration in the upper zone than the lower zone. Most of which were statistically significant increases, ii) affected ground-water chemistry in lower zones those that were not physically disturbed, iii) tented to increases the frequency of exceedance of regulated constituents in all saturated zones and (4) affected the chemistry of surface base flow water at the watershed outlets. Several constituents were still changing at the end of the project within all sites and zones (Anhaeusser and Maske, 1986). Mine-water chemistry: the good, the bad and the ugly: The mine discharged water and wastes for several times. They collected huge amount of water samples from different mine discharge and worked on them. They found that the discharged water could be useful sometimes but most of the times the nature is ugly (Banks, 1997). Trace elements emission factors from coal combustion: A research on increase in the mobilization of trace elements in the environment especially in the atmosphere. An accurate knowledge of factors related to the mobilization, particularly the enrichment mechanism of trace elements in the emitted particulate, is of fundamental significance for environmental impact assessment studies. In this work an analytical method is presented to calculate the trace element emission factors taking into account the enrichment of trace element (Cernuschi, 1987). Trace metals from coal-fired power plants: Derivation of an average data base for assessment studies of the situation in the European communities. The potential impact on different part of the ecosystem and man from the release of trace element from the coal fired power plants, they use twenty nine coal samples for their research, using the derived main values as well as taking into account of coal to be burnet in power plant of EC. The average trace element mobilization was predicted for fifteen elements for the year 1990, the global release so estimated range from 66.5 to 19,420 metric tons from Hg Zn, respectively (Sabbioni, 1983). Criteria for determining when a body of surface water constitutes a hazard to mining: Kendorsky et al. discussed that there are various criteria for determining the quality of surface water body. They worked hard in determining the water constituents that are exposed in mining activities (coal mining). The surface drainage (acid mine drainage, heavy metal contamination etc.) causes several environmental impact (Molinda, 1999). Various research work carried out on hydrogen ion concentration and nutrient status in soil: Soil pH varied widely from one soil series to another. Soil pH ranged from 4.32 to 7.64 in 0 15 cm depth and the soil pH ranged from 4.55 to 7.81 in 15 30 cm at Sonatala series (Huq, 2005). In dry season the soil pH of coastal areas of Bangladesh were recorded between 6.25 to 8.34 and in the wet season the soil pH of coastal areas were recorded between 5.74 to 7.96 respectively (Alam, 2004) The soil pH of Taras series under AEZ-5 ranged from 5.54 to 5.90 and the pH of Jaonia series were ranged from 4.82 to 6.09 under AEZ-6. Both of the series were in acidic in nature (Alam, 2005). The pH of the old Brahmaputra Floodplain soil ranged from 6.02 to 7.10 and that of Madhupur tract from 6.99 to 7.02 under different cropping patterns and tillage (Hossain et al., 2003).The optimum soil pH for crop production was considered to be between 6.5 to 7.0 (Tisdale et al., 1999). The pH of the soil class high land and medium high land under soil series Amnura was 4.2 to 5.7 and 4.7 to 6.3 respectively in upland which was acidic than wet land (SRDI, 1999). The soil pH of the high, medium high and medium low under Sathi upazila ranged from 7.4 to 7.9, 7.3 to 7.6 and 5.0 to 7.8 respectively (SRDI, 1992). The organic carbon content of soil at Sonatala series ranged from .58% to 1.08% in 0 to 15cm depth the organic carbon content of soil at the same series ranged from 0.58% to 0.89% in 15 to 30cm (Huq (2005). The organic matter content of soil of the Taras series under AEZ-5 ranged from 1.26% to 2.42% and the organic matter content in the Jaonia series were ranged from 1.68% to 2.52% under AEZ-6 (Alam, 2005). In the dry season the organic matter content of the coastal area of Bangladesh was recorded at the ranged between 0.29 to 1.08% and in the wet season the organic matter content in the same areas were ranged from 0.34 to 1.27% respectively (Alam, 2004). Organic matter values of the old Brahmaputra floodplain ranged from 0.64 to 1.77% and that of Madhupur tract from 0.21 to 1.69% under different cropping patterns and tillages (Hossain et al., 2003).The organic matter content of high land, medium high land and medium low land under Singra upazila values from 1.31%, 1.89% and 2.59% respectively (SRDI, 2001a). The organic matter content of high land, medium high land and medium low land under Madhupur upazila values from 2.45%, 1.24% and 2.31% respectively (SRDI, 2001a). The organic matter content in varied from 0.58 to 2.13% of BAU Agriculture farm and also found that the organic matter contents were relatively higher at the surface layer but decreased at soil depth (Mondol, 1998).The organic matter content varied from 0.79 to 2.35% in ten selected soil series of Bangladesh and also observed that the organic matter contents relatively higher at the surface but decreased at soil depth (Fakir, 1998).Present organic Carbon of some non- irrigated soils of Madhupur upazila ranged from 0.5 to 0.85% (Zaman and Nuruzzaman, 1995). The available P content ranged from 9.8 to 12.75ppm at 0-15cm in depth in Sonatala series and the same series the available P content ranged from 5.75 to 9.24ppm at the depth of 15 to 30cm (Huq, 2005). The available P content of the Taras series under AEZ- 5 ranged from 5.04 to 24.9 mg/kg and the available P content of the Jaonia series under AEZ- 6 ranged from 6.48 to 8.58 mg/kg (Alam, 2005). Available P values of the old Brahmaputra floodplain soil varied from 7.0 to 20.0 Â µgg-1 under different cropping patterns and tillages (Hossain et al., 2003). The available P content ranged from 6.7 to 10.4 mg/kg in Barkol series, 8.0 to 11.9 ppm in khadimnagar series, 9.6 to 13.2 ppm in Subalong series, 13.9 to 16.2 ppm in Tejgaon series, 16.2 to 17 ppm in Belabl series, 10.1 to 17.4 ppm in Sonatala series and 11.9 to 17 ppm in Silmondi series (Ahamed, 2002). The available P content of high land, medium high land and medium low land under Mymensingh Sadar upazila values from 32 Â µgg-1, 410 Â µgg-1 and 1150 Â µgg-1 respectively (SRDI, 2001a). The available P content of high land, medium high land and medium low land under Singra upazila values from 7.33, 7.20 and 60 Â µgg-1 respectively (SRDI, 2001a). Available P content of high land, medium high land and medium low land under Madhupur upazila values from 6, 5 and 8 Â µgg-1 respectively (SRDI, 2001a). The available P content of the non-irrigated surface sub surface soil of Ghatail and Kalihati upazila were 4 to 4.2 ppm and 2 to 26 ppm respectively (Razzaque et al., 1998) The P content of high land, medium high land and medium low land under Shahzadpur upazila values from 7 Â µgg-1, 9 Â µgg-1 and 6 Â µgg-1 soil, respectively (SRDI, 1997). Available P contents in Soan River valley soils of lower Shiwaliks of Himachal Pradesh were 2.0 to 29.0 mg Kg-1 (Kumar et al., 1995). The P content of high land, medium high and medium low land under Sathi upazila values from 34Â µgg-1, 34 Â µgg-1 and 17 Â µgg-1 soil, respectively (SRDI, 1992). The Exchangeable Potassium content ranged from 0.09 to 0.93me/l00gm soil at 0-15 cm depth in the Sonatala series and the same series the Exchangeable Potassium content ranged from 0.08 to 0.71me/l00gm soil at the depth of 15-30 cm (Huq, 2005). The Exchangeable K of the Taras series under AEZ-5 ranged from 0.14to 0.27cmol/kg soil and the Exchangeable K of Jaonia series were ranged 0.33to 0.50cmol/kg soil under AEZ-6 (Alam, 2005). In dry season, the potassium concentration of coastal area of Bangladesh were recorded at the ranged between 0.20 to 1.17me/l00g soil and in wet season the potassium concentration of the same areas were recorded at the ranged between 0.08 to 0.83me/ l00g soil respectively (Alam, 2004). The available K content of the Brahmaputra flood plain soil varied from 0.10 to 0.27meq 100-1 soil and that of Madhupur Tract soil from 0.10 to 0.21meq 100-1 soil under different cropping patterns tillages and depth (Hossain et al., 2003). The K content of high land, medium high land and medium low land under Singra upazila values from 0.27meq l00g-1 soil, 0.30meq l00g-1 soil, and 0.34meq l00 g-1 soil, respectively ( SRDI, 200la). The K content of high land, medium high land and medium low land under Madhupur upazila values from 0.21meq l00 g-1 soil, 0.13meq l00g-1 soil, and 0.16meq 100 g-1soil, respectively (SRDI, 200Ib).The K content of high land, medium high land and medium low land under Singra upazila values from 0.16meq l00g-1 soil, 0.19meq l00 g-1 soil, and 0.13meq l00g-1 soil, respectively (SRDI, 200Ic). The exchangeable K of old alluvial soils of some basin was 0.04 to 0.87meq l00g-1 soil (Singh et al., 2000). The series with high clay content required higher level of exchangeable K than a sandy soil to reach the same concentration of soil solution (Ray chaudhuri and Sanayl, 1999). An experiment on some soil properties and found that the water soluble K positively and significantly correlated with exchangeable K (Yadav et al., 1999). The available S content of the Taras series under AEZ-5 ranged from 16.8 to 17.8 mg/kg and the available S content of Jaonia series were ranged from 12.8 to 19.8 mg/kg under AEZ-6 (Alam, 2005). The available S ranged from 4.20 to 33.9 ppm at 0-15 cm depth in the Sonatala series and the same series the available S content ranged from 1.30 to 30.70 ppm at the depth of 15-30 cm (Huq, 2005). The available Sulphur (S) of soil decrease with increasing the depth of soils. The available S of the Old Brahmaputra Floodplain soil varied from 4.00 to 20.00 Â µgg-1 (Hossain et al., 2003). A laboratory experiment conducted on selected ten soil I series and reported that the available S of Barkol, Khadimnagar, Subalong, Tejgaon and Belabo series ranged from 12.11 tol3.39 ppm, 11.55 to 13.85 ppm, 13.00 to 15.76 ppm (Ahamed, 2002).The S content of high land, medium high land and medium low land under Mymensingh upazila values from 16Â µgg-1, 16 Â µgg-1and 13 Â µgg-1 soil, respectively (SRDI, 200Ic). The S status of the non-irrigated surface and sub-surface soils of Ghatail and Kalihati upazila were 2.5 to 47.5 and 2.0 to 30.00 mg/kg, respectively (Razzaque et al., 1998). The S content of high land, medium high land and medium low land under Shahzadpur upazila values from 13Â µgg-1, 23 Â µgg-1 and 7 Â µgg-1 soil respectively (SRDI, 1992). The Exchangeable Ca2+ content ranged from 5.74 to 8.23me/l00gm soil at 0-15 cm depth in the Sonatala series and the same series the Exchangeable Ca2+ content ranged from 4.13 to 6.16 me/l00gm soil at the depth of 15-30 cm (Huq, 2005). The Exchangeable Ca content of the Taras series under AEZ-5 ranged from 5.50 to 14.7cmol/kg soil and the Exchangeable Ca content of Jaonia series were ranged 12.7 to 14.0cmol/kg soil respectively under AEZ-6 (Alam, 2005). The exchangeable Ca content of higher land, medium high land and medium low land under Singra upazila values from 10.20meq l00g1, 15.21meq l00gl and 19.41meq 100g! soil, respectively (SRDI, 200la). The exchangeable Ca content of higher land, medium high land and medium low land under Madhupur upazila values from 0.8meq l00/g, 1.3meq l00/g and 1.3meq l00/g soil, respectively(SRDI, 2001b). The Ca content in non-irrigated surface and sub-surface soil of Ghatail and Kalihati upazila were 1.34 to 6.66meq l00/g and 1.9 to 5.62meq l00/g soil, respectively (Razzaque et al., 1998). Available calcium (Ca) content in some non-irrigated soils of Madhupur ranged from 0.37 to 3.73meq l00/g soil and the mean value was 2.52meq l00/g soil (Zaman and Nuruzzaman, 1995). The cation such as Ca2+ and Mg2+ at the concentrations of 0.68 to 1.98meq l00/g and 0.62 to 3.45meq l00/g soil, respectively (Matin and Anwar, 1994). Exchangeable Mg content in the non irrigated surface and sub surface soils of Ghatail and Kalihati Thana were 0.53-1.35 and 0.5-1.16emol/kg respectively. Portch and Islam (1984) reported that 21% soils of Bangladesh contain Mg below critical level and 25% below optimum level (Razzaque, 1995). Sewage sludge containing domestic wastes can have significant amount of Zn and Cu. The accumulation of Zn was found to affect microbial pollution in soils (McGrath et al., 1995). The range of available Zn content in some non-irrigated soils of Madhupur was 1.05-3.57 Â µgg-1and the mean value was 1.94Â µgg-1 (Zaman and Nuruzzaman, 1995). The Fe status of some soils of Rajasthan (Udaipur district) was 1.32-20.5 ppm (Mehra, 1994). An observed that 8% soils of Bangladesh contain Fe below optimum level (Porch and Islam, 1984). A general and specific investigation conducted across China soil and crop heavy metal contamination. He investigated Cd level in soil in contaminated areas throughout 15 provinces of the country. The results indicated that levels of Ch, Hg and Pb in soils were greater than the governmental standards. Cadmium ranged from 0.45 to 1.04 g/kg on average in the four cities and was as high as 145 mg/kg in soil (Wang et al., 2001). An experiment conducted on the status of separate components of natural ecosystems in the impact zone of the Nizhnekamsk industrial complex in the Tatar Republic, Russia. It was found that the contents of heavy metals in soils and plants of the impact zone were low. However, negative effect of heavy metals on the growth of lichens was observed. Changes in the degree of moistening of the study the Nizhnekamsk industrial complex have resulted in the transformation of the plant cover structure (Changes in species composition of the grass dwarf shrub later, appearance of hygrophytes, increasing role of mesohydrophytes in the phytocenosis, and the decay of trees) and in changes of population characteristics of common red backed vole (Morozkin et al., 2001). The total and available Pb concentrations of road dusts at city areas varied from 57.7 to 212 mg/kg and 0.030 to 2.03 mg/kg but from rural areas 6.2-1.7 mg/kg and 0.02-0.06 mg/kg, respectively. Usually, low Pb was observed from rural areas (Sattar and Blume, 1999). An studied on 30 soil samples from different parent materials in Bangladesh to determine the usual range of the quantities of trace elements and reported that DTPA extractable copper and iron ranged from1.0 to 14.2 mg/kg and 7 to 296 mg/k

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