|Title of Invention||
METHOD OF DETERMINING THE ACTUAL CONTRIBUTION OF AIR POLLUTANTS DUE TO OPENCAST COAL MINES
|Abstract||Mining operations in general have adverse impact on air quality. The emphasis on large-scale mechanization of surface mining has resulted in widespread concern about the deterioration of air quality within and around mining site. Every mine in India has to obtain environmental clearance from the Ministry of Environment and Forests (MOEF), Govt. of India. An Environmental Assessment (EIA) report is to be formulated for getting clearance form MOEF. Air pollution is considered to be the most important parameter in an EIA report. However there is no well-defined EIA methodology for evaluating the actual contribution of air pollutants due to a mining project by omitting the impact of air pollutants form the surrounding industries. Opencast coal mining is more severe in creating air pollution problem in comparison to underground mining. To maintain the energy demand, opencast mining has grown at a phenomenon rate in India. So it is essential to pay attention to assess the impacts on air environment due to mining activities. No systematic studies have been reported in India in this line and the objective of this invention is to work out a methodology to evaluate the actual contribution of air pollutants, which ultimately increases the level of air pollution in the area. The study area is also being polluted by the surrounding industrial activities. To evaluate the actual contribution of air pollutants emitted by the project in question; factal analysis technique based on the changes in climatological conditions has been developed. Approach to the selection of air monitoring stations and methods adopted for air quality survey for factal analysis is given. Four season data are generated and they are critically analyzed on the basis of dominant wind directions at different seasons Factal analysis technique has been developed and the concept has been applied to a large working mine at Jharia Coalfield.. Actual contribution of pollutants due to opencast mining is estimated by factal analysis technique based on the changes of the wind directions, and air quality at the monitoring stations when they are upwind and downwind from the mine The methodology adopted has formed a guideline to assess the impacts due to such projects, and can be utilized on an industrial scale at various sites.|
|Full Text||1.0 Field of invention
This invention relates to a noble method of determining the actual contribution of air pollutants due to mining, which ultimately increases the air pollution level in mining areas. 2.0 Back ground of invention
Demand of coal as the major source of energy and for the metallurgical purpose is increasing day by day. The energy policy of the country lays adequate emphasis on the exploitation of indigenously available coal resources. The national plan envisages further exploitation of coal resources at a tremendously rapid rate, which subsequently pose greater environmental problem. Underground mining is less detrimental with respect to opencast mining. To maintain the energy demand and over all coal production, opencast mining has grown at a phenomenal rate. Indian coal production, which is in the order of 320Mt/y, is currently supporting some 70,000 MW of thermal power generation, and with further developments being planned for 2010AD, this quantum of power generation is expected to increase to 150,000MW. A developing country like India must continue to promote industrial development if it is to achieve its target of establishing 150,000MW-power generation capacity by 2010AD. This will require increased mineral fuel production. More specifically, to meet its proposed energy needs, India must produce nearly double the quantity of coal it is mining at present, as its needs for the fuel will be in the range 550 Mt/y by 2010 AD
Surface mining operations can result in release of participate and gases towards atmosphere. Impact on air pollution due to opencast mining is tremendous. The environmental implications of fast growing OCPs are much more in case of dust. Due to various problems some amount of technology shifts in favor of opencast mining. In opencast mining a massive overburden will have to be removed to reach the mineral deposits. This may require excavators, transporters, loaders, conveyor belts etc., which will result in massive discharge of fine particulate from the overburden material. Similarly normal operation will require excavation, size reduction, waste separation, transportation, loading, stock pilling, retrieval, etc. AH will release paniculate matters. Closer operation is also similar to opening but for a short period. In mining areas spontaneous combustion of carbonaceous matter contained in the waste rock dumps results in polluting the atmosphere with smoke, noxious and hazardous gases. Gaseous pollutants are also released from the exhausts of HEMM and other vehicles used in mining areas. Since further plans envisages larger shave of opencast mining in over all production, the air quality in the mining areas will be worsen day-by-day if proper abatement measure is not taken.
Generally speaking strip mine air pollution sources can be divided into point sources, area sources and line sources. Point sources typically include stationary exhaust stacks. In contrast, there are particulates that emanate from the fugitive sources, such as large open spaces. During dry and windy conditions, the surface soil will be scavenged by the action of wind, causing particulate matter to be suspended in the atmosphere and transported to down wind as fugitive particulate emissions. In opencast mining area line and mobile sources also play an important role in air pollution. The exhausts from trucks would be considered as a mobile source of pollutant emission. If a number of trucks pass away the same road at short intervals of time, then the source may be treated as line source. Another way also, dust generated by the truck tiers could also be considered as a mobile fugitive sources. Thus, opencast mining cannot be only considered as a point source, rather it includes multisource of emission. Being a significant source of air pollution its air quality impact assessment is very essential. But at present no such study has been reported, so that air quality impact analysis due to coal mining can be done easily. The purpose and objectives of this work are to evaluate the status of air pollution, to develop a factal analysis technique to assess the actual contribution of air pollutants and their impacts in the surrounding lacerations. 3.0 Drawback associated with the known art
Opencast coal mining creates much more environmental pollution particularly air quality deterioration in respect of dust and gaseous pollutants in comparison to underground mining. It creates air pollution problem not only within the mining premises but also in the surrounding locations. But due to various problems in underground mining some amount of technology shifts in favor of opencast mining. To maintain the energy demand and overall coal production opencast mining has grown at a phenomenal rate in India. By 2000 AD, the coal production from opencast mining rose to 250 Mt, which was about 70% of total coal production. The increasing trend of opencast mining along with adaptation of large-scale mechanization leads to release huge amount of dust and gaseous pollutants, which will affect the ambient air quality more severely.
Environment as we know is of vital importance for the survival of human beings. Over exploitation of nature in the name of industrialization and development is causing degradation to our environment. At the same time, we do realize that, we cannot stop the development in the name of saving environment. A right kind of balance between sustainable development and environmental management is the need of the hour. Thus it is necessary to assess the impacts on air environment due to opencast coal mining so that proper mitigation measures could be implemented. Environmental impact assessment (EIA) plays a crucial role
• in resolving the conflicts .It is considered to be a valuable planning and decision making tool for prediction, evaluation and sound environmental management.
A search into technical literature available in the subject reveals that no systematic studies have been carried out to evaluate the impact on air quality and development of pollutant dispersion models for coal mining areas. The value of emission factor data and the coefficient of mathematical models have been developed to evaluate the air quality impact due to opencast mines in a number of countries abroad. But such studies have not been reported in India context. The technology and methodology developed in other countries has its limitation in Indian condition due to difference in climatic conditions, the method of mining, geological and gemorphological setting of the area. A few studies have been made in India for development of dispersion models due to stack emission, i.e., point source model for the prediction of air pollution levels. Opencast mines cannot be considered as a point source of emission. These are multisource of emission. No study has yet been reported for the development of pollutant dispersion models in minefields in India to assess the actual contribution of air pollutants and their impact in the surrounding locations.
The main air pollution problem in mining project area is due to the particulate matters. Particulate are non-gaseous substances consisting of dusts, other solids and vapor bubbles, liquids floating in the air and almost acting as gaseous molecules in may respects. Particulate react and damage mechanisms one is the chemical reaction with the molecules of respiratory system and bringing about adverse chemical changes. From this it may reduce the lung capacity in humans. The second mechanism by which these react is obstructive or interfering in nature without any chemical reaction. For example, the deposits of the particulate on the leaf may interfere or obstruct the sunlight falling on the leaf. Similarly the thinner particulate may react with the deposit in the human lung or animal lung interfering with their normal functions. In human lung, it may take the form of lung disease or nonspecific functional changes. These may be asthma, bronchitis or reduction of lung capacities. If there is a chemical reaction of the minerals, it may bring about silicosis and pneumoconiosis. If contains things like hydrocarbons etc. it may also bring fatal disease like cancer. Particulate by covering the leaves surfaces and plugging the stomata reduce the adsorption of CO2 from atmosphere and the intensity of the sunlight and thus suppress the photosynthesis and growth of plants. It reduces the visibility by the absorption and scattering solid and the liquid droplets.
Air pollution data revealed that compared to international standard, it has been deteriorated to unacceptable levels, and there is no epidemiological data available to correlate
the air quality, with general population. But it can be stated that based on data available there would be considerable health problems caused by air pollution, especially when poverty and malnutrition are so remnant in the area. Accumulation of dust on roadways causes considerable damage to plants and vegetation. There is almost no data available on these. How much agricultural products are affected by air pollution in India is yet to be determined and the figures can be staggering. Whenever vegetation is affected it would automatically cause adverse impact on inhabitants. Wild life, birds, animals, insects all many be affected in different degrees depending on their sensitivities or change in their food availability. Plenty of data are available in other countries with respect to the change in wild life population and distribution caused by air pollution. Wild life in India could also be affected in the same manner.
As the study area is also being polluted by the surrounding industrial activities, the objective of this study is to evaluate the actual contribution of pollutants on the air environment, their dispersion characteristics and impacts in the surrounding locations. But there is no well-defined guideline to evaluate such impacts. In this study attempts have been made to develop a factal analysis technique to assess the actual contribution of air pollutants and their impacts in the surrounding lacerations 4.0 Object of invention
The object of the invention is to develop a method to assess the impact of mining to increase the level of due to mining activities, which is an essential requirement for the preparation of an Environmental Impact Assessment (EIA) Report for getting clearance from the Government of India. EIA plays a crucial role in resolving the conflicts between developmental objectives and concern for the environmental quality. In fact EIA is considered to be a valuable planning and decision-making tool for prediction and evaluation. The methodology is based on three basic steps of environmental impact assessment, vis-a-vis identification, prediction and evaluation. Awareness regarding EIA in India has assumed a greater dimension particularly in the past few years. This has led to the preparation of EMP report prior to the implementation of any project for getting clearance from MOEF. This is required as a means of source of environmental management from early stages of developmental planning, minimizing the negative impacts to a level as low as possible.
The system of preparing EMP has been accepted as a statutory requirement for getting clearance from Department of Environment (DOEn), Govt. of India. All such mining projects need to be cleared by DOEn, MOEF, to ensure the effective safeguard at the designing stage against the environmental hazards. DOEn has issued guidelines for preparation of EMP
report for mining projects. Finally Environmental Appraisal Committee (EAC) for mining projects examines the report before giving any clearance to the project.
Air pollution is one of the important parameters to be considered in preparing an EIA, But there is no well-defined method of predicting the generation of air pollutants due to different mining activities. Emission factors reported by some authors for mining projects are not based on scientific reasoning. More over the pollutants emitted, all are not dispersed in the atmosphere. Nature has got some assimilative capacity to depollute and it varies from place to place depending on climate and other site-specific conditions. In short it is a very complex understanding and models are to be used for determining the assimilative capacity of the nature. For an accurate air quality impact assessment and to develop air pollutant dispersion models to evaluate the impacts in the surrounding locations, a well-guided research is essential. EIA reports prepared for mining projects in India for getting clearance from MOEF and the predictions made for air pollution level are not found to be accurate. Accordingly the control measures suggested for the mitigation of air pollution problem are also not found to be effective. It indicates that the predictions and control technology are not based on scientific study. The objective of this research is defined as follows:
Assessment of actual contribution of air pollutants due to a mining project in question and evaluation of the impact on air quality by increasing the air pollution level. 4.0 A summary of invention
Factal analysis is a technique to evaluate the actual contribution of air pollutants due to the activities of a project in question, excluding the background concentration of pollutants. Impacts on ambient air quality depend on the micrometeorological conditions specially wind velocity and wind direction Wind direction changes from season to season and responsible for carrying the air pollutants generated at the downwind locations. Fatal analysis technique based on climatological conditions was adopted. The complete specification for the air quality impact assessment methodology is given below:
An opencast project is to be identified to assess the impact on air environment due to its mining activities. It's geographical location, wind rose diagram of the area, climatological conditions are to be monitored.
ii) Ambient air monitoring stations are to be selected on the basis of dominant wind directions of the project area. Dominant wind directions in the area are to be ascertained from the wind rose diagram developed at the nearby meteorological station for that area. Let these be W and NW. Thus one
ambient air monitoring station is to be located at the centre of the project area. The approach is to put two monitoring instruments at upwind (W and NW) and two instruments at the downwind (E and SE) directions. From the project. The concentration value of the air pollutants at the upwind location will represent the background concentration of the pollutants.
iii) During the selection of ambient air monitoring stations, the approach is also to be to place the stations in industrial, residential and sensitive areas like hospital to discover the impact on the air environment in those areas because Central Pollution Control Board (CPCB) in various areas has fixed different standards. The distance of air monitoring stations from coal mining complex is dependant on the site-specific conditions. These are to be taken into consideration while studying dispersion characteristics of the pollutants.
iv) Thus, one station (say BA1) is to be set at the centre of the project. One ambient air monitoring station (say BA3) is to be selected at the west direction and another at the east direction (say BA2) from the centre of the project. So, the air pollution level at BA3 represents the upwind (background) concentration and at air pollution level BA2 represents the downwind concentration of the pollutants Another station BA4 is to be selected at the SE direction, which represents the upwind concentration and the other BA5 at NW direction from the centre of the project represents the upwind concentration of pollutants. The relative positions of these air monitoring stations are also to be identified with respect to industrial zone, residential zone and sensitive zone.
v) Ambient air samples are to be collected for four seasons, namely summer, monsoon, post monsoon and winter seasons in a year. The samples are to be collected for 48 hours duration in a week, for four weeks in each season. Samples are to be collected on 8 hourly basis for 24 hours duration in three shifts, daytime (6-14 hours), evening time (14-22 hours) and nighttime (22-6 hours) Micrometeorological data are also to be recorded on monitoring days.
vi) Air pollutants like suspended paniculate matter (SPM), respirable particulate matter (PM10), sulphur dioxide (SO2) and oxides of nitrogen (NOx) are to be collected with the help of high volume air sampler with respirable dust collector system (RDS) and are to be analyzed as per standard methods.
vii) Wind rose diagrams are to be plotted on the basis of micrometeorological data
collected on monitoring days for each season. The dominant wind directions tend to change in different seasons. The relative positions of the upwind and downwind locations of air pollution monitors are to be considered on the basis of the dominant wind direction as shown in the wind rose diagrams developed for that particular season.
viii) Factal analysis technique is to be adopted to evaluate the actual contribution of air pollutants by a project in question and by the surrounding industries. The assessment of actual contribution (impact) of air pollutants due to the project activities is to be computed by deducting the upwind concentration of pollutants from down wind concentration of pollutants obtained at the cente of the project.
5.1 Description of the study area
Jharia Coalfield (JCF) is one of the most important coalfields as the Indian reserve of coking coal is main located in this area . It is situated in the heart of Damodar Valley, mainly along the north of this river and covers an area over 460 sq. km. Coal exploration started intensively in 1925 and soon after its exploration it gained its pre-eminent position because it was the main producer of prime coking coal. Coal Council of India estimated the reserve up to 1219m depths is 19339 Mt. This coalfield is divided into 14 areas and it is having a cluster of coal mines. It accounts for more than 30% of the total Indian Coal production. The indigenous coking coal production in India presently is not fulfilling the demand. The extraction of coking coal is increasing in a rapid rate to meet the demand and to reduce the import by expanding opencast mines. The project under study is one of the largest opencast projects (OCP) for coking coal owned by Bharat Coking Coal Ltd. (BCCL) in JCF. It had 34.6 Mt of quarriable reserve of coal and targeted production of 2.5 Mt/y and the life of the project was about 17 years. The summarized data of the project are shown in Table 1. For different mining operation purposes heavy earth moving machines (HEMM) including dragline were utilized. These machines generate a lot of dusts during their operations. The project is located between latitudes 23°46'30" and 23°47'40"N and between longitudes 86° 10'47 and 86°13'31"E and covers an area of about 6.8 sq. km. . The region has a tropical type monsoon climate. The temperature experienced between 4 to 48°C and average annual rainfall is 1197 mm.
Table 1 Summarized data of the OCP
1. Geological reserves Mt. 36.7
(Considered for the project)
2. Mineable reserves Mt. 34.8
3. Target output per year Mt. 2.5
4. Project started -- 1983-84
5. Project life Y 17
6. Maximum depth m 220
7. Av. stripping ratio m3/t 4.88
8. Total overburden Mm3 170.38
9. Land sanctioned ha 673.5
10. Working seam X seam (9.62mthick)
11. Av. quality of coal grade W-IV
12. Working depth of seam m 75 in dragline section
60 in box cut 3 sec.
13. Dip of the seam 1 in 6 in dragline section
1 in 7 in box cut 3 section
14. Av. stripping ratio m3/t Power shovel, drag-
line, drill m/c, dumper, scraper, dozer, feeder breaker etc.
5.2Data collection methods
As the project is surrounded by a number of coal mines and their allied activities it is essential to know the background air pollution level to assess the actual contribution of pollutants by this project. In the present context, attempts had been made by monitoring of air pollution at upwind and downwind sampling locations with in the coal mining complex. Plumes transported to downwind directions, as such placing a sampler immediately upwind and downwind locations of the project can measure pollutants emanating from OCP. The upwind sampler measures the background concentration of the pollutants of interest and the downwind sampler measures the impacts due to the dispersion of the pollutants.
Simultaneously, an identical sampler located at the centre of the project measures the total concentration of pollutant emanating from the project and background. The difference in concentration of pollutants between the central and upwind (background) measurements may be considered as the actual contribution of pollutants by the project activities in question. And the difference between the central and downwind measurements may be considered as the impacts of the project activities in the surrounding locations out side the mine and the dispersion characteristics of the pollutants.
Ambient air monitoring stations were selected keeping in view of the dominant wind directions prevailed in the area. Ghose and Banerjee reported the dominant wind directions of the area as W and NW as observed from 30 years average data of Dhanbad meteorological station. Thus one monitoring station, BA1 was located at the centre of the OCP. Two stations, BA3 and BA5 at upwind (W and NW) and two stations, BA2 and BA4 at downwind (E & SE) were located. So the concentration value at BA2 and BA4 represents downwind concentration and at BA3 and BA5 it shows upwind concentration with respect to BA1 for most of the time period. The approach was also to see that these should cover the industrial, residential and sensitive areas like hospital to assess the impact in these particular areas as different air quality standards have been laid down by Central Pollution Control Board (CPCB), Govt. of India. The details of the ambient air monitoring stations are given in Table 2. By virtue of the relative positions of the ambient air monitoring stations, stations BA1 and BA2 come under industrial zone, BA3 and BA4 come under residential zone and BA5 comes under sensitive zone.
An air quality survey was carried out twice in a week covering the premonsoon (May-June), monsoon (August), post monsoon (October) and winter (January) periods for four weeks in each season. Ambient air samples were collected (Ghose and Banerjee 1997) each day for 24 h in three 8-h shifts, corresponding to daytime, evening time and nighttime. Micrometeorological conditions were recorded on the sampling days with respect to wind direction, wind velocity, humidity and temperature. For the collection of samples of suspended particulate matter (SPM), glass fiber ambient (GF/A) filter paper was used in a high volume sampler (HVS) and for respirable dust particulate matter (RPM) GF/A was used in respirable dust sampler (RDS) at a flow rate of 1.0 - 1.5 m3/min that allows the SPM to deposit on the filter paper . Particulate with size range of 0.1-100µm were collected by HVS. The cut-point diameter of RDS was less than 10µm. Both HVS and RDS were manufactured by M/S Envirotech Ltd. New Delhi.
Table 2-Locations of different ambient air monitoring stations
Stn No. Station site Nature of Direction Location
area from Block
BA1 Block IIOCP Industrial Centre On the roof top of the Block II
pit office which about 4m above the ground level
BA2 Benidih OCP Industrial E On the roof top of the survey
survey office office at about 4m above the
ground and 2km away from BA1
BA3 Nudkhurkee Residential W On the roof top of a villager's
house which about 7m above the ground and 2.5 km away from BAl
BA4 Madhuband Residential SE On the roof top of a villager's
house at about 3m above the ground and 2..5km away from BA1
BA5 Benidih Sensitive NW On the roof top of the hospital
hospital at about 4m above the ground
and 2km away fromBAl
HVS having impingers (bubbler trains) in series with sodium tetrachloromercurate as absorbing solution, were operated at an average flow rate of 0.5 1 /min.for collection of SO2 (as per IS: 5182, Part II 1969) for 24h.In case of collection of NOX, sodium hydroxide was used as absorbing solution and collected at an average flow rate of 0.5 1 /min for 24h (as per IS: 5182, Part IV 1976). The impinger samples were put in iceboxes immediately after sampling and transferred to a refrigerator until analyzed. These were analyzed spectrophotometrically using West and Gake methods and Jackob and Hochier modified methods for analysis of SO2 and NOx respectively. SPM and RPM were computed after weighing the filter paper before and after sampling. The filter paper was conditioned in a dry atmosphere before weighing.
The results of the ambient air quality at different sampling stations during different seasons are given in Table 3, which provides the status of air pollution observed during the year . The data of four seasons revealed that SPM concentration at almost all the monitoring stations exceeded the permissible limit specified by Central Pollution Control Board (CPCB) during winter, pre-monsoon and post monsoon periods. In fact, they exceeded the permissible limits specified for industrial (500 (µg/m3), residential (200 µg/m3) and hospital (100 µg/m3) areas. National ambient air quality standards are given in Table 4. During the monsoon period SPM fall within the permissible limit due to the removal of dust particulate with rainwater. RPM concentration in the industrial location (BA1) also exceeded the permissible limit (150 µg/m3). SO2 and NOx concentration were also found to exceed the permissible limit at different occasions. The annual rainfall was found to be 1622 mm. Wind rose diagrams at different seasons are shown in Figure 1. 6.0 A brief description of the accompanying drawing
During the winter dominant wind directions were from W and SW (Figure 1). In this season BA3 (W) represented the upwind location and BA2 (E) as downwind location with respect to BA1 (centre). The actual contribution of pollutants due to the OCP at BA1 was calculated by deducting the background concentration and these were found to be 422.32, 78.62,17.69, 1.48µ/m3 for SPM, RPM, SO2 and NOX respectively. The impacts due to the dispersion of pollutants at downwind location BA2 outside the mine were 654.17, 133.30,77.46,82.42 µg/m3 for SPM, RPM, SO2 and NOX respectively (Table 5). During summer dominant wind directions were from SW and W. In this season station BA3 (W) represented the upwind location and BA2 (E) represented the downwind location with respect to BA1 and the results shown in Table 5 represent the pollutant concentration at BA3 and BA1, the actual contribution of pollutants and the impacts due to the dispersion of pollutants at downwind location BA2. During monsoon dominant wind directions were from SE and E. In this season station BA4 (SE) represented the upwind location and BA5 (NW) represented the downwind location with respect to BA1. The results shown in Table 5 represent the pollutant concentration at BA4 and BA1, the actual contribution of pollutants and impacts due to he dispersion of pollutants at BA5. During post monsoon the dominant wind directions were from NW and SW. In this season station BA5 (NW) represented the upwind location and BA4 (SE) represented the downwind location with respect to BAl.The results shown in Table 5 represent in pollutant concentration at BA5 and BA1, the actual contribution of
Table 3 Ambient air quality at different sampling stations during different seasons
Winter Season Summer season Monsoon P
Sampling Range Mean S.D Range Mean S.D Range Mean S.D Range
SPM concentration in ?g/m3
BA1 765.6- 837.15 73.38 533.6- 593.87 53.16 297.8- 336.51 30.89 473.7-
986.9 650.3 392.6 585.1
BA2 552.7- 654.17 64.19 566.7- 618.97 47.17 158.1- 183.97 16.31 398.0-
754.5 709.0 211.9 295.8
BA3 380.9- 414.83 20.18 370.8- 398.79 18.99 93.0- 152.04 41.9 292.7-
451.5 423.2 212.0 367.8
BA4 246.8- 304.29 31.67 342.5- 414.95 57.04 86.7- 133.18 46.93 383.1-
342.7 493.1 212.3 488.6
BA5 207.8- 241.05 50.65 97.5- 118.76 21.32 73.8- 86.18 8.72 102.3-
265.6 157.8 96.0 211.7
RPM concentration in ?g/m3
BA1 155.8- 169.72 22.57 106.1- 119.50 12.69 55.7-77.6 66.74 7.55 89.0-117.9
BA2 110.8- 133.30 16.65 112.1- 127.02 12.27 30.3-46.0 37.17 4.51 85.8-108.5
BA3 80.8- 91.10 6.40 81.5-92.1 86.73 3.95 20.8-47.3 33.48 8.88 62.3-81.4
BA4 50.0-67.1 61.37 5.94 69.2-101.8 89.37 11.45 17.4-28.4 23.26 3.69 76.9-103.6
BA5 42.3-55.2 48.14 5.04 20.2-31.1 24.08 3.76 18.7-23.8 21.53 1.84 21.4-41.5
SO2 concentration in µg/m3
BA1 69.0-82.4 76.03 4.60 71.0- 101.38 15.59 36.3-70.0 60.91 10.68 69.9-105.3
BA2 60.0-88.5 77.46 8.12 67.9- 92.18 12.28 40.3-60.4 54.86 8..05 64.2-94.6
BA3 40.3-76.3 58.34 13.70 41.2- 70.24 17.42 30.1-61.5 43.85 10.14 46.0-84.7
BA4 38.2-78.1 62.80 13.54 74.6- 89.36 11.82 37.2-45.4 51.83 7.78 39.0-89.3
BA5 28.4-66.5 46.57 4.22 38.3-63.5 50.17 8.86 24.7-53.4 39.27 8.54 34.2-65,9
NOX concentration in µg/m3
BA1 49.8-64.2 57.46 4.40 32.8-68.7 70.77 10.38 31.6-44.2 41.25 4.55 45.0-56.1
pollutants and the impacts on air environment due to the opencast coal mining activities due to the dispersion of pollutants at BA4 Similarly the impacts on air quality at other locations also can be computed from the results as shown in Table 3.
*Annual arithmetic mean of minimum 104 measurements in a year taken twice a week 24 h
at uniform interval
**24 h /8 h values should be met 98 per cent of the time in a year. However 2 per cent of the
time, it may exceed but not two consecutive d.
Table 5 Factal analysis of the actual contribution of air pollutants due to mining
Season Air Upwind Central Contribution
pollutants concentration location by the project
(µg / m3) concentration µg/m3)
at BA3 at BAl at BAl
Winter SPM 414.83 837.15 422.32
RPM 91.10 169.72 71.62
SO2 58.34 76.03 17.69
NOX 58.98 57.46 1.48
at BA3 atBAl atBAl
Summer SPM 398.79 593.87 195.08
RPM 86.73 119.50 32.77
SO2 70.24 101.38 31.14
NOX 50.75 70.77 20.02
at BA4 at BAl at BAl
Monsoon SPM 133.18 336.51 198.33
RPM 23.26 66.74 43.48
SO2 51.83 60.91 9.08
NOX 37.88 41.25 3.37
at BA5 at BAl at BAl
Post SPM 152.73 525.43 372.70
RPM 30.68 100.91 70.23
SO2 51.83 80.08 35.17
NOX 42.29 50.88 8.59
This study adds the following recommendations to operators and regulators of
1. Pollution concentrations and wind directions should be monitored at several key positions around opencast mines.
2. Air quality at these monitoring stations when they are upwind from opencast mine
should be compared to estimate the pollution caused by the mine and other
industries in its vicinity.
3. Air quality at the stations when they are downwind from the mine should be
compared to estimate the impacts due to the dispersion of pollutants.
4. Pollution abatement efforts will be more accurate and effective if they attribute only
the pollution due to the mine.
5. Furthermore, mine officials should be made aware of the acceptable differences
between upwind and downwind concentrations with respect to mine and be forced
to change their procedures until these acceptable limits are achieved.
1. A method of determining the actual contribution of air pollutants due to opencast coal mining comprises the steps of selecting the air pollution monitoring stations, measuring, suspended particulate matter (SPM), respirable particulate matter (PM10), sulphur dioxide (SO2) and oxides of nitrogen (NOx) throughout a year, determination of wind velocity and direction and developing seasonal wind rose diagrams, and determination of the actual contribution of air pollutants with respect to the relative positions of the upwind (back ground) of the air pollution monitors from the centre by excluding the background load of pollutants .
2. Method as claimed in claim 1, wherein air pollution monitoring stations are selected
at opencast coal mine - one at the centre of the mine, others at the dominant wind
directions keeping in view of upwind (back ground) and downwind locations of
monitors from the central position of the mine to determine the status information of
air pollution load due to its mining activities.
3. Method as claimed in claim 1, wherein during the selection of monitoring stations, the
approach is also to place the stations in industrial, residential and sensitive areas like
hospital to determine the pollution load on the air environment in those areas
4. Method as claimed in claim 1, wherein air samples are collected for four seasons,
namely summer, monsoon, post monsoon and winter seasons in a year, the samplings
are continued for 48 hours duration in a week, for four weeks in each season, samples
are collected on 8 hourly basis for 24 hours duration in three shifts, daytime (6-14
hours), evening time (14-22 hours) and nighttime (22-6 hours), and the concentration
value of the air pollutants at the upwind location represents the background load of
5. Method as claimed in claim 4, wherein measurement of air pollutants is done based
on air samples collected with the help of high volume air sampler with respirable dust
collector system (RDS) and air pollutants like suspended particulate matter (SPM),
respirable particulate matter (PM10), sulphur dioxide (SO2) and oxides of nitrogen
(NOx) are determined, and status of air pollution load in the area is determined.
6. Method as claimed in claim 1, wherein wind velocity and direction are measured with
the help of wind vane anemometer, and wind rose diagrams are developed for
7. Method as described in claim 6, wherein wind rose diagrams indicate that the
dominant wind directions tend to change in different seasons and the relative positions
of the upwind and downwind locations of air pollution monitors are considered on the basis of the dominant wind direction as shown in the wind rose diagrams developed for that particular season.
8. Method as claimed in claim 1, wherein actual contribution of pollutants due to opencast mining is determined on the basis of the changes of the wind directions and the air pollution load at the monitoring stations when they are upwind (back ground) from the mine and excluding the background load of pollutants.
Mining operations in general have adverse impact on air quality. The emphasis on large-scale mechanization of surface mining has resulted in widespread concern about the deterioration of air quality within and around mining site. Every mine in India has to obtain environmental clearance from the Ministry of Environment and Forests (MOEF), Govt. of India. An Environmental Assessment (EIA) report is to be formulated for getting clearance form MOEF. Air pollution is considered to be the most important parameter in an EIA report. However there is no well-defined EIA methodology for evaluating the actual contribution of air pollutants due to a mining project by omitting the impact of air pollutants form the surrounding industries. Opencast coal mining is more severe in creating air pollution problem in comparison to underground mining. To maintain the energy demand, opencast mining has grown at a phenomenon rate in India. So it is essential to pay attention to assess the impacts on air environment due to mining activities. No systematic studies have been reported in India in this line and the objective of this invention is to work out a methodology to evaluate the actual contribution of air pollutants, which ultimately increases the level of air pollution in the area. The study area is also being polluted by the surrounding industrial activities. To evaluate the actual contribution of air pollutants emitted by the project in question; factal analysis technique based on the changes in climatological conditions has been developed. Approach to the selection of air monitoring stations and methods adopted for air quality survey for factal analysis is given. Four season data are generated and they are critically analyzed on the basis of dominant wind directions at different seasons Factal analysis technique has been developed and the concept has been applied to a large working mine at Jharia Coalfield.. Actual contribution of pollutants due to opencast mining is estimated by factal analysis technique based on the changes of the wind directions, and air quality at the monitoring stations when they are upwind and downwind from the mine The methodology adopted has formed a guideline to assess the impacts due to such projects, and can be utilized on an industrial scale at various sites.
|Indian Patent Application Number||15/CAL/2000|
|PG Journal Number||09/2007|
|Date of Filing||12-Jan-2000|
|Name of Patentee||DR. MRINAL K. GHOSE|
|Applicant Address||CENTRE OF MINING ENVIRONMENT INDIAN SCHOOL OF MINES DHANBAD-826004|
|PCT International Classification Number||E 21F 5/00|
|PCT International Application Number||N/A|
|PCT International Filing date|