Content uploaded by Raj Mukhopadhyay
Author content
All content in this area was uploaded by Raj Mukhopadhyay on Jul 27, 2017
Content may be subject to copyright.
*Corresponding author’s email : nirmalde@gmail.com
1Research Scholar, 2Research Scholar, 3Professor, 4Ex M. Tech Scholar, 5 Professor, 6Sr. Manager (Envt.)
Eco. Env. & Cons. 22 (April Suppl.) : 2016; pp. (S207-S211)
Copyright@ EM International
ISSN 0971–765X
Chemical characterization of selected overburdens of
Singrauli coalfields
Mahendra Kumar Verma1, Priyal Pandey1, Raj Mukhopadhyay2, Nirmal De*3, Resham Dwivedi4,
N.C. Karmakar5 and V.K. Bajaj6
1Department of Soil Science and Agricultural Chemistry, IAS, BHU, Varanasi 221 005, U.P., India
2Division of Soil Science and Agricultural Chemistry, IARI, New Delhi, India
*3Department of Soil Science and Agricultural Chemistry, IAS, BHU, Varanasi, U.P., India
4,5Department of Mining Engineering IIT (BHU), Varanasi 221 005, U. P., India
6Northern Coalfields Limited, Singrauli.
(Received 20 October, 2015; accepted 25 December, 2015)
ABSTRACT
Mining particularly opencast mining contribute over 81% of total coal production in India. Opencast mining
releases huge amount of mining wastes to the upper part of the land surface as overburden dump materials.
Overburden materials are nutrient-poor, loosely adhered particles of shale, stones, boulders and cobbles
and are devoid of true soil character. A brief idea of chemical properties of overburden is necessary to carry
out successful eco restoration. In the present study overburden dumps of different ages under Singrauli
coalfields were collected and characterized for various chemical properties. Chemical characteristics such
as pH, Electrical conductivity, Organic carbon, Nitrogen, Phosphorus, Potassium, Calcium, Magnesium
and micronutrient were analyzed. The overburden samples collected from the coal mining areas had pH in
acidic range (6.1-6.7) while native forest has neutral pH (7.4). Organic carbon was found minimum in fresh
overburden (0.11%) and increased with age of overburden (0.34 %) in 15 year old overburden. Available
nitrogen and available phosphorus were deficient in overburden samples as compared to native forest soil.
Iron, Zinc and Copper were found to be in permissible limit in overburden samples and native forest soil.
Manganese was found to be deficient in overburden samples and native forest soil. Nickel was found
within permissible limits in different aged overburden as well as in soil. Present study revealed that
overburden samples were poor in nutrients but proper management with plantation of suitable plant species
could be helpful in improving availability of essential nutrients in overburdens.
Key words : Organic carbon, Coal, Opencast mines, Overburden materials, Mine spoil.
Introduction
Coal has relatively high importance for the economi-
cal growth of a country. India is the 3rd largest pro-
ducer of coal in the world and India has the 4th larg-
est reserves of coal in the world (approx. 197 billion
tonnes). Two types of mining are operated namely,
opencast and underground mining. Opencast min-
ing is bound to damage the natural ecosystem by
several sequences of mining activities. (Barpanda et
al., 2001). During opencast mining, the overlying
soil is removed and the fragmented rock is heaped
in the form of overburden dumps (Ghosh, 2002).
Dump materials are left over the land in the form of
overburden dumps. As the dump materials are gen-
erally loose, fine particles become highly prone to
S208 Eco. Env. & Cons. 22 (April Suppl.) : 2016
blowing by wind. Due to the adverse physicochemi-
cal and biological properties of mine spoil (Juwarkar
et al. 2004), natural succession of plant species on
these dumps is very slow (Singh et al., 1996, Ekka
and Behera, 2011) . The absence of any vegetation on
such dumps leads to further problem of soil erosion
and environmental pollution (Singh et al., 1996). The
nature tries to restore normally by operating plant
succession on spoils after certain interval of time
(Borpujari 2008; Hazarika et al., 2006). But it is a time
taking process, so artificial intervention in this pro-
cess is necessary.
Soil is a dynamic system, in which continuous
interaction between soil minerals, organic matter
and microorganisms influences the physico-chemi-
cal and biological properties of terrestrial ecosystem.
Anthropogenic activities such as mining activities,
specifically opencast mining, have resulted in dras-
tic alternations/ in their geochemical cycles and of-
ten lead to land degradation, with adverse changes
in soil textural and structural attribute. In view of
the increasing mining activities, decreasing soil fer-
tility and adverse effects on soil flora and fauna, it is
of utmost concern to monitor the physico-chemical
characteristics of coal mine.
Overburden spoil in a chronosequence, which not
only pave the way of greater understanding in the
direction of improving soil fertility and bio
remediation, but also is pre-requisite for assessing
the process of spoil reclamation, leading to the veg-
etational development/succession with respect to
time. Thus the main objective of the present study
was to characterize the chemical properties of over
burden material dumped in the mining site and ob-
serve the changes in the chemical properties of the
dumps, over a period of time, through the natural
process of reclamation.
Materials and Methods
Study area
The Bina Extension opencast Project (OCP) of
Northern Coalfields Limited (NCL) is located in
Singrauli Coalfields, which is situated partly in
Sonebhadra district of Uttar Pradesh and partly in
Singrauli district of Madhya Pradesh. The Mine
lease area falls within the latitudes 240o 09’ to 240o
11’ 22" N and Longitude 820o 44’ to 820o 45’ 25" E.
Bina extension opencast project lie on North West
side of the existing Bina project. The proposed ex-
pansion of existing Bina (Extn) is an opencast coal
mine for an enhanced of 7.50 Mtpa with a corre-
sponding peak OB removal of 39.38 Mm3 per year.
Bina (Extn.) block having an area of 1798 ha is lo-
cated partly in Singrauli district of M.P and partly in
Sonebhadra district of U.P. The mine lease area falls
in the hilly plateau with elevations as high as 490m
with undulating rugged topography (RL varying
from 275 m to 490 m) and sloping gently towards
south and east. The Bina Ext. project is planned to
mine the geological Chandela block, located in the
eastern part of Moher sub-basin which is entirely
covered by the rocks of upper Barakar with a thin
cover of soil and alluvium at places. The Barakar
sequence mainly consists of medium to coarse
grained, light grey open textured felspathic sand-
stone, shale, clay and coal.The minimum and maxi-
mum temperature of the area are 4oC and 48o C re-
spectively during the last 15 years. The area receives
mostly SW monsoon and average annual rainfall is
about 1105 mm. The peak relative humidity varies
from 41 to 88% during rainy season and from 16 to
62% during summer. The pre dominant wind direc-
tion recorded is from east to west with an average
wind speed of 3-53 km/hr for the last 15 years.
(a) Overburden (OB) sampling
In general, coal is a sedimentary formation. So the
overburden materials which include shale, sand-
stone and other impurities is generally heaped at the
mining site, during the time of opencast mining. The
overburden samples were collected by help of
spade, auger and khurpi. The sites from which OB
samples were collected are given in table 1. Com-
posite samples of 500 g were collected after quarter-
ing of samples and brought to laboratory for chemi-
cal analysis. The overburden samples were air dried,
cleaned, crushed in mortar and pestle and passed
through 2 mm mesh sieves and then analyzed for
chemical properties.
(b) Overburden Chemical Analysis
pH and Electrical conductivity were determined in
(soil/water 1:2.5) suspension with a pH meter and
Conductivity meter respectively. Organic matter of
the overburden dump materials was determined by
using the Walkley and Black method (Wakley and
Black, 1934). Available Nitrogen was determined by
the alkaline potassium per magnate method (Subiah
and Asijja, 1956). Available phosphorus content was
determined by Olsen’s method, Bray method( Bray
VERMA ET AL S209
and Kurtz, 1966), Available Potassium by neutral
normal ammonium acetate (Hanway and Heidal,
1952), Exchangeable Calcium and Magnesium by
versenate titration (Cheng and Bray, 1951), and mi-
cronutrients (Zinc, Copper, Manganese, Iron, and
Nickel) by DTPA extraction method (Lindsay and
Norvell, 1978).
Results and Discussion
The pH of these overburden samples was found to
be ranging from 6 to 7.4. pH of coal mine overbur-
den was found to be in acidic range, while pH of
forest soil was in neutral range. Yaseen et al., (2012)
reported similar result for overburden of Raniganj
coalfield, this acidic pH may be due to geology of
rocks in the area. The gradual increase in pH from
6.1 (fresh overburden) to 6.7 was due to plantations
and inputs of organic matter that modifies the pH of
the soil. Since the plant species are dicotyledonous,
they may release more base cations like Ca2+ into the
soil (highest Ca2+ was found in 15 year old mine
poil) thus increase the pH of the poil more than the
fresh mine soils.
EC was found to be ranged 0.07- 0.30 dS/m. For
mine soil, Saxena (1989), proposed that while EC <
4 dS/m may be considered to be good for plant
growth, EC values within the range of 0.7 to 0.8 dS/
m may be accepted as fair and soil/spoil with an EC
value 3 dS/m should be considered to be of poor
quality. During study period, EC was found to be
ranged 0.07- 0.30 dS/m. The variation of EC values
are attributed by leaching, composition of parent
materials and plants uptake. The observed EC value
is within the plant growth limit. Soluble salt concen-
trations of >1–3 dS/m were unfavourable for plant
growth and tree survival (McFee et al., 1981). The
three major macronutrients, namely nitrogen (N),
phosphorus (P) and potassium (K) are generally found
to be deficient in overburden dumps. Similar result
was found by Coppin and Bradshaw (1982),
Sheoran et al., (2008). Organic carbon levels greater
than 0.5% is rated as good quality of soil or dump
and less than 0.4% is rated as ordinary quality of
dump (Ghosh et al., 1983). The present study
showed percentage of organic carbon content rang-
ing from 0.11 % to 0.67%. Overburden samplea were
poor in organic matter as compared to native forest
soil. It may be due to poor microbial population in
overburden as compared to forest soil, which in turn
result into less decomposition of organic matter.
The nitrogen used by plants on dump materials
comes from organic matter, fertilizer application
and legumes plants (Maiti et al., 2002). In the present
study, available N was found to be ranged 0.6 kg/
ha to 112.9 kg/ha in different aged OB dumps and
the natural forest of studied area. However, avail-
Table 1. Sites of overburden samples
S. No. Sampling Location Code
1. Forest land NF
2. 5 Year old overburden S1
3. 12 Year old overburden S2
4. 15 Year old overburden S3
Table 2. Chemical Properties of selected overburden
SN Parameters Forest 5 Year old 12 Year old 15 Year old
Land over burden over burden over burden
(NF) S1 S2 S3
1. pH 7.4 6.1 6.34 6.7
2. Electrical conductivity (dS/m) 1.1 0.07 0.18 0.1
3. Organic carbon content (%) 0.67 0.11 0.26 0.34
4. Available N (kg/ha) 112.9 0.6 18.81 50.2
5. Available P (kg/ha) 0.74 0.28 0.36 0.53
6. Available K (kg/ha) 79.07 0 0 18.70
7. Available Ca (meq/L) 1.6 0.1 0.4 1.2
8. Available Mg (meq/L) 1.1 0 0.2 0.6
9. Available Zinc (ppm) 0.40 0.37 1.17 3.72
10. Available Iron (ppm) 4.53 7.14 7.9 4.38
11. Available Copper (ppm) 0.76 0.26 0.40 0.45
12. Available Manganese (ppm) 0.58 0 0 11.59
13. Available Nickel (ppm) 3.56 14.6 7.87 10.7
S210 Eco. Env. & Cons. 22 (April Suppl.) : 2016
able nitrogen content was found to be maximum
(112.896 kg/ha), in native forest due to higher
amount of mineralizable organic matter present in
the samples, and lower values (0.6 kg/ha) were re-
corded at S1 due to lower rates of organic matter
mineralization in the dump samples.
The available P of the overburden samples were
recorded in low amount at S1 (0.28 kg/ha). This
might be due to slightly acidic nature of samples
which restricted the microbial action activities re-
sulting in very poor mineralization and organic
matter decomposition process in the overburden
samples. The available phosphorus was recorded
high amount at forest land due to higher organic
decomposition process in the samples.
The available potassium was found to be nil in S1
and S2 which requires the use of fertilizers for better
plant growth. The available K was found to be 18.7
kg/ha and 79.07 kg/ha in S3 and forest land respec-
tively.
The amount of available Ca and Mg ions were
found to be 1.6 meq/L and 0.9 meq/L. The concen-
trations (in ppm) of different micronutrients, such as
zinc, copper, iron, manganese and nickel were
found to be 0.40, 0.76, 4.53, 0, 0.11 in forest land,
0.37, 0.26, 4.38, 0.58, 0.04 in S1, 1.17, 0.40. 7.9, 0, 0.28
in S2 and 3.72, 0.45, 7.14, 11.59, 0.71 in S3 respec-
tively. Iron manganese nickel found to be increased
with age of overburden similar result were obtained
by (Saviour and Stalin, 2012). Manganese content in
S2 is negligible; it may be due to conversion into in-
soluble form, as high pH of overburden spoil in acid
in reaetion.
Conclusion
From the above study, it can be concluded that the
overburden samples collected from the coal mining
areas were poor in organic carbon, available nitro-
gen and available phosphorus due to lower amount
of microbial activities. pH of all the sampling sites is
slightly acidic in nature. Under these (acidic) condi-
tions of dump materials, growth of plants is severely
affected in various ways. The data reveal that dump
materials are deficient in N, P, & K which requires
addition of extra fertilizer and manures to make the
dump suitable for any purpose. The dump material
at all the sampling sites was not found suitable for
plant growth. Micronutrients were not in toxic range
in fresh overburden, but aged overburdens have
high amount of micronutrient. Nickel concentration
in old overburden was high indicating a possible
buildup and problem in future. Future challenges in
crop productivity of the mining and mineral indus-
tries include the increasing scale of operations with
large mining companies seeking to exploit large re-
serves in more remote wilderness environments,
greater innovation in new technologies such as the
in situ extraction of metals through leaching, the in-
creasing need to regulate and develop environmen-
tal management in the artisanal and small mining
sector, and the imperative to incorporate policies of
sustainable development as far as possible. Most of
the new mining initiatives currently are in develop-
ing countries, and this will extend to mining of ore
deposits in more remote and fragile ecosystems.
The time has arrived for a rethinking on the way
mine contaminated site development programs are
planned and implemented around the world. It is
creditable that considerable progress has been
achieved during the past three decades in trans-
forming mine-contaminated lands into agricultur-
ally productive sites, though several knowledge
gaps exist even in areas that have received research
attention in the past.
References
Barapanda, P., Singh, S. K. and Pal, B. K. 2001. Utilization
of coal mining wastes: An Overview, National
Seminar on Environmental Issues and Waste
Management in Mining and Allied Industries,
Regional Engg College, Rourkela, Orissa, India. pp.
177-182.
Borpujari, D. 2008. Studies on the occurance and
distribution of some tolerant plant species in
different spoil dump of Tikak opencast nine. The
Ecoscan. 2 : 255-260.
Bray, R. and Kurtz, L. T. 1966. Determination of total,
organic and available forms of phosphorus in soil.
Soil Science, 59: 39 45.
Cheng, K. L. and Bray, R. H. 1951. Determination of
magnesium and calcium in soil and plant material.
Soil Sci. 72:44.
Coppin, N.J. and Bradshaw, A.D. 1982. The establishment
of vegetation in quories and open-pitnon metal
mines. Min. J. Books, London, 112.
Ekka, N. J. and Behera, N. 2011. Species composition and
diversity of vegetation developing on an age series
coal mine spoil in an open cast coalfield in Orissa,
India. Trop Ecol 52: 337 -343.
Ghosh, A.B., Bajaj, J.C., Hassan, R. and Singh, D. 1983.
Laboratory manual for soil and water testing.
Division of Soil Science & Agri. Chemistry, IARI.
New Delhi, India. pp. 11-22.
VERMA ET AL S211
Ghosh, R. 2002. Land use in mining areas of India. Envis
Monograph No.9 by CME, ISSN: 0972 4656.
Hanway, J.J. and Heidal, H. 1952. Soil analysis as used
in lowa State College of soil testing Laboratory.
Lowa. Agriculture. 57 : 1-31.
Hazarika, P., Talukdar, N.C. and Singh, Y.P. 2006.
Natural colonization of plant species on coal mine
spoils at Tikak calliery, Assam. Tropical Ecology. 47:
37-46.
Juwarkar, A. A., Jambulkar, H. P. and Singh, S. K. 2004.
Appropriate strategies for reclamation and
revegetation of coal mine spoil dumps. Proceedings
of the National Seminar on Environmental
Engineering with special emphasis on Mining
Environment, NSEEME-2004, India.
Lindsay, W. L. and Norvell, W. A. 1978. Development of
DTPA soil test for zinc, iron, manganese and
copper. Soil Sci. Am. Proc. 42 : 421 – 428.
Maiti, S. K., Karmakar, N. C. and Sinha, I. N. 2002. Studies
into some physical parameters aiding biological
reclamation of mine spoil dump- a case study from
Jharia coal field. Indian Mining Engineering Journal
41: 20-23.
McFee, W.W., Byrnes, W.R. and Stockton, J.G. 1981.
Characteristics of coal mine over-burden important
to plant growth. J. Environ. Qual. 10 : 300–308.
Saviour, N.M. and Statin, P. 2012. Soil and sand mining,
consequence and management. IOSR Journal of
Pharmacy. 2(4) : 01-06, ISSN: 2250-3013.
Saxena, M.M. 1989. Environmental analysis: water, soil
and air, Agro Botanical Publishers, Bikaner,
Rajasthan, 121140.
Sheoran, A.S., Sheoran, V. and Poonia, P. 2008.
Rehabilitation of mine degraded land by
metallophytes. Mining Engineers Journal 10 (3) : 11-
16.
Singh, R.S., Chaulya, S.K., Tewary, B. K. and Dhar, B. B.
1996. Restoration of a Coalmine overburden dump
A Case Study. Coal International.
Subbiah, B.W. and Asija, G.L. 1956. A rapid procedure
for estimation of available nitrogen in soil. Current
Science. 25 (8) : 259-260.
Walkley, A. and Black, I.A. 1934. An examination of the
Degtjareff method for determining soil organic
matter and a proposed modification of the chromic
acid titration method. Soil Science. 37 : 29-38.
Yaseen, S., Pal, A., Singh, S. and Yousuf Par, I. 2012. A
study of physico –chemical characteristics of
overburden dump materialfrom selected coal
mining areas of Raniganj coalfields, Jharkhand,
India. Global Journal of Science frontier Research
Environment & Earth Sciences. 12 : ISSN: 2249-4626.
