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The environmental impact of gold mines: pollution by heavy metals

Article in Open Engineering · June 2011

DOI: 10.2478/s13531-011-0052-3

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 Cent. Eur. J. Eng. • 2(2) • 2012 • 304-313
DOI: 10.2478/s13531-011-0052-3

Central European Journal of Engineering

The environmental impact of gold mines: pollution by

heavy metals
Research article

Sabah Ahmed Abdul-Wahab1∗ , Fouzul Ameer Marikar2

1 Department of Mechanical & Industrial Engineering, College of Engineering, Sultan Qaboos University, Sultanate of Oman

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2 College of Engineering, Sultan Qaboos University, Sultanate of Oman

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Received 23 August 2011; accepted 7 October 2011

Abstract: The gold mining plant of Oman was studied to assess the contribution of gold mining on the degree of heavy metals
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into different environmental media. Samples were collected from the gold mining plant area in tailings, stream
waters, soils and crop plants. The collected samples were analyzed for 13 heavy metals including vanadium
(V), chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), cadmium (Cd), cobalt (Co), lead (Pb), zinc (Zn),
aluminium (Al), strontium (Sr), iron (Fe) and barium (Ba). The water in the acid evaporation pond showed a high
concentration of Fe as well as residual quantities of Zn, V, and Al, whereas water from the citizens well showed
concentrations of Al above those of Omani and WHO standards. The desert plant species growing closed to the
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gold pit indicated high concentrations of heavy metals (Mn, Al, Ni, Fe, Cr, and V), while the similar plant species
used as a control indicated lesser concentrations of all heavy metals. The surface water (blue) indicated very
high concentrations of copper and significant concentrations of Mn, Ni, Al, Fe, Zn, lead, Co and Cd. The results
revealed that some of the toxic metals absorbed by plants indicated significant metal immobilization.
Keywords: Environment • Gold mining • Heavy metals • Pollution • Tailings • Soil • Water
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© Versita sp. z o.o.

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1. Introduction of the desired fraction and disposal of the wastes, often

as slurry, to a tailings or retention pond. More than 99%
of the original material may finally become tailings when
low-quality ores are utilized [3].
Mining has been identified as one of the human activities
Impacts of mining range from physical/habitat destruction
which may impact negatively on the quality of the environ-
with accompanying the loss of bio-diversity resources to
ment [1]. It causes the destruction of natural ecosystems
the accumulation of pollutants in different media of the en-
through removal of soil and vegetation and burial beneath
vironment [4]. Therefore, the mining sites are a permanent
waste disposal sites [2]. In principle, mining waste can be
toxicological problem for the surrounding ecosystems and
divided into two categories: (i) mine tailings, generated
human health [5]. Like any productive activity, the exploita-
when processing the ore, and (ii) waste rock produced
tion of mineral resources produces negative impacts upon
when uncovering the ore body. Many processing methods
the three elements in the environment: water, atmosphere
for minerals involve grinding of rock and ores, recovery
and soil [6].
The mining sites are often contaminated with several kinds
∗
E-mail: sabah1@squ.edu.om of heavy metals that come primarily from the processing

304
Sabah A.A., Fouzul A.M.

of ores and disposal of tailings and wastewaters around centration of heavy metals were documented and reported
mines [1, 7] These heavy metals can be released into the from different parts of the world [4, 27–33].
environmental media especially water, sediment and soil One of the most important environmental problems linked
[5, 8–10] According to certain changes in the physical and to metal mining activities is acid mine drainage (AMD),
chemical properties in the Lithosphere, heavy metals in which is produced by oxidation of pyrite and other metallic
tailings can be transported to, dispersed to, and accumu- sulphides [34–36]. The genesis of the acid drainage and
lated in plants and animals, and can then be passed up the main physical, chemical and biological factors which
the food chain to human beings as a final consumer [11]. are involved in this process were widely studied by many
In addition, the tailings contain many heavy metals, some investigators [37, 38].
of which are toxic contaminants in the soil that may cause Being a precious metal which is found in small quantities,
adverse effect on the ecosystem around the metal mines gold mining operations tend to cover wide areas, and thus
[11–13]. Therefore, contamination of soils, sediments, water can inflict environmental damage over a geographically
and biota by heavy metals is a primary concern in the wide area. The mining process sometimes is complex and
mining sites because of their toxicity, persistence, and results in the release of highly toxic pollutants. Gold
accumulation in food chains [1]. mining tends to have huge negative impacts on the envi-
Heavy metals associated with mining are of particular ronment from digging out a huge pit, to disposing of the

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interest for a number of reasons. Firstly, they show a left over chemicals and tailing. The environmental impacts
tendency to accumulate in sediments and soils and have a of gold mining are particularly severe because of the chem-

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long persistence time (are not biodegradable). Secondly, ical processes often used to extract gold. At the present
they are ubiquitous in sediments and soils arising from time, the cyanide leaching technique is used in extracting
both natural and anthropogenic sources with pathways gold. This process is particularly damaging the environ-
including inheritance from the parent rocks, application ment, infringes the principle of sustainable development,
of water as well as local and long-range atmospheric and consumes large quantities of water and energy, contributes
fluvial deposition of emissions from dust and mining [4]. to global warming, emits hydrogen cyanide and creates a
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These metals can then enter the food chain via uptake by morass of hazardous waste. Land, water, and air pollution
plants and animals including man [4, 14–16]. are all a byproduct of gold mining through the cyanide
Although many heavy metals at low concentrations have an heap-leaching method. Open pits can also lead to the
essential role as nutrients for plants, animals and human destruction of villages and relocation of communities. Gold
health, some if present at higher quantities and in certain mining disturbs the landscape, the water table, the geo-
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forms may also be toxic and can cause harm to life [17–20]. logical stability and the surrounding ecosystems because
Copper (Cu) and zinc (Zn) provide clear examples, both the large amounts of ore have to be removed to get small
being essential for normal metabolism and both can be amounts of gold. Gold mining disturbs underground water
toxic in high concentrations [21]. When the quantities of and pollutes water systems. Gold mining creates moun-
Cu and Zn in the body increase they become toxic, which tains of toxic waste because of the nature and quantities of
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can result in damaged and malfunctioning human organs. chemicals used in processing gold. It also produces noise
Heavy metals like Arsenic (As), lead (Pb), and cadmium pollution, which is caused by blasting and the movement
(Cd) are believed to cause cancer, neural and metabolic of large vehicles.
disorders and other diseases [4, 16]. Arsenic is considered In both underground and opencast mines, exposure to dust
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one of the most important contaminants of drinking water is a major problem. This dust can be toxic and radioac-
in the world as it causes cancer of the skin, lungs, urinary tive. This is a true problem for workers, but can also be
bladder and kidney. Lead is another metal of great concern a dangerous problem for communities located near mines,
as it can cause brain, liver and kidney damage in children especially in areas where roads are unpaved. Therefore,
and nerve damage in adults, while long term exposure to opencast mining can have a damaging impact on the ordi-
cadmium can cause kidney failure, liver, bone and blood nary activities of people living in rural areas.
damage [5]. Land pollution is the contamination of land by solid and
Heavy metals cause oxidative stress in plants [22–25]. hazardous wastes. This is really dangerous to the land
Metal stress was reported to affect photosynthesis, chloro- and the people around. These toxic waste storage places
phyll fluorescence and stomatal resistance [26]. For in- cause problems to the local environment as well as the
stance, copper inhibits photosynthesis and reproductive local citizens. Birth defects, sickness, and even death have
processes; lead reduces chlorophyll production, while ar- all been observed in people surrounding these toxic waste
senic interferes with metabolic processes. Consequently, storage facilities.
plant growth is reduced or impossible [5]. A number of Air pollution occurs when more pollutants are emitted into
case histories related to health problems due to excess con- the atmosphere that can be safely absorbed and diluted by

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 The environmental impact of gold mines: pollution by heavy metals

natural processes. This is seen in cases when the locations 2. Leaching and adsorption to extract the precious
of the digging sites are in remote areas and the machines, metals from the rock.
the waste removal trucks, and the workers travel back and
forth to complete the job. By making all of these trips and 3. Recovery of gold to produce dore bullion bars.
with some of the trucks that are used the emissions are
massive. All the CO2 that are entering the air causes acid Fig. 1 shows the gold plant under investigation. The plant
rain and holes in the atmosphere, which is a contributor is divided into 4 main areas: (1) crushing, (2) grinding
to the global warming. and sizing, (3) leaching, adsorption and filtration, and (4)
Open cast mining has a very direct effect on the water elution and gold room.
table in the area of the mine. As soon as the pit goes below
the line of the water table, the water table around the pit 2.1. Crushing
has to be lowered otherwise the pit would be flooded. The
water around the pit is pumped out for kilometres, meaning The ore is stockpiled and the process begins by feeding
that wells dry up and ecosystems linked to the water table the ore into a hopper with a loader. The ore is then drawn
(like wetlands and rivers) are seriously disturbed. Cyanide via a variable speed hydraulically driven belt feeder and
used to extract gold can pollute the rivers and can kill delivered to the crusher. Crushing is carried out in a jaw

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fish and other lives. Other waste products can also have crusher. Crushed ore is conveyed directly into the ball
bad effects on water quality. The air around a gold mine mill.

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can also easily be polluted. Dust from open mine pits can
blow around into the community. Both the mental health of 2.2. Grinding and sizing
workers and those living near mines will be badly affected.
In this work, the gold plant in Oman was studied to see the In this area, grinding and size classification will be carried
contribution of gold mining to the accumulation of heavy out in order to reduce the ore down to a fine particle size.
metals in different environmental media. The ore is conveyed directly from the jaw crusher into
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the ball mill. This ball mill has a larger proportion of
steel balls to assist in the grinding process. Water from
2. Processing plant the process water tank is also added inside the ball mill
to assist in the grinding process inside it. At the end
At the processing plant, gold is extracted from the ore by of the day, the grinding process inside the ball mill will
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cyanide leaching method where piles of crushed ore are reduce the ore to slurry that has a very fine particle size.
soaked with cyanide solution. The ore processing consists The outlet discharge of the mill is then pumped to the
of the following stages: cyclones. The cycle underflow gravity flows back to the
mill for further grinding and the cyclone overflow gravitates
• Crushing and grinding of the ore. over the trash screen and into the leaching and adsorption
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• Addition of the process water to form slurry. area. It should be noted that fine particle size is required
for gold liberation so the cyanide will be able to see the
• Addition of lime to the ore, and cyanide solution to gold in the leaching process.
the slurry, to leach the gold into solution.
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• Addition of carbon to adsorb dissolved metals and 2.3. Leaching, adsorption and filtration
to remove them from the slurry.
This area consists of two leaching tanks and six adsorption
• Stripping the metals from the carbon by acid wash- tanks. Sodium cyanide and caustic soda are added into
ing and circulation of a caustic cyanide solution. the first and second leaching tank. The tanks provide
sufficient retention time to allow the gold to be dissolved
• Precipitation of the gold by electro-winning.
by the cyanide solution. The slurry then moves through
• Smelting of metal products into bars of dore bullion. six carbon adsorption tanks. The primary objective of
the carbon is to remove (adsorb) the gold from the slurry
• Pumping of the barren slurry (tailings) to the tailings solution leaving the leaching tanks. Carbon will be fed
storage facility. into the circuit in the opposite direction to the slurry flow,
The above stages can be described under three main steps: moving from the last adsorption tank to the first. This
is because the gold moves towards the surface of carbon
1. Grinding and size classification to reduce the ore via a diffusive process. Therefore, the fresh carbon is fed
down to a fine particle size. through the last adsorption tank to scalp the gold that

306
Sabah A.A., Fouzul A.M.

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Figure 1. Flow chart of gold mining plant.

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 Figure
Figure 2.
2. Photograph
Photograph
The environmental
shows
shows
impact of gold
the
mines:the
open
open
pollution
pit.
by pit.
heavy metals

Figure 2. Photograph shows the open pit. Figure 3.

Figure 3. Photograph
Photograph shows the
the jaw
jaw crusher.
crusher.
Figure 2. Photograph shows the open pit. Figure 3. Photograph shows the jaw crusher.

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has not been removed in the previous adsorption tanks.
The carbon will be eventually removed from the circuit at
the first adsorption tank for stripping (i.e., loaded carbon).
By the time the slurry reaches the final adsorption tank,
most of its gold has been removed by the carbon (i.e., the
barren slurry). The barren slurry then passes out the final
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adsorption tank to the tailings filter needle tank. Slurry
from the tailings filter needle tank is pumped into the filter
press and is dewatered. The filter cake is dropped from
the filter press onto the ground where it is removed by
front end loader, loaded onto trucks and dumped into the
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tails dam. The filtrate gravity flows to the process water

tank.
Figure 3. Photograph shows the jaw crusher. Figure 4. Photograph shows the ball mill.
2.4. Elution and gold room Figure4.4.Photograph
Figure Photograph shows
shows the the
ball mill.
ball mill.
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Carbon loaded with gold (i.e., loaded carbon) is then air-

lifted from the first adsorption tank. It is pumped to the
elution circuit where the gold is washed off with super- and raw soil is cut terraced to the bottom of the pit until it
heated water. The washed solution (called pregnant eluate) reached the ground water table. Samples were collected
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is passed to the electrowinning circuit. The remaining bar- from the different sampling areas as indicated in Table 1.
ren carbon is reactivated by acid washing and returned
back to the last adsorption tank.
Real photographs of the open pit, the jaw crusher, and the
ball mill are shown in Fig. 2, 3 and 4 respectively. Table 1. Sampling location.

Seq. Location
1. Raw feed soil
2. Soil open pit
3. Materials and methods 3. Blue surface water at bottom of terraced pit
4. acid evaporation pond
3.1. 3.1. Study site 5. Water from citizens well 500-1000 m north of mine ( used
Figure 4. Photograph shows the ball mill. for irrigation)
The plant is located in Wilayet Yanqol in Adaherh region 6. Crop plants
of the Sultanate of Oman. The plant production is almost 7. Plants from vegetation close to mine and control away
20 kg of gold per month. The pit is a mountainous terrain from mine

308
Sabah A.A., Fouzul A.M.

3.2. Samples and reagents

Table 2. Concentrations of heavy metals in soil samples.

Deionised ultrapure water (18 ohm-SG water, Germany) Parameter Raw ore used as gold plant
was used to dilute standards and samples. Analytical feed soil (mg/kg)
Grade 37% HCl (Aldrich) and 70% nitric acid, (Sigma- Cu 3240
Aldrich). ICP multi standards (1 and 2) were used to Mn 2865
generate a calibration curve to quantify the samples. Mi- Sr 680
Al 108476
crowave oven digestion has proved to be a suitable tech- Zn 964
nique to digest samples with complex matrices [39] and was Fe 14108
therefore used for digesting, soil samples and ashed plant Ni 282
samples. The soil sample, solid tailings and ashed plant Cr 486
samples were digested in teflon bombs using method EPA V 290
Cd 5.33
3050B in a microwave oven (ETHOSEL, Milestone Mi- Pb 96.82
crowave Stystem USA) with the following program; 8 min Mo 4.54
in phase one and 4 min in phase two at 200°C. The di- Co 101.2
gested samples were filtered using Whatman filter paper B 316.1

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and transferred to 100 ml volumetric flasks. The samples Ba 118.5
Li 30.63
were analysed using a PerkinElmer Inductively Coupled K 13970
Plasma-Optical Emission Spectrometer (ICP-OES). Six

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Pb n.d
reagent blanks were analysed with the samples but did Na 2410
not show any significant contamination. Mg 51571
Ca 58882
Plant samples were air dried, ground using a mortar and
S 24106
pestle and sieved (100 um). The sieved sample was then
ashed in a muffle furnace at 500°C and acid digested using
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ultrapure hydrochloric acid (37%) and nitric acid (70%) in of copper (1170 mg/L). In addition there were apprecia-
equal ratio in a microwave oven in two phases. bly high residual concentrations of manganese, aluminium,
zinc, iron, nickel, cadmium, lead, and cobalt. Heavy metal
pollution could be caused when such metals as cobalt,
4. Results and discussion copper, cadmium, lead, and zinc contained in mine tailings
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come in contact with scarce rainfall water. Metals are

The trace elements considered for this study were vana- leached out and carried downstream as water washes over
dium (V), chromium (Cr), manganese (Mn), nickel (Ni), the tailings. Although the metals can become mobile in
copper (Cu), cadmium (Cd), cobalt (Co), lead (Pb), zinc neutral pH conditions, leaching is particularly accelerated
(Zn), aluminium (Al), strontium (Sr), iron (Fe) and barium in the low pH conditions which for example are created in
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(Ba). The feed soil of the gold plant was analysed for the dissolution of some metals.
their metal concentrations which indicated high concen- Table 4 shows the analysis results of similar vegetation.
trations of copper (0.32%), manganese (0.29%), aluminum Plants taken from close to the gold pit and a control plant
(10.8%), iron (1.4%) and lesser concentrations of zinc, nickel, collected close to the citizens water well about 1000 metres,
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chromium, vanadium, lead and cobalt (Table 2). Mineral- north of the mine. Analysis of the desert plant close to
ized rocks which contain significant amounts of pyrite and the gold pit indicated an alarming increase in almost all
other sulphide minerals can cause pyrite oxidation and trace elements (Fe, Mn, Al, Zn, Cu, Ni, Cr, V, Co, Ba) and
the generation of acid solutions where heavy metals could a decrease in the lead and molybdenum concentrations
become highly mobile when scarce rainfall occurs in this when compared to the control desert plant. The boron
arid region. concentrations in this plant however showed an appreciable
Table 3 shows the result of the analysis of the soil and decrease (1.77% to 0.07%), when compared to the control.
water in an open pit from where the light blue coloured Despite the plants collected being of the same genus, the
surface water was collected. The soil indicated appre- metal immobilization capabilities depend very much on
ciably high copper concentrations (4.4%). Cadmium, lead, the availability of metal concentrations in the soil as it is
molybdenum and cobalt were showed marginally higher growing explaining the differences in metal concentrations.
concentrations in the soil from the open pit when com- Lead concentrations of 80 mg Kg−1 were observed in the
pared to the metal concentrations of the feed soil. The tailings and also high levels of lead were observed in
surface water from the bottom of the pit was light blue in the plants growing in close proximity to the gold mining
colour. The blue colour was due to the high concentration area. The plant control taken downstream had lesser

309
 The environmental impact of gold mines: pollution by heavy metals

Table 3. Concentrations of heavy metals in the soil and water in the Table 4. Concentrations of heavy metals in crop plant.
open pit.
Parameter Plant close to the Control plant
Parameter Soil from bottom of Blue surface water open pit (mg/kg) (mg/kg)
open pit (mg/L)
Cu 119.7 35.1
Cu 44156 1170 Mn 433.6 233.2
Mn 1780.2 23.7 Sr 7277 5102
Sr 409.6 8.04 Al 14834 1646
Al 14525 76.6 Zn 757.7 26.1
Zn 605.4 21.1 Fe 1349.4 129.3
Fe 9351 31.0 Ni 92.2 56.0
Ni 58.34 3.05 Cr 105.6 6.2
Cr 241.7 0.105 V 60.8 18.9
V 123.7 0.129 Cd n.d n.d
Cd 10.79 0.790 Pb 30.4 41.4
Pb 168.2 1.56 Mo 11.6 34.1
Mo 13.0 0.023 Co 9.2 n.d
Co 493.5 23.7 B 727.7 17793
B 192 1.25

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Ba 255.9 66.6
Ba 48.5 0.026 Li 6.0 3.2
Li n.d 0.117 K 120352 35672

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K 1522.5 3.77 Pb 12535 1110
Pb n.d n.d Na 5658 3986
Na 13287 246 Mg 88964 27302
Mg 64935 828 Ca 277889 334794
Ca 11988 245 S 10396 304888
S 151448 2780
n.d – not detected: < 0.01 mg/L
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and groundwater pollution. Furthermore, heavy metals in
tailings could be transported to, dispersed to, and accumu-
concentrations of heavy metals than the ones in close lated in plants and animals, and then passed through the
proximity. This indicates that there could be translocation food chain to human beings.
of these metals in metal rich soils from roots to the other The analysis of water from the acid evaporation pond (Ta-
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parts in the plants. In an environment where there is ble 6) indicates that the mining process has taken sufficient
less fodder the presence of toxic elements in soils could precautions to prevent environmental pollution. But soil
be ingested by livestock grazing in the vicinity of the samples taken from around the acid evaporation pond and
mining area and subsequently to the humans suggesting a the slurry sample taken from the tailing dump and ana-
potential contamination of the food chain which could give lyzed for some specific heavy metals (lead, cadmium, zinc
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rise to environmental and health problems. and copper) indicates otherwise with toxic concentrations
There is every possibility that toxic trace elements in of lead, cadmium, that any spill over from the acid evap-
the soil could enter the water table following rain and oration pond could solubilise the heavy metals and be
surface water. Some of these toxic metals such as lead transported downstream during the scarce rainy seaon and
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(Pb) was present at high concentrations not only in the translocated through plants to the human food chain.
soil but also in the plants of the surroundings and acid
evaporation ponds. Despite the excessive phytotoxicity
evidenced in soils analyzed containing high levels of metals, 5. Conclusions
posing a risk for the surrounding area [40] and its scarce
water resources the water from the Citizens Well about The highest potential threat for the environment is mostly
500–1000 m north downstream of the mine conformed to represented by mineralized rocks exposed in waste dumps
the Omani Standards for Drinking Water and the WHO and open pits. The water chemistry observed in the area,
standards for drinking water. clearly show that these materials, have a high capability
Table 5 indicates the analysis results of the water sample for acid drainage generation and release of toxic or harmful
obtained from the citizen’s well located about 500–1000 m, elements (Pb, Cd, Co, Cr, Cu, Ni). Moreover, the acid, high-
north of the gold Plant. The water is used only for agri- metal waters can cause contamination in the scarce local
culture. groundwater through the solubilisation of toxic metals.
Depending on the changes in their physical-chemical Although the analysis done on the well water from the
states, the metal contaminants could cause soil substrate vicinity did not conform to the Omani and WHO Standards

310
Sabah A.A., Fouzul A.M.

Table 5. Analysis of citizen’s well water. Table 6. Analysis of water from acid evaporation pond, soil sample
and slurry sample from tailings stockpile.
Parameter Value
Parameter Water from acid evaporation pond
Colour < 5 Hazen Units
(mg/L)
Odour None
pH 7.6 Cu 0.023
Electrical Conductivity 822 uScm-1 Mn n.d
Total Dissolved Solids (TDS) 427 mg/L Sr 1.96
Total Hardness as CaCO3 310 mg/L Al 0.195
Calcium Hardness 100 mg/L Zn 0.269
Magnesium Hardness 210 mg/L Fe 60.032
Total Alkalinity 190 mg/L Ni n.d
Carbonate Alkalinity 0 Cr n.d
Hydroxide Alkalinity 0 V 0.117
Turbidity 1.92 NTU Cd n.d
Cations Pb 0.030
Sodium 61.8 mg/L Mo 0.044
Potassium 2.9 mg/L Co n.d

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Calcium (Ca) 40.0 mg/L B 0.443
Magnesium (Mg) 50.9 mg/L Ba 0.062
Copper (Cu) 0.028 mg/L Li n.d

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Manganese (Mn) n. d K 4.20
Strontium (Sr) 1.87 mg/L Pb 0.112
Al 0.128 mg/L Na 75.7
Zinc (Zn) 0.387 mg/L Mg 66.5
Iron (Fe) 0.02 mg/L Ca 54.8
Nickel (Ni) n. d S 48.5
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Chromium (Cr) n. d n.d. – not detected: < 0.01 mg/L
V 0.127 mg/L
Cadmium (Cd) n. d
Lead (Pb) 0.565 mg/L problems. Finally, the presence of livestock grazing nearby
Mo 0.037 mg/L
the mining area suggests a potential contamination of the
Co n.d
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B 0.315 mg/L
food chain. The absence of any data on amounts of toxic
Ba 0.062 elements in soils and local vegetation makes this risk
Li n.d unquantifiable.
K 3.82 mg/L
P 0.5657 mg/L
Na 1617 mg/L
Acknowledgments
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Mg 61.47 mg/L
Ca 50.27 mg/L
S 75.7 mg/L The authors are grateful the Oman Mining Company LLC.
Anions Special thanks go to the Plant Manager at Rakah Gold
Fluoride (F) 0.16 mg/L Plant.
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Chloride (Cl) 88.29 mg/L

Bromide (Br) 0.37 mg/L
Nitrate (NO3 ) 19.14 mg/L
Sulphate (SO4 ) 80.52 mg/L References
Chemical Oxygen Demand* < 1.6 mg/L
*Minimum Detectable limit – 1.6 mg/L
n.d. – not detected: 0.1 mg/L [1] Donkor A.K., Bonzongo J.-C.J., Nartey V.K., Adotey
D.K., Heavy metals in sediments of the gold mining
impacted Pra River basin, Ghana, West Africa, Soil
for drinking water because of a high concentration of Alu- and Sediment Contamination, 14(6), 2005, 479–503
minum, these threats to the local water chemistry must be [2] Cooke J.A., Johnson M.S., Ecological restoration of land
carefully considered in the future plans. with particular reference to the mining of metals and
Tailings are also a potentially harmful material, because industrial minerals: A review of theory and practice,
of the high metal and cyanide contents. However, their Environ. Rev., 10(1), 2002, 41–71
confinement to a restricted site should mitigate their envi- [3] Ledin M., Pedersen K., The environmental impact of
ronmental impact but spill over could pose environmental mine wastes – Roles of microorganisms and their sig-

311
 The environmental impact of gold mines: pollution by heavy metals

nificance in treatment of mine wastes, Earth Sci. Rev., [18] Lottermoser B.G., Gold in municipal sewage sludges:
41(1–2), 1996, 67–108 A review on concentrations, sources and potential
[4] Getaneh W., Alemayehu T., Metal contamination of extraction, J. Solid. Waste. Tech. Manag., 27(2), 2001,
the environment by placer and primary gold mining in 69–75
the Adola region of southern Ethiopia, Environ. Geol., [19] Rowe Jr. G.L., Reutter D.C., Runkle D.L., Hambrook J.A.,
50(3), 2006, 339–352 Janosy S.D., Hwang L.H., Water quality in the Great
[5] Franco-Hernández M.O., Vásquez-Murrieta M.S., and Little Miami River Basins, Ohio and Indiana,
Patiño-Siciliano A., Dendooven L., Heavy metals con- 1999–2001. US Geol. Surv. Circular, (1229), 2004a,
centration in plants growing on mine tailings in Central iv-32
Mexico, Bioresource Technol., 101(11), 2010, 3864– [20] Rowe J., McKnight S., Hall S., The biological oxi-
3869 dation of carbonaceous material in the treatment of
[6] González I., Jordán M.M., Sanfeliu T., Quiroz M., De a refractory gold bearing ore, Australasian Institute
La Fuente C., Mineralogy and heavy metal content of Mining and Metallurgy Publication Series, 2004b,
in sediments from Rio Gato, Carelmapu and Cucao, 173–174
Southern Chile, Environ. Geol., 52(7), 2007, 1243–1251 [21] Thornton I., Impacts of mining on the environment;
[7] Grimalt J.O., Ferrer M., MacPherson E., The mine some local, regional and global issues, Appl. Geochem.,

y
tailing accident in Aznalcollar, Sci. Total Environ., 11(1–2), 1996, 355–361
242(1–3), 1999, 3–11 [22] Fayiga A.O., Ma L.Q., Cao X., Rathinasabapathi B.,

op
[8] Eisler R., Health risks of gold miners: A synoptic Effects of heavy metals on growth and arsenic accumu-
review, Environ. Geochem. Health, 25(3), 2003, 325– lation in the arsenic hyperaccumulator Pteris vittata
345 L, Environ. Pollut., 132(2), 2004, 289–296
[9] Eisler R., Arsenic hazards to humans, plants, and [23] Fayiga A.O., Ma L.Q., Arsenic uptake by two hyperac-
animals from gold mining, Rev. Environ. Contam. T., cumulator ferns from four arsenic contaminated soils,
180, 2004, 133–165 Water Air. Soil. Pollut., 168(1–4), 2005, 71–89
rc
[10] Eisler R., Mercury hazards from gold mining to humans, [24] Fayiga A.O., Ma L.Q., Santos J., Rathinasabapathi B.,
plants, and animals, Rev. Environ. Contam. T., 181, Stamps B., Littell R.C., Effects of arsenic species and
2005, 139–198 concentrations on arsenic accumulation by different
[11] Kim K.-K., Kim K.-W., Kim J.-Y., Kim I.S., Cheong fern species in a hydroponic system, International
Y.-W., Min J.-S., Characteristics of tailings from the Journal of Phytoremediation, 7(3), 2005, 231–240
ho

closed metal mines as potential contamination source [25] Fayiga A.O., Ma L.Q., Zhou Q., Effects of plant arsenic
in South Korea, Environ. Geol., 41(3–4), 2001, 358–364 uptake and heavy metals on arsenic distribution in
[12] Kim K.W., Lee H.K., Yoo B.C., The environmental im- an arsenic-contaminated soil, Environ. Pollut., 147(3),
pact of gold mines in the Yugu-Kwangcheon Au-Ag 2007, 737–742
Metallogenic Province, Republic of Korea, Environ. [26] Monni S., Uhlig C., Hansen E., Magel E., Ecophysio-
ut

Technol., 19(3), 1998, 291–298 logical responses of Empetrum nigrum to heavy metal
[13] Jung M.C., Thornton I., Heavy metal contamination of pollution, Environ. Pollut., 112(2), 2001, 121–129
soils and plants in the vicinity of a lead-zinc mine, [27] Ashley P.M., Lottermoser B.G., Arsenic contamination
Korea, Appl. Geochem., 11(1–2), 1996, 53–59 at the Mole River mine, northern New South Wales,
A

[14] Aslibekian O., Moles R., Environmental risk assess- Aust. J. Earth. Sci., 46(6), 1999, 861–874
ment of metals contaminated soils at silvermines [28] Lottermoser B.G., Ashley P.M., Lawie D.C., Environ-
abandoned mine site, Co Tipperary, Ireland, Environ. mental geochemistry of the Gulf Creek copper mine
Geochem. Health, 25(2), 2003, 247–266 area, north-eastern New South Wales, Australia, Env-
[15] Grzebisz W., Cieśla L., Komisarek J., Potarzycki J., iron. Geol., 39(1), 2000, 61–74
Geochemical Assessment of Heavy Metals Pollution [29] Ogola J.S., Mitullah W.V., Omulo M.A., Impact of gold
of Urban Soils, Pol. J. Environ. Stud., 11(5), 2002, mining on the environment and human health: A
493–499 case study in the Migori Gold Belt, Kenya, Environ.
[16] Patel K.S., Shrivas K., Brandt R., Jakubowski N., Corns Geochem. Health, 24(2), 2002, 141–158
W., Hoffmann P., Arsenic contamination in water, soil, [30] Miller J.R., Hudson-Edwards K.A., Lechler P.J., Preston
sediment and rice of central India, Environ. Geochem. D., Macklin M.G., Heavy metal contamination of water,
Health 27 (2), 2005, 131–145 soil and produce within riverine communities of the Río
[17] Crounse R.G., Pories W.J., Bray J.T., Mauger R.L., Geo- Pilcomayo basin, Bolivia, Sci. Total Environ., 320(2–3),
chemistry and man: health and disease. 1. Essential 2004, 189–209
elements, Appl. Environ. Geochem., 1983, 267–308 [31] Von Der Heyden C.J., New M.G., Groundwater pol-

312
 Sabah A.A., Fouzul A.M.

lution on the Zambian Copperbelt: Deciphering the Iron Mountain, California, Environ. Sci. Tech., 34(2),
source and the risk, Sci. Total Environ. 327(1–3), 2004, 2000, 254–258
17–30 [37] Harries J.R., Ritchie A.I.M., Pore gas composition in
[32] El-Moselhy K.M., Gabal M.N., Trace metals in water, waste rock dumps undergoing pyritic oxidation, Soil
sediments and marine organisms from the northern Sci., 140(2), 1985, 143–152
part of the Gulf of Suez, Red Sea, J. Mar. Syst., 46(1–4), [38] Lefebvre R., Hockley D., Smolensky J., Gélinas P.,
2004, 39–46 Multiphase transfer processes in waste rock piles pro-
[33] Lottermoser B.G., Ashley P.M., Tailings dam seepage ducing acid mine drainage. 1: Conceptual model and
at the rehabilitated Mary Kathleen uranium mine, system characterization, J. Contam. Hydrol., 52(1–4),
Australia, J. Geochem. Explor., 85(3), 2005, 119–137 2001, 137–164
[34] Nordstrom D.K., Alpers C.N., Negative pH, efflores- [39] Lo J.M., Sakamoto H., Comparison of the acid com-
cent mineralogy, and consequences for environmen- binations in microwave-assisted digestion of marine
tal restoration at the iron mountain superfund site, sediments for heavy metals analyses, Anal. Sci., 21(10),
California, Proceedings of the National Academy of 2005, 1181–1184
Sciences of the United States of America, 96(7), 1999, [40] Boisson J., Ruttens A., Mench M., Vangronsveld J.,
3455–3462 Evaluation of hydroxyapatite as a metal immobilizing

y
[35] Nordstrom D.K., Advances in the hydrogeochemistry soil additive for the remediation of polluted soils. Part
and microbiology of acid mine waters, Int. Geol. Rev., 1. Influence of hydroxyapatite on metal exchangeability

op
42(6), 2000, 499–515 in soil, plant growth and plant metal accumulation,
[36] Nordstrom D.K., Alpers C.N., Ptacek C.J., Blowes D.W., Environ. Pollut., 104(2), 1999, 225–233
Negative pH and extremely acidic mine waters from
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ut
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