Studies on environmental impact of acid mine drainage generation and its treatment : an appraisal

Acid mine drainage is the most significant environmental pollution problem associated with mining industry. The main cause of acid mine drainage is the occurrence of pyrite and sulphide minerals with the rock of coal seams. During mining these sulphide minerals get exposed to air and mine water, then oxidation and hydrolysis results in the generation of acid mine drainage. The low pH value of the discharge mine water results in the future dissolution of minerals and release of toxic metals, when it allowed getting discharge into other water bodies. This acidity and high toxic metals concentration are harmful to the vegetation, aquatic life and wild life. The review paper describes the general chemistry of acid mine drainage generation; its impact on environment: different treatment techniques as remedial and control measures and future trend in treatment technology

Ground water quality evaluation near mining area and development of heavy metal pollution index

Opencast as well as underground coal mining are likely to disturb the underground water table in terms of quantity as well as quality. Added to this is the problem of leachates from the large number of industrial waste and overburden dumps that are in abundance in mining areas, reaching the ground water and adversely affecting its quality. Enhancement of heavy metals contamination of the ground water is one eventuality. In the present work, concentrations of 7 heavy metals have been evaluated at 20 important ground water sampling stations at Dhanbad township situated very near to Jharia coalfields. The concentration of heavy metals in general was found to be below the permissible levels although concentration of iron and manganese was found above the permissible limits at a few stations. These data have been used for the calculation of heavy metal pollution index (HPI). The HPI of ground water in total was found to be 6.8860 which is far below the critical index limit of 100 pointing to the fact that the ground water is not polluted with respect to heavy metals in spite of the prolific growth of mining and allied industrial activities near the town

Treatment of Acid Mine Drainage Using Fly Ash Zeolite

In this paper, two Indian fly ashes (from Talcher and Ramagundam) were converted into zeolites and both the raw fly ash and zeolite were used to treat two British acidic mine waters. The results demonstrate that fly ash zeolites are more effective than raw fly ash for treatment of acid mine drainage. Fly ash has been found effective for removal of Pb, but with increased dosing, caused release of Ba, Cr, Sr (both fly ashes) plus Zn, Ni (Talcher), or Fe (Ramagundam) into mine water. In contrast, increased dosing with fly ash zeolite removed 100% Pb, 98.9% Cd, 98.8% Zn, 85.6% Cu, 82.8% Fe, 48.3% Ni, and 44.8% Ba from mine water. Fly ash is amorphous in nature and many metals attached on the surface of the ash particles are easily leached off when ash comes in contact with acidic mine water. However, fly ash zeolite is crystalline in nature and due to its high cation exchange properties, most of the metals present in acid mine water are retained in surface sites

Quantitative Determination of Heavy Metals in the Water Samples of Four Fresh Water Ponds of a Mining Town

Quantitative investigation of two harmful heavy metals namely copper (Cu) and zinc (Zn) in the water of four most popular lakes of Dhanbad city namely: Bekar Badh lake, Ranitalab lake, Sri Sri Kali Mandir lake, and Bartand Badh lake have been carried out using atomic absorption spectroscopy (AAS). Calibration of the instrument was done using the standard solution. We have compared the obtained data of concentration of Zinc and Copper metal in water of these lakes with the standard maximum permissible limiting value set by Bureau of Indian Standards (BIS) IS:10500 Drinking Water Specification, 2004, considered fit for drinking by humans. The analysis showed that the concentration of heavy metals copper and zinc in four of the above mentioned lakes are much lower than the permissible limit prescribed by BIS and hence do not pose any direct threat to human life on consumption. We have also pointed out the factors responsible behind such contamination and identified the ways to control the contaminant in these water bodies

The Impact of Filling an Abandoned Open Cast Mine with Fly Ash on Ground Water Quality: A Case Study

Fly ash has been used to fill an abandoned open cast mine. Ground water samples were collected from the periphery of the ash-filled mine, from within the mine property, and a half kilometer away from the site; the pH and concentrations of total dissolved solids, total hardness, Ca, Mg, Cl, SO4, F, K, Cu, Cd, Cr, Fe, Pb, Zn, Mn, and Ni were determined. Concentrations of F and Mn were significantly greater in the ground water collected at the ashfilled mine than in the uncontaminated area, and are potentially a matter of concern. The other parameters were found to be affected but not at problematic levels

Determination of concentration of total sodium and potassium in surface and ground water using a flame photometer

In this paper, we have investigated 18 water samples collected from various sources, e.g., surface, underground and river water, as specimens for their sodium and potassium ions content in and around Dhanbad, a mining town, using the flame photometry. We have plotted the contour maps to show the spatial distributions of the dissolved sodium and potassium cations in the groundwater and surface water sources in and around the Dhanbad city to identify the relative contributions of human and natural phenomena to it. Along with it, water quality index (WQI) is calculated to evaluate whether the collected surface, ground and river water samples are fit for human consumption for the residents of those areas. The water of Maithan Dam has been observed to have the least sodium and potassium concentrations of 16 mg/l and 7 mg/l, respectively, which make it most suitable for human consumption. The water of Rani Talab Pond has the highest sodium and potassium contents of 49 mg/l and 24 mg/l. WQI values of all the samples are found to be less than 50, which indicates they are safe to consume by the humans. Reduction in the use of pesticides, potassium permanganate and water softeners is recommended to maintain WQI of the Dhanbad city within safe limit

Ground water quality evaluation in the lean period of a mining township

Groundwater of mining towns is very much affected due to mining activity. During mining of mineral from underground, huge quantity of ground water is pumped out to make mining possible. Groundwater samples have been collected from the 20 sampling sites of Dhanbad, a mining Township, in the lean period (summer) of the years 2011 and 2014. Four samples have been obtained from open well and 16 from hand pumps. Water quality parameters such as pH, total hardness, Ca hardness, Mg Hardness, chloride, sulphate, total dissolved solids, and heavy metals have been evaluated. The values of pH, total hardness, Ca hardness, Mg hardness, chloride, sulphate, and total dissolved solids have increased in 2014 as compared to 2011 which may be due to increase in mineral content in the lean period and decrease in the rate of recharge of aquifers in 2014. The concentration of heavy metals has decreased in 2014 as compared to 2011 which may be due to less leaching of heavy metals from the ground strata. From the overall study, it has been concluded that most of the water quality parameters of all the 20 groundwater samples in the year 2014 are not exceeding the acceptable concentration level, as mentioned in Indian drinking water specifications. Groundwater in the year 2014 has not shown any significant change in its quality as compared to the year 2011. In the incoming years, quality of groundwater will not show any drastic change unless and until any anthropogenic activity other than mining will affect it

Mercury Content around a thermal Power Plant in India : A case study

Burning of coal in thermal power plant is chief source of mercury presence in surrounding environment. In the present study total mercury content in different wastewater discharge from Tenughat Thermal power plant, nearby soil, different coal ashes and nearby ground water has been evaluated. In all samples mercury analysis has been carried out by using atomic absorption spectro photometer with hydride generator facility. From the results it has been seen that water discharge from different unit of TTPS has very low concentration of mercury. Soil samples showed quite high concentration of mercury as compared to nearby groundwater. Pond ash contained maximum concentration of mercury as compared to flyash, bottom ash and coal

Removal of Ammonia from coke-plant Wastewater by using synthetic Zeolite

Ammonia is discharged at significant concentrations in coke-plant effluents and can adversely impact freshwater-receiving streams. This article reports on the removal of ammonia from such wastewaters by using synthetic zeolites. Factors affecting the ammonium exchange capacity included the contact time, the concentration of ammonia in the solution, the particle size of the zeolites, the loading flow rates, and the number of regenerations of zeolite, the 13x molecular sieve has also been tested for its capacity to remove ammonia from coke-plant secondary wastewater. Results indicate that the ammonium adsorption rate increases with an increase in the contact time of zeolite with ammonia solution. Smaller particle size of the zeolite, increase in ammonium concentration, and lower loading flow rate elevate ammonium exhange capacity for the zeolite. Column, and repeated column regeneration of the zeolite with NaCl solution reactivates the zeolite column, and repeated column regeneration is possible without loss of ammonium uptake capacity