© 2022, IRJET | Impact Factor value: 7.529 | ISO 9001:2008 Certified Journal | Page 80 ANALYSIS OF HYDROGEOCHEMICAL AND MINERALOGICAL CHARACTERISTICS RELATED TO HEAVY METAL ATTENUATION IN A STREAM POLLUTED BY ACID MINE DRAINAGE: A CASE STUDY D. Sharma 1 , Dr. A. Bhatnagar 2 1 M. Tech. Student, Dept. of Mining Engineering, CTAE, MPUAT, Udaipur, Rajasthan, India. 2 Professor and Head, Dept. of Mining Engineering, CTAE, MPUAT, Udaipur, Rajasthan, India. ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - Acid mine drainage discharged from the mine may be harmful for the environment as well as for the human beings. The study area comprises of underground metal mine working and the Banas river which flows nearby the mining area. In this study, chemical characteristics if the water samples, mineralogy of the AMD sediments and heavy metal attenuation are discussed on the basis of mineral analysis, chemical analysis and sequential extraction techniques. The chemical characteristics of the acid mine drainage and sulfide minerals from the mine tailings are determined in order to study the impact of acid mine drainage of the river water. The water samples are classified as affected and unaffected water. The affected water has low pH value, high (SO4) 2- ions and high heavy metal concentration. The concentration of heavy metals and sulfide ions decreases and the pH increases downstream. The acid mine drainage water chemistry is controlled by the transformations and mineral precipitates of Fe 3+ minerals. Key Words: Acid mine drainage, Sediments, Mineralogy, Attenuation, Sequential extraction, Heavy metal 1.INTRODUCTION Mining has been important part in human world. It provides various minerals and coal that has been used in regular basis e.g. Thermal Power Plants, Cement Industry etc. But there exists various problems like Acid Mine Drainage. It is one of the major problems polluting the water as it pollutes around 27 billion of water per year. Human health has been major issue which surrounds the mine area. A mine draining acid can destroy streams, rivers, and aquatic life for hundreds of years. Oxidation and liberation of sulfur present in rocks in the form of sufide minerals generates sulfuric acid. This is one of the major impacts of coal and metal mining activity. Acid Mine Drainage (AMD) is a problem that initiates within short time in sulfide rich mines. When these sulfide minerals comes in contact with oxygen or oxygenated waters, breakdown of these minerals leads to acid generation and leaching of metals. Acid mine drainage leads to the problems like contaminated drinking water, disrupted growth and reproduction of aquatic plants and animals and the corroding effects of the acid on infrastructures such as bridges, etc. Treatment of AMD by conventional methods include various physicochemical methods, which involve excessive use of chemicals and capital. Biological treatment has come out as efficient, cost-effective, and eco-friendly alternative for remediation of AMD. Biological treatment methods involve use of microorganisms such as bacteria and fungi. Biotechnological approaches can prove an asset in developing techniques that can treat AMD in an effective way without affecting the environmental sustainability. Heavy metal contamination has slowly become a common and important concern world-wide. The most common heavy metals are iron, copper, zinc, lead, nickel, arsenic, mercury and cadmium. Heavy metals are distributed in the aquatic environment as sedimentary phases, suspended forms, colloids and water-soluble species. Heavy metals are an important category of pollutants as they can have a significant harmful effects on both human health and the health of terrestrial and aquatic communities and ecosystems. A number of heavy metals have been commonly studied as pollutants due to high environmental concern, such as Cd, Cu, Cr, Hg, Pb, Ni, and Zn. The danger of heavy metal pollution can be understand by three fundamental reasons. They are not biodegradable, so they remain indefinitely in the environment, unless transported to other environments. They can be retained by organic tissues through bioaccumulation and then transmitted to other species in a higher level of the tropic chain, thus causing biomagnifications. Some of them such as copper, zinc and manganese are necessary micronutrients for some plants and animals, but they can become lethal above certain concentration levels. However, organisms need these metals within an optimal level, under which conditions of want appear and over which we find toxicity. The mine in the study area has been extensively mined with massive tailings left behind and the surroundings have borne the effects of AMD contamination. Production of AMD continues in the tailing reservoir. AMD discharge from the mine has caused severe environmental pollution and human health problems. International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395-0056 Volume: 10 Issue: 1 | Jan 2023 www.irjet.net p-ISSN: 2395-0072