Biswajit Paul

The global menace of arsenic and its conventional remediation - A critical review.

Arsenic is a ubiquitous element found in the earth crust with a varying concentration in the earth soil and water. Arsenic has always been under the scanner due to its toxicity in human beings. Contamination of arsenic in drinking water, which generally finds its source from arsenic-containing aquifers; has severely threatened billions of people all over the world. Arsenic poisoning is worse in Bangladesh where As(III) is abundant in waters of tube wells. Natural occurrence of arsenic in groundwater could result from both, oxidative and reductive dissolution. Geothermally heated water has the potential to liberate arsenic from surrounding rocks. Inorganic arsenic has been found to have more toxicity than the organic forms of arsenic. MMA and DMA are now been considered as the organic arsenic compounds having the potential to impair DNA and that is why MMA and DMA are considered as carcinogens. Endless efforts of researchers have elucidated the source, behavior of arsenic in various parts of the environment, mechanism of toxicity and various remediation processes; although, there are lots of areas still to be addressed. In this article, attempts have been made to lay bare an overview of geochemistry, toxicity and current removal techniques of arsenic together.

UNDERGROUND COAL GASIFICATION: A NEGLECTED OPTION

The energy sector is crucial to development. Coal is the prime energy resource in the foreseeable future. There is urgent need to develop alternative energy sources, which are cleaner and able to meet the demand and supply gap of energy for development in an environmentally sustainable manner. Underground coal gasification is a neglected option.

An Overview of Use of Linz-Donawitz (LD) Steel Slag in Agriculture

Slag generated from basic oxygen furnace (BOF) or Linz-Donawitz (LD) converter is one of the recyclable waste in integrated steel plants. This paper deals with the present and possible use of LD slag in agriculture. At present, the amount of slag deposited in storage yard, leading to the occupation of farm land and serious pollution to the environment. Improving the slag utilization is an important way to resolve these problems. The physical and chemical characteristics of steel slag were analyzed and then introduced the research progress of steel slag utilization in agriculture as fertilizer. Due to increasing awareness of the environment, disposal, reuse of wastes without harming the environment has became a prime concern for the industry. The local availability of non conventional sources of plant nutrients and soil conditioners plays a vital role because of the non availability and higher price of environmental fertilizers. Therefore, this waste can be utilized for enhancing yield as well as solving the disposal problem and improve the environment.

Sustainable Approaches for LD Slag Waste Management in Steel Industries: A Review

Reduce, reuse, and recycle are important techniques for waste management. These become significant for improving environmental and economic condition of industries. Integrated steel industries are generating huge amounts of steel slag as waste through the blast furnace and Linz–Donawitz (LD) process. Presently, these wastes are disposed by dumping in an unplanned manner, which causes many environmental problems. The generation rate of slag produced from steel industries is found to be in the range of 150–200 kg per ton of steel production. The LD slag generated by the basic oxygen converter, is one of the waste which can be reused due to the presence of a considerable amount of valuable minerals. In order to recycle and reuse the waste, assessment of their physicochemical, mineralogical and geotechnical characterization is imperative. This paper addresses the characterization and possible utilization of LD slag.

Augmenting the Stability of OB Dump by Using Fly Ash: A Geo Technical Approach to Sustainably Manage OB Dump at Jharia Coalfield, India

This paper is mainly focused over the possible utilization of fly ash along with OB dump to enhance the stability of OB dump and thus provide a sustainable approach for better waste management of both these materials simultaneously. Instability of coal mine overburden (OB) dumps is an important problem in most of the coal mines like Jharia coalfields in India. This is mainly occurring due to sliding nature of the rock material, lack of vegetation etc. Numbers of Environmental and health issues are associated with these unstable OB dumps. As it may easily flow with running water can contaminate the nearby water resource as well as carbonaceous content of the dump causes air pollution due to simultaneous combustion. On the other hand management of coal ash that is produced from thermal plants is also an important task. Dumping of fly ash in open may cause number of environmental problems. Various geotechnical and physical parameters such as particle size analysis, specific gravity, density, and friction angle/cohesion test have been performed to check the stability of OB dump and to analyze impacts of fly ash utilization to stabilize the OB dump.

Microbial degradation of expired slurry explosives in mines: a review

Minerals are mostly produced from opencast and underground mines and blasting is an essential operation in India. Mining explosives and initiating accessories are used for removing overburden rocks and to produce minerals. Ammonium nitrate fuel oil (ANFO), emulsion (Water-in-Oil) and water gel slurry explosives are used in the blasting operations. In India, the quantity of cartridge slurry and bulk slurry explosives used in mining is approximately 30% of the total mining explosives consumed in the country. Huge amounts of slurry explosives deteriorate in storage, as their properties become impaired, and they should be discarded safely. The only method for disposal of slurry explosives is open burning, which creates air pollution. This paper reviews the characteristics of uni-molecular and slurry explosives and their available disposal methods.

Comparative analysis of different materials to be used for backfilling in underground mine voids with a particular reference to hydraulic stowing

A comparative analysis was performed between different materials like sand, pond ash, fly ash and OB with parameters such as grain size distribution, porosity, percolation, permeability, water holding capacity, bulk density and specific gravity to assess their suitability as a filling material in underground mine voids. All the parameters stated above have their direct or indirect effects on drainage property which is a key factor in hydraulic stowing (to achieve a stable packing). Grain size analysis result confirmed the sandy nature of OB with about 70% of sand size particles that is a good sign for its resemblance with natural sand and thus possible alternative of sand as a filling material. Other parameters like permeability, porosity and percolation was also found more or less similar to sand and better than other two materials. [Received: November 3, 2015; Accepted: March 10, 2016]

Erratum to: Sustainable Approaches for LD Slag Waste Management in Steel Industries: A Review

The online version of the original article can be found under doi: 10.1007/s11015-016-0261-3 .