Madhurya Ray

Bio: Madhurya Ray is an academic researcher from Indian Institutes of Technology. The author has contributed to research in topics: Wastewater & Freundlich equation. The author has an hindex of 3, co-authored 7 publications receiving 24 citations.

Assessment of water-quality parameters of groundwater contaminated by fly ash leachate near Koradi Thermal Power Plant, Nagpur.

Abstract: Thermal power generating industries affect the surrounding environment in various ways. Fly ash escapes along with flue gases and can be found in undesirable quantities in soil and water sources in the region. The water quality of an area must be evaluated regularly to ensure the quality of potable water. The present study evaluates the pre-monsoon and post-monsoon concentrations of several important physico-chemical parameters and heavy-metal contents of groundwater samples collected from sites near the Koradi Thermal Power Plant, a major source of power generation in the Nagpur Region. The maximum amount of total dissolved solids observed during the two seasons studied were 1571 mg/l and 1591 mg/l which is within the desirable limit implying that fly ash contamination did not affect this water quality parameter. The total hardness of samples from GW-3, GW-5 and GW-9 were 844 mg/l, 775 mg/l and 675 mg/l during pre-monsoon season, while GW-3 and GW-5 along with GW-4 continued to show high levels of total hardness at 1015 mg/l, 741 mg/l and 650 mg/l, respectively. These values are higher than the permissible limit due to the high levels of ions of bicarbonate, calcium, sodium and sulphate derived from fly ash leachate. Statistical analysis showed that sulphides, total hardness, electrical conductivity and total dissolved solids were the significant water quality parameters of the region. The evaluation of the parameters found that the three water sources (GW-3, GW-5 and GW-9) out of 10 are the most affected groundwater sources of fly ash pollution.

Microalgae: A Way Forward Approach Towards Wastewater Treatment and Bio-Fuel Production

Abstract: Alternative sources of energy are being favored over conventional sources to reduce the amount of pollution and to lower the dependency on fossil fuels. Microalgae can be used as an effective way to treat wastewater and the subsequent generation of bio-fuel. The aim of this chapter is to study some of the important parameters of advanced wastewater treatment using algae and the use of algal biomass as a source of energy. Wastewater is desirable as a culture medium for microalgae species due to its richness in essential nutrients like carbon, nitrogen and phosphorus, its ease of availability, and inexpensive nature. Microalgae have great potential as a feedstock for bio-fuel production due to their rapid growth rate and high lipid content. Biofuel is an attractive option because it is a clean fuel and is less toxic to the environment. Effective treatment of wastewater leads to the removal of nitrogen, phosphorus, and emerging organic contaminants (EOC). The harvesting of microalgae biomass after treatment is a crucial step in determining the cost of the biodiesel. Efficient harvesting methods include flocculation and floatation. Many countries, such as the USA, Mexico, and Taiwan, have used microalgal cultures for the treatment of wastewater and in biodiesel production.

Strategies for optimization of microbial community structure in microbial fuel cell for advanced industrial wastewater treatment

Abstract: Microbial fuel cells (MFCs) are increasingly being used for the bioremediation of pollutants discharged from the industries They provide the convenience of generating electricity using low-cost wastewater media Many structural and functional parameters of MFCs have been modified to obtain enhanced power generation and pollutant removal However, the electron producing ability of microorganisms has not increased significantly over the years This chapter emphasizes on the selection of the type of wastewater, microorganisms, and operating parameters to achieve increased power generation A combination of different bacterial communities, including nitrifying bacteria, denitrifying bacteria, electrochemically active bacteria, sulfate-reducing bacteria, and phosphorus-accumulating bacteria, have been found to generate electrons in MFC These microorganisms are majorly impacted by the nature of wastewater used and the environmental conditions provided for their growth in the media

Formation mechanism and applications of cenospheres: a review

Abstract: In thermal power plants, pulverized coal combusts to give an intricate composition of anthropogenic materials such as fly ash (coal). These materials are a major threat to environmental (air and water, etc.) pollution if dispose of to landfill sites and rivers. Since the last two decades, research and efforts are going on to reduce production and derivation of potentially valuable materials from coal fly ash such as cenosphere. Cenosphere is a low density, chemically inert and spherical material filled with air/inert gas (either nitrogen or carbon dioxide). Cenosphere is considered to be the most important fraction of fly ash as it is being used in different industries due to its condescending properties such as high workability, thermal resistance, compressive strength and low conductivity, bulk density. This review discuses the extraction of cenosphere from fly ash, its characterization (physical and chemical) and applications in different industries.

Synthesis and Characterization of Amorphous Iron Oxide Nanoparticles by the Sonochemical Method and Their Application for the Remediation of Heavy Metals from Wastewater.

Abstract: Nanoparticles have gained huge attention in the last decade due to their applications in electronics, medicine, and environmental clean-up. Iron oxide nanoparticles (IONPs) are widely used for the wastewater treatment due to their recyclable nature and easy manipulation by an external magnetic field. Here, in the present research work, iron oxide nanoparticles were synthesized by the sonochemical method by using precursors of ferrous sulfate and ferric chloride at 70 °C for one hour in an ultrasonicator. The synthesized iron oxide nanoparticles were characterized by diffraction light scattering (DLS), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), electron diffraction spectroscopy (EDS), high-resolution transmission electron microscopy (HRTEM) and vibrating sample magnetometer (VSM). The FTIR analysis exhibits characteristic absorption bands of IONPs at 400–800 cm−1, while the Raman spectra showed three characteristic bands at 273, 675, and 1379 cm−1 for the synthesized IONPs. The XRD data revealed three major intensity peaks at two theta, 33°, 35°, and 64° which indicated the presence of maghemite and magnetite phase. The size of the spherical shaped IONPs was varying from 9–70 nm with an average size of 38.9 nm while the size of cuboidal shaped particle size was in microns. The purity of the synthesized IONPs was confirmed by the EDS attached to the FESEM, which clearly show sharp peaks for Fe and O, while the magnetic behavior of the IONPs was confirmed by the VSM measurement and the magnetization was 2.43 emu/g. The batch adsorption study of lead (Pb) and chromium (Cr) from 20% fly ash aqueous solutions was carried out by using 0.6 mg/100 mL IONPs, which exhibited maximum removal efficiency i.e., 97.96% and 82.8% for Pb2+ and Cr ions, respectively. The fly ash are being used in making cements, tiles, bricks, bio fertilizers etc., where the presence of fly ash is undesired property which has to be either removed or will be brought up to the value of acceptable level in the fly ash. Therefore, the synthesized IONPs, can be applied in the elimination of heavy metals and other undesired elements from fly ash with a short period of time. Moreover, the IONPs that have been used as a nanoadsorbent can be recovered from the reaction mixture by applying an external magnetic field that can be recycled and reused. Therefore, this study can be effective in all the fly ash-based industries for elimination of the undesired elements, while recyclability and reusable nature of IONPs will make the whole adsorption or elimination process much economical.

Sustainable application of cenospheres in cementitious materials – Overview of performance

Abstract: Cenospheres are waste products generated from the production of power from coal combustions. These wastes can be incorporated into cementitious materials to produce lightweight materials. In addition, the incorporation of these wastes can be used to improve the thermal and acoustic properties of cementitious materials. However, the incorporation of these cenospheres alters other properties. Hence, it is critical to understand how the incorporation of cenospheres into cementitious composites affects various properties. This paper presents a critical review of the properties of cementitious materials incorporating cenospheres. A brief discussion on the source, physical properties and chemical properties of cenospheres were first made. The effect of cenospheres on the physical, mechanical and durability was also discussed. The discussion made in this paper showed that the cenospheres can be incorporated into cementitious materials to produce lightweight materials and enhance the thermal and acoustic properties.

Enhanced soil fertility, plant growth promotion and microbial enzymatic activities of vermicomposted fly ash.

Abstract: It is reported that coal consumption in the Asia-Pacific region is going to increase to about 87.2 percent by 2035. Management of coal combustion residues (CCRs) generated by industries is a major bottleneck towards handling the repercussions of coal usage. The present study investigates a management technique for these potentially hazardous wastes by means of vermicomposting. In the present investigation, studies were made on the effects of various concentrations of vermicomposted fly ash (VCF) added to agricultural soil, on the growth and yield of tomato (Lycopersicon esculentum Mill.) and brinjal (Solanum melongena L.) plants. The toxicity of trace elements in VCF were estimated using coefficient of pollution and potential ecological risk index, which revealed no apparent risks to the environment. A gradual increase in VCF concentrations in the agricultural soil improved the physico-chemical properties, enzymatic activities, microbial biomass, carbon and microbial population upto 90 days after sowing of seeds. The VCF amendments significantly (p < 0.05) improved the soil quality (2.86% nitrogen and 1.05% Phosphorous) and germination percentage (82.22%) of seeds in L. esculentum and also in S. melongena. The results of this study reveal that, CCRs can be effectively managed in agriculture specially in developing economies.

Microalgae harvesting by fungal-assisted bioflocculation.

Abstract: Although the production of biofuels from microalgae has numerous advantages over other raw materials, its large-scale application still comes across economic aspects. In this context, the concept of biorefinery emerges as a strategy to increase the sustainability of this process. Studies have been developed to reduce production costs, especially to optimize the harvesting stage. Among the techniques used, bioflocculation is a promising alternative to traditional harvesting methods, as it is viable in terms of cost, execution and efficiency and, above all, it is a more environmentally appropriate method. This study aimed to perform a bibliometric and systematic review of traditional algal harvesting techniques and the mechanisms governing the different interactions of microorganisms used as bioflocculants, especially fungi. The high efficiencies of microalgae harvesting, combined with the possibility of cultivation in wastewater and the various bioproducts originated from this biomass, show the potential application of bioflocculation in the context of integrated biorefineries.