Faculty Publications
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Item Development in groundwater treatment - Indian perspective(IWA Publishing, 2016) Thalla, A.K.; Devatha, C.P.[No abstract available]Item Technologies for ground water treatment: Pump-and-treat technologies(IWA Publishing, 2016) Thalla, A.K.; Devatha, C.P.; Daronco, G.C.[No abstract available]Item Green Synthesis of Nanomaterials(Elsevier, 2018) Devatha, C.P.; Thalla, A.K.The nanotechnology industry is increasingly promoting nano as a “green” technology that will improve the environmental performance of existing industries, reduce consumption of resources and energy, and allow achievement of environmentally benign economic expansion. Eco-friendly solutions are gaining popularity in the contemporary world. A green method for nanoparticle synthesis should be assessed considering three aspects: the solvent, the capping agent, and the reducing agent compared to physical and chemical methods. Particularly, the plant extracts mediated process is a good and advantageous method for the development of metal nanoparticles compared to using microorganisms, in which the cell maintenance time is limited. Synthesis and characterization of nanoparticles are important steps to be adopted to apply nanoparticles in field applications, and these steps include preparation of leaf extract, Phytochemical screening, and preparation of precursor. Various factors affecting the synthesis of nanoparticles, such as pH, temperature, and time, will be discussed. The degradation of any organic compounds by the green approach (plant extracts) is mainly due to the presence of polyphenols in the biodegradable material. Although the synthesis of nanoparticles has been trending higher, their application in the area of waste water treatment has been limited until recently. Hence, the application of nanoparticles to waste water treatment will be discussed with a view toward paving the way for an alternate source of water. © 2018 Elsevier Ltd. All rights reserved.Item Enhancing the Dewatering Ability of Sludge by Locally Available Biomass(Springer Nature, 2023) Chopade, G.; Devatha, C.P.In this study, the effect of modified coconut shell biochar is analyzed for its efficacy achievable in sludge dewatering properties. Initially the coconut shell biochar is modified at different molar concentrations of FeCl3, i.e., 1, 2, and up to 5 mol/L, and it is analyzed with different dosages at 0.1, 0.2, and up to 0.4 (g/g of dry solids (DS)) for the improvement in capillary suction time (CST) (s), moisture content reduction (%), filterability (min), and settleability (SV30%) of the sludge. It is found that there is significant decrease in each of these parameters. The optimization study is carried out to optimize the process of sludge conditioning, considering independent regression parameters as dosage (g/g of DS), molarity (M), mixing time (min), and response taken as moisture content (%), the optimum values for the dosage, molarity, mixing time is found to be 0.4 (g/g of DS), 2.5 M and 24.72 min, respectively, with optimized moisture content value of 78% was achieved. Hence, the modified coconut shell biochar can be used as a potential candidate to increase the dewatering ability of the sludge. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023.Item Low-Cost Recovery of Cadmium from Wastewater by Soil Bacteria(Springer Nature, 2023) Kothuri, M.; Devatha, C.P.Cadmium is a toxic heavy metal with significant health and environmental concerns. It accumulates in soil and water, contaminates the food chain, and causes severe health problems, including kidney damage, anemia, and cancer. Industries involving the production of pigments, batteries, and alloys discharge wastewater containing high levels of cadmium. Hence, wastewater can serve as a valuable and viable source of cadmium, reducing the need for costly and environmentally damaging mining and refining activities. This study aims to recover cadmium from wastewater using bioprecipitation. Ureolytic bacteria from rhizospheric soil were used to separate cadmium from synthetic wastewater of different strengths. The recovery efficiency of the bioprecipitation method was more than 95%, according to the atomic absorption spectroscopy (AAS) analysis. X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) studies were conducted to identify the residue. In conclusion, bioprecipitation method has been found to be an effective and sustainable approach to recover cadmium from wastewater, making it a promising solution to economic and environmental challenges. This method is efficient, cost-effective, and easy to operate, making it suitable for in-field applications. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023.Item Recovery of phosphorus as struvite from the dewatered liquor through crystallization using seawater as magnesium source(Elsevier, 2023) Devatha, C.P.; Rashmi, H.R.Because of the finite and nonrenewable nature of the phosphate resource, recycling and reuse of nutrients is an environmental and economic motivation that finally leads to water reuse. In recent times, phosphorus recovery has been attempted using waste materials. Hence in this paper, the recovery of phosphorus was studied from the dewatered liquor using seawater as a magnesium source, using the struvite crystallization technology, which is one of the most widely recommended technologies for the recovery of phosphorus. The sludge dewaterability was achieved with varying dosages of granulated blast furnace slag as skeleton material. Initial characteristics of dewatered liquor and seawater were investigated. Batch studies were conducted with varying pH (7–11) and a molar ratio of Mg/P (0.6–1.4) to determine the optimum condition for the maximum recovery of phosphorus. Characterization studies were carried out to study morphology by scanning electron microscope, the composition of solids by Fourier transform infrared, and phase identification by X-ray powder diffraction for the confirmation of struvite formation; 94% of the phosphorus was recovered as struvite, demonstrating good phosphorus recovery capability. The goal of the study is to develop an innovative and economical method for crystallizing struvite in order to extract phosphorus from the dewatered liquid. It can be concluded that seawater can also be considered as a source of magnesium for the production of struvite. © 2023 Elsevier Inc. All rights reserved.Item Machine learning approaches for the estimation of particulate matter (PM2.5) concentration levels: A case study in the Hyderabad City, India(Springer Verlag, 2019) Krishnappa, L.; Devatha, C.P.Particulate matter concentration is one among several variables monitored at regular intervals to calculate air quality indices (AQI) which are intended to help understand the acute and chronic effects of air quality on human health. The fine particulate (PM2.5) samplers installed at pollution monitoring stations continuously monitor the concentration of pollutant in air over time. The specific time-averaged concentration is then estimated from the continuous records. Missing data records in the PM2.5 time series is quite normal, which is attributed by faulty equipment, routine maintenance schedules, or replacement of equipment. When one or more point observations in a time series are missing, it is very essential to estimate or predict the missing values. This study presents the application of machine learning techniques such as support vector regression (SVR), group method of data handling (GMDH) network, and evolutionary adaptive neuro fuzzy inference system to estimate the 24-h average PM2.5 concentration levels at a particular station using PM2.5 concentration levels observed at neighborhood stations as inputs. The performance of these models are evaluated in terms of widely used statistical metrics such as centered root mean square difference (CRMSD), normalized Nash–Sutcliffe efficiency (NNSE), and correlation coefficient (R). The findings of the study reveal that the GMDH model provided reasonably accurate estimates of daily PM2.5 levels. © Springer Nature Singapore Pte Ltd. 2019.Item Phosphorus recovery as induced struvite from deep dewatered liquors using magnesium chloride as a magnesium source(Institute of Physics Publishing helen.craven@iop.org, 2019) Rashmi, H.R.; Devatha, C.P.The phosphorus recoveries in municipal wastewater treatment plants (WWTPs) are in much demand as the price of phosphate rock are increased from the last decade. Due to the increase in pollution levels of the sewage sludge, it is difficult to use sewage sludge directly as fertilizers in agricultural fields. The present study aimed to work on the recovery of phosphorus from the deep dewatered liquors in a laboratory, batch test mode. Experiments were conducted to identify the initial characteristics of sludge and for recovery analysis, by varying the phosphorus and Magnesium (Mg:P) molar ratio. Characterization studies were performed by SEM and FTIR for confirmation of struvite formation. Results obtained revealed that recovery is 94% of the incoming phosphorus. © 2019 IOP Publishing Ltd. All rights reserved.Item Impact On Leaching Behaviour Of Toxic Metals In Ferrochrome Ash With Varying Ph Levels(American Institute of Physics Inc., 2022) Krishnamurthy, M.P.; Devatha, C.P.In the current investigation, leaching behaviour of cobalt (Co), copper (Cu), iron (Fe), zinc (Zn), calcium (Ca), arsenic (As), cadmium (Cd), chromium (Cr), mercury (Hg), nickel (Ni), lead (Pb) and selenium (Se) from fresh and aged Ferrochrome Ash (FCA) samples were studied under various pH conditions (3-11). Results reveal that most of the elements follow oxyanionic leaching pattern where increase in pH increases the effluent concentration of elements. Leached As, Pb, Hg, Ni and Fe reached peak concentration at alkaline phases. Cd, Cr and Zn followed cationic leaching pattern where increase in pH decreases the concentration. Any specified pattern of leaching is not followed by Ca, Se, Co and Cu. Results of leaching test reveal that the high concentration of chromium leaching was found to be 156.18 and 155 mg/L, concentration of arsenic 13.46 and 12.89 mg/L, concentration of mercury 10.23 and 10.4 mg/L and lead concentration of 6.58 and 6.72 mg/L for fresh and aged FCA ashes respectively. Hence Cr, As, Hg and Pb are identified as significant hazardous pollutants and must not be discharged without being solidified/stabilized. Leached element concentration was not affected significantly by aging of the FCA. © 2022 American Institute of Physics Inc.. All rights reserved.Item Entrapment of Nickel in Ferrochrome Ash by Native Lysinibacilus sp Bacteria(Avestia Publishing, 2023) Kothuri, M.; Devatha, C.P.Nickel contamination in water is a significant environmental concern and causes several health effects such as allergies, cardiovascular diseases, and cancers in human beings. Ferrochrome ash is a fine dust generated as the waste from steel industry and pollutes the flow-through water by leaching nickel present in it. By providing a pre-disposal treatment of microbial induced calcite precipitation (MICP) to ferrochrome ash, the nickel leaching can be substantially reduced. Bacteria secrete the urease enzyme that decides the rate of urea hydrolysis reaction and they are the nucleation sites for the precipitation of calcium carbonate in calcium rich environment. During MICP, calcium carbonate entraps the nickel present in the ash. As a result, the nickel cannot escape the ash matrix and hence do not pollute the contacting water. This was confirmed by the atomic absorption spectrophotometric analysis (AAS) on leachates from treated and untreated ash. The analysis resulted in less nickel content from treated ash with highest treatment efficiency of 98% at LS 100. Results from SEM, FTIR, XRD, and TG implied that calcium carbonate developed in the ash due to MICP. © 2023, Avestia Publishing. All rights reserved.