Department of Environmental and Water Resources Engineering

Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

&nbsp;

&nbsp;

VIT University

School of Civil Engineering

Sustainable resources management, incorporating energy markets and resources such as electricity, fossil fuels, renewable and sustainable energy capital is essential for society to understand production and conversion of various forms of energy, their current as well as future supply. Waste-to-energy (WTE) or energy-from-waste (EFW) is a well-identified transitional technology which could prevent complete depletion of renewable resources. In our present study, the selected microalgae (Chlorella pyrenoidosa) was cultured in paddy-soaked wastewater (PWW) using outdoor raceway ponds of 50 L capacity where biotransformation of nutrients (NH3–N removal: 75.89 ± 0.69%; PO4–P removal: 73.71 ± 0.75%; yield co-efficient YN: 6.12 mg biomass/mg of N; YP: 7.77 mg biomass/mg P) has occurred with better growth and biochemical composition (dry biomass weight: 1.56 ± 0.11 g/L; chlorophyll: 15.57 ± 0.14 mg/L; specific growth rate (SGR): 0.42/d; lipids: 27.47 ± 1.41% biomass; carbohydrates: 23.77 ± 1.00% and protein: 46.12 ± 3.55%). Further, the obtained algal lipid was identified for a wide range of fatty acid methyl esters (FAME) and consequently brought forward to in-situ single-step transesterification by optimizing reaction conditions. Central composite design (CCD) of response surface methodology (RSM) has given optimized conditions of sample amount: 2 g (wet); methanol sulphuric acid volume: 3 mL; and hexane volume: 4 mL, under the reaction temperature of 90 °C for maximum biodiesel conversion (46.54% of algal lipids). The outcome of our current research may add value to the application and development of WTE technology for sustainable energy conservation. © 2020 Elsevier Ltd

World University root node

CO2 Research and Green Technologies Centre

Vellore Campus

Biomass and Bioenergy

Outdoor cultivation of Chlorella pyrenoidosa in paddy-soaked wastewater and a feasibility study on biodiesel production from wet algal biomass through in-situ transesterification

In the present research, characterization of ancient lime mortar from the 300-year-old Renukadevi Temple at Chandragutti, Karnataka, India, was carried out to propose an appropriate repair procedure for fixing a water leakage through the roof slab. The reason for the water seepage was a poor binder with the aggregate, with a ratio of 1:7. When the lime was washed away due to intense rain, the mortar became porous. XRD indicated that the original structure contains hydraulic lime with mineral-rich clay including calcite, aragonite, vaterite and tobermorite. The presence of tobermorite results in good performance and durability of the structure. The presence of organics rich in carbohydrate and protein was indicated by the FT-IR results. The repair mortar was simulated with an Oxal VP IT injection grout with 5 % of fermented kadukkai and jaggery as carbohydrate-rich organic sources. The rheological performance of the organic grout was good during Marsh-cone and stability test. After 28 days, the compressive strength of the 1:3 mortar was 1.13 N/mm2, suggesting it behaved like an artificial pozzolanic mortar with good strength. The organics played the main role in the carbonation of lime mortar and precipitation of tobermorite. A new organic grout compatible with the old mortar of the structure was prepared for the restoration. © 2020

Department of Structural and Geotechical Engineering

Fulltext

Materiali in Tehnologije

GROUTING AND INJECTION TECHNIQUES TO REPAIR CRACKS AND WATER LEAKAGE AT THE RENUKA DEVI TEMPLE, CHANDRAGUTTI, INDIA [POPRAVLJANJE RAZPOK S TEHNIKAMI OMETAVANJA IN NABRIZGAVANJA V TEMPLJU RENUKA DEVI, CHANDRAGUTTI, INDIJA]

Landfills are highly engineered waste containment systems, designed to minimize the impact of waste on the environment. In modern landfills, the waste is contained by liner and cover systems. Due to the scarcity of natural clay, the commercially available bentonite is often used in the construction of liners. The bentonite layer generally shrinks during the summer, and therefore, severe cracks are formed; thus, it fails to control the migration of leachate. In the past, various additives have been used to stabilize bentonite. In recent years, studies have been focused on using reactive materials as additives so that they can stabilize bentonite, and also, it can adsorb the heavy metals from the leachates. The sugar industry produces fly ash, known as the bagasse ash, which causes a disposal problem. This bagasse ash is found to be a good absorbent material. Hence, a study was carried out to assess the stabilization of compacted clay liner blended with bagasse ash. Several tests, including consistency limits and hydraulic conductivity tests, have been performed by blending different contents of bagasse ash. From the test results and their analysis, it is observed that 40% of bagasse ash can be mixed with bentonite so that the essential requirements of the liner are maintained. © Springer Nature Switzerland AG 2020.

Lecture Notes in Civil Engineering

Utilization of bagasse ash in the compacted clay liner

Nanoscale zero-valent iron (nZVI) particles have proved to be effective in the remediation of chlorinated compounds and heavy metals from contaminated soil. The present study aimed to analyze the performance of nanoparticles synthesized from low-cost biomass (green leaves) as chemical precursors, namely Azadirachta indica (neem) and Mentha longifolia (mint) leaves. These leaves were chosen because huge amounts of them are present in the region of Vellore. These nanoparticles were used to remove lead and nickel from contaminated soil. Characterization of nZVI particles was conducted using the Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), and Brunauer–Emmett–Teller isotherm (BET) techniques. Remediation was performed on two different soil samples, polluted with lead or nickel at an initial metal concentration around 250 mg/kg of soil. The results revealed that after 30 days, the lead removal efficiency with 0.1 g of nZVI particles/kg of soil was 26.9% by particles synthesized using neem leaves and 62.3% by particles synthesized using mint leaves. Similarly, nickel removal efficiency with 0.1 g of particles/kg of soil was 33.2% and 50.6%, respectively, by particles using neem and mint leaves. When the nanoparticle concentration was doubled, Pb and Ni removal improved, with similar trends obtained at a lower dosage (0.1 g of particles/kg of soil). These first results evidenced that: (1) the nZVI particles synthesized using green leaves had the potential to remove Pb and Ni from contaminated soil; (2) the neem-derived particles gave better Pb removal efficiency than Ni one; (3) the mint-derived particles showed better Ni removal efficiency than Pb one; (4) the highest removal efficiency for both metals was achieved with the mint-derived particles; (5) double higher dosage did not greatly improve the results. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.

Department of Thermal and Energy Engineering

School of Mechanical Engineering

Processes

Remediation of lead and nickel contaminated soil using nanoscale zero-valent iron (Nzvi) particles synthesized using green leaves: First results

Protein-functionalised aluminium nanosheets (PRS–AlNs) were packed in a continuous fixed-bed column to remove crystal violet (CV) and Congo red (CR) dyes. A group of characterisation techniques, like SEM, TEM, AFM, XRD, BET, DSC and Raman spectroscopy, was performed for PRS–AlNs. The influence of several factors like bed depth (1, 2 and 3 cm), inlet dye concentration (50, 100 and 150 mg/L) and inlet flow rate (1.17, 2.26 and 3.34 mL/min) on the characteristics of the breakthrough profile of the adsorption process was examined at optimum pH 9.8 and 3.5 for CV and CR, respectively. The maximum adsorption capacity was achieved as 38.70 and 57.86 mg/g for CV and CR at 1 cm bed depth, 150 mg/L inlet concentration of the dye and 3.34 mL/min inlet rate of flow. The experimental data were analysed using kinetic models like the Yoon–Nelson, Adams–Bohart and Thomas models. Also, a detailed mechanism behind the CV and CR adsorption using PRS–AlNs was proposed in this research work. [Figure not available: see fulltext.]. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.

VIT Unitversity

Environmental Science and Pollution Research

Application of protein-functionalised aluminium nanosheets synthesised from sewage sludge for dye removal in a fixed-bed column: Investigation on design parameters and kinetic models

This paper reviews the current state of the art performance of Graphene Oxide (GO) and Reduced Graphene Oxide (rGO) addition in cement composites. GO has regarded as an excellent Nano-filler in cement composites by the extraordinary properties. In this study, performance aspects such as workability, durability, mechanical and microstructural characteristics of GO reinforced cement composites were reviewed. Interaction of GO with several mineral admixtures such as fly ash, silica fume and geopolymer composites in an admixed cement system was comprehensively discussed. This is the first paper to review GO performance with various mineral admixtures and to discuss and distinguish performance rGO in cement composites. Effects of reducing oxygen functional groups while producing rGO and the performance of rGO have been elaborated. rGO reinforcement in cement composites possesses a new research direction. Enhancements and drawbacks by reinforcing GO and rGO were reviewed till date. Recent extensive research on the performance of GO-cement composites has reviewed to transform conventional cement materials into smart, strong, and durable composites. This review provides an overview of performance, recent developments and fabrication of GO-cement composites in enhancing mechanical performance, durability, of cement composites. Concluding remarks stated indicating challenges and future perspectives on how to effectively use GO as a Nano-reinforcing material in cement composites. © 2020 Elsevier Ltd

Construction and Building Materials

An intense review on the performance of Graphene Oxide and reduced Graphene Oxide in an admixed cement system

Clays are used for the construction of waste containment barriers, because of its low hydraulic conductivity. Due to the difficulty in obtaining the natural clay satisfying the essential requirement as a liner material; commercially available bentonites are being used for the construction of clay liners. Bentonite undergoes large volume changes upon saturation. Various physical and chemical stabilisation techniques are in practice to stabilise the bentonite. Previous studies reported that contaminants with high concentrations attack clay minerals leading to increase in their permeability. Exfoliated vermiculite, finds several applications in construction industry, also found to be good absorbent material. Hence, this study has been carried out to find the optimal percentage of vermiculite that can be added to the bentonite so that it satisfies the essential requirements of clay liners and absorb the heavy metals from contaminants. Several index properties and engineering properties tests on bentonite-vermiculite mixtures were performed. From the studies, it was found that 30% of vermiculite can be added to bentonite, so that the essential requirements of liner can be maintained. Copyright © 2020 Inderscience Enterprises Ltd.

International Journal of Environment and Waste Management

Hydraulic and volume change characteristics of compacted clay liner blended with exfoliated vermiculite

Increase in sludge dewatering plays an important role in reducing its treatment, handling and disposal costs. In this work, efficacy of various sludge dewatering techniques such as Fenton (F), Free Nitrous Acid (FNA) and F/FNA was performed under ultrasonication. Experiments were carried out to determine the amount of sludge filtrate and Capillary Suction Time (CST) under various conditions. The optimum pH was found to be 3, 3 and 5 respectively for Fenton, FNA and F/FNA. More amount of sludge filtrate was detected for treated sludge in the order F/FNA (57 mL) &gt; FNA (55 mL) &gt; Fenton (48 mL) and minimum CST was observed in F/FNA (28 s) &lt; FNA (31 s) &lt; Fenton (49 s). SEM and DSC analysis were performed to observe the variation in physical characteristics before and after treatment. The change in functional groups in sludge cake before and after treatment was investigated using FT-IR. Excitation-Emission Matrix (EEM) was used to measure the fluorescence peak and intensities of the released biopolymers into sludge filtrate caused by the disintegration of EPS. In addition, the radical scavenging experiments were also performed to identify the significant roles of hydroxyl (OH·), nitrogen dioxide (NO2 ·), nitric oxide (NO·) and superoxide (O2 ·-) radicals. The experimental results indicated that the increased mass transfer due to the application of ultrasonication resulted in higher dewaterability. The leaching of metals from the sludge cake into the treated sludge filtrate portrays that sludge could be utilized as manure and solid biomass fuel. © 2019 Elsevier B.V.

Chemical Engineering Journal

A study on combined effect of Fenton and Free Nitrous Acid treatment on sludge dewaterability with ultrasonic assistance: Preliminary investigation on improved calorific value

Assessing information on climate change over a regional scale is made possible through general circulation models (GCMs). However, developers generally have a dilemma in selecting suitable GCM for regional scale downscaling to reduce the computational burden. Ranking of GCMs based on various conditions will help these purposes, and the present study evaluates the performance of GCMs using various performance evaluation parameters for ranking. Performance of twenty-six Coupled Model Intercomparison Project Phase 5 (CMIP5) GCMs was assessed in the present study to evaluate and rank the predictability of near-surface air temperature (tas) and precipitation (pr). The non-parametric trend existing in observed data from 35 stations is compared with GCM projected trends using Mann-Kendall trend analysis to assess the model reliability. Performance evaluation parameters such as percentage BIAS (PBIAS %), normalized root mean squared error (NRMSE %) and coefficient of determination (R2). Neither of the CMIP5 GCM performed consistently well throughout all four seasons. Also, models performing better in projecting temperature statistics are poor in capturing the precipitation trends and vice versa. The seasonal ranking of GCMs based on their ability to reproduce the regional weather condition would help in selecting suitable GCM for regional climate studies. © 2020, Saudi Society for Geosciences.

Arabian Journal of Geosciences

Assessment and ranking of CMIP5 GCMs performance based on observed statistics over Cauvery river basin – Peninsular India

This research is part of a wider scientific Italian-Indo project finalised to shed lights on pottery fabrication and trade circulation in Tamil Nadu region during Early Historical Period. The recent archaeological excavations carried out in Alagankulam—a famous harbour trading with the eastern and western world—and in Keeladi—the most ancient civilization centre attested in Tamil Nadu region—provided numerous fragments of archaeological ceramics. The typological analysis enabled the identification of different pottery classes, suggesting the presence of local productions, possible imports and imitations. Studied shards included common Indian vessels, fine wares and luxury ware repertoire. The provenance identification of some of the studied typologies is still debated in the literature; for long time, the misattribution of several ceramic classes has led to wrong interpretations on the commercial connections between India and the Western and Eastern Mediterranean area. The minero-petrographic and spectroscopic investigation of several ceramic fragments from the two investigated archaeological sites enabled the systematic compositional characterization of specific ceramic classes both locally manufactured and imported. The obtained results contributed to draw short-range and long-range connections in Tamil Nadu area. © 2020, The Author(s).