Shantini A. Bokil

Bio: Shantini A. Bokil is an academic researcher from Massachusetts Institute of Technology. The author has contributed to research in topics: Adsorption & Activated carbon. The author has an hindex of 2, co-authored 3 publications receiving 4 citations.

Adsorption of textile industry effluent in a fixed bed column using activated carbon prepared from agro-waste materials

Abstract: Activated carbon prepared from agro-waste material i.e. green coconut shell and bamboo using ZnCl2 as an activation agent in an adsorption column (fixed bed) was studied for the treatment of textile industry effluent. The experiment with the fixed-bed column was performed by different process parameters such as 200, 400 and 600 mg/L as different initial concentration of dye, at different bed heights of 100 mm, 200 mm, and 300 mm, and 10, 15, and 20 mL/min as different flow rates. The findings demonstrated that both breakthrough and exhaust times increase, with the height of the bed being increased, but decrease with the concentration of the dye inlet. The breakthrough point was found to depend upon the bed height and flow rate. The maximum uptake capacity was obtained when a 200 mm bed depth was used at an inlet concentration of dye 200 mg/L with a flow rate of 15 mL/minute. It was observed that the bamboo activated carbon BAC has high carbon content, and has a high potential for dyes removal and may become capable substitutes for costly activated carbon. The adsorption capacities of BAC, GCSAC are at par with respect to each other, the overall process scheme may become economical as these materials are available as wastes and practically free of cost.

Batch Adsorption Studies on Treatment of Textile Industry Effluent using Bamboo and Green Coconut shell Activated Carbon

Abstract: The use of activated carbon (AC) as a strong adsorbent was commonly used. This work deals with the study of textile industry wastewater (dye) adsorption on AC produced from Bamboo and Green coconut shell through chemical activation method. The effect of various process parameters such as the amount of adsorbents, initial concentration of dye, pH, contact time, temperature and agitation speed on percentage removal of dye on the activated carbon i.e. Bamboo activated carbon (BAC) and Green Coconut Shell Activated carbon (GCSAC) batch adsorption tests were investigated. Testing was performed for quantitative description of Langmuir and Freundlich equilibrium adsorption isotherms. Based on the experimental findings, the equilibrium was observed in 6 hours. Langmuir isotherm was the best suited for the adsorption of dye, with a maximal adsorption capacity of 142.86 mg / gm. The removal of dye by the use of BAC has been found to be greater than GCSAC.

Nano-metal oxides-activated carbons for dyes removal: A review

Abstract: It is common for dyes to be utilized in a wide range of industries such as leather and textiles as well as the printing, paper, and packaging industry. Most dyes fall into a dangerous category of water toxins that have had a significant impact on the ecosystem. Dye removal from wastewater can be done in a variety of methods. It is now necessary to develop advanced and cost-effective methods. Organic dyes may be removed from textiles using adsorption, which is a more effective and environmentally beneficial process. Nanomaterials are a more attractive option for dye removal because of their unique characteristics. An approach to the synthesis, characterization, and dye removal capabilities of nano-metal oxides-activated carbons is presented. This review also includes a discussion of several operating parameters associated with the adsorption process, adsorption isotherms, kinetics, thermodynamic behavior, and reusability of the adsorbent.

An overview of antimicrobial nanoparticles for food preservation

Abstract: Nanotechnology opens up new possibilities for food innovation at an incredible rate, yet new technology needs evaluations of both potential negative impacts and numerous good effects. We aimed to cover some of the latest breakthroughs in nanotechnology and their application to food processing in this overview. Applications of nanoparticles in the food sector are growing rapidly. Nanoparticles (NPs) play a significant role in enhancing food quality by protection and preservation and are preferred over traditional preservatives. In this work on organic and inorganic nanoparticles in various forms such as single and multiple metal oxides, polymeric nanocomposite, nanocapsules, etc., as well as various methods of their preparations are discussed. Nanoparticles in food are currently most explored for their antimicrobial applications; factors affecting their antimicrobial potential, their antimicrobial mechanisms, and laboratory methods applied to evaluate antimicrobial potentials are also discussed. Various properties of NPs in relevance to antimicrobial activities and methods used for their characterization are also discussed. Antimicrobial NPs used for the purpose in various ways such as active packaging, mixed in food, incorporated in edible film and coating, etc. discussed. In the current state NPs used in the food industry, have various concerns such as safety, and regulatory policies relevant to preparing, processing, packaging, and consumption are discussed. NPs do possess some functional properties and harmful effects as well in this relevant future perspective of antimicrobial NPs in food and their other applications explored in current work. Various aspects of the most intensively studied NPs as an antimicrobial in food technology such as silver oxide, and zinc oxide, are discussed.

Removal of Methylene Blue Using Activated Carbon Prepared from Waste Fruit (Orange) Peels

Abstract: Many industries such as cloth, paper, leather, plastic, and so on produce a significant amount of wastewater with color for a day now. The presence of dye materials has a direct effect on water quality, and the elimination of this form of pollutant is of prime importance. Activated orange peel carbon was prepared and used to extract methylene blue (MB) from aqueous solutions. The impacts of different factors were examined, such as adsorbent concentration (0.2, 0.4, 0.6, 0.8, 1.0 g/L), initial MB concentration (100, 200, 300, 400 ppm), temperature (40, 50, 60 ℃), contact time (10, 20, 30, 40, 50, 60 min.), and pH (3, 5, 7, 9, 11). Maximum adsorption has been found to occur at an adsorbent concentration of 0.8 g/L, a dye concentration of 100 ppm, a contact time of 50–60 min, and a Ph of 11. The experimentally collected data were analyzed by a comparative study with commercial activated carbon (CAC), and it can be concluded that activated carbon prepared from orange peel gives a higher percentage of removal as compared to commercial activated carbon at 100 ppm, 60 ℃, 0.8 g/L adsorbent, and pH 11. Results of this study showed that activated carbon made of orange peels could be used as an adsorbent to effectively remove MB from aqueous solutions.

Circular economy for fashion industry: Use of waste from the food industry for the production of biotextiles

Abstract: In the context of current environmental, social and economic issues, it is imperative to perform more in-depth studies on waste management and the life cycle of a product. Thus, the concept of circular economy, aimed at transforming traditional patterns of production and economic growth, is extremely important. One way to mitigate negative environmental impacts that is consistent with a circular economic system is to encourage interdisciplinarity between sectors, that is, one production sector can provide a function for waste from another. In this context, this article gathers scientific information on two sectors relevant to the global economy (textiles and food), with the aim of reusing waste from the food industry to manufacture a new textile product with added value. Specifically, the focus is on the use of bacterial cellulose from the probiotic drinks from kombucha, for the manufacture of biotextiles for fashion industry. A discussion is also presented, relating the circular economy concept to the UN Sustainable Development Goals, in order to understand which goals can be achieved with this approach.

A comprehensive review on the synthesis, performance, modifications, and regeneration of activated carbon for the adsorptive removal of various water pollutants

Abstract: Rapid urbanization has led to the generation of a large quantum of complex wastewater comprising of recalcitrant organic and inorganic pollutants. The inability of the conventional treatment techniques to bring down the recalcitrant pollutant concentrations below desired standards has paved the way for the emergence of tertiary treatment technologies. Among various tertiary treatment techniques, adsorption is widely preferred due to the ease of operation, high removal performances, and diverse on-field applications. Activated carbon (AC) has found immense popularity due to easy synthesis routes, high stability, large specific surface area (SSA), etc. The synthesis and performance of AC derived from different carbonaceous precursors for pollutants removal, the role of activation techniques, pollutant specific modifications, regeneration techniques, and their disposal, are covered in this article. Trend analysis showed that research on AC derived from agricultural waste and sludge has a high potential for at least another 50 and 25 years, respectively. Most of the precursors are chemically activated to prepare the AC, which may be further modified using the metal impregnation technique for removing specific pollutants. Among various ACs, maximum mean pore volume has been shown by sludge-based AC (1.17 cm3/g) and the maximum mean SSA value has been exhibited by husk-based AC (1339 m2/g). AC is mostly used to treat dyes and metals, followed by pharmaceuticals, pesticides, and other recalcitrant organics. Moreover, by implementing microwave-assisted and biological-based regeneration techniques, the life of the AC can be increased and may serve as an efficient adsorbent for wastewater treatment for a prolonged duration.

Bench-Scale Fixed-Bed Column Study for the Removal of Dye-Contaminated Effluent Using Sewage-Sludge-Based Biochar

Abstract: Batik industrial effluent wastewater (BIE) contains toxic dyes that, if directly channeled into receiving water bodies without proper treatment, could pollute the aquatic ecosystem and, detrimentally, affect the health of people. This study is aimed at assessing the adsorptive efficacy of a novel low-cost sewage-sludge-based biochar (SSB), in removing color from batik industrial effluent (BIE). Sewage-sludge-based biochar (SSB) was synthesized through two stages, the first is raw-material gathering and preparation. The second stage is carbonization, in a muffle furnace, at 700 °C for 60 min. To investigate the changes introduced by the preparation process, the raw sewage sludge (RS) and SSB were characterized by the Brunauer–Emmett–Teller (BET) method, Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy. The surface area of biochar was found to be 117.7 m2/g. The results of FTIR showed that some functional groups, such as CO and OH, were hosted on the surface of the biochar. Continuous fixed-bed column studies were conducted, by using SSB as an adsorbent. A glass column with a diameter of 20 mm was packed with SSB, to depths of 5 cm, 8 cm, and 12 cm. The volumes of BIE passing through the column were 384 mL/d, 864 mL/d, and 1680 mL/d, at a flow rate of 16 mL/h, 36 mL/h, and 70 mL/h, respectively. The initial color concentration in the batik sample was 234 Pt-Co, and the pH was kept in the range of 3–5. The effect of varying bed depth and flow rate over time on the removal efficiency of color was analyzed. It was observed that the breakthrough time differed according to the depth of the bed and changes in the flow rates. The longest time, where breakthrough and exhausting points occurred, was recorded at the highest bed and slowest flowrate. However, the increase in flow rate and decrease in bed depth made the breakthrough curves steeper. The maximum bed capacity of 42.30 mg/g was achieved at a 16 mL/h flowrate and 12 cm bed height. Thomas and Bohart–Adams mathematical models were applied, to analyze the adsorption data and the interaction between the adsorption variables. For both models, the correlation coefficient (R2) was more than 0.9, which signifies that the experimental data are well fitted. Furthermore, the adsorption behavior is best explained by the Thomas model, as it covers the whole range of breakthrough curves.

Adsorption isotherm studies of Methylene blue using activated carbon of waste fruit peel as an adsorbent

Abstract: The presence of dye materials has a direct effect on water quality and the elimination of such pollutants is of prime importance. In this study, activated carbon was prepared using waste fruit peels (orange), and the experiments were conducted in order to determine the uptake of methylene blue (MB) by the activated carbon of waste fruit peels (orange). Batch adsorption experiments were performed to study the effect of several experimental parameters such as adsorbent dose (0.2, 0.4, 0.6, 0.8, 1.0 g/L), initial MB concentration (100, 200, 300, 400 ppm), temperature (40, 50, 60℃), contact time (10, 20, 30, 40, 50, 60 min.) and pH (3, 5, 7, 9, 11). Maximum adsorption of MB has been obtained at an adsorbent dose of 0.8 g/L, a dye concentration of 100 ppm, temperature of 60 °C and a pH of 11. The Langmuir and Freundlich isotherms were used to fit the equilibrium data and the Langmuir isotherm model with 142.86 mg/g at 60℃ best described the equilibrium data. Activated carbon made from waste fruit peels (orange) was found to be effective for removing MB from aqueous solutions. According to the findings of this investigation, natural adsorbents such as activated carbon from orange fruit peel powder can be used as an adsorbent material due to its selectivity for the removal of MB from an aqueous solution.

Preparation and characterization of activated carbon from agricultural wastes and their ability to remove chlorpyrifos from water

Abstract: Chlorpyrifos is an organophosphate insecticide linked to neurological dysfunctions, endocrine disturbance, cardiovascular illness, genotoxicity, histopathological abnormalities, immunotoxicity, and oxidative stress. Therefore, the aim of this study was to prepare activated carbon from agricultural waste to adsorb and remove chlorpyrifos from aqueous solutions, as well as to study the physicochemical characteristics of the prepared activated carbon.Activated carbon was prepared from agricultural waste (banana peels, orange peels, pomegranate peels and date stones). The activated carbon prepared showed an exterior surface that was irregular and full of cavities with Brunauer-Emmett-Teller(BET) surface areas of 94.26, 111.75, 183.89, and 289.86 m2/g for activated carbon prepared from orange peels, date stone, pomegranate peels, and banana peels respectively. The Scanning Electron Microscope (SEM) image revealed that the activated carbon's exterior surface was irregular and full of various shapes and sizes of cavities.The Energy Dispersive X-Ray (EDX) indicated the existence of carbon, oxygen, silicon and potassium in banana peels-derived activated carbon, whereas carbon, oxygen, silicon and potassium, in addition to aluminium, were detected in the pomegranate peels-derived activated carbon. The Fourier-Transform Infrared Spectroscopy (FTIR) analysis of prepared activated carbon revealed several functional groups, including carboxylic acid, carbon dioxide, and aromatic compounds. Results also showed that the activated carbon significantly removed chlorpyrifos from water, recording 97.6%, 90.6%, 71.48%, and 52.00 % for activated carbon prepared from pomegranate peels, banana peels, date stones and orange peels, respectively. The study concluded that agricultural waste-derived activated carbon could be employed as an alternative pesticide adsorbent.