Rita Dhodapkar - Academia.edu (original) (raw)

Papers by Rita Dhodapkar

Environmental Science and Pollution Research, Jan 7, 2021

Pharmaceuticals and personal care products (PPCPs) do not have standard regulations for discharge... more Pharmaceuticals and personal care products (PPCPs) do not have standard regulations for discharge in the environment and are categorized as contaminants of emerging concern as they pose potential threats to ecology as well as humans even at low concentrations. Conventional treatment processes generally employed in the wastewater treatment plants are not adequately engineered for effective removal of PPCPs. Identifying cost-effective tertiary treatment is therefore, important for complete removal of PPCPs from wastewater prior to discharge or reuse. Present study demonstrates adsorption using granular-activated carbon (GAC) as a possible tertiary treatment for simultaneous removal of five PPCPs from aqueous media. Adsorbent was characterized in terms of morphology, surface area, surface charge distribution, and presence of functional groups. Performance of GAC was investigated for sorption of three hydrophilic (ciprofloxacin, acetaminophen, and caffeine) and two hydrophobic (benzophenone and irgasan) PPCPs from aqueous solution varying the process parameters (initial concentration, adsorbent dose, pH, agitation time). Langmuir isotherm model (correlation coefficients (R2): 0.993 to 0.998) appeared to fit the isotherm data better than Temkin isotherm model for these adsorbates. Adsorption efficiencies of these compounds (8.26 to 20.40 mg g−1) were in accordance with their log Kow values. While the adsorption kinetics was best explained in terms of a pseudo-second-order kinetic model, the data suggested that adsorption mechanism was mainly governed by the intraparticle diffusion. The role of physical factors like molecular volume, molecular size, and area of targeted PPCPs were investigated through computational studies which in turn can help predicting their uptake onto GAC.

Royal Society of Chemistry eBooks, 2022

Journal Of The Chinese Advanced Materials Society, Dec 3, 2014

The present work describes a solid-phase extraction (SPE) procedure using the molecularly imprint... more The present work describes a solid-phase extraction (SPE) procedure using the molecularly imprinted polymers (MIPs) in order to obtain a cleaner extract and high recovery from a highly complex and aqueous herbal matrix. MIPs with a similar composition of precursors were synthesized by bulk (MIPB), precipitation (MIPP) and reverse microemulsion polymerization (MIPR) methods, and the resulting MIPs were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. The MIPs were used as sorbent in SPE procedure to study their imprinting performance in the aqueous conditions. The molecularly imprinted solid-phase extraction (MISPE) procedure for selective extraction of gallic acid (GA) from the herbal extract was performed. MIPR have shown the superior performance with the 86% extraction of GA. It was observed that the morphology of the MIPs can be enhanced using various polymerization methods for improved SPE application.

Composite Interfaces, Sep 5, 2013

ABSTRACT Molecularly imprinted polymers (MIPs) are the materials mimicking the function of biolog... more ABSTRACT Molecularly imprinted polymers (MIPs) are the materials mimicking the function of biological receptors and offer many possibilities for the development of novel composite materials. A computational approach was used to study the influence of porogen on the stability of template-monomer complex for rational design of MIPs. The effect of porogenic solvent was computed through polarizable continuum model, followed by the comparison of the binding energies (G) of the template-monomer complexes in different porogens. MIPs were prepared for Gallic acid by thermal polymerization method, using acrylamide as functional monomer and ethylene glycol dimethacrylate as crosslinker in the presence of three different porogens, to validate the results of computational approach. The MIPs were characterized by the FT-IR, SEM, Brunauer-Emmett-Teller surface area characterization techniques and swelling analysis to study the influence of porogen on the morphology of MIPs. The performance of prepared MIPs was evaluated by batch binding experiments, Langmuir-Freundlich isotherm model and selectivity experiments. MIP prepared in THF showed the highest binding capacity and selectivity with an imprinting factor of 7.74. The results of quantum chemical computational analysis were in good accordance with the experimental results.

Journal of Molecular Recognition, Mar 28, 2017

Ion cum molecularly dual imprinted polymer (DMIP) was synthesized for the simultaneous removal of... more Ion cum molecularly dual imprinted polymer (DMIP) was synthesized for the simultaneous removal of salicylic acid (SA) and cadmium (Cd) by suspension polymerization method using chitosan (CTS) as functional polymer, epichlorohydrin as cross-linker, and 4-hydroxy benzoic acid (4HBA) as well as Cd as organic and inorganic templates, respectively. Use of the dummy template 4HBA during the synthesis of DMIP had the advantage of creating imprinted cavities in DMIP, which depicted good uptake for SA. Scanning electron microscopy and Fourier transform infrared spectroscopy indicated successful preparation of DMIP. Particle size analysis confirmed polydispersity, and thermal and swelling studies indicated the mechanical stability in DMIP. The rebinding capacities of the DMIP for Cd and SA were found to be 38.46 and 23.81 mgg-1 , respectively, under the optimize condition of the time, dose, and concentration. Adsorption isotherm results fitted into Langmuir adsorption isotherm model with the R 2 values of 0.994 and 0.995 for Cd and SA, respectively. The presence of intramolecular hydrogen bonding in SA, stability of the template-monomer complexes (CTS-SA and CTS-4HBA), and the involvement of the hydroxyl groups on DMIP for the uptake of SA has been supported by molecular modeling studies using Gaussian 03 software. The electron doublet of the amino groups of DMIP was involved for the uptake of Cd. Lower binding efficiency of DMIP for SA as compared to Cd may be due to the partial participation of hydroxyl group in cross-linking with epichlorohydrin during the synthesis of DMIP.

Environment, Development and Sustainability, Nov 21, 2010

This paper presents an overview of sustainability of implementation of Common Effluent Treatment ... more This paper presents an overview of sustainability of implementation of Common Effluent Treatment Plant (CETP) in Southern India. Implementation of a CETP for the treatment of combined wastewater from small-scale tannery has proved to be a technoeconomic option and offered environmentally and economically sustainable method of treatment. Various aspects such as adequacy assessment and upgradation of CETP based on the treatability studies, energy audit, cost-benefit analysis, effect of implementation of CETP on surrounding groundwater and organizational management setup were studied over a period of 4 years to analyse the sustainability of the CETP. The concept of CETP makes effective use of human, technical, and financial and natural resources and financially sustainable, i.e. being a collective responsibility, it does not fail due to financial constraints. The implementation of CETP is a true example of a step towards sustainable development and suggests that this concept can be effectively used for treatment of various industrial wastewaters emanating from small-scale clusters.

Environmental Monitoring and Assessment, Aug 9, 2016

The present study reports a precise and simple offline solid-phase extraction (SPE) coupled with ... more The present study reports a precise and simple offline solid-phase extraction (SPE) coupled with reversed-phase high-performance liquid chromatography (RP-HPLC) method for the simultaneous determination of five representative and commonly present pharmaceuticals and personal care products (PPCPs), a new class of emerging pollutants in the aquatic environment. The target list of analytes including ciprofloxacin, acetaminophen, caffeine benzophenone and irgasan were separated by a simple HPLC method. The column used was a reversed-phase C18 column, and the mobile phase was 1 % acetic acid and methanol (20:80 v/v) under isocratic conditions, at a flow rate of 1 mL min −1. The analytes were separated and detected within 15 min using the photodiode array detector (PDA). The linearity of the calibration curves were obtained with correlation coefficients 0.98-0.99.The limit of detection (LOD), limit of quantification (LOQ), precision, accuracy and ruggedness demonstrated the reproducibility, specificity and sensitivity of the developed method. Prior to the analysis, the SPE was performed using a C18 cartridge to preconcentrate the targeted analytes from the environmental water samples. The developed method was applied to evaluate and fingerprint PPCPs in sewage collected from a residential engineering college campus, polluted water bodies such as Nag river and Pili river and the influent and effluent samples from a sewage treatment plant (STP) situated at Nagpur city, in the peak summer season. This method is useful for estimation of pollutants present in microquantities in the surface water bodies and treated sewage as compared to nanolevel pollutants detected by mass spectrometry (MS) detectors.

Environmental Research, Sep 1, 2022

Adsorption Science & Technology, 2012

The present work compares the molecular recognition abilities of two molecularly imprinted polyme... more The present work compares the molecular recognition abilities of two molecularly imprinted polymers (MIPs) synthesized using two different functional monomers, viz. acrylamide (AA) and 4-vinylpyridine (4-Vp), employing gallic acid (GA) as the template using the non-covalent imprinting approach employing ethylene glycol dimethacrylate (EGDMA) as the cross-linker and 2,2-azo-bis-2-isobutyronitrile (AIBN) as an initiator in the porogen acetonitrile by thermal polymerization. The change in the electronic stabilization energies (∆E) of the template-monomer complexes formed between the template and functional monomers in the presence of the porogen were computed using Density Functional Theory (DFT) to interpret the nature of the interactions between them and to compare their stabilities. A systematic investigation of the molecular recognition abilities of the synthesized MIPs has been carried out by applying the Langmuir-Freundlich (L-F) adsorption isotherm model. The binding parameters obtained from the L-F model demonstrate that MIP AA exhibited a higher specific molecular recognition ability towards the template molecule.

Environmental Science and Pollution Research, Mar 29, 2022

The major reason behind the spread of antibiotic resistance genes (ARGs) is persistent selective ... more The major reason behind the spread of antibiotic resistance genes (ARGs) is persistent selective pressure in the environment encountered by bacteria. Genome plasticity plays a crucial role in dissemination of antibiotic resistance among bacterial pathogens. Mobile genetic elements harboring ARGs are reported to dodge bacterial immune system and mediate horizontal gene transfer (HGT) under selective pressure. Residual antibiotic pollutants develop selective pressures that force the bacteria to lose their defense mechanisms (CRISPR-cas) and acquire resistance. The present study targets the ESKAPE organisms (namely, Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter spp.) causing various nosocomial infections and emerging multidrug-resistant species. The role of CRISPR-cas systems in inhibition of HGT in prokaryotes and its loss due to presence of various stressors in the environment is also focused in the study. IncF and IncH plasmids were identified in all strains of E. faecalis and K. pneumoniae, carrying Beta-lactam and fluoroquinolone resistance genes, whereas sal3, phiCTX, and SEN34 prophages harbored aminoglycoside resistance genes (aadA, aac). Various MGEs present in selected environmental niches that aid the bacterial genome plasticity and transfer of ARGs contributing to its spread are also identified.

Elsevier eBooks, 2019

Abstract The widespread use and presence of pharmaceuticals and personal care products (PPCPs) in... more Abstract The widespread use and presence of pharmaceuticals and personal care products (PPCPs) in aquatic environment throughout the world and their potential biological activity suggest that understanding how these compounds can influence aquatic ecosystem functions is an important research direction. PPCPs are widely studied and the number of papers published in SCI journals is >1500 in 2017 itself and >7000 since 2012 ( https://scholar.google.co.in ). The present chapter discusses the classification and possible environmental sources of PPCPs. It also details the fate, pathways, persistence, and ecotoxicological profile of these compounds focusing on aquatic environment. The efficiency and limitations of the existing conventional/advanced water/wastewater treatment systems in the removal of these compounds are also overviewed to understand the aquatic environmental pathway of PPCPs. The chapter describes the steps toward directives and regulations and the key strategy adopted for the basis of concern.

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Dec 1, 2013

h i g h l i g h t s Density functional theory based computational studies for the Gallic acid bas... more h i g h l i g h t s Density functional theory based computational studies for the Gallic acid based MIP. Vibrational wavenumbers calculations based on DFT employing B3LYP/6-31+G(2d,2p) level. Optimal mole ratio of 1:4 with formation of intermolecular hydrogen bond between GA and AA.

Expert Systems With Applications, Sep 1, 2011

The selection of optimal wastewater treatment alternative involves multiple objectives and/or cri... more The selection of optimal wastewater treatment alternative involves multiple objectives and/or criteria and hierarchy process. This study integrates analytical hierarchy process (AHP) and grey relation analysis (GRA) for optimal selection of full scale tannery effluent treatment plants. For this purpose, seven tanneries and their effluent treatment facilities are studied in detail in Southern India. The objective hierarchy criterion is considered based on three factors; economic, technical, and administrative, each of which again involves hierarchy of indices. A realistic treatment alternative selection is obtained since all the data used is on actual basis. The biggest advantage of this approach is that it provides the information regarding the scope for further improvement in existing treatment options. The study indicates that the AHP and grey relation analysis are powerful tools that can be used for implementation of appropriate wastewater treatment technology.

Environmental Monitoring and Assessment, Aug 10, 2017

This paper reports the seasonal variation and environmental quality control data for five fingerp... more This paper reports the seasonal variation and environmental quality control data for five fingerprint pharmaceuticals and personal care products (PPCPs) (acetaminophen ciprofloxacin, caffeine, irgasan and benzophenone) in the influent and the effluent of the sewage treatment plant (STP) and surface water bodies (six major lakes) in and around Nagpur, one of the BA class city^in the central India over a period of 1 year. The target compounds were analysed using developed offline solid-phase extraction (SPE) coupled with reversed phase high-performance liquid chromatography (RP-HPLC-PDA) method. All the five PPCPs were found in the influent, whereas four were found in the effluent of the STP. However, in the surface water bodies, three PPCPs were detected in all the seasons. Above PPCPs were present in the concentration range of 1-174 μg L −1 in the surface water bodies, 12-373 μg L −1 in the influent and 11-233 μg L −1 in the effluent of the STP. Amongst the five PPCPs, caffeine was found to be in higher concentration as compared to others. The seasonal trends indicate higher concentrations of PPCPs in summer season and lowest in the rainy season. Additionally, physico-chemical characterisations (inorganic and organic parameters) of the collected samples were performed to access the anthropogenic pollution. Ecotoxicological risk assessment was done to appraise the degree of toxicity of the targeted compounds. Hazard quotient (HQ) values were found to be < 1 indicating no adverse effect on the targeted organism.

Food Chemistry, Mar 1, 2014

This paper reports the preparation of Gallic acid (GA) molecularly imprinted polymers (MIPs) by t... more This paper reports the preparation of Gallic acid (GA) molecularly imprinted polymers (MIPs) by the precipitation polymerization and highlights the effect of porogen on particle size and specific molecular recognition properties. MIP, M-100 prepared in the porogen, acetonitrile and MIP, M-75 prepared in a mixture of acetonitrile-toluene (75:25 v/v), resulted in the formation of microspheres with approximately 4µm particle size and surface area of 96.73 m 2 g-1 and nanoparticles (0.8 to 1000 nm) and a surface area of 345.9 m 2 g-1 , respectively. The Langmuir-Freundlich isotherm study revealed that M-75 has comparatively higher number of binding sites which are homogenous and has higher affinity for GA. The MIPs selectively recognized GA in presence of its structural analogues. Pure GA with percent recovery of 75 (±1.6) and 83.4 (±2.2) was obtained from the aqueous extract of Emblica officinalis by M-100 and M-75, respectively and hot water at 60ºC served as the eluting solvent.

Materials Science Forum, Jul 1, 2013

Carbonate is a common pollutant in water and wastewater. A study to understand its influence on t... more Carbonate is a common pollutant in water and wastewater. A study to understand its influence on the photodegradation rates is necessary especially when TiO2/UV technique is emerging as an advanced technology for pollution abatement. In the present investigation, we report surface modification of titanium dioxide using carbonate ions, characterization of carbonate modified titanium dioxide (CMT) and photocatalytic application of carbonate modified TiO2. Titanium dioxide from two different sources namely BDH, Mumbai and Degussa AG, Germany was used as photocatalyst. The CMT catalysts were characterized using potentiometry, FT-IR and XPS. Approximately, 18.9 mg CO3/g CMT(BDH) and 8.13 mg CO3/g CMT(Degussa) was found loaded as determined by potentiometry. The C 1s and O 1s binding energies observed at 289.2 and 531.3 eV, respectively were attributed to surface carbonate species. The adsorption and photodegradation of Acid Blue I dye examined using neat TiO2as well as CMT catalysts revealed that carbonate inhibits catalytic activity for color and Chemical Oxygen Demand (COD) removal. The photo degradation rate constant (k, s-1) decreases gradually with increasing concentration of carbonate. Thus, in the absence of carbonatekdyeis 5.45 × 10-4s-1(R2= 0.97) andkCODis 3.50 × 10-5s-1(R2= 0.97). At 100 mg/L CO32-,kdyeis 0.16 × 10-4s-1(R2= 0.96) andkCODis 2.66 × 10-5s-1(R2= 0.98). In addition, the carbonate spiking studies revealed the onset of inhibition soon after the addition of carbonate into reacting suspensions of TiO2. The results suggest that carbonate inhibits catalytic activity through formation of strong surface complex under suitable pH by displacing OH2+and OH groups from TiO2surface. This results not only in fewer (OH)surfacegroups available for h+trapping for oxidation into OH radicals but also in non-availability of adsorption sites for the dye molecules. A pretreatment to remove carbonate from (waste) water appears necessary prior to application of TiO2/UV technique

Materials Science Forum, Feb 1, 2011

Molecularly imprinted polymers (MIPs) have been demonstrated to be a promising class of biomimeti... more Molecularly imprinted polymers (MIPs) have been demonstrated to be a promising class of biomimetic materials that can be tailored to meet specific end use recognition requirements. Molecular imprinting is achieved by the interaction, either covalent or non-covalent between complementary groups in a template molecule and functional monomer units through polymerization. MIPs have been widely employed for divers applications such as chiral separation, chemical sensing, catalysis, drug screening, chromatographic separations and solid phase extraction. During respiration and metabolism, human body produce free radicals as by products, which can damage genetic material, lipids and proteins leading to several fatal diseases such as Cancer, Cardio-vascular disease, Alzheimer’s disease, Immune dysfunction etc. Antioxidants define a family of natural or synthetic nutrients in food, which acts as free radical scavengers. They are present in complex matrix such as herbs, fruit pulp in small concentration, either combined or in free form. Although several techniques have been developed for their detection, (e.g. HPLC, Thin layer chromatography, Capillary gas chromatography, Supercritical fluid chromatography), to achieve highly specific and sensitive analysis, high affinity, stable and specific recognition agents are needed. In this review, special attention is paid to the MIPs based analytical methods for antioxidants, focusing on solid phase extraction, chromatographic and non chromatographic separations and sensing approaches as well as on novel approaches for the discovery of new imprinted materials for antioxidants.

Journal of Environmental Chemical Engineering