Poornima G Hiremath
@sit.ac.in
Assistant professor and Chemical Engineering
Siddaganga Institute of Technology
EDUCATION
B.E., M.Tech., Ph.D. in Chemical Engineering
RESEARCH INTERESTS
Water and wastewater treatment, Mass transfer, Bioremediation, Material Science
Scopus Publications
Scholar Citations
Scholar h-index
Scholar i10-index
Scopus Publications
Poornima G. Hiremath, G.K. Prashanth, Abdul Bais Kadli, Sheril Varghese, and Vishnu V. Bhaskar
IOS Press
In the present work, zirconia nanoparticles were investigated for the adsorption of fluoride from water. The effect of the factor variables viz., the effect of initial fluoride concentration, adsorbent dosage, pH, and contact time and their interactions on adsorption of fluoride ion were investigated by response surface methodology (RSM) based on central composite design (CCD). The maximum fluoride removal was around 95% at 7 pH, initial fluoride concentration of 10 ppm, adsorbent dosage of 12.5 g/L, and contact time at 105 min. To understand the adsorption mechanism of fluoride on to the nanoparticles, adsorption isotherms and adsorption kinetics were studied. The Langmuir isotherm adsorption model and pseudo-second-order kinetics model fitted well for the fluoride removal using zirconia nanoparticles. The nanoparticles were characterised before and after for their adsorption using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and SEM analysis.
Poornima G. Hiremath, Nagaraju Ganganagappa, Udayabhanu, Sujay S. Suresh, Sushmitha Sajjan, and Rishitha K. Nanjundappa
Springer Science and Business Media LLC
Poornima G. Hiremath, Harish Phattepur, Omkar S. Baradol, and K. V. Shreyas
Informa UK Limited
Mahesh Kumar Shetty, K.V. Karthik, Jagadish H. Patil, S. Murthy Shekhar, SM Desai, Poornima G Hiremath, and R Ravishankar
Elsevier BV
Harish Phattepur and Poornima G. Hiremath
Elsevier BV
Poornima G. Hiremath, Rajashekhara S, Prakash Binnal, and Thomas Theodore
Elsevier
Suman Pawar, Thomas Theodore, and Poornima G. Hiremath
Rasayan Journal of Chemistry
The potential of hydroxyapatite particles prepared from avocado peel (APH) for the removal of Cr (VI) ions from aqueous solutions was studied. The APH was characterized using x-ray diffraction; Fourier transforms infrared spectroscopy, and scanning electron microscopy. The adsorption of Cr (VI) ions from aqueous solutions onto APH was studied. The batch adsorption experiments were performed in 250-cm 3 Erlenmeyer flasks containing 100 cm 3 solution of Cr (VI) of known concentration with a known mass of adsorbent (APH) added to the solution. The flasks were agitated at 120 rpm on a rotary shaker incubator for a known time at 30°C. The impact of different parameters such as initial Cr (VI) concentration, adsorbent dosage, contact time, and pH of the solution was studied. The hexavalent chromium removal efficiency (91.27%) increased with increase in initial Cr (VI) ions concentration (50 to 200 mg/L), and adsorbent dosage (0.1 to 0.5 g/100 mL). The adsorption isotherms and kinetics of the process were also studied. The Freundlich adsorption isotherm well explained Cr (VI) adsorption onto APH. Cr (VI) adsorption onto APH very well agreed with the pseudo-second-order kinetic model as indicated by the R 2 value (0.99). APH is an eco-friendly and low-cost adsorbent. APH is very effective for the removal of hexavalent chromium from aqueous solutions.
Poornima G. Hiremath and Thomas Theodore
Informa UK Limited
Abstract The present investigation deals with the biosorption of fluoride from aqueous solutions using calcium-doped Chlorella vulgaris, Chlorella protothecoides, and Nannochloropsis oculata. Effects of the factor variables (initial fluoride concentration, pH, biosorbent dose, and contact time) and their interactions on sorption of fluoride ion were investigated by response surface methodology based on central composite design. Maximum fluoride biosorption of 78.7% was obtained from calcium-doped C. vulgaris biomass. The fluoride biosorption followed pseudo-second-order kinetics. The fluoride sorption capacity was found to be 7.554, 7.549, and 7.827 mg/g for C. vulgaris, C. protothecoides, and N. oculata species, respectively. The biosorbent was characterised using scanning electron microscope with energy-dispersive spectroscopy and Fourier transform infrared. This study provides the efficiency of modified algal biomass for biosorption of fluoride. The positive results encourage extending the usage of the naturally abundant or waste algal biomass to remove other toxic heavy metals from the environment.
Poornima G Hiremath and Thomas Theodore
Hindawi Limited
In the present work, an economical, more selective and a bio-compatible fluoride removal technique has been developed by using zirconium impregnated Chlorella protothecoides and Nannochloropsis oculata, which represents a combination of biological and physiochemical methods. The optimization of the effect of various factors such as pH, initial fluoride concentration, biosorbent dose and contact time was carried using a central composite design of response surface methodology. A maximum removal of fluoride ions of 92.2% was observed using zirconium-doped C. protothecoides. The adsorption isotherms and kinetics of the adsorption process were studied. The Langmuir isotherm model well expressed fluoride biosorption onto zirconium-doped N. oculata and the Freundlich isotherm model fitted well the data of zirconium-doped C. protothecoides. The correlation coefficients indicate that the fluoride biosorption onto zirconium-doped N. oculata, and C. protothecoides biosorbents correlated well with the pseudo-second-order kinetic model. The existence of co-anions decreased fluoride removal from aqueous solution. The biosorbent was regenerated using NaOH, distilled water and HCl and used for four cycles.
Poornima G. Hiremath and Thomas Theodore
Periodica Polytechnica Budapest University of Technology and Economics
The potential of immobilized Chlorella vulgaris to remove fluoride from synthetic and real ground water samples in a fixed bed was investigated. The effect of important kinetic parameters including column bed height, feed flow rate and influent fluoride concentration of solution on fluoride removal was studied. Thomas, Yoon-Nelson, and BDST models were used to analyze the experimental data and understand the influence on biosorption performance. The models’ predictions were in good agreement with the experimental data for all the process parameters studied, indicating that the models were suitable for fixed-bed column design. Fluoride adsorption was reversible. Desorption of fluoride ions was accomplished by pumping 0.1 N HCl solution. The reusability of adsorbent was studied by subjecting column to repeated cycles of fluoride adsorption and desorption. The suitability of immobilized C. vulgaris adsorbent for fluoride removal from ground water samples of Pavagada taluk, Tumakuru district was studied in the packed column.
Prakash Binnal and Poornima G. Hiremath
Springer Science and Business Media LLC