Veeramuthu Ashokkumar

Mass culture of Botryococcus braunii Kutz. under open raceway pond for biofuel production.

Three different strains of colonial green alga Botryococcus bruanii Kutz. AP103, AP104 and AP105 were isolated from the freshwater lake Kolleru, Andhra Pradesh, India. The morphological features of these three isolates were studied under laboratory conditions. Molecular identification of the strains was carried out using 18S rRNA analysis and their systematic position was confirmed to species level as B. braunii. Among these isolates, B. braunii AP103 recorded highest biomass concentration of 1.7±0.12 g L(-1), 17% lipids, 17% proteins, 32% carbohydrates and 13% hydrocarbons under laboratory condition. Under open raceway pond AP103 produced a biomass concentration of 1.8±0.13 g L(-1), 19% lipids, 33% carbohydrates, 18% proteins and 11% hydrocarbons. The hydrocarbons profile showed the presence of heptadecane (34%) and hexadecane (12.5%). Oleic (25.7%), linolenic (34.26%) and palmitic (9.42%) acids were the major fatty acids present in the lipids extracted from AP103.

A study on large scale cultivation of Microcystis aeruginosa under open raceway pond at semi-continuous mode for biodiesel production

The study explores on upstream and downstream process in Microcystis aeruginosa for biodiesel production. The alga was isolated from temple tank, acclimatized and successfully mass cultivated in open raceway pond at semi-continuous mode. A two step combined process was designed and harvested 99.3% of biomass, the daily dry biomass productivity was recorded up to 28gm(-2)day(-1). The lipid extraction was optimized and achieved 21.3%; physicochemical properties were characterized and found 11.7% of FFA, iodine value 72% and 99.2% of ester content. The lipid was transesterified by a two step simultaneous process and produced 90.1% of biodiesel; the calorific value of the biodiesel was 38.8MJ/kg. Further, the physicochemical properties of biodiesel was characterized and found to be within the limits of American ASTM D6751. Based on the areal and volumetric biomass productivity estimation, M. aeruginosa can yield 84.1 tons of dry biomass ha(-1)year(-1).

Optimization of Biodiesel Synthesis from Calophyllum inophyllum

In this study, nano-size calcium-based heterogeneous catalyst derived from lime sludge was used for biodiesel production. Its catalytic activity in transesterification of Calophyllum inophyllum (C. inophyllum) oil and the physicochemical properties of synthesized biodiesel were systematically investigated. Due to high free fatty acids two-step acid esterification and alkali transesterification were performed. Transesterification reaction follows pseudo-first-order kinetics and their rate constants were determined. Activation energy and frequency factor were found to be 20.69 kJ mol–1 and 0.219 s–1, respectively. The fuel properties of the derived biodiesel was analyzed according to ASTM methods.

Removal of Acid Blue25 from aqueous solutions using Bengal gram fruit shell (BGFS) biomass

ABSTRACT The feasibility for the removal of Acid Blue25 (AB25) by Bengal gram fruit shell (BGFS), an agricultural by-product, has been investigated as an alternative for high-cost adsorbents. The impact of various experimental parameters such as dose, different dye concentration, solution pH, and temperature on the removal of Acid Blue25 (AB25) has been studied under the batch mode of operation. pH is a significant impact on the sorption of AB25 onto BGFS. The maximum removal of AB25 was achieved at a pH of 2 (83.84%). The optimum dose of biosorbent was selected as 200 mg for the removal of AB25 onto BGFS. Kinetic studies reveal that equilibrium reached within 180 minutes. Biosorption kinetics has been described by Lagergren equation and biosorption isotherms by classical Langmuir and Freundlich models. Equilibrium data were found to fit well with the Langmuir and Freundlich models, and the maximum monolayer biosorption capacity was 29.41 mg g−1 of AB25 onto BGFS. The kinetic studies indicated that the pseudo-second-order (PSO) model fitted the experimental data well. In addition, thermodynamic parameters have been calculated. The biosorption process was spontaneous and exothermic in nature with negative values of ΔG° (−1.6031 to −0.1089 kJ mol−1) and ΔH° (−16.7920 kJ mol−1). The negative ΔG° indicates the feasibility of physical biosorption process. The results indicate that BGFS could be used as an eco-friendly and cost-effective biosorbent for the removal of AB25 from aqueous solution.

Modified phyto-waste Terminalia catappa fruit shells

This study investigated the preparation of a reusable adsorbent from the phyto-waste Terminalia catappa fruit shells by acid-thermal modification and utilization for the removal of diclofenac from aqueous systems. The structural characteristic features of the modified T. catappa fruit shells (MTCFS) were analysed using Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy and Brunauer–Emmett–Teller analysis. Batch experiments proved that temperature and pH mainly influenced the adsorption process. The Langmuir and Freundlich isotherms were obeyed for the diclofenac adsorption. The Temkin isotherm model revealed that increasing temperature affected the adsorption of diclofenac. The Dubinin–Radushkevich isotherm indicated that the present adsorption system was achieved through physical interactions. A pseudo-second-order kinetic model was well fitted for the diclofenac adsorption. Intraparticle diffusion results indicated increases in the rate of adsorption and in the boundary layer thickness. The thermodynamic results revealed that increasing the temperature inversely affected the diclofenac adsorption. Recycling experiments confirmed that the MTCFS were found to be quite stable and retained their adsorption efficiency for up to eight cycles of diclofenac removal.