Baskar Gurunathan

Biodiesel production from waste cooking oil using copper doped zinc oxide nanocomposite as heterogeneous catalyst.

A novel CZO nanocomposite was synthesized and used as heterogeneous catalyst for transesterification of waste cooking oil into biodiesel using methanol as acyl acceptor. The synthesized CZO nanocomposite was characterized in FESEM with an average size of 80 nm as nanorods. The XRD patterns indicated the substitution of ZnO in the hexagonal lattice of Cu nanoparticles. The 12% (w/w) nanocatalyst concentration, 1:8 (v:v) O:M ratio, 55 °C temperature and 50 min of reaction time were found as optimum for maximum biodiesel yield of 97.71% (w/w). Hence, the use of CZO nanocomposite can be used as heterogeneous catalyst for biodiesel production from waste cooking oil.

Process optimization and kinetics of biodiesel production from neem oil using copper doped zinc oxide heterogeneous nanocatalyst

Heterogeneous nanocatalyst has become the choice of researchers for better transesterification of vegetable oils to biodiesel. In the present study, transesterification reaction was optimized and kinetics was studied for biodiesel production from neem oil using CZO nanocatalyst. The highly porous and non-uniform surface of the CZO nanocatalyst was confirmed by AFM analysis, which leads to the aggregation of CZO nanoparticles in the form of multi layered nanostructures. The 97.18% biodiesel yield was obtained in 60min reaction time at 55°C using 10% (w/w) CZO nanocatalyst and 1:10 (v:v) oil:methanol ratio. Biodiesel yield of 73.95% was obtained using recycled nanocatalyst in sixth cycle. The obtained biodiesel was confirmed using GC-MS and (1)H NMR analysis. Reaction kinetic models were tested on biodiesel production, first order kinetic model was found fit with experimental data (R(2)=0.9452). The activation energy of 233.88kJ/mol was required for transesterification of neem oil into biodiesel using CZO nanocatalyst.

Biological synthesis and characterization of intracellular gold nanoparticles using biomass of Aspergillus fumigatus

Nanotechnology is emerging as one of the most important and revolutionizing area in research field. Nanoparticles are produced by various methods like physical, chemical, mechanical and biological. Biological methods of reduction of metal ions using plants or microorganisms are often preferred because they are clean, non-toxic, safe, biocompatible and environmentally acceptable. In the present study, Aspergillus fumigatus was used for the intracellular synthesis of gold nanoparticles. Stable nanoparticles were produced when an aqueous solution of chloroauric acid (HAuCl4) was reduced by A. fumigatus biomass as the reducing agent. Production of nanoparticles was confirmed by the colour change from yellow to pinkish violet after ∼ 72 h of reaction. The produced nanoparticles were then characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction spectroscopy (XRD). SEM images of sample revealed that the nanoparticles were spherical, irregularly shaped with indefinite morphology. Biosynthesized gold nanoparticles were in the range of 85·1–210 nm in size. The presence of gold nanoparticle was confirmed by EDS analysis. Crystalline nature and face-centred cubic structure of synthesized gold nanoparticle was confirmed by XRD pattern.

Carbon nanoparticle from a natural source fabricated for folate receptor targeting, imaging and drug delivery application in A549 lung cancer cells

There is an emerging need for the development of new anticancer nanocomposite which exhibits imaging properties and targeted drug delivery. In the present study, a nanobiocomposite was prepared, in this direction, which contains carbon nanoparticles (CNP), methotrexate (Mtx) and asparaginase (Asp) coupled with fluorescein isothiocyanate (FITC). The prepared nanobiocomposite kills only the cancer cells due to the presence of Mtx which is a folic acid analogue and targets the cancer cells due to the over expression of folate receptors on their surface and apoptosis occurs due to the anticancer activity of enzyme asparaginase. The results obtained from the present study confirmed the sustained release of Mtx and Asp from the nanobiocomposite. The nanobiocomposite was found to be haemocompatible, biocompatible and showed more than 90% apoptosis. The drug pathway was clearly monitored due to the presence of FITC in the nanobiocomposite. This study proves the effectiveness of the fabricated nanoconjugate, as it helps in imaging, targeting and destructing the cancerous cells. The prepared nanoconjugate may be effectively applied in in vivo experiments before applying on to humans.

Production of L-asparaginase from Natural Substrates by Aspergillus terreus MTCC 1782: Optimization of Carbon Source and Operating Conditions

In the present work, the effect of different carbon sources, namely glucose, sucrose, maltose, fructose and lactose, was studied for extracellular L-asparaginase production by Aspergillus terreus MTCC 1782 in submerged fermentation. The best carbon source and operating conditions such as initial pH, inoculum size, temperature and agitation rate were optimized. Glucose was found to be the best carbon source for L-asparaginase production using modified Czapek-Dox media containing L-proline as substrate. Sucrose was found to be the best carbon source for L-asparaginase production using modified Czapek-Dox media containing groundnut oil cake flour as substrate. Glucose was found to be the best carbon source for maximum L-asparaginase production using modified Czapek-Dox media containing soya bean meal flour as substrate. The soya bean meal flour was found to be the best natural substrate for maximum L-asparaginase activity of 35.3 IU/mL using 0.6% glucose as carbon source at the optimal culture conditions of initial pH 6, inoculum size 2%, temperature 35°C and agitation rate 160 rpm.

Bioremediation: Applications for Environmental Protection and Management

Man’s environment consists of natural resources like air, land, water, plants, and animals. With the progress of industrialization and civilization, man has interacted with his surroundings and disturbed the nature. It leads to environmental pollution, which cannot be eradicated by nature’s self-acting process, i.e., various biogeochemical cycles. Environmental problems stem from two main categories of human activities: (a) resources utilization at unsustainable levels and contamination of the environment through pollution and (b) discharge of wastes at levels beyond the earth’s and environment’s capacity to absorb them or render them harmless which results in ecological damage and degradation of the environment. Environmental damage around includes pollution of water and air and consequent health problems, biodiversity loss, deterioration of buildings and monuments, soil fertility loss, desertification, ozone depletion, and many more. Environmental protection and management has become one of the foremost concerns of the world community. International concern for environmental protection and management has gained momentum with Stockholm Declaration in 1972. It is considered as Magna Carta of environmental protection and sustainable development. Then a series of global efforts have been undertaken internationally for protection of the environS. J. Varjani (✉) Gujarat Pollution Control Board, Paryavaran Bhavan, Gandhinagar, India e-mail: drsvs18@gmail.com A. K. Agarwal Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur, India e-mail: akag@iitk.ac.in E. Gnansounou Bioenergy and Energy Planning Research Group (BPE), Swiss Federal Institute of Technology Lausanne (EPFL), Lausanne, Switzerland e-mail: edgard.gnansounou@epfl.ch B. Gurunathan Department of Biotechnology, St. Joseph’s College of Engineering, Chennai, Tamil Nadu, India e-mail: baskarg@stjosephs.ac.in

Bioremediation of Industrial and Municipal Wastewater Using Microalgae

The present scenario of increased population and industrial development leads to deterioration of freshwater and decreases the quality of water all over the world. This causes freshwater shortage in most of the area. Moreover, organic and inorganic substances released from various sources into the existing natural water bodies or environment lead to pollution. The primary and secondary treatment of wastewater had been introduced in many numbers of places to extinguish the easily settled material and to oxidize the organic matter in wastewater. But these methods were not found to be efficient because the effluent from secondary treatment is loaded with increased amount of inorganic nitrogen and phosphorus, and so, it leads to eutrophication and much more long-standing problems because of discharged heavy metals and refractory organics. On the other side, wastewater contains numerous ingredients, and interestingly, some of the compounds in the wastewater, like nitrogen and phosphorus, are identified as beneficial ingredients for microalgae cultures. Therefore, algal bioremediation can be considered as a feasible alternate technology for treating the wastewater in a cost-effective and assertable way compared to conventional water treatment process. These microalgal cultures are autotrophs, and they play a notable role in remediation of wastewater by their photosynthetic ability. A win–win situation of using microalgae in the bioremediation of industrial or municipal wastewater provides tertiary biotreatment of wastewater coupled with the production of potentially valuable biomass as bioresource for biofuel or high-value by-products. There is a mutual advantage in this method in which using wastewater for microalgal culture will minimize the use of freshwater, reduce the cost of nutrient addition, and also removal of nitrogen and phosphorous, and reduce CO2 emission. This chapter covered the overview of the role of microalgae in treatment of industrial as well as municipal wastewater.

Introduction to Environmental Protection and Management

Man’s environment consists of natural resources like air, land, water, plants, and animals. With the progress of industrialization and civilization, man has interacted with his surroundings and disturbed the nature. It leads to environmental pollution, which cannot be eradicated by nature’s self-acting process, i.e., various biogeochemical cycles. Environmental problems stem from two main categories of human activities: (a) resources utilization at unsustainable levels and contamination of the environment through pollution and (b) discharge of wastes at levels beyond the earth’s and environment’s capacity to absorb them or render them harmless which results in ecological damage and degradation of the environment. Environmental damage around includes pollution of water and air and consequent health problems, biodiversity loss, deterioration of buildings and monuments, soil fertility loss, desertification, ozone depletion, and many more. Environmental protection and management has become one of the foremost concerns of the world community. International concern for environmental protection and management has gained momentum with Stockholm Declaration in 1972. It is considered as Magna Carta of environmental protection and sustainable development. Then a series of global efforts have been undertaken internationally for protection of the environment. Hence, environmental protection has become not only local, regional, or national importance but also a global concern. Over the past several decades, growing public awareness regarding threats to the environment, informed by warnings from scientists, has led to demands that law protects the natural surroundings on which human well-being depends. Under growing pressure from national and international public opinion, governments began to demonstrate concern over the general state of the environment introduced legislation to combat pollution of inland waters, ocean, and air.

Integration of Lignin Removal from Black Liquor and Biotransformation Process

Industrial discharge has tremendously increased inorganic pollutants in water bodies all over the world. Paper and pulp mill effluent is included in one of the most pollution-generating discharges containing complex chemical compounds such as lignin. For clean and healthy water resources, the recovery of lignin from wastewater from the paper and pulp industry is of high importance. On the other hand, these pollutants can be carcinogenic, due to the chlorine lignin and chlorine phenols that are formed along the process. The main focus of this study on precipitation of lignin from the black liquor (influent) is one stage followed by dewatering/washing to improve purity of lignin. Lignin valorization is an essential process for an advanced, sustainable, and economical biomass-based industry. However, converting lignin into value-added products remains a challenge due to its heterogeneity and irregular structure. Complex nature of lignin depolymerized by aromatic-catabolizing organisms to create “biological funnels” that receive heterogeneous aromatic substrates and convert them to a few products. Microbes such as bacteria and fungi are involved in the lignin degradation. Degradation of lignin through white-rot fungi may be helpful for the biotechnical applications like biopulping, biobleaching and pulp mill effluents treatment, and soil bioremediation. White-rot fungi specifically P. chrysosporium, also known as model fungus, and Coriolus versicolor are potential degradation against recalcitrant chromophoric material in bleach plant effluents. The abundance and renewability of lignin potentially converted to valuable bioproduct may eventually replace existing technology on manufacturing industries.

Bioremediation of Volatile Organic Compounds in Biofilters

In India, 12 lakhs deaths per annum take place due to air pollution according to a report by Greenpeace organization. Volatile organic compounds are major air pollutants which are released into the environment through mobile sources, stationary sources, area sources, and natural sources. Stationary sources such as petrochemical and pharmaceutical industries release VOCs like toluene which is known to cause several health hazards including lung cancer. In addition to it, VOCs pollute air, soil, and water which are a growing environmental concern. Based on the concentration level of the VOCs, several removal techniques have been employed to combat VOCs. Non-biological methods such as ozonation, absorption, adsorption, incineration, catalytic oxidation, condensation, membrane separation are being employed. Several biological methods ranging from biotrickling filters to biofilters have been demonstrated, and they are found to be economical. The biofilters are simple to construct, easy to operate, and cost effective. Major advantage of this method is the pollutant is converted into biodegradable waste which can decompose within a moderate time frame, thus producing no secondary pollutants. In this chapter, biofilters, microorganisms, biofilter preparation and reaction mechanism are discussed. More emphasis was given on operation, processes, conditions, and stability of biofilters. The recent advancements in biofilters including application of foam for enhanced separation and the limitations of the biofiltration methods are also discussed. Future scope and summary of the chapter are given at the end of the chapter to provide an insight into biofilters research.