Srivastava / Goyal Novel Biomaterials

Decontamination of Toxic Metals from Wastewater
1. Auflage 2010
ISBN: 978-3-642-11329-1
Verlag: Springer
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, 190 Seiten

Reihe: Environmental Science and Engineering

Current research revolves around trends to bring technology into harmony with the natural environment and in order to protect the ecosystem. Bioremediation involves processes which reduce the overall treatment costs by using agricultural residues. Regeneration of the biosorbent further increases the cost effectiveness of the process, thus warranting its future success in solving water quality problems. Special emphasis is paid to chemical modifications resulting in tailored novel biomaterials which improve its sorption efficiency and environmental stability. In this way it can be used commercially as a simple, fast, economical, ecofriendly green technology, for the removal of toxic metals from waste water particularly in rural and remote areas of the country.

Autoren/Hrsg.

Srivastava, Shalini

Goyal, Pritee

Inhaltsverzeichnis

1;Preface;6
2;Contents;10
3;About the Authors;14
4;Heavy Metals: Environmental Threat;15
4.1; Cadmium;16
4.2; Nickel;17
4.3; Lead;19
4.4; Chromium;23
5;Detoxification of Metals Biochelation;25
5.1; Chemistry of Chelation;25
5.2; Characteristics of a Chelating Agent;26
5.3; Chelating Agents and Their Properties;27
5.4; Metal Detoxification by Chelating Agents;28
5.4.1; Arsenic;28
5.4.2; Cadmium;29
5.4.3; Lead;30
5.4.4; Mercury;31
5.5; Side Effects of Chelation Therapy and Possible Solutions;32
6;Metal Decontamination: Techniques Used So Far;35
6.1; Distillation;35
6.2; Evaporation;35
6.3; Chemical Precipitation;35
6.4; Flocculation and Coagulation;36
6.5; Electrocoagulation;36
6.6; Ion Exchange;38
6.7; Membrane Process;39
6.8; Ultrafiltration;39
6.9; Reverse Osmosis;40
6.10; Electrodialysis;41
6.11; Nanofiltration;42
7;Existing Metal Removal Technologies: Demerits;44
8;Hyperaccumulation: A Phytoremedial Approach;45
8.1; Which Plant?;46
8.2; Hyperaccumulation and Hypertolerance;49
8.3; Mechanisms of Hyperaccumulation;50
9;Biosorption: A Promising Green Approach;55
10;Biosorption: Mechanistic Aspects;59
10.1; Biosorption Mechanism;59
10.2; Chemisorption;59
10.3; Physiosorption;62
11;Biosorbents Used So Far;63
12;Biosorption: Application Strategies;65
12.1; Assessment of the Competing Technologies;66
12.2; Assessment of the Market Size;66
12.3; Assessment of Costs of New Biosorbent;66
13;Designing of Experiments;68
13.1; Metal Analysis Using Various Instruments;68
13.2; Instrumentation;69
13.2.1; Atomic Absorption Spectrometer;70
13.2.1.1; Principle;71
13.2.1.2; Sensitivity and Detection Limit;71
13.2.2; Neutron Activation Analyzer;72
13.2.2.1; Principle of Neutron Activation Analysis;72
13.2.2.2; NAA Detectors;73
13.2.2.3; Detection Limit;73
13.2.2.4; Accuracy and Precision;73
13.2.2.5; Sensitivity;74
13.2.2.6; Photoelectric Effect;74
13.2.2.7; Compton Scattering;75
13.2.2.8; Pair Production;75
13.2.2.9; Simple Counting System;76
13.2.2.10; General Principle of Detection;76
13.2.3; NaI (TI) Scintillator Detector;76
13.2.3.1; Multi-channel Analyzer;77
13.2.3.2; Interference in Gamma Counting;77
13.2.3.3; Background Radiations;77
13.2.3.4; Sample Geometry;78
13.2.3.5; Dead Time;78
13.2.3.6; Energy and Efficiency Calibration;78
13.2.3.7; Calculation for Metal Uptake;79
13.2.3.8; Sorption Isotherm;79
13.2.4; Considerations for Desorption Experiment;79
13.2.5; Statistical Analysis;80
14;Interpretations;81
14.1; Single Metal Sorption;81
14.1.1; Effect of Particle Size on Metal Sorption;81
14.1.2; Effect of Contact Time on Metal Sorption;81
14.1.3; Effect of Biomaterial Dosage on Metal Sorption;92
14.1.4; Effect of Concentration on Metal Sorption;93
14.2; Mechanistic Aspects of Sorption;94
15;Sorption Isotherms and Kinetics;97
15.1; Freundlich Isotherm;97
15.2; Langmuir Isotherm;97
16;Reusability of Biomaterial: A Cost-Effective Approach;102
17;Characterization of MetalBiomaterial Interaction;106
17.1; Biosorption BET Studies;106
17.2; Scanning Electron Microscopic Analysis (SEM);106
17.3; FTIR Studies;109
18;Protein as Possible Bioactive Principle;112
18.1; Active Sites for Sorption;112
18.1.1; Esterification;112
18.1.2; Propylamination;113
18.2; Isolation and Characterization of Protein;114
18.3; Quantification of Protein;115
18.4; Molecular Weight Determination (Gel Electrophoresis);116
18.5; Characterization of Protein;117
19;Novel Biomaterials Commercialization Approach;119
19.1; Synthetic Modifications onto Biomaterial to Increase Its Sorption Efficiency for Cationic Metals;120
19.1.1; Strengthening of Bioactive Functional Group [COO -- ];120
19.1.2; Reaction with Anhydrides;120
19.1.3; Reactions with Acids;122
19.1.4; Oxalic Acid Modified SMOS;122
19.1.5; Malonic Acid Modified SMOS;122
19.1.6; Succinic Acid Modified SMOS;122
19.1.7; Citric Acid Modified SMOS;123
19.1.8; Tartaric Acid Modified SMOS;123
19.1.9; Evidence in Support of Chemical Modifications Occurring on Biomaterials Leading to Enhanced Sorption;123
19.1.10; Evaluation of Enhanced Sorption Efficiency of Modified Biomaterial;123
19.1.11; Graft Co-polymerization;126
19.1.12; Graft Co-polymerization with Acrylic Acid;126
19.1.13; Graft Co-polymerization with Maleic Acid;127
19.1.14; Graft Co-polymerization with Itaconic Acid;128
19.1.15; Evidence in Support of Improved Environmental Stability of the Biomaterial;128
19.1.16; Synthetic Modifications onto Biomaterial to Increase Its Sorption Efficiency for Anionic Metals;130
19.2; Impregnation of Positively Charged Layer;130
20;Suggested Reading;134
21;Index;145

Leseproben

"Biosorption: A Promising Green Approach (p. 43-44)

Unfortunately, the science particularly chemistry, despite numerous contributions to the well-being and progress of humanity, has been blamed for the present ills of the world. In fact, it is not chemistry or science or technology but our past mistakes of increasing only the production without considering the simultaneous generation of large amounts of side products or waste which have underlined us as the culprit. Basically unscientific and careless rapid urbanization, industrialization, and agriculturalization are major threats to the environment.

It is not the need of poor but the greed of rich nation, which has been the main cause of environmental degradation of the world. Chemists, since 1990, have started addressing complicated environmental issues in a safe and an economically profitable manner under various names like Clean Chemistry, Environmentally Benign Chemistry, Sustainable Chemistry, Come Back to Nature, Gray to Green Chemistry, Green Technologies, Eco-friendly Techniques, Green Processes, and more popularly Green Chemistry. Green Chemistry is a special contribution of chemists to the conditions for sustainable development, incorporating an environmentally benign design approach to all aspects of chemical industry.

The word Green Chemistry was coined jointly by Prof. Paul T. Anastas and Prof. John C. Warner, which means “The invention, design and application of chemical products and processes to reduce or to eliminate the use and generation of hazardous substances.” To combine technology with environmental safety is one of the key challenges of the new millennium. There is a global trend of bringing technology into harmony with the natural environment, thus aiming to achieve the goals of protection of ecosystem from the potentially deleterious effects of human activity and finally improving its quality.

The magic plants are around and waiting to be discovered and commercialized. They are now recognized and accepted as storehouses of infinite and limitless benefits to human beings. These natural systems are often referred to as Green Technologies as they involve naturally occurring plant materials. Biosorption is one such important phenomenon, which is based on one of the 12 principles of Green Chemistry, i.e., “Use of renewable resources.”"