zeolites and their applications

zeolites and their applications

1. Materials Material  is a broad term for a chemical substance or mixture of substances that constitute Matter. There are four classes of materials studied:- Metals (ii) Polymers (iii) Ceramics (iv) Composites All metals are good conductors of heat and electricity. Polymers are made from long chain molecules which may have cross linking bonds affecting flexibility/stiffness.

2. Ceramics is a class of material, which includes plates ,cups, bricks, earthenware pots, engineering ceramics and refractory (furnace) materials. Ceramics are made by heating together materials such as silica, chalk and clays. Other chemicals may be included to act as flux and to change colour etc. Composites are mixtures of materials which give improved properties. One of the materials is the matrix or binding chemical and the other is the reinforce. A good example is GRP - glass reinforced polyester(plastic) resin. where the glass fibres increase the strength of the polyester resin.

3. 1. Metals Metals A  metal  is a material (an element, compound, or alloy) that is typically hard when in solid state, opaque, shiny, and has good electrical and thermal conductivity. Metals are generally malleable that is, they can be hammered or pressed permanently out of shape without breaking or cracking as well as fusible (able to be fused or melted) and ductile (able to be drawn out into a thin wire).  Some Examples of Metals: Ferrous metals and alloys (iron, carbon steel, alloy steel, stainless steel, tool and die steel) Nonferrous metals and alloys (aluminium, copper, magnesium, nickel, titanium, precious metals, refractory metals, super alloys).

4. 2.Polymers Polymers, both natural and synthetic, are developed via polymerization of many small molecules, known as monomers. Their consequently large molecular mass relative to small molecule compounds produces unique physical properties, including toughness,  visco -elasticity, and a tendency to form glasses and semi-crystalline  structures rather than crystals .

5. 3.Ceramics Ceramics A  ceramic  is an inorganic compound, non-metallic, solid material comprising metal, non metal or metalloid atoms primarily held in ionic and covalent bonds. Crystalline ceramics Crystalline ceramic materials are not amenable to a great range of processing. Noncrystalline ceramics Noncrystalline ceramics, being glass, tend to be formed from melts. 

6. 4.Composites A  composite material  (also called a composition material or shortened to composite, which is the common name) is a material made from two or more constituent materials with significantly different physical or chemical properties that, when combined, produce a material with characteristics different from the individual components. Typical Engineered Composite Materials include: Reinforced concrete and masonry Composite wood such as plywood Reinforced plastics, such as fibre-reinforced polymer or fibreglass Ceramic matrix composites (composite ceramic and metal matrices) Metal matrix composites and other Advanced composite materials.

7. Smart Materials Smart materials  are designed materials that have one or more properties that can be significantly changed in a controlled fashion by external stimuli, such as stress, temperature, moisture, pH, electric or magnetic fields, light, or chemical compounds. Terms used to describe smart materials include  shape memory material  (SMM) and  shape memory technology  (SMT)

8. Type of Smart Materials Photovoltaic Smart Materials

9. Classification of Materials On the Basis of Dimension

10. On the Basis of Structure Crystalline material is a material comprised of one or many crystals. In each crystal, atoms or ions show a long-range periodic arrangement. Single crystal is a crystalline material that is made of only one crystal (there are no grain boundaries). Polycrystalline material is a material comprised of many crystal (as opposed to a single-crystal material that has only one crystal). Grains are the crystal in a polycrystalline materials.

11. Nanostructured Materials Nanostructured Materials  are  materials  with a microstructure, the characteristic length scale of which is on the order of a few (typically 1–10) nanometers. 0D: quantum dots 1D: Nanowires 2D: superlattices and heterostructures Nano -Photonics Magnetic nanostructures Nanofluidic devices and surfaces 0D Electronic Structures: Quantum Dots

12. 1-D Electronic Structures: Carbon Nanotubes The folding of the sheet controls the electronic properties of the nanotubes. Carbon nanotubes  ( CNTs ) are allotropes of carbon with a cylindrical nanostructure. These cylindrical carbon molecules have unusual properties, which are valuable for nanotechnology ,   electronics, optics and other fields of materials science and technology.

13. Nano Materials

14. Discoverer - Swedish mineralogist A.F. Crönstedt Upon rapidly heating, the mineral Stilbite produces large amounts of steam from adsorbed water Zeolite ( zeo – boiling; lithos stone) Zeolites are crystalline microporous alumino -silicates, constituted by three dimensional arrangement of TO 4 tetrahedra , linked by oxygen atoms, forming different construction units and large frameworks, where identical blocks constitute unit cells. General Formula: M n+ X /n (AlO 2 - ) x (SiO 2 ) y where, n: M cation charge x + y: number of tetrahedra per unit cell y/x: atomic Si/Al ratio A.F. Crönstedt , Akad . Handl . Stockholm,18 (1756) 120. Introduction of Zeolites

15. Zeolites have pores with nanosized dimensions ( 0.3 – 0.8 nm) € Shape Selectivity a s crystalline materials, zeolites present a narrow range of pore sizes € gives better selectivity than non-crystalline materials Ion-exchange properties Acidity Transition metals Zeolite framework is composed of SiO 4 and AlO 4 tetrahedral units (Al, Si €T- atoms), sharing oxygen between every two consecutive - units Catalytic Active sites Porous and Active Site

16. Zeolite Framework How zeolites are Built Cations (Na + , NH 4 , H + , transition metals) located inside the channels or cavities of zeolites , to balance negative charges in the framework:

17. Zeolites are most useful and versatile heterogenous catalyst due to its high internal surface area, strong acid sites, selective sorption and molecular sieving properties. High internal surface area and acidity give rise to high activity, while selective sorption and molecular sieving result in high reaction selectivity. Shape and Selectivity with Zeolite

18. Types of Zeolites Zeolites are natural minerals that are mined in many parts of the world; most zeolites used commercially are produced synthetically. When developing applications for zeolites, it is important to remember that not all of these minerals are the same. There are nearly 50 different types of zeolites ( clinoptilolite , chabazite , phillipsite , mordenite , etc.) The basic differences between natural and synthetic zeolites are: Synthetics are manufactured from energy consuming chemicals and naturals are processed from natural ore bodies. Synthetic zeolites have a silica to alumina ratio of 1 to 1 and clinoptotilite ( clino ) zeolites have a 5 to 1 ratio. Clino natural zeolites do not break down in a mildly acid environment, resistant resistant silica to hold it’s structure together. The clino natural zeolite is broadly accepted for use in the agriculutral industry as a soil amendment and as a feed additive.

19. Methods for the Synthesis of Zeolites There are two main method for the synthesis of Zeollites : Hydrothermal method Microwave Method Sol-gel method Hydrothermal Method: Schematic diagram of autoclave

20. Hydrothermal Method An aluminate solution and a silicate solution are mixed together in an alkaline medium to form a milky gel or in some instances, clear solutions. Various cations or anions can be added to the synthesis mixture. The structure-directing agent is also added as a template in the mixture . Synthesis proceeds at elevated temperatures (60-200 °C) where crystals are formed through the nucleation step.

21. Microwave Method Microwave heating has the advantage of short reaction time, producing small particles with narrow size distribution and high purity. Moreover, microwave heating has found a number of application in synthetic chemistry.

22. A regular, non viscous synthesis mixture of zeolite is placed in the Teflon Autoclave. The autoclave is closed with thermocouple connected. An initial heating step up to 1000 W is applied. All samples were washed by five repetitions of centrifugation with relative centrifugal force of 48,500 g for 2 h, then decanting, and redispersion in ethanol and water with ultrasonication before analyses preparations were performed.

23. Sol-Gel Process Sol- Gel Method

24. Classification of Zeolites Classification on the bases on the pores structure: Microporous Zeolites Mesoporous Zeolites Classification on the bases of structural building unit: Primary Building Unit (PBU) Secondary Building Unit (SBU) Sodalite Cage Building Units Classification on the bases of ring structure: Small-pore zeolites , with 8-membered oxygen rings and a “free” diameter of 3 - 4.5 Å Medium-pore zeolites , with 10-member oxygen ring and a “free” diameter of 4.5 - 6 Å Large-pore zeolites , with 12-member oxygen rings and a “free” diameter of 6 - 8 Å

25. Classification of Zeolites Classification on the bases on Si/Al ratio Classification on the bases on crystal structure Geometry (Octahedral, Tetrahedral etc) S. No Name Si/Al ratio Examples 1. Low silica zeolites (Si/Al – 1–1.5) A, X 2. Intermediate silica zeolites (Si/Al – 2–5) (a) Natural zeolites: erionite , chabazite , clinoptilolite , mordenite (b) Synthetic zeolites: L, Y, omega, large port mordenite 3. High-silica zeolites (Si/Al=10–4000) (a) By direct synthesis: ZSM-5, ZSM-1I, EU-I, EU-2, Beta (b) By then no chemical framework modification: mordenite , erionite , highly silicious variant of Y 4. All silica “zeolite” Si/Al=1000 to ∝ Silicate

26. Characterization of Zeolites Generally, Zeolites are characterized by the help of X-Ray diffraction (XRD), Fourier Transform-Infrared Spectroscopy (FT-IR), Scanning electronic Microscopy (SEM) and BET surface area analyses. XRD:- X-ray powder diffraction (XRD) is a rapid analytical technique primarily used for phase identification of a crystalline material and can provide information on unit cell dimensions. FT-IR:-  FTIR Spectroscopy, is an infrared spectroscopy method used to identify organic, polymeric, and in some cases, inorganic materials. SEM:- SEM provides detailed high resolution images of the sample by rastering a focussed electron beam across the surface and detecting secondary or backscattered electron signal.  BET:- Brunauer –Emmett–Teller  ( BET )  theory  aims to explain the physical adsorption of gas molecules on a solid surface and serves as the basis for an important analysis technique for the measurement of the specific surface area of materials.

27. Powder X-ray diffraction patterns of calcined zeolites (zeolite Erionite, zeolite BETA, zeolite LTL), their ion exchanged forms (Na-Erionite, Fe-Erionite, Cu-Erionite, H-Erionite, Na-LTL, Fe-LTL, Cu-LTL, H-LTL, Na-BETA, Fe-BETA, Cu-BETA, H-BETA) and composites of PANI-Erionite, PANI-LTL, PANI-BETA, PPy-Erionite, PPy-LTL, PPy-BETA are shown below. XRD Spectra of Ion Exchanged Forms of Zeolite Erionite and Composites of PANI-ERI and Ppy-eri

28. XRD Spectra of Ion Exchanged Forms of Zeolite LTL and Composites of PANI-LTL and Ppy-ltl In all the cases the degree of crystallinity is very high rather all the materials are crystalline in nature except composites whose crystallinity is decreased due to amorphous nature of polyaniline and polypyrrole.

29. XRD Spectra of Ion Exchanged Forms of Zeolite BETA and Composites of PANI-BETA and Ppy -beta It was found from XRD that the structure is stable even after calcinations at 550 C for 5 h in a stream of dry air. Of all the zeolites, zeolite LTL has maximum peak intensity for the major diffraction peaks. Therefore zeolite LTL can be considerd to have maximum crystallinity in terms of peak intensity and sharpeness .

30. Fe- Erionite Na- Erionite Cu- Erionite H- Erionite FTIR Spectra of I on E xchanged F orms of Z eolite Erionite and PANI-ERI and PPy-ERI The presence of water molecules attached to zeolite framework is confirmed by a strong characteristic structure sensitive band due to water bending vibrations at 1700-1750 cm -1 . An absorption band at 1500-1600 cm -1 in case of Erionite and zeolite BETA was attributed to ( N-H ) deformation of organic templates TMACl and TMAOH respectively used during their synthesis.

31. FTIR Spectra of ion exchanged forms of zeolite BETA and PANI- BETAand PPy-BETA FTIR Spectra of ion exchanged forms of zeolite LTL and PANI-LTL and PPy-LTL

32. The Surface Morphology Surface morphology of calcined zeolites (zeolite Erionite, Zeolite BETA, zeolite LTL), their H forms and metal ion exchanged forms and composites were obtained by SEM (JEOL JSM 5800, SEM EDAX) instrument. From SEM images, all the three zeolites appear to have relatively non uniform surface, slightly uneven pore morphology and difference in particle size. Zeolite BETA particles appear to be flakes and sometimes as spheres having particle size of 50µm. Zeolite LTL particles appear to be twigs having particle size of 5µm. Zeolite Erionite appear to have rod shaped structure with excellent crystal edges and having particle size of 2µm.

33. PANI-ERI composite Zeolite erionite Zeolite LTL PANI-LTL composite SEM Images of Zeolites and Their Composites

34. Zeolite BETA PANI/BETA composite SEM Images of Zeolites and Their Composites

35. Element Weight % Atomic % C K 55.56 64.21 NK 12.32 12.21 OK 21.39 18.56 NaK 0.20 0.12 AlK 0.30 0.15 SiK 7.21 3.56 ClK 3.02 1.18 PANI- E rionite composite Element Weight % Atomic % CK 7.21 11.09 NK 12.13 16.00 HK 38.70 44.67 NaK 2.41 1.93 AlK 13.48 9.23 SiK 25.69 16.90 KK 0.37 0.17 PANI-LTL composite Element Weight % Atomic % OK 46.24 65.38 AlK 1.76 1.48 SiK 29.35 23.63 CL 13.29 3.43 NK 3.94 2.78 HK 3.02 1.93 KK 0.94 0.55 NaK 1.46 0.82 PANI-BETA composite EDX spectra of zeolite -polymer composites

36. Thermo gravimetric analysis (TGA) samples were first dried at a temperature of 450 C to remove moisture and impurities. TGA was performed by heating the sample from 200 C to 800 C. TGA spectra of all the three zeolites (zeolite Erionite, BETA and LTL) were carried out. TGA of the zeolites was carried out and it shows two steps in weight loss. The first weight loss around 150 C can be assigned to the bound water or oxidant. The second weight loss around 250 C can be assigned to the decomposition of the structure of template.

37. Thermo gravimetric analysis   (TGA) TGA Spectra of Zeolite Na-BETA TGA Spectra of Zeolite Na- erionite TGA Spectra of Zeolite Na- erionite

38. BET surface area analysis (BET)   BET Surface Area and Pore Width of Erionite Brunauer –Emmett–Teller (BET) theory explains the phenomenon of physical adsorption of a gas molecule on the surface of a solid and is used as a basis for the measurement of specific surface area of a material.

39. BET Surface Area and Pore Width of BETA The peaks for pore width are observed between 0.4 – 1.0 nm. According to the definition by IUPAC, the adsorbent pores are classified into three groups: micropore (diameter ˂ 2 nm), mesopore (2-50 nm) and macropore (˃ 50 nm) indicating that the zeolites prepared in this method contain only micropores .

40. BET surface area and pore width of LTL

41. Applications of Zeolites Application of zeolites are in catalysis, ion exchange and adsorption . Catalysis:- Zeolites are extremely useful as catalysts for several important reactions involving organic molecules. The most important are cracking, isomerization and hydrocarbon synthesis. Ion exchange:- Hydrated cations within the zeolite pores are bound loosely to the zeolite framework, and can readily exchange with other cations when in aqueous media. Applications of this can be seen in water softening devices, and the use of zeolites in detergents and soaps. Adsorption:- Zeolites are used to adsorb a variety of materials. This include applications in drying, purification, and separation. They can remove water to very low partial pressures and are very effective desiccants, with a capacity of up to more than 25% of their weight in water.

42. Application of Zeolites in different Fields Zeolites application in field of water purification, waste management, horticulture, catalysis process, anti-oxidant, agriculture etc. Using zeolites waste management can control by catalysis, ion-exchange and adsorption process. Waste materials are as radioactive, toxic gas/ chemicals , Pesticide/ herbicide management

43. Application of Zeolites in Waste Management Novel nanoporous zeolite materials used for the treatment of waste including radioactive, toxic gas/ chemicals separation, Pesticide/herbicide management, sewage treatment etc. Zeolite acts as auxiliary as well as functional support in gas sensing. The modification of zeolite structure increases its sorption capacity, sensitivity and recyclability. The parent sodium form was also modified to proton form to increase their catalytic activity and further applying for organic drug synthesis. Natural microporous zeolites first gained widespread attention in radioactive waste applications after the pioneering research of Ames in the late 1950's. Zeolite-rich rocks can retard, via simple cation exchange, the migration of radionuclides occurring in solution as simple cations (e.g. Cs + , Sr 2+ , and Ba 2+ ).

44. Advances in nanoscale science and engineering suggest that many of the current problems involving water quality could be resolved or greatly improved using nanoporous materials. Currently , the most widely used method for the removal and separation of toxic metal ions/organic compounds is the solid phase extraction technique . Nanoporous materials have unique properties like large specific surface area , high adsorption capacity and low temperature modification, so they are promising solid-phase extractants and have contaminant scavenging mechanisms . Solid Phase Extraction Technique For Waste Management

45. So, our research is concerned with synthesis, characterization and application of nanoporous materials ( zeolites ) for preconcentration , separation and determination of metal ions from industrial waste water. Heavy metal ion contamination such as cadmium, zinc, lead, copper, iron, nickel and cobalt represents a significant threat to the ecosystem. Adsorption is one of the widely used processes for toxic metal removal from contaminated water, since it is a simple and economically feasible method. In this context zeolites are finding tremendous applications for adsorption of metal ions.

46. Radioactive Waste Application High cation-exchange capacities (~2 meq /g), clinoptilolite and mordenite have high selectivities for Cs, Ba , and Sr. The high selectivities of clinoptilolite and mordenite zeolites can sorb Cs, Ba , and Sr from solutions, even when these cations are present in small amounts together with large amounts of other \ competing cationic species. High cation-exchange capacities and their selectivity for Cs and Sr are key in their use in radioactive waste applications. Radioactive Wastes

47. The natural resources for power production are getting exhausted day by day. The consumption of resources for power production is so large that by next decade one will have to depend wholly on radionuclides . However these radionuclides are hazardous to living system. So remediation of these radioisotopes is necessary. Radiation Hazard can be defined as the release of radioactive substances or high-energy particles into air, water, or earth as a result of human activity, either by accident or by design.

48. The sources of radioactive isotopes include: Nuclear weapon testing or detonation. The nuclear fuel cycle, including mining, separation and production of nuclear materials for use in nuclear power plants or nuclear bombs. Accidental release of radioactive material from nuclear power plants . Sources

49. Since, even a small amount of radiation exposure can have serious (cumulative) biological consequences; the radioactive wastes remain toxic for centuries. Radiation Hazard is a serious environmental concern even though natural sources of radioactivity far exceed artificial ones at present. The problem of Radiation Hazard is compounded by the difficulty in assessing its effects. Radioactive waste may spread over a broad area quite rapidly and irregularly (from an abandoned dump into an aquifer) and may show its effect upon humans and organisms for decades in the form of cancer or other chronic diseases.

50. A closed loop of Indian Nuclear Fuel Cycle

51. Half-lives of the order of years to decades of isotopes of elements that can seek tissues or organs biologically (being akin to other elements chemically) are the most hazardous from point of view of radiation. For example, 90 Sr, being chemically akin to Ca, can seek the bone and lodge itself there for years causing radioactive damage to surrounding tissues.

52. The nuclear reactions that are fission of nuclei like 235 U, 239 Pu and fusion of elements like hydrogen result in release of enormous energy and radioactive elements. The nuclear fuel cycle in India begins with the mining of uranium and the processing of mined uranium into U 3 O 8 . The resulting spent fuel is then reprocessed to recover uranium and plutonium. At each and every step of nuclear fuel cycle the different types of nuclear waste are generated. These wastes may be classified into different categories on the basis of their actual level as given below: Potentially active waste (PAW) Low level waste (LLW) Intermediate level waste (ILW) High level waste (HLW Radioactive waste

53. Different levels of Radioactive waste

54. Total nuclear waste generation in India

55. The high level waste (HLW) generated from the reprocessing of spent nuclear fuel contains long lived radionuclides such as, 90 Sr (29 y), 129 I (1.57 x 10 7 y), 137 Cs (30 y), 135 Cs (2 x 10 6 y), 99 Tc (2.1 x 10 5 y) as well as minor actinides. This HLW is proposed to be buried in the deep geological repository after vitrification in a suitable matrix, e.g., borosilicate glass, synroc , etc. However, with time these radionuclides may leach out from the waste and may be released into the natural environment thereby contaminating it. There is strong indication that contaminants can be transported via soil contents like colloids. Most experimental evidence for colloid-facilitated transport of contaminants has been obtained from saturated porous media, either saturated laboratory column studies or groundwater studies. Migration of radionuclide in the Environment

56. The different processes that may control amounts and forms of radionuclide's present in the environment and influence their migration behavior are : Precipitation : It occurs when there is sufficient concentration of the metal ions in solution to exceed the solubility product for the solid phase formation, which causes retarding effect on release and on migration rate. Adsorption : The metal ions may get sorbed onto colloidal particles, coming from weathering of host rocks, present in aqueous phase. The interaction of these elements in the aqueous solution with solid surfaces is generally described in terms of physical sorption, chemical sorption and electrostatic sorption. This may decrease the migration.

57. Complexation : The metal ions have tendency of complexation with different inorganic and organic ligands present in aqueous phase. The predominant inorganic ligands are hydroxide, carbonate, sulphate , phosphate, chloride, fluoride and nitrate, whereas the organic ones are low molecular weight oxalate, citrate etc. and high molecular weight humate and fulvate . Complexation increases the amount of metal ions in solution and hence, having tendency to increase the migration rate . In nuclear waste repositories, carrier colloids will be produced by degradation of engineered barrier materials and waste components: iron based waste package materials can produce iron oxyhydroxide colloids, degradation of bentonite backfills can produce clay colloids and alteration of HLW glass can produce a variety of silicate particulates. The most common colloidal materials in the ground water are hydrous oxide of iron, aluminium and silica as well as organic macromolecules such as humic acid. Inorganic colloids in ground water have shown strong adsorption of the metal ions.

58. Engineered barrier system for radioactive waste repository

59. In order to minimize the leakage of radioactive isotopes from geological repositories, their migration in the environment, hence the harmful effects of radiation, there is a need to search for suitable backfill materials. The backfill materials will act as barrier between the repositories and the rest of the environment. To achieve this goal we are working with the synthesis of such backfill materials and sorbents which may prove to be very effective to act as barrier and thus can save the environment from such harmful radiations . Remedy for Radioactive waste

60. Zeolites are the important clay materials present everywhere in underground water having strong tendency of sorption of radionuclide's as well as toxic metal ions. They have negligible desorption property of metal ions in water which indicate that may be used as the backfill materials in the repository process. Zeolites may be of different types and different size on the basis of their synthesis such as micro porous, mesoporous & nanoporous which in turn affects the sorption behavior of the metal ions. The sorption tendency may be optimized by studying the sorption capacity of the materials in different conditions, hence, may be more beneficial to reduce the migration of radionuclide's in the environment.

61. Fuel Catalytic Cracking Petroleum refinery process in which heavy oil is passed through metal chambers (called catalytic crackers or cat crackers) under pressure and high temperature in the presence of catalysts such as alumina, silica, or zeolites. This boiling breaks up heavy, large, and more complex long- chain oil molecules into lighter, smaller, and simpler short-chain molecules such as those of gasoline. Catalytic cracking cracks low value high molecular weight hydrocarbons to more value added products (low molecular weight) like gasoline, LPG Diesel along with very important petrochemical feedstock like propylene, C4 gases like isobutylene, Isobutane , butane and butane. Main reactions involved in catalytic cracking are- Isomerisation Dehydrogenenation Hydrogen transfer Cyclization Condensation Alkylation and dealkylation

62. Hydrocracking Hydrocracking is one of the most versatile processes for the conversion of low quality feed stocks into high quality products like gasoline, naphtha, kerosene, diesel, and hydro wax which can be used as petrochemical feed stock. Its importance is growing more as a refiners search for low investment option for producing clean fuel. Hydrocracking processes uses a wide variety of feed stocks like naphtha, atmospheric gas oil, vacuum gas oils, coke oils, catalytically cracked light and heavy cycle oil, cracked residue, deasphalted oils and produces high quality product with excellent product quality with low sulphur contents.

63. Adsorption Properties Adsorption (molecular sieve) Adsorption in zeolites is significantly different from adsorption in e.g. silica gel or active coal, which have a broad size distribution of pore sizes, and where the size of the pores are in the range of 10 nm. In zeolites the porosity is determined by the crystalline structure, i.e. the pores are arranged in a regular fashion with only one (or a few) discrete pore sizes. Also the pores have molecular dimensions. The implication of this is the use of zeolites as adsorbents and molecular sieves. Mainly used for water adsorption (very low equilibrium water vapour pressure) Gas (hydrogen?) storage materials Molecular sieving effect due to size limitation imposed by framework structure and cation size and position. Also weaker interactions: N 2 -O 2 separation.

64. Sorption- Zeolite For Pesticide Control

65. It h as been found that the Surfactant - admicellar sorbent gave great pesticide sorption; thus, higher concentration of surfactant has been used to modify zeolite. Surfactant-modified zeolite could adsorb all of the target pesticides while unmodified zeolite adsorb only two pesticides because of hydrophilic surface . All the studied pesticides are slightly polar compounds which disfavor to interact with polar surface of zeolite by electrostatic forces . While slightly polar compounds adsorbed on the admicellar sorbent via partition into hydrocarbon phase of the micelles. The effective retention of pesticides on the Surfactant-modified zeolite was acquired by hydrophobic interaction and π-cation interaction between the aromatic rings in analytes and the quaternary ammonium group in Surfactant (i.e. CTAB). Efficacy of Zeolite for Sorption of Pesticide

66. The high surface area and reusability of zeolite were utilized sufficiently for the sorption of pesticide and slow release minerals. The created sorbent established high sorption capacity resulted from high surface area of material. In addition, the developed system offers cost effectiveness due to the reuse of sorbent material. Other advantages of the developed approach were high enrichment factor, time-saving , and use small volume of the eluent which amount of organic waste was reduced as well .

67. Decontamination of Chemical Warfare Agents Chemical warfare agents are lethal/toxic compounds basically used to kill, injure or harm people as well as other living organisms . They are also hazardous to the environment (i.e. contaminate air, water and land). Therefore, there is increasing interest in the effective detection as well as degradation of these compounds. Nerve agents (organophosphates) have highest toxicity than other CWAs. Nerve agents are basically of two types: G agents (Fluorine or Cyanide containing OPs) and V agents (sulfur containing OPs).

68. Showing detail CWAs Description and their toxic effects

69. Decontamination Methods against CWAs There are three fundamental methods of decontamination of chemical warfare agents- Mechanical decontamination, physical decontamination and chemical decontamination Decontamination methods and their types

70. The chemical reactions applied as chemical decontamination procedures are: Nucleophilic and elimination reactions Electrophilic reactions (oxidations) Thermal destruction Photochemical and radiochemical reactions Different CWAs are degraded by different chemical processes HD gas is degraded by dehydrohalogenation , aerobic oxidation by the help of catalyst, oxidation by using hydrogen peroxide, photo oxidation (TiO 2 have this property). G agents are degraded by two methods: Enzymatic hydrolysis and Non-enzymatic hydrolysis. Enzymatic hydrolysis involve organophosphorous hydrolase enzyme (Microbial degradation). Hydrolysis catalyst yield large amount of acidic products therefore buffer is required to maintain the pH of the reaction in neutral to slightly alkaline range. Non- Enzymatic hydrolysis involves chemical compounds (i.e. iodosylcarboxylates ) that promote catalytic hydrolysis in which nucleophilic substitution and hydrolysis reaction takes place.

71. Chemical reactivity of nanoparticles with CWA simulants For each sample, add 5 μL of CWA simulants and 20 mL of n-hexane into 100 mL Erlenmeyer flask. Consider to the volume and density of CWA simulants, the weights of particles needed for establishing the different weight ratios of CWA simulants : Nanoparticle (1:1, 1:2, 1:4, 1:16 and 1:32) and add to the above solutions. To do a complete reaction between particles and CWA simulants, all samples should be attached to a shaker and shake for a definite period. After that, the presence of the CWA simulants in the samples is to be investigated by the UV/VIS spectrometer/GC-MS.CWA simulants like various Nerve agents, Blister agents and Pulmonary/ Chocking agents will be taken for the study.

72. Ion Exchange Properties The counter- cations in zeolites are mobile, and may easily be exchanged. This results in ion exchange capability utilized e.g. in detergents and in waste water purification Thermal Ion Exchange (TIE)

73. Pharmaceutical Drug Synthesis

74. As a result of different zeolites ( zeolite -β, MCM-41, MOR, Y, ZSM-5, HSZ-360, SAPO-34, HSOD, MCM-22 etc.) diverse pharmaceutically important derivatives which are well known drug intermediates has been reported i.e. tetrahydropyran, quinoxaline, quinoline, quinazolines, coumarins , isopylindole , pyridines, Nopol , Napthalene , Toluidine , carbazone , oxadiazoles , triazole , benzodiazepine, oxazole , porphyrins , calyx- pyrolls , spiro-ketals , anilide , pyrroles ( lamellarin R, Tubulin Polymerization inhibitor), xylidine , pyrazine , piperazine , terpinol , terpinyl acetate, imidazole , styrene, limonine , furfural, xylene , β- pinene , epinephrine, paracetamol , α- pinene , anisole, acridinediol , chromene , dihyropyridine , chalcones etc. Different derivatives obtained were synthesized with the help of these reactions i.e. Friedel craft acylation , Friedlander condensation, Knorr-Paal condensation, Biginelli condensation reaction, Propargylation and cycloisomerisation reaction, Pechmann reaction, Mukaiyama type aldolization , Prins condensation reaction, Carbonyl- Ene reaction, Hantzsch condensation, oxidation reactions, Arylation , Acetoxylation , Nitration, Formylation, methylation , esterification , Vapour phase condensation reaction, Claisen -Schmidt condensation reaction, Fischer ’ s method, Ring shift isomerization , cyclization reaction etc.

75. Gas Sensing Detection of the Gases at Working Places to Prevent Accidents Opportunity for Sensors Working at Room Temp. Advantages Over Other Conventionally Present Sensors Such as Ease of Synthesis, Durability etc

76. Gas Sensing Zeolites Zeolite BETA Zeolite Erionite Zeolite LTL Polymers Polyaniline Polypyrrole Target gases used NO 2 , CO and SO 2

77. Synthesis of Zeolite-Polymer Composites Composites were prepared by dry mixing polymer powder with the zeolites with weight ratios equal to 10, 20, 30, 40 and 50 % (w/w). The dry mixed composites were subsequently pressed into pellets with a diameter of 12 mm and a nominal thickness of 2 mm, using a hydraulic press machine at a pressure of ~280 Mpa Schematic Diagram of Gas Sensing Assembly

78. Hence, adding zeolite to polymer provides adsorption sites for the gas molecules to interact with polymer chains Therefore sensitivity increases. NO 2 behaves like an electrophile ; therefore it is expected to with draw electrons from PANI. PANI/LTL VS NO 2

79. PANI/ERI VS NO 2 PANI/BETA VS NO 2 PANI/ERI VS CO PANI/BETA VS CO

80. PANI/LTL VS CO The sensitivity of PANI towards CO increases from 2.11 to 45.00 % as the CO concentration was increased from 5 ppm to 1000 ppm . When the concentration is increased, more and more CO molecules come in contact with polymer chains and the sensitivity increases. The sensitivity of PANI towards CO increases when zeolite is added to it. Since zeolite is having a porous structure, the gas molecules are provided with high surface area to get adsorbed and interact with polymer chains.

81. PANI/ERI VS SO 2 PANI/BETA VS SO 2 PANI/LTL VS SO 2

82. Sensitivity of PPy and PPy/ zeolite Erionite (Si/Al= 9) composites towards NO 2 Sensitivity of PPy and PPy/ zeolite BETA (Si/Al= 13) composites towards NO 2 Sensitivity of Polypyrrole /Zeolite Nanocomposites Towards NO 2 Sensitivity of PPy and PPy/ zeolite LTL (Si/Al= 3.1) composites towards NO 2

83. Sensitivity of PPy and PPy/ zeolite erionite (Si/Al= 9) composites towards CO Sensitivity of PPy and PPy/ zeolite BETA (Si/Al= 13) composites towards CO Sensitivity of Polypyrrole /Zeolite Nanocomposites Towards CO

84. Sensitivity of Polypyrrole /Zeolite Nanocomposites Towards SO 2 Sensitivity of PPy and PPy/ zeolite erionite (Si/Al= 9) composites towards SO 2 Sensitivity of PPy and PPy/ zeolite BETA (Si/Al= 13) composites towards SO 2

85. Green Chemistry This concept was coined in 1991 by Professor Paul T. Anastas (Yale,U.S.), an organic chemist. Therefore, he is also known as Father of Green Chemistry . To achieve goals of Green Chemistry, Prof. P. T. Anastas and J. C. Warner proposed set of twelve principles. Green Chemistry can be defined as a practice of synthesizing materials in such a way so that they should be safe, non polluting, sustainable and also consuming lesser amount of material and energy during processing.

86. Zeolites and Green Chemistry

87. Conclusion The foremost merits of using Zeolite for various applications are significant and novel due to its competency, environment friendly, recyclable as well as thermally stable properties. Water and wastewater treatment, Radioactive Hazards, Pesticide control, Pharmaceutical drug synthesis, Toxic Gas Sensing, CWA decontamination are the important problems worldwide and there is a wide interest in implementing Zeolites , so zeolites being a good choice to solve various problems taken for research studies. Thus, there is a growing trend for utilization of zeolites for the environmental applications resulting in the reduction of pollution and water contamination.