CHAPTER 4

MEMBRANE SCIENCE

4.1. ACTIVATED COCONUT SHELL CHARCOAL MEMBRANE.

4.2. SAP WOOD MEMBRANE.

4.3. WET LAND MEMBRANES.

4.4. COMBINATION MEMBRANE.

4. 1. ACTIVATED COCONUT SHELL CHARCOAL MEMBRANE

4. 1. 1 Introduction:

“A black, gray form of carbon, produced by heating wood or other organic substance in

an enclosed container without air” Present research work is based on easy, cheap methods which

may be useful for common people, hence it is the first simple technique of water

filtration.Charcoal burns better than wood, hence it is superior; hence it was acting as fuel

historically. Since 3750 B. C, Charcoal was used to smelt ores.Sumerians, Egyptians were using

charcoal for the reduction process of ores of Copper, Zinc, and Tin which was used for Bronze

manufacture.For the prevention of various material, charcoal was used, Charcoal was acting as

antibacterial, antifungal in wet situations.For caulking (coating with hot tar) ships, wood tar was

used, which was produced from charcoal. Since 450 B. C, drinking water was used to store in

wooden barrels which were charred (burnt, carbonized), till 16 th

century, the procedure was

continued

Figure.4. 1: Ancient method of charcoal preparation and transport.

Around 1500 BC Charcoal was used for medicinal purpose by Egyptian papyri.The main

role of charcoal is to adsorb unpleasant smell which comes from putrefying wounds and it may

be from the intestinal tracts. Charcoal is rated as category no-1, which is safe, effective tool. As

per FDA, charcoal is used against toxic poisoning.It absorbs poisonous gases, activated charcoal

absorb excess gasses which are formed due to bean and other food products.The gases are also

formed by bacteria, which are absorbed by a charcoal

Carbon an element with a symbol ‘C’ with atomic number 6, atomic weight 12, non

metallic with tetra valency. The Latin word ‘coal’ means carbon, the thermodynamically stable

element. Graphite is an ore of carbon, which is soft, black and good electrical conductor

Diamond other form of carbon, which is hard, transparent and bad conductor of electricity. For

smelting purpose charcoal was used since 1750 B. C, which was obtained from woods,

especially from softwood and hard word.

Following are certain applications where activated charcoal plays an important role.Air

filter in gas masks, purification of gas,coloring of food,purification of gold, extraction of metals,

finishing of metals, plants of nuclear power, solvent recycling, printing in commercial purpose,

treatment of sewage, soil enhancement, soil which become toxic owing to spills of chemicals or

spraying of chemicals,volatile compounds especially organic from paint, aquarium, swimming

pools, municipal as well as domestic water system.If the activated carbon size is smaller than the

rate of adsorption will be high.The activated carbon available in the form of cloth and fibers,

which are used for bio-chemical protective clothing, gloves and socks etc.It is used in wood

dressing, mask protection.

*Biochar:

It is recent charcoal introduced in activated form, which is formed by pyrolysis method

and is in fine granular form.For Biochar, the temperature range is found to be in between 400 to

500 oc.

Iodine number is another basic term which is useful to see level of carbon as many

carbons adsorb smaller molecules. An activity level of carbon is measured by Iodine number;

higher the Iodine number higher is the activity of that carbon, Micro pore content of carbon.

Iodine adsorb into charcoal pore which is an indicator of Iodine numbers, which is one of the

standard measure of water application.Molasses from solution get adsorbed by activated

charcoal.Higher the molasses number, higher the absorption of bigger molecules ranging from

95-600.

Some activated carbons are coated with Iodine, Silver or cations such as Al, Mn, Zn, Fe,

Li, and Ca etc. These coated activated carbons are used to mercaptans, H2S gas for flue gas,

wine, treatment in coal-fire plants etc. These are also called, IAC (Impregnated activated carbon)

and also acting as antibacterial and antiseptic purpose.

*Polymer coating activated carbon (P C A C)

P C A C (Polymer coating activated carbon) is another activated carbon, which is covered

with polymer, which do not block the pores of carbon but makes it smooth and

permeable.Hemoperfusion is the process where blood with large volume is passed through GAC

or PCAC for removing toxics. (Polymer coating activated carbon

Figure.4. 2: Activated charcoal coated with polymer.

Figure.4. 3: Activated charcoal coated with Iodine

*Activated carbons coated with Iodine:

A. C (activated carbon) are mostly divided into following different categories depending

upon their physical characteristics, P A C (powdered activated charcoal) is fine granule of size

near about 0.15 mm to 0.25 mm.Activated carbon is made by crushing or by grinding carbon

particles.Electrostatic force (Vander Waal) is present among the particles of activated

carbon.Alcohol, Glycols, Ammonia fluorine boric acid, Iron, Lithium lead metals do not bind

with activated charcoal. Some chemical treatments, to activated charcoal improve the absorptive

power which is said to be chemisorptions.The chemicals used are H2S, NH3, HCHO,

radioisotopes and mercury, etc..Technical name is activated carbon which is used as an exploited

agent of the 21st century.

Tap water is contaminated with industrial waste, some cancer forming substances such as

nitrogen oxide (NO), SO2 (sulfur oxide) due to this reason many people purify and filter their

water by using charcoal which become safe and tasty. Dirty raw charcoal is not suitable for

boiling purpose, so we should wash it with scrubber without any chemicals, detergents etc.After

washing charcoal should keep in to boiling water for sterilization purpose in an open container,

stainless steel container should be used.Charcoal contain many cavities (pores) where micro-

organisms can be trapped as they live on organic matter as it is present into pores of charcoal

.Once charcoal used for near about 4-6 month it should be crushed into fine powder and can be

spread into garden or soil which can improve soil quality and can be beneficial for crop yield

too.All types of trees manufactures charcoal, but by experiences the people slowly come to know

that harden the charcoal better is the quality of charcoal.Saw dust, bamboo coconut shell, olive

pits, hard woods are used for preparation of charcoal.

4. 1. 2 Membrane Science:

The color of raw sugar is absorbed by charcoal powder. Charcoal has a microcrystalline

graphite particle size which is so small to consider it as an amorphous substance.The crystalline

structure is of hexagonal network shape. Adsorption as well as absorption process depends upon

particle size, surface area, pore structure, acidity (pH), Temperature, etc. Smaller particles are

present in nature as well as in wastewater, which are suspended in water and form clouds. As we

know that colloidal particles carry same charge, hence they never come to each other, as these

practices repel to each other and scattered everywhere in the media and never settle down and

never form large sized particle.We should add some chemicals or follow some physical

technique to help them to settle down, which combines and form large sized particles and which

settle down.Another method is flocculation where high molecular weight compounds attracts or

traps small sized particles and settles at the bottom. (E.g. Starch.)

Al2 (SO4)3. 12 H2O Al aq+3

+ 3 SO4-- +

12 H2O.

SO4—

aq + H2O HSO4 aq + OH

- (Causing pH change)

Ca(OH )2 Ca+ +

+ 2OH-

(Causing pH change)

With the help of alum and lime dirty water can be cleaned. These electrolytes change the

pH value of water.Basic compounds like Ca (OH) 2, Fe (OH) 2 which are the final product of this

reaction settle at the bottom and water become clear with some basic character, generally we

found water with yellow, muddy appearance due to suspension of Iron oxide (FeO) particles and

clinic organic matter present in the water sample. Earliest to 2000 BC Egyptian and Romans

were using such techniques for water purification.Both these impurities are removed by

flocculation and coagulation method.In the sedimentation process heavy particles settle at the

bottom i.e. it is good for dense particle like silt (heavy mass) and minerals, while flotation

process is best for lighter weight particles like algae and colored pigments or particles etc.The

tank which is used should be as big as to settle particles for long period, ideal 4-5 hours so pure

water can easily separated out by long and narrow outlets channels etc.

In aeration process, the air is coming in contact with water where there is exchange of

certain components took place between two phases.Oxygenation is the main aim of aeration, the

other aim is to remove volatile matter H2S, NH3, etc from water sample. Gaseous substances

dissolve in water and form near product, such reaction is called as hydration.

HCl (g) + x H2O H (H2O) X +

+ Cl –

(aq)

H2S H + (aq) + HS

- (aq)

Above reaction is reversible, aeration is dehydration also which results to gases from water. This

type of equilibrium reaction is as per Henry’s law some aeration methods are as follows:

1. Air stripping

2 .Spray aeration

3. Cascade aeration

4. Diffused aeration

5. Multiple-tray aeration

*Filtration;

It is a simple process of removing solids from liquid fluid through porous medium fine

porous, course, medium has been used.In this case artificial filter medium, nets, sand filter etc.

are used.For filtration flow pressure is required which can be obtained by gravity or pressure

applied from external sources.

Activated carbon (A.C), a natural material which is obtained from lignite, bituminous,

wood, coconut shell, etc.Activation is done by steam or by other methods. Different coal has

different adsorption / absorption property. For sweet taste, we can use coconut charcoal.

Activated charcoal is hydrophobic as well as oleophilic. Chlorine along with its various by

products are adsorbed by charcoal.Some volatile compounds are also adsorbed by alachlor

atrazine, benzene, carbofuran, carbon tetrachloride (CCl4), 2,4, D–dibromochloropropane Cis 1-

3 dichloropropylene, toxaphene, chlordane, radon, London, simazine, PCB’ S, Toluene, xylenes

etc. The alachlor is a particular chloroacetanilide herbicide.

4. 1. 3 How to reuse activated charcoal:

The charcoal, which is used for cooking food, in barbecue bit is totally different from

activated charcoal.The absorptive and adsorptive power of activated charcoal is greater than

normal charcoal.The porous form of activated charcoal makes it more beneficial, like backing

out the odors and induce high reactivity, we can reuse activated charcoal for two to three hours

till the pores are completely blocked, blocked or outdated charcoal is washed, Cleaned

thoroughly with hot (steam) water under pressure so that we can achieve pored form of carbon

again,

• Above activated charcoal should be dried fully

• The above charcoal should dry in oven kept above 150 0c, the above charcoal should be

spread in the form layer so that uniform heating will be given.

• The above charcoal should be baked in the above at 150 0c for 1 hour to remove all the

unpleasant odor and impurities if any.

4. 1. 4 How to clean activated charcoal:

A) Used activated charcoal is taken into mesh kitchen strainer and warm water is forced through

it to rinse all the impurities present in charcoal cavities continue the process for 2 to 3 minutes.

B) If you we keep the charcoal near ear we get subtle cracking, popping noise from charcoal. If

we fail to get such noise, then it is useless, we can’t use further. Activated charcoal is somewhat

expensive, so it is better to generate activated charcoal by simple process.

4. 1. 5 How to regenerate activated charcoal:

Activated charcoal is soaked into the solution of hydrogen peroxide about 10% or we can

use distilled water (demonized) water. During this process, we should use gloves for safety

purpose. The mixture is stirred randomly after 15 minutes. Once the solution absorbed by

activated charcoal adds more solution to above and repeat it for two to three times. Final step is

to remove soaked charcoal dry it in sunny area otherwise, for speedy process, put into oven at

220 to 230 degrees Fahrenheit for approx 2 hours.

Activated charcoal has the following applications via absorption of poisonous gases,

infiltration of water, soil improvement and also in case of odor absorption. Activated charcoal is

one of most non toxic substance which can be applied in the medical field. It is derived from

simple wood, charcoal, etc. Charcoal is porous, better absorptive product and can be available in

market, department store, online also, in hardware stores, pet shops etc..

4. 1. 6 How Activated charcoal can be applied for absorption purpose:

It we put powdered form activated charcoal in one pan and put into refrigerator than the

unwanted odor from the freeze is absorbed. We can keep the tray inside till the odor

vanishes.Smelly shoe rack also prevented by keeping charcoal powder (into plastic bags) after

few days smell removed totally.

Basement with musty odors also gets cleared, if we put shallow pan with activated

charcoal in different area. If there is a moisture problem, then continue the application of

charcoal powder is must.If we keep charcoal sachets into bed room closets, garbage pails, living

space which can remove odors, pet odour, smoke, fume, garbage odor even diaper pad odour is

also removed.

Bone char, coconut shells, peat, petroleum coke, olive oil, and coal saw dirt, a raw

material which is used to prepare activated charcoal by an oxidation process by using air/steam

at highest temperature. Charcoal briquettes; Some material which is useful for making activated

charcoal may also used to in making charcoal briquette. Agricultural waste, and other dry

biomass also used in making briquettes. In commercial charcoal the toxins are present, which are

similar to lighter fluid.All types of briquettes are harmful to human being.Briquettes of charcoal

are used as fuel in 3 rd world counties, (poor catogary) owing this reason it becomes expensive,

the charcoal briquettes are used to control odor in garages, closet etc.

People are now days concerned with contaminants, present in their water supply, which

may cause taste, odor problems.The waste water, which is coming from Industries, leaking of

underground storage tank releases the contaminants in the environment and are listed as,

Benzene Chlorobenzene, trichloroethylene,CCl4 (carbon tetra chloride), CH2Cl2 (methylene

dichloride), and Vinyl Chloride. Some examples of pesticides such as Atrazine, which can cause

health diseases, if are above the level of EPA. The activated charcoal (AC) can filter organic

chemicals as well as certain harmless bad smell producing compounds present in water or

drinking water supply.Some quantity of drinking water is infected by chlorine or chloramines,

the organic matter, which is present in water, (drinking or domestic wastewater) reacts with

chlorine (Cl2 to form some compounds like trihalomethane (THMS) as a byproduct.

These by-products may cause cancers. As per EPA the limit of THMS should not be

more than that of 80 ppb.The activated charcoal filtration is good to remove chlorine,

chloramines and some byproducts too.Lead, from old pipe lines, soldering joints comes in

contact with water and can be filtered by charcoal.Not single treatment method is available for

water purification which removes all the contaminant present in waste water sample.Hence we

should treat domestic waste water with combination of two or more combined carbon filter

technique, which still does not remove contaminants at maximum efficiency.

Bacteria and viruses i.e (microbial contaminant) from waste water samples are not

removed by carbon filters, the metallic ions like calcium, magnesium from hard water sample

also not removal by filter, some other ions like fluoride, nitrate and other compounds are not

removed by charcoal filters.There are various filters sediments or (mechanical) filters which are

filtering particles with different size and other are adsorptive or reactive filters which absorb

water contaminants.The contaminants attached to absorbent and held on the surface. The carbon

characteristic is responsible for adsorption efficiency, which is completely depends upon the

nature of particle size, pore size, surface area, density and hardness of absorbent. Adsorption

process also depends upon concentration, a tendency to leave the water, solubility, contaminant

attraction towards the carbon surface.

In order to improve the quality of activated charcoal it is treated with an acid or coated

with some compounds to enhance the removal speed of contaminants from waste water. The

adsorption process depends upon the contact time, the greater contact time leads to more

adsorption i. e, maximum contaminants are removed from waste unwanted water, and the

substance which gives bad taste and odour are removed by adding small quantity of activated

charcoal. Once the adsorption site is reached to its capacity, then it stop its working, where it is

saturated and it will not absorb/adsorb any contaminants.If one of the adsorption membrane is

exhausted then there should be other membrane as an alternative otherwise it will not filter

contaminable water, but it will become more contaminated.If we want the process breakfree we

should use or shut down the water supply after certain time either, we should change filter.Use

two AC filters and cartridges in a series can be a safeguard against the breakthrough. Most

powerful absorbent known is activated charcoal, which is basically solid in nature, which is

made up of pure carbon.

Porous structure is one of the main important characteristic features of carbon. The

surface area available is about 1500 m2/gm. Solutes as well as gaseous components (adsorbates)

adsorb on the surface of charcoal (AC). It is a physical state i. e, there is no chemical reaction

observed between solute and adsorbent. There is vander-waal force present between these

layers, an attractive force that bind solute as well as gaseous particles or molecules. Various

pores which are present in charcoal, they get opened due to steam heat. Inside the AC there are

two type pores micro pore and macro pores.The macrospores or transport pores are responsible

for showing direction or pathway to adsorbates or solute or organic particles towards the

adsorption site.

The macropore size is exceeding to 500A0.Transport or macropore network should be

distributed through carbon particle in order to take particles, waste particles, organic compounds

to smaller pore sites. The pore size of diameter 50 A0 is said to micoropore or also said to be

finest pores which are also said to be adsorption pores which are present inside the carbon

particles where adsorption phenomenon is observed. “Methylene blue adsorption” is one of the

best common parameters which is useful to check the power of adsorption of A. C. The actual

size of methylene blue particle is 12 of which will not adsorb on the charcoal surface as the size

of pore size smaller than 12 Ao, i.e.with better pore size will not give better methylene blue value

and will work or adsorb impure particles with very smaller size too.

4. 1. 7 Applications of charcoal in various fields:

* A, C reduces BOD, COD, Colour from domestic as well as industrial waste water.

* Air, Gas mask, also in purification of drinking water.

* Compressed air moisture from paint shop also gets absorbed by A. C.

* Swimming pool, soft drink plant is dechlorinated by A, C (Activated charcoal)

* Oil from vapours get absorbed and also vapours from stream of gas.

* Insolvent and gold recovery.

* Some dissolved organic impurities are absorbed by A. C.

* It is also used as catalyst carrier in petroleum Refineries. Some industrial gas, CO2 is removed

by AC (activated charcoal). Plasticizer, glycerin, fine chemicals, dyes intermediates are

decolorized by AC. There are many properties of activated charcoal among these properties,

some are explained here which indicates that the AC is versatile.

* High modulus, rigidity, strength, thermal conductivity, chemical resistivity, also non corrosive.

* In whitening the teethes- stain from tea, coffee, some wine or food material adhere to teeth and

teeth become reddish and a bad odor comes from the mouth, but after applying AC powder the

pH is balanced and it improves the oral health. It is also useful to prevent tooth cavities, dirty

smell and other gum related diseases. Small tidbits, plaque, are adsorbed by charcoal and makes

the teeth white (clean).

Another type of charcoal can be made from Bamboo stick, which can filter hard water

sample chlorine chloramines compounds are filtered by charcoal.One most important advantage

of bamboo charcoal is that it mineralized the water. Potassium, magnesium minerals is added to

water. Bamboo charcoal is having fine porous structure. 1 gm high quality charcoal of Bamboo

has greater surface area which is as equal as 3 tennis courts. Working like sponge and absorb

many different impurities into the sponge. Generally filtering ability is greater than wood

charcoal owing to the large number of porous cavities.

4. 2: SAP WOOD MEMBRANE

4. 2. 1 Introduction and scope

Conversion of dirty lake water into drinkable water by using peel is one of the most

important methods to purify waste water sample. Slowly if we pour waste water sample through

this peel (wood), bacteria are trapped, leaving us drinkable water, uncontaminated water. Water

and minerals are absorbed by plants. The cambium ring is present in the plant. Xylem, porous

tissues are present in the tube. Xylem tissue, a younger wood lies in between concentric circles.

These are present in between the bark and central heart wood.

The pit membranes, which are also called tiny pores, are scattered throughout vessel

walls, which allow sap for flow from one to another vessel. The pores which are present are also

trapping air, if these air bubble increased in wood, then it can be spread into xylem also, which

ultimately kill the plant.A small piece of sapwood can filter 99 percent of E. coli from water.

Sap wood is a smooth portion which covers heartwood.The heartwood is the Heartwoodrt which

is hard and central portion of the tree.It contains various materials which deposits and gives

darker colour.

On the contrary sapwood is soft, young outer part of the tree, but lies in between

cambium and heart wood.This layer is permeable, less durable and usually not that much darker

in colour than heartwood.The sapwood is almost creamy white, yellow in colour and 2 to 5 cm

thick. Maximum species shows a clear difference between sapwood and heart wood.

4. 2. 2 Chemistry of wood

From species to species the chemical composition varies, but near about 50% carbon, 6%

hydrogen, 42% oxygen,1% nitrogen, while 1% other elements viz Calcium, Potassium, Sodium,

Magnesium, Iron, Chlorine, and other element are also present in small quantity.Apart from the

water the wood is also composed of cellulose, a crystalline substance.The percentage is 41 to 43,

about 20 % in deciduous while 30% in conifers. It is five members ring which in an irregular

manner. In contrast to cellulose, lignin a very important part wood presents, near about 27% in

coniferous while 23% in deciduous trees.

Sapwood is outermost, living woody portion of the branch or stem. Heartwood is dead

part of the tree. It is a major part of the tree which supports the tree or gives strengthen, as per

earlier discussion sapwood and heart wood can be distinguished by color.Sapwood, a wood

formed under the bark covered by a thin layer called cambium, stem size increases every year,

because of new layer formation.

Tissues:

Tissues are formed from small cells, generally there are two types of tissues, one is

meristimatic and other is permanent tissues. Meristimatic tissues are divided into Apical,

Intercalary, Lateral or cambium, Vascular and Cork etc.While permanent tissues are of two types

Figure.4. 4: Different types of tissues.

One simple and other is Complex.Simple tissues further divided into the parenchyma,

collenchymas and Sclerchyma, while complex tissues are of xylem and phloem. Xylem and

phloem are very important permanent tissues which are helping in the absorption of water and

minerals from the soil.

Parenchyma:

It is a thin walled live tissue with isodiametric cell. Intercellular space is present among

them. Parenchyma is main storage part of the plant.Chlorenchyma is a green part of

parenchyma.Owing to green part it is helpful in the photosynthesis process. If there is space

which may contain large air or maybe an air chamber present in the parenchyma than it is said to

be aerenchyma.Hydrilla is one of the best examples of this type.

Collenchymas:

Similar to parenchyma, a live tissue, but the wall is a thick isodiametric cell. Cellulose is

deposited at certain corners due to which it becomes thick walled, due to this reason the space is

reduced.It is working as mechanical tissue in dicot aerial young organs and also in some

Gymnospermic plants.Generally it is absent in underground parts and in monocots also.

Sclerenchyma:

Cells present in Sclerenchyma is somewhat hard, thick, lignified and is dead tissue.Cells

are very compact due to which there is space observed among the cells. If we take transverse

section the cells are appear to be elongated vertically, polygonal in shape. There is no

protoplasmic content. From the external side cell wall is thick, very hard because of presence of

lignin or deposition of it.Generally all vascular plants contain this type of mechanical tissue.

Complex tissue:

Xylem-It is also said to be wood, it is a vascular tissue with complex structure. Xylem’s

nature is heterogeneous with four different constituents, namely tracheids, vessels, xylem fibers

which are also said to be wood fiber, and parenchyma of xylem also called as wood

parenchyma.Except xylem parenchyma remaining constituents are dead.As these are dead cells

because of presence of wall with hard lignified and the wall is not having any protoplasmic

material.This clearly indicates that only xylem’s living species is xylem parenchyma.

Some functions of xylem are mentioned here.

1. In the plant a strand of vascular is formed with the help of phloem and xylem.

2. As per earlier discussion soil is composed of water and minerals, from that root of plants it is

absorbed it, the xylem which is only the living part of the plant absorb it and transport to the

different parts of the plant body.

3. As we have already discussed about its hardness and lignified nature which make it as one of

the most important mechanical tissue material in the gymnosperms and also in ducts especially

the organs of older parts of the plants.

Trachieids:

It is a main water conducting material in the species pteridophytes and in gymnosperm. It

is present in various vascular plants. The wall present is hard lignified and is tubular, elongated

in shape.Some functions of trachieds are maintained here

1. Water and minerals are conducted by the present cells

2. It is alo useful to give the mechanical support.

Vessels:

Conducts water and highly important and specialized material of the plant. Generally,

these vessels are absent in plants like pteridophytes and also on gymnosperms. Perforated either

completely or partially cross walls or end walls are present in vessels. Lumen observed in a

vessel which is large. A system which is like a pipe is observed in vessels and these vessels are

end to end arranged systematically, so that it can carry or conducts water and minerals very

efficiently in the plant. Some functions of Vessels are maintained here,

1. Similar function like trachieds ie. Conduction of mineral and water

2. It is also useful to give mechanical support.Annular, Spiral, Scalariform; reticulate, pitted are

different parts of trachieds and vessels which are formed due to lignin pattern observed on their

wall.

Xylem fibre:

It is also called wood fibre, it is having a tapering end, which is elongated and also

observed as a dead cell.These are with lignified wall and where there is absent of lumen.The

main function of xylem fibre is only to support which we called mechanical and there is no

conduction observed in this type. Xylem membrane consists of Xylem parenchyma, Primary

xylem, Secondary xylem, which is explained in detail here with their position and

functions.Various thickenings observed in the xylem membrane, which is shown in fig no 4.5.

The thickening is depend on the type of lyer sitiuated in the internal wall of xylem.It is a central

part of the wood, which decides either wood is hard or soft.

Figure.4. 5: Structure of xylem fiber, a tissue present in cambium.

Xylem parenchyma:

It is also called wood parenchyma, one of the important living materials. Cellulose

containing thick or thin walled cell wall which is observed in the present xylem parenchyma.The

main function of xylem parenchyma is to storage the food material only.

Primary xylem:

Embryo originates this xylem, which comes from apical Meristem. Generally observed

in young organ.This xylem is divided into protoxylem (first formed) and metaxylem (later

formed).Following are the various types of primary xylem a) In stem, endarch xylem is

observed b) In root region,exarch xylem is observed c)In Rachis and in leaflets, mesarch xylem

is found.Especially in cycus plant this type xylem is observed.

Secondary xylem:

Vascular cambium activates, at the time of secondary growth and gives this xylem

secondarily.Generally it is observed in older parts of the plant body, especially in the stem, roots,

of type dicot and gymnosperms.This type of xylem is totally absent in the young parts of the

plants.Monocots and Pteridophytes do not show this type of secondary xylem.

Phloem:

Another name for phloem is bast and lepton. It is a tissue useful to conduct food

material.It is one of the tissue which living and complex in structure. Some functions of phloem

are mentioned,

1) A solute or organic food is conducted from the green part of the plant, especially leaf to non

green parts of the plant and stored

2) From the storage region again solute or organic matter is transferred to different parts of the

plant body

3) As a mechanical tissue its role is minor. Following are the important parts of phloem as it is

heterogeneous. a) Sieve tubes, b) phloem fibres, c) companion cells) phloem parenchyma

a) Sieve tube –One of the important materials of the phloem, highly active, efficient, principal,

food carrier part of the plant. Sieve plates which are end walls. These are supported by

particular areas said to be sieved. Strands of cytoplasm vertically interconnected through sieve

tubes with each other. These tubes are very unique and are without a nucleus. Deposition of

cellulose along the walls of these tubes makes them thicker.

b) Companion cells- These are also called sister cell. There is a close association between sieve

tubes and the companion cells. There is a presence of dense cytoplasm in the companion

cell.The cytoplasm is with distinct nucleus.Helps in the function of sieve tubes.

c) Phloem fibre or bast fibre- They have tapered ends with very long cells. As usual due to

deposition of cellulose the wall becomes very thick and so that it can give good mechanical

support.These fibres are not useful in conduction of water and minerals. d) Phloem

parenchyma-These are also called living cells interconnected with phloem material, generally

working as storage material.

Figure.4.6: Structure of phloem fibre, a tissue present in cambium

Similar to xylem, the phloem is also having two types of phloem as primary and

secondary, the primary phloem is present in the younger parts of the plants while secondary

phloem is present in the older parts of the plants.Apical meristem and vascular cambium

originates the primary as well as secondary phloem respectively Dicots and gymnosperm

shows the growth of secondary phloem.

4. 2. 3 Study on pine wood

Karnik’s team worked on pine wood filtration, they concluded that small piece of

sapwood can also filter 99% of E

team collected white pine branches which are stripped off (outer bark), they fix the wood into

plastic tubing, which was sealed with epoxy and secured by clamps.

phloem is present in the older parts of the plants.Apical meristem and vascular cambium

originates the primary as well as secondary phloem respectively Dicots and gymnosperm

shows the growth of secondary phloem.

Karnik’s team worked on pine wood filtration, they concluded that small piece of

sapwood can also filter 99% of E- coil from waste water sample. To check potential, the

llected white pine branches which are stripped off (outer bark), they fix the wood into

plastic tubing, which was sealed with epoxy and secured by clamps.

phloem is present in the older parts of the plants.Apical meristem and vascular cambium

originates the primary as well as secondary phloem respectively Dicots and gymnosperm only

Karnik’s team worked on pine wood filtration, they concluded that small piece of

To check potential, the Karnik

llected white pine branches which are stripped off (outer bark), they fix the wood into

Figure.4. 7: Wood showing cambian ring xylem and phloem and its fixation in tube

(Karnik ref)

Figure.4. 8: Trapped bacteria in a tissue cell. (Courtesy: Google)

4. 2. 3 Neem stick used for water filtration;

*Scientific Classification;

*Kingdom-plantae

*Division-Magnoliophyla

*Order-Sapindales

*Family-Meliaceae

*Genus-Azadirachta.

It is fast growing, reach up to 20 m (about 65 feet) height plant, some time grow up to

131 feet also. It is an evergreen plant. Some time on drought condition it may lose all leaves.

Branches are huge and spread all over. Neem products used in India over two millennia. They

also used as antifungal, antibacterial purpose. Some time some Neem products are used as

antiviral, anti diabetic contraceptive, sedative etc.. Every part of Neem tree used in medicine,

especially for skin diseases.Some part of neem can be used as spermicidal also.

Neem oil used in cosmetic products, in skin care such as acne treatment.For mosquito

repellent neem oil is used.Neem can damage more than 500 types of insects, mites, ticks and

nematodes.It does not kill but can be useful to stop the growth. Neem oil is also used as pest

control. For treatment of chicken pox, Neem leaves are applied. If we take Neem tea, it can

reduce headache and fever.Neem leaves are used as an analgesic, cure fever malaria diseases

Figure.4. 9: Actual photograph secondary Branches of Neem tree.

(Courtesy: Google)

Figure.4. 10: actual photograph Neem twigs, used as sapwood filler.

More than 135 compounds are isolated from different parts of Neem plant. The

compounds which are formed from different parts of Neem plant, are divided into two major

classes.Iso prenoids like diterpenoids and triterpenoids etc., while non isoprenoids are proteins

(amino acids) and carbohydrates (polysaccharide) sulfurous compounds, flavonoides, glycosides,

dihydro chalcone, coumarin, tannin, aliphatic compounds etc.. Nimbidin is a major bitter

compound extracted from oil of seed, tetranortriterpenes, including Nimbin nimbolide, nimbidic

acid has been taken.

Neem compounds show some biological compounds:

*Anti-inflammatory

*Antiarthritic

*Antipyretic

*Hypoglycemic

*Ant gastric ulcer

*Spermicidal

*Antifungal

*Diuretic

*Antimalerial

*Antitumor

*Immunomodulatory etc.

4. 2. 4 Ayurvedic uses of NEEM:

Table. 1 Ayurvedic Applications of Neem plant

Part Medicinal Use

Leaf Skin ulcers Leprosy, eye

Problem, epistaxis

Intestinal worms, anorexia,

Biliousness, skin ulcers.

Bark Analgesic, alternative and

Curative of fever.

Flower Bile suppression,

Intestinal worms and

Phlegm elimination.

Fruit Piles, intestinal worms, urinary

Disorder, epistaxis phlegm, eye

Problem, diabetes, wounds

and leprosy

Twig Cough, asthma, piles, phantom

Tumor Intestinal

Worms, spermatorrhoea

Obstinate, urinary disorder,

Diabetes

Gum scabies wounds, ulcers,

Skin diseases

Seed Leprosy and intestinal worms

Oil Leprosy and intestinal worms

Table.4. 1: Applications of different parts of neem in medicinal field.

Everyday Neem consumption keeps cancer away.Neem has many medicinal uses but if

we consume Neem every day it kill the cancerous cells.Every human bears cancerous cells in the

body, but are not that much organized. The organization of these cells depends upon the

situation created by human being in their body. Collection of these cells at one place can create

a big problem. The cancerous cell keeps under control by Neem consumption. Our body is full of

bacteria, which are present in a body beyond our imagination.Most of the bacteria which are

present in our body are used for digestion purpose without which we can’t survive the life.

Some bacteria which are harmful to body, our body constantly fight with them and spend

maximum energy in defense, when our body fails to fight with them, then we feel down, as our

energy lost against fighting bacteria.By using Neem plant internally as well as externally we can

easily manage these bacteria in such way that it will not go out of control.If we consume Neem,

it destroys troublesome bacteria in the intestinal region, so that our colon will become clean and

will be safe from infection if any.

If the body gets smelted on certain part then it is clear that some bacteria are growing

there. Every one suffers from minor skin diseases, but if we clean out the body with Neem than

it become clean, radiant too, Neem paste rubbing on the body before bathing, keep dry for some

time, wash it, which make the body clean and will act as good antibacterial cleanser.Alternately

we can keep the Neem leaves in water overnight and that water can be utilized for taking bath.

The Neem plant generates heat, which is supportive to generate energy in the body Woman

should avoid to consume Neem during pregnancy period or if she planning to conceive.

Neembark.It is not used as much as its seed and leaves. Slightly used as it is hard, dry. The green

stem part leaves, are used herein filtering membrane so that bacteria virus, can be trapped in it

and filtered water is free from all unwanted bacteria.

Flame of forest –Delonix regia (The Gulmohar tree)

*Kingdom- Plantae

*Angiosperm

*Order- Fabales

*Family- Fabaceae

*Sub- family - Caesalpinioideae

*Genus - Delonix

*Species - D. regia

*Origin –Madagascar

Gulmohar flowers in different month in different country:

Bangladesh – April- may

Hawelli- May-June

South Florida- May -June

Israel- May -June

Manitius- November – December

Honey- Kong- May –June

Zambia and Zimbabwe: October December.

Egypt- May –June

Vietnam- May –June

Thailand- April -May

Caribbean- May- September

Indian subcontinent- April-June

Brazil- November December

Southern Sudan- March –May

Philippines- April-May

Peru- Jan- March

Another name for above plant is built monospermous. Threes trees are available which

are commonly called the flame of forest. These tress belongs to various genera.

1) Butea-monosperma or Palash tree

2) Delonox regia or Gulmohar tree

3) Spathodea or African tulip tree.

Flame of forest-Gulmohar tree, Latin name –Delonix regia Family- Fabaceae. Other

names to this plant are flame tree, flamboyant, gold mohar royal, Poinciama. Gulmohar tree, one

of the beautiful tropical trees on earth.Its height is about 2025 feet maximum up to 50 feet.It is

evergreen, deciduous with highly broad spread branches everywhere like umbrella.During

summer it shades its leaves, but in other season it looks green.Grows well in tropical and

subtropical area.In shaded area it doesn’t grow.Its flowering tree bears red crimson orange, rarer

yellow coloured floured flower.The salty conditions also bear by such type of tree so it can grow

in coastal area also.Large leaves are there, which are doubly pinnate with 20-25 pairs pinnate,

among this each bears 30-60 opposite leaflets.Feathery feel with green color.

The branches which use used in research work are smooth, break easily and can be used

feasibly for research work. The young stem, external bark (some part is cut and some are kept in

long form) and put into membrane so that microbes present into domestic waste water are

trapped into it.The flowers use 5 petaled, out of which one is of different colour.All petals are

claw shaped; this petal has red flecks with white to yellow blotch.These flowers are bisexual and

pollinated by birds.

Figure.4. 11: Actual photograph of Gulmohar tree, (fire of forest).

Mature seed pods; extremely long seed pods flattened with strap shape. It bears near about 50

seeds in each. At maturity, seed turns brown.

4. 2. 5 Applications of Gulmohar tree:

This plant is grown in garden, road side as an ornamental plant.Valuable shade provided

by this plant during summer season.Seeds are useful in artificial Jewellery. Gum which is

obtained from seeds (especially dried seeds) which as used as binder for tablets. E. g paracetamol

etc.. The bark is used in antipyretic medicine.In Thailand inner part of the seed is eaten by

locals.The seeds are useful in medicine as it gives 18 to 30% fatty oil which is known as pangam

or karanga oil of commerce.

In tanning industry, this seed oil is used. The oil obtained from the seed is used as

insecticidal and for antibacterial purpose.Some pharmaceutical industries use oil seed for the

preparation of soap.After use of seed oil, the waste oil cake, which is a side product, can also be

used as fertilizer.As a carminative the seeds are used, which purifies and enrich the blood. In

case of inflammation, ear ache, chest ache oil can apply. For lack insects it is acting as host.

4. 3 WET LAND MEMBRANES

4. 3. 1 Introduction

A constructed wetland is useful to treat waste water sample which is thrown to rivulets by

society after their basic use, but it can be recycled by wetland membrane. The wetland

membrane uses natural vegetation, special quality soil, organisms which are used to treat waste

water sample. The wetland is used to treat pollutants, sediments, heavy metals from water. There

are two types of wetlands one is subsurface flow and other is the surface flow wetland. The

plants which grow on wetland absorb contaminants from waste water sample. The filter bed used

in wetland system may contain sand and gravel too.Root, stem, leaves are the substrates provided

by vegetation on which there is growth of micro-organisms, which are helpful to break down

organic matter.

This micro-organism community is known periphyton.This periphyton and various

chemical reactions which are taking place in the wetland are useful to remove about 90% of

pollutants from waste water sample.We can grow various types of plants into wetland, which

may absorb heavy metals.In the subsurface flow constructed wetland, the wetland is vertical

flow, where waste water after treatment, move vertically through substrate root, and stem etc.

While in case of horizontal, substrate movement is horizontally, parallel to surface.

Figure.4. 12: Constructed wetland for water treatment with wet well, cover

Figure.4. 13: Constructed wetland with different pipe set set up.

Vertical flow constructed wetland is more beneficial then horizontal one, because it

occupies less space.Different waste water sample such as agricultural, house hold, and paper mill

waste water, mining runoff, tannery or meat processing waste etc.Can be treated by wetland

construction methods.The water sample after treatment with wetland filtration can be reused for

irrigation, household toilet, fishing purpose, for street gardening, washing railway platforms,

heavy utensils from Industries (huge boilers) etc.

The effluent which is obtained from base passes through different layers (filter beds) as

grain size is decreased towards the basal side, i.e from the gravel side towards the sand side. This

treatment is based on biological, physical method like adsorption; filtration and

nitration.Mosquito growth is the biggest problem in surface wetland compare to subsurface

wetland where there is no problem of water exposes. The mosquito problem can overcome by

adding Neem sticks, leaves of Neem to the wetland tanks. In order to avoid order some quantity

of ash can be added to the wetland tank. The present research work is based on the subsurface

wetland type as it occupies less space and can be handled by anyone, which can benefit to

society in the future to filtrate their own water and can be reused again.

Figure.4. 14: Constructed wetland without pipes (with gravel setup)

The surface flow wetland is good for wildlife as it requires more land, one more

advantage of this method is there is no sludge formation, and hence there is no problem of

disposal, there is no need of primary and secondary settling tanks also. Free water surface

constructed wetland is also said to be surface flow wetland which is used to treat waste water

effluent, which can also be used to storm water drainage. As water from such wetland is directly

coming in contact with sunlight, so organic matter present in a wastewater sample destroyed

naturally, hence it is called natural decay, which destroys the pathogens also. Direct sunlight

(ultra violet radiation), natural decay, sedimentation destroys pathogens, hence this type of

wetland cannot be selected for present research work, and deep sub surface wetland gives

priority here.

4. 3. 2 Wetlands Science

*Role of wetland plants in wastewater treatment

The plants which grow in a wetland system provide maximum surface area to attach and

to grow microorganism. The components of the plants are playing a vital role in this system,

usually stabilizes surface area of the bed and flow of water is also controlled. It also plays a role

in sediment settling, trapping process, etc. Here water transparency also increases. Wetland

entrophication is prevented by nutrients retention and removal by plants which grow in wetland.

Figure.4. 15: structure of aquatic plant with rhizome (root) used to absorb minerals.

The marshy plants like reed Phragmites karka and cattail Typha angustifolia are excellent

examples which hold or uptake nutrients. This plant shows large biomass both in the leaves as

well as in underground roots, stems. The plant tissues spread or grow vertically horizontally

creates a matrix, which is useful to bind soil particles. Plant tissue contains hollow vessels enable

the oxygen to be travelled from leaves to root and root to soil of surrounding (Armstrong et al

1990; Brix and schierup 1990).

Figure.4. 16: Subsurface constructed wetland with clay, sandy layer.

This oxygen activates microbial activity. The decomposition of organic matter proceeds

fast, owing to oxygen rich substances, metallic ions are absorbed and waste water is cleared.

The wetland plants are performing following function;

*Physical:

Plant bed surface stabilize by macrophytes which provide better condition for filtration

and also gives large surface area for microbial growth, and for sedimentation

*Soil hydraulic conductivity:

In emergent plant bed system soil hydraulic conductivity is improved. Root mass does

turnover owing to which macro pores are formed in the CWTS soil, which is an excellent

process for water percolation, which increases the interaction between effluent and plant.

*Release of organic compounds:

Through root system, plant releases numerous organic compound at a rate up to 20 to

25% of photo synthetically carbon.This carbon is acting as food for denitrifying micro-organism

(bacteria), source (Brix-1997), the plant biomass which are decomposed also act as a carbon

source for microbial activity. Microbial growth of macrophytes provides a large surface area for

microbial growth, which form biofilm for various microbial activity, these films are responsible

for nitrogen oxidation, reduction process.

Figure.4. 17: Aquatic (grass) which can grow in wetland for water purification.

*Creation of aerobic soils:

Nitrification process takes place at root and rhizome level, where aerobic degradation of

organic (biomass) matters taken place. Macrophytes transfer oxygen through hollow plant tissue

Wetland plants are adapted with submerged and lignified layers which are present in outer cortex

and hypodermis which losses least oxygen to the surrounding.

Figure.4. 18: Lotus plant can grow in water for purification

*Constructed wetland mechanism:

In the form of orthophosphate, dehydrated orthophosphate, (polyphosphate) and organic

phosphorus, phosphorus observed in waste water.Owing to biological oxidation process,

phosphorus is converted into ortho phosphate forms (H2PO4-, PO4

-,PO4

---) In the soil media

phosphorus components are mixed, which are removed by certain physico-chemical reaction, viz

adsorption, complexation, precipitation etc., These reactions may involve Ca++

,Fe++

,Se+++

,Al+3

ions.

4.3.3 Nitrogen fixation by wet soil:

The soil, which is under water, is lack of oxygen, which is said to be anaerobic. The

organic matter present in water is decomposed by anaerobic and aerobic microorganism.

Nitrifications, the denitrification process evolves nitrogen. Phosphorus gas, which is co-

precipitated with Al, Mg, Fe, etc.. Bacteria and virus which are harmful reduced due to filtration

and are absorbed by biofilms. Ammonia is removed through wetland treatment, which is

removed from Nitrogen cycle

NH3 (g) NH4+

ion Nitrite Nitrate.

Organic and Inorganic nitrogen containing compounds are converted into a more oxidized

state by biological process by using bacteria.It is a strictly aerobic process which gives the final

product NO (nitric oxide). Ammonia from the waste water sample is converted into nitrogen

oxide. Nitrite is oxidized to nitrate.

Figure.4. 19: Root nodules used in the nitrification process.

*Denitrification:

It is a biochemical reduction reaction, where nitrogen anion is oxidized and converted to

NO, nitrous oxide (N20) with N2. The N20 and N2 are in a gaseous state and enter into the

environment. The algae, which grow in water is the only source of phosphorus, an element

unlike N2. Constructed wetland itself is only part which can remove or store phosphorus from

wastewater samples.

Figure.4. 20: Flow diagram of Nitrification process.

Figure.4. 21: Systematic representation of Nitrogen cycle

*Metal removal:

Wetland constructed is useful to remove metals and metalloids. Generally, these metals

are present in an oxide form and come from mine Industries, storm water, and landfill leachate

etc.

1) How does wetland treatment work?

2) Why to build a wetland treatment (plant);

3) How are they built?

4) Design and planning consideration;

4. 3. 4 How does wetland treatment work?

Both human being and wildlife can get the benefit of wetland construction, as it performs

many functions. Among important functions one of most important function of wetland

construction is water purification.Many suspended particles are settled at the bottom, as they are

trapped by vegetation.Microorganism requires necessary condition which is faster by wetland

plant.The micro-organism removes or transforms pollutants from water sample.From storm

water runoff nutrients such as nitrogen, phosphorus are deposited into wetland, also from area

where fertilizer and manure is spread; various nutrients are absorbed by soil.Wetland, which

contain microbes are useful to convert organic nitrogen into useful inorganic forms like NO3,

NH4 +

which are necessary for plant growth.

4. 3. 5 Why to build wetland:

Wetland is biological natural ecosystem which is applicable in improving water quality

which support wild life habitat.It is cost effective and most feasible method of waste water

treatment, this method has less maintenance expense.It is useful to remove odour from waste

water sample.Habitat creation for compensation to natural wetlands which are useful for

agricultural, urban growth, also improvement in water quality.It is also useful to control flood on

large scale.This system motivates local resource applications,which is environmental friendly.It

is created on lower cost than other treatment process,it is based on low technology method, also

relies on renewable sources of energy. E. g. Solar and kinetic energy, wetland plants, micro-

organism too

This wetland system can consume both small as well as great volume of water which is

coming from sources like municipal and domestic wastewater, urban storm runoff, wastewater

from agricultural, waste water from Industries. Polluted surface water from river, lake etc. The

C. W. T. S. promotes certain potential user's voice, government departments, tourism Industry,

private entrepreneurs, residences, aquaculture Industries and agro industries etc.

4. 3. 6 How are they building?

At large scale if anyone wants to build wetland, then it should away from natural wetland

to avoid damage of natural one.In the past, CWTS (constructed wetland treatment system) were

used to treat low volume of waste water which includes degradable organic matter. The aim of

CWTS is to reclaim and reuse. Now days CWTS are used worldwide for the waste water

treatment purpose. Some countries like the United States, New Zealand and Australia showing

lot of interest in CWTS (Constructed wetland system).While in European countries CWTS are

used for providing secondary treatment especially in village area where domestic sewage

treatment is done. CWTS is energy efficient, economically attractive, and also provide high

standard.