What Are The Water Purification Processes Environmental Sciences Essay

While the major portion of the Earth is covered with H2O in the signifier of oceans, seas, rivers, and lakes, such H2O is natural and non suit for human ingestion. It has to be purified by taking chemicals and other drosss that contaminate it. In about all parts of the universe, natural H2O from lakes and rivers is purified by Water Purification Plants. In a few planetary countries { notably Gulf states like Saudi Arabia and Kuwait } where there are no rivers, ocean and sea H2O is purified by Desalination Plants.

I. River/Lake Water Purification Process

There are 8 engineerings that are used in the procedure of sublimating natural H2O from rivers and lakes.

1 ) Distillation

This engineering involves heating H2O to boiling point. The H2O vapour which is given out is directed to a capacitor where chilling H2O Acts of the Apostless on it to convey down the temperature and do it to distill, where it is gathered and stored. A bulk of the contaminations stay behind. Distillation is good as it is reclaimable and separates a big assortment of contaminations from pure H2O. Its drawbacks include heavy ingestion of electricity, demand of painstaking care to vouch H2O pureness and the possibility of a few contaminations being transferred into the H2O ( 2,1 ) .

2 ) Ion Exchange

This engineering involves ephemeral H2O through bead-shaped rosin stuffs during which ions in the H2O are substituted for other ions attached to the beads. The two ion exchange engineerings often used are softening and deionization. The first is utilised mostly as a pre-treatment technique to diminish H2O hardness where in the 2nd Na ions are substituted for each Mg or Ca ion taken from the H2O. The latter involves the usage of cation and anion money changers ; in the cation money changer, beads made of cinnamene and divinylbenzene with sulfonic acid content replacement H ions for any cations { organic bases } found in the natural H2O, while in the anion money changer, beads made of cinnamene with quaternate ammonium content replacement hydroxyl ions for any anions { organic acids } found in natural H2O. The H and hydroxyl from both money changers so join to give pure H2O. The benefits of ion exchange deionization include effectual separation of soluble inorganic contaminations, ability to regenerate and low capital investing. Its drawbacks include inability to decently separate contaminations such as bacteriums and pyrogens, heavy long-run operating costs and possibility of cation and anion exchange beds bring forthing civilization bacteriums and bantam pieces of rosin ( 2,2 ) .

3 ) Carbon Adsorption

During the ion exchange engineering procedure which separates cations and anions from natural H2O, a 3rd type, called nonionized contamination, covers the surface of the bead-shaped rosins. This action, called ‘resin-fouling, ‘ reduces the length of service of the rosins and undermines their map. Carbon filters are put in an upstream place to safeguard the ion exchange rosins by dividing nonionized contaminations through a procedure called C surface assimilation. This procedure is regulated by the diameter of the bantam holes in the C filter, and by the gait of organic molecules go throughing through the pores. The benefits of C surface assimilation include drawn-out life span characterized by high capacity and effectual separation of Cl and soluble organic contaminations. It is disadvantageous because it can bring forth C mulcts ( 2,3 ) .

4 ) Micro-porous Membrane Filtration

This engineering involves use of 3 sorts of micro-porous filters. Depth filters, made of tight matted fibres that entrap atoms by irregular surface assimilation, are employed as pre-filters due to their ability to divide 98 % of drifting atoms. Surface filters, made of several media beds that separate contaminations, are besides employed as pre-filters due to their ability to divide 99.99 % of drifting atoms. Screen filters, patterned like a screen, separate all atoms bigger than the specifically regulated pore size on the top bed. The benefits of micro-porous membranes are their demand for really small care while expeditiously dividing all contaminations larger than the pore dimensions. Their drawbacks include the inability to divide dissolved contaminations, their comparatively high cost and their inability to renew ( 2,5 ) .

5 ) Ultra-filtration

This engineering separates dissolved contaminations which micro-porous membrane filtration is unable to take. Ultra-filters are strong, slender, spoting permeable membranes that entrap supermolecules { such as colloids and pyrogens } bigger than a specific size ; those smaller than that { such as dissolvers } are permitted to come in the filtrate. The benefits of ultra-filtration are its ability to renew, its capableness to divide about all atoms, pyrogens and colloids larger than their rated size and its ability to give best quality H2O with minimal sum of energy. Its lone drawback is its inability to divide dissolved inorganic contaminations ( 2,6 ) .

6 ) Reverse Osmosis

Rearward Osmosis { RO } involves the usage of membranes with a tighter pore construction as compared to ultra-filtration membranes, which enable the remotion of about all atoms, beings, pyrogens and organics less than 300 John daltons molecular weight. Natural osmosis takes topographic point when solutions holding 2 differing sums of dissolved substances are separated by a membrane. Osmotic force per unit area so pushes H2O through the membrane, doing it thin the more concentrated solution ( 2,7 ) . By so using contrary osmosis, force per unit area is applied on the side holding the concentrated solution to force the H2O molecules through the membrane to the side incorporating the fresh H2O ( 1,1 ) . The benefits of RO include the demand for minimal care and its ability to divide all sorts of contaminations to a certain grade. Its lone drawback is its restricted flow rates ( 2,7 ) .

7 ) Electro Deionization

This comparatively new engineering involves a faculty holding several cells { located between 2 electrodes } which contain polypropene frames holding cation and anion permeable membranes on both sides with ion exchange rosins in the center. As the provender H2O enters the faculty, the ion-exchange resins entrap dissolved cations and anions which are dragged through the membrane in the way of the cathode and anode severally when current is passed through the faculty. When they reach the next ion-selective membrane, the existent antonym charges prevent the cations and anions from traveling all the manner to their several electrodes. This precludes farther meeting of ions which are alternatively made to garner in the center of the cell { called the ‘concentrate channel ‘ } from where they are forced out into the drain. As H2O travels down the channel that runs through the center of ion exchange rosin bed { called the ‘dilute channel ‘ } it is subjected to gradual deionization which finally splits H2O into H+ and OH- which revitalizes the ion exchange rosins. Electro Deionization is good due to its low operating costs, ability to expeditiously divide dissolved organic contaminations and its non-polluting and safe characteristics. Its lone drawback is its pre-purification demand ( 2,7 ) .

8 ) Ultraviolet { UV } Radiation

This engineering involves sanitation of H2O by 254 nm UV visible radiation produced by quicksilver low force per unit area lamps which cause inactivation of microorganisms nowadays in H2O. A latest Ultraviolet engineering has come up with lamps that produce both 185 nanometer every bit good as 254 nm UV visible radiation which is able to diminish the Total Organic Carbon { TOC } content in extremely purified H2O to merely 5 ppb. UV radiation benefits include efficient sanitation of H2O and oxidization of 185 nanometers and 254 nm organic compounds to 5 ppb TOC. Its drawbacks include its inability to separate contaminations like colloids and its inclination to cut down electric resistance ( 2,8 ) .

9 ) Unifying them all in a Water Purification Plant

Since each of the predating 8 H2O purification engineerings separates a typical sort of contamination, none can be depended upon to divide all contaminations. An efficient H2O purification works use a series of purification engineerings in proper sequence to bring forth the best H2O quality ( 2,9 ) .

The first phase includes pre-treatment equipment { such as C filters and softening agents } to separate contaminations in feed H2O. The 2nd phase is RO – the karyon of the Plant – which separates between 90 to 99 % of contaminations. The 3rd phase is the storage container into which H2O is gathered. The 4th phase is the sublimating systems which purify the H2O { doing it ‘Type I ‘ or ‘ultrapure ‘ } by dividing hints of any contaminant residue ( 2,10 ) .

The proper standardization of purification engineerings and effectual pre-treatment serves to preduce pure H2O that no longer contains ionic, organic or microbic contaminations.

II. Ocean/Sea Water Purification Process

The dense content of ocean or sea H2O { salt } along with other contaminations is removed by the Desalination procedure.

1 ) Desalination Plants

While desalinization of H2O can be done by utilizing the RO engineering ( 1,1 ) , RO workss have become out-of-date and replaced by the much more productive Multi-Storage Flash Distillation { MSF } desalinization workss. MSF workss soon produce more than 85 % of planetary desalinated H2O ( 3,3 ) .

The MSF procedure involves using steam to heat tubs inside seawater warmers. This causes the incoming ocean or sea H2O to be heated, after which it travels into a low-pressure container where it rapidly boils and turns into steam. Heat money changer tubings cooled by inflowing provender H2O so condense the steam into H2O, which is so re-mineralized to do it pleasant ( 3,4 ) .

The Kingdom of Saudi Arabia is the largest planetary manufacturer of desalinated H2O. The desalinated H2O, which supplies 70 % of the state ‘s national H2O demands, is produced by 30 workss including the Shoaiba Desalination Plant which is the biggest in the universe ( 3,4 ) .

III ) Work cited

Helmenstine, Anne Marie. “ Rearward Osmosis. ” About.com. 2009. 14 Dec. 2009.

& lt ; hypertext transfer protocol: //chemistry.about.com/od/waterchemistry/a/reverseosmosis.htm & gt ;

“ Purification Technologies. ” H2ro.com. 14 Dec. 2009.

& lt ; hypertext transfer protocol: //www.h2ro.com/_Solutio2.htm & gt ;

“ Shoaiba Desalination Plant, Saudi Arabia. ” Net Resources International. 14 Dec. 2009.

& lt ; hypertext transfer protocol: //www.water-technology.net/projects/shuaiba/ & gt ;


Title: Water Purification

River/Lake Water Purification Process


It involves heating natural H2O and so distilling it into pure H2O by chilling.

Its benefits are reusability and remotion of big assortment of contaminations.

Its drawbacks are heavy energy usage, heavy care and residue contaminations.

Ion Exchange

It involves interchanging ions in H2O for other ions attached to bead-shaped rosins.

Its benefits are low capital, revival ability and effectual contamination remotion.

Its drawbacks are runing cost, inability to all contaminations and unwanted residues.

Carbon Adsorption

Carbon filters are used to take nonionized contaminations.

Its benefits are long life and effectual remotion of Cl and other contaminations.

It is disadvantageous because it can bring forth C mulcts.

Micro-porous Membrane Filtration

Depth, Surface and Screen filters are used to take about all floating contaminations.

Its benefits are minimal care and efficient remotion of bantam drifting atoms.

Its drawbacks are high cost and inability to regenerate/remove certain contaminations.


It uses ultra-filters to take dissolved contaminations.

Its benefits are less energy usage and ability to regenerate/remove most contaminations.

Its disadvantage is its inability to take dissolved inorganic contaminations.

Rearward Osmosis

It removes about all contaminations less than 300 John daltons molecular weight.

Its benefits are less care and ability to take drosss to a certain grade.

Its lone drawback is its restricted flow rates.

Electro Deionization

It uses a faculty incorporating several cells to take cations and anions.

Its benefits are low runing cost and ability to take dissolved organic drosss.

Its lone drawback is its pre-purification demand.

Ultraviolet Radiation

It involves sanitation of H2O by 185 and 254 nm UV visible radiations.

Its benefits are effectual H2O sanitation and organic compound oxidization to 5 ppb.

Its drawbacks are resistivity decrease and inability to take certain contaminations.

Unifying them all in a Water Purification Plant

An efficient works uses a series of purification engineerings in proper sequence.

It employs the purification engineerings in 4 different phases to sublimate H2O.

Proper amalgamation of engineerings and effectual pre-treatment outputs pure drinking H2O.

Ocean/Sea Water Purification Process

Desalination Plants

Salt and other contaminations are removed by MSF desalinization workss.

MSF workss soon produce over 85 % of the universe ‘s desalinated H2O.

Saudi Arabia has 30 desalinization workss including Shoaiba, the universe ‘s biggest works.

Table of Contentss

Introductionaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ 1

I. River/Lake Water Purification Process aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦.. 1

1 ) Distillationaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ . 1

2 ) Ion Exchangeaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ . 1

3 ) Carbon Adsorptionaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ 2

4 ) Microporous Membrane Filtrationaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ 2

5 ) Ultrafiltrationaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ 3

6 ) Reverse Osmosisaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦.. 3

7 ) Electro Deionizationaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ 4

8 ) Ultraviolet Radiationaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ … 4

9 ) Unifying them all in a Water Purification Plantaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦.. 5

II. Ocean/Sea Water Purification Processaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ 5

1 ) Desalination Plantsaˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦aˆ¦ . 5

III. Work cited