Desalination through reverse osmosis removes the salts from the water with the help of membrane. These membranes are non porous and allows certain materials to pass through them. The holes in the mesh of reverse osmosis membrane are of the size that allows only water molecules to pass through them, leaving behind the salt molecules. Salt is a prospective by-product of desalination by reverse osmosis. High operating pressure is required to push the water through these membranes.
The system is made up of pre-filter, an activated carbon cartridge and a reverse osmosis membrane. Reverse osmosis used for removing salt and arsenic, most inor-ganic contaminants, bacteria and viruses. 4.4 Chemical treatment (Coagulation-Flocculation): Coagulants and flocculants are chemicals which are made from alum, lime, iron salts, caustic soda, synthetic organic polymers, and natural polymers added to water to remove turbidity and microbes. Coagulants neutralize the charges that forcing them to collide into larger parti-cles called flocs. Flocculants makes flocs into larger clumps for easier removal through filtra-tion.
The main purpose is to prevent contamination of water during its transit from the treatment plant to the place of its consumption. The material which is to be used for disinfection is called the disinfectant and it should be able to give a residual sterilizing effect for a long period. It has been universally recognized that chlorine is an ideal material for the disinfection. 2. MINOR METHODS OF DISINFECTION Following are the minor methods of disinfection: • Boiling method • Excess lime treatment • Iodine and bromine treatment • Ozone treatment • Potassium permanganate • Silver treatment • UV ray treatment 2.1 BOILING METHOD When the water is boiled above a certain temperature, bacteria are killed.
This emulsion breaking is necessary in many practical applications in waste water treatment, environmental technology and petroleum industry. From the presence of interfacial barrier preventing coalescence of the dispersed water droplets, the emulsion stability occurs and the most effective method to overcome this problem is to demulsify the crude by using demulsifiers, chemicals designed to neutralize the stabilizing effect of emulsifying agents. When these surface-active compounds are added to the emulsion, they rupture or weaken the rigid film, enhance water droplet coalescence and migrate to the oil/water
CHAPTER 2 LITERATURE REVIEW 2.1 INTRODUCTION Absorption column is an industrial column that being used to separate solute in the gas and to be absorbed by a liquid. Absorption column is frequently being used in processing of materials, purification and others activities. To ensure smooth and efficient operation, absorption column need to be designed for specific activities (McMahon & Osborne, 2013). A major application of absorption technology is by absorption in solutions of amine or alkaline salts for the removal of CO2 and H2S from natural gas or synthesis gas. Other than that, absorption column can be used to wash ammonia from a mixture of ammonia and air by using water.
It can also be defined as a water-soluble cleansing substance which combines with impurities to make them more soluble. It differs from soap by not forming a scum with the salts in hard water. When a soap or detergent is added to water, the molecules form clusters, known as micelles, in which the polar ends of the molecules are on the outside of the cluster and the non-polar ends are in the middle. The cleansing action of both soaps and detergents results from their ability to emulsify or disperse water-insoluble materials (dirt, oil, and grease) and hold them in suspension in
Mechanism of flotation process Soil washing is a process in which water, with or without additives, mixes with contaminated soil and debris to produce a slurry feed. This feed enters through a scrubbing machine to remove contaminated fine soil particles (silts and clay) from granular soil particles. Radionuclides are generally bound more tightly to the fine soil particles and not to larger grained sand and gravel. It is well known surfactant molecules is contained hydrophobic and hydrophilic regions. The combination of hydrophobic and hydrophilic properties in the same molecule gives these species unique solubility properties in water or aqueous media.
In this process coagulating compounds are added to the water, these compound causes the suspended contaminants to stick to the compound to create bigger particles. Alum and iron salts or synthetic organic polymers (which are either used unaided or in combination with metal salts) are generally used to promote coagulation. - Sedimentation In the process the heavy particles created from the flocculation process are allowed to settle out. -
Sodium hydroxide, a very common base, is another common example of secondary standard. It is very hygroscopic, meaning that it absorbs water from the air, also meaning that its mass basically changes while you 're measuring it. Since it can 't be measured reliably, it can 't really be used as a primary standard. But it can be titrated against a primary standard, and thus can be used as secondary standard. To standardize a solution, a titration is done with primary
The use of oxidation is to remove inorganic contaminants from water Chlorine and potassium permanganate is common oxidant. Coagulants will remove suspended materials from water. Chemicals like aluminium sulphate and sodium aluminates are good examples of coagulants. Filtration is a process of removing suspended or colloidal particles from water by passing water through a filter media. The contaminants will settle on a filter media or adsorb in a filter media.