PROCESS DESCRIPTION

• Screening: removal of any large floating and suspended solids present in the inflow. These materials include leaves, twigs, paper, rags, and other debris that could obstruct flow through the plant or damage equipment.

• Aeration: The water is supplied with air. This technique aids in the removal of soluble gases like carbon dioxide and hydrogen sulphide, as well as any gaseous organic compounds that give the water an unpleasant flavour. Aeration also helps to eliminate iron and manganese by oxidising them to their insoluble state.

• Coagulation & Flocculation: Chemicals are added to the water supply to enable micro particles and small solids to stick together. Polyelectrolyte, ferrous sulfate, and aluminum sulfate are examples of chemicals used in the water treatment plant process to aid coagulation. Once water has been treated with the coagulation chemicals it enters a tank with giant paddles. These mix the chemicals and water together and enable the micro particles to form into larger pieces that are likely to stick together, making the sedimentation process in water treatment more effective. This process is known as flocculation.

• Sedimentation: The large particles generated during the coagulation and flocculation stages separate and settle once the water reaches the major settling basins. This results in cleaner water for treatment at the treatment facility. The sediments settle to the bottom of the tank, forming a sludge layer that is later removed via sludge thickening and reused on the land.

• Filtration: Filtration is the process where solids are separated from a liquid. In water treatment, the solids that are not separated in the sedimentation tank are removed by passing the water through sand and gravel beds. When the filters are full of trapped solids, they are back-washed. In this process, clean water and air are pumped back up the filter to dislodge the trapped impurities.

• Disinfection: To eradicate any leftover harmful microorganisms, the water is disinfected. Chlorine, either as a liquid (such as sodium hypochlorite, NaOCl) or as a gas, is the most often employed disinfectant (chemical). There are other ways of disinfecting water (e.g., using the gas ozone or ultraviolet radiation).

RAIN WATER HARVESTING

Rainwater harvesting is collecting the run-off from a structure or other impervious surface in order to store it for later use. Catch the rainwater from localized catchment surfaces such as roof of a house, plain and sloping ground surfaces, artificially repaired impervious or semi-pervious land surface etc. It is easy process to collect Rainwater and diverted into ponds, vessels or underground tanks to store for longer periods and to recharge by construction of Rain water harvesting structures in a suitable sites. Broadly there are two ways of harvesting rainwater, namely; surface runoff harvesting and rooftop rainwater harvesting.

CHARACTERISTICS OF RAIN WATER

Theoretically, rainwater is relatively free from impurities but becomes contaminated by pollutants in the atmosphere during precipitation. Presence and the concentrations of organic, inorganic, physical, and biological impurities depend on several factors, such as roof characteristics, meteorological factors, location of the roof, hydrological aspects, chemical properties of the substance, and storage material. Rainwater is slightly alkaline with pH between 7-8. Rain water consists of elements called Total Suspended Solids (TSS) that are not designed to dissolve. These solids include dust, sand, and clay. They remain suspended in water and cause it to become muddy or cloudy which leads to increase the turbidity of water. The turbidity of rainwater is usually greater than 50 NTU.

COMPONENTS OF RAIN WATER FILTRATION PLANT

• Catchments: Surface which directly receives the rainfall and provides water to the system. It can be a paved area like a terrace or courtyard of a building, or an unpaved area like a lawn or open ground. A roof made of reinforced cement concrete (RCC), galvanized iron or corrugated sheets can also be used for water harvesting.

• Rainwater Storage Tank: The catchment water is collected and kept in a collection tank for further treatment.

• Rain Water Treatment: Rainwater may contain pollution, animal excrement and other particles which are harmful to humans, plants and animals. Therefore collected rainwater needs to be treated before it is safe to use . There are two primary steps to rainwater treatment: filtration and disinfection using chlorine or UV light.

• Filtration :

  • The first step of rainwater treatment involves removing sediment and small particles.

  • Rainwater harvested from roofs travels down a pipe into a storage tank or pit. Dense sediment will settle at the bottom of the tank.

  • Sand filtration assists with the removal of coarse suspended solids from water. These suspended solids shall be removed in the sand filter by passing through the five layers of graded sand present in the sand filter.

  • If rainwater is to be used for drinking, further treatment may be recommended in the form of carbon filtration. By passing the water through carbon, taste and odor are significantly improved and also discoloration to a degree.

• Disinfection :

  • Adding chlorine to water is a simple and effective way to disinfect filtered rainwater.

  • Chlorine treatment is an ideal solution for rainwater that needs to be stored for future use.

  • Ultraviolet light is an alternative method of disinfection. It works by disrupting and damaging pathogens’ cells.

  • UV light disinfection requires rainwater to be virtually free of any large sediment. If the rainwater has not been filtered, 'shadowing' can occur, whereby sediment blocks the UV light rays, reducing the effectiveness of disinfection.

  • UV light treated water can be used immediately after it finishes treatment.

• Storage facility: There are various options available for the construction of these tanks with respect to the shape, size, material of construction and the position of tank

Benefits

• Assures Purest Form of Water for Drinking

• Excellent Purification

• Low operating pressure required (higher than MF)

• Lower energy consumption than nano-filtration or reverse osmosis

• Good permeate yield depending on the supply water and membrane choice

• Constant product quality regardless of feed quality

• Compact plant size

• No chemicals required (aside from cleaning)

• Disinfection is achieved by removing bacteria. UF permits viruses, phage, colloids, and macro molecules to be eliminated to some extent.

Applications

• Dairy industry

• Food industry

• Metal industry

• Textile industry

• Pharmaceutical industry

• Chemical industry

• Wastewater treatment and recycling

• Ultrapure water preparation in the electronics industry

• Electrophoretic paint recycling

• Beverage and juice production

• Medical industry

PROCESS DESCRIPTION

Ion-exchange technology may be employed in water treatment and purification in three different ways. Cation-exchange resins can be used to soften water via base exchange; anion-exchange resins can be used for organic scavenging or nitrate removal; and finally, a combination of cation-exchange and anion-exchange resins can be used to remove virtually all ionic impurities present in the feed water via deionization. The purifying process of water deionizers produces extremely high-quality water.

When all the exchangeable hydrogen ions and hydroxyl ions of the cation and anion exchange resins get exchanged with the cations and anions present in the water, the ion exchange resins are said to be exhausted. Then they are regenerated using dilute HCl and dilute NaOH solutions.

Benefits

• Produces water of very low hardness

• Good for high pressure boilers

• Can be used to soften highly acidic or alkaline waters

Applications

• Refinery

• Petrochemical and chemical

• Mining

• Textile

• Power industry

• Pharmaceuticals

PROCESS DESCRIPTION

Below are the basic steps of an industrial reverse osmosis system :

• Pre Filtration : There are two types of prefilters in reverse osmosis systems that filter out bigger particles like sediment and chlorine. The water passes through a sand prefilter, which filters out particles such as dust, dirt, and rust. The water next passes through an activated carbon prefilter, which binds to and eliminates contaminants such as chlorine and volatile organic compounds (VOCs).

• Reverse Osmosis : The water is then passed across a semipermeable membrane, which retains smaller, more difficult-to-remove dissolved solid particles. Reverse osmosis may frequently remove the vast majority of dissolved solids from water.

• Drainage : The following phase is drainage, which sends the eliminated contaminants down the drain after the water has passed through the semipermeable membrane. Contaminants that accumulate on the membrane might reduce its efficacy, therefore this step is critical. The RO system's efficiency is maintained by draining the accumulated contaminants.

• Storage : The last step is to store the treated water until it is needed. The storage container is often a pressurized vessel large enough to contain the treated water without necessitating waste.

Benefits

• Highly Effective at Removing Contaminants

• Produce high-quality water

• No hazardous chemicals required

• Low maintenance

• Environmental friendly

Applications

• Semiconductor manufacturing

• Boiler feed water

• Food & Beverages industry

• Dairy industry

• Pharmaceutical industry

• Lumber/pulp industries

• Ultrapure water preparation in the electronics industry

• Medical industry

• Agriculture industry

PROCESS DESCRIPTION

The water to be treated passes through a bed of the resin. Negatively charged resins absorb and bind positively charged metal ions. The resins start off with univalent hydrogen, sodium, or potassium ions, which exchange with divalent calcium and magnesium ions in the water to form divalent calcium and magnesium ions. Hardness ions replace hydrogen, sodium, and potassium ions released into the water when the water travels through the resin column. More hydrogen, sodium, or potassium ions are released from the resin and into the water as the water becomes "harder." Resins can also be used to remove absorbed carbonate, bicarbonate, and sulphate ions, as well as hydroxyl ions from the resin. In certain cases, both forms of resin might be found in a single water softener.

A water softening plant has mainly two tanks, a mineral tank and a brine tank. These two work in conjunction to remove the minerals from hard water, monitor the flow of water, and periodically clean the system through a regeneration process.

Mineral tank: The softening of hard water takes place in the mineral tank. The hard water is fed into the tank via the water supply line. Water penetrates through the resin beads, depositing calcium and magnesium ions that harden the water. The water runs softly out of the tank and through the pipes.

Brine tank: It contributes in the regeneration of the water softening system. It's a smaller tank located next to the mineral tank. To restore the resin beads' positive charge, the brine tank carries a highly concentrated solution of salt. In the brine tank, salt is supplied in the form of pellets or blocks. These disintegrate in the tank's bottom water. The heavy brine solution is taken out of the tank and flushed through the resin in the mineral tank when the control valve detects that the resin's softening capacity is reducing. The water running through the machine will no longer be softened if the brine tank runs out of salt.

PROCESS DESCRIPTION

Ozonators are devices that intentionally produce ozone gas. The electrical discharge method is the most common energy source used to produce ozone. Extremely dry air or pure oxygen is exposed to a controlled, uniform high-voltage discharge at a high or low frequency. The gas stream generated from air will contain about 0.5 to 3.0% ozone by weight, whereas pure oxygen will form approximately two to four times that concentration. After generation, ozone is fed into a down-flow contact chamber containing the wastewater to be disinfected. The main purpose of the contactor is to transfer ozone from the gas bubble into the bulk liquid while providing sufficient contact time for disinfection.

Benefits

• Disinfection : In many places where ozone is used primarily as disinfectant, indirect improvements in odor or suspended solids removal were achieved. Further easily bio-degradable compounds are produced from the remaining DOC (Dissolved Organic Compounds) in the effluent.

• Oxidation Of Inorganic Compounds : When ozone comes into contact with cyanide, it reacts violently (CN). Because both nitrite (NO₂) and sulphide (H₂S/S₂) react vigorously with ozone, removing them from the effluent is easy. Nitrite is a poisonous substance. Ozone quickly converts Fe²⁺ and Mn²⁺ molecules into filterable Fe (OH)₃ and MnO (OH)₂ .

• Color removal : Ozone is a more powerful and a safer substitute than chlorine for color removal. The best results are achieved when water has been treated to lower BOD, COD and suspended solids (SS) values so that the ozone reaction is primarily for color removal. Color removal efficiency depends on the ozone dosage, the feed's color values, the wastewater type and temperature and water characteristics.

• Improved coagulation & Turbidity removal : Oxidation of dissolved organic materials by Ozone results in polar and charged molecules that can react with Polyvalent Aluminum or Calcium to form precipitates.

• Elevates DO in water : Ozonation elevates the dissolved oxygen (DO) concentration of the effluent. The increase in DO can eliminate the need for reaeration and also raise the level of DO in the receiving stream.

PROCESS DESCRIPTION

UV light disinfects by entering microorganisms and destroying their DNA in UV water disinfection technology. Because DNA plays such an essential part in the activities and reproduction of organisms, deleting it hinders them from being active and proliferating. UV radiation (wavelength 240-280 nm) is also present in very modest amounts in natural sunshine. With the aid of high mercury discharge lamps, also known as UV lamps, the same energy is generated at higher intensities. When exposed to the right amount of UV radiation, no bacteria, viruses, moulds, or their spores can survive. As a result, UV is regarded the greatest method for water sterilisation, and a UV mobile steriliser equipment may be utilised for room sterilisation.

Benefits

• Effective

• Environmental friendly

• Natural

• Economical

• Safe & chemical free

• Easy to manage

Applications

• Wastewater Disinfection and Reuse

• Centralized Drinking Water

• Food and Beverage

• Bio-Pharmaceutical

• Cosmetics

• Swimming pools