Evaporators are widely used in the food processing industry to remove a portion of the water from food products. Similarly, higher-temperature vapor driven out of the product in one effect is used to heat lower-temperature product in another. Efficiency is gained by using multiple-effect systems.

In food processing industries generally triple effect evaporators are used. Since, the vapour temperature of the first effect is the heating temperature for second effect, the temperature difference between the heating temperature of vapour and boiling temperature of the liquid decreases.

Evaporators may be classified into falling film evaporators (in which evaporation takes place from the film interface with no nucleate boiling at the wall), nucleate boiling evaporators (in which wall nucleate boiling occurs over part or all of the heat transfer surface), flash evaporators and direct contact …

There are three major types of desalination plants that dominate the desalination market. These are multi-stage flash (MSF), reverse osmosis (RO), and multi-effect evaporation (MEE).

MEE is widely used for product concentration and has now been used for recovery of water from wastewater which can be reused for industrial operations thus reducing overall fresh water demand of the industry leading zero liquid discharge and sustainable development.

ETP plays an important role in treating industrial wastewater as well as sewages generated from households. Also, expulsion of some toxins is necessary prior to release the wastewater in ETPs. • Results in clean reusable water — ETPs manufactured by any leading packaged ETP manufacturer ensure safe and clean water.

process by bringing together particles to form larger flocs , which settle out more quickly. Flocculation is aided by gentle mixing which causes the particles to collide. Methods: Biological and chemical processes are involved in this level. ➢ To remove, or reduce the concentration of organic and inorganic compounds.

Biochemical oxygen demand (BOD) is the amount of dissolved oxygen (DO) needed (i.e. demanded) by aerobic biological organisms to break down organic material present in a given water sample at certain temperature over a specific time period.

Certain basic or alkaline chemicals used to raise wastewater pH are below: CaO (calcium oxide or lime), MgO (magnesium oxide), Ca (OH) (calcium hydroxide, a hydrated form of lime) or Mg (OH) (magnesium hydroxide) are the most commonly used chemicals because of availability, low cost, and high capacity.

Aluminum sulfate (alum) is the most common coagulant used for water purification. Other chemicals, such as ferric sulfate or sodium aluminate, may also be used.

COD or Chemical Oxygen Demand is the total measurement of all chemicals (organics & in-organics) in the water / waste water; BOD is a measure of, the amount of oxygen that require for the bacteria to degrade the organic components present in water / waste water.

Wastewater with a low pH is generally neutralized using sodium hydroxide (NaOH), lime (CaO), magnesium hydroxide (Mg(OH)2), or calcium hydroxide (Ca(OH)2). Wastewater with a high pH is generally neutralized with sulfuric acid (H2SO4), hydrochloric acid (HC1), or carbon dioxide (CO2).

The process is: {CH2O} + O2 -> H2CO3. Together these processes can neutralize the water so the biodegradation can occur at neutral pH. The resulting water will have a high residual alkalinity of about 33 meq./L so the pH will go up to about 10 if the water is brought in equilibrium with atmospheric CO2.

Chemicals with a pH of 7 are considered neutral acids and typically have a pH less than 7. To neutralize them, use a weak base. There are two types of acids: mineral (inorganic) acids—such as sulfuric, hydrochloric, or nitric—and carboxylic (organic) acids such as formic or acetic.

As a chemical component of the wastewater, pH has direct influence on wastewater treatability – regardless of whether treatment is physical/chemical or biological. Because it is such a critical component of the makeup of the wastewater, it is therefore critically important to treatment.

pH is really a measure of the relative amount of free hydrogen and hydroxyl ions in the water. Water that has more free hydrogen ions is acidic, whereas water that has more free hydroxyl ions is basic. Since pH can be affected by chemicals in the water, pH is an important indicator of water that is changing chemically.

In chemistry, pH (/piːˈeɪtʃ/, denoting ‘potential of hydrogen’ or ‘power of hydrogen’) is a scale used to specify the acidity or basicity of an aqueous solution.

There are three main stages of the wastewater treatment process, aptly known as primary, secondary and tertiary water treatment.

Most wastewater undergoes secondary treatment as well as primary treatment. The most common method is to sprinkle or trickle the water over a bed of sand or gravel. As the water filters downward, it is put into contact with oxygen and microorganisms, which work together to break down the organic matter in the water.

Treatment Steps

• Step 1: Screening and Pumping.
• Step 2: Grit Removal.
• Step 3: Primary Settling.
• Step 4: Aeration / Activated Sludge.
• Step 5: Secondary Settling.
• Step 6: Filtration.
• Step 7: Disinfection.
• Step 8: Oxygen Uptake.