How Does a Water Treatment Plant Work?

Nowadays we can get safe and clean water easily. What most of us never see or have to worry about are the steps required to make this water drinkable. Treatment for drinking water production involves the removal of contaminants from raw water to produce water that is pure enough for human consumption without any short term or long term iron and manganese.

So today let's introduce you how does a water treatment plant work. 

Specific treatment processes vary, however a typical raw water treatment facility method can typically embody the subsequent steps:

Raw water intake

Raw water (untreated water found naturally within the environment) will return from several sources, together with rivers, lakes, oceans, or groundwater. Usually, once Associate in Nursing plant attracts within the water from their surface water supply, they pull it in (with pipes or by gravity) through a mesh screen or grate to eliminate the larger objects, like twigs, leaves, and fish. The water is then wired to the most facility wherever treatment begins.

Coagulation

After all the massive objects ar faraway from the raw water supply, varied chemicals ar additional to a reaction tank to get rid of the majority suspended solids and alternative varied contaminants. This method starts off with Associate in Nursing assortment of blending reactors, generally one or 2 reactors that add specific chemicals to require out all the finer particles within the water by combining them into heavier particles that settle out. the foremost wide used coagulates ar aluminum-based like alum and polyaluminum chloride.

Flocculation

When action is complete, the water enters a natural action chamber wherever the coagulated particles ar slowly stirred beside long-chain polymers (charged molecules that grab all the mixture and coagulated particles and pull them together), making visible, settleable particles that tally snowflakes.

Sedimentation

The gravity settler (or deposit a part of the raw water treatment process) is usually an oversized circular device wherever flocculated material and water flow into the chamber and flow into from the middle out. in an exceedingly} very slow subsiding method, the water rises to the highest and overflows at the perimeter of the clarifier, permitting the solids to calm down to rock bottom of the clarifier into a sludge blanket. The solids ar then raked to the middle of the clarifier into a cylindrical tube wherever a slow combining takes place and also the sludge is wired out of rock bottom into a sludge-handling or dewatering operation.

The dewatering method takes all the water out of the sludge with filter or belt presses, yielding a solid cake. The sludge water is place onto the press and runs between 2 belts that squeeze the water out, and also the sludge is then place into a giant hopper that goes to either a lowland or an area that reuses the sludge. The water from this method is usually reused and additional to the front of the clarifier.

Filtration

The next step is mostly running the water overflow into gravity sand filters. These filters ar massive areas wherever they place 2 to four feet of sand, that could be a finely crushed silicon dioxide sand with jagged edges. The sand is usually put in within the filter at a depth of 2 to four feet, wherever it packs tightly. The feed water is then had, trappings the particles.

On smaller industrial systems, you would possibly accompany a packed-bed pressure transmission filter versus gravity sand filtration. Sometimes, betting on the water supply and whether or not or not it's lots of iron, you'll conjointly use a inexperienced sand filter rather than the sand filter, except for most half, the sharpening step for standard raw water treatment is sand filtration.

Ultrafiltration (UF) also can be used once the clarifiers rather than the gravity sand filter, or it will replace entire clarification method altogether. Membranes became the latest technology for treatment, pumping water directly from the raw water supply through the UF (post-chlorination) and eliminating the whole clarifier/filtration train.

Disinfection

After the water flows through the gravity sand filter, succeeding step is usually medical aid or chlorination to kill the bacterium within the water.

Sometimes this step is completed upstream before filtration that the filters ar disinfected and unbroken clean. If your system utilizes this step before filtration, you'll ought to use a lot of disinfectant . . . this fashion the filters ar disinfected and unbroken free from bacterium (as well because the filtered water). once you add the Cl up front you’re killing the bacterium and have less fouling. If bacterium sits within the bed, you would possibly grow slime and ought to backwash the filters a lot of usually. thus it all depends upon however you’re system operates . . . whether or not your system is about up to chlorinate upstream (prior to filtration) or downstream (after filtration).

Distribution

If the raw water treatment is being employed in Associate in Nursing process, it’s generally wired into a holding tank wherever it are often used supported the strain of the power. If for municipal use, the treated water is typically wired into a distribution system of water towers and varied assortment and distribution devices in an exceedingly loop throughout town.

Utech has over 20 years of experience helping our customers design and custom drinking water treatment system. If you have any questions, please visit our website for more information about water treatment here.