A supernatant relatively clear water which can be used for further processing is made available with the help of clarifiers which remove suspended solids from industrial waste water.

These usually comprise of a circular tank open at the top with a bridge and raking mechanism and a hopper at the bottom. They are classified into (a) Half Bridge peripheral driven (rotating bridge type or (b) Stationary Bridge type, centrally driven, on the basis of capacity and diameter of the tank.
N P C C  has over the years developed expertise, in designing high speed Rectangular Tilted Plate Clarifiers, for various effluents which, besides being economical are also optimum in space utilization.

They have successfully developed robust models of bridge and raking mechanisms of clarifiers to enable acceptance of high loading. The drive is comprised of TEFC motor  and gear box which reduces the high torque speed, and diameter & amount of suspension to be clarified determines the final RPM of the rake arm which ranges from 1 to 10 RPH.

As the name suggests it is a combination of clarifier and the flocculating zone. In order to efficiently carry out process of clarification, to maximize yield, and where there is space constraint besides other consideration, such as direct transfer of the flocculated solids to the clarifying zone with minimal disturbance, is where clariflocculator is preferred.
 

Thickeners are basically clarifiers with a difference i.e. in the torque. The drive and rake arms etc are specially designed for more torque depending on the nature and amount of suspended solids to be handled.
 

 

N P C C successfully designs & manufactures these aerators specific to the imposed conditions and which comprises of, drive unit and TEFC motor of standard makes.
A lot of biochemical degradation is involved to oxidise the dissolved organic matter from organic wastes and to convert them into harmless & viable end products. These  biochemical reactions need seeding, nutrients and mainly oxygen.

This is where the surface aerator plays a major role. It entraps oxygen by agitating the interface as well as the mass of the effluent, so that when the water splashes the dissolved oxygen from the air is entrained . This is then transferred from the absorption side to the main bulk and bacterial colonies that aid these biochemical reactions.

The role of agitator in waste water treatment is very important . This helps to agitate the effluent which invariably is a mixture of water from different invariably is  a mixture of water from different sources, chemicals and flocculants and help to retain the suspended solids therein in a fluidised condition thus preventing their sedimentation.
NPCC acts as a consultant & is adept at selecting the specific agitator suitable for every kind of specialised application and process, from among the standard propeller, turbine, gate & anchor types that they have designed and manufactured. 

Designed to suit even the most corrosive environment the agitators may be of FRP/Rubber lined, unlined, of special material.
The agitator is suspended from a robust hanger on which drive units are mounted consisting of TEFC motor and speed reducers.

Even after undergoing series of chemical treatment, flocculation & sedimentation, the resultant waste water still contains some amount of suspended solids. These are as a result of crushing of flocs, or smaller flocs of a  lighter variety. To get rid the waste water of these, Sand Pressure Filter is most commonly used. It is essentially a cylindrical vessel filled up with fine sand. It comprises of a top water distributor and an under drain system at the bottom for collection of filtered water. 

To facilitate back washing a set of frontal piping and valves are used that enable reversal of flow. These filter units are designed to match the desired flow rate.