Pretreatment System

Pretreatment is necessary to:

  • Remove particles that could damage the membranes
  • Reduce the possibility of scale precipitation
  • Eliminate free chlorine

NNSPL is able to furnish the pre-treatment suitable for every requirement. For sizing of plant, it is necessary to obtain and analyze the complete raw water analysis.

We can Supply: Potabilization plant; Oxidation processes for the elimination of heavy metals, Sand and multimedia filters, Activated carbon filters, simple or steam sterilizable;

Zeolyte filters: organic scavengers; 
softeners; chemical dosing system; microfiltration systems; UV lamp.

Particular care is given to the design of pretreatment systems, in order to grant the lowest risk of bacteriological uncontrolled growth.


  • Flexible outputs from 500 Lph to 50,000 Lph
  • Low footprint with optimal accessibility
  • Treatment of any type of microbial contamination like psedomonas, pathogen, e-coli etc.
  • Treatment of any heavy metals like fe, mn, pb, zn, as, f etc.
  • Treatment of any source of water like ground/surface/sea/natural resources/municipal corporation treated water etc.
  • Treatment of any type of toc (suspended, volatile, dissolved), cod, bod etc. from the raw water
  • Customized treatment options based on clients / consultant’s requirement
  • Variants in type of automation like manual / fully automated / semi auto
  • Economical system design & equipment selection
  • Design consideration based on gmp, cgmp, ispe etc. guidelines
  • Minimizes waste generation, reuse & recycle

Process Description: Water softeners remove hardness (dissolved calcium and magnesium) through an ion exchange process. Incoming hard water passes through a tank containing ion exchange resin beads which are super saturated with sodium. As the water passes by the beads, the calcium and magnesium ions replace the sodium ions on the resin and sodium is released into the water. When the resin becomes saturated with calcium and magnesium, a backwash regeneration cycle is instigated. A concentrated salt brine solution (NaCl) is back washed through the resin, replacing the calcium and magnesium ions on the resin with sodium ions
Working Principle: Water is softened by removing the hardness-producing ions, or specifically, the cations of calcium and magnesium. In the ion exchange reaction, sodium is substituted for hardness ions. The anions, bicarbonate, chlorides, sulfates, etc., are not changed in this process.
The symbol Rz refers to the ion exchange resin which is frequently referred to as zeolite. The original zeolites or materials resembling zeolites, which include greensand or synthetic alumino silicate cation exchange materials are very seldom used today because of the more durable and higher capacity styrene-divinyl benzene type ion exchange resins.
Process Description: In ground water or tube well water presence of iron and manganese has always been a matter of concern. Presence of these elements in water does not pose a risk to human health but it can cause unpleasing taste, odor and staining, which is not accepted in most of applications in domestic use as well as commercial and industrial use; therefore, oxidation filtration often knows as iron removal process is employed to remove naturally occurring iron and manganese from water. For this complete iron and manganese removal process an iron removal filter is utilized.
Working Principle: The process through which iron is removed from water is known as Oxidation Filtration that involves the oxidation of the soluble forms of iron (Fe) and manganese (Mn) to their soluble forms and then removal by filtration. The oxidant chemically oxidizes the iron and manganese (forming a particle) and kills iron bacteria and any other disease-causing bacteria that may be present after that the filter removes the iron and manganese particles
Process Description: Activated carbon is used in pretreatment to remove chlorine and chloramines from feed water so they do not damage membrane filters and ion exchange resins. Most activated carbon is produced by “activating” charcoal from coconut shells or coal by roasting at 800 – 1000 °C in the presence of water vapor and CO2. Acid washing removes much of the residual oxides and other soluble material. Activated carbon used in water treatment usually has pore sizes ranging from 500-1,000 nm and a surface area of about 1000 square meters per gramme. Organic fouling can reduce the effectiveness of the carbon.
Working Principle: Activated carbon reacts chemically with 2-4 times its weight of chlorine, producing chlorides. This reaction is very rapid and small carbon filters can effectively remove chlorine from water. The breakdown of chloramines by carbon is a relatively slow catalytic reaction producing ammonia, nitrogen and chloride; larger volumes of carbon are needed. The second application of activated carbon is in the removal of organic compounds from potable water.
Activated carbon takes up water contaminants by virtue of ionic, polar and Van der Waals forces, and by surface-active attraction. Activated carbon beds are prone to releasing fines and soluble components into the water stream and do not remove all dissolved organic contaminants, but their use can produce a significant reduction in TOC. The large surface area and high porosity of activated carbons along with material they trap, make them a breeding place for micro-organisms. Activated carbon beds need to be periodically sanitized or changed regularly to minimize bacterial build-up.
Process Description: Multi-Grade Filter consists of vertical or horizontal pressure sand filters that contain multiple layers of coarse and fine sand (pebbles and gravels) in a fixed proportion. It is a kind of a deep filter bed with adequate pore dimensions for retaining both large and small suspended solids and undissolved impurities like dust particles. As compared to conventional sand water filter, this multigrade filtration system works on higher specific flow rates. It is also a low cost pre-treatment system for ion exchangers (deionizer and softener) and membrane systems such as reverse osmosis etc. With high throughputs, high dirt-holding capacity and capacity to reduce turbidity and TSS (< 5ppm) from water, it protects ion-exchange resins and membranes from physical fouling due to suspended impurities present in the water.
Working Principle: The working principle of a multi grade filter is quite straight forward. In a multi grade filter or pressure sand filter, water is passed through multi layers of filter media consisting graded sand, pebbles and gravels layers. The contaminants in the water are captured in the media bed and filtered water passes into the discharge manifold at the bottom of the tanks. The next and last step is back-washing, a process of effectively removal of captured contaminants from the media bed. After back- washing the filter is rinsed with raw water and after the required quality of water is achieved the filter is put back into service.
Working Principle: Water to be treated is fed into the bottom of the flash/static mix compartment i.e. Flash mixture cum flocculation tank, is divided internally into two compartments clarifier feed pump, where it is thoroughly mixed with chemicals. The partition plate dividing the tank allows the water to pass over to the flocculation compartment. In the flocculation compartment, formation of flocs continues and flocculation is completed. Water containing the flocs passes into the Lamella Plate clarifier. The flow is divided after the water enters the Lamella at the lower part of each sedimentation cell. As the water moves upwards along the inclined plate, suspended solids coalesce to form precipitates which settle at the bottom of the plate. The clarified water continues to flow upward along the plate until it reaches the top of the plate and thereafter flows over the adjustable weird outlet onto the outlet of the Lamella System. The precipitate slides downward into the hopper bottom of the Lamella clarifier system, from where it is periodically removed for suitable disposal