Overview:

The Iranian Central Oil Fields Company (ICOFC), one of the five major production companies of the National Iranian Oil Company, required a water treatment plant (WTP) to treat raw water from two wells and to produce drinking water and dilution water for desalination units. Napier-Reid supplied a water treatment system including four packages: two Raw Water Sand Filters, Reverse Osmosis (RO) Package, Demineralization Package, and Deaeration Package.

 

Scope of Supply

  1. Two Raw Water Sand Filters (each capacity: 192 m3 per day). Filter vessels, filter internal media, internal supports of the filters, piping system, and instruments.
  2. One complete set of Reverse Osmosis (RO) Package ( capacity: 15.5 m3/day). 2 activated carbon filters, 2 sets of cartridge filtration system (5 microns), 2 high pressure centrifugal pumps, 2 sets of RO membrane module, membrane cleaning system, skid mounting frames, chemical make-up and dosing systems, piping system, and instruments.
  3. One complete set of Demineralization Package (capacity: 145 m3/day). Cation exchanger column, anion exchanger column, degasifier column, forwarding pumps, rinse water system, acid regeneration dosing system, base regeneration dosing system, skid mounting frames, piping system, and instruments.
  4. One complete set of Vacuum Deaeration Package (capacity: 120 m3/day) Deaeration tower, duplex vacuum system, 1 common air ejector, 2 deaeration water pumps, circulation water tank, piping system and instruments.
  5. PLC Control Panel

 

The Treatment Process

The process, including filtration, reverse osmosis, demineralization, and vacuum deaeration, is automatically controlled through a programmable logic controller (PLC) system.

Raw water passes through two sand filters (one in service, one in backwash) to remove 90% of particles, and to reduce total suspended solids to 0.5 ppm. Chlorine and coagulant injection equipment are furnished for pretreatment. Filtered water is stored in 197 m3 filtered water tank for the following two consumption:

  1. Filtered water is pumped to reverse osmosis system to produce drinking water. Feed water with antiscalant added is pretreated with filtration system to remove fine suspended solids. The flow is then pressured to skid mounted R.O. modules. The reverse osmosis membrane is ion selective and allows pure water to permeate through while salts are rejected. After pH adjustment, the effluent is delivered to product water stream.
  2. Filtered water is pumped to demineralization package and deaeration package to produce dilution water. Feed water passes through cation exchange column to remove cations, degasifier to eliminate CO2, and anion exchanger column to remove anions and to make demineralized water. Following demineralization, water passes through a vacuum tower to remove dissolved oxygen. The residual dissolved oxygen is further removed by oxygen scavenging. After being treated with corrosion inhibitor, water is stored in dilution water tank.