Pakistan - Typical Inlet Water

Typical inlet-water design values for preliminary RO design across arid, irrigation, tube-well, flood, and seawater conditions in Pakistan.

Typical RO Design Feed Water - Arid Pakistan

ParameterValue
pH7.8
TDS3,500 mg/L
EC5,500 µS/cm
Hardness650 mg/L as CaCO₃
Calcium180 mg/L
Magnesium95 mg/L
Sodium700 mg/L
Chloride1,100 mg/L
Sulfate350 mg/L
Fluoride2.5 mg/L
Nitrate25 mg/L
Iron0.2 mg/L
Turbidity2-5 NTU

This is presented in the source as a realistic basis for designing a small commercial RO plant (e.g., 250-1000 LPH), while exact pretreatment depends on the specific water analysis.

Canal Irrigation Water - Indus Irrigation System

Typical for Upper Bari Doab, Lower Gogera, Jhelum and Chenab canals.

ParameterTypical Value
pH7.2-8.3
EC150-700 µS/cm
TDS100-450 mg/L
Turbidity5-80 NTU
Hardness80-220 mg/L
Calcium25-70 mg/L
Magnesium10-40 mg/L
Sodium15-80 mg/L
Chloride15-90 mg/L
Sulfate20-100 mg/L
Bicarbonate80-220 mg/L
SAR0.1-1.5
RSC0-1 meq/L
Suitability: Excellent for irrigation; often suitable as RO feed with media filtration and carbon pretreatment.

Agricultural Tube Well - Punjab

ParameterTypical Value
pH7.4-8.5
EC1,000-4,800 µS/cm
TDS650-3,200 mg/L
Hardness250-900 mg/L
Calcium70-220 mg/L
Magnesium35-110 mg/L
Sodium120-700 mg/L
Chloride80-900 mg/L
Sulfate40-450 mg/L
Bicarbonate200-500 mg/L
SAR2-30
RSC0-13 meq/L

In one Punjab study, only 11 of 50 tube-well samples were classified as suitable for irrigation; the remainder exceeded acceptable EC, SAR, or RSC limits.

Typical River Flood Water - Immediately After Flooding

ParameterTypical Range
pH6.8-8.2
EC250-1,200 µS/cm
TDS150-800 mg/L
Turbidity100-2,000 NTU
Total Suspended Solids (TSS)200-5,000 mg/L
Hardness100-350 mg/L
Dissolved Oxygen3-8 mg/L
COD20-150 mg/L
BOD₅5-40 mg/L
Iron0.3-8 mg/L
Manganese0.05-1.5 mg/L
Total Coliform10⁴-10⁷ CFU/100 mL
E. coliPresent (often high)

The defining characteristics are very high turbidity and microbial contamination, while TDS is often only moderate.

Urban Flood Water

ParameterTypical Range
pH6.5-8.5
EC500-2,500 µS/cm
TDS300-1,600 mg/L
Turbidity300-3,000 NTU
TSS500-8,000 mg/L
BOD₅20-150 mg/L
COD80-400 mg/L
Oil & Grease5-50 mg/L
Ammonia1-20 mg/L
Total ColiformVery High
E. coliVery High

Stagnant Flood Water - Several Days After Flooding

ParameterTypical Range
pH6.7-8.5
EC400-2,000 µS/cm
TDS250-1,300 mg/L
Turbidity200-1,500 NTU
BOD₅20-100 mg/L
COD80-350 mg/L
Total ColiformExtremely High
E. coliExtremely High
ColorDark brown
OdorStrong organic odor

Example Design Feed Water - Flood Relief RO Plant

ParameterDesign Value
pH7.4
EC800 µS/cm
TDS500 mg/L
Turbidity500 NTU
TSS1,000 mg/L
Hardness180 mg/L
Iron2.0 mg/L
Manganese0.4 mg/L
COD80 mg/L
BOD₅20 mg/L
Total Coliform>10⁵ CFU/100 mL
E. coliPositive

This represents a challenging but realistic flood-water source requiring substantial pretreatment before RO.

Typical Treatment Train for Flood Water

Typical treatment train for flood water
Typical Treatment Train for Flood Water

Arabian Sea - Pakistan Coast

ParameterTypical Range
pH7.8-8.3
EC45,000-60,000 µS/cm
TDS32,000-42,000 mg/L
Salinity32-38 ppt
Turbidity1-50 NTU (higher after storms)
Hardness5,000-7,500 mg/L as CaCO₃
Calcium350-450 mg/L
Magnesium1,100-1,450 mg/L
Sodium10,000-12,500 mg/L
Potassium350-450 mg/L
Chloride18,000-22,000 mg/L
Sulfate2,500-3,000 mg/L
Bicarbonate120-180 mg/L
Silica1-5 mg/L
Boron4-6 mg/L

Typical Seawater Design Feed

ParameterDesign Value
pH8.1
TDS35,000 mg/L
EC53,000 µS/cm
Turbidity5 NTU
SDI4-6
Calcium410 mg/L
Magnesium1,300 mg/L
Sodium10,800 mg/L
Potassium390 mg/L
Chloride19,500 mg/L
Sulfate2,700 mg/L
Boron4.8 mg/L

Typical SWRO Pretreatment

Typical SWRO pretreatment
Typical SWRO Pretreatment

SWRO Operating Conditions

ParameterTypical Value
Feed Pressure55-70 bar
Recovery35-50%
Salt Rejection99.5-99.8%
Product TDS50-300 mg/L
Energy Consumption2.5-4.5 kWh/m³ (with energy recovery)

Membrane Type

  • Membrane size: 8-inch × 40-inch (8040)
  • Active membrane area: approximately 37-41 m²
  • Salt rejection: 99.7-99.8%
  • Maximum operating pressure: up to ~83 bar

Example Design Report - Arabian Sea Feed

ParameterValue
SourceArabian Sea
pH8.05
TDS36,800 mg/L
EC55,200 µS/cm
Turbidity8 NTU
SDI5.2
Calcium420 mg/L
Magnesium1,310 mg/L
Sodium10,900 mg/L
Potassium405 mg/L
Chloride19,700 mg/L
Sulfate2,750 mg/L
Boron4.9 mg/L
Iron<0.05 mg/L
Oil & Grease<1 mg/L

Expected Product Water

ParameterTypical Value
TDS50-150 mg/L
pH7.2-8.0 (after remineralization)
Hardness40-80 mg/L
Sodium<30 mg/L
Chloride<50 mg/L
Turbidity<0.2 NTU
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