EAT 207 WATER SUPPLY ENGINEERING Advanced Water Treatment

EAT 207 WATER SUPPLY ENGINEERING Advanced Water Treatment Fahmi Muhammad Ridwan SCHOOL OF ENVIRONMENTAL ENGINEERING UNIVERSITI MALAYSIA PERLIS 2012

Content q Introduction to advanced water treatment q Water Softening - Lime-Soda Ash precipitation - Ion Exchanger q Adsorption q Desalination Special Topic: Reverse Osmosis q. Iron and Manganese Removal q Flouridation and Deflouridation

Introduction to Advanced Water Treatment Advanced water treatment process is proposed: v. To treat water that has undergone treatment by conventional process, so that higher water quality will be obtained v. For industrial purposes, such as steam production and the manufacturing of food, paper, textiles, etc. v. To reduce chemical content in water such as removal of iron and manganese, hardness causing ions, organic & inorganic compounds and minerals.

Water Softening v Softening is the process of removing hardness ions v In general, water is softened using: chemical precipitation and ion exchange v Water hardness is due to the presence of multivalent cations, mostly calcium and magnesium v In natural waters, other ions that may be present to cause hardness but not in significant amounts are iron (Fe 2+), manganese (Mn 2+), strontium (Sr 2+) and aluminum (Al 3+) v When these cations are associated with the carbonate and bicarbonate ions in water (e. g. Ca(HCO 3)2) the type of hardness is called carbonate hardness; otherwise is called non-carbonate hardness (e. g. Mg. Cl 2)

Hardness cations & associated anions

Hardness Classification

Softening by Chemical Precipitation

Softening by Chemical Precipitation

Softening by Chemical Precipitation

Softening by Chemical Precipitation

Softening by Chemical Precipitation

Softening by Chemical Precipitation

Example 1

Water Softening Process

Lime-Soda Ash Softening Components

Typical Single-stage Softening with Recarbonation

Typical Single-stage Softening with Recarbonation

Two stage Softening with Recarbonation

Two stage Softening with Recarbonation

Water Softening Outcomes

Water Softening Outcomes

Ion Exchange

Ion Exchange

Softening by Ion Exchanger

Ion Exchange Regeneration