Waste water treatment Back

Action Separation
Method Neutralization, sedimentation, air flotation
Purpose Eliminate various amounts of chemicals
Feedstock Brine

Treated water

Product(s) goes to


Refinery waste water typically includes hydrocarbons, dissolved materials, phenols, ammonia, caustic solutions and other process water. Therefore, a series of treatments are mandatory prior to the discharge.

  1. Pretreatment: Gravity (and filtration) is used to separate suspended hydrocarbons, oily sludge and solids in settling ponds. Acidic waste water is neutralized with basic compounds (ammonia, lime or soda ash). Alkaline waste water is treated with acidic compounds (sulfuric acid, hydrochloric acid, carbon-dioxide-rich flue gas or sulfur). Emulsions are heated up to separate the water from the oil.
  2. Sour water stripping: Sour water, water containing sulfur components, is produced in catalytic cracking and hydrotreating processes and shall be stripped. Phenols are removed using solvent extraction. The sour water is then cooled to remove heat and subjected to air stripping to remove any remaining phenols, nitrates and ammonia.
  3. Secondary treatment: Suspended solids are removed by sedimentation or air flotation. Materials with high adsorption properties are added to the waste water to make slurry which is removed by sedimentation or filtration. This treatment process biologically degrades and oxidizes soluble organic compounds by the use of activated sludge or lagoons.

Tertiary treatment: To meet regulatory discharge requirements, specific pollutants must be removed. These types of treatment include chlorination, ozonation, ion exchange, reverse osmosis, activated carbon adsorption etc. Compressed oxygen may be diffused into waste water to oxidize certain chemicals or to satisfy regulatory oxygen content requirements.

DMA 35 Ex

The DMA 35 portable density meter measures the density and concentration of samples on-site within seconds. The intrinsically safe instrument (ATEX-marking II 2 G Ex ib IIC T4) is perfectly suitable for measuring non-petroleum-samples in hazardous areas. Results are given as density, SG or % concentration. The integrated RFID interface enables quick sample identification (e.g. tank number) before measurement. Measured results can be stored and printed or exported to a PC wirelessly via IrDA later on.

0.001 g/cm3

Repeatability s. d.:
0.0005 g/cm3

Measuring range:
0 g/cm3 to 3 g/cm3

Minimum sample volume:
2 mL