ODOR IN WASTEWATER TREATMENT PLANTS

ODOR IN WASTEWATER TREATMENT PLANTS

Sulphate concentration in domestic waste water varies between 20 - 100 mg / lt. Sulphate (SO4-2) in wastewater is converted to sulfur under anaerobic (in the absence of oxygen and nitrate) conditions (in the absence of oxygen and nitrate) by using the oxygen in the sulphate as the oxygen source for the biochemical reaction by sulphate reducing bacteria. The sulfur ion reacts with the hydrogen ion in the environment and hydrogen sulfide gas is formed. These reactions occur more rapidly during the summer months. Biochemical reactions in wastewater increase with increasing temperature. Especially in places where wastewater is discharged to streams and open channels, and due to the increase in turbulence in sewers and the decrease in the solubility of hydrogen sulfide in water during the summer months, a serious odor problem occurs.

Hydrogen sulfide is a colorless gas under normal conditions. Hydrogen sulfide gas is a highly toxic, volatile, colorless and flammable substance. Hydrogen sulfide gas is 20% heavier than air. Therefore, it accumulates in besieged areas and ground pits where there is not enough ventilation and therefore sinks to the bottom. An explosion occurs when the hydrogen sulfide concentration in the environment reaches 4.3% -46%. The solubility of hydrogen sulfide in pure water at 20 oC is 2.7 liters H2S / lt. With one degree increase in water temperature, the solubility of hydrogen sulfide in water decreases by 2.5%. It creates danger by accumulating in channels, pits, reservoirs and similar areas. Especially in calm weather, intense hydrogen sulfide gas accumulation occurs in places where pollution occurs.

If organic based solids in wastewater remain in the sewage system for a long time, the hydrogen sulfide gas concentration may rise to 6000 ppm in the channel. When the organic solids in the waste water are dispersed, the gas immediately dissipates and the hydrogen sulfide concentration drops.

PUR-6000-PPF ODOR CONTROL SYSTEM