ENVE 420Industrial Pollution Control

Wastewater Sources in an IndustryDr. Aslıhan Kerç

Classification of Wastewaters• Wastewaters from process and operations• Cooling waters• Cleaning of equipment, production areas, buildings• Wastewaters from sub-processes: e.g. Boiler waters (blöf), condensate waters,

regeneration water from softening plants• Wastewater from toilets, baths, cafeterias (domestic

ww characteristics)• Storm water (rain water), drainage

Classification of WastewatersEach source may have different characteristics.

Should we mix them and treat together? Or not?

If ww generated during cleaning process (cleaning of reactors) contain pollutants, they should be considered as process water.

Process waterFlowrates and characteristics vary.Examples:• Metal plating industry: plating baths• Fertilizer industry: Chemical solution tanks• Paint industry: ww generated from cleaning of tanks• Cooling water which is in contact with the pollutants• Stom water drainage from storage areas should be

considered as process ww.

Cooling waterUsed for cooling of raw material, products or

equipment• Closed loop No ww generation (or very

small amount)• Open loop Water is used only once or a

few times, then discharged

H.W. : Cooling water discharge stds

Cooling waterIf the cooling water is not in direct contact with

the equipment, it is not contaminated, generally clean

They may contain small amounts of chemicals used for corrosion control generally negligible. Cause thermal pollution

If the cooling water is in contact with the equipment they may contain pollutants and should be considered as process water.

Cooling waterIn some industries cooling water may contain

toxic chemicals.Example?Metal industry

Cleaning waterSimilar to the cooling waterIf no contamination Maybe considered as

domestic wwIf contaminated Handle like process ww

Wastewater from sub-processesSub-process: Not directly related with

productionCan be classified in process ww according to its

characteristicse.g. Boilers: Does not produce highly polluted

ww may not be considered as an important process in terms of water pollution

In terms of air pollution An important process

Storm water drainageIf collected seperately and does not have

contaminants clean

Domestic wastewaterFrom toilets, baths, cafeteriaThere should be a seperate collection system for

ww of domestic characteristics.If mixed with process ww all together

considered as process ww.