Water Purification Methods for Sewage

Water purification is a critical part of returning water to the environment. Sewage is a byproduct of modern living and the foul effluent must be treated before returning into nature. The outflow of kitchen sinks, toilets and anthropomorphic processes must become clean water before it is released back into the environment. Local wastewater treatment plants perform this modern miracle daily.

Removing Unwanted Materials

• Filtering removes unwanted materials from sewage influent. Large particle filters are made from polymers designed to trap this matter. The materials may have entered the water through open manhole covers, especially when a torrential rain floods streets. These materials are removed and sent to a landfill. Sedimentation is the secondary process after filtration. Turbidity is followed by settling pools to allow gravity to remove larger pieces of unwanted matter.

Large Particle Filters

• These filters are made of polymers to remove unconstrained large particles. These particles often include small pieces of paper, plastics and grass. The filters rely on the physical action of molecules and no chemical processes.

Microfilters

• Microfilters remove small particulates through molecular action. These filters are the last line of defense to block microbes and other plant and animal materials appearing in water. This is critical when human waste is present because it stops the transfer of disease from person to person. Microfilters also are called biofilters because they screen out microbes.

Chemical Filters

• Charcoal and other chemical filters are used to remove chemical contaminants in water. These pollutants include detergents, oil, gasoline, paint and pharmaceutical drugs that end up in our sewage.

Chlorination

• Adding chlorine as a microcide removes harmful bacteria from water before it is released it back into the environment. Chlorination also produces safe drinking water. Chlorination is optional for sewage effluent, but essential for water treatment plants that produce the drinking water for homes. Chlorination is not recommended for treated effluent released back into areas where the chlorine could harm the environment.