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Oily Wastewater Treatment and Importance of Industrial Wastewater Recycling

12/4/2020

Industrialization over the past several decades has contributed to surface and ground water pollution. Industrial water generally contains oils, surfactants, suspended solids, and metal particles, among others. These industrial residues left in discarded water are prime culprits for contaminating freshwater streams and precious aquifers. Therefore, the treatment of oily wastewater for reuse means eco-friendly, economical, and sustainable.

 

Conventional technologies, such as coalescers and oil water separators (OWSs), which employ coalescing and decantation for oil and water separation, can remove most tramp oil from water if there are no surfactants present. Unfortunately, surfactants, such as detergents and various additives, are commonly found in oily wastewater. These surfactants function as emulsion stabilizers preventing oil droplets from coalescing. As a result, it renders conventional oily wastewater treatment equipment ineffective.

 

Membrane filtration, which is a modern barrier technology, is not affected by surfactant in a process. Through proper selection of a membrane property and pore size, it can effectively separate emulsified oil droplets from water. Due to improvements in material and production in recent years, this technology is commonly affordable and widely accepted in many applications including the oily wastewater treatment provided by FSI’s WRS (Wastewater Recycling System).

 

The processed effluent from the WRS system can meet the government's most stringent requirements for discharge or recycling for reuse. In a typical oily wastewater application, the volume of wastewater is commonly reduced down to less than 10% of the original volume. Most standard WRS systems with a process capacity from 50 gpd (gallon per day) to 4,500 gpd are readily available. Customized systems or systems with process capacity higher than 4,500 gpd can be provided.

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