The treatment of complex effluents and water recycling in the petrochemical industry

When producing or drilling for petrochemical products, effluents with very complex substances are generated. The purpose of effluent treatment is also the recovery of materials or, respectively, a reuse / recycling of the water, including ZLD (Zero Liquid Discharge).

This task is not trivial and can often not be fulfilled at reasonable costs by using conventional treatment technologies:

  • “Produced water“ contains, among other things, a high percentage of dissolved solids (TDS) and heavy metals.
  • Persistent long-chain molecules lead to an unfavourable BOD/COD ratio and are difficult to decompose biologically.
  • Toxic substances, such as phenols, cyanides and aldehydes, have a negative influence on the microbes which are supposed to decompose the pollutants biologically.
  • COD peaks and “oil shocks” overstrain conventional biological sewage treatment plants and lead to an exceeding of the discharge limit values.

Nevertheless, the biological treatment of wastewater containing COD is the most economic and sustainable method. By using an intelligent combination with other processes, e.g. membrane technologies, treatment concepts designed for the respective application can be developed to fulfil those high requirements.

WEHRLE has proven this in numerous applications, such as refineries, gas generation, MTBE production, waste oil recycling, emulsion splitting or polymer production. The high-performance processes, developed particularly for critical wastewaters, distinguish themselves by their reliability, the simple operation and an excellent efficiency.