Recycling Phenolic Wastewater from Phenol-Formaldehyde Resin Production

The sorption Phenolic wastewater is a kind of hazardous waste due to the presence of free phenol which is a highly toxic organic compound. Described in the literature and implemented, technology solutions for dephenolization are commonly based on thermal destruction. However, thermal treatment technologies have a range of disadvantages and the main ones of them are the losing of phenol and formaldehyde, which are valuable chemical raw materials and changing the balance of atmospheric oxygen and carbon dioxide. At the same time, owing to bonding properties, phenol and formaldehyde are used as polymer binders for manufacturing composite materials gradually replacing commercial synthetic resins. The paper presents results of the investigation related to developing a resource-saving technology for the recovery of phenol and formaldehyde from industrial phenolic wastewater by obtaining composite construction material and sodium phenolate. Sawdust and wastes from textolite manufacturing and processing were used as fillers and modifiers in a composite mixture. The presented technological process has been developed on the base of recycling using combined technologies through inter-industrial collaboration. This approach makes it possible to obtain high-quality recycled products from technogenic raw materials (degree of phenol conversion was 0.995) and to carry out complete dephenolization of the wastewater (residual phenol concentration was 2⋅10−2 mg/l), which can be used in the wastewater reuse system for the main chemical manufacturing.