Removal of aniline, cyanides and diphenylguanidine from industrial wastewater using a full-scale moving bed biofilm reactor

• A full-scale moving bed biofilm reactor (MBBR) was operated for 5 years.
• MBBR was fed with wastewater containing cyanides, aniline and very high salinity.
• Mean cyanide removal efficiency ranged from 75% to 99%.
• Aniline removal efficiency reached more than 85%.
• The MBBR was capable to fulfil the requirements of Czech Water and Waste Acts.

Treatment of industrial wastewaters is usually difficult due to large variations in their composition, high organic matter content and presence of poorly biodegradable compounds. This paper describes operational experience with the first full-scale application of a moving bed biofilm reactor (MBBR) in the Czech Republic. The MBBR treats industrial wastewater from the Lučební závody Draslovka a.s. (Kolín) chemical plant in the Czech Republic, and particularly that from production of diphenylguanidine. The wastewater is characterised by a high content of cyanides and aniline, very high salinity, diphenylguanidine and phenylurea residues, and considerable fluctuations in concentrations as well as temperature during the year.Long-term (5-years) MBBR operation has demonstrated that, following initial stabilisation and implementation of additional pretreatment, the system is capable of treating such hardly biodegradable industrial wastewater with high removal efficiency, with mean cyanide removal efficiency ranging from 75% to 99%. Aniline removal efficiency also reached more than 85%, while diphenylguanidine, phenylurea and N,N-diphenylurea removal was almost quantitative.