It depends on the own characteristics of the specific wastewater.
COD values are generally higher than BOD, however, there is no real ratio. It depends on the treatment process i.e if the same process is used all the time under the same conditions. Other factors can affect both factors such as composition of the waste being treated.
Polytechnical University of Valencia
Prince of Songkla University
Indian Institute of Technology Guwahati
Leibniz Universität Hannover
Sultan Qaboos University
Université Hassan II Casablanca
University of Akron
Universiti Tun Hussein Onn Malaysia
Kharkiv National Academy of Municipal Economy