In current study, the principle and working of physiochemical and biological oxygen demand plant, of SP paper board mill, Barasat is presented.  Here mainly the study is concerned with the treatment of waste water analysis and by products, plant effluent and it’s recycling. The various physiochemical and biological treatment methods are also discussed in the report. Nevertheless, the emphasis is more towards the removal of TSS and oil and grease maintaining with in permissible limits of BOD, COD, pH etc. Finally the various standard procedures for determination of concentration of the contaminants and standard concentration of contaminants are comparing with the permissible norms. Here I have also perform the bacteriological study from the waste water sample and finally I also reported about the economically benefit product of the industry and give our attention for making zero level discharge in final outlet during treatment operation.