Abstract
Industrial wastewaters may contain toxic or highly inhibitive compounds, which makes the measurement of biological oxygen demand (BOD) challenging. Due to the high concentration of organic compounds within them, industrial wastewater samples must be diluted to perform BOD measurements. This study focused on determining the reliability of wastewater BOD measurement using two different types of industrial wastewater, namely pharmaceutical wastewater containing a total organic carbon (TOC) value of 34,000 mg(C)/L and industrial paper manufacturing wastewater containing a corresponding TOC value of 30 mg(C)/L. Both manometric respirometry and the closed-bottle method were used in the study, and the results were compared. It was found that the dilution wastewaters containing inhibitive compounds affected BOD values, which increased due to the decreased inhibiting effect of wastewater pollutants. Therefore, the correct BOD for effluents should be measured from undiluted samples, while the diluted value is appropriate for determining the maximum value for biodegradable organic material in the effluent. The accuracy of the results from the blank samples was also examined, and it was found that the readings of these were different to those from the samples. Therefore, the blank value that must be subtracted may differ depending on the sample.
Highlights
Biodegradability is an important indicator when assessing the environmental friendliness of pollutants in wastewater that refers to the activity of degradation by bacteria and microorganisms
This means that the biological oxygen demand (BOD) of the raw water was low or zero, since the bacteria could not decompose the sample when they could not function in the solution
We examined the biodegradability of wastewaters containing inhibitive pollutants and the differences between the BOD values of undiluted and diluted wastewaters
Summary
Biodegradability is an important indicator when assessing the environmental friendliness of pollutants in wastewater that refers to the activity of degradation by bacteria and microorganisms. Biodegradation is nature’s own treatment method for mineralizing organic compounds that are widely used in wastewater treatment. It is a cheap and effective means of doing so, as the bacteria degrade the pollutants [1,2]. The samples examined in this study were inhibitory industrial wastewaters [3,4]. This means that the BOD of the raw water was low or zero, since the bacteria could not decompose the sample when they could not function in the solution
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
