50    APPLICATION OF ANAEROBIC RESPIROMETERS
FOR TREATABILITY ASSESSMENT OF INDUSTRIAL
WASTEWATERS
Nadim Reza Khandaker, Environmental Engineer
ADI International Incorporated
Fredericton NB
Canada E3B 4YZ
INTRODUCTION
Before substantial time and money is spent in carrying out pilot scale or actual site work on a
candidate wastewater, it is important to determine the potential for anaerobic biodegradation of
the subject wastewater. Anaerobic respirometer can be used as a powerful tool to determine the
anaerobic biodegradability of industrial wastewaters. The objective of this chapter is to report on
case studies carried out by the author using anaerobic respirometer to determine the anaerobic
treatability of industrial wastewaters. The treatability assessment was based on the anaerobic
treatability screening protocol developed by Young.1 The treatability parameters investigated
were the rate and extent of degradation, toxicity, and culture acclimation.
TREATABILITY SCREENING PROTOCOL
The screening protocol used in this study was based on the treatability assessment protocol developed by Young1 and reported at length in an earlier publication by Young and Khandaker.2
The treatability test program consisted of two test phases. Phase I consist of batch serum bottle
tests, while Phase II involves the use of semicontinuous bench scale reactors. Master Culture Reactors (MCRs) were used to provide cultures having identifiable and repeatable characteristics so
that measurements made at different times and with different sets of tests would have a common
microbial and biochemical basis.
Master Culture Reactors
The Master Culture Reactors used in this study received ethanol at a loading rate of 1 g
COD/L-d augmented with nutrient minerals and buffer as substrate. The reactors were operated
at a continuous batch mode at the temperature of 35°C. The hydraulic and solids retention time
of the MCRs were fixed at 20 days. Details regarding MCR operation and feed formulation have
been reported by Young and Khandaker1-2-3 in earlier publications.
Analytical Procedures
Gas production from each test reactor was measured automatically by using an anaerobic
respirometer (Challenge ANR-200).3 The pH of the culture was measured by using a Fisher Scientific Accumet 425 Digital pH/ion meter.
Chemical Oxygen Demand (COD) and sulfate content were measured using Hach methods.4
Volatile suspended solids (VSS) were measured using glass fiber filters according to procedures
described by Standard Methods.5
Phase I Batch Tests
Batch serum bottle tests are the anaerobic counterparts to aerobic respirometer tests. Tests are
initiated by transferring active cultures from MCRs under anaerobic conditions to serum bottles.
51st Purdue Industrial Waste Conference Proceedings, 1996. Ann Arbor Press, Inc., Chelsea, Michigan 48118.
Printed in U.S.A.
483