Full-scale utilization of glycogen accumulating organisms in achieving
excess biological carbon removal during winery wastewater treatment
Bernadett Kiss
bkiss@mail.bme.hu
Supervisor: Andrea Jobbágy, associate professor
BUTE Applied Biotechnology and Food Sciences Department, Budapest, Hungary
Similarly to certain other food industrial processes, wine making operations
produce a special kind of wastewater with a relatively high carbon and low nutrient (N, P)
content. The nutrient deficiency can lead to the failure of the settling and in most cases
the effluent quality can not meet the declared environmental criteria [1]. In this case, the
conventional activated sludge treatment technologies can only be applied by using
supplementary nutrient (N and/or P) addition, which increases the operational costs, and
the efficiency is questionable due to the frequent and vigorous changes in the influent
quality.
The research group of BUTE Department of Agricultural Chemical
Technological developed a novel process using an anaerobic-aerobic reactor combination
by which the high C/N ratio can be easily treated, by the proliferation of glycogen
accumulating organisms (GAO) [2].
The research work has been focused on the Balatonboglár Winery’s wastewater
pretreatment plant, the first full-scale plant based on this technology. The purpose of the
study is to prove that this excess carbon removal technology works efficiently also in
full-scale, and to prove that it is a consequence of the growth of GAOs. Samples were
taken from September 2005 through August 2006 in 2 weeks periods from 12 sampling
points; while the main analytical parameters of the samples were measured in the
Department’s laboratory. There also were microscopic pictures taken of the native
biomass as well as of the samples stained with specific dyes.
In order to obtain further proof of the GAO’s presence supplementary batch tests
were carried out in which the anaerobic carbon consumption of the BB Winery’s biomass
was investigated in comparison with a biomass originated from a municipal wastewater
treatment plant.
In addition, direct proof for the presence of the GAO’s has been obtained in
cooperation with the National University of Singapore, Department of Environmental
Science and Engineering, through utilization of FISH and TRFLP microbiological
techniques on the samples from the 12-month full-scale sampling period.
It can be concluded, that the Balatonboglár winery wastewater pretreatment plant
can tolerate extremely high influent C/N ratios and low pH values, while its cleaning
efficiency is excellent. Results of the batch tests showed that the biomass of the BB
Winery’s wastewater plant consumes carbon source under anaerobic conditions, which
phenomenon can be related neither to the possibly occurring denirification, nor to the
metabolism of the phosphorous accumulating organisms (PAOs) that have metabolic
characteristics similar to the GAOs. This experience and the measured high intracellular
carbohydrate content of the biomass refer to the presence of GAOs. The microbiological
techniques proved the high abundance of GAOs in the Balatonboglár activated sludge,
which have basic role in the effective excess biological carbon removal.
CLSM (Confocal Laser Scanning Microscope) micrographs of FISH showing: gross fluorescently
labelled bacteria (green) and the tetrad forming GAOs typical in the BB Winery’s activated
sludge (red, but appears as yellow as a resultant of the red and the green stain combination)
References
[1] Jenkins, D., Richard, M. G. and Daigger, G.T. (1993). Manual on the Causes and
Control of Activated Sludge Bulking and Foaming. 2nd edition, Lewis, Ann Arbor.
[2] A. Jobbágy, B. Literáthy and G. Tardy (2002) Implementation of glycogen
accumulating bacteria in treating nutrient-deficient wastewater. Water Science and
Technology 46(1-2), 185-190