Treatment of tannery wastewater for reuse by physico-chemical processes and a membrane bioreactor

Treatment of wastewater from a tannery in Greater Ho Chi Minh City (Vietnam) was investigated on a pilot scale. After pre-treatment by the tannery that included batch-coagulation and sedimentation, the wastewater was treated by dissolved air flotation, a membrane bioreactor (MBR) and granular activated carbon (GAC) for polishing the MBR effluent. The average removal efficiency for organic substances in the MBR was 81% while total nitrogen could only be removed by 36%. The performance of the GAC column could be successfully predicted using adsorption parameters determined in laboratory experiments. A larger proportion of the organics in the MBR effluent was only weakly adsorbable, therefore the usable carbon capacity was limited as confirmed by the modelling approach. The results were used to outline the size of a technical plant with a volumetric loading rate of 3 kg COD/(m*d) for the MBR and a specific carbon demand of about 1.8 kg/m. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY-NC-ND 4.0), which permits copying and redistribution for non-commercial purposes with no derivatives, provided the original work is properly cited (http://creativecommons.org/ licenses/by-nc-nd/4.0/). doi: 10.2166/wrd.2016.036 J. Fettig (corresponding author) V. Pick M. Oldenburg University of Applied Sciences Ostwestfalen-Lippe, Hoexter 37671, Germany E-mail: [email protected] N. V. Phuoc Institute for Environment and Resources, National University, 142 To Hien Thanh Street, District 10, Ho Chi Minh City, Vietnam