 | Water Reuse for Industrial Wastewater |
| Expanded Title: | This project investigated the application of the dual stage operations strategy in a pilot plant evaluation of a MBR
(dsMBR) for the on-site treatment and recovery (reuse) of industrial trade effluent. The goal of the study was to use
the MBR system as a pre-treatment for the reduction of the wastewater pollution load so that a downstream
reverse osmosis (RO) system can be incorporated to facilitate a zero liquid discharge strategy as well as effluent
reuse potential for the industrial partner.
A textile manufacturer located in the Western Cape was chosen as one of the industrial partners for the on-site
evaluation of the pilot plant. A 5-10m3/day MBR pilot plant incorporating sidestream Airlift™ membrane modules
was designed and was operated on-site from March to December 2010. The design of the dsMBR process was
geared towards optimal microbial community enrichment and was based on a pre-denitrification configuration
coupled with enhanced biological phosphate removal (EBPR) (anaerobic-anoxic-aerobic with recycle loops). The
anaerobic-anoxic-aerobic process was designed to incorporate two primary functionalities: influent azo dye
cleavage in a reducing environment followed by oxidation of the resultant aromatic amines; and biological nutrient
removal through enrichment of associated microbial consortia using nitrification, denitrification, and phosphate
removal processes. To achieve this, the preliminary data analysis was used to identify critical scale-up criteria. In
terms of overall results, COD removal fluctuated considerably during the 3-month start-up stage (~100 days),
thereafter, an average of 90-95% removal was achieved under optimised conditions. When compared to the South
African (SA) government discharge standard for COD (5000mg/L), the COD value for the treated textile effluent (20
mg/L) was well within this standard.
A paper and pulp industry located in the Western Cape was also chosen as an industrial partner for the evaluation
of a pilot-scale MBR plant for the treatment of paper mill effluent. A 45- 65 L/day MBR pilot plant incorporating
ceramic membranes in an external modular configuration (similar to the sidestream Airlift™ membrane modules)
was designed and was operated in a laboratory from June to December 2010. The design of the dual-stage
membrane bioreactor was based on a pretreatment high rate anaerobic system (EGSB) coupled with a posttreatment
denitrification/nitrifation configuration (anaerobic-anoxic-aerobic with recycle loops). The high rate
anaerobic process was designed to reduce influent COD in an attempt to reduce the need for high volume dosing.
The anoxic-aerobic processes were designed to incorporate two primary functionalities: further reduction of COD
concentration; and biological nutrient removal through enrichment of associated microbial consortia using
nitrification and denitrification processes. In terms of effluent COD reduction efficiency, the anaerobic pretreatment
stage gave an average of 70% COD removal while the MLE-MBR stage increase the total COD removal
to 97%. |
| Date Published: | 01/05/2013 |
| Document Type: | Research Report |
| Document Subjects: | Wastewater Management - Industrial |
| Document Format: | Report |
| Document File Type: | pdf |
| Research Report Type: | Technical |
| WRC Report No: | TT 556/12 |
| ISBN No: | 978-1-4312-0411-3 |
| Authors: | Edwards W; Sheldon MS; Zeelie PJ; De Jager D; Dekker LG; Bezuidenhout CC |
| Project No: | K5/1900 |
| Originator: | WRC |
| Organizations: | Atl-Hydro; Cape Peninsula University of Technology; Dekker Envirotech; North West University; Falke Eurosocks |
| Document Size: | 2 870 KB |
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