Grantee Research Project Results
Final Report: Novel Ceramic Membrane Bioreactor for Low-Flow Systems
EPA Contract Number: EPD04031Title: Novel Ceramic Membrane Bioreactor for Low-Flow Systems
Investigators: Bishop, Bruce A.
Small Business: CeraMem Corporation
EPA Contact: Richards, April
Phase: I
Project Period: March 1, 2004 through August 31, 2004
Project Amount: $70,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2004) RFA Text | Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , SBIR - Water and Wastewater , Small Business Innovation Research (SBIR)
Description:
The goal of this research project was to demonstrate the technical feasibility of using CeraMem Corporation’s honeycomb-based ceramic membrane modules in membrane bioreactor (MBR) systems for the treatment of sanitary wastewater in low-flow systems (i.e., less than 50,000 gallons per day). Small MBR systems, appropriate for use in small communities, apartment complexes, or residential developments, need a robust process so that limited maintenance will be required and, when maintenance is necessary, personnel with limited training will be able to maintain the systems. Ceramic membranes are more likely to fit this need than polymeric membranes because of perceived longer lifetimes, less likelihood for membrane mechanical failure, and the ability to be cleaned aggressively.
In Phase I, ceramic membranes were fabricated and tested in membrane systems coupled to bioreactors processing actual sanitary wastewater. The ceramic membranes were fabricated as pilot-scale elements with a diameter of 67 mm, a length of 864 mm, and a square passageway size of 5 mm. Each element contained about 1 m2 of membrane area. The fabricated membrane types were a 0.1-µm alumina microfiltration membrane and a 10-nm titania ultrafiltration membrane. Membrane elements and housings were supplied to Cranfield University in the United Kingdom, where a system was constructed and tested (with nonproject funds). Zenon Environmental in Canada conducted a second set of tests that were not yet completed at the time of this report. Zenon has been funding the activity at their site. CeraMem supplied both the membranes and an automated system to Zenon, to which a bioreactor operating on sanitary wastewater was interfaced. Preliminary system design and costing also was conducted.
Summary/Accomplishments (Outputs/Outcomes):
There were four main results of Phase I. First, CeraMem successfully fabricated and then coated 5-mm passageway membrane supports. Membrane coating development started with membrane slip formulations and coating processes developed to coat 2-mm passageways. These were modified for the 5-mm passageway supports, and both a microfiltration (MF) and an ultrafiltration membrane were fabricated. Examples of a monolith membrane support and a membrane element are shown in Figure 1.
Figure 1. SiC monolith (right) and membrane element (left).
Second, CeraMem successfully designed and constructed a membrane test system for operation at Zenon and assisted Cranfield in the design of their test system. Each of the test systems was designed to operate with one pilot-scale membrane module in airlift or pumped airlift mode.
Third, test data from Cranfield showed that a flux in excess of 60 lmh could be maintained well in excess of 40 hours (see Figure 2).
Figure 2. Cranfield University MBR test data. Data shown in blue represent the mixed liquor suspended solid concentration, and those shown in red represent process flux.
These data were obtained using a 0.1-µm alumina MF membrane element. The liquid crossflow velocity was 0.94 m/s and the airflow velocity was 0.89 m/s during the test. The bioreactor hydraulic residence time was between 5 and 6 hours, and no sludge was wasted during testing. This caused the mixed liquor suspended solid concentration to increase slowly until an equipment failure caused it to drop at the end of the testing period. This flux result, combined with initial results from Zenon, indicated that the energy consumption for the process was reasonable. Fourth, initial estimates of membrane and membrane system costs appear to be within reason for small communities. Initial estimates were $20,000 for the membranes and between $200,000 and $600,000 for uninstalled systems.
Conclusions:
The technical feasibility of using monolith honeycomb-supported ceramic membranes in an MBR process has been shown. Process flux in excess of that typically seen for polymeric membranes has been demonstrated under realistic operating conditions. This flux will compensate for the higher costs of ceramic membranes as compared to polymeric membranes. Additional product, process, and manufacturing developments are required to determine if CeraMem’s ceramic membranes are commercially viable in the marketplace.
The technology developed and evaluated in Phase I will be applicable to treating a variety of wastewaters and industrial feedstreams. The mixed liquor from a bioreactor treating wastewater from industrial, commercial, or municipal sources can be filtered using the Phase I technology. This applies to anaerobic as well as aerobic systems. The best commercial range of system flows for this membrane technology has not yet been determined. Also, other applications in fine chemicals and/or pharmaceuticals production may be appropriate for this technology.
Journal Articles:
No journal articles submitted with this report: View all 1 publications for this projectSupplemental Keywords:
membrane bioreactor, MBR, wastewater treatment, ceramic membrane, microfiltration, ultrafiltration, membrane system, bioreactors, membrane element, alumina, SiC, monolith membrane support, SBIR,, Scientific Discipline, Air, Water, TREATMENT/CONTROL, Sustainable Industry/Business, Chemical Engineering, cleaner production/pollution prevention, Wastewater, Environmental Chemistry, Chemistry, Engineering, Engineering, Chemistry, & Physics, Environmental Engineering, Water Pollution Control, ceramic membrane, wastewater treatment, membrane bioreactor, ceramic membranesThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.