2013 Technical Session 20 - Emerging Technologies

Tuesday, April 23, 1:55 - 5:00 pm, Shuswap Room


Moderator: Deborah Roberts, UBC

 

20.1 Bacteriophage-based Biological Control of Acid Mine Drainage

20.2 Examining the Potential of Integrating Wastewater Nutrient Removal and Algal Carbon Capture

20.3 Ground Freezing to Stabilize and Allow Excavation

20.4 Ground Freezing: The Way of the Future for Utility Excavation Stabilization?

20.5 Using MESH Radio Networks to Enhance Data Reliability & Redundancy of a SCADA System


Emerging technologies | 1:55 pm - 2:25 pm
20.1 Bacteriophage-based Biological Control of Acid Mine Drainage
Presenter: Yeyuan (Roger) Xiao, Ph.D., P.Eng., University of British Columbia, Kelowna, BC
Additional Contributors: Deborah J. Roberts, Ph.D., Eng.L., University of British Columbia, Kelowna, BC



Acid mine drainage (AMD) is the largest environmental liability facing the Canadian mining industry. Lime neutralization is the most widely-used practice to treat AMD. However, this process generates large volumes of potentially hazardous solid waste. High maintenance costs and demanding environmental standards have kept engineers and researchers searching for more sustainable measures to tackle AMD. Sulfur-oxidizing microorganisms (SOM) are well known as  significant contributors to AMD. In this research a novel approach using bacteriophage (phage), a virus infecting and killing specific bacteria, was used to prevent or stop the growth of SOM and is under examination to prevent the occurrence of AMD or remediate ongoing AMD. Three 3-litre batch reactors, using pyrite rich oil sands tailings as the inocula, were used in the laboratory to enrich SOM at three different pH (7, 4.5 and 2.5). Pure strains of SOM were isolated from the reactors and used to grow phage as the hosts. The pure cultures were mixed with the liquor suspensions from the original reactors and incubated at 30°C for seven days to enrich phage. The enrichment suspensions were centrifuged and filtered through 0.2 µm filter, which resulted in phage suspensions in the filtrate. The phage infectivity was checked using the traditional plaque assay. A phage cocktail was created containing different phages and applied to sub-cultures of the reactors. The results showed that the phage cocktail could effectively stop the growth of SOM, which suggests that phage-based approach might be a promising measure to control AMD in situ.

Presentation PDF
 


Emerging technologies | 2:30 pm - 3:00 pm
20.2 Examining the Potential of Integrating Wastewater Nutrient Removal and Algal Carbon Capture
Presenter: Genevieve Tokgoz, P.Eng., M.Eng., LEED AP, CEM, Metro Vancouver, Burnaby, BC
Additional Contributors: Dr. Patrick McGinn, PhD, National Research Council, Halifax, NS; Dr. Kyoung Park, PhD, National Research Council, Halifax, NS



Metro Vancouver is continually seeking opportunities to implement integrated resource recovery opportunities as part of its operations and is exploring the future possibility of co-locating a facility for wastewater treatment and microalgae cultivation. Treated municipal wastewater effluent is a readily available source of nitrogen and phosphorus, nutrients needed for cultivating microalgae for the production of bioenergy and other bioproducts. As a first step, the National Research Council of Canada and Metro Vancouver collaborated to test the suitability of effluent from the Annacis Island Wastewater Treatment Plant as a growing media for microalgae. Samples of Annacis Island secondary effluent and centrate from solids dewatering were evaluated at National Research Council facilities in Halifax as nutrient sources for two photosynthetic green algae. Scenedesmus sp. AMDD and Chlorella sorokiniana were grown in duplicate, 250 mL batch-flasks in controlled environment chambers at 22°C. The concentrations of dissolved NH3-N and PO43--P averaged 14 and 0.82 mg/L, respectively, in effluent and 1280 and 230 mg/L, respectively, in centrate samples. Carbon dioxide was added to the air stream to a final concentration of 2% (v/v). The effluent samples supported specific growth rates of approximately 1.0 d-1 in both species and average biomass yields of 0.59 g/L and 0.41 g/L in Scenedesmus and Chlorella, respectively. Blending the effluent with up to 5% centrate enhanced biomass yields significantly in both species and resulted in 100% ammonia and phosphate removal from the wastewater through algal growth. Given the successful bench-scale cultivation of the selected microalgae species, Metro Vancouver is seeking collaborators to pilot technologies at its recently established Sustainability Academy – Annacis Wastewater Centre as the next step.

Presentation PDF
 


Emerging technologies | 3:05 pm - 3:35 pm
20.3 Ground Freezing to Stabilize and Allow Excavation
Presenter: David O'Sullivan, PW Trenchless Construction Inc, Surrey, BC
Additional Contributors: Ian Ross, Canadian Dewatering



The discharge of ground water into storm sewer systems with a high iron content is not allowed. Rather than try to treat the water and remove the iron we completed a project where we froze the ground to stabilize it. We were also very restricted because of the close proximity of a 30m block building that would have failed had we lowered the water table. We highlight the lessons learned in using ground freezing and its feasibility for future work.
 
Presentation PDF


Emerging technologies | 3:55 pm - 4:25 pm
20.4 Ground Freezing: The Way of the Future for Utility Excavation Stabilization?
Presenter: Michael Schwanke, EIT, Delcan Corporation, Burnaby, BC
Additional Contributors: Jim Young, P. Eng. City of Richmond, BC



As part of its annual capital program, the City of Richmond identifies and replaces sections of sanitary sewer that are under capacity or are nearing the end of their service life. Replacement of the infrastructure prior to failure reduces maintenance and repair costs and provides an opportunity for upsizing to meet future demands from development. The 100m long section of sanitary sewer main extending across the frontage of 9500 Van Horne Way was recommended for replacement through two processes:
1. The 2041 Official Community Plan modelling called for an increase in size to 450mm diameter.
2. Construction on the adjacent section of main and subsequent CCTV inspection revealed the deteriorating condition of the fibre reinforced plastic (FRP) main.
Replacement of the FRP ensured continued service to commercial, industrial and residential customers in the area. The characteristics of this site made this project particularly challenging. Being near the pump station, the existing 350mm main was 4.5m deep. With a high water table, high iron content in the ground water and weak soils, consideration was given to typical mainline construction methods as well as some emerging trenchless technologies. In areas with high water tables, typical mainline construction methods consist of open cut excavations combined with well pointing. For this project open cut construction was an expensive option; the expected high flows from the well pointing would have likely exceed the capacity of the receiving system and treatment to meet the municipal and provincial water quality standards would have been cost prohibitive. Possible settlements from dewatering could have also jeopardized nearby structures. Pipe bursting was proposed as a viable alternative for construction. This trenchless technology significantly reduced the project’s cost and footprint while addressing many of the problems of traditional open cut construction. However, the entry and exit pits needed to be stabilized and dewatered, leading to expensive groundwater treatment prior to discharge. To address the issue of dewatering an emerging technology was employed to stabilize the two excavations: ground freezing. As its name suggests, the ground was artificially frozen using a closed loop system that circulated a cooled brine solution to extract heat from the ground resulting in localized freezing. Being a closed system, water was not extracted from the ground and water treatment was not be required resulting in a cost savings. Some issues that were considered included soil and ground water conditions, localized ground heaving and settlement within the area of freezing and the effects of differential settlement on the pipe at the interface between the frozen and unfrozen ground during the thawing period.
 
Presentation PDF


Emerging technologies | 4:30 pm - 5:00 pm
20.5 Using MESH Radio Networks to Enhance Data Reliability & Redundancy of a SCADA System
Presenter: Tom Dunn, Senior Tech, Opus DaytonKnight Consultants Ltd., North Vancouver, BC
Additional Contributors: Victor KL Wong, P.Eng, Opus DaytonKnight Consultants Ltd., North Vancouver, BC



This will be a discussion on utilizing MESH radio technics to enhance radio data reliability and redundancy of communications in a multiple application SCADA system. Low speed (less than 20 Kbps-Kilobit per second) data networks will process data messages with little or no delay, and generally most radio system sites utilize one radio path back to the Host computer. If the radio path is faulted as a result of equipment failure, then the data messages do not get through and a communications error message would be generated. Mesh radio technics allow multiple radio paths to be accessed to improve reliability of the data messaging. Higher speed applications can overwhelm the low speed communications channel and cause unreasonable delays in critical alarm data. Mesh systems utilize higher bandwidth spread spectrum technics to increase bandwidth for combined data messaging.

Presentation PDF



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