SWANA Chapter Conference 2008

West Edmonton Landfill

Leachate Treatment Plant

By Steve Johnson M.Eng, P.Eng

Introduction

• Leachate Management Options

• West Edmonton Leachate treatment process

• Treatment Plant Commissioning/Status

• Lessons learned

Leachate Management Options

• Dispose to municipal wastewater treatment plant

• Dispose to deepwell

• recirculate

• Onsite treatment

• Mechanical plant

• Evaporator

• wetlands

• Do nothing

Leachate treatment process

• Phases of leachate management since 1974• Do nothing

• dust control

• Recirculation/offsite deep well disposal

• Develop leachate treatment plant

Leachate treatment process

In 2006 evaluate leachate treatment options• Consultants

• Leachate quantity estimate

• Technology evaluation

• Disposal options

• Haul to deepwell – unreliable

• Recirculation no longer approved by AENV

• City of Edmonton sewer bylaw

• To reduce liability best to treat on-site

Treatment Plant Commissioning/Status

• New Logic Research Inc. http://www.vsep.com/

• Vibratory Sheer Enhanced Processing technology

• Leachate pilot plant test conducted in US

• Pilot test basis• 5 day trial

• Several membranes investigated for pressures, short term line out, concentration, cleaning

Treatment Plant Commissioning/Status

                                                        

Treatment Plant Commissioning/Status

Treatment Plant Commissioning/Status

Treatment Plant Commissioning/Status

• Plant set up during fall of 2007• 4 Feed tanks• 3 mix tanks• 2 concentrate tanks• 2 permeate tanks• Hot water tank• VSEP skid• Pumps, valves, hoses

• Treatment R&D trials for approximately 6 months• Leachate mixes as quality varies throughout landfill• Single pass and percent recovery modes• pH, anti-scaling, and process temperature

Treatment Plant Commissioning/Status

• Quality targets• Permeate - City of Edmonton sanitary sewer bylaw

• Permeate - Agriculture irrigation guideline

• Concentrate - Non-haz waste – AB User’s Guide

• Operational finding with current leachate mix• Single pass mode

• 4 to 4.5 m3/hr depending on cleaning frequency

• Permeate to concentrate ratio of 80:20

Treatment Plant Commissioning/Status

• Operational finding with current leachate mix (cont.)• Percent recovery mode

• Membrane efficiency decreases at a faster rate then single pass

• Concentrate quality worse then single pass

Current Operation• Six hours per day five days per week

• Two hours per day for cleaning

Treatment Plant Commissioning/Status

• Future developments• R&D to trial temperature adjustment (heat exchanger), pH

adjustment, and anti-scaling to determine affect on membrane performance

• Plan to add another shift in route to automate plant for 24 hr/d operation

• To include additional feed, blend, and concentrate tanks

• Treatment target of 6 to 7 m3/hr

Lessons learned

• New computer hard drives can crash (have a back-up)• There is always one or more parameters where mass balance

doesn’t apply to the laboratory results between feed, concentrate and permeate

• New Logic Research has good customer service and documentation (process binders, operations binders)

• Plant design to include upgraded breaker and checkvalve in cleaning loop

• Laboratory response time is inadequate for R&D• Limited odour experienced • R&D takes much longer than anticipated

Questions