HMGA Water Project
  • Home
  • Project Overview
    • Project Description
    • Project Team
    • Collaborative Projects
    • FAQ
  • Publications
    • Blog
    • Factsheets
    • News Articles
  • Events
  • Gallery
  • Dedirting
  • Contact

Filter Bags Demonstration Site

1/26/2015

0 Comments

 
One technology under examination by the project is filter bags. They are made out of fabric and are available with different sized pores. Wastewater is pumped into the bag and the sediment is caught by the fabric while treated water is strained out. The water is then collected and continues through further treatment if necessary.
Picture
Figure 1: A filter bag on the collection table above a tank with a pipe to return treated water to a settling pond (left) and an expanding bag (right)
In order to test the system, a pump was placed at the inlet of a settling pond to send a sample of carrot washwater to a scaled-down filter bag (Figure 1). The washwater was pumped in and clearer water flowed out of the bag. The bag was successful in straining out both pieces of carrots and soil particles (Figure 2).
Picture
Figure 2: Inflow of vegetable washwater at the top and outflow from the filter bag at the bottom (left) and solids filtered by the bag (right)
There were two issues with the system identified by this test. First, the pump sending the water to the bag was plugged several times by large chunks of carrots. Those larger pieces would either have to be removed earlier or chopped prior to the filter bag. Second, the bag clogged due to the colloids in the water and ruptured at the seam when the water had nowhere to exit and pressure built within the bag. The addition of coagulants would reduce this problem by clumping the colloids prior to the bag.

The filter bag system was certainly successful at removing solids from the washwater and since they are collected in a bag, the discarding of the waste is straightforward. Unlike settling ponds, which have to be dug out on a regular basis, the bag can simply be replaced with a new one when full.

A larger sized filter bag will be tested in the future to further review the benefits and challenges this system presents.
0 Comments

Defining Dissolved Oxygen

1/5/2015

2 Comments

 
Dissolved oxygen (DO) is the amount of oxygen in water. The main sources of DO in water are the atmosphere and aquatic vegetation. The oxygen is then lost through oxidation of sediment, by respiration of aquatic organisms, and oxidation of organic matter. The input and consumption of DO in an aquatic system are influenced by temperature, water depth and water movement. 
Picture
Figure 1: Dissolved Oxygen cycle in freshwater [Source: http://www.nanoos.org/education/learning_tools/hypoxia/oxygen_underwater.php]
If the amount of oxygen consumed exceeds the input amount, the oxygen becomes depleted in the system. If DO levels become too low then stress is put on aquatic systems, and most aquatic species cannot survive without oxygen. The water quality guidelines for the protection of aquatic life are found in Table 1, and are dependent on water temperature and life stage. Adult fish have the ability to survive at lower values of DO depending on the species and water temperature, but the limited oxygen will negate their abilities to reproduce along with the survival of juvenile fish. If an aquatic system begins to have lower DO levels than in the past, this could change the biodiversity of the ecosystem as this will attract species which have tolerances to lower DO, or anaerobic organisms (which don’t need oxygen for survival) while ones with less tolerance will leave. 
Picture
Waste water from washing fruits and vegetables tends to have low DO levels. It is important to try and increase the DO in this water through different systems such as settling ponds with aerators and other technologies to reduce the environmental impacts. The Lake Simcoe Protection Plan indicated a goal of 7 mg/L DO in deep water in 2008; in 2012 the DO levels had improved over the values from 2008 but were not yet at the goal.

References
  • Canadian Council of Ministers of the Environment. 1999. Canadian water quality guidelines for the protection of aquatic life: Dissolved oxygen (freshwater). In: Canadian environmental quality guidelines, 1999, Canadian Council of Ministers of the Environment, Winnipeg.
  • Government of Ontario. 2013. Minister’s Annual Report on Lake Simcoe 2011-2012. Queen’s Printer of Ontario. Toronto, Ontario
  • Oram, B. 2014. Dissolved Oxygen in Water. Water Research Watershed Center. http://www.water-research.net/index.php/dissovled-oxygen-in-water
2 Comments

    Project Updates

    Find articles on project-related topics here

    Archives

    December 2016
    October 2016
    September 2016
    July 2016
    June 2016
    May 2016
    April 2016
    March 2016
    February 2016
    January 2016
    December 2015
    November 2015
    October 2015
    September 2015
    August 2015
    July 2015
    June 2015
    May 2015
    April 2015
    March 2015
    February 2015
    January 2015
    December 2014
    November 2014
    October 2014
    September 2014

    Topics

    All
    Aerators
    Coagulation & Flocculation
    Deionization
    Discharge Characterization
    Drum Filter
    Filter Bags
    General Information
    Hydrocyclone
    Lake Simcoe
    Lesson Learned
    Muck
    Nottawasaga Valley
    Pre Treatment
    Pre-Treatment
    Sampling
    Settling Ponds/Tanks
    South-Eastern Georgian Bay
    System Evaluation
    Treatment Technologies
    Ultrafiltration
    Washing Process
    Water Quality Parameters
    Watershed

    RSS Feed

    Article Titles

    Introduction to
      Watersheds

    Lake Simcoe Watershed
    Nottawasaga Valley
      Watershed
    South-Eastern Georgian
      Bay Watershed
    Water, Water,
      Everywhere?
    The Trouble with Muck:
      Size
    Lesson Learned: Bottom-
      up Aerator to Treat
      Washwater in Settling
      Tanks
    Phosphorus, the
      Environment, and
      Farming
    Nitrogen’s Impact on Air,
      Land, and Water
    Water-borne Pathogens
      and Food Safety
    Defining Dissolved
      Oxygen
    Filter Bags
      Demonstration Site
    Organic Matter
      Breakdown &
      Biochemical Oxygen
      Demand
    Dealing with Cloudy
      Water
    Hydrocyclone
      Demonstration Test
    What IS Muck?
    Demystifying Oxidation-
      Reduction Potential
    News Release
      "Technology
      Investigation: Filter
      Bags"
    Drum Filter
      Demonstration Site
    Decomposing With(out)
      Oxygen
    Flow monitoring
    Lesson Learned: Drum
      Filter Optimization
    Polders & the Holland
      Marsh
    Vegetable Washing
      Process
    ​Dry Soil Removal
    Ultrafiltration &
      Deionization
      Demonstration Site
    News Release
      "Technology
      Investigation:
      Ultrafiltration &
      Capacitive Deionization"
    Progressive Passive
      Filtration
    ​Dissolved Air Flotation
    Clarifying the Solid
      Removal Process
    Factsheet Reading Order
    News Release:
      "Technology
      Investigation:
      Coagulation &
      Flocculation"
    Self-Indexing Filter
    Monitoring Discharge
    ​  Flows
    Settling Soil
    Mass Loading
      Calculations
    Lesson Learned:
      Technology Selection
    Electrocoagulation
    Auto-Samplers
Powered by Create your own unique website with customizable templates.