WATER QUALITY: CONTAMINATION AND PROTECTION

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WATER QUALITY CONTAMINATION AND PROTECTION
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1. Water Quality

• Microbiological Quality
• Presence of organisms that cannot be seen by
  the naked eye faecal and total coliforms
• Physical Quality
• Affecting taste, odour and appearance. pH,
  Turbidity etc.
• Chemical Quality
• Nature and concentration of dissolved
  substances. E.g salts, organics, etc. Most of
  these are essential, but in high quantities may
  cause problems.

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2. Common Water Quality Problems Surface Water

• Faecal Pollution
• High faecal and total coliform counts near
  dense human settlements
• Colour and Stability
• Due to organic acids
• Salt Concentrations (TDS)
• High sulphate and chloride concentrations.
  Corrosive and distinctly salty

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2. Common Water Quality Problems Surface Water

• Eutrophication
• High nutrient concentration (nitrogen,
  phosphate) and high algal concentrations.

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3. Common Water Quality Problems Groundwater

• Salinity
• Occurs where the predominant geological
  formations are sedimentary rocks of marine
  origin. Eg. The Karoo
• Fluoride
• Especially in the coal bearing regions
  (central and western parts of the country)
• Sulphate and Chloride
• Especially water with high TDS

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3. Common Water Quality Problems Groundwater

• Calcium and Magnessium
• Especially in dolomitic areas
• Iron and Manganese
• While they commonly occur in high
  concentrations in groundwater, treatment is easy

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4. Water Pollution

• Water Pollution occurs when water is rendered
  less fit for use as a result of human activities
• Waste generated by human activity enters the
  water environment.
• Human Activities Waste Streams
• -Intensive Irrigation/Agri. -Sewage
  Waste (Domestic/Indust.)
• -Mining activities
  -Gray water
• -Industrial activity
  -Stormwater
• -Dense human settlements -Solid waste

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5. Protection of Water

• Everyone needs to be involved
• National Government must provide a framework
  (policy) and legislation for protecting our water
  sources
• Provincial and local level management measures
  and actions must be developed for giving effect
  to the national water quality management
  framework and legislation
• Business Owners
• Industry
• Mines
• Farmers
• Interest Groups
• General Public

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6. Water Treatment Chlorination

• Water-borne diseases are spread by pathogens
  (disease-causing micro-organisms such as
  bacteria and viruses) in water
• Pathogenic micro-organisms enter water supplies
  as result of pollution by human and animal
  wastes.
• A lot of bacteria and viruses will remain after
  the First Barrier and Second Barrier treatment
• The final barrier is disinfection destruction
  of the harmful micro-organism though the use of
  a chemical agent.

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7. Water Treatment Chlorination

• Types of possible disinfectants
• Chlorine, Ozone, Chlorine Dioxide, Calcium
  hypochlorite (HTH), Sodium hypochlorite (bleach)
  and monochloramine
• Chlorine is by far the most effective, easy to
  control, cost effective and used in over 98 of
  water treatment works worldwide.
• Side effects and other issues such formation
  THMs have been highlighted they are all minor
  and negligible as compared to the benefits of
  chlorinating water. Eg. Cholera epidemic.

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5. Water Treatment Fluoridation

• Water fluoridation involves addition of
  predetermined amounts of a fluoride-containing
  chemical to the water during a water treatment
  process in order to increase the fluoride
  concentration to a specific level.
• The WRC is currently involved in research to
  parameters and control that determines safe and
  effective fluoridation of water
• On the other side of the coin is defluoridation
  where there is also ongoing research to reduce
  fluoride from waters with high fluoride
  concentration, though the use of modified locally
  occurring

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7. Relevant Research

• Five main fields of research addressed water
  quality and related problems
• Over 200 projects have been carried out
• Over R150 million has been spent
• Over 30 patents have been taken
• Over 200 reports, workshops, training session.
• At least 5 centres of expertise
• Over R40 million invested in on going projects
• All major water treatment plants are using one or
  more processes or technology developed through
  WRC funding

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RESEARCH OUTPUTS

• Sewage sludge guidelines and addendum to promote
  safe use of sludge for crop production
• Compilation of a guide to assess the magnitude of
  non-point source pollution
• With DWAF Development of methodology to
  implement Waste Discharge Charges (Polluter pays
  principle)
• Models to simulate effect of acid mine water on
  the quality of Witbank Dam
• Design of soil covers for coal discard dumps that
  exclude oxygen formation of acid mine drainage
• Use saline mine water to irrigate crops and
  remove gypsum
• Reduced cost to neutralize acid mine water using
  cheaper agents.

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RESEARCH OUTPUTS

• Aerobic Digestion (Low cost sanitation) Almost
  all waste water treatment plants in SA use this
  technology
• Biosure Process Treatment of high sulphate
  waters (acid mine water)
• Environmental technology and Integrated waste
  water beneficiation treatment of high volume
  saline waters
• Petro Process
• Membrane Technologies