Part 5: Water Monitoring and Management Determining Water Quality Definition Impacts Possible Sources Cations, metal Unhealthy balance of cations can -Industrial discharge cations impair cell functioning. Most heavy -Mine drainage Positively charged ions metals are toxic to living things, with -Road runoff organisms higher in food chain being -Atmospheric pollution more vulnerable. Anions Nitrates and phosphates can cause -NO3- and PO43- come Negatively charged ions eutrophication. If DO is low, sulfates from ag. and urban can form H2S. If acidic, H2SO4 can runoff form. -SO42- and CO32- comes from surrounding geology Total Dissolved Solids High levels of dissolved salts can: -Wastewater plant The total mass of -Impair cell function in aquatic effluent dissolved solids per unit organisms -Urban runoff volume of water -Impact on crops -Agricultural runoff (esp. -Be unsatisfactory for stock in heavy fertilised areas) -Cause corrosion of irrigation equipment Hardness Difficult to use as it can: -Geology (esp. in Measure of ability of -Prevent effective washing limestone areas) water sample to lather -Cause blockages of pipes as Ca2+ -Industrial influences soap (levels of Mg2+ and precipitates in presence of CO32- (e.g. cement dust) Ca2+) Turbidity High amounts of suspended solids can: -Urban runoff (esp. in Measures of the -Smother gills (suffocation) construction areas) suspended solids in -Block entry of light into water and -Roads Ability of the sample of limit photosynthesis -Agricultural areas (esp. scatter light -Impair recreational waters cleared or turned -Damage irrigation equipment (e.g. ground) blockage) Excessive changes to pH can: -Agricultural runoff (esp. Acidity Measure of the pH -Damage cell function manures and composts) (acidity/alkalinity) of -Damage egg hatching and spawning -Acidic mine drainage sample -Increase levels of toxic metals and -Acid rain ammonia being released into environment Dissolved Oxygen Low levels of DO can: -Aquatic plants and algae Measures of amount of -Result in suffocation of organisms supply DO, but too much oxygen dissolved in the -Change water pH (toxicity effects) leads to swings water High levels or varying DO levels can:
Part 5: Water Monitoring and Management Determining Water Quality Definition Impacts Possible Sources Cations, metal cations Positively charged ions Unhealthy balance of cations can impair cell functioning. Most heavy metals are toxic to living things, with organisms higher in food chain being more vulnerable. -Industrial discharge -Mine drainage -Road runoff -Atmospheric pollution Anions Negatively charged ions Nitrates and phosphates can cause eutrophication. If DO is low, sulfates can form H2S. If acidic, H2SO4 can form. -NO3- and PO43- come from ag. and urban runoff -SO42- and CO32- comes from surrounding geology Total Dissolved Solids The total mass of dissolved solids per unit volume of water High levels of dissolved salts can: -Impair cell function in aquatic organisms -Impact on crops -Be unsatisfactory for stock -Cause corrosion of irrigation equipment -Wastewater plant effluent -Urban runoff -Agricultural runoff (esp. in heavy fertilised areas) Hardness Measure of ability of water sample to lather soap (levels of Mg2+ and Ca2+) Difficult to use as it can: -Prevent effective washing -Cause blockages of pipes as Ca2+ precipitates in presence of CO32- -Geology (esp. in limestone areas) -Industrial influences (e.g. cement dust) Turbidity Measures of the suspended solids in Ability of the sample of scatter light High amounts of suspended solids can: -Smother gills (suffocation) -Block entry of light into water and limit photosynthesis -Impair recreational waters -Damage irrigation equipment (e.g. blockage) -Urban runoff (esp. in construction areas) -Roads -Agricultural areas (esp. cleared or turned ground) Acidity Measure of the pH (acidity/alkalinity) of sample Excessive changes to pH can: -Damage cell function -Damage egg hatching and spawning -Increase levels of toxic metals and ammonia being released into environment -Agricultural runoff (esp. manures and composts) -Acidic mine drainage -Acid rain Dissolved Oxygen Measures of amount of oxygen dissolved in the water Low levels of DO can: -Result in suffocation of organisms -Change water pH (toxicity effects) High levels or varying DO levels can: -Aquatic plants and algae supply DO, but too much leads to swings
Chemistry_Notes_-_Chemical_Monitoring_and_Management_by_Jonathan_Chan.docx