Lecture # 2 Water Quality Standards ParameterConcentration (mg/L) Alkalinity (as CaCO 3 ) Ammonia (NH 3 -N unionized) < (Salmonids) Ammonia (TAN) Cool-water fish <1.0 Ammonia (TAN) Warm-water fish <3.0

Water Quality Standards ParameterConcentration (mg/L) Hardness, Total (as CaCO 3 ) >100 Iron (Fe) <0.15 Nitrogen (N 2 ) <110% total gas pressure <103 % as nitrogen gas Nitrite (NO 2 ) <1, 0.1 in soft water Nitrate (NO 3 ) or higher

Water Quality Standards ParameterConcentration (mg/L) Oxygen Dissolved (DO)>5 > 90 mm Hg partial pressure Ozone (O 3 )<0.005 pH Salinity <0.5 to 1 Total dissolved solids (TDS) <400 Total suspended solids (TSS) <80

Water Quality Parameters Dissolved Oxygen Temperature Ammonia/Nitrite/Nitrate pH Alkalinity/Hardness Salinity Carbon Dioxide Solids Critical Parameters Important Parameters

Dissolved Oxygen :oxygen solubility decreases as temperature and salinity increase. Temperature: cold-water species below 15 ° C cool-water species between 15 °- 20° C. warm-water species above 20° C. Ammonia, nitrite, and nitrate are all highly soluble in water. Ammonia exists in two forms: un-ionized NH 3 and ionized NH 4 +. total ammonia-nitrogen (TAN = NH 4 + –N + NH 3 –N) pH : Seawater: , Freshwater: 6.5 – 9.0

Alkalinity Alkalinity ( mg/l as Ca CO 3 ) FormulaCommon NameEquivalent Weight NaOHsodium hydroxide40 Na 2 CO 3 sodium carbonate53 NaHCO 3 sodium bicarbonate83 CaCO 3 Calcium Carbonate50 CaOslaked lime28 Ca(OH) 2 hydrated lime37

Hardness soft (0-75 mg/L moderately hard (75 – 150 mg/L) hard ( mg/L) very hard (> 300 mg/L) Classified as: Recommended range: 20 to 300 mg/L CaCO 3

Solids – settleable, suspended, dissolved Three categories: settleable suspended fine or dissolved solids size classification of solids in water

Measurements – Dissolved Oxygen

Measurements - Temperature Off-the-self-components and hardware. Included with most DO, pH, conductivity meters. NOT RECOMMENDED! Mercury thermometers

Measurements - pH Both laboratory and field instruments readily available.

Measurement – CO 2 Measurement of pH and Alkalinity yields CO 2 Alkalinity 100 mg/L

Chemical Analysis Test Kits and Colorometers

Chemical Analysis – Dissolved Oxygen Winkler Method: manganous sulfate, potassium iodide, sodium hydroxide manganous ion + oxygen  manganous dioxide (proportional to dissolved oxygen concentration) sulfuric acid causes the oxidation of iodide to iodine by the manganous dioxide. Titration with sodium thiosulfate with starch indicator (iodine concentration proportional to DO concentration

Chemical Analysis – CO CO 2 Carbon Dioxide Free CO 2 reacts with sodium hydroxide ( N) to form sodium bicarbonate; completion indicated using a pH meter (8.3) or phenolphthalein indicator. 1 ml of NaOH equals 1 mg/LCO 2.

Chemical Analysis - Alkalinity 2320 – Titration Method Titration with 0.02 N Sulfuric Acid with methyl orange indicator end point (4.5 pH) 1 ml titrant equals 10 mg/L CaCO 3.

Chemical Analysis – Ammonia, Nitrite and Nitrate Ammonia: colorimetric Nesslerization ion specific electrodes Nitrite:colorimetric Nitrate:reducing to nitrite with cadmium catalyst, measure nitrite. ion specific electrode

Chemical Analysis - Solids 2540 Solids A well-mixed sample is filtered through a weighed standard glass-fiber filter and the residue retained on the filter is dried to a constant weight at 103 to 105 °C. The increase in the weight of the filter represents the total suspended solids.

Chemical Analysis - Orthophosphorus 4500-P Phosphorus Ammonium molybdate and potassium antimonyl tartrate react to form a heteropoly acid, which is reduced with to intensely colored molybdenum blue by ascorbic acid..

Laboratory A water quality lab doesn’t have to be large, but it should be dedicated only to that task.

Table 3: Treatment systems used to remove the major contaminants ContaminantTreatment systemClassification Suspended solidsScreening and comminution Sedimentation Flotation Filtration Coagulation / sedimentation Land treatment P C / P P Biodegradable organics Activated sludge Trickling filters Rotating biological contactors Aerated lagoons Oxidation ponds Intermittent sand filtration Land treatment Physical / Chemical B P / B B / C / P P / C PathogensChlorination Ozonation Land treatment CCPCCP

Nutrients: Nitrogen Suspended-growth nitrification and denitrification Fixed-film nitrification and denitrification Ammonia stripping Ion exchange Breakpoint Chlorination Land treatment B C/P C B /C / P PhosphorusMetal salt coagulation / Sedimentation Lime coagulation / sedimentation Biological / chemical phosphorus removal Land treatment C / P B / C C / P Refractory organicsCarbon adsorption Tertiary ozonation Land treatment systems PCPPCP Heavy metalsChemical precipitation Ion exchange Land treatment C C / P Dissolved inorganic solids Ion exchange Reverse osmosis Electrodialysis CPCCPC B = biological, C = Chemical, P = physical

Drinking water standard ParameterStandard Physical Parameters Colour10 to 20 (Platinum-cobalt scale) Odour0 to 4 P o value Temperature10 °C to 15.6 °C Turbidity5 to 10 ppm TasteNo objectionable taste Chemical Parameters pH6.5 to 8 Hardness7.5 to 115 ppm (CaCO 3 equivalent) Total Solids< 500 ppm Chlorides< 200 ppm Iron and Manganese< 0.30 ppm Dissolved oxygen5 to 6 ppm Lead0.10 ppm Arsenic0.05 ppm sulphate< 20 ppm BODNil Biological Parameters B-coliNo B-coli in 100ml