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Understand the importance of chemical parameters such as pH, turbidity, coliforms, nitrates, and nitrites in water analysis. Learn sampling procedures, laboratory testing, and treatment methods to ensure water quality. Follow international guidelines for safe water management.
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Contents • Chemical parameters and ranges • Water sources: Sampling procedures • Laboratory • Water sources: Analysis implementation and recording • Water treatment: Analysis implementation and recording • Water quality control process summary
Turbidity: Suspended matter that acts a shield protecting virus and bacteria against their destruction by a disinfectant plus the dirtiness and unpleasant visual and tasting aspects. pH: Measure of water acidity or alkalinity. It has to have certain value to in order to Aluminium Sulphate being effective. Coliforms: Presence of faecal matter that might cause a whole range of diarrheic diseases that can be fatal. Nitrates: They are not toxic but they show the presence of fertilizers and other compounds more dangerous such as nitrites. Nitrites: They are harmful for human health. In high concentrations, they show the presence of industrial contamination an/or domestic waste water. CHEMICAL PARAMETERS
Aluminium:It is important to determine that the quantity of Aluminium Sulphate added to a water treatment process is not excessive. Otherwise, high concentrations of this compound might be harmful to humans. Hardness:Hardness is due to Magnesium and Calcium salts. It is no related to health problems although it produces very unpleasant taste when values are higher than those recommended by WHO. Conductivity:It is an indicator of water salinity that must not be higher than certain limits, otherwise it might be harmful to health. Salt water has a conductivity of 45,000 µS/cm and average fresh water conductivity is less than 2.500 µS/cm. CHEMICAL PARAMETERS
RANGES ------- EUROPEAN UNION (Directive 98-83 CE) pH = 6,5 – 9 Cl- (water distribution) ≈ 0,6 -1 ppm (check with local authorities) Conductivity < 2.500 µS/cm (20ºC) Nitrites = 0,5 ppm. (see note) Nitrates = 50 ppm. (see note) Aluminium = 0,2 ppm Bacteriological = 0 cfu (water consumption point) Note:Ensure that the value of 0,10 mg/l for nitrites is met at the outlet of water treatment facilities. Likewise, the condition that [nitrates]/50 + [nitrites]/3 # 1 is observed, where the brackets mean concentrations in mg/l for nitrates (NO-3) and for nitrites (NO-2).
Concentration: 1 g/m3 <> 1 mg/l<> 1 ppm 1 g <> 1000 mg 1 m3 <> 1000 l 1 mg <> 1.000 mg 1 mg/l <> 1000 mg/l Turbidity: NTU (Nephelometric Turbidity Unit ) Coliforms: cfu (colony forming unit) Conductivity:µS/cm UNITS
SAMPLING PROCEDURE The way that sampling is carried out might definitely distort the final results.
SAMPLING PROCEDURE • Sampling is carried out in representative manner. • Date, time, sampling location are registered (Field log book). • Samples kept in safe and cool place. • Always value how, where and why a water source is selected, ensuring that the water can be treatable and safe for human consumption.
SAMPLING PROCEDURE • Avoid any direct contact with water If feasible. It might be sufficient to acquire diseases.
3.Avoid the surface or the bottom since due to flotation or sedimentation these concentrate materials, chemicals, bacteria… Sample is best taken 30 cm below surface. 2.Take sample where properties are best describing the source. For instance, we will avoid the vicinities of a sewage discharge pipe.
4.Clean sample collecting vessel with sample water, never with chemical or other water, including tap water. 5.If sampling piped water, leave running for 1 minute before taking the sample. 6.Do not allow foreign material or waters to touch water collecting vessel. 7.Label results with appropriate information, date, place and any other parameter that may hold importance (Field Log Book)
TEST CAPABILITY TurbiditypHColiformsNitrates NitritesAluminiumChlorineHardness ConductivityTemperatureJar test Chlorine demand essay LABORATORY
LABORATORY MAINTENANCE IMPORTANT • Always handled the equipment with care. It is fragile. • Carefully clean and dry all items before introducing them in the laboratory box. • Protect the most fragile items with appropriate packaging. • Dispose the items in the right place inside the laboratory box. • Be organised and methodical when using the items and chemicals, and implementing any test.
OXFAM DELAGUA KIT • Coliforms • Turbidity • pH • Chlorine
SELECTION OF WATER SOURCES ≤ 180 ≤2.500 6,5 ≤ ≤ 9,5 ≤ 50 ≤ 0,5
TURBIDITY ≤ 5 ≤ 20 (Turbidity tests are needed on weekly basis and when visual inspection shows some changes in water qualities)
COLIFORMS, ALUMINIUM AND HARDNESS (Outlet of water treatment plant) ≤ 0,2 0 CFU
DATE____________ SITE____________________ RESIDUAL CHLORINE (mg/l) 0.6 – 1.0 0.1 – 0.3 Chlorine at the exit of the settlement tank: 0,1 mg/l – 0.3 mg/l Residual chlorine at the exit of the plant: 0.6 mg/l – 1.0 mg/l
WATER DISTRIBUTION. RESIDUAL CHLORINE This table records the residual chlorine data obtained in the different places where the treated water from the SRC site is supplied. Samples should be taken from the taps. It is also convenient to specify where the water is supplied from a static tank or from a tanker directly to the users. The samples can be taken daily or randomly in different days. Residual chlorine at the taps: 0.3 mg/l – 0.6 mg/l
WATER ANALYSIS 6 < pH < 8 Nitrates < 50mg/l Nitrites < 0.5 mg/l Conductivity < 2,000 µS/cm Turbidity = NTU as low as possible Turbidity > 20 NTU: Aluminium Sulphate (Jar Test) Turbidity ≤ 20 NTU WATER TREATMENT PLANT Chlorine = 0.6 mg/l – 1.0 mg/l Aluminium < 0.2 mg/l Chlorine = 0.1mg/l – 0.3 mg/l Turbidity ≤ 5 NTU Chlorine = 0.3 mg/l – 0.6mg/l