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Cross-border network for knowledge transfer and innovative development in wastewater treatment WATERFRIEND HUSRB/1203/221/196 1st HUSRB Students Meeting. 1st Students Meeting Waterfriend. Wastewater and certain methods for its analysis

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  1. Cross-border network for knowledge transfer and innovative development in wastewater treatmentWATERFRIENDHUSRB/1203/221/1961st HUSRB Students Meeting

  2. . 1st Students Meeting Waterfriend . Wastewater and certain methods for its analysis Božo Dalmacija, Jasmina Agbaba, Malcolm Watson University of Novi Sad Faculty of Sciences, Trg Dositeja Obradovića 3, 21000 Novi Sad

  3. . 1st Students Meeting Waterfriend Wastewater -water which is contaminated in any way during use. .

  4. . 1st Students Meeting Waterfriend . Water polluters:

  5. . 1st Students Meeting Waterfriend According to its origin, wastewater can be classed as: . • municipal wastewater - water used in households, institutions, schools, hospitals, etc.; • industrial wastewater - used water from industrial plants; • wastewater from livestock facilities (farms) - usually wet manure removed from breeding pigs and so on; • atmospheric waste water - rainfall which flows from the city and industrial areas and which can contain various materials found locally; and • drainage wastewater from landfills containing municipal and other waste.

  6. . 1st Students Meeting Waterfriend Municipal wastewater . • Long term constant composition in a region, as a result of the standard of living and way of life of the population. • Pollution amounts and loads may be expressed using norms, i.e. standard values per unit population • (PE - Population Equivalent) Table 1. Pollution by PE

  7. . 1st Students Meeting Waterfriend . • The amount and composition of municipal wastewater shows typical variations during the day as a result of the rhythm of life of the population. • Certain variations in flow and composition may also occur during the year. rainy period Flow m3/s dry period S M T W T F S Figure 1. Usual daily and weekly variation of municipal wastewater Rural centres - below 150 l / capita per day, Urban areas - 200 l / capita per day.

  8. . 1st Students Meeting Waterfriend . • The smaller the sewage system and the lower the population served by the sewage system, the greater the daily variation, i.e. the greater the ratio between the maximum and medium flows Figure 2. Daily fluctuations in municipal wastewater: flow: 34500 m3/day; suspended matter: 9620 kg/day; BOD5: 7420 kgO2/day;total nitrogen: 1620 kgN/day

  9. . 1st Students Meeting Waterfriend . Table2. Characteristics of municipal wastewater

  10. . 1st Students Meeting Waterfriend Industrial wastewater . Industrial wastewaters often have variable character, both in quantity and in quality. Wastewaters vary by type of industry, but also frequently between the same type of factory, as a consequence of differences in production techniques, raw materials, hours worked, etc. Figure 3. Example of an industrial wastewater daily flow

  11. . 1st Students Meeting Waterfriend . • Industrial wastewater can be divided into four categories depending on its quality and method of formation: • technological wastewater • specific wastewater • useful discharge • occasional discharge

  12. . 1st Students Meeting Waterfriend . • The quantity and quality of industrial wastewater depends on: • industrial activity, plant capacity and raw materials used; • ability to recycle or separate different wastewater streams; • daily wastewater amounts of each type; • average and maximum daily amounts (frequency and duration) of water; • average and maximum flows of pollutants (frequency and duration) for each specific waste discharge.

  13. . 1st Students Meeting Waterfriend . Monitoring of wastewater The selection of monitoring parameters depends on the: • manufacturing process, • raw materials and • chemicals used in the plant/factory. Wide range of monitoring frequencies according to the needs and depending on the risk posed to the recipient ecosystem, and in accordance with the monitoring approach undertaken.

  14. . 1st Students Meeting Waterfriend . • Large numbers of factories/companies - various pollutants in their wastewater. • Analytically irrational and economically unjustified to analyse all possible pollutants. • Parameters are therefore grouped according to the activities performed by the polluter and currently applied technology. • In all these cases, there is a certain number of parameters common to this type of wastewater - "general parameters".

  15. . 1st Students Meeting Waterfriend . Table 3. General wastewater parameters

  16. . 1st Students Meeting Waterfriend . • “Specific parameters“ - parameters that characterize different activities, technological processes, and in some cases differences in production organization. • These parameters are defined after examining the production process and defined for wastewaters in certain factories or companies.

  17. . 1st Students Meeting Waterfriend . Table 4. Examples of specific parameters by industrial activity

  18. . 1st Students Meeting Waterfriend .

  19. . 1st Students Meeting Waterfriend .

  20. . 1st Students Meeting Waterfriend .

  21. . 1st Students Meeting Waterfriend . • Flow measurements • quality of wastewater irrelevant if quantity not known • Closed pipe flow • magnetic, ultrsonic: generally require pipe to be kept full • Open channel • Primary measuring device – weir/flume • non contacting level measuring device – radar/ultrasonic • easier maintenance, easier to use

  22. . 1st Students Meeting Waterfriend . • Preliminary wastewater testing - quick qualitative or semi-quantitative tests, carried out by spectroscopic, micro - and macro chemical methods. • Full program of work – based on the preliminary results, a methodolgy must be made for the analyst to follow when analyzing the samples.

  23. . 1st Students Meeting Waterfriend . • Preliminary testing - allows the analyst to correctly determine: • the amount of water required for testing, • the number of special samples to be taken, • specific requirements for the taking and storage of individual samples, • the proper selection of analytical methods, and • any links between the presence of one component or water property with the absence of an other.

  24. . 1st Students Meeting Waterfriend . problem wastewater sampling strategy interpretation investigation of wastewater sample wastewater sampling characterisation chemical information error data analysis analytical result wastewater sample measured value investigation of wastewater sample prep. meas. assess.

  25. . 1st Students Meeting Waterfriend Sampling . • Proportional to time.Take the same amount of sample (q=constant) at the same time interval (t=constant) and the composite sample is defined by a certain time interval. • Proportional to flow. • Take different amounts of sample proportional to the wastewater flow (q=kQ) at the same time interval (t=constant); Figure 4. Different sampling possibilities • Take the same amount of sample (q=constant) at different time intervals depending on the wastewater flow (t=kQ).

  26. . 1st Students Meeting Waterfriend . Tabela 5. Sample definitions If the wastewater sample is not representative, either at the time of sampling or the time of analysis, even the most careful analysis will not be useful.

  27. . 1st Students Meeting Waterfriend . • According to the nature of the components that need to be determined, samples can be classified into two groups: • samples taken for the determination of characteristics and contents which change in contact with air, and • samples taken for the determination of properties that do not change in contact with air.

  28. . 1st Students Meeting Waterfriend Water samples for air-sensitive parameters . • Require the use of specific sampling methods - to avoid sample contact with air, sample containers must be immediately sealed or conserved. • Separate samples must be taken for the determination of air sensitive components, such as: acidity/alkalinity, ammonia and ammonium ions, CO2, Fe2+ and Fe3+, dissolved oxygen, nitrites, residual chlorine, chlorine demand, pH, hardness, phenols, H2S and sulphides, SO2, sulphites and bisulphites. • It is even necessary to carry out some analyses on the spot, during or immediately after taking the sample (dissolved gases, pH, suspended solids).

  29. . 1st Students Meeting Waterfriend Water samples for air-non sensitive parameters . • Composite sample is usually taken - it is still necessary to take precautions against possible contamination of the sample solids from the air. • From one composite sample, the following parameters may be determined: organic substances, suspended solids, nitrates, phosphates, calcium and magnesium, sulphates, total iron and other metals. • Separate samples are taken for the determination of substances extracted by some solvent (grease, suspended matter, detergents).

  30. . 1st Students Meeting Waterfriend . • Samples taken for wastewater parameters which do not change in contact with the air may or may not be filtered prior to analysis, depending on the nature and quantity of insoluble material, and the applied method of measurement. • According to the purpose of the investigation and the components to be determined, analysis might include: • only the aqueous phase, • only the solid phase, or • the entire system.

  31. . 1st Students Meeting Waterfriend . • For the analysis of gaseous wastewater components (oxygen, CO2, H2S), prior filtration of the sample is not allowed, in order to prevent the loss of these components. • If filtration is not allowed, as outlined in the analytical method, the precipitate may be separated by centrifugation, clarification by standing, etc.

  32. . 1st Students Meeting Waterfriend . An intelligent and meaningful concept of laboratory analysis includes:

  33. . 1st Students Meeting Waterfriend . • Today, there are many known methods for the qualitative detection and quantitative determination of pollutants in wastewater, and they are continuously improving. • The choice of method depends on the • purpose and goals of the wastewater investigation and the information desired, • from the concentration of components determined (the maximum allowable concentrations of pollutants prescribed by regulations are often highly relevant), • the type of results required (approximate, accurate and correct results), • the instrument and chemicals that are available, • to possible analytical limitations due to interference and others.

  34. . 1st Students Meeting Waterfriend Methods can be classified according to their purpose: . • Reference (standard) methods • Rapid or screening methods • Routine methods • Automated methods • Modified methods

  35. . 1st Students Meeting Waterfriend Reference (standard) methods: . • Standards of the International Organization for Standardization (ISO), • Standard Methods for the Examination of Water and Wastewater published by the American Public Health Organization (APHA), • American Waterworks Association (AWWA) • Water Pollution Control Federation (WPCF), • Environmental Protection Agency (EPA) .

  36. . 1st Students Meeting Waterfriend Rapid or screening methods: . • used for preliminary testing of a large number of samples, as an expedient means of determining whether any sample must be subjected to additional testing with more accurate methods. Routine methods: • official or standard, but may be modified to be better suited for application with a large number of similar samples.

  37. . 1st Students Meeting Waterfriend Automated methods: . • using automated equipment, which can also be official or rapid methods. Modified methods: • can be are official or standard methods that have been modified in order to simplify them or adapt them to different types of samples from the original planned method, or to remove abnormal interfering substances. .

  38. . 1st Students Meeting Waterfriend . • Non-standard methods, and those that are published by reputable scientific journals or research companies. • The choice of optimal method is very important • compliance with the quality assurance program based on scientific and technical information, • consideration of practical requirements (time and cost of wastewater analysis, the accuracy and precision of analytical instruments, and the experience and skills of the analyst, etc).

  39. . 1st Students Meeting Waterfriend . Simple, quick and inexpensive determination of multiple parameters .

  40. . 1st Students Meeting Waterfriend . • If there is a choice between several good methods, preference is given to: • the method recommended by the relevant international organizations, • methods validated by interlaboratory tests conducted in accordance with international protocols, • methods validated in the required concentration range, • methods which are often applied, are simple, fast and economical, • methods applicable to samples similar to those investigated, • methods applicable to different sample types, and materials and • methods which allow for the traceability of each result.

  41. . 1st Students Meeting Waterfriend Analytical method selection .

  42. . 1st Students Meeting Waterfriend .

  43. . 1st Students Meeting Waterfriend . The most important quality parameters of an analytical method

  44. . . 1st Students Meeting Waterfriend . . • Accuracy is defined as the degree of agreement with the actual measured or expected value. • Accuracy is measured by comparing the response of the method to the real value, and is expressed as the recovery. • Analysis of a Certified Reference Material –CRM • Determination of percentage yield - Recovery • Comparison with other methods already confirmed to be accurate

  45. . 1st Students Meeting Waterfriend . • Precision is the degree of mutal agreement between individual measurements made under the same conditions. • Can be expressed using different statistical indicators: • standard deviation, • relative standard deviation (RSD).

  46. precision accuracy . 1st Students Meeting Waterfriend .

  47. . 1st Students Meeting Waterfriend Limit of Detection (LoD) and Limit of Quantitation (LoQ) .

  48. . 1st Students Meeting Waterfriend . • Instrument detection limit (IDL) the concentration of analyte that gives a signal five times the signal/noise ratio • Method detection limit (MDL, LoD) lowest concentration of an analyte which can be measured and reported with 95% confidence that the analyte concentration is greater than zero. • Criterion of detection CD = t0.95(f) * Sbl * √ (1 + 1/n) • Limit of detection LoD = 2 * CD • t0.95 – from Student’s table • (f) – number of measurements used for Sbl • Sbl - standard deviation of blank • n – number of blanks during routine analysis (2)

  49. . 1st Students Meeting Waterfriend . • Practical quantitation limit (PQL, LoQ), the lowest concentration that can be determined reliably – in the laboratory using routine procedures. LoQ = Xaverage blank + 10 * Sbl • LoQ = Xaverage blank + 5 * LoD • Xaverage blank – average value of blank or sample with extremely low level of analyte • Sbl – standard deviation of blank

  50. . 1st Students Meeting Waterfriend . • Specific methods allow determination of one analyte, irrespective of the presence of other components • Selective methods allow for the determination of more than one similar analytes at the same time, irrespective of the presence of other potentially interfering components • May be necessary to remove or mask such interferences.

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