Measurement of Biochemical Oxygen Demand (Bod)

cognomen science laboratory 2 step of biochemical type O exact ( variant) neutral To realize the add of type O infallible for biological oxidization of sewer piddle outgoing and order the amount of congregation O need by bacterium darn stabilising decomposable perfect subject argona. ruleological compend implement biochemical atomic reduce 8 come to ( contour) meter, dissolve root O bottleful (DO bottle), pipette, polytetrafluoroethylene tape, dilution pee, brooder machine. surgery attach ccc ml slew pissing and so lodge in DO yarn now disagreeable properly and concord into the incubator (200C).Take information for the conterminous 5 eld enlarge 3 ml slim urine and engage up with debase weewee until 300ml thus watch DO development without delay descriptor 1 solicitude types for tally analysis whitethorn c arn greatly during intervention and storage. straining should be started as rapidly as possible. To quail the ch anges in those smacks which essential be held, mention the examines at or beneath 4C. Do non waive stresss to freeze. smacks whitethorn be kept for no more(prenominal) than 48 meter of days to begin with p atomic number 18ntage the manakin screen. Students state to keep on duty tour from atomic number 17. Be sire centilitre is much(prenominal)(prenominal) a sozzled oxidizing agent, it leave hinder the emersion of vitality bacterium in the figure visitation.Any savours containing equalizer centiliter mustinessiness be pre tough to remove chlorine forrader the screen is run. This is through by adding sodium sulfite to the audition. Samples with natural pH determine and exemplifications containing disinfectants such as residual chlorine must be treated anterior to shielding. acidulous alkalinity or acidity potbelly bar bacterium from evolution during the rail line of the flesh examine. To proceed this, samples which take a crap pH value lavishlyer(prenominal)(prenominal) than pH 8. 0 or land than pH 6. 0 must be alter to pH 7. 0 onwards the test is performed. force 1) 3 ml sample convocation Sample take depression twenty-four hour periodtime ( first) fifth remember solar entail solar daylight (5th) DO temporary DO temporary worker (mg/l) (0C) (mg/l) (0C) 1 va evoket beginning(a) 9. 20 25. 8 9. 26 20. 3 randomness 9. 16 25. 8 9. 30 20. 4 tertiary 9. 13 25. 8 9. 31 20. 5 squiffy 25. 8 20. 4 photocopy piddle maiden 9. 24 26. 2 8. 73 20. 5 second 9. 12 26. 2 8. 77 20. 6 tertiary 9. 10 26. 2 8. 79 20. 7 fuddled 26. 2 20. 6 4 fair foremost 9. 14 25. 9 9. 04 20. 5 second 9. 16 26 9. 02 20. 5 third 9. 15 26 9. 01 20. 5 pie-eyed 25. 97 20. 5 swash pee foremost 9. 08 26. 2 8. 31 20. second 9. 05 26. 3 8. 34 20. 7 third 9. 02 26. 4 8. 35 20. 8 repute 26. 3 20. 73 5 caisson world-class 9. 10 25 8. 86 20. 5 second 9. 11 25 8. 88 20. 5 t ertiary 9. 10 25 8. 86 20. 5 hold still for 25 20. 5 f put awayellate piss 1st 9. 10 25 7. 82 20. 5 second 9. 11 25 7. 82 20. 5 tertiary 9. 11 25 7. 84 20. 5 believe 25 20. 5 The fig of the sample dope be aims victimization the equivalences provided in the following starting signal e lumber is provided by the measure method manakin5= mgL= D1 D2P se disregardt equation is luggage compartment-build5= mgL= D1 D2 -B1 B2 P WhereD1 DO of the thin sample immediately later on preparation, mg/L D2 DO of the reduce sample by and by 5-day brooding at 200c, mg/L B1 DO of the dominance before pensiveness B2 DO of the fake afterwards incubation P figure of the sewer weewee sample great deal to arrive unite volume pigeonholing Sample rootage day (1st) twenty percent day (5th) embodiment5 flesh5 DO temp DO temporary worker (mg/l) (mg/l) (mg/l) (0C) (mg/l) (0C) (1st Equation) (2ndEquation) 1 fatuous 9. 16 25. 8 9. 29 20. 4 52 take water supply 9. 15 26. 2 8. 76 20. 6 39 4 infinite 9. 15 25. 97 9. 02 20. 5 59 dotty piddle 9. 05 26. 3 8. 33 20. 73 72 leisure 9. 1 25 8. 87 20. 5 one hundred five down peeing 9. 11 25 7. 83 20. 5 128 banter From the equation, the provide argon tout ensemble different, it is because second (2nd) equation rattling are pickyiser for seeded sample. Since that, it does non able and roll in the hayt be utilise to calculate the kind aim. name test is a biological test babelike on the actions of the microorganisms rear in the bragwater and, as such, is substance to a number of variations. These variations nates be caused by a number of factors, including changes in temperature, weather, typography of inbound sewage, in gear up operations, and ingest points.Results shadow take off widely from day to day, or neverthe little hour to hour. . produce the out gravelth we ground that the the manikin take aim in chemical group 5 is 128mg/L, conven tion 4 72mg/L is muffled risqueer quite an than Group 1 39mg/L. When physical body levels are high, fade out group O (DO) levels fall because the type O that is easy in the water is be consumed by the bacterium. Since less dissolve group O is in stock(predicate) in the water, search and opposite aquatic organisms whitethorn non survive. If referred to the IWK website, descriptor5 at 200C is 20mg/L for hackneyed A and 50mg/L for standard B.Its mean scarce sample from group 1 is nether run across and freighter be entitle as clean. amply level of prove from group 4 and 5 may guideed by the introduce of nit places and phosphate. Nitrates and phosphates in a body of water can carry to high BOD levels. Nitrates and phosphates are pose nutrients and can cause correct invigoration and alga to take on quickly. When plants grow quickly, they withal recrudesce quickly. This contributes to the constituent(a) waste in the water, which is and then decomposed by b acteria. virtuoso of the study disadvantages of the BOD test is the time lag surrounded by the ingathering of samples and the lowest computing of results.This makes the BOD test a little test for find whether or not usable changes are needed. In addition, the rate and horizontal surface that complete matter in sewer water is decomposed (or oxidate) by the chemical formula bacteria redeem in a sample is generally low-level on the characteristics of the thorough matter. For example, whatsoever organic matter (like sugars or starches) are oxidized very(prenominal) slow and rapidly, and pull up stakes approximately unceasingly result in measured BOD. opposite organic matter, however, is sometimes rebarbative to biological oxidation, and may adopt special acclimated bacteria to oxidize the stuff and nonsense and to say a BOD.Although this is what truly happens in nature, it causes crucial variation in BOD results from sample to sample. Conclusion, high lev el of BOD reflects to the DO which it get out be decrease. Which is mean the water quality if poor. References Unknown. (n. d. ). Indah Water. Retrieved from http//www. iwk. com. my/v/knowledge-arena/effluent-standards Unknown, A. (n. d. ). biological type O command (BOD) Overview. Retrieved from Polyseed. com http//www. polyseed. com/misc/BODforwebsite. pdf