Chidziwitso chokhudza chowunikira cha COD BOD

Kodi BOD ndi COD zimayesedwa bwanji?

Pali njira zingapo zomwe zingagwiritsidwe ntchito poyeza BOD (Biological Oxygen Demand) ndi COD (Chemical Oxygen Demand) m'madzi. Nayi chidule cha njira ziwiri zazikulu:

Njira Yosungunula: Mu njira yosungunula, kuchuluka kwa madzi komwe kumadziwika kumachepetsedwa ndi kuchuluka kwa madzi osungunula, komwe kumakhala ndi zinthu zachilengedwe zochepa kwambiri. Kenako chitsanzo chosungunula chimayikidwa mu incubation kwa nthawi inayake (nthawi zambiri masiku 5) kutentha kolamulidwa (nthawi zambiri 20°C). Kuchuluka kwa mpweya mu chitsanzo kumayesedwa isanayambe komanso itatha. Kusiyana kwa kuchuluka kwa mpweya musanayambe komanso itatha kusungunuka kumagwiritsidwa ntchito kuwerengera BOD ya chitsanzo.

Poyesa COD, njira yofanana imatsatiridwa, koma chitsanzocho chimachiritsidwa ndi mankhwala ophera oxidant (monga potassium dichromate) m'malo mochiika mu incubation. Kuchuluka kwa mpweya womwe umadyedwa ndi mankhwalawo kumagwiritsidwa ntchito kuwerengera COD ya chitsanzocho.

Njira yoyezera mpweya: Mu njira yoyezera mpweya, chidebe chotsekedwa (chotchedwa respirometer) chimagwiritsidwa ntchito poyesa momwe mpweya umagwiritsidwira ntchito ndi tizilombo toyambitsa matenda pamene tikuswa zinthu zachilengedwe m'madzi. Kuchuluka kwa mpweya mu respirometer kumayesedwa kwa nthawi inayake (nthawi zambiri masiku 5) pa kutentha kolamulidwa (nthawi zambiri 20°C). BOD ya chitsanzocho imawerengedwa kutengera liwiro lomwe kuchuluka kwa mpweya kumachepa pakapita nthawi.

Njira yochepetsera madzi ndi njira yoyezera mpweya ndi njira zokhazikika zomwe zimagwiritsidwa ntchito padziko lonse lapansi poyesa BOD ndi COD m'madzi.

Kodi malire a BOD ndi COD ndi otani?

BOD (Biological Oxygen Demand) ndi COD (Chemical Oxygen Demand) ndi miyeso ya kuchuluka kwa mpweya wofunikira kuti uswe zinthu zachilengedwe m'madzi. Mlingo wa BOD ndi COD ungagwiritsidwe ntchito poyesa ubwino wa madzi ndi momwe madzi otayira angakhudzire madzi m'madzi achilengedwe.

Malire a BOD ndi COD ndi miyezo yomwe imagwiritsidwa ntchito poyang'anira kuchuluka kwa BOD ndi COD m'madzi. Malire awa nthawi zambiri amakhazikitsidwa ndi mabungwe olamulira ndipo amachokera pa kuchuluka kovomerezeka kwa zinthu zachilengedwe m'madzi komwe sikudzakhudza chilengedwe. Malire a BOD ndi COD nthawi zambiri amafotokozedwa mu ma milligram a mpweya pa lita imodzi ya madzi (mg/L).

Malire a BOD amagwiritsidwa ntchito polamulira kuchuluka kwa zinthu zachilengedwe m'madzi otayidwa omwe amatulutsidwa m'madzi achilengedwe, monga mitsinje ndi nyanja. Kuchuluka kwa BOD m'madzi kumatha kuchepetsa mpweya m'madzi ndikuwononga zamoyo zam'madzi. Chifukwa chake, malo oyeretsera madzi otayidwa amafunika kukwaniritsa malire enaake a BOD akamatulutsa zinyalala zawo.

Malire a COD amagwiritsidwa ntchito powongolera kuchuluka kwa zinthu zachilengedwe ndi zinthu zina zodetsa m'madzi otayidwa m'mafakitale. Kuchuluka kwa COD m'madzi kumatha kusonyeza kukhalapo kwa zinthu zoopsa kapena zoopsa, komanso kungachepetse kuchuluka kwa mpweya m'madzi ndikuwononga zamoyo zam'madzi. Malo opangira mafakitale nthawi zambiri amafunika kukwaniritsa malire enaake a COD akamatulutsa madzi otayidwa.

Ponseponse, malire a BOD ndi COD ndi zida zofunika kwambiri poteteza chilengedwe ndikuwonetsetsa kuti madzi ali bwino m'madzi achilengedwe.