39.Gịnị bụ mmiri acidity na alkalinity?
Acidity nke mmiri na-ezo aka n'ọtụtụ ihe dị na mmiri nke nwere ike imebi ntọala siri ike. Enwere ụdị ihe atọ na-etolite acidity: acids siri ike nke nwere ike kewaa H + kpamkpam (dị ka HCl, H2SO4), acid na-adịghị ike nke na-ekewa H+ (H2CO3, organic acids), na nnu nke nwere acid siri ike na ntọala ndị na-adịghị ike (dịka. NH4Cl, FeSO4). A na-atụ acidity site na titration nwere ngwọta ntọala siri ike. Acidity nke a tụrụ na oroma methyl dị ka ihe na-egosi n'oge titration ka a na-akpọ methyl orange acidity, gụnyere acidity nke ụdị mbụ nke acid siri ike kpụrụ na ụdị nke atọ nke nnu acid siri ike; acidity tụrụ na phenolphthalein dị ka ihe ngosi a na-akpọ phenolphthalein acidity, Ọ bụ nchikota nke ụdị acidity atọ dị n'elu, ya mere a na-akpọkwa ya mkpokọta acidity. Mmiri okike n'ozuzu anaghị enwe acidity siri ike, mana ọ nwere carbonates na bicarbonates nke na-eme ka mmiri dị alkaline. Mgbe acidity dị na mmiri, ọ na-apụtakarị na mmiri ahụ ejirila acid metọọ ya.
N'adịghị ka acidity, mmiri alkalinity na-ezo aka n'ọtụtụ ihe dị na mmiri nke nwere ike wepụ acids siri ike. Ihe ndị na-emepụta alkalinity gụnyere ntọala siri ike (dị ka NaOH, KOH) nke nwere ike kewaa OH kpamkpam, ntọala adịghị ike nke na-ekewa OH- (dị ka NH3, C6H5NH2), na nnu nke nwere ntọala siri ike na acid na-adịghị ike (dị ka Na2CO3). K3PO4, Na2S) na ngalaba atọ ndị ọzọ. A na-atụ alkalinity site na titration na ngwọta acid siri ike. The alkalinity tụrụ iji methyl oroma dị ka egosi n'oge titration bụ nchikota nke n'elu atọ ụdị alkalinity, nke a na-akpọ ngụkọta alkalinity ma ọ bụ methyl oroma alkalinity; A na-atụle alkalinity site na iji phenolphthalein dị ka ihe ngosi a na-akpọ phenolphthalein base. Degree, gụnyere alkalinity kpụrụ site ụdị mbụ nke ike isi na akụkụ nke alkalinity nke atọ ụdị ike alkali nnu.
Ụzọ nha nke acidity na alkalinity gụnyere titration egosi acid-base na titration potentiometric, nke a na-agbanwekarị na CaCO3 ma tụọ ya na mg/L.
40.Gịnị bụ pH uru mmiri?
Uru pH bụ logarithm na-adịghị mma nke ọrụ hydrogen ion na ngwọta mmiri tụrụ atụ, ya bụ, pH = -lgαH +. Ọ bụ otu n'ime ihe ndị a na-ejikarị eme ihe na usoro ọgwụgwọ nsị. N'okpuru ọnọdụ 25oC, mgbe pH uru bụ 7, ọrụ nke hydrogen ion na hydroxide ion na mmiri hà nhata, na ntinye uche kwekọrọ bụ 10-7mol / L. N'oge a, mmiri na-anọpụ iche, na pH uru> 7 pụtara na mmiri bụ alkaline. , na pH uru<7 means the water is acidic.
Uru pH na-egosipụta acidity na alkalinity nke mmiri, mana ọ nweghị ike igosi ozugbo acidity na alkalinity nke mmiri. Dịka ọmụmaatụ, acidity nke 0.1mol/L hydrochloric acid solution na 0.1mol/L acetic acid ngwọta bụkwa 100mmol/L, mana ụkpụrụ pH ha dị nnọọ iche. Uru pH nke 0.1mol/L hydrochloric acid ngwọta bụ 1, ebe uru pH nke 0.1 mol/L acetic acid ngwọta bụ 2.9.
41. Gịnị bụ usoro nha uru pH a na-ejikarị?
Na mmepụta n'ezie, iji mee ngwa ngwa na ngwa ngwa ịghọta mgbanwe na uru pH nke mmiri mkpofu na-abanye n'ụlọ ọrụ mmiri na-ekpofu mmiri, ụzọ kachasị mfe bụ iji akwụkwọ nyocha pH tụọ ya nke ọma. Maka mmiri mkpofu na-enweghị agba na-enweghị ihe ọ bụla kwụsịrị, a pụkwara iji ụzọ colorimetric mee ihe. Ka ọ dị ugbu a, usoro ọkọlọtọ obodo m maka ịlele uru pH nke ịdị mma mmiri bụ usoro potentiometric (usoro GB 6920–86 glass electrode). Ọ naghị emetụta ya na agba, turbidity, colloidal bekee, oxidants, na ndị na-ebelata ihe. Ọ nwekwara ike tụọ pH nke mmiri dị ọcha. Ọ nwekwara ike tụọ uru pH nke mmiri mkpofu ụlọ ọrụ merụru na ogo dị iche iche. Nke a bụkwa usoro a na-ejikarị atụle uru pH n'ọtụtụ osisi na-ekpofu mmiri.
Ụkpụrụ nke nleba potentiometric nke uru pH bụ iji nweta ikike nke electrode na-egosi, ya bụ, uru pH, site n'ịtụle ọdịiche dị n'etiti electrode iko na electrode ntụaka nwere ikike amara. Eletrọd ntụaka na-ejikarị calomel electrode ma ọ bụ Ag-AgCl electrode, na calomel electrode bụ ihe a na-ejikarị eme ihe. Isi ihe dị na pH potentiometer bụ ụda DC, nke na-eme ka ikike nke electrode na-emepụta ma gosipụta ya n'isi mita n'ụdị ọnụọgụ ma ọ bụ akara. A na-ejikarị ngwaọrụ nkwụghachi ụgwọ ọkụ na-eji ihe dị ike eme ihe iji dozie mmetụta okpomọkụ na electrodes.
Ụkpụrụ na-arụ ọrụ nke mita pH dị n'ịntanetị a na-eji eme ihe n'ụlọ ọrụ mmiri na-ekpofu mmiri bụ usoro potentiometric, na akpachara anya maka ojiji bụ otu ihe ahụ na nke mita pH ụlọ nyocha. Otú ọ dị, n'ihi na electrodes ndị a na-eji na-anọgide na-agbanye n'ime mmiri mkpofu ma ọ bụ tankị ikuku na ebe ndị ọzọ nwere nnukwu mmanụ ma ọ bụ microorganisms ruo ogologo oge, na mgbakwunye na-achọ ka mita pH kwadoro ya na ngwaọrụ nhicha akpaka maka electrodes, ntuziaka. A na-achọkwa ihicha dabere na ọnọdụ ịdị mma mmiri na ahụmịhe ọrụ. N'ozuzu, a na-eji aka na-ehicha mita pH nke a na-eji na mmiri ntinye ma ọ bụ tank aeration otu ugboro n'izu, ebe enwere ike iji aka na-ehicha mita pH nke a na-eji na mmiri na-asọ oyi otu ugboro n'ọnwa. Maka mita pH nke nwere ike tụọ okpomọkụ n'otu oge na ORP na ihe ndị ọzọ, a ga-edobe ya ma dokwa ya dịka nlezianya ojiji achọrọ maka ọrụ nha.
42.Kedu ihe echekwabara maka ịlele uru pH?
⑴Potentiometer kwesịrị idebe nkụ na uzuzu uzuzu, na-akwado ya mgbe niile maka mmezi, yana akụkụ njikọ ntinye nke electrode kwesịrị ịdị ọcha iji gbochie mmiri mmiri, ájá, mmanụ, wdg ịbanye. Gbaa mbọ hụ na ntọala dị mma mgbe ị na-eji ike AC. Igwe potentiometer nwere ike ibugharị na-eji batrị akọrọ kwesịrị dochie batrị mgbe niile. N'otu oge ahụ, a ga-ahazi potentiometer mgbe niile na zeroed maka nhazi na mmezi. Ozugbo emeziri nke ọma, ebe efu nke potentiometer na calibration na ndị na-ahụ maka nhazi enweghị ike ịtụgharị dịka ọchịchọ ya n'oge ule.
⑵ Mmiri a na-eji akwadebe ihe ngwọta ọkọlọtọ ọkọlọtọ na ikpochapụ electrode agaghị enwe CO2, nwee uru pH n'etiti 6.7 na 7.3, na ihe na-erughị 2 μs / cm. Mmiri ejiri anion na cation mgbanwe resin nwere ike izute ihe a chọrọ mgbe esichara ma hapụ ya ka ọ dị jụụ. A ga-emechi ihe ngwọta ọkọlọtọ a kwadebere ma chekwaa ya na karama iko siri ike ma ọ bụ karama polyethylene, wee chekwaa ya na friji na 4oC iji gbasaa ndụ ọrụ. Ọ bụrụ na echekwara ya n'ikuku ma ọ bụ n'ime ụlọ, ndụ ọrụ anaghị agafe ọnwa 1, enweghị ike iweghachite ihe nchekwa eji eme ihe na karama nchekwa maka ijikwa ya ọzọ.
⑶ Tupu nha nha, buru ụzọ lelee ma akụrụngwa, electrode, na ihe nchekwa ọkọlọtọ bụ ihe nkịtị. Na pH mita kwesịrị calibrated mgbe niile. Ọtụtụ mgbe usoro nhazi nhazi bụ otu ụzọ n'ụzọ anọ ma ọ bụ ọkara afọ, a na-ejikwa usoro nhazi nke isi ihe abụọ maka nhazi. Ya bụ, dị ka ọnụọgụ pH nke ihe nlele a ga-anwale, a na-ahọrọ ihe ngwọta abụọ ọkọlọtọ nke dị nso na ya. N'ozuzu, pH uru dị iche n'etiti ihe abụọ nkwụnye ihe ngwọta ga-abụ ma ọ dịkarịa ala karịa 2. Mgbe etinyere ya na ngwọta mbụ, nwalee ngwọta nke abụọ ọzọ. Ọdịiche dị n'etiti nsonaazụ ngosipụta nke potentiometer na ụkpụrụ pH ọkọlọtọ nke ngwọta nchekwa ọkọlọtọ nke abụọ ekwesịghị ịbụ ihe karịrị 0.1 pH unit. Ọ bụrụ na njehie ahụ karịrị 0.1 pH unit, a ga-eji ihe nchekwa nchekwa ọkọlọtọ nke atọ mee nnwale. Ọ bụrụ na njehie ahụ erughị nkeji 0.1 pH n'oge a, enwere ike inwe nsogbu na ngwọta nchekwa nke abụọ. Ọ bụrụ na njehie ahụ ka karịrị 0.1 pH unit, enwere ihe na-ezighị ezi na electrode na electrode kwesịrị ịhazi ma ọ bụ dochie ya na nke ọhụrụ.
⑷ Mgbe ị na-edochi ọkọlọtọ ọkọlọtọ ma ọ bụ ihe nlele, a ga-eji mmiri na-ekpo ọkụ na-ekpochapụ electrode zuru oke, na mmiri na-ejikọta ya na electrode kwesịrị itinye akwụkwọ nzacha, wee kpochaa ya na ngwọta a ga-atụle iji kpochapụ mmetụta nke ibe. Nke a dị mkpa maka iji buffers na-adịghị ike. Nke a dị mkpa karịsịa mgbe ị na-eji ngwọta. Mgbe ị na-atụle uru pH, a ga-akpalite ngwọta mmiri mmiri nke ọma iji mee ka ngwọta ahụ bụrụ otu ma nweta nha nha electrochemical. Mgbe a na-agụ ihe, e kwesịrị ịkwụsị mkpali ahụ ma hapụ ya ka ọ guzoro ruo oge ụfọdụ ka o wee kwe ka ọgụgụ ahụ kwụsie ike.
⑸ Mgbe ị na-atụ ihe, buru ụzọ kpochapụ electrodes abụọ ahụ nke ọma na mmiri, wee kpochaa ya na ihe nlele mmiri ahụ, wee gbanye electrodes n'ime obere beaker nke nwere ihe nlele mmiri ahụ, jiri aka gị maa mma nke ọma iji mee ka nlele mmiri dị otu, wee dekọọ ya. Uru pH mgbe ọgụgụ ahụ kwụsiri ike.
Oge nzipu: Ọktoba 26-2023
