1. Isidingo sokugcina amanzi
Zonke izinhlobo zezisekelo ezidinga udaka lokwakha zinezinga elithile lokumuncwa kwamanzi. Ngemva kokuba ungqimba lwesisekelo lumunce amanzi odaka, ukwakheka kodaka kuzowohloka, futhi ezimweni ezimbi kakhulu, izinto eziqinisa udaka odaka ngeke zigcwaliswe ngamanzi ngokugcwele, okuholela emandleni aphansi, ikakhulukazi amandla okuxhumana phakathi kodaka oluqinile kanye nongqimba lwesisekelo, okubangela ukuthi udaka luqhekeke futhi luwe. Uma udaka lokuplasta lusebenza kahle ekugcineni amanzi, alukwazi nje kuphela ukuthuthukisa ukusebenza kokwakhiwa kodaka, kodwa futhi lwenze amanzi odaka kube nzima ukumuncwa ungqimba lwesisekelo futhi luqinisekise ukumuncwa okwanele kwesamente.
2. Izinkinga ngezindlela zokugcina amanzi zendabuko
Isixazululo sendabuko ukunisela isisekelo, kodwa akunakwenzeka ukuqinisekisa ukuthi isisekelo simanziswe ngokulinganayo. Umgomo ofanele wokunisela isisekelo ngodaka lukasimende ukuthi umkhiqizo wokunisela usimende umunce amanzi kanye nesisekelo, ungene esisekelweni, futhi wakhe "uxhumano oluyisihluthulelo" olusebenzayo nesisekelo, ukuze kufezwe amandla esibopho adingekayo. Ukunisela ngqo ebusweni besisekelo kuzobangela ukuhlakazeka okukhulu ekumuncekeni kwamanzi kwesisekelo ngenxa yokwehluka kwezinga lokushisa, isikhathi sokunisela, kanye nokufana kokunisela. Isisekelo sinokumunca kwamanzi okuncane futhi sizoqhubeka nokumunca amanzi kudaka. Ngaphambi kokuba kuqhubeke ukumunca kukasimende, amanzi ayamuncwa, okuthinta ukumunca kukasimende kanye nokungena kwemikhiqizo yokumunca amanzi ku-matrix; isisekelo sinokumunca kwamanzi okukhulu, futhi amanzi kudaka agelezela esisekelweni. Ijubane lokufuduka eliphakathi lihamba kancane, futhi ngisho nengqimba ecebile ngamanzi yakhiwa phakathi kodaka kanye ne-matrix, okuthinta namandla esibopho. Ngakho-ke, ukusebenzisa indlela evamile yokunisela eyisisekelo ngeke nje kwehluleke ukuxazulula ngempumelelo inkinga yokumuncwa kwamanzi amaningi esisekelo sodonga, kodwa kuzothinta amandla okubopha phakathi kwe-mortar nesisekelo, okuholela ekuqhekekeni nasekuqhekekeni.
3. Izidingo zama-mortar ahlukene okugcina amanzi
Izinga lokugcina amanzi elihlosiwe lokufaka iplasta emikhiqizweni kadoti esetshenziswa endaweni ethile nasezindaweni ezinezimo ezifanayo zokushisa nomswakama liphakanyisiwe ngezansi.
①Udaka lokuplasta olumunca amanzi amaningi
Izisekelo zokumunca amanzi eziningi ezimelelwa ukhonkolo ofakwe emoyeni, okuhlanganisa amabhodi ahlukahlukene okuhlukanisa alula, amabhlogo, njll., zinezici zokumunca amanzi amaningi kanye nobude besikhathi eside. Udaka lokuplasta olusetshenziswa kulolu hlobo lwesendlalelo sesisekelo kufanele lube nesilinganiso sokugcina amanzi esingaphansi kwama-88%.
②Udaka lokuplasta olungenamanzi amaningi
Izisekelo zokumunca amanzi kancane ezimelelwa ukhonkolo ofakwe endaweni, okuhlanganisa namabhodi e-polystyrene okuvikela udonga lwangaphandle, njll., zinokumunca kwamanzi okuncane kakhulu. Udaka lokuplasta olusetshenziswa kulezi zisekelo kufanele lube nesilinganiso sokugcina amanzi esingaphansi kwama-88%.
③Udaka olufakwe ungqimba oluncane
Ukuplasta okunezingqimba ezincane kubhekisela ekwakhiweni kokuplasta okunobukhulu bengqimba yokuplasta obuphakathi kuka-3 no-8 mm. Lolu hlobo lokwakhiwa kokuplasta kulula ukulahlekelwa umswakama ngenxa yengqimba yokuplasta encane, okuthinta ukusebenza kahle namandla. Ku-mortar esetshenziswa kulolu hlobo lokuplasta, izinga layo lokugcina amanzi alingaphansi kuka-99%.
④Udaka lokuplasta olunezingqimba ezinkulu
Ukuplasta ngezingqimba ezijiyile kubhekisela ekwakhiweni kokuplasta lapho ubukhulu besendlalelo esisodwa sokuplasta buphakathi kuka-8mm no-20mm. Lolu hlobo lokwakhiwa kokuplasta akulula ukulahlekelwa amanzi ngenxa yesendlalelo sokuplasta esijiyile, ngakho-ke izinga lokugcina amanzi kodaka lokuplasta akufanele libe ngaphansi kuka-88%.
⑤I-putty engangeni manzi
I-putty engangeni manzi isetshenziswa njengento yokuplasta encane kakhulu, kanti ubukhulu bokwakha obujwayelekile buphakathi kuka-1 no-2mm. Izinto ezinjalo zidinga izakhiwo zokugcina amanzi eziphezulu kakhulu ukuqinisekisa ukusebenza kwazo kanye namandla okubopha. Ngezinto zokufaka i-putty, izinga layo lokugcina amanzi akufanele libe ngaphansi kuka-99%, kanti izinga lokugcina amanzi le-putty ezindongeni zangaphandle kufanele libe likhulu kunele-putty ezindongeni zangaphakathi.
4. Izinhlobo zezinto zokugcina amanzi
I-ether ye-cellulose
1) I-Methyl cellulose ether (MC)
2) I-Hydroxypropyl Methyl Cellulose Ether (HPMC)
3) I-Hydroxyethyl cellulose ether (HEC)
4) I-Carboxymethyl cellulose ether (CMC)
5) I-Hydroxyethyl Methyl Cellulose Ether (HEMC)
I-ether yesitashi
1) I-ether yesitashi esiguquliwe
2) I-ether ye-Guar
Isithambisi esiguquliwe sokugcina amanzi amaminerali (i-montmorillonite, i-bentonite, njll.)
Okwesihlanu, okulandelayo kugxile ekusebenzeni kwezinto ezahlukahlukene
1. I-ether ye-cellulose
1.1 Ukubuka konke kwe-Cellulose Ether
I-Cellulose ether yigama elijwayelekile lochungechunge lwemikhiqizo eyakhiwe ukusabela kwe-alkali cellulose kanye ne-etherification agent ngaphansi kwezimo ezithile. Ama-cellulose ether ahlukene atholakala ngoba i-alkali fiber ithathelwa indawo ama-ether ahlukene e-etherification. Ngokwezakhiwo ze-ionization zezinto ezithatha indawo yayo, ama-cellulose ether angahlukaniswa ngezigaba ezimbili: i-ionic, njenge-carboxymethyl cellulose (CMC), kanye ne-nonionic, njenge-methyl cellulose (MC).
Ngokwezinhlobo zezinto ezithatha indawo, ama-ether e-cellulose angahlukaniswa abe ama-monoether, njenge-methyl cellulose ether (MC), kanye nama-ether axubile, njenge-hydroxyethyl carboxymethyl cellulose ether (HECMC). Ngokwezinhlobo ezahlukene zezinyibilikisi ezincibilikayo, ingahlukaniswa ibe izinhlobo ezimbili: ezincibilikayo emanzini kanye nezincibilikayo eziphilayo.
1.2 Izinhlobo eziyinhloko ze-cellulose
I-Carboxymethylcellulose (CMC), izinga elisebenzayo lokufaka esikhundleni: 0.4-1.4; i-etherification agent, i-monooxyacetic acid; i-solvent encibilikisayo, amanzi;
I-Carboxymethyl hydroxyethyl cellulose (CMHEC), izinga elisebenzayo lokufaka esikhundleni: 0.7-1.0; i-etherification agent, i-monooxyacetic acid, i-ethylene oxide; i-solvent encibilikisayo, amanzi;
I-Methylcellulose (MC), izinga elisebenzayo lokufaka esikhundleni: 1.5-2.4; i-etherification agent, i-methyl chloride; i-solvent encibilikisayo, amanzi;
I-Hydroxyethyl cellulose (HEC), izinga elisebenzayo lokufaka esikhundleni: 1.3-3.0; i-etherification agent, i-ethylene oxide; i-solvent encibilikisayo, amanzi;
I-Hydroxyethyl methylcellulose (HEMC), izinga elisebenzayo lokufaka esikhundleni: 1.5-2.0; i-etherification agent, i-ethylene oxide, i-methyl chloride; i-solvent encibilikisayo, amanzi;
I-Hydroxypropyl cellulose (HPC), izinga elisebenzayo lokufaka esikhundleni: 2.5-3.5; i-etherification agent, i-propylene oxide; i-solvent encibilikisayo, amanzi;
I-Hydroxypropyl methylcellulose (HPMC), izinga elisebenzayo lokufaka esikhundleni: 1.5-2.0; i-etherification agent, i-propylene oxide, i-methyl chloride; i-solvent encibilikisayo, amanzi;
I-ethyl cellulose (EC), izinga elisebenzayo lokufaka esikhundleni: 2.3-2.6; i-etherification agent, i-monochloroethane; i-solvent encibilikisayo, i-organic solvent;
I-Ethyl hydroxyethyl cellulose (EHEC), izinga elisebenzayo lokufaka esikhundleni: 2.4-2.8; i-etherification agent, i-monochloroethane, i-ethylene oxide; i-solvent encibilikayo, i-solvent ephilayo;
1.3 Izakhiwo ze-cellulose
1.3.1 I-Methyl cellulose ether (MC)
①I-Methylcellulose iyancibilika emanzini abandayo, futhi kuzoba nzima ukuyincibilika emanzini ashisayo. Isixazululo sayo samanzi sizinzile kakhulu ebangeni le-PH=3-12. Ihambisana kahle nesitashi, i-guar gum, njll. kanye nama-surfactants amaningi. Lapho izinga lokushisa lifinyelela izinga lokushisa le-gelation, kwenzeka i-gelation.
②Ukugcinwa kwamanzi kwe-methylcellulose kuncike enanini layo lokwengeza, i-viscosity, ubuncane bezinhlayiya kanye nezinga lokuncibilika. Ngokuvamile, uma inani lokwengeza likhulu, ubuncane buncane, kanti i-viscosity inkulu, ukugcinwa kwamanzi kuphezulu. Phakathi kwazo, inani lokwengeza linomthelela omkhulu ekugcinweni kwamanzi, futhi i-viscosity ephansi kakhulu ayilingani ngqo nezinga lokugcinwa kwamanzi. Izinga lokuncibilika lincike kakhulu ezingeni lokuguqulwa kobuso bezinhlayiya ze-cellulose kanye nobuncane bezinhlayiya. Phakathi kwama-ether e-cellulose, i-methyl cellulose inezinga eliphezulu lokugcinwa kwamanzi.
③Ukushintsha kwezinga lokushisa kuzothinta kakhulu izinga lokugcina amanzi le-methyl cellulose. Ngokuvamile, uma izinga lokushisa liphakeme, kuba kubi kakhulu ukugcinwa kwamanzi. Uma izinga lokushisa le-mortar lidlula ama-40°C, ukugcinwa kwamanzi kwe-methyl cellulose kuzoba kubi kakhulu, okuzothinta kakhulu ukwakhiwa kwe-mortar.
④ I-Methyl cellulose inomthelela omkhulu ekwakhiweni nasekunamatheleni kwe-mortar. “Ukunamathela” lapha kubhekisela emandleni okunamathela azwakalayo phakathi kwethuluzi lokufaka isicelo somsebenzi kanye ne-substrate yodonga, okungukuthi, ukumelana nokusika kwe-mortar. Ukunamathela kuphakeme, ukumelana nokusika kwe-mortar kukhulu, futhi abasebenzi badinga amandla engeziwe ngesikhathi sokusetshenziswa, futhi ukusebenza kokwakhiwa kwe-mortar kuba kubi. Ukunamathela kwe-Methyl cellulose kusezingeni eliphakathi emikhiqizweni ye-cellulose ether.
1.3.2 I-Hydroxypropyl Methyl Cellulose Ether (HPMC)
I-Hydroxypropyl methylcellulose iwumkhiqizo wefayibha okhiqizwayo kanye nokusetshenziswa kwawo kukhula ngokushesha eminyakeni yamuva.
Kuyi-ether exubile ye-cellulose engeyona i-ionic eyenziwe ngokotini ocwengekile ngemva kokuhlanganiswa kwe-alkali, kusetshenziswa i-propylene oxide kanye ne-methyl chloride njengezinto ezibangela i-etherification, kanye nochungechunge lwezimpendulo. Izinga lokushintshana ngokuvamile liyi-1.5-2.0. Izakhiwo zayo zihlukile ngenxa yezilinganiso ezahlukene zokuqukethwe kwe-methoxyl kanye nokuqukethwe kwe-hydroxypropyl. Okuqukethwe okuphezulu kwe-methoxyl kanye nokuqukethwe okuphansi kwe-hydroxypropyl, ukusebenza kuseduze ne-methyl cellulose; okuqukethwe okuphansi kwe-methoxyl kanye nokuqukethwe okuphezulu kwe-hydroxypropyl, ukusebenza kuseduze ne-hydroxypropyl cellulose.
①I-Hydroxypropyl methylcellulose incibilika kalula emanzini abandayo, futhi kuzoba nzima ukuyincibilika emanzini ashisayo. Kodwa izinga lokushisa layo le-gelation emanzini ashisayo liphakeme kakhulu kunele-methyl cellulose. Ukuncibilika emanzini abandayo nakho kuthuthuke kakhulu uma kuqhathaniswa ne-methyl cellulose.
② Ukuqina kwe-hydroxypropyl methylcellulose kuhlobene nesisindo sayo sama-molecule, futhi uma isisindo sama-molecule siphakeme, kulapho ukuqina kwe-viscosity kuphakama khona. Izinga lokushisa lithinta nokuqina kwayo, njengoba izinga lokushisa likhuphuka, ukuqina kwe-viscosity kwehla. Kodwa ukuqina kwayo akuthinteki kakhulu izinga lokushisa kune-methyl cellulose. Isixazululo sayo sizinzile uma sigcinwe ekushiseni kwegumbi.
③Ukugcinwa kwamanzi kwe-hydroxypropyl methylcellulose kuncike enanini layo lokwengeza, i-viscosity, njll., futhi izinga layo lokugcinwa kwamanzi ngaphansi kwenani elifanayo lokwengeza liphakeme kunele-methyl cellulose.
④I-Hydroxypropyl methylcellulose izinzile ku-asidi kanye ne-alkali, futhi isixazululo sayo samanzi sizinzile kakhulu ku-PH=2-12. I-Caustic soda kanye namanzi e-lime azinawo umthelela omkhulu ekusebenzeni kwayo, kodwa i-alkali ingasheshisa ukuncibilika kwayo futhi ikhuphule kancane i-viscosity yayo. I-Hydroxypropyl methylcellulose izinzile ku-viscosity evamile, kodwa lapho ukuhlushwa kwesisombululo sikasawoti kuphezulu, i-viscosity yesisombululo se-hydroxypropyl methylcellulose ivame ukwanda.
⑤I-hydroxypropyl methylcellulose ingaxutshwa nama-polymer ancibilika emanzini ukuze kwakheke isixazululo esifanayo nesicacile esine-viscosity ephezulu. Njenge-polyvinyl alcohol, i-starch ether, i-vegetable gum, njll.
⑥ I-hydroxypropyl methylcellulose inokumelana okungcono kwama-enzyme kune-methylcellulose, futhi isixazululo sayo cishe asikwazi ukuwohloka ngama-enzyme kune-methylcellulose.
⑦Ukunamathela kwe-hydroxypropyl methylcellulose ekwakhiweni kwe-mortar kuphakeme kunokwe-methylcellulose.
1.3.3 I-Hydroxyethyl cellulose ether (HEC)
Yenziwe ngokotini ocoliwe ophathwe nge-alkali, futhi ixutshwe ne-ethylene oxide njenge-etherification agent lapho kukhona i-acetone. Izinga lokushintshana ngokuvamile lingu-1.5-2.0. Inamandla okushintsha amanzi futhi kulula ukuyimunca umswakama.
①I-Hydroxyethyl cellulose iyancibilika emanzini abandayo, kodwa kunzima ukuyincibilika emanzini ashisayo. Isixazululo sayo sizinzile ekushiseni okuphezulu ngaphandle kokufaka i-gelling. Ingasetshenziswa isikhathi eside ngaphansi kokushisa okuphezulu ku-mortar, kodwa ukugcinwa kwamanzi kwayo kuphansi kune-methyl cellulose.
②I-Hydroxyethyl cellulose izinzile ku-asidi ejwayelekile kanye ne-alkali. I-Alkali ingasheshisa ukuncibilika kwayo futhi ikhuphule kancane i-viscosity yayo. Ukuhlakazeka kwayo emanzini kubi kancane kunokwe-methyl cellulose kanye ne-hydroxypropyl methyl cellulose.
③I-Hydroxyethyl cellulose inamandla amahle okulwa nokuwohloka kwe-mortar, kodwa inesikhathi eside sokulibazisa i-samente.
④Ukusebenza kwe-hydroxyethyl cellulose ekhiqizwa amanye amabhizinisi asekhaya kusobala ukuthi kuphansi kunokwe-methyl cellulose ngenxa yokuqukethwe kwayo kwamanzi amaningi kanye nokuqukethwe komlotha okuphezulu.
1.3.4 I-Carboxymethyl cellulose ether (CMC) yenziwe ngemicu yemvelo (ukotini, i-hemp, njll.) ngemva kokwelashwa nge-alkali, kusetshenziswa i-sodium monochloroacetate njenge-etherification agent, futhi idlula ochungechungeni lwezindlela zokwelapha ukuze kwenziwe i-ionic cellulose ether. Izinga lokushintsha ngokuvamile lingu-0.4-1.4, futhi ukusebenza kwayo kuthinteka kakhulu yizinga lokushintsha.
①I-carboxymethyl cellulose i-hygroscopic kakhulu, futhi izoqukatha inani elikhulu lamanzi uma igcinwa ngaphansi kwezimo ezijwayelekile.
②Isixazululo samanzi se-hydroxymethyl cellulose ngeke sikhiqize ijeli, futhi i-viscosity izoncipha uma izinga lokushisa likhuphuka. Uma izinga lokushisa lidlula ama-℃ angu-50, i-viscosity ayinakuguqulwa.
③ Ukuqina kwayo kuthinteka kakhulu yi-pH. Ngokuvamile, ingasetshenziswa ku-mortar esekelwe ku-gypsum, kodwa hhayi ku-mortar esekelwe kusimende. Uma ine-alkaline kakhulu, ilahlekelwa yi-viscosity.
④ Ukugcinwa kwamanzi kwayo kuphansi kakhulu kune-methyl cellulose. Inomphumela wokulibazisa ku-mortar esekelwe ku-gypsum futhi inciphisa amandla ayo. Kodwa-ke, intengo ye-carboxymethyl cellulose iphansi kakhulu kuneye-methyl cellulose.
2. I-ether yesitashi esiguquliwe
Ama-starch ether avame ukusetshenziswa kuma-mortar aguqulwa kusuka kuma-polymer emvelo amanye ama-polysaccharide. Njengamazambane, ummbila, i-cassava, ubhontshisi we-guar, njll. aguqulwa abe ama-starch ether ahlukahlukene aguquliwe. Ama-starch ether avame ukusetshenziswa kuma-mortar yi-hydroxypropyl starch ether, i-hydroxymethyl starch ether, njll.
Ngokuvamile, ama-starch ether aguqulwe kusuka kumazambane, ummbila, kanye ne-cassava anokugcinwa kwamanzi okuphansi kakhulu kune-cellulose ethers. Ngenxa yezinga layo elihlukile lokuguqulwa, ikhombisa ukuqina okuhlukile kwe-acid kanye ne-alkali. Eminye imikhiqizo ifanele ukusetshenziswa kuma-mortar asekelwe ku-gypsum, kanti eminye ayinakusetshenziswa kuma-mortar asekelwe kusimende. Ukusetshenziswa kwe-starch ether kuma-mortar kusetshenziswa kakhulu njengesithambisi ukuthuthukisa isici sokulwa nokugoba kwe-mortar, ukunciphisa ukunamathela kwe-mortar emanzi, kanye nokwandisa isikhathi sokuvula.
Ama-starch ether avame ukusetshenziswa kanye ne-cellulose, okuholela ezimpahleni ezihambisanayo kanye nezinzuzo zemikhiqizo emibili. Njengoba imikhiqizo ye-starch ether ishibhile kakhulu kune-cellulose ether, ukusetshenziswa kwe-starch ether ku-mortar kuzoletha ukwehla okukhulu kwezindleko ze-mortar formulations.
3. I-Guar gum ether
I-Guar gum ether uhlobo lwe-polysaccharide e-etherified enezakhiwo ezikhethekile, eziguqulwa kusuka kubhontshisi we-guar wemvelo. Ngokuyinhloko ngokusebenzisa ukusabela kwe-etherification phakathi kwe-guar gum namaqembu asebenzayo e-acrylic, kwakheka isakhiwo esiqukethe amaqembu asebenzayo e-2-hydroxypropyl, okuyisakhiwo se-polygalactomannose.
①Uma kuqhathaniswa ne-cellulose ether, i-guar gum ether kulula ukuyincibilikisa emanzini. I-PH ngokuyisisekelo ayinawo umthelela ekusebenzeni kwe-guar gum ether.
②Ngaphansi kwezimo ze-viscosity ephansi kanye nomthamo ophansi, i-guar gum ingathatha indawo ye-cellulose ether ngenani elilinganayo, futhi inokugcinwa kwamanzi okufanayo. Kodwa ukuqina, ukumelana nokuwa, i-thixotropy nokunye kusobala ukuthi kuthuthukisiwe.
③Ngaphansi kwezimo ze-viscosity ephezulu kanye nomthamo omkhulu, i-guar gum ayikwazi ukuthatha indawo ye-cellulose ether, futhi ukusetshenziswa okuxubile kwalokhu okubili kuzokhiqiza ukusebenza okungcono.
④Ukusetshenziswa kwe-guar gum ku-mota eyenziwe nge-gypsum kunganciphisa kakhulu ukunamathela ngesikhathi sokwakha futhi kwenze ukwakhiwa kube bushelelezi. Akunawo umthelela omubi esikhathini sokusetha kanye namandla e-mota eyenziwe nge-gypsum.
⑤ Uma i-guar gum isetshenziswa ku-masonry esekelwe kusimende kanye nodaka lokuplasta, ingathatha indawo ye-cellulose ether ngenani elilinganayo, futhi inikeze udaka ukumelana okungcono kokugoba, i-thixotropy kanye nokushelela kokwakhiwa.
⑥Esigqumeni esinobuthi obukhulu kanye nokuqukethwe okuphezulu kwe-ejenti yokugcina amanzi, i-guar gum kanye ne-cellulose ether kuzosebenzisana ukuze kutholakale imiphumela emihle kakhulu.
⑦ I-guar gum ingasetshenziswa futhi emikhiqizweni efana nezinamathiselo zamathayili, izinto ezizilinganisayo ezigayiwe, i-putty engangeni manzi, kanye nodaka lwe-polymer lokuvikela udonga.
4. Isithambisi sokugcina amanzi amaminerali esiguquliwe
Isithambisi sokugcina amanzi esenziwe ngamaminerali emvelo ngokuguqulwa nokuhlanganiswa sisetshenziswe eShayina. Amaminerali ayinhloko asetshenziselwa ukulungiselela izithambisi zokugcina amanzi yilawa: i-sepiolite, i-bentonite, i-montmorillonite, i-kaolin, njll. Lawa maminerali anezakhiwo ezithile zokugcina amanzi nokuqina ngokuguqulwa njengezinto zokuhlanganisa. Lolu hlobo lwesithambisi sokugcina amanzi esisetshenziswa ku-mortar lunezici ezilandelayo.
① Kungathuthukisa kakhulu ukusebenza kwe-mortar evamile, futhi kuxazulule izinkinga zokungasebenzi kahle kwe-mortar yesamente, amandla aphansi e-mortar exubile, kanye nokumelana namanzi okungekuhle.
② Imikhiqizo yodaka enamazinga ahlukene amandla ezakhiweni zezimboni nezomphakathi ingenziwa.
③Izindleko zezinto zokwakha ziphansi.
④ Ukugcinwa kwamanzi kuphansi kunezinto zokugcina amanzi eziphilayo, futhi inani lokuncishiswa okomile kodaka olulungisiwe likhulu kakhulu, futhi ukuhlangana kuyancipha.
Isikhathi sokuthunyelwe: Mashi-03-2023