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He hoʻoweliweli koʻikoʻi nā ʻino lepo i nā ʻāina he nui a puni ka honua ma muli o ko lākou hopena luku i ka mahiʻai, ke olakino kanaka, nā pūnaewele halihali a me nā ʻoihana. ʻO ka hopena, ua manaʻo ʻia ka ʻino ʻana o ka makani he pilikia honua. ʻO kekahi o nā ala e pili ana i ke kaiapuni e kāohi ai i ka ʻino ʻana o ka makani ʻo ia ka hoʻohana ʻana i ka microbial induced carbonate precipitation (MICP). Eia nō naʻe, ʻaʻole kūpono nā huahana o ka urea-based degradation-based MICP, e like me ka ammonia, ke hana ʻia i nā nui he nui. Hōʻike kēia haʻawina i ʻelua mau ʻano o ka calcium formate bacteria no ka hoʻohaʻahaʻa ʻana o MICP me ka ʻole o ka hana ʻana i ka urea a hoʻohālikelike piha i kā lākou hana me ʻelua mau ʻano o ka calcium acetate bacteria non-ammonia-producing. ʻO nā bacteria i manaʻo ʻia ʻo Bacillus subtilis a me Bacillus amyloliquefaciens. ʻO ka mea mua, ua hoʻoholo ʻia nā waiwai i hoʻonui ʻia o nā mea e kaohi ana i ka hoʻokumu ʻana o CaCO3. A laila ua hana ʻia nā hoʻokolohua tunnel makani ma nā laʻana one one i mālama ʻia me nā ʻano i hoʻonui ʻia, a ua ana ʻia ke kūʻē ʻana o ka makani erosion, ka wikiwiki o ka stripping threshold, a me ke kūʻē ʻana o ke one bombardment. Ua loiloi ʻia nā allomorphs Calcium carbonate (CaCO3) me ka hoʻohana ʻana i ka microscopy optical, scanning electron microscopy (SEM), a me ka nānā ʻana o ka diffraction X-ray. ʻOi aku ka maikaʻi o ka hana ʻana o nā ʻano hana i hoʻokumu ʻia i ka calcium formate ma mua o nā ʻano hana i hoʻokumu ʻia i ka acetate ma ke ʻano o ka hoʻokumu ʻana o ka calcium carbonate. Eia kekahi, ua hana ʻo B. subtilis i ka calcium carbonate ma mua o B. amyloliquefaciens. Ua hōʻike maopopo nā micrographs SEM i ka nakinaki ʻana a me ke kaha ʻana o nā bacteria hana a me nā bacteria hana ʻole ma ka calcium carbonate i hoʻokumu ʻia e ka sedimentation. Ua hōʻemi nui nā ʻano hana āpau i ka ʻino ʻana o ka makani.
Ua ʻike ʻia ka ʻino ʻana o ka makani no ka manawa lōʻihi ma ke ʻano he pilikia nui e kū nei i nā wahi maloʻo a me nā wahi maloʻo hapa e like me ke komohana hema o ʻAmelika Hui Pū ʻIa, ke komohana o Kina, ʻApelika Sahara, a me ka hapa nui o ka Hikina Waena1. ʻO ka ua haʻahaʻa ma nā aniau maloʻo a me nā aniau maloʻo loa ua hoʻololi i nā ʻāpana nui o kēia mau wahi i nā wao nahele, nā puʻu one, a me nā ʻāina i mahi ʻole ʻia. ʻO ka hoʻomau ʻana o ka ʻino ʻana o ka makani e hoʻoweliweli i ke kaiapuni i nā ʻoihana e like me nā pūnaewele halihali, ka ʻāina mahiʻai, a me ka ʻāina ʻoihana, e alakaʻi ana i nā kūlana noho maikaʻi ʻole a me nā kumukūʻai kiʻekiʻe o ka hoʻomohala kūlanakauhale ma kēia mau wahi2,3,4. ʻO ka mea nui, ʻaʻole wale ka hopena o ka ʻino ʻana o ka makani i kahi e hana ʻia ai, akā ke kumu pū kekahi i nā pilikia olakino a me ka hoʻokele waiwai ma nā kaiāulu mamao i ka wā e lawe ana i nā ʻāpana e ka makani i nā wahi mamao loa mai ke kumu5,6.
ʻO ka kaohi ʻana i ka makani he pilikia honua. Hoʻohana ʻia nā ʻano hana like ʻole o ka hoʻopaʻa ʻana i ka lepo e kaohi i ka makani. ʻO kēia mau ʻano hana e komo pū me nā mea e like me ka noi wai7, nā mulches aila8, biopolymers5, ka microbial induced carbonate precipitation (MICP)9,10,11,12 a me ka enzyme induced carbonate precipitation (EICP)1. ʻO ka hoʻomaʻū ʻana i ka lepo kahi ʻano maʻamau o ka hoʻopau ʻana i ka lepo ma ke kula. Eia nō naʻe, ʻo kona mahu wikiwiki e hoʻolilo i kēia ʻano hana i palena iki ka pono ma nā wahi maloʻo a me nā wahi semi-arid1. Hoʻonui ka hoʻopili ʻana i nā hui mulching aila i ka cohesion one a me ka friction interparticle. Hoʻopaʻa ko lākou waiwai cohesive i nā hua one; akā naʻe, hoʻopilikia pū nā mulches aila i nā pilikia ʻē aʻe; hoʻonui ko lākou kala ʻeleʻele i ka omo ʻana o ka wela a alakaʻi i ka make ʻana o nā mea kanu a me nā microorganism. Hiki i ko lākou ʻala a me ka uahi ke hoʻoulu i nā pilikia hanu, a ʻo ka mea nui loa, ʻo ko lākou kumukūʻai kiʻekiʻe kekahi mea keakea. ʻO Biopolymers kekahi o nā ʻano hana eco-friendly i manaʻo ʻia no ka hōʻemi ʻana i ka makani; ua unuhi ʻia lākou mai nā kumu kūlohelohe e like me nā mea kanu, nā holoholona a me nā bacteria. ʻO Xanthan gum, guar gum, chitosan a me gellan gum nā biopolymers i hoʻohana pinepine ʻia i nā noi ʻenekinia5. Eia nō naʻe, hiki i nā biopolymers wai-hoʻoheheʻe ʻia ke nalowale ka ikaika a hoʻokuʻu i waho o ka lepo ke hōʻike ʻia i ka wai13,14. Ua hōʻike ʻia ʻo EICP he ʻano hana hoʻopau lepo kūpono no nā ʻano hana like ʻole me nā alanui i hoʻopaʻa ʻole ʻia, nā loko wai a me nā kahua kūkulu. ʻOiai he mea hoʻoikaika kona mau hopena, pono e noʻonoʻo ʻia kekahi mau hemahema, e like me ke kumukūʻai a me ka nele o nā wahi nucleation (kahi e hoʻolalelale ai i ka hoʻokumu ʻana a me ka ua ʻana o nā kristal CaCO315,16).
Ua wehewehe mua ʻia ʻo MICP i ka hopena o ke kenekulia 19 e Murray lāua ʻo Irwin (1890) a me Steinmann (1901) i kā lāua noiʻi ʻana i ka hoʻohaʻahaʻa ʻana o ka urea e nā microorganism moana17. ʻO MICP kahi hana olaola kūlohelohe e pili ana i nā ʻano hana microbial a me nā kaʻina hana kemika kahi e hoʻoulu ʻia ai ka calcium carbonate e ka hopena o nā ion carbonate mai nā metabolites microbial me nā ion calcium i ke kaiapuni18,19. ʻO MICP e pili ana i ka pōʻaiapuni nitrogen urea-degrading (urea-degrading MICP) ʻo ia ke ʻano maʻamau o ka microbial-induced carbonate precipitation, kahi e hoʻoulu ai ka urease i hana ʻia e ka bacteria i ka hydrolysis o urea20,21,22,23,24,25,26,27 penei:
Ma MICP e pili ana i ke kaʻina hana kalapona o ka hoʻomake ʻana o ka paʻakai organik (MICP me ka ʻole o ke ʻano hoʻohaʻahaʻa urea), hoʻohana nā bacteria heterotrophic i nā paʻakai organik e like me ka acetate, lactate, citrate, succinate, oxalate, malate a me glyoxylate ma ke ʻano he kumu ikehu e hana i nā minelala carbonate28. I ke alo o ka calcium lactate ma ke ʻano he kumu kalapona a me nā ion calcium, ua hōʻike ʻia ka hopena kemika o ka hoʻokumu ʻana o ka calcium carbonate ma ka hoohalike (5).
I ke kaʻina hana MICP, hāʻawi nā pūnaewele bacteria i nā wahi nucleation i mea nui loa no ka hoʻoheheʻe ʻia ʻana o ka calcium carbonate; ua hoʻopiʻi maikaʻi ʻole ʻia ka ʻili o nā cell bacteria a hiki ke hana ma ke ʻano he adsorbent no nā cations divalent e like me nā ions calcium. Ma ka adsorbing calcium ions ma luna o nā cell bacteria, i ka wā e lawa ai ka nui o ka ion carbonate, hana nā cations calcium a me nā anions carbonate a hoʻoheheʻe ʻia ka calcium carbonate ma luna o ka ʻili bacteria29,30. Hiki ke hōʻuluʻulu ʻia ke kaʻina hana penei31,32:
Hiki ke hoʻokaʻawale ʻia nā kristal calcium carbonate i hana ʻia i loko o ka biogenerated i ʻekolu ʻano: calcite, vaterite, a me aragonite. I waena o lākou, ʻo calcite a me vaterite nā allomorph calcium carbonate i hoʻoulu ʻia e ka bacteria maʻamau33,34. ʻO Calcite ka allomorph calcium carbonate paʻa loa35. ʻOiai ua hōʻike ʻia ʻo vaterite he metastable, hoʻololi hope ia i calcite36,37. ʻO Vaterite ka mea paʻa loa o kēia mau kristal. He kristal hexagonal ia i ʻoi aku ka maikaʻi o ka hoʻopiha ʻana i nā pore ma mua o nā kristal calcium carbonate ʻē aʻe ma muli o kona nui nui38. Hiki i nā MICP i hoʻohaʻahaʻa ʻia e ka urea a me ka urea-undegraded ke alakaʻi i ka ua o ka vaterite13,39,40,41.
ʻOiai ua hōʻike ʻo MICP i ka hiki ke hoʻohiki i ka hoʻopaʻa ʻana i nā lepo pilikia a me nā lepo i hiki ke hoʻopilikia ʻia e ka makani42,43,44,45,46,47,48, ʻo kekahi o nā huahana o ka urea hydrolysis ʻo ia ka ammonia, hiki ke hoʻoulu i nā pilikia olakino liʻiliʻi a koʻikoʻi ma muli o ka pae o ka hōʻike49. ʻO kēia hopena ʻaoʻao e hoʻopaʻapaʻa ai ka hoʻohana ʻana i kēia ʻenehana kikoʻī, ʻoiai ke pono e mālama ʻia nā wahi nui, e like me ka hoʻopau ʻana i ka lepo. Eia kekahi, ʻaʻole hiki ke hoʻomanawanui i ke ʻala o ka ammonia ke hana ʻia ke kaʻina hana ma nā helu noi kiʻekiʻe a me nā nui nui, kahi e hoʻopilikia ai i kona hiki ke hoʻohana pono. ʻOiai ua hōʻike ʻia nā haʻawina hou e hiki ke hoʻemi ʻia nā ion ammonium ma ka hoʻololi ʻana iā lākou i nā huahana ʻē aʻe e like me struvite, ʻaʻole hoʻopau loa kēia mau ʻano ion ammonium50. No laila, aia nō ka pono e ʻimi i nā hopena ʻē aʻe ʻaʻole e hana i nā ion ammonium. ʻO ka hoʻohana ʻana i nā ala hoʻohaʻahaʻa non-urea no MICP hiki ke hāʻawi i kahi hopena hiki ke ʻimi maikaʻi ʻole ʻia ma ke ʻano o ka hoʻēmi ʻana i ka makani. Fattahi et al. ua noiʻi ʻia ka hoʻohaʻahaʻa ʻana o ka urea-free MICP me ka hoʻohana ʻana i ka calcium acetate a me Bacillus megaterium41, ʻoiai ʻo Mohebbi et al. ua hoʻohana i ka calcium acetate a me Bacillus amyloliquefaciens9. Eia naʻe, ʻaʻole i hoʻohālikelike ʻia kā lākou noiʻi me nā kumu calcium ʻē aʻe a me nā bacteria heterotrophic i hiki ke hoʻomaikaʻi hope i ke kūʻē ʻana i ka makani. Aia kekahi nele o nā palapala e hoʻohālikelike ana i nā ala hoʻohaʻahaʻa ʻole urea me nā ala hoʻohaʻahaʻa urea i ka hoʻēmi ʻana i ka makani.
Eia kekahi, ua hana ʻia ka hapa nui o nā haʻawina e pili ana i ka ʻino ʻana o ka makani a me ka kaohi ʻana i ka lepo ma nā ʻano lepo me nā ʻili pālahalaha.1,51,52,53 Eia nō naʻe, ʻaʻole i maʻamau nā ʻili pālahalaha ma ke ʻano ma mua o nā puʻu a me nā lua. ʻO ia ke kumu he hiʻohiʻona ʻāina maʻamau nā puʻu one ma nā wahi wao nahele.
I mea e lanakila ai i nā hemahema i ʻōlelo ʻia ma luna, ua manaʻo kēia haʻawina e hoʻolauna i kahi hui hou o nā mea hana bacteria ʻaʻole ammonia. No kēia kumu, ua noʻonoʻo mākou i nā ala MICP ʻaʻole urea e hoʻohaʻahaʻa. Ua noiʻi ʻia ka pono o ʻelua mau kumu calcium (calcium formate a me calcium acetate). I ka ʻike maikaʻi loa o nā mea kākau, ʻaʻole i noiʻi ʻia ka hoʻoheheʻe ʻana o ka carbonate me ka hoʻohana ʻana i ʻelua mau hui kumu calcium a me nā bacteria (ʻo ia hoʻi ka calcium formate-Bacillus subtilis a me ka calcium formate-Bacillus amyloliquefaciens) i nā haʻawina mua. Ua hoʻokumu ʻia ke koho ʻana o kēia mau bacteria ma nā enzymes a lākou e hana ai e hoʻoulu ai i ka oxidation o ka calcium formate a me ka calcium acetate e hana i ka microbial carbonate precipitation. Ua hoʻolālā mākou i kahi haʻawina hoʻokolohua piha e ʻike i nā mea kūpono e like me ka pH, nā ʻano bacteria a me nā kumu calcium a me ko lākou mau ʻano, ka lakio o ka bacteria i ka hopena kumu calcium a me ka manawa hoʻōla. ʻO ka mea hope loa, ua noiʻi ʻia ka pono o kēia hoʻonohonoho o nā mea bacteria i ka kāohi ʻana i ka ʻino ʻana o ka makani ma o ka hoʻopulapula calcium carbonate ma o ka hana ʻana i kahi moʻo o nā hoʻokolohua tunnel makani ma nā puʻu one e hoʻoholo ai i ka nui o ka ʻino ʻana o ka makani, ka wikiwiki o ka breakaway a me ke kū'ē ʻana o ka makani i ke one, a me nā ana penetrometer a me nā haʻawina microstructural (e like me ka nānā ʻana o X-ray diffraction (XRD) a me ka scanning electron microscopy (SEM)).
Pono ka hana ʻana o ka calcium carbonate i nā ion calcium a me nā ion carbonate. Hiki ke loaʻa nā ion calcium mai nā kumu calcium like ʻole e like me ka calcium chloride, calcium hydroxide, a me ka pauka waiū skim54,55. Hiki ke hana ʻia nā ion carbonate e nā ʻano microbial like ʻole e like me ka urea hydrolysis a me ka oxidation aerobic a anaerobic paha o nā mea organik56. Ma kēia haʻawina, ua loaʻa nā ion carbonate mai ka hopena oxidation o formate a me acetate. Eia kekahi, ua hoʻohana mākou i nā paʻakai calcium o formate a me acetate e hana i ka calcium carbonate maʻemaʻe, no laila ua loaʻa wale ʻo CO2 a me H2O ma ke ʻano he huahana by-products. Ma kēia kaʻina hana, hoʻokahi wale nō mea e lawelawe ana ma ke ʻano he kumu calcium a me kahi kumu carbonate, a ʻaʻohe ammonia i hana ʻia. ʻO kēia mau ʻano e hana ai i ke kumu calcium a me ke ʻano hana carbonate a mākou i manaʻo ai he mea hoʻohiki nui.
Ua hōʻike ʻia nā hopena kūlike o ka calcium formate a me ka calcium acetate e hana i ka calcium carbonate ma nā formula (7)-(14). Hōʻike nā formula (7)-(11) e hoʻoheheʻe ʻia ka calcium formate i ka wai e hana i ka waikawa formic a i ʻole formate. No laila, ʻo ka hopena kahi kumu o nā calcium manuahi a me nā ion hydroxide (nā formula 8 a me 9). Ma muli o ka oxidation o ka waikawa formic, ua hoʻololi ʻia nā ʻātoma kalapona i loko o ka waikawa formic i kalapona dioxide (formula 10). Hoʻokumu hope ʻia ka calcium carbonate (nā formula 11 a me 12).
Pēlā nō, ua hoʻokumu ʻia ka calcium carbonate mai ka calcium acetate (nā hoʻohālikelike 13–15), koe wale nō ka hoʻokumu ʻia ʻana o ka waikawa acetic a i ʻole ka acetate ma kahi o ka waikawa formic.
Me ka ʻole o nā enzymes, ʻaʻole hiki ke hoʻoheheʻe ʻia ka acetate a me ka formate i ka mahana o ka lumi. Hoʻoulu ka FDH (formate dehydrogenase) a me CoA (coenzyme A) i ka hoʻoheheʻe ʻia ʻana o ka formate a me ka acetate e hana i ke kalapona dioxide, kēlā me kēia (Eqs. 16, 17) 57, 58, 59. Hiki i nā bacteria like ʻole ke hana i kēia mau enzymes, a me nā bacteria heterotrophic, ʻo ia hoʻi ʻo Bacillus subtilis (PTCC #1204 (Persian Type Culture Collection), i ʻike ʻia hoʻi ʻo NCIMB #13061 (International Collection of Bacteria, Yeast, Phage, Plasmids, Plant Seeds and Plant Cell Tissue Cultures)) a me Bacillus amyloliquefaciens (PTCC #1732, NCIMB #12077), i hoʻohana ʻia ma kēia noiʻi. Ua mahi ʻia kēia mau bacteria i loko o kahi medium e loaʻa ana ka peptone ʻiʻo (5 g/L) a me ka ʻiʻo extract (3 g/L), i kapa ʻia ʻo nutrient broth (NBR) (105443 Merck).
No laila, ua hoʻomākaukau ʻia ʻehā mau ʻano hana e hoʻoulu ai i ka hoʻoheheʻe ʻana o ka calcium carbonate me ka hoʻohana ʻana i ʻelua mau kumu calcium a me ʻelua mau bacteria: calcium formate a me Bacillus subtilis (FS), calcium formate a me Bacillus amyloliquefaciens (FA), calcium acetate a me Bacillus subtilis (AS), a me calcium acetate a me Bacillus amyloliquefaciens (AA).
Ma ka ʻāpana mua o ka hoʻolālā hoʻokolohua, ua hana ʻia nā hoʻokolohua e hoʻoholo i ka hui kūpono e hoʻokō ai i ka hana calcium carbonate kiʻekiʻe loa. ʻOiai ua loaʻa i nā hāpana lepo ka calcium carbonate, ua hoʻolālā ʻia kahi hoʻonohonoho o nā hoʻokolohua loiloi mua e ana pololei i ka CaCO3 i hana ʻia e nā hui like ʻole, a ua loiloi ʻia nā hui ʻana o ka medium culture a me nā hopena kumu calcium. No kēlā me kēia hui pū ʻana o ke kumu calcium a me ka hopena bacteria i wehewehe ʻia ma luna (FS, FA, AS, a me AA), ua loaʻa nā kumu hoʻonui (ka nui o ke kumu calcium, ka manawa hoʻōla, ka nui o ka hopena bacteria i ana ʻia e ka optical density o ka hopena (OD), ka ratio o ke kumu calcium i ka hopena bacteria, a me ka pH) a ua hoʻohana ʻia i nā hoʻokolohua one dune wind tunnel i wehewehe ʻia ma nā ʻāpana aʻe.
No kēlā me kēia hui pū ʻana, ua hana ʻia he 150 mau hoʻokolohua e aʻo ai i ka hopena o ka ua ʻana o CaCO3 a loiloi i nā kumu like ʻole, ʻo ia hoʻi ka nui o ke kumu calcium, ka manawa hoʻōla, ka waiwai OD bacteria, ka lakio o ke kumu calcium i ka hopena bacteria a me ka pH i ka wā o ka oxidation aerobic o nā mea organik (Papa 1). Ua koho ʻia ka pae pH no ke kaʻina hana i hoʻonui ʻia ma muli o nā piʻo ulu o Bacillus subtilis a me Bacillus amyloliquefaciens i mea e loaʻa ai ka ulu wikiwiki. Ua wehewehe ʻia kēia me nā kikoʻī hou aku ma ka ʻāpana Hualoaʻa.
Ua hoʻohana ʻia nā ʻanuʻu ma lalo nei e hoʻomākaukau i nā laʻana no ka pae hoʻonui. Ua hoʻomākaukau mua ʻia ka hopena MICP ma ka hoʻoponopono ʻana i ka pH mua o ka medium moʻomeheu a laila autoclaved ma 121 °C no 15 min. A laila ua hoʻokomo ʻia ke ʻano i loko o kahi kahe ea laminar a mālama ʻia i loko o kahi incubator lulu ma 30 °C a me 180 rpm. I ka hiki ʻana o ka OD o ka bacteria i ka pae i makemake ʻia, ua hui pū ʻia me ka hopena kumu calcium ma ka hapa i makemake ʻia (Kiʻi 1a). Ua ʻae ʻia ka hopena MICP e hana a paʻa i loko o kahi incubator lulu ma 220 rpm a me 30 °C no ka manawa i hiki ai i ka waiwai i manaʻo ʻia. Ua hoʻokaʻawale ʻia ka CaCO3 i hoʻoheheʻe ʻia ma hope o ka centrifugation ma 6000 g no 5 min a laila hoʻomaloʻo ʻia ma 40 °C e hoʻomākaukau i nā laʻana no ka hoʻāʻo calcimeter (Kiʻi 1b). A laila ua ana ʻia ka ua ʻana o CaCO3 me ka hoʻohana ʻana i kahi calcimeter Bernard, kahi e hana ai ka pauka CaCO3 me 1.0 N HCl (ASTM-D4373-02) e hana i ka CO2, a ʻo ka nui o kēia kinoea he ana ia o ka ʻike CaCO3 (Kiʻi 1c). No ka hoʻololi ʻana i ka nui o CO2 i ka ʻike CaCO3, ua hana ʻia kahi piʻo calibration ma ka holoi ʻana i ka pauka CaCO3 maʻemaʻe me 1 N HCl a me ke kaha kiʻi ʻana iā ia e kūʻē i ka CO2 i ulu. Ua noiʻi ʻia ke ʻano a me ka maʻemaʻe o ka pauka CaCO3 i hoʻoulu ʻia me ka hoʻohana ʻana i ka SEM imaging a me ka loiloi XRD. Ua hoʻohana ʻia kahi microscope optical me ka hoʻonui ʻana o 1000 e aʻo i ka hoʻokumu ʻia ʻana o ka calcium carbonate a puni ka bacteria, ke ʻano o ka calcium carbonate i hoʻokumu ʻia, a me ka hana o ka bacteria.
He ʻāina kaulana ʻo Dejegh Basin i ʻino nui ʻia ma ke komohana hema o Fars Province o Iran, a ua hōʻiliʻili nā mea noiʻi i nā laʻana lepo i ʻino ʻia e ka makani mai ia wahi. Ua lawe ʻia nā laʻana mai ka ʻili lepo no ke aʻo ʻana. Ua hōʻike nā hoʻāʻo hōʻailona ma nā laʻana lepo he lepo one maikaʻi ʻole ka lepo me ka silt a ua hoʻokaʻawale ʻia ʻo ia he SP-SM e like me ka Unified Soil Classification System (USC) (Kiʻi 2a). Ua hōʻike ka loiloi XRD ua haku nui ʻia ka lepo Dejegh me ka calcite a me ka quartz (Kiʻi 2b). Eia kekahi, ua hōʻike ka loiloi EDX aia kekahi mau mea ʻē aʻe e like me Al, K, a me Fe i nā ʻāpana liʻiliʻi.
No ka hoʻomākaukau ʻana i nā one one keʻena hoʻokolohua no ka hoʻāʻo ʻana i ka ʻino o ka makani, ua kuʻi ʻia ka lepo mai ke kiʻekiʻe o 170 mm ma o kahi funnel 10 mm ke anawaena a hiki i kahi ʻili paʻa, e hopena ana i kahi one maʻamau he 60 mm ke kiʻekiʻe a me 210 mm ke anawaena. Ma ke ʻano, ua hoʻokumu ʻia nā one one haʻahaʻa loa e nā kaʻina hana aeolian. Pēlā nō, ʻo ka laʻana i hoʻomākaukau ʻia me ka hoʻohana ʻana i ke kaʻina hana ma luna nei he haʻahaʻa loa ka nui, γ = 14.14 kN/m³, e hana ana i kahi cone one i waiho ʻia ma luna o kahi ʻili ākea me kahi kihi hoʻomaha o kahi o 29.7°.
Ua pīpī ʻia ka hopena MICP kūpono loa i loaʻa ma ka ʻāpana ma mua ma luna o ka pali one ma nā helu noi o 1, 2 a me 3 lm-2 a laila ua mālama ʻia nā laʻana i loko o kahi incubator ma 30 °C (Kiʻi 3) no 9 mau lā (ʻo ia hoʻi ka manawa hoʻōla kūpono loa) a laila lawe ʻia i waho no ka hoʻāʻo ʻana i ka tunnel makani.
No kēlā me kēia lāʻau lapaʻau, ua hoʻomākaukau ʻia ʻehā mau ʻāpana, hoʻokahi no ke ana ʻana i ka nui o ka calcium carbonate a me ka ikaika o ka ʻili me ka hoʻohana ʻana i ka penetrometer, a ʻo nā ʻāpana ʻekolu i koe ua hoʻohana ʻia no nā hoʻāʻo erosion ma ʻekolu mau wikiwiki like ʻole. I loko o nā hoʻāʻo tunnel makani, ua hoʻoholo ʻia ka nui o ka erosion ma nā wikiwiki makani like ʻole, a laila ua hoʻoholo ʻia ka wikiwiki breakaway paepae no kēlā me kēia ʻāpana lapaʻau me ka hoʻohana ʻana i kahi kiʻi o ka nui o ka erosion e kūʻē i ka wikiwiki o ka makani. Ma waho aʻe o nā hoʻāʻo erosion makani, ua hoʻokau ʻia nā ʻāpana i mālama ʻia i ka hoʻouka kaua one (ʻo ia hoʻi, nā hoʻokolohua lele). Ua hoʻomākaukau ʻia ʻelua mau ʻāpana hou no kēia kumu ma nā helu noi o 2 a me 3 L m−2. Ua mau ka hoʻāʻo hoʻouka kaua one he 15 min me ka flux o 120 gm−1, aia i loko o ka pae o nā waiwai i koho ʻia ma nā haʻawina mua60,61,62. ʻO ka mamao ākea ma waena o ka nozzle abrasive a me ke kumu one he 800 mm, aia ma 100 mm ma luna o ka lalo o ke tunnel. Ua hoʻonohonoho ʻia kēia kūlana i hāʻule ai nā ʻāpana one lele a pau ma luna o ka one.
Ua mālama ʻia ka hoʻāʻo ʻana o ke ana makani i loko o kahi ana makani hāmama me ka lōʻihi o 8 m, ka laulā o 0.4 m a me ke kiʻekiʻe o 1 m (Kiʻi 4a). Hana ʻia ke ana makani me nā pepa kila galvanized a hiki ke hoʻoulu i ka wikiwiki o ka makani a hiki i ka 25 m/s. Eia kekahi, hoʻohana ʻia kahi mea hoʻololi alapine e hoʻoponopono i ka alapine peʻahi a hoʻonui mālie i ke alapine e loaʻa ai ka wikiwiki o ka makani i manaʻo ʻia. Hōʻike ka Kiʻi 4b i ke kiʻikuhi schematic o nā puʻu one i hoʻopau ʻia e ka makani a me ke ʻano o ka wikiwiki o ka makani i ana ʻia i loko o ke ana makani.
ʻO ka mea hope loa, no ka hoʻohālikelike ʻana i nā hopena o ka hoʻohālikelike MICP non-urealytic i hāpai ʻia ma kēia haʻawina me nā hopena o ka hoʻāʻo hoʻomalu urealytic MICP, ua hoʻomākaukau ʻia a mālama ʻia nā laʻana dune me kahi hopena olaola e loaʻa ana ka urea, calcium chloride a me Sporosarcina pasteurii (ʻoiai he hiki koʻikoʻi ko Sporosarcina pasteurii ke hana i ka urease63). ʻO ka nui o ka optical o ka hopena bacteria he 1.5, a ʻo nā ʻano o ka urea a me ka calcium chloride he 1 M (i koho ʻia ma muli o nā waiwai i ʻōlelo ʻia ma nā haʻawina mua36,64,65). ʻO ka medium moʻomeheu he nutrient broth (8 g/L) a me ka urea (20 g/L). Ua pīpī ʻia ka hopena bacteria ma luna o ka ʻili dune a waiho ʻia no 24 mau hola no ka hoʻopili ʻana o ka bacteria. Ma hope o 24 mau hola o ka hoʻopili ʻana, ua pīpī ʻia kahi hopena cementing (calcium chloride a me urea). ʻO ka hoʻāʻo hoʻomalu urealytic MICP ma hope aku nei i kapa ʻia ʻo UMC. Ua loaʻa ka nui o ka calcium carbonate o nā hāpana lepo i mālama ʻia me ka urealytically a me ka non-urealytically ma ka holoi ʻana e like me ke kaʻina hana i hāpai ʻia e Choi et al.66
Hōʻike ka Kiʻi 5 i nā piʻo ulu o Bacillus amyloliquefaciens lāua ʻo Bacillus subtilis i loko o ka medium culture (solution nutrient) me kahi pae pH mua o 5 a 10. E like me ka mea i hōʻike ʻia ma ke kiʻi, ua ulu wikiwiki ʻo Bacillus amyloliquefaciens lāua ʻo Bacillus subtilis ma ka pH 6-8 a me 7-9, kēlā me kēia. No laila, ua lawe ʻia kēia pae pH i ke kahua optimization.
Nā piʻo ulu o (a) Bacillus amyloliquefaciens a me (b) Bacillus subtilis ma nā waiwai pH mua like ʻole o ka medium nutrient.
Hōʻike ka Kiʻi 6 i ka nui o ke kalapona ʻokikene i hana ʻia ma ka limemeter Bernard, kahi e hōʻike ana i ka calcium carbonate i hoʻoheheʻe ʻia (CaCO3). ʻOiai ua paʻa kekahi kumu i kēlā me kēia hui pū ʻana a ua ʻokoʻa nā kumu ʻē aʻe, ua kūlike kēlā me kēia kiko ma kēia mau kiʻi i ka nui loa o ke kalapona ʻokikene i kēlā hoʻonohonoho o nā hoʻokolohua. E like me ka mea i hōʻike ʻia ma ke kiʻi, i ka piʻi ʻana o ka nui o ke kumu calcium, ua piʻi ka hana ʻana o ka calcium carbonate. No laila, pili pololei ka nui o ke kumu calcium i ka hana ʻana o ka calcium carbonate. ʻOiai ua like ke kumu calcium a me ke kumu kalapona (ʻo ia hoʻi, calcium formate a me ka calcium acetate), ʻo ka nui o nā ion calcium i hoʻokuʻu ʻia, ʻoi aku ka nui o ka calcium carbonate i hoʻokumu ʻia (Kiʻi 6a). I nā ʻano hana AS a me AA, ua hoʻomau ka hoʻonui ʻana o ka hana ʻana o ka calcium carbonate me ka hoʻonui ʻana i ka manawa hoʻōla a hiki i ka nui o ka precipitate i aneane ʻole i loli ma hope o 9 mau lā. I ka ʻano hana FA, ua emi ka wikiwiki o ka hoʻokumu ʻana o ka calcium carbonate i ka wā i ʻoi aku ai ka manawa hoʻōla ma mua o 6 mau lā. Ke hoʻohālikelike ʻia me nā ʻano hana ʻē aʻe, ua hōʻike ka ʻano hana FS i kahi wikiwiki haʻahaʻa o ka hoʻokumu ʻana o ka calcium carbonate ma hope o 3 mau lā (Kiʻi 6b). Ma nā ʻano hana FA a me FS, ua loaʻa he 70% a me 87% o ka huina o ka hana calcium carbonate ma hope o ʻekolu lā, ʻoiai ma nā ʻano hana AA a me AS, ʻo kēia hapa he 46% a me 45% wale nō. Hōʻike kēia he kiʻekiʻe ka nui o ka hoʻokumu ʻana o CaCO3 i ka ʻano hana i hoʻokumu ʻia i ka waikawa formic i ka pae mua i hoʻohālikelike ʻia me ka ʻano hana i hoʻokumu ʻia i ka acetate. Eia nō naʻe, lohi ka nui o ka hoʻokumu ʻana me ka hoʻonui ʻana i ka manawa hoʻōla. Hiki ke hoʻoholo ʻia mai ka Kiʻi 6c ʻoiai ma nā ʻano bacteria ma luna o OD1, ʻaʻohe mea nui i ka hoʻokumu ʻana o ka calcium carbonate.
Ka loli ʻana o ka nui o ke CO2 (a me ka nui o ka CaCO3 e pili ana) i ana ʻia e ka calcimeter Bernard ma ke ʻano he hana o (a) ka nui o ke kumu calcium, (b) ka manawa hoʻonohonoho, (c) OD, (d) pH mua, (e) ka lakio o ke kumu calcium i ka hopena bacteria (no kēlā me kēia ʻano hana); a me (f) ka nui loa o ka calcium carbonate i hana ʻia no kēlā me kēia hui pū ʻana o ke kumu calcium a me ka bacteria.
E pili ana i ka hopena o ka pH mua o ka medium, hōʻike ka Kiʻi 6d no FA a me FS, ua hōʻea ka hana ʻana o CaCO3 i kahi waiwai kiʻekiʻe loa ma ka pH 7. Kūlike kēia ʻike me nā haʻawina mua e pili ana i ka paʻa loa o nā enzymes FDH ma ka pH 7-6.7. Eia naʻe, no AA a me AS, ua piʻi ka ua ʻana o CaCO3 i ka wā i ʻoi aku ai ka pH ma mua o 7. Ua hōʻike pū nā haʻawina mua ʻo ka pae pH kūpono no ka hana enzyme CoA mai 8 a 9.2-6.8. Ke noʻonoʻo nei ʻo nā pae pH kūpono no ka hana enzyme CoA a me ka ulu ʻana o B. amyloliquefaciens he (8-9.2) a me (6-8), kēlā me kēia (Kiʻi 5a), manaʻo ʻia ka pH kūpono o ka hoʻohui ʻana o AA he 8, a ua pili nā pae pH ʻelua. Ua hōʻoia ʻia kēia ʻoiaʻiʻo e nā hoʻokolohua, e like me ka mea i hōʻike ʻia ma ke Kiʻi 6d. ʻOiai ʻo ka pH kūpono loa no ka ulu ʻana o B. subtilis he 7-9 (Kiʻi 5b) a ʻo ka pH kūpono loa no ka hana enzyme CoA he 8-9.2, ʻo ka nui o ka CaCO3 precipitation yield e manaʻo ʻia aia ma ka pae pH o 8-9, kahi i hōʻoia ʻia e ka Kiʻi 6d (ʻo ia hoʻi, ʻo ka pH kūpono loa he 9). Hōʻike nā hopena i hōʻike ʻia ma ka Kiʻi 6e ʻo ka lakio kūpono loa o ka hopena kumu calcium i ka hopena bacteria he 1 no nā hopena acetate a me formate. No ka hoʻohālikelike ʻana, ua loiloi ʻia ka hana o nā ʻano hana like ʻole (ʻo ia hoʻi, AA, AS, FA, a me FS) ma muli o ka hana CaCO3 kiʻekiʻe loa ma lalo o nā kūlana like ʻole (ʻo ia hoʻi, ka nui o ke kumu calcium, ka manawa hoʻōla, OD, ka lakio kumu calcium i ka hopena bacteria, a me ka pH mua). Ma waena o nā ʻano hana i aʻo ʻia, ʻo ka ʻano hana FS ka mea i loaʻa ka hana CaCO3 kiʻekiʻe loa, ʻo ia hoʻi ma kahi o ʻekolu manawa o ka ʻano hana AA (Kiʻi 6f). Ua hana ʻia ʻehā mau hoʻokolohua hoʻomalu bacteria-free no nā kumu calcium ʻelua a ʻaʻohe CaCO3 precipitation i ʻike ʻia ma hope o 30 mau lā.
Ua hōʻike nā kiʻi microscopy optical o nā ʻano hana āpau ʻo ka vaterite ka pae nui i hoʻokumu ʻia ai ka calcium carbonate (Kiʻi 7). He poepoe ke ʻano o nā kristal vaterite69,70,71. Ua ʻike ʻia ua hoʻoheheʻe ʻia ka calcium carbonate ma luna o nā cell bacteria no ka mea ua hoʻopiʻi maikaʻi ʻole ʻia ka ʻili o nā cell bacteria a hiki ke hana ma ke ʻano he adsorbent no nā cations divalent. Ke lawe nei i ka formulation FS ma ke ʻano he laʻana ma kēia haʻawina, ma hope o 24 mau hola, ua hoʻomaka ka calcium carbonate e hana ma luna o kekahi mau cell bacteria (Kiʻi 7a), a ma hope o 48 mau hola, ua piʻi nui ka helu o nā cell bacteria i uhi ʻia me ka calcium carbonate. Eia kekahi, e like me ka mea i hōʻike ʻia ma ke Kiʻi 7b, hiki ke ʻike ʻia nā ʻāpana vaterite. ʻO ka hope loa, ma hope o 72 mau hola, ua like ka nui o nā bacteria me he mea lā ua hoʻopaʻa ʻia e nā kristal vaterite, a ua piʻi nui ka helu o nā ʻāpana vaterite (Kiʻi 7c).
Nā nānā ʻana o ka microscopy optical o ka ua ʻana o CaCO3 i nā haku mele FS i ka hala ʻana o ka manawa: (a) 24, (b) 48 a me (c) 72 h.
No ka noiʻi hou ʻana i ke ʻano o ka pae i hoʻoheheʻe ʻia, ua hana ʻia nā loiloi X-ray diffraction (XRD) a me SEM o nā pauka. Ua hōʻoia nā spectra XRD (Kiʻi 8a) a me nā micrograph SEM (Kiʻi 8b, c) i ke alo o nā kristal vaterite, no ka mea, he ʻano letuse ko lākou a ua ʻike ʻia kahi pilina ma waena o nā piko vaterite a me nā piko precipitate.
(a) Hoʻohālikelike ʻana o nā spectra diffraction X-ray o CaCO3 i hoʻokumu ʻia a me ka vaterite. Nā micrograph SEM o ka vaterite ma (b) 1 kHz a me (c) 5.27 kHz hoʻonui, kēlā me kēia.
Ua hōʻike ʻia nā hopena o nā hoʻāʻo ʻana o ka tunnel makani ma ke Kiʻi 9a, b. Hiki ke ʻike ʻia mai ke Kiʻi 9a ʻo ka wikiwiki o ka erosion paepae (TDV) o ke one i mālama ʻole ʻia ma kahi o 4.32 m/s. Ma ka wikiwiki noi o 1 l/m² (Kiʻi 9a), ʻo nā piʻo o nā laina helu nalowale lepo no nā ʻāpana FA, FS, AA a me UMC ua like like me ka one i mālama ʻole ʻia. Hōʻike kēia ʻaʻole kūpono ka mālama ʻana ma kēia wikiwiki noi a i ka wā e ʻoi aku ai ka wikiwiki o ka makani ma mua o ka TDV, nalowale ka ʻili lepo lahilahi a ua like ka wikiwiki o ka erosion one me ka one i mālama ʻole ʻia. ʻOi aku ka haʻahaʻa o ka piʻo erosion o ka ʻāpana AS ma mua o nā ʻāpana ʻē aʻe me nā abscissas haʻahaʻa (ʻo ia hoʻi ʻo TDV) (Kiʻi 9a). Hōʻike nā pua ma ke Kiʻi 9b ma ka wikiwiki makani kiʻekiʻe loa o 25 m/s, ʻaʻohe erosion i loaʻa i nā one i mālama ʻia ma nā wikiwiki noi o 2 a me 3 l/m². ʻO ia hoʻi, no FS, FA, AS a me UMC, ʻoi aku ka paʻa o nā one i ka ʻinoʻino o ka makani i hoʻokumu ʻia e ka waiho ʻana o CaCO³ ma nā helu noi o 2 a me 3 l/m² ma mua o ka wikiwiki o ka makani kiʻekiʻe loa (ʻo ia hoʻi 25 m/s). No laila, ʻo ka waiwai TDV o 25 m/s i loaʻa i kēia mau hoʻāʻo ʻo ia ka palena haʻahaʻa no nā helu noi i hōʻike ʻia ma ke Kiʻi 9b, koe wale nō ka hihia o AA, kahi i aneane like ai ka TDV me ka wikiwiki o ka tunnel makani kiʻekiʻe loa.
Hoʻāʻo ʻana i ka ʻinoʻino o ka makani (a) Ka emi ʻana o ke kaumaha e kūʻē i ka wikiwiki o ka makani (ka nui o ka noi ʻana he 1 l/m2), (b) Ka wikiwiki o ka haehae ʻana e kūʻē i ka nui o ka noi ʻana a me ke ʻano o ka hoʻohui ʻana (CA no ka calcium acetate, CF no ka calcium formate).
Hōʻike ka Kiʻi 10 i ka ʻino ʻana o ka ʻili o nā puʻu one i mālama ʻia me nā ʻano like ʻole a me nā helu noi ma hope o ka hoʻāʻo ʻana i ka hoʻopōʻino one a ua hōʻike ʻia nā hopena quantitative ma ke Kiʻi 11. ʻAʻole hōʻike ʻia ka hihia i mālama ʻole ʻia no ka mea ʻaʻole ia i hōʻike i ke kūʻē a ua ʻino loa ʻia (ka nalowale nui holoʻokoʻa) i ka wā o ka hoʻāʻo ʻana i ka hoʻopōʻino one. Ua maopopo mai ke Kiʻi 11 ua nalowale ka laʻana i mālama ʻia me ka biocomposition AA i 83.5% o kona kaumaha ma ka helu noi o 2 l/m2 ʻoiai ua hōʻike nā laʻana ʻē aʻe a pau i ka emi ma mua o 30% o ka ʻino i ka wā o ke kaʻina hana hoʻopōʻino one. I ka wā i hoʻonui ʻia ai ka helu noi i 3 l/m2, ua nalowale nā ​​laʻana i mālama ʻia a pau ma lalo o 25% o ko lākou kaumaha. Ma nā helu noi ʻelua, ua hōʻike ka hui FS i ke kūʻē maikaʻi loa i ka hoʻopōʻino one. Hiki ke hoʻopili ʻia ke kūʻē ʻana o ka hoʻopōʻino kiʻekiʻe a me ka liʻiliʻi loa i nā laʻana i mālama ʻia me FS a me AA i ko lākou kiʻekiʻe a me ka liʻiliʻi loa o CaCO3 precipitation (Kiʻi 6f).
Nā hopena o ka hoʻouka kaua ʻana o nā puʻu one o nā ʻano like ʻole ma nā kahe o 2 a me 3 l/m2 (hōʻike nā pua i ke kuhikuhi o ka makani, hōʻike nā keʻa i ke kuhikuhi o ka makani i kū pololei i ka mokulele o ke kaha kiʻi).
E like me ka mea i hōʻike ʻia ma ke Kiʻi 12, ua piʻi aʻe ka nui o ka calcium carbonate o nā ʻano hana āpau i ka piʻi ʻana o ka nui o ka noi mai 1 L/m² a i 3 L/m². Eia kekahi, ma nā helu noi āpau, ʻo ke ʻano hana me ka nui o ka calcium carbonate ʻo FS, a ukali ʻia e FA a me UMC. Hōʻike kēia he ʻoi aku ka kiʻekiʻe o ke kūpaʻa o ka ʻili o kēia mau ʻano hana.
Hōʻike ka Kiʻi 13a i ka loli o ke kū'ē'ē o ka ʻili o nā laʻana lepo i mālama ʻole ʻia, kaohi ʻia a me ka mālama ʻia i ana ʻia e ka hoʻāʻo permeameter. Mai kēia kiʻi, ua maopopo ua piʻi nui ke kū'ē'ē o ka ʻili o nā ʻano UMC, AS, FA a me FS me ka piʻi ʻana o ka nui o ka noi. Eia nō naʻe, ua liʻiliʻi ka piʻi ʻana o ka ikaika o ka ʻili i ka hoʻolālā AA. E like me ka mea i hōʻike ʻia ma ke kiʻi, ʻoi aku ka maikaʻi o ka permeability o ka ʻili o nā ʻano FA a me FS o ka MICP i hoʻohaʻahaʻa ʻole ʻia e ka urea i hoʻohālikelike ʻia me ka MICP i hoʻohaʻahaʻa ʻia e ka urea. Hōʻike ka Kiʻi 13b i ka loli o ka TDV me ke kū'ē'ē o ka ʻili o ka lepo. Mai kēia kiʻi, ua maopopo loa no nā one me ke kū'ē'ē o ka ʻili ma mua o 100 kPa, e ʻoi aku ka wikiwiki o ka wehe ʻana i ka paepae ma mua o 25 m/s. ʻOiai hiki ke ana maʻalahi ʻia ke kū'ē'ē o ka ʻili ma kahi e ka permeameter, hiki i kēia ʻike ke kōkua i ka helu ʻana i ka TDV i ka loaʻa ʻole o ka hoʻāʻo ʻana o ka tunnel makani, no laila e lawelawe ana ma ke ʻano he hōʻailona kaohi maikaʻi no nā noi kahua.
Ua hōʻike ʻia nā hopena SEM ma ke Kiʻi 14. Hōʻike nā Kiʻi 14a-b i nā ʻāpana i hoʻonui ʻia o ka hāpana lepo i mālama ʻole ʻia, kahi e hōʻike maopopo ana he paʻa ia a ʻaʻohe pilina kūlohelohe a i ʻole ka cementation. Hōʻike ʻo Kiʻi 14c i ka micrograph SEM o ka hāpana hoʻomalu i mālama ʻia me ka urea-degraded MICP. Hōʻike kēia kiʻi i ke alo o nā CaCO3 precipitates ma ke ʻano he calcite polymorphs. E like me ka mea i hōʻike ʻia ma nā Kiʻi 14d-o, hoʻopaʻa ka CaCO3 precipitated i nā ʻāpana; hiki ke ʻike ʻia nā kristal vaterite spherical i loko o nā micrograph SEM. Hōʻike nā hopena o kēia haʻawina a me nā haʻawina ma mua e hiki i nā pilina CaCO3 i hana ʻia ma ke ʻano he vaterite polymorphs ke hāʻawi i ka ikaika mechanical kūpono; hōʻike kā mākou mau hopena e piʻi ana ke kū'ē o ka ʻili i 350 kPa a piʻi ka wikiwiki o ka hoʻokaʻawale paepae mai 4.32 a ʻoi aku ma mua o 25 m/s. Ua kūlike kēia hopena me nā hopena o nā haʻawina mua i ʻike ʻia ʻo ka matrix o MICP-precipitated CaCO3 he vaterite, nona ka ikaika mechanical kūpono a me ke kūpaʻa i ka makani13,40 a hiki ke mālama i ke kūpaʻa kūpono i ka makani ma hope o 180 mau lā o ka hōʻike ʻana i nā kūlana kaiapuni kahua13.
(a, b) Nā kiʻi liʻiliʻi SEM o ka lepo i mālama ʻole ʻia, (c) kaohi ʻana i ka hoʻohaʻahaʻa ʻana o ka urea MICP, (df) nā laʻana i mālama ʻia me AA, (gi) nā laʻana i mālama ʻia me AS, (jl) nā laʻana i mālama ʻia me FA, a me (mo) nā laʻana i mālama ʻia me FS ma ka nui o ka noi ʻana o 3 L/m2 ma nā hoʻonui like ʻole.
Hōʻike ka Kiʻi 14d-f ma hope o ka mālama ʻana me nā hui AA, ua hoʻoheheʻe ʻia ka calcium carbonate ma luna o ka ʻili a ma waena o nā ʻāpana one, ʻoiai ua ʻike ʻia kekahi mau ʻāpana one i uhi ʻole ʻia. No nā ʻāpana AS, ʻoiai ʻaʻole i piʻi nui ka nui o CaCO3 i hoʻokumu ʻia (Kiʻi 6f), ua piʻi nui ka nui o nā pilina ma waena o nā ʻāpana one i hoʻokumu ʻia e CaCO3 i hoʻohālikelike ʻia me nā hui AA (Kiʻi 14g-i).
Mai nā Kiʻi 14j-l a me 14m-o ua maopopo he alakaʻi ka hoʻohana ʻana i ka calcium formate ma ke ʻano he kumu calcium i ka hoʻonui hou ʻana i ka ua CaCO3 i hoʻohālikelike ʻia me ka hui AS, kahi e kūlike me nā ana mika calcium ma ke Kiʻi 6f. ʻIke ʻia ua waiho nui ʻia kēia CaCO3 hou ma luna o nā ʻāpana one a ʻaʻole pono e hoʻomaikaʻi i ka maikaʻi o ka hoʻopili ʻana. Hōʻoia kēia i ke ʻano i ʻike mua ʻia: ʻoiai nā ʻokoʻa o ka nui o ka ua CaCO3 (Kiʻi 6f), ʻaʻole ʻokoʻa nui nā ʻano hana ʻekolu (AS, FA a me FS) ma ke ʻano o ka hana anti-eolian (makani) (Kiʻi 11) a me ke kū'ē ʻana o ka ʻili (Kiʻi 13a).
I mea e ʻike maikaʻi ai i nā pūnaewele bacteria i uhi ʻia me CaCO3 a me ka paʻi bacteria ma nā kristal i hoʻoulu ʻia, ua lawe ʻia nā micrographs SEM hoʻonui kiʻekiʻe a ua hōʻike ʻia nā hopena ma ke Kiʻi 15. E like me ka mea i hōʻike ʻia, hoʻoulu ka calcium carbonate ma nā pūnaewele bacteria a hāʻawi i nā nuclei e pono ai no ka ua ma laila. Hōʻike pū ke kiʻi i nā loulou hana a me nā loulou hana ʻole i hoʻoulu ʻia e CaCO3. Hiki ke hoʻoholo ʻia ʻaʻole pono ka hoʻonui ʻana i nā loulou hana ʻole e alakaʻi i ka hoʻomaikaʻi hou ʻana i ke ʻano mechanical. No laila, ʻo ka hoʻonui ʻana i ka ua CaCO3 ʻaʻole ia e alakaʻi i ka ikaika mechanical kiʻekiʻe a he kuleana koʻikoʻi ke ʻano o ka ua. Ua aʻo ʻia kēia kiko ma nā hana a Terzis lāua ʻo Laloui72 a me Soghi lāua ʻo Al-Kabani45,73. No ka ʻimi hou aku i ka pilina ma waena o ke ʻano o ka ua a me ka ikaika mechanical, ua ʻōlelo ʻia nā haʻawina MICP e hoʻohana ana i ke kiʻi µCT, ʻo ia hoʻi ma waho o ka laulā o kēia haʻawina (ʻo ia hoʻi, ka hoʻolauna ʻana i nā hui like ʻole o ke kumu calcium a me ka bacteria no ka MICP ʻaʻohe ammonia).
Ua hoʻoulu ʻo CaCO3 i nā pilina hana a me nā pilina hana ʻole i loko o nā laʻana i mālama ʻia me (a) ka haku mele AS a me (b) ka haku mele FS a waiho i kahi kaha o nā pūnaewele bacteria ma ka sediment.
E like me ka mea i hōʻike ʻia ma nā Kiʻi 14j-o a me 15b, aia kahi kiʻiʻoniʻoni CaCO (e like me ka loiloi EDX, ʻo ka pakeneka o kēlā me kēia mea i loko o ke kiʻiʻoniʻoni he kalapona 11%, oxygen 46.62% a me ka calcium 42.39%, kokoke loa i ka pakeneka o CaCO ma ke Kiʻi 16). Uhi kēia kiʻiʻoniʻoni i nā kristal vaterite a me nā ʻāpana lepo, e kōkua ana i ka mālama ʻana i ka pono o ka ʻōnaehana lepo-sediment. Ua ʻike ʻia ke alo o kēia kiʻiʻoniʻoni ma nā laʻana i mālama ʻia me ka formulate-based formulate.
Hoʻohālikelike ka Papa 2 i ka ikaika o ka ʻili, ka wikiwiki o ka wehe ʻana o ka paepae, a me ka ʻike CaCO3 bioinduced o nā lepo i mālama ʻia me nā ala MICP urea-degrading a me nā ala MICP non-urea-degrading i nā haʻawina mua a me kēia haʻawina. Ua kaupalena ʻia nā haʻawina e pili ana i ke kūpaʻa ʻana o ka makani o nā laʻana dune i mālama ʻia e MICP. Ua noiʻi ʻo Meng et al. i ke kūpaʻa ʻana o ka makani o nā laʻana dune urea-degrading i mālama ʻia e MICP me ka hoʻohana ʻana i kahi mea puhi lau,13 ʻoiai ma kēia haʻawina, ua hoʻāʻo ʻia nā laʻana dune non-urea-degrading (a me nā kaohi urea-degrading) i loko o kahi tunnel makani a mālama ʻia me ʻehā mau hui like ʻole o ka bacteria a me nā mea.
E like me ka mea i ʻike ʻia, ua noʻonoʻo kekahi mau haʻawina mua i nā helu noi kiʻekiʻe e ʻoi aku ana ma mua o 4 L/m213,41,74. He mea kūpono ke hoʻomaopopo ʻana ʻaʻole hiki ke hoʻopili maʻalahi ʻia nā helu noi kiʻekiʻe ma ke kahua mai kahi manaʻo waiwai ma muli o nā kumukūʻai e pili ana i ka lako wai, ka halihali a me ka hoʻopili ʻana i nā nui wai. ʻO nā helu noi haʻahaʻa e like me 1.62-2 L/m2 ua loaʻa pū kekahi i nā ikaika ʻili maikaʻi a hiki i ka 190 kPa a me TDV e ʻoi aku ana ma mua o 25 m/s. Ma ke aʻo ʻana o kēia manawa, ua loaʻa i nā one i mālama ʻia me ka formate-based MICP me ka ʻole o ka hoʻohaʻahaʻa ʻana o ka urea nā ikaika ʻili kiʻekiʻe e like me nā mea i loaʻa me ke ala hoʻohaʻahaʻa urea ma ka pae like o nā helu noi (ʻo ia hoʻi, ua hiki i nā laʻana i mālama ʻia me ka formate-based MICP me ka ʻole o ka hoʻohaʻahaʻa ʻana o ka urea ke hoʻokō i ka pae like o nā waiwai ikaika ʻili e like me ka hōʻike ʻana a Meng et al., 13, Kiʻi 13a) ma nā helu noi kiʻekiʻe. Hiki nō hoʻi ke ʻike ʻia ma ka nui o ka noi ʻana o 2 L/m2, ʻo ka nui o ka calcium carbonate no ka hoʻēmi ʻana i ka ʻino o ka makani ma ka wikiwiki o ka makani o 25 m/s he 2.25% no ka MICP i hoʻokumu ʻia i ka formate me ka ʻole o ka hōʻino ʻia ʻana o ka urea, kahi kokoke loa i ka nui o CaCO3 i koi ʻia (ʻo ia hoʻi 2.41%) i hoʻohālikelike ʻia me nā one i mālama ʻia me ka MICP kaohi me ka hōʻino ʻia ʻana o ka urea ma ka nui o ka noi like a me ka wikiwiki o ka makani like (25 m/s).
No laila, hiki ke hoʻoholo ʻia mai kēia papa ʻaina e hiki i ke ala hōʻino urea a me ke ala hōʻino urea-free ke hāʻawi i ka hana kūpono loa ma ke ʻano o ke kūʻē ʻana o ka ʻili a me TDV. ʻO ka ʻokoʻa nui, ʻaʻole i loaʻa i ke ala hōʻino urea-free ka ammonia a no laila he hopena haʻahaʻa kona i ke kaiapuni. Eia kekahi, ʻo ke ʻano MICP formate me ka ʻole o ka hōʻino urea i hāpai ʻia ma kēia haʻawina e ʻike ʻia ana e hana maikaʻi ma mua o ke ʻano MICP acetate me ka ʻole o ka hōʻino urea. ʻOiai ua aʻo ʻo Mohebbi et al. i ke ʻano MICP acetate me ka ʻole o ka hōʻino urea, ua hoʻokomo kā lākou haʻawina i nā laʻana ma nā ʻili pālahalaha9. Ma muli o ke kiʻekiʻe o ka erosion i hoʻokumu ʻia e ka hoʻokumu ʻana o ka eddy a puni nā laʻana dune a me ka shear hopena, kahi e hopena ai i ka TDV haʻahaʻa, manaʻo ʻia e ʻoi aku ka maopopo o ka erosion makani o nā laʻana dune ma mua o nā ʻili pālahalaha ma ka wikiwiki like.