Anaerobic narkewa

Anaerobic digestion jerin matakai ne wanda microorganisms ke rushe kayan biodegradable batare da iskar oxygen ba. Ana amfani da wannan tsari don dalilai na masana'antu ko na cikin gida don sarrafa sharar gida ko samar da man fetur. Yawancin fermentation da akayi amfani dasu a masana'antu don samar da kayan abinci da abin sha, da kuma fermentation na gida, yana amfani da narkewar anaerobic.

Anaerobic digestion yana faruwa ne ta halitta a wasu ƙasa da kuma a cikin tafkin da kuma tafkin teku, inda yawanci ake kiransa "aikin anaerobic".   Wannan shine tushen iskar gas kamar yadda Alessandro Volta ya gano a cikin 1776 . 

* **Rashin ruwa**

Tsarin narkewa yana farawa tare da hydrolysis na ƙwayoyin cuta na kayan shigarwa. Polymers masu narkewa, kamar carbohydrates, an rushe su zuwa abubuwan da za'a iya narkewa waɗanda ke samuwa ga wasu ƙwayoyin cuta. Kwayoyin cuta na acidogenic sa'an nan kuma suna canza sukari da Amino acid zuwa carbon dioxide, Hydrogen, ammoniya, da kwayoyin acid. A cikin acetogenesis, ƙwayoyin cuta suna canza waɗannan ƙwayoyin ƙwayoyin halitta zuwa acetic acid, tare da ƙarin ammoniya, hydrogen, da carbon dioxide a tsakanin sauran mahadi. A ƙarshe, methanogens suna canza waɗannan samfuran zuwa methane da carbon dioxide. Yawan mutanen archaea na methanogenic suna taka muhimmiyar rawa a cikin maganin ruwa mai guba.

Ana amfani da narkewar anaerobic a matsayin wani ɓangare na tsari don magance sharar gida da datti. A matsayin wani ɓangare na tsarin sarrafa sharar gida, narkewar anaerobic yana rage fitar da iskar gas a cikin yanayi. Ana Kuma iya ciyar da masu tonowa na anaerobic tare da amfanin gona mai amfani, kamar masara.

Ana amfani da narkewar anaerobic a matsayin tushen makamashi mai sabuntawa. Wannan tsari yana samar da iskar gas, wanda ya kunshi methane, carbon dioxide, da kuma alamun wasu iskar gas 'mai gurbatawa'. Ana iya amfani da wannan iskar gas kai tsaye a matsayin man fetur, a cikin haɗin zafi da injin iskar gas  ko kuma inganta shi zuwa biomethane mai ingancin iskar gas. Hakanan ana iya amfani da sinadarin da aka samar a matsayin taki.

With the re-use of waste as a resource and new technological approaches that have lowered capital costs, anaerobic digestion has in recent years received increased attention among governments in a number of countries, among these the United Kingdom (2011), Germany, Denmark (2011), and the United States.
 

## Tsarin
 
Yawancin microorganisms suna shafar narkewar anaerobic, gami da ƙwayoyin cuta masu samar da acid (acetogens) da archaea masu samar da methane (methanogens). Wadannan kwayoyin suna inganta tsarin sunadarai dayawa wajen canza biomass zuwa biogas.

An cire iskar oxygen daga halayen ta hanyar hanawa ta jiki. Anaerobes suna amfani da masu karɓar lantarki daga wasu tushe banda iskar oxygen. Wadannan masu karɓa na iya zama kayan kwayoyin halitta da kansu ko kuma ana iya samar dasu ta hanyar inorganic oxides daga cikin kayan shigarwa. Lokacin da tushen iskar oxygen a cikin tsarin anaerobic yasamo asali ne daga kayan kwayoyin halitta da kansa, samfuran ƙarshen 'tsakanin' sune barasa, Aldehydes, da kwayoyin acid, tare da carbon dioxide. A gaban ƙwararrun methanogens, ana canza matsakaici zuwa 'ƙarshe' samfuran methane, carbon dioxide, da matakan trace na hydrogen sulfide. A cikin tsarin anaerobic, yawancin makamashi na sinadarai dake cikin kayan farawa ana fitar dasu ta hanyar methanogenic archaea a matsayin methane.

Yawan microorganisms anaerobic yawanci suna ɗaukar lokaci mai mahimmanci don kafa kansu don zama cikakke. Sabili da haka, al'ada ce ta gabatar da microorganisms na anaerobic daga kayan dake da yawan jama'a, tsari da aka sani da "shuka" digesters, yawanci ana cika shi tare da ƙara datti ko laka na shanu.

### Matakan tsari
Matakai huɗu masu mahimmanci na narkewar anaerobic sun haɗa da hydrolysis, acidogenesis, Acetogenesis da methanogenesis.Za'a iya bayyana tsarin gabaɗaya ta hanyar halayen sunadarai, inda kayan kwayoyin halitta kamar glucose ke narkewa cikin carbon dioxide (CO2) da methane (CH4) ta hanyar microorganisms na anaerobic.
C66 → 3CO2 + 3CH4


A mafi yawan lokuta, biomass ya ƙunshi manyan polymers na kwayoyin halitta. Don ƙwayoyin cuta a cikin anaerobic digesters don samun damar ƙarfin makamashi na kayan, waɗannan sarƙoƙi dole ne a fara karya su cikin ƙananan sassan su. Wadannan sassan, ko monomers, kamar sukari, suna samuwa ga wasu ƙwayoyin cuta. Tsarin karya waɗannan sarƙoƙi da narkar da ƙananan kwayoyin zuwa mafita ana kiransa hydrolysis. Sabili da haka, hydrolysis na waɗannan abubuwan polymeric masu nauyi shine matakin farko days dace a cikin narkewar anaerobic. Ta hanyar hydrolysis ana rarraba kwayoyin halitta masu rikitarwa zuwa sukari mai sauƙi, amino acid, da fatty acids.

Acetate da hydrogen da aka samar a matakai na farko ana iya amfani dasu kai tsaye ta hanyar methanogens. Sauran kwayoyin, irin su volatile fatty acids (VFAs) tare da sarkar da tafi na acetate dole ne a fara catabolised cikin mahaɗan da methanogens zasu iya amfani dasu kai tsaye.

* **Acidogenesis**

Tsarin halittu na acidogenesis yana haifar da cigaba da rushewar sauran abubuwan da suka rage ta hanyar ƙwayoyin cuta na acidogenic (mai yisti). A nan, ana halicci VFAs, tare da ammoniya, carbon dioxide, da hydrogen sulfide, da sauran kayayyaki. Tsarin acidogenesis yayi kama da yadda madara keda zafi.

* **Acetogenesis**

Mataki na uku na narkewar anaerobic shine Acetogenesis . A nan, kwayoyin da aka kirkira ta hanyar acidogenesis suna kara narkewa ta hanyar acetogens don samar da yawancin acetic acid, da carbon dioxide da hydrogen.

* **Methanogenesis**

Mataki na ƙarshe na narkewar anaerobic shine tsarin halittu na methanogenesis. A nan, methanogens suna amfani da samfuran tsakiya na matakan da suka gabata kuma suna canza su zuwa methane, carbon dioxide, da ruwa. Wadannan abubuwan sun hada da mafi yawan iskar gas da aka fitar daga tsarin. Methanogenesis yanada hankali ga pH mai girma da ƙananan kuma yana faruwa tsakanin pH 6.5 da pH 8.  Sauran, kayan da baza'a iya narkewa ba, ƙwayoyin cuta bazasu iya amfani dasu ba kuma duk wani ragowar ƙwayoyin ƙwayoyin halitta ya zama narkewa.

### Tsarinsa

Anaerobic digesters za'a iya tsarawa da injiniya don aiki ta amfani da wasu saiti daban-daban kuma ana iya rarraba su cikin tsari vs. yanayin cigaba, yanayin zafin jiki na mesophilic vs. yanayin zafin rana, babban vs. ƙananan sashi na abubuwa masu ƙarfi, da kuma mataki ɗaya vs. matakai dayawa. Cigaba da tsari yana buƙatar ƙirar da tafi rikitarwa, amma har yanzu, yana iya zama mafi arha fiye da tsarin rukuni, saboda tsarin rukuni yana buƙatar ƙarin kuɗin gini na farko da kuma ƙarar ƙwayoyin ƙwayoyin cuta (wanda aka shimfiɗa a cikin rukuni dayawa) don sarrafa adadin sharar gida kamar yadda tsarin cigaba ke narkewa. Ana buƙatar ƙarfin zafi mafi girma a cikin tsarin thermophilic idan aka kwatanta da tsarin mesophilic, amma tsarin thermophylic yana buƙatar ɗan lokaci kaɗan kuma yana da ƙarfin fitar da gas mafi girma da ƙarancin iskar gas, don haka dole ne mutum yayi la'akari da wannan cinikayya a hankali. Don abun ciki mai ƙarfi, ƙasa zai kula da har zuwa 15% abun ciki mai mahimmanci. Sama da wannan matakin ana ɗaukar abun ciki mai ƙarfi kuma ana iya saninsa da narkewar bushe. A cikin tsari guda ɗaya, ɗayan reactor yana da matakai huɗu na narkewar anaerobic. Tsarin matakai dayawa yana amfani da masu amsawa biyu ko fiye don narkewa don raba matakan methanogenesis da hydrolysis.

#### Batch ko cigaba
Ana iyayin narkewar anaerobic a matsayin tsari na rukuni ko tsari na cigaba. A cikin tsarin rukuni, ana ƙara biomass a cikin reactor a farkon tsari. Ana rufe reactor ɗin na tsawon lokacin aikin. A cikin mafi sauki tsari tsari yana buƙatar inoculation tare da riga an sarrafa kayan don fara narkewar anaerobic. A cikin yanayin daya dace, za'a samar da iskar gas tare da tsarin rarraba na al'ada a tsawon lokaci. Masu aiki na iya amfani da wannan gaskiyar don tantance lokacin da sukayi imanin cewa tsarin narkewar kwayoyin halitta ya kammala. Za'a iya samun matsaloli masu tsanani na wari idan an buɗe ma'aunin ma'auni kuma an kwashe shi kafin a kammala aikin sosai. Wani nau'in tsari mai cigaba ya iyakance matsalolin wari ta hanyar haɗa narkewar anaerobic tare da composting a cikin akwati. A cikin wannan hanyar inoculation yana faruwa ta hanyar amfani da percolate mai sake zagayawa. Bayan an kammala narkewar anaerobic, ana adana biomass a cikin reactor wanda ake amfani dashi don yin amfani dashi a cikin akwati kafin a buɗe shi  Kamar yadda narkewar batch yanada sauƙi kuma yana buƙatar ƙananan kayan aiki da ƙananan matakan aikin ƙira, yawanci nau'in narkewa ne mai rahusa.  Yin amfani da ma'aunin ma'auni fiye da ɗaya a cikin shuka na iya tabbatar da samar da iskar gas.

A cikin cigaba da narkewa, ana ƙara kwayoyin halitta koyaushe (cigaba da cikakke) ko ƙarawa a matakai zuwa reactor (cigaba mai gudana; na farko a cikin - na farko fita). A nan, ana cire samfuran ƙarshe koyaushe ko lokaci-lokaci, wanda ke haifar da samar da iskar gas. Ana iya amfani da digesters guda ɗaya ko dayawa a cikin jerin. Misalan wannan nau'in narkewar anaerobic sun haɗa da masu bada wutar lantarki masu cigaba, bargo na laka na anaerobic, shimfida gadaje masu laushi, da masu ba'a na ciki.

#### Yanayin zafi
Matakan zafin jiki na yau da kullun guda biyu don anaerobic digesters suna ƙayyade nau'in methanogens a cikin digesters: 

* Mesophilic narkewa yana faruwa mafi kyau a kusa da 30 zuwa 38 ° C, ko a yanayin zafi tsakanin 20 zuwa 45 ° C, inda mesophiles sune manyan microorganisms.&nbsp;&nbsp;
* Thermophilic digestion yana faruwa mafi kyau a kusa da 49 zuwa 57 °C, ko a yanayin zafi har zuwa 70 °C, inda thermophiles sune manyan microorganisms.&nbsp;&nbsp;

An kai ga iyaka a Bolivia, tare da narkewar anaerobic a yanayin aiki na zafin jiki na kasa da 10 ° C. &nbsp;Tsarin anaerobic yana da jinkiri sosai, yana ɗaukar fiye da sau uku na tsarin lokaci na mesophilic na yau da kullun. A cikin aikin gwaji a Jami'ar Alaska Fairbanks, mai narkewa mai lita 1,000 ta amfani da psychrophiles da aka girbe daga "mud daga tafkin daskarewa a Alaska" ya samar da lita 200-300 na methane a kowace rana, kimanin 20 zuwa 30% na fitarwa daga digesters a yanayin zafi. &nbsp;Mesophilic jinsuna sunfi yawan thermophiles, kuma sunfi jurewa ga canje-canje a yanayin muhalli fiye da thermophiels. Saboda haka, ana ɗaukar tsarin Mesophilic yafi kwanciyar hankali fiye da tsarin narkewar thermophilic. Sabanin haka, yayin da tsarin narkewar thermophilic ake la'akari da rashin kwanciyar hankali, shigarwar makamashi tafi girma, tare da cire karin iskar gas daga kwayoyin halitta a daidai lokacin. Karin yanayin zafi yana sauƙaƙa saurin amsawa, don haka saurin iskar gas. Aiki a yanayin zafi mafi girma yana sauƙaƙa raguwar pathogen na digestate. A cikin ƙasashe inda dokoki, kamar Dokokin Dabbobi a cikin Tarayyar Turai, suna buƙatar narkewa don saduwa da wasu matakan rage kwayar cuta akwai yiwuwar amfanin amfani da yanayin zafi maimakon mesophilic.

Ana iya amfani da ƙarin magani don rage lokacin riƙewa don samar da iskar gas. Misali, wasu matakai sun ragargaza substrates don kara girman ko amfani da matakin pre-magani na zafi (kamar pasteurisation) don inganta fitar da iskar gas. Hakanan za'a iya amfani da tsarin pasteurisation don rage yawan pathogenic a cikin digestate, yana barin anaerobic digester. Ana iya samun pasteurisation ta hanyar maganin zafi tare da Maceration na abubuwa masu ƙarfi.

#### Abubuwan dake ciki
A cikin al'ada, sigogi daban-daban na aiki suna da alaƙa da abubuwan dake cikin kayan abinci ga masu bincike:

* Abubuwan dake da ƙarfi (mai bushewa - mai ɗorewa) 
* Abubuwa masu ƙarfi (ruwa - abinda za'a iya amfani dashi) 
* Ƙananan abubuwa masu ƙarfi (ruwa - mai ƙwanƙwasawa) 

An tsara high solids (dry) digesters don sarrafa kayan tare da abun ciki mai ƙarfi tsakanin 25 da 40%. Ba kamar masu narkewa ba waɗanda ke aiwatar da ƙwayoyin ƙwayoyin cuta, an tsara masu narkewar ƙwayoyin (ƙasassun - ƙwayoyin da za'a iya ɗorawa) don aiwatar da substrates masu ƙarfi batare da ƙara ruwa ba. Hanyoyin farko na busassun digesters sune cigaba da kwarara na tsaye da kuma tarin ramin ramin dake kwance. Cigaba da kwarara kwarara kwaskwarima ne tsaye, cylindrical tankuna inda ake cigaba da ciyarwa a saman digester, kuma yana gudana ƙasa ta hanyar nauyi yayin narkewa. A cikin masu tono ramin ramin, ana ajiye kayan abinci a cikin ɗakunan da ke kama da ramin tare da ƙofar da batada iskar gas. Babu wata hanyar dake da haɗuwa a cikin mai narkewa. Adadin gyaran da akayi, kamar cire gurbataccen abu, ya dogara da yanayin magudanar da ake sarrafawa da kuma ingancin da ake so na narkewa. Rage girman (girkewa) yana da fa'ida a cikin tsarin tsaye na cigaba, yayin da yake hanzarta narkewa, yayin da tsarin rukuni ke guje wa niƙa kuma a maimakon haka yana buƙatar tsari (misali sharar gida) don rage tarwatsawar tarin da aka ɗora. Cigaba da bushewa a tsaye suna da karamin sawun saboda gajeren lokacin riƙewa da ƙirar tsaye. Za'a iya tsara masu narkewa don aiki a cikin ko dai abun ciki mai ƙarfi, tare da jimlar abubuwan da aka dakatar (TSS) mafi girma fiye da ~ 20%, ko kuma ƙananan abubuwan da ke ƙasa da ~ 15%. 

High solids (ruwa) digesters suna aiwatar da wani m slurry wanda ke buƙatar ƙarin makamashi shigarwa don motsawa da aiwatar da feedstock. Kaurin kayan na iya haifar da matsalolin dake tattare da abrasion. High solids digesters yawanci suna da ƙananan buƙatun ƙasa saboda ƙananan ƙididdigar dake da alaƙa da danshi. High solids digesters kuma suna buƙatar gyara na al'ada aiki lissafi (misali gas samar, riƙewa lokaci, kinetics, da dai sauransu) asali bisa ga ra'ayoyin narkewar datti, tunda manyan sassa na feedstock taro suna iya canzawa zuwa biogas.

Low solids (ruwa) digesters na iya jigilar kayan ta hanyar tsarin ta amfani da daidaitattun famfo waɗanda ke buƙatar ƙarancin shigar da makamashi. Low solids digesters suna buƙatar ƙasa mai yawa fiye da high solids saboda karuwar girma dake da alaƙa da karuwar ruwa-da-feedstock rabo na digesters. Akwai fa'idodi dake da alaƙa da aiki a cikin yanayin ruwa, saboda yana bada damar yaduwar kayan aiki da kuma hulɗa tsakanin ƙwayoyin cuta da abincin su. Wannan yana bawa ƙwayoyin cuta damar samun damar abubuwan da suke ci, kuma yana ƙara yawan samar da iskar gas.

#### Rashin jituwa
Ana iya daidaita tsarin narkewa tare da matakai daban-daban na rikitarwa. A cikin **Tsarin narkewa guda ɗaya** (mataki ɗaya), duk halayen halittu suna faruwa a cikin guda ɗaya, mai rufewa ko tanki mai riƙewa. Amfani da mataki ɗaya yana rage farashin gini, amma yana haifar da ƙarancin kula da halayen dake faruwa a cikin tsarin. Kwayoyin cuta na acidogenic, ta hanyar samar da acid, rage pH na tankin. Methanogenic archaea, kamar yadda aka tsara a baya, yana aiki a cikin iyakar pH. Sabili da haka, halayen halittu na nau'o'i daban-daban a cikin na'urar sarrafawa guda ɗaya na iya kasancewa cikin gasa kai tsaye da juna. Wani tsarin amsawa na mataki daya shine lagoon anaerobic. Wadannan lagoons suna kama da tafki, wuraren da akayi amfani dasu don magani da adana turare na dogon lokaci. A nan halayen anaerobic suna ƙunshe a cikin laka na anaerobic na halitta dake cikin tafkin.

A cikin **tsarin narkewa na matakai biyu** (multistage), ana inganta tasoshin narkewa daban-daban don kawo matsakaicin iko akan al'ummomin ƙwayoyin cuta dake zaune a cikin digesters. Kwayoyin cuta na acidogenic suna samar da sinadarin kwayoyin halitta kuma suna girma da sauri da haifuwa fiye da archaea na methanogenic. Methanogenic archaea suna buƙatar pH mai ɗorewa da zafin jiki don inganta aikin su.

A cikin yanayi na yau da kullun, hydrolysis, acetogenesis, da acidogenesis suna faruwa a cikin taskar farko. Ana dumama kayan kwayoyin zuwa zafin jiki da ake buƙata (ko dai mesophilic ko thermophilic) kafin a zuba su cikin methanogenic reactor. Tankunan hydrolysis na farko ko acidogenesis kafin methanogenic reactor na iya samar da mafita ga adadin da aka kara abinci. Wasu ƙasashen Turai suna buƙatar digiri na maganin zafi mai girma don kashe ƙwayoyin cuta masu cutarwa a cikin sharar shigarwa. A wannan misali, akwai yiwuwar pasteurisation ko matakin sterilisation kafin narkewa ko tsakanin tankuna biyu na narkewa. Musamman, ba zai yiwu a ware matakai daban-daban ba, kuma sau dayawa ana samar da wasu iskar gas a cikin tankunan hydrolysis ko acidogenesis.

#### Lokacin zama
Lokacin zama a cikin mai narkewa ya bambanta da adadin da nau'in kayan abinci, da kuma tsarin tsarin narkewa. A cikin nau'ikan narkewar mesophilic na yau da kullun, lokacin zama ya bambanta tsakanin kwanaki 15 zuwa 40,  yayin da ga narkewar thermophilic guda ɗaya, lokutan zama yawanci suna da sauri kuma suna ɗaukar kusan kwanaki 14. &nbsp;&nbsp;Yanayin plug-flow na wasu daga cikin wadannan tsarin zai nufin cewa ba'a  fahimci cikakken lalacewar kayan a cikin wannan lokaci ba. A wannan taron, digestate fita daga tsarin zai zama duhu a launi kuma yawanci zai sami karin wari.

A cikin yanayin narkewar bargo na anaerobic (UASB), lokutan zama na hydraulic na iya zama ɗan gajeren lokaci kamar awa 1 zuwa rana 1, kuma lokutan riƙewa na iya zama har zuwa kwanaki 90. Ta wannan hanyar, tsarin UASB yana iya raba abubuwa masu ƙarfi da lokutan riƙe ruwa tare da amfani da bargo na laka. Masu cigaba da tonowa suna da na'urorin inji ko na ruwa, dangane da matakin abubuwa masu ƙarfi a cikin kayan, don haɗa abubuwan dake ciki, suna bada damar ƙwayoyin cuta da abinci su kasance cikin hulɗa. Har ila yau, suna bada izinin cire kayan da suka wuce gona da iri don kula da ƙarar data dace a cikin tankunan narkewa.

#### Matsi
Wani cigaba na baya-bayan nan a cikin ƙirar anaerobic reactor shine High-pressure anaerobic digestion (HPAD) wanda kuma ake kira Autogenerative High Pressure Digestion (AHPD). Wannan dabarar tana samar da iskar gas tare da babban abun ciki na methane. Carbon dioxide da aka samar a cikin iskar gas ya narke cikin ruwa a ƙarƙashin matsin lamba sannan methane yayi. Saboda haka samar da biogas yafi wadata da methane. Bincike a Jami'ar Groningen ya nuna cewa al'ummar ƙwayoyin cuta suna canzawa a cikin abun dake ciki a ƙarƙashin tasirin matsin lamba. Kowane nau'in ƙwayoyin cuta suna da yanayin da yafi dacewa inda suke girma da kuma ninkawa da sauri. An san su da pH, zafin jiki, salinity da dai sauransu amma matsin lamba yana daya daga cikinsu. Wasu nau'o'in sun saba da rayuwa a cikin teku mai zurfi inda matsin lamba yafi girma fiye da matakin teku. Wannan yasa ya yiwu a cikin irin wannan jijiya kamar sauran sigogi na tsari kamar zafin jiki, Lokacin riƙewa, pH don rinjayar tsarin narkewar anaerobic.

### Hanawa
 
Ana iya hana tsarin narkewar anaerobic ta hanyar mahadi dayawa, yana shafar ɗaya ko fiye daga cikin ƙungiyoyin ƙwayoyin cuta dake da alhakin matakai daban-daban na lalacewar kwayoyin halitta. Matsayin hanawa ya dogara, a tsakanin sauran dalilai, akan maida hankali ga mai hanawa a cikin digester. Masu hanawa masu yuwuwa sune ammoniya,  sulfide, ions na ƙarfe mai haske (Na, K, Mg, Ca, Al), ƙarfe mai nauyi, wasu kwayoyin halitta (chlorophenols, halogenated aliphatics, N-substituted aromatics, long chain fatty acids), da dai sauransu.[2]

An nuna jimlar ammoniya nitrogen (TAN) don hana samar da methane. Bugu da ƙari, yana lalata al'ummar microbial, yana tasiri ga kira na acetic acid. Acetic acid yana daya daga cikin karfi a cikin samar da methane. A fiye da 5000 MG / L TAN, ana buƙatar daidaita pH don kiyaye amsawar. &nbsp;TAN mai da hankali sama da 1700- 1800 MG / L yana hana samar da methane kuma amfanin gona yana raguwa a mafi yawan TAN. &nbsp;Babban TAN mai yawa yana haifar da martani don juya acidic kuma yana haifar da tasirin domino na hanawa. Jimlar ammoniya nitrogen shine haɗuwa da ammoniya kyauta da ammoniyya mai ionized. Ana samar da TAN ta hanyar rage kayan dake cikin nitrogen, yawanci sunadarai kuma zai gina a cikin narkewar anaerobic. Wannan ya dogara da kayan abinci na kwayoyin da aka ciyar da tsarin. A cikin ayyukan tsabtace ruwa, ana rage TAN ta hanyar nitrification. Nitrification tsari ne na aerobic inda kwayoyin cuta na heterotrophic ke cinye TAN. Wadannan kwayoyin cuta suna fitar da nitrate da nitrite wanda daga baya aka canza su zuwa iskar nitrogen ta hanyar tsarin denitrification. Hydrolysis da acidogenesis na iya shafar TAN. A cikin yanayin mesophilic, an gano hanawa don hydrolysis a 5500 MG / L TAN, yayin da hana acidogenesis ke faruwa a 6500 MG / L L TAN.&nbsp;&nbsp;

## Abinci

Mafi mahimmancin batun farko yayin la'akari da aikace-aikacen tsarin narkewar anaerobic shine kayan abinci ga tsari. Kusan kowane abu na kwayoyin halitta za'a iya sarrafa shi tare da narkewar anaerobic;  duk da haka, idan samar da iskar gas shine manufar, matakin putrescibility shine mabuɗin abin da ke cikin nasarar aikace-aikacen.  Mafi lalacewa (mai narkewa) kayan, mafi girman iskar gas tana iya fitowa daga tsarin.

Abinci na iya haɗawa da kayan sharar gida, kamar takardar sharar gidaje, yankan ciyawa, abincin daya rage, datti, da sharar dabbobi. Sharar katako itace bata da kyau, saboda basu da tasiri ta hanyar narkewa, saboda yawancin anaerobes ba su iya lalata lignin ba. Xylophagous anaerobes (masu amfani da lignin) ko maganin zafin jiki mai girma, kamar pyrolysis, ana iya amfani dashi don karya lignin. Ana iya ciyar da masu narkewar anaerobic tare da amfanin gona na musamman, kamar silage, don samar da iskar gas. A cikin Jamus da nahiyar Turai, ana kiran waɗannan wuraren a matsayin tsire-tsire na "biogas". Shuka mai sarrafawa ko shuka mai sarrafa kansa yawanci mai sarrafa kansa ne wanda ke karɓar kayan shigarwa guda biyu ko fiye don narkewa a lokaci guda.

Tsawon lokacin da ake buƙata don narkewar anaerobic ya dogara da rikitarwa na sinadarai na kayan. Abubuwan dake da wadataccen sukari mai sauƙin narkewa suna rushewa da sauri, yayin da kayan lignocellulosic dake da arziki a cikin cellulose da hemicellulose polymers na iya ɗaukar lokaci mai tsawo don rushewa. Anaerobic microorganisms gabaɗaya ba sa iya karya lignin, ɓangaren ƙanshi mai ƙanshi na biomass.

Anaerobic digesters an tsara su ne don aiki ta amfani da datti da tururi. Rashin ruwa da turare ba, duk da haka, kayan da keda damar narkewa na anaerobic bane, kamar yadda kayan biodegradable sun riga sun sami yawancin abubuwan dake cikin makamashi da dabbobi da suka samar dashi suka fitar. Sabili da haka, masu rarrabawa dayawa suna aiki tare da codigestion na nau'ikan abinci guda biyu ko fiye. Misali, a cikin mai narkewa na gona wanda ke amfani da turare na madara a matsayin kayan abinci na farko,  ana iya ƙara samar da iskar gas sosai ta hanyar ƙara kayan abinci na biyu, misali, ciyawa da masara (abin da ake amfani da shi a gona), ko kayan abinci daban-daban, kamar sharar gida, kitse, mai da mai daga gidajen cin abinci, da dai sauransu.

Masu tonowa suna sarrafa amfanin gona na makamashi na iya cimma matsaya mai girma da samar da iskar gas. Tsarin Slurry-kawai yawanci sun fi rahusa, amma suna samar da karancin makamashi fiye da waɗanda ke amfani da amfanin gona, kamar masara da ciyawa; ta hanyar amfani da kayan amfanin gona mai sauƙi (30%), tsire-tsire na narkewa na anaerobic na iya ƙara fitar da makamashi sau goma kawai na farashin babban birnin, dangane da tsarin slurry-kai kawai.

### Abubuwan dake ciki
Wani la'akari na biyu daya shafi kayan abinci shine abun ciki na danshi. Dry, substrates stackable, kamar abinci da sharar gida, sun dace da narkewa a cikin ɗakunan rami. Tsarin salon ramin yawanci yana da kusan fitar da ruwa mai guba, don haka wannan salon tsarin yana da fa'idodi inda fitar da ruwa na digester shine alhakin. Idan kayan yafi ruwan sama, yafi dacewa da sarrafawa tare da ma'auni na ma'aunin famfo maimakon famfo na kankare mai karfi da kuma hanyar motsa jiki. Har ila yau, mafi ruwan da kayan, mafi girma da yanki da yake ɗauka dangane da matakan iskar gas da aka samar. Abubuwan da ke cikin danshi na kayan abinci da akayi niyya zasu kuma shafi irin tsarin da akayi amfani dashi don maganin sa. Don amfani da babban mai ƙarfi anaerobic digester don narkewar abinci, ya kamata ayi amfani da wakilai masu yawa, kamar takin mai, don ƙara abubuwan dake cikin kayan shigarwa. Wani mahimmin la'akari shine rabo na carbon:nitrogen na kayan shigarwa. Wannan rabo shine ma'auni na abinci da kwayar cuta ke buƙata don girma; mafi kyawun rabo na C:N shine 20-30:1. Yawan N na iya haifar da hana narkewar ammoniya.

### Cutar
Matsayin gurɓataccen kayan abinci shine mahimmin la'akari yayin amfani da narkewar rigar ko narkewar plug-flow.

Idan kayan abinci ga masu tantancewa suna da matakai masu mahimmanci na gurɓataccen jiki, kamar filastik, gilashi, ko karafa, to za'a buƙaci sarrafawa don cire gurɓata don amfani da kayan. Idan ba a cire shi ba, to ana iya toshe digesters kuma bazasu  yi aiki yadda ya kamata ba. Wannan batun gurɓataccen baya faruwa tare da narkewar bushe ko tsire-tsire masu tsayi na anaerobic (SSAD), tunda SSAD yana kula da bushewa, biomass mai ɗorewa tare da babban kashi na abubuwa masu ƙarfi (40-60%) a cikin ɗakunan gas-tight da ake kira akwatunan fermenter. Tare da wannan fahimtar ne aka tsara tsire-tsire na maganin halittu. Mafi girman matakin gyaran abinci da ake buƙata, za'a buƙaci ƙarin kayan aiki, kuma, saboda haka, aikin zai sami farashin kuɗi mafi girma. Cibiyar Kula da Amfanin Gida ta Kasa.

Bayan rarraba ko tantancewa don cire duk wani gurbataccen jiki daga kayan abinci, ana sau dayawa yanka kayan, kuma ana yin su da inji ko hydraulically don ƙara girman dake samuwa ga ƙwayoyin cuta a cikin digesters kuma, saboda haka, ƙara saurin narkewa. Za'a iya samun maceration na abubuwa masu ƙarfi ta hanyar amfani da famfo na chopper don canja wurin kayan abinci a cikin iska mai narkewa, inda maganin anaerobic ke faruwa.

### Abubuwan dake tattare dasu
Abinda ke cikin substratum shine babban abu wajen tantance yawan amfanin methane da ƙimar samar da methane daga narkewar biomass. Hanyoyi don ƙayyade halaye na kayan abinci suna samuwa, yayin da sigogi kamar su solids, elemental, da kwayoyin halitta suna da mahimmanci ga ƙirar digester da aiki. Ana iya kimanta amfanin methane daga abubuwan dake cikin substratum tare da kimantawa game da lalacewa (kashi na substratum wanda aka canza zuwa biogas a cikin reactor).  Don yin hasashen abun dake ciki na iskar gas (ƙananan dangi na methane da carbon dioxide) yazama dole a kimanta rarrabawar carbon dioxide tsakanin matakai na rabuwa da gas, wanda ke buƙatar ƙarin bayani (zafin jiki, pH, da abun dake cikin substratum) da kuma samfurin sinadarai. Ana kuma yin ma'auni kai tsaye na yiwuwar biomethanation ta amfani da juyin halitta na gas ko gwaje-gwaje na kwanan nan.

## Aikace-aikacen

Yin amfani da fasahar narkewar anaerobic na iya taimakawa wajen rage fitar da iskar gas a hanyoyi masu mahimmanci:

* Canja wurin man fetur
* Ragewa ko kawar da sawun makamashi na sharar gida
* Rage fitar da methane daga wuraren zubar da shara
* Cire kayan aikin sinadarai da aka samar da masana'antu
* Rage motsi na motoci
* Rage asarar wutar lantarki
* Rage amfani da LP Gas don dafa abinci
* Wani muhimmin bangare na shirye-shiryen Zero Waste.

### Magani da tsabtace ruwa

Anaerobic digestion yadace da kayan kwayoyin halitta, kuma ana amfani dashi akai-akai don masana'antu, Ruwa mai guba da kuma Maganin datti. Anaerobic digestion, tsari mai sauƙi, na iya rage yawan kwayoyin halitta wanda in ba haka baza'a zubar dashi a teku,  zubar dasu a cikin shara, ko ƙone su a cikin incinerators. 

Matsi doka dokokin da suka shafi muhalli akan hanyoyin zubar da sharar gida a cikin Kasashe masu tasowa yakara aikace-aikacen narkewar anaerobic a matsayin tsari don rage yawan sharar gida da samar da kayan aiki masu amfani. Ana iya amfani dashi don aiwatar da ɓangaren da aka raba na sharar gida ko kuma a madadin haka an haɗa shi da tsarin rarraba na inji, don aiwatar da raguwar sharar gida. Wadannan wuraren ana kiransu tsire-tsire na maganin halittu na inji.

Idan aka zubar da sharar da aka sarrafa a cikin anaerobic digesters a cikin wani sharar gida, zai rushe ta halitta kuma sau dayawa anaerobically. A wannan yanayin, iskar za ta tsere cikin yanayi. Kamar yadda methane ya ninka sau 20 a matsayin iskar gas fiye da carbon dioxide, wannan yana da mummunar tasirin muhalli.

A cikin ƙasashen dake tattara sharar gida, amfani da wuraren narkewar anaerobic na gida na iya taimakawa wajen rage yawan sharar dake buƙatar sufuri zuwa wuraren da aka zubar da shara ko wuraren konewa. Wannan rage nauyin sufuri yana rage hayakin carbon daga motocin tattarawa. Idan an saka wuraren narkewar anaerobic a cikin hanyar sadarwar rarraba wutar lantarki, zasu iya taimakawa rage asarar wutar lantarki dake da alaƙa da jigilar wutar lantarki a kan grid na ƙasa.

Ana iya amfani da narkewar anaerobic don maganin gurɓataccen laka da PFAS. Binciken a shekarar 2024 ya nuna cewa narkewar anaerobic, haɗe da adsorption a cikin aikace-aikacen carbon da ƙarfin lantarki na iya cire har zuwa 61% na PFAS daga laka.

### Zamani na wutar lantarki
A cikin kasashe masu tasowa, tsarin narkewar anaerobic na gida dana gona yana bada damar samun makamashi mai tsada don dafa abinci da hasken wuta.Daga shekarar 1975, kasar Sin da Indiya dukansu suna da manyan tsare-tsaren tallafin gwamnati don daidaita ƙananan tsire-tsire na gas don amfani a cikin gida don dafa abinci da hasken wuta. A halin yanzu, ayyukan narkewar anaerobic a kasashe masu tasowa na iya samun tallafin kuɗi ta hanyar Tsarin Tsabtace Ci Gaban Majalisar Dinkin Duniya idan sun iya nuna cewa suna samar da rage hayakin carbon.

Ana iya amfani da methane da wutar lantarki da aka samar a wuraren narkewar anaerobic don maye gurbin makamashi da aka samo daga man fetur, sabili da haka rage hayaki na iskar gas, saboda carbon a cikin kayan biodegradable wani ɓangare ne na sake zagayowar carbon. Carbon da aka saki cikin yanayi daga konewar biogas an cire shi ta shuke-shuke don su girma a cikin 'yan kwanakin nan, yawanci a cikin shekaru goma da suka gabata, amma mafi yawanci a tsakanin lokacin girma na ƙarshe. Idan tsire-tsire sun sake girma, suna fitar da carbon daga sararin samaniya, tsarin zai zama tsaka-tsaki na carbon. Sabanin haka, an tsare carbon a cikin burbushin burbushin halittu a cikin ƙasa na miliyoyin shekaru, wanda konewa ke kara yawan matakan carbon dioxide a cikin yanayi. Samar da wutar lantarki ta hanyar narkewar anaerobic yafi dacewa da manyan ayyuka, maimakon ƙananan gonaki, saboda manyan ayyuka suna da ƙarar turare wanda zai iya sa tsarin yazama mai cin gashin kansa.

Biogas daga Maganin datti a wasu lokuta ana amfani dashi don gudanar da Injin gas don samar da wutar lantarki, wasu ko dukansu ana iya amfani da su don gudanar da ayyukan datti. Ana amfani da wasu zafin sharar gida daga injin don dumama mai narkewa. Rashin zafi, gabaɗaya, ya isa ya dumama mai narkewa zuwa yanayin zafi da ake buƙata. Kyakkyawan ƙarfin wutar lantarki daga ayyukan datti yana da iyaka - a Burtaniya, akwai kimanin 80 MW jimlar irin wannan ƙarni, tare da yiwuwar ƙaruwa zuwa 150 MW, wanda ba shi da mahimmanci idan aka kwatanta da matsakaicin ƙarfin da ake buƙata a Burtaniya na kimanin 35,000 MW. &nbsp;&nbsp;&nbsp;Yankin samar da iskar gas daga kwayoyin halitta marasa amfani - amfanin gona na makamashi, sharar abinci, da dai sauransu - ya fi girma, an kiyasta zai iya kimanin 3,000 MW. &nbsp;Tsire-tsire na iskar gas ta amfani da sharar dabbobi da albarkatun makamashi ana sa ran za su ba da gudummawa ga rage hayakin CO2 da ƙarfafa grid, yayin da suke ba da manoma na Burtaniya ƙarin kudaden shiga.

Wasu ƙasashe suna bada ƙarfafawa ta hanyar, alal misali, farashin ciyarwa don ciyar da wutar lantarki a kan wutar lantarki don tallafawa samar da makamashi mai kore.

A Oakland, California a babban tashar kula da ruwa mai guba ta East Bay Municipal Utility District (EBMUD), a halin yanzu ana sarrafa sharar abinci tare da ruwa mai tsabta na gari na farko da na biyu da sauran sharar gida masu ƙarfi. Idan aka kwatanta da narkewar ruwa mai guba na gari kadai, codigestion na sharar abinci yana da fa'idodi da yawa. Anaerobic narkewar abinci daga tsarin sharar abinci na EBMUD yana bada fa'idar makamashi mafi girma, idan aka kwatanta da ruwan sharar gida na gari: 730 zuwa 1,300 kWh a kowace tan bushe na sharar abinci da akayi amfani dashi idan aka kwatanta le 560 zuwa 940 kWh a kowane tan bushe na ruwan sharar gari da aka yi da shi.

### Injin grid
Injection na grid na biogas shine allurar biogas a cikin grid na gas. Dole ne a inganta ruwan da ba a yi amfani da shi ba zuwa biomethane. Wannan haɓakawa yana nufin cire gurɓataccen abu kamar hydrogen sulphide ko siloxanes, da kuma carbon dioxide. Akwai fasahohi dayawa don wannan dalili, wanda akafi aiwatar dashi shine matsa lamba (PSA), ruwa ko amine scrubbing (matakan shan ruwa) kuma, a cikin 'yan shekarun nan, rabuwa da membrane. A matsayin madadin, ana iya amfani da wutar lantarki da zafi don ƙarni a shafin,  wanda ke haifar da raguwar asarar jigilar makamashi. Rashin makamashi na yau da kullun a cikin tsarin watsa iskar gas ya kasance daga 1-2%, yayin da asarar makamashi a yanzu a kan babban tsarin lantarki ya kasance daga 5-8%.

A watan Oktoba na shekara ta 2010, Didcot Sewage Works yazama na farko a Burtaniya don samar da iskar gas da aka bayar ga grid na kasa, don amfani dashi har zuwa gidaje 200 a Oxfordshire. A shekara ta 2017, kamfanin wutar lantarki na Burtaniya Ecotricity ya shirya don samun digester da aka ciyar dashi ta hanyar ciyawa da aka samo a cikin gida  wanda ke ciyar da gidaje 6000 

### Man fetur na mota
Bayan ingantawa tare da fasahar da aka ambata a sama, ana iya amfani da biogas (wanda aka canza zuwa biomethane) azaman man fetur a cikin motocin da suka dace. Wannan amfani yana da yawa a Sweden, inda akwai motocin iskar gas sama da 38,600, kuma kashi 60% na iskar iskar iske ne wanda aka samar a cikin tsire-tsire masu narkewa.

### takin mai da kuma yanayin ƙasa
Za'a iya amfani da sashi mai ƙarfi, mai laushi na kayan da aka narke a matsayin mai yanayin ƙasa don ƙara abubuwan da ke cikin ƙasa. Ana iya amfani da ruwan inabi a matsayin taki don samar da muhimman abubuwan gina jiki ga ƙasa maimakon taki na sinadarai wanda ke buƙatar makamashi mai yawa don samarwa da jigilar kaya. Amfani da taki da aka ƙera, sabili da haka, ya fi ƙarfin carbon fiye da amfani da taki na giya na anaerobic digester. A cikin ƙasashe kamar Spain, inda ƙasa dayawa suka lalace, kasuwanni don abubuwa masu narkewa na iya zama daidai da mahimmanci kamar biogas.

### Gas na dafa abinci
Ta hanyar amfani da bio-digester, wanda ke samar da ƙwayoyin cuta da ake buƙata don lalacewa, ana samar da iskar dafa abinci. Sharar kwayoyin kamar ganye da suka fadi, sharar kicin, sharar abinci da dai sauransu ana ciyar dasu a cikin na'urar murkushewa, inda aka gauraya shi da karamin ruwa. Ana ciyar da cakuda a cikin bio-digester, inda archaea ke rushe shi don samar da iskar dafa abinci. Ana tura wannan iskar gas zuwa murhu na kicin. A 2 cubic mita bio-digester iya samar da 2 cubic meters na dafa abinci gas. Wannan daidai yake da 1 kg na LPG. &nbsp;Amfanin da akafi sani da amfani da bio-digester shine laka wanda yake da wadataccen turare.

## Kayayyakin
Manyan samfurori guda uku na narkewar anaerobic sune biogas, digestate, da ruwa.

### Magungunan halittu

 

Biogas shine mafi girman sharar gida na kwayoyin cuta dake ciyar da kayan abinci masu narkewa  (matakin methanogenesis na narkewar anaerobic ana yin sane ta hanyar archaea, wani micro-organism a kan wani reshe daban-daban na itacen phylogenetic na rayuwa zuwa kwayoyin cuti), kuma galibi methane ne da carbon dioxide,  tare da karamin adadin hydrogen da trace hydrogen sulfide.  (Kamar yadda aka samar, biogas kuma ya ƙunshi tururi na ruwa, tare da ƙarancin tururi na ruwan aiki na zafin jiki na biogas).  Yawancin iskar gas ana samar da ita a lokacin tsakiyar narkewa, bayan yawan ƙwayoyin cuta ya girma, kuma ya ragu yayin da kayan da zasu lalace ya ƙare. Ana adana iskar gas a saman digester a cikin kumfa mai iska ko cirewa kuma adanawa kusa da kayan aiki a cikin mai riƙe gas.

The methane in biogas can be burned to produce both heat and electricity, usually with a reciprocating engine or microturbine often in a cogeneration arrangement where the electricity and waste heat generated are used to warm the digesters or to heat buildings. Excess electricity can be sold to suppliers or put into the local grid. Electricity produced by anaerobic digesters is considered to be renewable energy and may attract subsidies. Biogas does not contribute to increasing atmospheric carbon dioxide concentrations because the gas is not released directly into the atmosphere and the carbon dioxide comes from an organic source with a short carbon cycle.

Biogas na iya buƙatar magani ko 'scrubbing' don tsaftace shi don amfani dashi azaman man fetur. Hydrogen sulfide, samfurin mai guba wanda aka kafa daga sulfates a cikin kayan abinci, an sake shi azaman sashi na biogas. Hukumomin tilasta muhalli na kasa, irin su Hukumar Kare Muhalli ta Amurka ko Hukumar Muhalli ta Ingilishi da Welsh, sun sanya takamaiman iyakoki a kan matakan iskar gas dake dauke da hydrogen sulfide, kuma, idan matakan hydrogen sulfides a cikin iskar gas suna da yawa, za a buƙaci tsabtace gas da kayan aiki (kamar maganin iskar amine) don aiwatar da iskar gas zuwa cikin matakan da aka yarda dasu a yankin. A madadin haka, ƙarin ferrous chloride FeCl2 zuwa tankunan narkewa yana hana samar da hydrogen sulfide.

Siloxanes masu saurin tashi na iya gurɓata iskar gas; ana samun irin waɗannan mahadi akai-akai a cikin sharar gida da ruwa mai guba. A cikin wuraren narkewa dake karɓar waɗannan kayan a matsayin wani bangare na kayan abinci, ƙananan nauyin kwayoyin siloxanes suna narkewa cikin iskar gas. Lokacin da aka ƙone wannan iskar gas a cikin injin gas, turbine, ko boiler, ana canza siloxanes zuwa silicon dioxide (SiO2), wanda ke ajiya a cikin na'ura, yana ƙara lalacewa da fashewa. Fasahar da ta dace da tsada don cire siloxanes da sauran gurɓataccen iskar gas suna samuwa a halin yanzu. A wasu aikace-aikace, ana iya amfani da magani *a wurin* don kara tsarkakar methane ta hanyar rage abubuwan dake cikin carbon dioxide, kawar da mafi yawansu a cikin na'urar nukiliya ta biyu.

A cikin ƙasashe kamar Switzerland, Jamus, da Sweden, ana iya matse methane a cikin iskar gas don ayi amfani dashi azaman man fetur na jigilar motoci ko shigarwa kai tsaye cikin iskar. A cikin ƙasashe inda direba don amfani da narkewar anaerobic shine tallafin wutar lantarki mai sabuntawa, wannan hanyar magani batada tabbas, kamar yadda ake buƙatar makamashi a wannan matakin sarrafawa kuma yana rage matakan da ake samu don siyarwa.

### Digestate
 
Digestate shine ragowar kayan shigarwa na asali ga digesters wanda microbes ba zasu iya amfani dashi ba. Har ila yau, ya ƙunshi ragowar ma'adanai na ƙwayoyin cuta da suka mutu daga cikin digesters. Digestate na iya zuwa cikin nau'o'i uku: fibrous, giya, ko haɗin laka na ɓangarorin biyu. A cikin tsarin matakai biyu, nau'o'i daban-daban na narkewa sun fito ne daga tankuna daban-daban. A cikin tsarin narkewa guda ɗaya, za'a haɗa ɓangarorin biyu kuma, idan ana so, a raba su ta hanyar ƙarin aiki.

Abu na biyu (acidogenic digestate) abu ne mai ɗorewa, kayan halitta wanda ya ƙunshi mafi yawa daga lignin da cellulose, amma kuma na nau'ikan ma'adanai iri-iri a cikin matrix na ƙwayoyin ƙwayoyin cuta masu mutuwa; wasu filastik na iya kasancewa. Kayan yayi kama da man fetur na cikin gida kuma ana iya amfani dashi kamar haka ko don yin samfuran gini masu ƙarancin gaske, kamar fiberboard.Hakanan ana iya amfani da sinadarin mai narkewa azaman kayan abinci don samar da ethanol.

Abu na uku shine ruwa (methanogenic digestate) mai wadata da abubuwan gina jiki, wanda za'a iya amfani dashi azaman taki, dangane da ingancin kayan da ake narkewa. Ya kamata a tantance matakan abubuwan dakee da guba (PTEs) ta hanyar sunadarai. Wannan zai dogara da ingancin kayan abinci na asali. Game da mafi yawan magudanan ruwa masu tsabta da kuma rarraba, matakan PTEs zasu kasance ƙasa. Game da sharar da ta samo asali daga masana'antu, matakan PTEs na iya zama mafi girma kuma za'a buƙaci ayi la'akari dasu yayin ƙayyade amfani mai dacewa don kayan.

Digestate yawanci yana ƙunshe da abubuwa, kamar lignin, waɗanda microorganisms na anaerobic bazasu iya karya su ba. Har ila yau, digestate na iya ƙunsar ammoniya wanda yake phytotoxic, kuma yana iya hana cigaban shuke-shuke idan anyi amfani dashi azaman kayan inganta ƙasa. Saboda wadannan dalilai guda biyu, ana iya amfani da matakin balaga ko composting bayan narkewa. Lignin da sauran kayan suna samuwa don lalacewa ta hanyar microorganisms na aerobic, kamar fungi, taimakawa rage yawan kayan don sufuri. A lokacin wannan balaga, ammoniya za'ayi amfani da ita a cikin nitrates, yana inganta yawan amfanin kayan kuma yana sa yafi dacewa a matsayin ingantaccen ƙasa. Ana amfani da manyan matakai na composting ta hanyar fasahar narkewar anaerobic.

### Ruwa mai guba
Sakamakon karshe daga tsarin narkewar anaerobic shine ruwa, wanda ya samo asali ne daga abun dake cikin danshi na asali wanda aka bi dashi da ruwa da aka samar yayin halayen microbial a cikin tsarin narkewa. Ana iya sakin wannan ruwa daga zubar da ruwa na digestate ko kuma yana iya zama ya rabu da digestate.

Ruwa mai guba wanda ke fita daga wurin narkewar anaerobic yawanci zai sami matakan da suka fi girma na Bukatar iskar oxygen (BOD) da buƙatar iskar sinadarai (COD). Wadannan matakan dake tattare da magudanar ruwa suna nuna ikon gurɓata. Wasu daga cikin wadannan kayan ana kiransu 'COD mai wuya', ma'ana baza'a iya samun damar kwayoyin cuta na anaerobic ba don juyawa zuwa biogas. Idan an sanya wannan ruwa kai tsaye a cikin ruwa, zai shafi su ta hanyar haifar da eutrophication. Saboda haka, ana buƙatar ƙarin magani na ruwa mai guba. Wannan magani yawanci zai zama mataki na oxidation inda iska ke wucewa ta cikin ruwa a cikin jerin batch reactors ko reverse osmosis unit.

## Tarihi

Rahoton sha'awar kimiyya a cikin masana'antar iskar gas da aka samar ta hanyar lalacewar kwayoyin halitta ya fito ne daga karni na 17, lokacin da Robert Boyle (a shekara ta 1627 zuwa shekarar 1691) da Stephen Hales (a shekara ta 1677 zuwa shekarar 1761) suka lura cewa tayar da turɓaya na rafi da tabkuna ya fitar da iskar gas mai cin wuta. A cikin shekara ta 1778, masanin kimiyyar Italiya Alessandro Volta (a shekara ta 1745 zuwa shekarar 1827), mahaifin electrochemistry,  ya gano wannan gas a matsayin methane.

A cikin shekarar 1808 Sir Humphry Davy ya tabbatar da kasancewar methane a cikin iskar gas da aka samar da naman shanu. An gina na farko da aka sani anaerobic digester a shekarar 1859 a wani mazaunin kuturta a Bombay a Indiya. A shekara ta 1895, an haɓaka fasahar a Exeter, Ingila, inda akayi amfani da tankin septic don samar da iskar gas don fitilar mai lalata iskar gas, wani nau'in Hasken gas. Har ila yau, a Ingila, a cikin shekarar 1904, an shigar da tanki na farko mai ma'ana biyu don maganin laka da laka a Hampton, London. 

A farkon karni na 20, tsarin narkewar anaerobic yafara kama da fasahar kamar yadda ta bayyana a yau. A cikin shekarar 1906, Karl Imhoff ya kirkiro tankin Imhoff;  wani nau'i na farko na anaerobic digester da tsarin maganin ruwa mai guba a farkon karni na 20.  Bayan shekarar 1920, tsarin tanki na rufe yafara maye gurbin amfani da aka saba amfani dashi a baya na lagoons anaerobic - wuraren da aka rufe da yumɓu da akayi amfani dasu don magance abubuwa masu ƙarfi. Bincike kan narkewar anaerobic yafara da gaske a cikin shekarun 1930.

A lokacin yakin duniya na, samarwa daga man fetur ya ragu yayin da samar da man fetur ta karu kuma an gano amfani da ita. Duk da yake karancin man fetur a lokacin yakin duniya na biyu ya sake inganta narkewar anaerobic, sha'awar fasahar ta sake raguwa bayan yakin ya ƙare. Hakazalika, rikicin makamashi na shekarar 1970 ya haifar da sha'awar narkewar anaerobic. Baya ga farashin makamashi mai yawa, abubuwan dake shafar karɓar tsarin narkewar anaerobic sun haɗa da karɓar kirkire-kirkire, azabtar da gurɓataccen yanayi, ƙarfafa manufofi, da wadatar tallafi da damar samun kuɗi.  

### Yankin zamani
A yau, ana samun anaerobic digesters tare da gonaki don rage nitrogen run-off daga turare, ko wuraren kula da ruwa mai guba don rage farashin zubar da laka. Anaerobic narkewar noma don samar da makamashi ya zama mafi mashahuri a Jamus, inda akwai masu narkewa 8,625 a cikin shekarar 2014.  A cikin Ƙasar Ingila, akwai wurare 259 a shekara ta 2014, kuma ayyukan 500 da aka shirya don fara aiki a shekara ta 2019. &nbsp;&nbsp;A Amurka, akwai tsire-tsire masu aiki 191 a fadin jihohi 34 a shekarar 2012.  Manufofin na iya bayyana dalilin da yasa yawan tallafi ya bambanta a duk faɗin waɗannan ƙasashe.

An kafa harajin ciyarwa a Jamus a cikin 1991, wanda akafi sani da FIT, yana bada kwangila na dogon lokaci wanda ke biyan saka hannun jari a cikin samar da makamashi mai sabuntawa. Sakamakon haka, tsakanin shekara ta 1991 da shekarar 1998 yawan tsire-tsire masu narkewa a Jamus yakaru daga 20 zuwa 517. A ƙarshen shekarun 1990s, farashin makamashi a Jamus ya bambanta kuma masu saka hannun jari basu da tabbacin damar kasuwa. Gwamnatin Jamus ta amsa ta hanyar yin gyare-gyare na FIT sau hudu tsakanin shekara ta 2000 da  shekarar 2011, kara farashin da inganta ribar narkewar anaerobic, kuma hakan ya haifar da dawowar da za'a iya dogara da ita don samar da iskar gas da cigaba da karɓar karɓa a duk faɗin ƙasar.

### Abubuwan da suka faru da suka shafi digesters
Anaerobic digesters sun haifar da kisan kifi (misali Kogin Mole, Devon,  Kogin Teifi,  Afon Llynfi,  da asarar rayuwar mutum (misali Fashewar Avonmouth) 

There have been explosions of Anaerobic Digesters in the US (Jay, Maine Pixelle Specialty Solutions' Androscoggin Mill; Pensacola (Cantonment) 22 January 2017 (Kamyr digester explosion); EPDM failure March 2013 Aumsville, Oregon; February 6, 1987, Pennsylvania two workers at a wastewater treatment plant were re-draining a sewage digester when an explosion lifted the 30-ton floating cover, killing both workers instantly; Southwest Wastewater Treatment Plant in Springfield, Missouri), in the UK (for example at Avonmouth and at Harper Adams College, Newport, Shropshire), plus In Europe, there were about 800 accidents on biogas plants between 2005 and 2015, e.g. in France (Saint-Fargeau) (though few of them were 'serious' with direct consequences for the human population). Fortunately, according to one source, 'less than a dozen of them had consequences on humans'- for example, the incident at Rhadereistedt, Germany (4 dead).

Binciken tsaro ya haɗa da   wani binciken shekarar 2016 ya tattara bayanan haɗari 169 da suka shafi ADs.

## Dubi kuma
 

## Manazarta

## Haɗin waje

* "Gidan yanar gizon hukuma na Anaerobic Digestion and Bioresources Association". Anaerobic Digestion and Bioresources Association (ADBA).
* "Gidan Bayanai na Ofishin Burtaniya kan Anaerobic Digestion da Biogas".
* "Majalisar Biogas ta Amurka". 9 ga Oktoba 2018.
* "Gabatarwa ga Biogas da Anaerobic Digestion], bayani daga Cibiyar Nazarin Muhalli ta Extension". An samo shi daga . .org/pages/Introduction_to_Biogas_and_Anaerobic_Digestion" rel="mw:ExtLink nofollow">asali a ranar 25 ga Disamba 2010. An samo shi a ranar 18 ga Nuwamba 2010.