JP2004059850A

JP2004059850A - Snow melter and its manufacturing process and method of decomposition of waste food

Info

Publication number: JP2004059850A
Application number: JP2002223172A
Authority: JP
Inventors: Hiroshi Yamauchi; 山内　寛
Original assignee: Hazama Gumi Ltd; Hazama Corp
Current assignee: Hazama Corp
Priority date: 2002-07-31
Filing date: 2002-07-31
Publication date: 2004-02-26

Abstract

<P>PROBLEM TO BE SOLVED: To provide an organic snow melter that has a better snow/ice melting effect and its persistence than the conventional organic snow melters, a low corrosivity against metal, concrete and the like and hardly destructs the environment. <P>SOLUTION: The snow melter contains the decomposition liquid of waste foods by microorganisms. Preferably it further contains sodium chloride, sodium formate and sodium acetate. The manufacturing process of the decomposition liquids of waste foods for use in the snow melter comprises adding 0.5-5 pts.mass of water to crushed waste foods, inoculating thermophylic microorganisms to the waste foods, decomposing it under an elevated temperature and aerobic condition and concentrating the resultant decomposition liquid. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は融雪剤及び融雪剤に使用される食品廃棄物の分解液の製造方法に関する。更に食品廃棄物の分解方法に関する。
【０００２】
【従来技術】
従来、道路等の融雪剤としては、主として塩化ナトリウム、塩化カルシウム等の塩素化合物が用いられてきた。しかし、これら塩素を含む融雪剤は腐食性が高く、鉄鋼やコンクリートなどの構造物、車両等の腐食を促進すること、あるいは沿道の街路樹等に悪影響を与えることなどの使用上の問題点が指摘されてきた。
【０００３】
このため、上記塩素化合物の使用上の問題を緩和することができる融雪剤として、酢酸塩、蟻酸塩または尿素などの有機化合物を主成分とする融雪剤が提供されている。しかしながら、このような融雪剤はかなり高価であり、このため使用し難いとの問題がある。
【０００４】
また、ビールなどの発酵食品製造過程やトウモロコシなど穀類の精製過程等で発生する、固形分を多量に含んだ廃液に塩素系化合物を添加して製造された融雪剤も提案されている（特開平１１−３５９２７号公報）。さらには廃糖蜜培養液に主として塩素系化合物を添加したもの（特開２００１−２７１０６０号公報）も提案されている。
【０００５】
【発明が解決しようとする課題】
廃棄物を有効活用した有機性融雪剤として、前記のようにビール廃液に塩素系化合物を添加したもの（特開平１１−３５９２７号公報）、さらには廃糖蜜培養液に主として塩素系化合物を添加したもの（特開２００１−２７１０６０号公報）が提案されているが、これらの融雪剤は固形分を多量に含むものであるため、道路等に散布し、散布後に融雪剤が乾燥した場合、道路上に固形状態となった融雪剤が散在することとなる。このような道路上を車両等が通行した場合、固形化した融雪剤が粉塵化するとの問題がある。
【０００６】
本発明は、従来の有機性融雪剤と比較して、融雪・融氷効果とその持続性に優れ、金属、コンクリート等に対する腐食性が低く、また環境に優しい融雪剤を提供することを目的とする。
【０００７】
また本発明は、上記融雪剤に使用される分解物を、悪臭の発生がなく、容易に製造することができる方法を提供することを目的とする。
【０００８】
さらに本発明は、食品廃棄物を容易に分解する方法を提供することを目的とする。
【０００９】
【課題を解決するための手段】
本発明者の検討によれば、食品廃棄物を主原料とし、微生物等を利用した簡易な分解過程により低分子の有機化合物を含む分解液を得ることができ、この分解液は融雪効果を有し、前記環境問題を引き起こさないことが分かった。
【００１０】
本発明は、食品廃棄物の分解液を含む融雪剤にある。
【００１１】
上記食品廃棄物の分解液が、微生物、特に好熱性微生物による分解液であることが好ましい。悪臭のほとんどない、効率の良い分解が可能となる。分解液の固形物は濾過等により除去されていることが一般的である。
【００１２】
本発明の融雪剤は、更に、ナトリウム化合物（特に、塩化ナトリウム、蟻酸ナトリウム、酢酸ナトリウム）を含むことが好ましい。融雪・融氷効果が向上する。
【００１３】
また本発明の融雪剤は、更に、塩素化合物（特に塩素化合物が、塩化ナトリウム、塩化カルシウム、塩化マグネシウム及び塩化カリウムから選ばれる少なくとも１種）を含むことが好ましい。融雪・融氷効果が向上する。
【００１４】
また本発明の融雪剤は、更に、脂肪族カルボン酸のアルカリ金属塩又はアルカリ土類金属塩（特に蟻酸ナトリウム又は酢酸ナトリウム）を含むことが好ましい。融雪・融氷効果が向上する。
【００１５】
食品廃棄物が、食堂調理残渣、食品工業加工残渣及び農業廃棄物から選ばれる少なくとも１種の廃棄物であることが好ましい。効率よく廃棄物を収集することができる。
【００１６】
前記のナトリウム化合物、塩素化合物、又は脂肪族カルボン酸のアルカリ金属塩又はアルカリ土類金属塩を、これらの化合物添加後の分解液に対して１０〜２５質量％含有させることが好ましい。
【００１７】
本発明は、本発明の前記融雪剤に用いられる食品廃棄物の分解物を製造する方法：即ち、食品廃棄物の破砕物に０．５〜５質量部の水を加え、４０〜９５℃の温度且つ好気性条件下において好熱性微生物を接種して分解反応に付し、得られた分解液を濃縮することを特徴とする食品廃棄物の分解物を製造する方法にもある。
【００１８】
上記温度が４５〜６５℃の範囲であることが好ましい。効率的に分解を行うことができる。好熱性微生物が好熱性細菌又は好熱性放線菌であることが好ましい。
【００１９】
本発明は、食品廃棄物の破砕物に０．５〜５質量部の水を加え、４５〜６５℃の範囲の好気性条件下において、好熱性細菌又は好熱性放線菌を接種して分解反応を行うことを特徴とする食品廃棄物の分解する方法にもある。
【００２０】
【発明の実施の態様】
前述の従来の有機性融雪剤は、有機性固形物を含むため、乾燥した融雪剤が散在する道路上を車両等が通行するため、融雪剤が粉塵化するとの問題があった。これに対して、本発明の融雪剤液は食品廃棄物破砕物を分解したのち、固形分をろ過等により除去した有機性液の濃縮物をそのまま、或いは好ましくはこれにナトリウム化合物、塩素化合物、脂肪族カルボン酸のアルカリ金属塩又はアルカリ土類金属塩を添加溶解して得られるものであり、これにより融雪・融氷効果、腐食性、環境破壊において大幅に改善されている。
【００２１】
本発明の融雪剤は、上記のように、食品廃棄物の分解液を含むものであり、好ましくはこれにナトリウム化合物、塩素化合物、脂肪族カルボン酸のアルカリ金属塩又はアルカリ土類金属塩を含有するものである。
【００２２】
本発明の融雪剤である有機性分解液は、さまざまな食品廃棄物、例えば食堂調理残渣や果実の搾りかす、おから、焼酎粕などの食品加工残渣又は野菜や果実などの農産廃棄物、或いは家庭の生ゴミ等を原料として、これらの破砕物に適量の水（一般に、食品廃棄物の５０〜５００質量％）を加え微生物を用いた分解処理により得られるものであり、糖類やアミノ酸、脂肪族カルボン酸等の有機酸、低級アルコールおよび無機塩などの低分子有機化合物を含有するものである。食品廃棄物は、１種類からなるものでも、複数種の混合物でも良い。また家庭の生ゴミ等も利用することもできる。
【００２３】
従って、本発明で用いる食品廃棄物の分解により得られる有機性分解液の組成等はその原料となる食品廃棄物の種類により異なり、一概に規定することはできない。しかしながら、実施例において示すように、数種類の食品廃棄物を原料として調製した有機性分解液の分析結果から、例えば、以下のような組成及び性状を有するものである。即ち、上記有機性分解液は、蒸発残留物２．０〜２５質量％、懸濁物質０．０２質量％（２００ｍｇ／Ｌ）以下、有機物炭素１．０〜１０質量％、全窒素０．０１〜１質量％、全リン０．０１〜０．１質量％、ナトリウム０．０１〜０．２質量％、カリウム０．２〜１質量％、塩素イオン０．２質量％以下、硫酸イオン０．２質量％以下を含み、一般に茶褐色を呈し、その粘度は比較的低めである。上記の内、融雪剤として有効な成分は蒸発残留物（主に比較的低分子の有機化合物と考えられる）と考えられる。分解液は水を一般に８０〜９５質量％含んでおり、他は通常有効成分である。上記の組成は単なる代表的な組成であり、上記物質の１種または複数が存在していなくとも、あるいは表記の項目以外の物質が含まれていても良いのは当然のことである。本発明の有機性分解液は、食品廃棄物を破砕した原料において見られる固形状態のものは、ほとんど見られず、従って、乾燥後に、粉塵となるような固形物をほとんど含まないものである。
【００２４】
また、食品廃棄物の分解は、一般に微生物による分解であるが、化学反応による分解であっても良い。微生物による分解処理の過程において、一般に、有機酸などさまざまな悪臭物質の生成を伴うことが多く、破砕スラリーの分解処理においては、作業環境の悪化や周辺への臭気拡散に配慮した対策が必要である。また、生成した分解液にも悪臭物質が含まれるため、これを利用する場合には然るべき設備における加熱脱臭処理等の実施が必要となる。
【００２５】
しかしながら、本発明の分解ではこのような悪臭の発生がほとんどない。即ち、本発明の微生物分解では、一般に約４０〜９５℃、好ましくは約４０〜７０℃、特に好ましくは約４５〜６５℃の温度において、分解槽に１分あたり原料スラリー（一般に、食品廃棄物及び水）体積相当量以上の空気を供給しながら、原料スラリーを一定速度以上で機械撹拌して、原料スラリーを好気性条件に保ち、中等度好熱菌を接種して分解を行うことにより、有機酸などの悪臭物質の生成を抑制しながら、効率的に炭水化物、タンパク質及び脂質などの高分子化合物を分解することを可能にしている。このとき、処理温度は特に５０〜６０℃程度が好ましく、通気量は概ね０．７５〜３．０ｖｖｍ（ｖｏｌｕｍｅ　ｐｅｒ　ｖｏｌｕｍｅ　ｐｅｒ　ｍｉｎｕｔｅ）が好ましく、さらに１〜２．５ｖｖｍに設定することが好ましい。また、機械撹拌は分解槽内の然るべき位置に２段以上に撹拌翼を備えることにより効率的に供給気体を拡散させながら行うことが好ましい。その撹拌速度を５０〜２００ｒｐｍ程度とすることが好ましく、さらに１００〜２００ｒｐｍとするのことが好ましい。
【００２６】
食品廃棄物の分解処理に用いる微生物は、一般に、土壌から分離した数株以上の好熱菌を混合したものである。好熱菌は、一般に４５〜６５℃までの温度範囲を生育の至適とする中等度好熱菌を用いるが、例えば、Ｂａｃｉｌｌｕｓ　ｓｔｅａｒｏｔｈｅｒｍｏ−ｐｈｉｌｕｓ　等の好熱性細菌、および好熱性の放線菌などを用いることが好ましい。またその植菌量は、食品廃棄物破砕スラリー原料（一般に、食品廃棄物及び水）への接種菌濃度で１０^９〜１０^１０セル／ｍｌ程度とするのが好ましい。植菌は、例えば、事前に適当な組成の液体培地に中等度好熱菌株を混合接種し、５５〜６０℃で一晩以上培養して菌濃度１０^１２セル／ｍｌ程度の菌液を調製し、これを原料スラリーに対してその体積の１／１００〜１／１０００量を加えて行われる。
【００２７】
有機性分解液は、既に有機性融雪剤としての効果を有するものであるが、さらにその融雪効果を増大させるために、特定の無機、有機化合物を添加することが好ましい。このような化合物としては、ナトリウム化合物、塩素化合物、脂肪族カルボン酸のアルカリ金属塩又はアルカリ土類金属塩を挙げることができる。塩素化合物としては、塩化ナトリウム、塩化カルシウム、塩化カリウム、塩化マグネシウム等を挙げることができる。また、脂肪族カルボン酸のアルカリ金属塩又はアルカリ土類金属塩としては、低級脂肪族カルボン酸（炭素原子数５個以下のものが好ましい；例、蟻酸、酢酸）のアルカリ金属塩又はアルカリ土類金属塩が好ましく、更に低級脂肪族カルボン酸のアルカリ金属塩、特に蟻酸ナトリウム又は酢酸ナトリウムが好ましい。これらの中でナトリウム化合物が好ましく、特に塩化ナトリウム、蟻酸ナトリウム又は酢酸ナトリウムが好ましい。上記化合物は単独で使用しても複数種組み合わせて使用しても良い。例えば、蟻酸ナトリウムと酢酸ナトリウムとの組み合わせの使用は単独よりも優れた効果を示す。
【００２８】
特に、塩化ナトリウム、蟻酸ナトリウム、酢酸ナトリウムのそれぞれ単独又は両化合物を添加溶解することにより、有機性分解液のみまたはこれらの化合物の水溶液のみを用いた場合と比較して、後述する実施例に示すように融雪効果およびその持続性において、相乗的な効果を得ることができる。これらの化合物の添加量は、これらの化合物添加後の有機性分解液に対して１０〜２５質量％であることが好ましく、特に１５〜２０質量％が好ましい。この場合の化合物添加前の有機性分解液は、蒸発残留物１５質量％含有液を基準とする。
【００２９】
この化合物添加による相乗効果の作用機構は明らかではないが、前記化合物が塩化ナトリウムの場合、添加による相乗効果の作用機構は、塩化ナトリウム由来の塩素とナトリウムに、有機性分解液に含まれる種々の低分子有機化合物およびカリウム等ナトリウム以外のアルカリ金属イオンなどの成分が加わることによりもたらされるものと推定される。
【００３０】
また、蟻酸ナトリウムおよび酢酸ナトリウムを使用する場合、それぞれ単独では１５〜２０質量％の濃度範囲、両化合物を加える場合はそれぞれ７．５〜１０質量％の濃度で添加することが好ましい（上記同様化合物添加後の分解液に対して）。この化合物添加による相乗効果の作用機構は明らかではないが、有機化合物由来の有機酸とナトリウムイオンに、有機性分解液に含まれる種々の低分子有機化合物およびカリウム等ナトリウム以外のアルカリ金属イオンなどの成分が加わることによりもたらされるものと推定される。
【００３１】
【実施例】
以下に本発明の実施例を示して詳しく説明する。また、特に断らない限り％は全て質量％を示す。
【００３２】
［実施例１］
食品廃棄物破砕物を低臭気で分解できる処理条件を確認する目的で、原料破砕物中の炭水化物含量を多めにし、有機酸生成を抑制可能な条件について検討した。
【００３３】
食パン破砕物１０４ｇ、魚肉片破砕物と鶏肉片破砕物それぞれ１３ｇ、計１３０ｇの模擬食堂調理残渣破砕物に、６５０ｍｌの水道水を加え、発酵槽容量２Ｌのミニジャーファーメンターを用いて４８時間６０℃に保って分解処理した。
【００３４】
機械撹拌は２段の撹拌翼を用いて行い、撹拌速度は１００ｒｐｍとし、予め、酵母エキス０．５％、ポリペプトン１％、ブドウ糖１％を含む液体培地を用いて５５℃で１晩培養した中等度好熱菌液を、原料スラリー８００ｍｌあたり８ｍｌ添加した。通気条件を４条件、それぞれ０．５ｖｖｍ、１．０ｖｖｍ、１．５ｖｖｍ、２．０ｖｖｍ、即ち約８００ｍｌの原料スラリーに対して１分あたり通気量を４００ｍｌから１６００ｍｌに設定し、各条件での有機酸の生成を、臭気官能試験及びスラリーのｐＨ推移から判定した。それぞれの分解条件でのスラリーのｐＨの推移、有機酸臭の有無等を表１にまとめて示す。
【００３５】
原料破砕物スラリーの初期ｐＨは５．８であり、原料破砕物を１１０℃、２４時間乾燥処理した結果、水分は３８．０質量％を示し、１３０ｇ破砕物のうち固形分は８０．６ｇ、固形物濃度は約１０質量％と算出された。４８時間分解処理後、いずれの条件も初期にみられた破砕固形物のかたまりはほとんど無くなっていた。
【００３６】
【表１】

【００３７】
上表において％は質量％を表す。
【００３８】
６０℃、撹拌下において、概ね１ｖｖｍ以上の通気を行えば、嫌気性で起きることが知られる有機酸の生成がほぼ抑えられ、かつ効率的な有機物分解が可能なことが確認された。
【００３９】
［実施例２］
リンゴ搾りかすを原料に高温好気条件で分解処理をして分解液を得、その加熱濃縮液に塩化ナトリウム又は有機酸塩を加えた試料液と、塩化ナトリウム又は有機酸塩の水溶液の融雪効果を、室内融氷試験（氷貫入試験）により比較した。
【００４０】
リンゴ搾りかすの破砕物５００ｇに水道水１０００ｍｌを加え、発酵槽容量２Ｌのミニジャーファーメンターを用いて、撹拌速度１００ｒｐｍ、通気量２ｖｖｍに設定し、中等度好熱菌培養液１５ｍｌを接種後、温度６０℃に維持して４８時間分解処理した。原料スラリーの初期ｐＨは４．４であった。原料スラリーの１１０℃、２４時間乾燥処理によって得られた含水率は７３．４質量％を示し、原料スラリーの総乾燥重量は１３８．０ｇ、固形物濃度は９質量％強と算出された。スラリーのｐＨ推移、発生臭などを表２に示す。
【００４１】
【表２】

【００４２】
上表において％は質量％を表す。
【００４３】
分解処理後のスラリーを遠心分離し、その上清をろ紙でろ過して分解液を得、これを約６倍に加熱濃縮したのち、析出した固形分をろ過して清澄な濃縮分解液を得た。この分解濃縮液に塩化ナトリウム又は有機酸塩を添加溶解した試料液と、脱イオン水に同一濃度の塩化ナトリウム又は有機酸塩を添加溶解した対照試料液を調製し、それぞれの簡易室内融氷試験における融氷効果とその持続性を比較した。また融氷試験は以下の方法により実施した。煮沸脱気した脱イオン水１０ｍｌ弱を蓋付きのポリプロピレン製容器（内径１４ｍｍ、高さ約１２ｃｍ）にいれ、予め所定の温度に設定したエタノール浴中で凍結させた。この氷供試体の上層に、必要に応じ微量のニュートラルレッド色素を加えた試料液または対照試料液を２ｍｌ加え、所定温度において一定時間後、氷供試体の融氷部の長さを測定した。−５℃および−１５℃における室内融氷試験の結果を、塩化ナトリウムについて表３−１、表３−２に、有機酸塩については表４−１、表４−２に示す。
【００４４】
【表３】

【００４５】
【表４】

【００４６】
［実施例３］
オレンジ搾りかすを原料に分解液を得、その加熱濃縮液に塩化ナトリウム又は有機酸塩を加えた試料液と塩化ナトリウム又は有機酸塩の融雪効果を、室内融氷試験（氷貫入試験）により比較した。
【００４７】
オレンジ搾りかすの破砕物５００ｇに水道水１０００ｍｌを加え、発酵槽容量２Ｌのミニジャーファーメンターを用いて、撹拌速度１００ｒｐｍ、通気量２ｖｖｍに設定し、中等度好熱菌培養液１５ｍｌを接種後、温度６０℃に維持して４８時間分解処理した。原料スラリーの初期ｐＨは４．２であった。原料スラリーの１１０℃、２４時間乾燥処理により得られた含水率は、８１．７質量％を示し、原料スラリーの総乾燥重量は９１．７ｇ、固形物濃度は６質量％強と算出された。スラリーのｐＨ推移、発生臭などを表５に示す。
【００４８】
【表５】

【００４９】
上表において％は質量％を表す。
【００５０】
解処理後のスラリーを遠心分離し、上清をろ紙でろ過して分解液を得、これを約６倍に加熱濃縮したのち、析出した固形分をろ過してほぼ清澄な濃縮分解液を得た。この分解濃縮液に塩化ナトリウム又は有機酸塩を添加溶解した試料液と、脱イオン水に同一濃度の塩化ナトリウム又は有機酸塩を添加溶解した対照試料液を調製し、それぞれの簡易室内融氷試験における融氷効果とその持続性を比較した。融氷試験の方法は実施例２と同一の方法である。−５℃および−１５℃における室内融氷試験の結果を、塩化ナトリウムについて表６−１、表６−２に、有機酸塩については表７−１、表７−２に示す。
【００５１】
【表６】

【００５２】
【表７】

【００５３】
［実施例４］
おからを原料に分解液を得、その加熱濃縮液に塩化ナトリウム又は有機酸塩を加えた試料液と塩化ナトリウム又は有機酸塩水溶液の融雪効果を、室内融氷試験（氷貫入試験）により比較した。
【００５４】
おから２５０ｇに水道水１０００ｍｌを加え、発酵槽容量２Ｌのミニジャーファーメンターを用いて、撹拌速度１００ｒｐｍ、通気量２ｖｖｍに設定し、中等度好熱菌培養液１２．５ｍｌを接種後、温度６０℃に維持して４８時間分解処理した。原料スラリーの初期ｐＨは７．２であった。原料スラリーの１１０℃、２４時間乾燥処理により得られた含水率は７８．６質量％を示し、原料スラリーの総乾燥重量は５３．４ｇ、固形物濃度は４質量％強と算出された。スラリーのｐＨ推移、発生臭などを表８に示す。
【００５５】
【表８】

【００５６】
上表において％は質量％を表す。
【００５７】
解処理後のスラリーを遠心分離し、上清をろ紙でろ過して分解液を得、これを約６倍に加熱濃縮したのち、析出した固形分をろ過して清澄な濃縮分解液を得た。この分解濃縮液に塩化ナトリウム又は有機酸塩を添加溶解した試料液と、脱イオン水に同一濃度の塩化ナトリウム又は有機酸塩を添加溶解した対照試料液を調製し、それぞれの簡易室内融氷試験における融氷効果とその持続性を比較した。融氷試験の方法は実施例２と同一の方法である。−５℃および−１５℃における室内融氷試験の結果を、塩化ナトリウムについて表９−１、表９−２に、有機酸塩については表１０−１、表１０−２に示す。
【００５８】
【表９】

【００５９】
【表１０】

【００６０】
［実施例５］
模擬食堂調理残渣破砕物を原料に分解液を得、その加熱濃縮液に塩化ナトリウム又は有機酸塩を加えた試料液と塩化ナトリウム又は有機酸塩水溶液の融雪効果を、室内融氷試験（氷貫入試験）により比較した。野菜屑３５０ｇ、米飯１００ｇ、魚肉片２５ｇ、鶏肉片２５ｇ、合計５００ｇの模擬食堂調理残渣破砕物に水道水１０００ｍｌを加え、発酵槽容量２Ｌのミニジャーファーメンターを用いて、撹拌速度１００ｒｐｍ、通気量２ｖｖｍに設定し、中等度好熱菌培養液１５ｍｌを接種後、温度６０℃に維持して４８時間分解処理した。原料スラリーの初期ｐＨは５．０であった。原料スラリーの１１０℃、２４時間乾燥処理によって得られた含水率は８７．４質量％を示し、原料スラリーの総乾燥重量は６３．２ｇ、固形物濃度約４質量％強と算出された。スラリーのｐＨ推移、発生臭などを表１１に示す。
【００６１】
０
【表１１】

【００６２】
解処理後のスラリーを遠心分離し、上清をろ紙でろ過して分解液を得、これを約４．８倍に加熱濃縮したのち、析出した固形分をろ過して清澄な濃縮分解液を得た。この分解濃縮液に塩化ナトリウム又は有機酸塩を添加溶解した試料液と、脱イオン水に同一濃度の塩化ナトリウム又は有機酸塩を添加溶解した対照試料液を調製し、それぞれの簡易室内融氷試験における融氷効果とその持続性を比較した。融氷試験の方法は実施例２と同一の方法である。−５℃および−１５℃における室内融氷試験の結果を、塩化ナトリウムについて表１２−１、表１２−２に、有機酸塩については表１３−１、表１３−２に示す。
【００６３】
【表１２】

【００６４】
【表１３】

【００６５】
得られた食品廃棄物分解液の組成分析例を表１４に示す。
【００６６】
【表１４】

【００６７】
上表において％は質量％を表す。
【００６８】
【発明の効果】
食品廃棄物は、一般に水分の含有率が高いため腐敗しやすく、さらに分解処理等で悪臭物質が発生しやすいことなどから、資源化処理と有効利用に課題を有するものである。本発明は、このような食品廃棄物を分解液状化して、融雪剤として有効利用したものである。更に、本発明で使用される食品廃棄物分解液は、鉄鋼等の金属、コンクリート等に対する腐食、植物等への影響が低く、従って本発明の融雪剤は環境破壊をほとんどもたらすことのない融雪剤ということができる。
【００６９】
さらに、食品廃棄物分解液に塩化ナトリウム、蟻酸或いは酢酸ナトリウム等の有機酸塩を添加することにより、融雪効果が格段に向上するので、このような組成の本発明の融雪剤は、環境破壊が少なく、優れた融雪効果を示すものである。特に、蟻酸或いは酢酸ナトリウム等の有機酸塩を用いた場合は、環境破壊は一層少なく環境に優しい融雪剤ということができる。
【００７０】
また、食品廃棄物分解液は常温での保存において腐敗などの変性がしばしば起きることが知られるが、一定濃度以上の塩化ナトリウム、蟻酸或いは酢酸ナトリウム等の有機酸塩の添加により、常温においても上記変性を受け難くなることから、高い保存性をも示すものである。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for producing a snow melting agent and a decomposition solution of food waste used for the snow melting agent. Furthermore, it relates to a method for decomposing food waste.
[0002]
[Prior art]
Conventionally, chlorine compounds such as sodium chloride and calcium chloride have been mainly used as snow melting agents for roads and the like. However, these snow-melting agents containing chlorine are highly corrosive, and have problems in use such as accelerating corrosion of structures such as steel and concrete, vehicles, and adversely affecting roadside street trees. It has been pointed out.
[0003]
For this reason, as a snow melting agent capable of alleviating the problem in using the chlorine compound, a snow melting agent mainly containing an organic compound such as acetate, formate or urea is provided. However, such snow melting agents are rather expensive, and therefore have the problem of being difficult to use.
[0004]
Further, a snow melting agent manufactured by adding a chlorine-based compound to a waste liquid containing a large amount of solids, which is generated in a process of producing fermented foods such as beer or a process of refining cereals such as corn, has also been proposed (JP-A-Hei. 11-35927). Further, a liquid molasses culture solution to which a chlorine compound is mainly added (Japanese Patent Application Laid-Open No. 2001-271060) has also been proposed.
[0005]
[Problems to be solved by the invention]
As an organic snow melting agent that effectively utilizes waste, a chlorine-based compound is added to beer waste liquid as described above (JP-A-11-35927), and a chlorine-based compound is mainly added to a molasses culture solution. However, since these snow-melting agents contain a large amount of solids, they are sprayed on a road or the like, and when the snow-melting agent is dried after the spraying, the solid is left on the road. The snow melting agent in the state is scattered. When a vehicle or the like passes on such a road, there is a problem that the solidified snow melting agent turns into dust.
[0006]
An object of the present invention is to provide a snow melting agent which is excellent in the snow melting / ice melting effect and its persistence, has low corrosiveness to metals and concrete, and is environmentally friendly as compared with conventional organic snow melting agents. I do.
[0007]
Another object of the present invention is to provide a method for easily producing a decomposed product used for the snow melting agent without generating offensive odor.
[0008]
Another object of the present invention is to provide a method for easily decomposing food waste.
[0009]
[Means for Solving the Problems]
According to the study of the present inventors, it is possible to obtain a decomposed solution containing low-molecular-weight organic compounds by using a food waste as a main raw material and performing a simple decomposition process using microorganisms and the like, and this decomposed solution has a snow melting effect. However, it was found that the above-mentioned environmental problems did not occur.
[0010]
The present invention resides in a snow melting agent containing a decomposition solution of food waste.
[0011]
It is preferable that the decomposed liquid of the food waste is a decomposed liquid of a microorganism, particularly a thermophilic microorganism. Efficient decomposition with almost no odor is possible. It is general that the solid matter of the decomposition liquid is removed by filtration or the like.
[0012]
The snow melting agent of the present invention preferably further contains a sodium compound (particularly, sodium chloride, sodium formate, sodium acetate). Snow melting / ice melting effect is improved.
[0013]
The snow melting agent of the present invention preferably further contains a chlorine compound (particularly, the chlorine compound is at least one selected from sodium chloride, calcium chloride, magnesium chloride, and potassium chloride). Snow melting / ice melting effect is improved.
[0014]
The snow melting agent of the present invention preferably further contains an alkali metal salt or an alkaline earth metal salt of an aliphatic carboxylic acid (particularly, sodium formate or sodium acetate). Snow melting / ice melting effect is improved.
[0015]
It is preferable that the food waste is at least one kind of waste selected from a canteen cooking residue, a food industry processing residue, and an agricultural waste. Waste can be collected efficiently.
[0016]
It is preferable that the alkali metal salt or the alkaline earth metal salt of the sodium compound, the chlorine compound, or the aliphatic carboxylic acid is contained in an amount of 10 to 25% by mass based on the decomposition solution after the addition of these compounds.
[0017]
The present invention provides a method for producing a decomposed product of food waste used for the snow melting agent of the present invention: that is, 0.5 to 5 parts by mass of water is added to a crushed food waste, and a temperature of 40 to 95 ° C. There is also a method for producing a decomposed product of food waste, which comprises inoculating a thermophilic microorganism under a temperature and aerobic condition and subjecting it to a decomposition reaction, and concentrating the obtained decomposed liquid.
[0018]
It is preferable that the temperature be in the range of 45 to 65 ° C. Decomposition can be performed efficiently. Preferably, the thermophilic microorganism is a thermophilic bacterium or a thermophilic actinomycete.
[0019]
The present invention provides a decomposition reaction by adding 0.5 to 5 parts by mass of water to a crushed food waste and inoculating a thermophilic bacterium or a thermophilic actinomycete under an aerobic condition in a range of 45 to 65 ° C. There is also a method for decomposing food waste, which is characterized by performing the following.
[0020]
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The above-mentioned conventional organic snow melting agent contains an organic solid, so that a vehicle or the like passes on a road on which the dried snow melting agent is scattered, so that there is a problem that the snow melting agent becomes dusty. On the other hand, the snow-melting agent liquid of the present invention decomposes the crushed food waste, and then removes the solid content by filtration or the like to obtain the organic liquid concentrate as it is, or preferably to a sodium compound, a chlorine compound, It is obtained by adding and dissolving an alkali metal salt or an alkaline earth metal salt of an aliphatic carboxylic acid, thereby greatly improving the snow melting / ice melting effect, corrosiveness, and environmental destruction.
[0021]
As described above, the snow melting agent of the present invention contains a decomposition solution of food waste, and preferably contains a sodium compound, a chlorine compound, an alkali metal salt or an alkaline earth metal salt of an aliphatic carboxylic acid. Is what you do.
[0022]
The organic decomposition solution that is the snow melting agent of the present invention is various food wastes, for example, canteen cooking residues and fruit pomace, okara, food processing residues such as shochu lees or agricultural wastes such as vegetables and fruits, or It is obtained by adding a suitable amount of water (generally, 50 to 500% by mass of food waste) to these crushed products using household garbage and the like as raw materials, and is obtained by a decomposition treatment using microorganisms. It contains an organic acid such as an aromatic carboxylic acid and a low molecular weight organic compound such as a lower alcohol and an inorganic salt. The food waste may consist of one type or a mixture of a plurality of types. Also, household garbage and the like can be used.
[0023]
Therefore, the composition and the like of the organic decomposition solution obtained by decomposing the food waste used in the present invention differs depending on the type of the food waste used as the raw material, and cannot be specified unconditionally. However, as shown in the examples, from the analysis results of the organic decomposition liquid prepared using several types of food waste as raw materials, for example, it has the following composition and properties. That is, the organic decomposition solution contains 2.0 to 25% by mass of an evaporation residue, 0.02% by mass or less (200 mg / L) of a suspended substance, 1.0 to 10% by mass of organic carbon, and 0.01% of total nitrogen. To 1% by mass, total phosphorus 0.01 to 0.1% by mass, sodium 0.01 to 0.2% by mass, potassium 0.2 to 1% by mass, chloride ion 0.2% by mass or less, sulfate ion 0.1%. It contains 2% by mass or less, generally shows a brown color, and its viscosity is relatively low. Among the above, the components effective as snow melting agents are considered to be evaporation residues (mainly considered to be relatively low molecular organic compounds). The decomposed liquid generally contains 80 to 95% by mass of water, and the others are usually active ingredients. The above-mentioned composition is merely a typical composition, and it goes without saying that one or more of the above-mentioned substances may not be present, or a substance other than the listed items may be contained. The organic decomposition solution of the present invention hardly shows a solid state found in a raw material obtained by crushing food waste, and therefore contains almost no solid matter that becomes dust after drying.
[0024]
Decomposition of food waste is generally performed by microorganisms, but may be performed by chemical reaction. In the process of decomposition by microorganisms, in general, various malodorous substances such as organic acids are often generated, and when decomposing crushed slurry, it is necessary to take measures that consider the deterioration of the working environment and the diffusion of odor to the surroundings. is there. Further, since the generated decomposed liquid also contains a malodorous substance, when this is used, it is necessary to perform a heat deodorizing treatment or the like in an appropriate facility.
[0025]
However, the decomposition according to the present invention hardly generates such a bad odor. That is, in the microbial decomposition of the present invention, the raw material slurry (generally, food waste) per minute is generally added to the decomposition tank at a temperature of about 40 to 95 ° C, preferably about 40 to 70 ° C, and particularly preferably about 45 to 65 ° C. And water) by mechanically stirring the raw material slurry at a certain speed or higher while supplying air at a volume equivalent or more, maintaining the raw material slurry under aerobic conditions, inoculating moderate thermophilic bacteria to perform decomposition, This makes it possible to efficiently decompose high-molecular compounds such as carbohydrates, proteins and lipids while suppressing generation of malodorous substances such as organic acids. At this time, the treatment temperature is particularly preferably about 50 to 60 ° C., and the ventilation rate is preferably about 0.75 to 3.0 vvm (volume per volume per minute), and more preferably 1 to 2.5 vvm. Further, it is preferable that mechanical stirring is performed while efficiently diffusing the supplied gas by providing two or more stages of stirring blades at appropriate positions in the decomposition tank. The stirring speed is preferably about 50 to 200 rpm, and more preferably 100 to 200 rpm.
[0026]
Microorganisms used for the decomposition treatment of food waste are generally a mixture of several or more thermophilic bacteria isolated from soil. As the thermophilic bacterium, a moderately thermophilic bacterium that generally grows in a temperature range of 45 to 65 ° C. is used. For example, a thermophilic bacterium such as Bacillus stearothermo-philus , and a thermophilic bacterium such as a thermophilic bacterium are used. Preferably, it is used. The inoculation amount is preferably about 10 ⁹ to 10 ¹⁰ cells / ml in terms of the inoculum concentration of the food waste crushed slurry raw material (generally, food waste and water). For inoculation, for example, a medium thermophilic strain is mixed and inoculated in advance in a liquid medium having an appropriate composition, and cultured at 55 to 60 ° C overnight or more to prepare a bacterial solution having a bacterial concentration of about 10 ¹² cells / ml. This is performed by adding 1/100 to 1/1000 of the volume to the raw slurry.
[0027]
The organic decomposition solution already has an effect as an organic snow melting agent, but it is preferable to add a specific inorganic or organic compound in order to further increase the snow melting effect. Examples of such a compound include a sodium compound, a chlorine compound, and an alkali metal salt or an alkaline earth metal salt of an aliphatic carboxylic acid. Examples of the chlorine compound include sodium chloride, calcium chloride, potassium chloride, magnesium chloride and the like. As the alkali metal salt or alkaline earth metal salt of an aliphatic carboxylic acid, an alkali metal salt or alkaline earth metal of a lower aliphatic carboxylic acid (having 5 or less carbon atoms; for example, formic acid, acetic acid) is preferable. Metal salts are preferred, more preferably alkali metal salts of lower aliphatic carboxylic acids, especially sodium formate or sodium acetate. Of these, sodium compounds are preferred, and sodium chloride, sodium formate or sodium acetate is particularly preferred. The above compounds may be used alone or in combination of two or more. For example, the use of a combination of sodium formate and sodium acetate is more effective than alone.
[0028]
In particular, sodium chloride, sodium formate, and sodium acetate each alone or by adding and dissolving both compounds, as compared to the case of using only the organic decomposition solution or only the aqueous solution of these compounds, will be described in Examples described later. Thus, a synergistic effect can be obtained in the snow melting effect and its persistence. The addition amount of these compounds is preferably from 10 to 25% by mass, and particularly preferably from 15 to 20% by mass, based on the organic decomposition solution after the addition of these compounds. In this case, the organic decomposition solution before the addition of the compound is based on a solution containing 15% by mass of the evaporation residue.
[0029]
Although the mechanism of action of the synergistic effect due to the addition of the compound is not clear, when the compound is sodium chloride, the mechanism of action of the synergistic effect by the addition is various types of chlorine and sodium derived from sodium chloride contained in the organic decomposition solution. It is presumed to be caused by the addition of components such as low molecular organic compounds and alkali metal ions other than sodium such as potassium.
[0030]
Further, when sodium formate and sodium acetate are used, it is preferable that each of them is added alone at a concentration range of 15 to 20% by mass, and when both compounds are added, each is added at a concentration of 7.5 to 10% by mass (similar to the compound described above). To the decomposition solution after addition). Although the mechanism of action of the synergistic effect due to the addition of this compound is not clear, the organic acid derived from the organic compound and sodium ions are added to various low-molecular organic compounds contained in the organic decomposition solution and alkali metal ions other than sodium such as potassium. It is presumed to result from the addition of the components.
[0031]
【Example】
Hereinafter, embodiments of the present invention will be described in detail. Unless otherwise specified, all percentages indicate mass%.
[0032]
[Example 1]
In order to confirm the treatment conditions that can decompose the crushed food waste with low odor, we examined the conditions that can increase the carbohydrate content in the crushed raw material and suppress the production of organic acids.
[0033]
To a total of 130 g of the simulated cafeteria cooking residue crushed material of 104 g of the crushed bread material, 13 g of the crushed fish meat material and the crushed chicken meat material, and 130 g in total, 650 ml of tap water was added, and the mixture was fermented for 2 hours using a mini-jar fermenter having a 2 L fermenter capacity. Decomposition treatment was carried out at a temperature of ° C.
[0034]
Mechanical stirring is performed using a two-stage stirring blade, the stirring speed is set to 100 rpm, and the medium is previously cultured overnight at 55 ° C. using a liquid medium containing 0.5% yeast extract, 1% polypeptone, and 1% glucose. The thermophilic bacterium solution was added in an amount of 8 ml per 800 ml of the raw material slurry. The ventilation conditions were set to four conditions, 0.5 vvm, 1.0 vvm, 1.5 vvm, and 2.0 vvm, that is, the ventilation amount per minute was set from 400 ml to 1600 ml for a raw material slurry of about 800 ml, and the organic under each condition was set. The generation of acid was determined from the odor sensory test and the pH change of the slurry. Table 1 summarizes the transition of the pH of the slurry and the presence or absence of organic acid odor under each decomposition condition.
[0035]
The initial pH of the raw material crushed slurry was 5.8, and the raw material crushed material was dried at 110 ° C. for 24 hours. As a result, the water content was 38.0% by mass, and the solid content of the 130 g crushed material was 80.6 g, The solids concentration was calculated to be about 10% by weight. After the decomposition treatment for 48 hours, the crushed solid mass observed at the initial stage was almost eliminated under any conditions.
[0036]
[Table 1]

[0037]
In the above table,% represents mass%.
[0038]
It was confirmed that, when aeration at about 1 vvm or more was performed under stirring at 60 ° C., the generation of organic acids, which are known to occur anaerobically, was almost suppressed, and efficient decomposition of organic substances was possible.
[0039]
[Example 2]
Decomposition of apple pomace as a raw material under high temperature and aerobic conditions to obtain a decomposed liquid, and a snow melting effect of a sample liquid obtained by adding sodium chloride or an organic acid salt to the heat concentrated liquid and an aqueous solution of sodium chloride or an organic acid salt Were compared by a laboratory ice melting test (ice penetration test).
[0040]
1000 ml of tap water is added to 500 g of the crushed apple pomace, and using a mini-jar fermenter with a fermenter capacity of 2 L, the stirring speed is set to 100 rpm and the aeration rate is 2 vvm. After inoculating 15 ml of the medium thermophilic bacterium, Decomposition treatment was performed for 48 hours while maintaining the temperature at 60 ° C. The initial pH of the raw slurry was 4.4. The water content of the raw material slurry obtained by drying at 110 ° C. for 24 hours was 73.4% by mass, the total dry weight of the raw material slurry was 138.0 g, and the solid concentration was calculated to be slightly more than 9% by mass. Table 2 shows the pH change of the slurry, the generated odor, and the like.
[0041]
[Table 2]

[0042]
In the above table,% represents mass%.
[0043]
The slurry after the decomposition treatment is centrifuged, and the supernatant is filtered through a filter paper to obtain a decomposition solution, which is heated and concentrated about 6 times, and then the precipitated solid is filtered to obtain a clear concentrated decomposition solution. Was. Prepare a sample solution prepared by adding sodium chloride or an organic acid salt to this decomposed concentrated solution, and a control sample solution prepared by adding sodium chloride or an organic acid salt of the same concentration to deionized water. The effect of ice melting and its persistence were compared. The ice melting test was performed by the following method. A little less than 10 ml of boiling degassed deionized water was placed in a polypropylene container (inner diameter: 14 mm, height: about 12 cm) with a lid, and frozen in an ethanol bath set at a predetermined temperature in advance. To the upper layer of the ice sample, 2 ml of a sample solution or a control sample solution to which a trace amount of neutral red dye was added as necessary was added, and after a certain period of time at a predetermined temperature, the length of the melted ice portion of the ice sample was measured. The results of the indoor ice melting test at -5 ° C and -15 ° C are shown in Tables 3-1 and 3-2 for sodium chloride, and Tables 4-1 and 4-2 for organic acid salts.
[0044]
[Table 3]

[0045]
[Table 4]

[0046]
[Example 3]
Decomposition liquid obtained from orange pomace as raw material, and comparison of the snow melting effect of sodium chloride or organic acid salt with a sample solution obtained by adding sodium chloride or organic acid salt to the heated concentrated liquid by indoor ice melting test (ice penetration test) did.
[0047]
After adding 1000 ml of tap water to 500 g of the orange pomace crushed product, using a mini-jar fermenter with a fermenter capacity of 2 L, setting the stirring speed at 100 rpm and the aeration rate at 2 vvm, and inoculating 15 ml of the medium thermophilic bacterium, Decomposition treatment was performed for 48 hours while maintaining the temperature at 60 ° C. The initial pH of the raw slurry was 4.2. The moisture content of the raw material slurry obtained by drying at 110 ° C. for 24 hours was 81.7% by mass, the total dry weight of the raw material slurry was 91.7 g, and the solid concentration was calculated to be slightly more than 6% by mass. Table 5 shows the pH transition of the slurry, the generated odor, and the like.
[0048]
[Table 5]

[0049]
In the above table,% represents mass%.
[0050]
The slurry after the disintegration treatment is centrifuged, and the supernatant is filtered with filter paper to obtain a decomposed solution, which is heated and concentrated about 6 times, and then the precipitated solid is filtered to obtain a substantially clear concentrated decomposed solution. Was. Prepare a sample solution prepared by adding sodium chloride or an organic acid salt to this decomposed concentrated solution, and a control sample solution prepared by adding sodium chloride or an organic acid salt of the same concentration to deionized water. The effect of ice melting and its persistence were compared. The method of the ice melting test is the same as that in Example 2. The results of the indoor ice melting test at -5 ° C and -15 ° C are shown in Tables 6-1 and 6-2 for sodium chloride, and Tables 7-1 and 7-2 for organic acid salts.
[0051]
[Table 6]

[0052]
[Table 7]

[0053]
[Example 4]
Decomposition liquid is obtained from okara as raw material, and the snow melting effect of a sample liquid obtained by adding sodium chloride or organic acid salt to the heated concentrated liquid and the aqueous solution of sodium chloride or organic acid salt is compared by the indoor ice melting test (ice penetration test). did.
[0054]
After adding 1000 ml of tap water to 250 g of okara, using a mini-jar fermenter having a fermenter capacity of 2 L, the stirring speed was set to 100 rpm and the aeration rate was 2 vvm, and after inoculating 12.5 ml of the medium thermophilic bacterium, the temperature was increased to 60%. Decomposition treatment was performed for 48 hours while maintaining the temperature at ° C. The initial pH of the raw slurry was 7.2. The water content of the raw material slurry obtained by drying at 110 ° C. for 24 hours was 78.6% by mass, the total dry weight of the raw material slurry was 53.4 g, and the solid concentration was calculated to be slightly more than 4% by mass. Table 8 shows the pH change of the slurry, the generated odor, and the like.
[0055]
[Table 8]

[0056]
In the above table,% represents mass%.
[0057]
The slurry after the disintegration treatment was centrifuged, and the supernatant was filtered with filter paper to obtain a decomposed solution, which was concentrated by heating about 6 times, and then the precipitated solid was filtered to obtain a clear concentrated decomposed solution. . Prepare a sample solution prepared by adding sodium chloride or an organic acid salt to this decomposed concentrated solution, and a control sample solution prepared by adding sodium chloride or an organic acid salt of the same concentration to deionized water. The effect of ice melting and its persistence were compared. The method of the ice melting test is the same as that in Example 2. The results of the indoor ice melting test at -5 ° C and -15 ° C are shown in Tables 9-1 and 9-2 for sodium chloride, and Tables 10-1 and 10-2 for organic acid salts.
[0058]
[Table 9]

[0059]
[Table 10]

[0060]
[Example 5]
A decomposed liquid was obtained from the crushed food from the cooking residue of the simulated cafeteria, and the snow melting effect of a sample solution obtained by adding sodium chloride or an organic acid salt to the heated concentrated liquid and an aqueous solution of sodium chloride or an organic acid salt was determined by the indoor ice melting test Test). 1000 ml of tap water is added to a total of 500 g of the simulated canteen cooking residue crushed material of 350 g of vegetable waste, 100 g of cooked rice, 25 g of fish meat, and 25 g of chicken meat, and a stirring speed of 100 rpm using a mini-jar fermenter having a fermenter capacity of 2 L and aeration rate. After inoculating 15 ml of the medium containing the thermophilic bacterium at 2 vvm, the digestion treatment was carried out for 48 hours while maintaining the temperature at 60 ° C. The initial pH of the raw slurry was 5.0. The water content of the raw material slurry obtained by drying at 110 ° C. for 24 hours was 87.4% by mass, and the total dry weight of the raw material slurry was calculated to be 63.2 g, and the solid concentration was about 4% by mass or more. Table 11 shows the change in pH of the slurry, the generated odor, and the like.
[0061]
0
[Table 11]

[0062]
The slurry after the disintegration treatment is centrifuged, and the supernatant is filtered through filter paper to obtain a decomposed solution, which is concentrated by heating about 4.8 times, and then the precipitated solid is filtered to obtain a clear concentrated decomposed solution. Obtained. Prepare a sample solution prepared by adding sodium chloride or an organic acid salt to this decomposed concentrated solution, and a control sample solution prepared by adding sodium chloride or an organic acid salt of the same concentration to deionized water. The effect of ice melting and its persistence were compared. The method of the ice melting test is the same as that in Example 2. The results of the indoor ice melting test at -5 ° C and -15 ° C are shown in Tables 12-1 and 12-2 for sodium chloride, and Tables 13-1 and 13-2 for organic acid salts.
[0063]
[Table 12]

[0064]
[Table 13]

[0065]
Table 14 shows composition analysis examples of the obtained food waste decomposition solution.
[0066]
[Table 14]

[0067]
In the above table,% represents mass%.
[0068]
【The invention's effect】
Food waste generally has a high water content and thus easily rots, and furthermore, odorous substances are liable to be generated by a decomposition treatment or the like. In the present invention, such food waste is decomposed and liquefied, and is effectively used as a snow melting agent. Furthermore, the food waste decomposition solution used in the present invention has a low effect on corrosion of metals such as steel, concrete and the like, and on plants and the like. Therefore, the snow melting agent of the present invention hardly causes environmental destruction. It can be said.
[0069]
Furthermore, by adding an organic acid salt such as sodium chloride, formic acid or sodium acetate to the food waste decomposition solution, the snow melting effect is remarkably improved. It shows little and excellent snow melting effect. In particular, when an organic acid salt such as formic acid or sodium acetate is used, it can be said that it is an environmentally friendly snow melting agent with less environmental destruction.
[0070]
Also, it is known that degradation of food waste decomposed liquid often occurs during storage at room temperature, such as spoilage.However, addition of an organic acid salt such as sodium chloride, formic acid, or sodium acetate at a certain concentration or higher may cause the above-mentioned degradation at room temperature. Since they are less susceptible to denaturation, they also exhibit high storage stability.

Claims

Snow melting agent containing decomposed liquid of food waste.

The snow melting agent according to claim 1, wherein the decomposition solution of the food waste is a decomposition solution of a microorganism.

The snow melting agent according to claim 2, wherein the microorganism is a thermophilic microorganism.

The snow melting agent according to claim 1, further comprising a sodium compound.

The snow melting agent according to claim 4, wherein the sodium compound is sodium chloride, sodium formate, or sodium acetate.

The snow melting agent according to claim 1, further comprising a chlorine compound.

The snow melting agent according to claim 6, wherein the chlorine compound is at least one selected from sodium chloride, calcium chloride, magnesium chloride, and potassium chloride.

The snow melting agent according to any one of claims 1 to 3, further comprising an alkali metal salt or an alkaline earth metal salt of an aliphatic carboxylic acid.

The snow melting agent according to claim 8, wherein the alkali metal salt of the aliphatic carboxylic acid is sodium formate or sodium acetate.

The snow melting agent according to any one of claims 1 to 9, wherein the food waste is at least one kind of waste selected from canteen cooking residues, food industry processing residues, and agricultural wastes.

The alkali metal salt or alkaline earth metal salt of a sodium compound, a chlorine compound, or an aliphatic carboxylic acid is contained in an amount of 10 to 25% by mass based on the decomposition solution after the addition of these compounds. The described snow melting agent.

0.5 to 5 parts by mass of water is added to the crushed food waste, and a thermophilic microorganism is inoculated at a temperature of 40 to 95 ° C. under aerobic conditions to cause a decomposition reaction, and the obtained decomposition solution is concentrated. A method for producing a decomposed product of food waste used for a snow melting agent according to any one of claims 1 to 10.

13. The method according to claim 12, wherein said temperature is in the range of 45-65 <0> C.

The method according to claim 12 or 13, wherein the thermophilic microorganism is a thermophilic bacterium or a thermophilic actinomycete.

0.5 to 5 parts by mass of water is added to the crushed food waste, and a thermophilic bacterium or a thermophilic actinomycete is inoculated under aerobic conditions at a temperature of 45 to 65 ° C. to cause a decomposition reaction. The method of decomposing food waste.