【０００１】
【産業上の利用分野】
本発明は工業用若しくは商業用或いは宅地用としての土地造成に際して、客土若しくは切土が汚染されていても、或いは造成土地の使用に伴い汚染物質が飛散付着若しくは放散付着し汚染された場合でも、汚染物質を浄化しえる土地の浄化造成方法に関するものである。
【０００２】
【従来技術】
我が国では経済成長とともに産業規模も著しく拡大化し、これにより多量の煤煙の排出を初め産業廃水や産業廃棄物が排出され続けており、而も化学工業の発達に伴い多量の重金属類や化学薬品、有機化合物等が工業用はもとより家庭用品としても多用されてきたため、土壌や水、空気に至るまで極度に汚染された状態となり、加えて自動車社会化に伴う膨大量の排気ガスの排出とも相俟って、これらを原因とする疾病が各地で多発しており、環境浄化が国際的にも国内的にも緊急課題とされている。
【０００３】
ところで土壌においては、重金属類や化学薬品、有機化合物等の汚染物質が付着し若しくは放散されて浸透すると地中内部に拡散され且蓄積されるとともに、自浄作用が働かぬため時間経過とともに益々高濃度に汚染されてゆく特質を持っている。
而も従来まで土地は高い財産的価値が認められてなるため、企業はもとより個人に至るまで投資若しくは投機がなされてきたものの、現在に至っては汚染土地の評価見直しが進められつつあるため、既利用の土地の浄化はもとより造成土地においての浄化は不可避の問題とされている。
【０００４】
これがため切土による盛土造成或いは客土による客土造成においても、造成する土地の汚染に加え盛土や客土自体も汚染されている場合も多く、従って造成に際しては造成地自体を現位置で浄化し且盛土や客土も浄化処理を行う必要がある。
而しながら都市部や都市近郊では、盛土や客土の浄化処理のためのスペースや処理設備の設置も至難であるため、採掘した盛土や客土を一旦郊外の処理場所まで搬送し、洗浄等の浄化処理を施したうえ造成地まで再搬送させねばならず、浄化費用に加えて莫大な搬送費用が強いられ、且仮令かかる浄化処理が施された盛土や客土で盛土造成若しくは客土造成がなされたうえ利用に供された場合には、その利用経過とともに再び汚染物質が飛散付着し或いは放散付着浸透して汚染が増長される結果となる。
【０００５】
そこで造成地の原位置における浄化方法としては、ボーリングにより地下水面より上の不飽和帯に吸引井戸を設置し、真空ポンプやブロアーで減圧して汚染物質の蒸気を吸引し且汚染物質の蒸気を活性炭で吸着除去し若しくは紫外線で酸化分解させる土壌ガス吸引法を初め、複数の円柱状にボーリング掘削後、土壌中の特殊セメント等の不溶化、固化剤を注入する固化、不溶化方法、Ａ重油汚染土を珪酸ナトリウム水溶液中に流動させて洗浄する土壌洗浄方法、鉄粉による六価クロムの還元安定化を図る還元処理方法、或いは土壌中に電極を挿入してイオン性の汚染物質を移動後分解する電気的分離方法等が公知されている。
【０００６】
然るにこれら方法は比較的大型な設備に加えて高度の技術が要請され、且そのコストも莫大となることにより、特別な予算措置等が講ぜられぬ限り実用使用には至らず、現状においては実用化された結果も見聞されていない。
更に土地造成に際しては、盛土造成でも客土造成においても十分な締固による強固安定した地盤として造成することが望まれるものの、他方造成される地盤は原野や湿地、農地或いは河川や湖沼近傍等も比較的多く、特に水分の多い粘土質や泥質の地質では単に切土の盛土造成若しくは客土による客土造成では極めて多量の盛土や客土による埋設が強いられるとともに、造成に際しての締固めも不十分となり不等沈下が招来され、再々に亘って補修造成を余儀なくされる問題も内在する。
【０００７】
発明者はかかる問題に鑑み研究を重ねた結果、近年に至ってその残留主成分が酸化珪素及び酸化アルミニウムからなる産業廃棄物、特には石炭焼却灰をアルカリ前処理と高温高圧処理により微粒状で且膨大量の微細孔隙を有する人工ゼオライト粉体が量産化可能となったこと、並びに該人工ゼオライト粉体は本質的に調湿作用及び触媒作用を保持するとともに、広範囲の粒径と吸水吸着容量に係る比表面積或いは汚染物質の吸着固定若しくは吸着分解消去に係る塩基置換性、所謂塩基置換容量（ｍｅｑ／１００ｇ）も広範囲に付与せしめることが可能となること、及び該人工ゼオライト粉体の吸水性や吸着性を阻害させることなく且織物や編物若しくは不織布等に所要の塗着重量割合で、而も透水性を保持するよう塗着させたうえ盛土造成若しくは客土造成に際して、その造成底面及び造成する客土内若しくは盛土内の適宜部位に敷設せしめることにより、汚染土壌の浄化と不等沈下を阻止しえる造成が可能となることを究明し本発明に至った。
【０００８】
【発明が解決しようとする課題】
本発明は土地を掘削のうえ客土造成し若しくは切土により盛土造成する土地の造成において、客土や盛土が汚染された状態でも長期に亘って浄化でき且不等沈下をも防止しえる造成の可能な土地の浄化造成方法を提供することにある。
【０００９】
【課題を解決するための手段】
上述の課題を解決するために本発明が用いた技術的手段は、土地を所要の深さに掘削のうえ客土により造成し、若しくは切土により所要の高さに盛土し造成する場合に、造成底面と客土内若しくは盛土内の適宜部位に、水や湿気等により浸透する汚染物質を積極的且効率的に吸着固定或いは吸着分解消去せしめ、且客土若しくは盛土の土圧を均等に分散付加せしめるとともに土壌中の水分を透水させて圧密化を図るため、織物若しくは編物或いは不織布からなる素地全体にその平均粒径が１０乃至１００μｍの接触表面積率が極めて大きく、且大きな吸水吸着容量を保持させるために比表面積が８０ｍ２／ｇ以上及び効率良く汚染物質の吸着固定若しくは吸着分解消去を図るうえから、触媒作用に加えて強い塩基置換性を付与せしめるために塩基置換容量（ｍｅｑ／１００ｇ）が２００ｍｇ以上の人工ゼオライト粉体を用い、且その絶対吸水吸着容量並びに絶対塩基置換容量を膨大容量に保持させるうえから、少なくとも５０ｇ／ｍ２以上の塗着重量割合で且その吸水吸着性が阻害されぬよう而も透水性を保持されるよう塗着させた浄化基材を敷設させて造成させる土地の浄化造成方法に存する。
【００１０】
更に敷設される浄化基材を造成土地と同化させるために、該浄化基材を形成する素地が天然繊維若しくはポリ乳酸合成繊維からなる生分解性繊維で形成させた構成、及び造成土地の浄化を即時に図るうえから客土若しくは盛土で造成された造成地表面全体に亘って、水に対して１５乃至３０％重量割合で人工ゼオライト粉体が混合された浄化水を散水浸透させる土地の浄化造成方法に存する。
【００１１】
【作用】
本発明は上述の如き構成からなるため以下のような作用を有する。即ち土地を掘削のうえ客土造成し若しくは切土により盛土造成される造成底面及び造成される客土内若しくは盛土内の適宜部位に、敷設される浄化基材が織物若しくは編物或いは不織布からなる素地に、その平均粒径が１０乃至１００μｍの接触表面積率が極めて大きな微粒状で且その比表面積が８０ｍ２／ｇ以上の吸水吸着容量も極めて大きく、更にその塩基置換容量（ｍｅｑ／１００ｇ）が２００ｍｇ以上の強い塩基置換性を保持する人工ゼオライト粉体が、その吸水吸着性を阻害させることなく且少なくとも５０ｇ／ｍ２以上の塗着重量割合で絶対吸水吸着容量並びに絶対塩基置換容量が膨大容量に而も透水性を保持するよう塗着されてなるため、造成底面の地盤が含水軟弱な場合でも客土や盛土の土圧が均等に付加されるとともに、水分が浄化基材を透水して圧密化され略均等な土圧で造成がなされ、且含水軟弱な部分への過度の客土や盛土の埋入沈下も防止される。
【００１２】
そして造成底面や客土内若しくは盛土内の適宜部位に浄化基材が敷設されることにより、造成に係る地中からの透過水や、或いは雨水や湿気等により汚染物質が該浄化基材を透過される場合には、その接触表面積率が大きく且絶対吸水吸着容量の膨大な人工ゼオライト粉体に積極的且効率的に吸水吸着されるとともに、該人工ゼオライト粉体の触媒作用と強い塩基置換性とにより重金属類が吸着固定がなされ且有機化合物等は吸着分解消去がなされて浄化されるとともに造成後の不等沈下も防止される。加えて浄化基材を形成する素地を生分解性繊維で形成させることにより、造成後の経過とともに該素地が腐食崩壊し造成土地と同化するとともに、人工ゼオライト粉体の汚染物質に対する吸着固定若しくは吸着分解消去が長期に亘って発揮され続けられる。而も造成後に更に水に対して１５乃至３０％重量割合で人工ゼオライト粉体を混合して浄化水となしたるうえ散水せしむることにより、客土や盛土内の汚染物質が即時に吸着固定若しくは吸着分解消去されて浄化され、且造成地が締固められる。
【００１３】
【実施例】
以下に本発明実施例を図とともに詳細に説明すれば、図１は土地造成の説明図、図２は平織物からなる素地の説明図、図３は人工ゼオライト粉体の拡大説明図、図４は浄化基材の説明図であって、本発明は土地１の掘削による客土造成若しくは切土による盛土造成に際して、土地１の汚染はもとより客土１Ａや盛土１Ｂ自体が汚染されてなる場合にも浄化された造成がなされるものであって、造成される土地１はその利用状態や立地環境により、生産される製品に使用されてなる重金属類や化学薬品或いは有機化合物等の放散浸透等による汚染や、客土１Ａや盛土１Ｂにおいても煤煙や自動車排気ガス等に混在する汚染物質を初め農薬或いは化学洗剤の飛散浸透により汚染が著しく増大化されている。
【００１４】
そこで本発明は、造成される造成底面や客土１Ａ内若しくは盛土１Ｂ中の適宜部位に浄化基材２を敷設せしめて、雨水や湿気等により浸透拡散される汚染物質、若しくは地中からの浸透拡散される汚染物質を該浄化基材２で吸着固定若しくは吸着分解消去せしむる技術思想を採用するものであって、この浄化基材２は客土造成若しくは盛土造成に伴う客土１Ａや盛土１Ｂの土圧に耐えうる強靭性を初め敷設展張が容易になしえるように幅広で且柔軟性を有し、而も敷設使用に際して汚染物質を浸透拡散させる雨水や湿気水分或いは地下からの浸透水が接触透水されるように透水性を保持せしめるうえから、該浄化基材２を形成するための素地２Ａとしては図２に示すように織物若しくは編物或いは不織布が用いられる。
【００１５】
かかる場合における素地２Ａの破断強力としては、具体的に敷設される場合の客土１Ａや盛土１Ｂの土量及び土圧によっても異なるが、一般的な宅地造成の如くせいぜい３乃至５ｍ程度の客土造成若しくは盛土造成の場合では略１２０乃至１５０ｋｇ／５ｃｍ以上であれば使用に供しえる。
そして該素地２Ａに用いる織物の具体的なものとしては平織物や綾織物が安価に提供しえることから望ましく、且その全体に亘って人工ゼオライト粉体２Ｂを塗着させた場合にも透水性が保持される必要上から、その目合２０Ａとしては少なくとも０．５乃至２ｍｍ程度のものが望ましい。加えて編物の具体的なものとしてはラッセル編成若しくはメラニーズ編成による編物が挙げられる。更に該素地２Ａは人工ゼオライト粉体２Ｂを塗着させるうえから、被着性に優れる素材が使用されることは当然である。
【００１６】
而してかかる素地２Ａに塗着される人工ゼオライト粉体２Ｂは図３に示すように、造成される土地１を汚染している重金属類や化学薬品、有機化合物等の汚染物質や客土１Ａ若しくは盛土１Ｂ内の汚染物質等が、雨水や湿気水分等により浸透拡散される場合若しくは地下からの汚染物質を含む浸透水を、該浄化基材２に接触透水させることにより積極的且効率的に吸水吸着させるとともに重金属類の吸着固定或いは化学薬品や有機化合物等の吸着分解消去をなすためには接触透水時に汚染物質に対し極めて大きな接触表面積率を以って接触させる必要上から、その平均粒径が１０乃至１００μｍの微粒状で且十分に大きな吸水吸着容量を保持させるために、膨大数の微細孔隙２０Ｂを有し且その比表面積において少なくとも８０ｍ２／ｇ以上望ましくは１２０乃至１６０ｍ２／ｇのものが選択されるものであり、更に重要なことは吸水吸着させた汚染物質を吸着固定させて拡散を防止し若しくは吸着分解消去させて浄化を図ることで、これがためには本来的に保持する触媒作用に加えて強い塩基置換性所謂大きな塩基置換容量（ｍｅｑ／１００ｇ）が要請されることから、少なくともその塩基置換容量（ｍｅｑ／１００ｇ）が２００ｍｇ以上好ましくは２６０乃至３００ｍｇの人工ゼオライト粉体２Ｂが選択される。
【００１７】
そしてこの選択使用される人工ゼオライト粉体２Ｂは図４に示すように、その吸水吸着性が損われることなく、且造成に係る客土１Ａや盛土１Ｂ内の汚染物質全体量を吸着固定若しくは吸着分解消失しえる絶対吸水吸着容量並びに絶対塩基置換容量を保持せしむるうえから、素地２Ａに対して少なくとも５０ｇ／ｍ２以上の塗着重量割合を以って、而も透水性を保持させるための透水孔２０Ｃが全面に亘って形成されるように塗着されて浄化基材２が形成されている。
【００１８】
かかる場合において、塗着される人工ゼオライト粉体２Ｂの吸水吸着に係る微細孔隙２０Ｂを閉塞させぬように塗着させる方法は多くの方法が提案されるが、当然に浄化基材２の敷設使用において新たな汚染物質が溶出若しくは滲出されぬ安全なものが不可欠で且素地２Ａの柔軟性を損うことなく強固に塗着されることが要請されるため、具体的な塗着方法としては天然ゴムラテックス若しくは合成ゴムラテックスに人工ゼオライト粉体２Ｂ、及び気泡剤としてオレイン酸カリウム若しくはステアリン酸アンモニウム等を配合させて水溶性塗着材２Ｃとなしたるうえ、素地２Ａに所要の重量割合で塗着のうえ加熱乾燥を施すことにより、気泡剤による連続気泡構造２Ｄで且水分の蒸散に伴う多数の蒸散孔２Ｅを形成させることが挙げられる。
【００１９】
更に人工ゼオライト粉体２Ｂの絶対塩基置換容量に係る人工ゼオライト粉体２Ｂの塗着重量割合は、造成に用いる客土１Ａ若しくは盛土１Ｂ或いは土地１自体の汚染度合によっても異なるが、本発明における浄化基材２の汚染物質に対する浄化即ち重金属類に対する吸着固定若しくは化学薬品や有機化合物等の吸着分解消去は専らその絶対塩基置換容量に依拠する。
因みに土壌の汚染度合は、その土壌の利用履歴や立地環境によっても大きく異なるものであるが、一般的な汚染度合としては重金属類においては土壌１ｋｇ当り略０．００３乃至０．３ｍｇ程度、更に全シアン、六価クロム、砒素等の化学薬剤や有機化合物等では略０．３乃至１．５ｍｇ以下程度とされている。
而して本発明に用いる人工ゼオライト粉体２Ｂの塩基置換容量（ｍｅｑ／１００ｇ）所謂人工ゼオライト粉体１００ｇ当りの塩基置換容量は少なくとも２００ｍｇ望ましくは２６０乃至３００ｍｇのものが使用されるものであり、且素地２Ａに対して少なくとも５０ｇ／ｍ２以上の重量割合で塗着される構成である。
【００２０】
してみると仮りに塩基置換容量（ｍｅｑ／１００ｇ）が３００ｍｇの人工ゼオライト粉体２Ｂが１００ｇ／ｍ２で塗着された浄化基材２の１ｍ２当りの総塩基置換容量は３００ｍｇであるから、汚染土壌中の重金属類の吸着固定能力としては３００ｍｇ／０．００３ｍｇ乃至３００ｍｇ／０．３ｍｇ×１０００ｋｇ＝１乃至１００ｔｏｎの汚染土壌の浄化に対処できることとなり、重金属以外の化学薬剤や有機化合物においては３００ｍｇ／０．３ｍｇ乃至３００ｍｇ／１．５ｍｇ×１０００ｋｇ＝０．２乃至１．０ｔｏｎの汚染土壌の浄化に対処できることとなる。
当然に客土１Ａ若しくは盛土１Ｂ或いは土地１の汚染度合が更に高濃度に汚染されてなる場合には、浄化基材２への人工ゼオライト粉体２Ｂの塗着量を増大させる手段及び浄化基材２を造成される客土１Ａ内や盛土１Ｂ内の適宜部位に多層に亘って敷設させる手段とで対処ができる。
【００２１】
かくしてなる浄化基材２は土地１を予め所要の広さ及び深さに掘削し客土造成し若しくは切土により所要の広さと高さに盛土造成をなす場合に、造成底面３Ａ及び客土１Ａ内或いは盛土１Ｂ内の適宜部位３Ｂに敷設し造成がなされるもので、図５には客土造成３による造成態様が示されてなる如く、客土造成３による場合には先づ造成すべき土地１を所要の広さと深さを以って掘削したうえ、その造成底面３Ａの全面に亘って基材２を敷設する。
かかる場合に、浄化基材２はその形成素地１Ａが通常略９２ｃｍ、１８０ｃｍ若しくは２１０ｃｍ程度の幅で織成若しくは編成されるため、該浄化基材２の幅も同様のものとなる。
【００２２】
反面造成される造成面積は広面積となる場合が多く、従ってこの広面積の造成底面３Ａ全面に亘って浄化基材２を敷設させる場合には、浄化基材２の側縁を相互に重ね合せながら敷設させる方法もあるが、特に造成底面３Ａの地盤が含水軟弱な地盤の場合では、客土１Ａの投入による土圧の付加により軟弱部分に客土１Ａが埋入沈下し、多量の客土１Ａの使用とともに造成後においても不等沈下が招来される危険を内在する。
これがための対処としては、予め適宜数の浄化基材２の側縁相互を縫合連接して適宜広幅の一体的シート状となしたうえ敷設させることが望まれる。更にこの浄化基材２は所要の長さに巻回させたロール状に形成させておき、敷設に際してはこのロール状に巻回された浄化基材２を解巻させるのみで敷設が簡便になしえることとなる。
【００２３】
造成底面３Ａの全面に亘って浄化基材２が敷設されたる後は、所要量の客土１Ａを投入しブルドーザーやバックホー等の整地用機械を以って所要の深さ部位にまで一旦整地し、更にこの整地底面に浄化基材２を全面に亘って敷設をなし、而してその上面に再び所要量の客土１Ａを投入して整地をなすことにより本発明の浄化造成がなしえる。かかる場合に都市部の如き該土地造成に隣接する土地が他の利用に供されている場合には、造成に用いる客土１Ａの汚染物質が隣接土地に拡散せぬような配慮も要請されるため、浄化基材２の敷設端縁２Ｆを掘削壁面にまで敷設させることが望ましい。
【００２４】
本発明においては浄化基材２が造成底面３Ａや客土１Ａ或いは盛土１Ｂの適宜部位３Ｂに敷設されるものであるが、造成された土地の利用は多岐に亘るものであるから、該浄化基材２が恒久的に存在すると土地の再利用に際してその除去の問題も考慮しておく必要がある。
かかる問題に対しては、浄化基材２の形成のための素地２Ａを綿や麻等の天然繊維若しくはポリ乳酸合成繊維等の生分解性繊維で形成することにより解決できるもので、該生分解性繊維を用いた素地２Ａにより形成された浄化基材２を敷設させることにより、使用経過とともに素地２Ａが腐食崩壊して客土１Ａ若しくは盛土１Ｂと同化し、且人工ゼオライト粉体２Ｂの吸着固定や吸着分解消去機能は長期に亘って維持されることとなる。
【００２５】
而して本発明においては、造成に際しての客土１Ａや盛土１Ｂの汚染度合が大きく或いは造成する土地１が極度に汚染されている場合においても、汚染物質が雨水や湿気水分等により浸透拡散し、若しくは地下からの浸透水の浸透に際して浄化基材２により吸着固定や吸着分解消去せしめて浄化を図るものであるから、造成後の時間経過とともに造成地の浄化が促進されてゆくこととなる。
他方造成後における即時の浄化が必要な場合には、かかる手段においてのみでは不十分となる。そこで本発明においては図６に示すように、造成すべき土地１に所要の広さ及び深さで掘削がなされたうえ浄化基材２が敷設され且客土１Ａが投入されて整地され、更に該整地地面に浄化基材２が敷設されたうえ客土１Ａが投入されて整地されて造成された造成地表面全体に亘って、水に対して１５乃至３０％重量割合で人工ゼオライト粉体２Ｂを混合させた浄化水４を形成させたうえ、この浄化水４を所要量で散水浸透せしむることにより人工ゼオライト粉体２Ｂを客土１Ａ内や盛土１Ｂ内の汚染物質に積極的に浸透接触せしめて、汚染物質を吸着固定若しくは吸着分解消去せしむることが提案される。
【００２６】
かかる場合において、浄化水４の組成が水に対して人工ゼオライト粉体２Ｂが１５乃至３０％重量割合とされる所以は、１５％重量割合以下では多量の水の散水と且吸着固定や吸着分解消去の効果が遅速となることによるものであり、３０％重量割合を超えると粘性の増加により客土１Ａ内や盛土１Ｂ内への浸透性が悪くなる理由による。
そして留意すべきは、浄化水４の状態においては人工ゼオライト粉体２Ｂ内には多量の水が吸水されてなるものの、人工ゼオライト粉体２Ｂの特有の性能でもある調湿機能により、散水とともに該吸水された水が積極的に放水されたるうえ汚染物質の吸着固定や吸着分解消去がなされるものであるから過剰な散水は不要で、散水量の目途としては客土１Ａや盛土１Ｂの１ｍ３当りせいぜい２０乃至３０％重量程度に留めることが望まれる。
【００２７】
【発明の効果】
本発明は以上述べたように客土造成若しくは盛土造成に際し、その造成底面或いは客土や盛土内の適宜部位に織物や編物若しくは不織布からなる素地の全体に、その平均粒径が１０乃至１００μｍで比表面積が８０計／ｍ２以上及び塩基置換容量（ｍｅｑ／１００ｇ）が２００ｍｇ以上の人工ゼオライト粉体が、その吸水吸着性を阻害させることなく且少なくとも５０ｇ／ｍ２以上の塗着重量割合で、而も透水性が保持されるよう塗着されてなる浄化基材が敷設されるため、客土や盛土が汚染され若しくは造成する土地が汚染されてなる場合にも、雨水や湿気水分若しくは地下からの浸透水とともに汚染物質が該浄化基材を透過する場合に、その接触表面積率が極めて大きく且絶対吸水吸着容量並びに絶対塩基置換容量の膨大な人工ゼオライト粉体に積極的且効率的に重金属類の吸着固定や化学薬品、有機化合物等が吸着分解消去されて浄化がなされる。
【００２８】
加えて造成する土地の地盤が含水軟弱な場合においても、投入される客土や盛土が浄化基材に保持されて沈下埋入が防止されるとともに、造成に伴う土圧によって含水分が透過されて均等な圧密化が図られ造成されるため、造成後における不等沈下も防止される。
そして本発明は造成に際しても特別な機械を要することなく、巻回された浄化基材を解巻させるのみで展開敷設が可能なため造成工事が能率的になしえ、更に客土や盛土或いは造成する土地が極度に汚染された場合においても、造成後の造成地表面に水に対して人工ゼオライト粉体が１５乃至３０％重量割合で混合された浄化水を散水させるため、人工ゼオライト粉体が客土や盛土内に浸透し汚染物質と接触して吸着固定や吸着分解消去が積極的且効率的になされて短時に浄化が図られ而も造成地全体の締固めもなされる等、極めて多くの特長を有した土地の浄化造成方法といえる。
【図面の簡単な説明】
【図１】土地造成の説明図である。
【図２】平織物からなる素地の説明図である。
【図３】人工ゼオライト粉体の拡大説明図である。
【図４】浄化基材の説明図である。
【図５】客土造成方法の態様図である。
【図６】浄化水の散水説明図である。
【符号の説明】
１ 土地
１Ａ 客土
１Ｂ 盛土
２ 浄化基材
２Ａ 素地
２Ｂ 人工ゼオライト粉体
２Ｃ 水溶性塗材
２Ｄ 連続気泡構造
２Ｅ 蒸散孔
２Ｆ 敷設端縁
２０Ａ 目合
２０Ｂ 微細孔隙
２０Ｃ 透水孔
３ 客土造成
３Ａ 造成底面
３Ｂ 適宜部位
４ 浄化水[0001]
[Industrial applications]
The present invention can be applied to the construction of land for industrial or commercial use or residential land, even if the soil or cut soil is contaminated, or if the contaminated substances are scattered or diffused and adhered with the use of the constructed land. And a land purification method capable of purifying pollutants.
[0002]
[Prior art]
In Japan, the scale of the industry has expanded remarkably with economic growth, and as a result, a large amount of soot and other industrial wastewater and industrial waste have been continuously discharged.With the development of the chemical industry, a large amount of heavy metals, chemicals, Since organic compounds have been widely used not only for industrial purposes but also for household goods, they are extremely polluted, including soil, water and air, and in addition to the huge emission of exhaust gas accompanying the development of automobile society. Therefore, diseases caused by these are occurring frequently in various places, and environmental purification is an urgent issue both internationally and domestically.
[0003]
By the way, in soil, when pollutants such as heavy metals, chemicals, and organic compounds adhere or diffuse and penetrate, they are diffused and accumulated inside the ground, and the self-cleaning action does not work. It has the characteristic of becoming polluted.
In the past, land has been recognized for its high property value, and investment and speculation have been made not only by companies but also by individuals.However, evaluation and evaluation of contaminated land has been progressing until now. It is considered that purification of land used, as well as purification of developed land, is inevitable.
[0004]
For this reason, even in the case of embankment formation by cutting or cultivation of soil with a lot of soil, in addition to the contamination of the land to be laid, the embankment and the terrain itself are often contaminated. In addition, it is necessary to purify the embankment and the soil.
However, in urban and suburban areas, it is extremely difficult to install spaces and treatment facilities for the purification of embankment and soil, so once the mined embankment and soil have been transported to a suburban processing site for cleaning, etc. Must be re-transported to the land where it has been subjected to the purification process, which requires enormous transportation costs in addition to the purification cost. If the pollutant is used after being used, the contaminants are scattered and adhered again or diffused and permeate again as the use progresses, resulting in increased contamination.
[0005]
Therefore, as a purification method at the original site of the development site, a suction well is installed in the unsaturated zone above the groundwater level by drilling, the pressure of the contaminant is suctioned by reducing the pressure with a vacuum pump or a blower, and the contaminant vapor is removed. Including soil gas suction method of adsorbing and removing with activated carbon or oxidative decomposition with ultraviolet rays, drilling into multiple cylinders, insolubilizing special cement etc. in the soil, solidifying by injecting a solidifying agent, insolubilizing method, A heavy oil contaminated soil Washing method by flowing water into aqueous sodium silicate solution, reduction treatment method to reduce and stabilize hexavalent chromium by iron powder, or inserting an electrode in soil to disperse ionic contaminants after moving Electric separation methods and the like are known.
[0006]
However, these methods require high technology in addition to relatively large facilities, and their costs are enormous. Therefore, they cannot be put to practical use unless special budget measures are taken. No results have been heard.
Furthermore, in the land development, it is desirable to create a solid and stable ground by sufficient compaction in both embankment and land development, but on the other hand, the ground to be developed is in the wilderness, wetlands, agricultural lands, near rivers and lakes, etc. Relatively large, especially in clayey or muddy geology with lots of water, simply laying cut soil or cultivating soil with hard soil requires a very large amount of embankment or burial with hard soil, and compaction during formation is also required. There is also an inherent problem that it is insufficient and unequal settlement is caused, and repairs and repairs must be made again and again.
[0007]
As a result of repeated studies in view of such a problem, the inventor has found that, in recent years, industrial waste whose residual main component consists of silicon oxide and aluminum oxide, in particular, coal incineration ash is finely divided by alkali pretreatment and high-temperature and high-pressure treatment. The mass production of artificial zeolite powder having an enormous amount of fine pores has become possible, and the artificial zeolite powder has essentially a humidity control action and a catalytic action, and has a wide range of particle size and water absorption capacity. The specific surface area or the base substitution property relating to adsorption fixation or adsorption decomposition elimination of contaminants, so-called base substitution capacity (meq / 100 g) can be provided in a wide range, and the water absorption of the artificial zeolite powder can be improved. It is applied to a woven fabric, a knitted fabric or a non-woven fabric at a required coating weight ratio without impairing the adsorptivity so as to maintain water permeability. Investigating that it is possible to purify contaminated soil and prevent uneven settlement by laying it at the bottom of the site and at an appropriate location within the site or the embankment to be laid. Invented the invention.
[0008]
[Problems to be solved by the invention]
The present invention relates to a method for constructing a land to be excavated and then cultivated with a soil or embankment by cutting a soil, in which the soil can be purified for a long time even if the soil or the embankment is contaminated, and uneven settlement can be prevented. It is an object of the present invention to provide a possible land purification method.
[0009]
[Means for Solving the Problems]
The technical means used by the present invention to solve the above-mentioned problem is that, when the land is excavated to a required depth and is laid with the required soil, or when the embankment is laid to the required height by cutting, the land is laid. Actively and efficiently adsorbs and fixes or decomposes and removes contaminants permeated by water, moisture, etc. at the bottom of the ground and at appropriate locations within the soil or embankment, and evenly distributes the earth pressure of the soil or embankment. In order to consolidate by adding water and allowing moisture in the soil to permeate, the contact surface area ratio with an average particle diameter of 10 to 100 μm is extremely large and the large water absorption capacity is maintained over the whole woven or knitted or nonwoven fabric. In order to efficiently adsorb and fix or decompose and decompose contaminants with a specific surface area of 80 m 2 / g or more, in order to impart strong base substitution in addition to the catalytic action Using an artificial zeolite powder having a base substitution capacity (meq / 100 g) of 200 mg or more, and keeping its absolute water absorption capacity and absolute base substitution capacity at an enormous capacity, a coating weight ratio of at least 50 g / m 2 or more. In addition, the present invention relates to a method for purifying land by laying and constructing a purification substrate coated so as to maintain water permeability so that its water absorption and adsorption properties are not impaired.
[0010]
Further, in order to assimilate the purification base material to be laid with the developed land, a construction in which the base material forming the purification base material is formed of biodegradable fibers made of natural fibers or polylactic acid synthetic fibers, and purification of the developed land is carried out. Immediately pursuing and purifying the land by spraying and infiltrating purified water mixed with artificial zeolite powder at a weight ratio of 15 to 30% with respect to the water over the entire surface of the land created by the guest soil or embankment Be in the way.
[0011]
[Action]
Since the present invention has the above configuration, it has the following operations. That is, a purification base material to be laid on a laid bottom on which the excavation of the land is performed and the soil is laid or the embankment is laid by cutting, and on an appropriate site in the laid soil or the embankment, the purification base material to be laid is made of a woven fabric, a knitted fabric, or a nonwoven fabric. In addition, the fine particles having an average particle size of 10 to 100 μm and having a very large contact surface area ratio and a specific surface area of 80 m 2 / g or more have a very large water absorption capacity, and further have a base substitution capacity (meq / 100 g) of 200 mg. The artificial zeolite powder having the above-mentioned strong base-substituting property has an absolute water-absorbing adsorption capacity and an absolute base-substituting capacity of an enormous capacity without impairing the water-absorbing and adsorbing property and at a coating weight ratio of at least 50 g / m 2 or more. Since it is coated so as to maintain water permeability, even if the ground at the bottom of the formation is soft and wet, the earth pressure of the guest soil and embankment is added evenly Water reclamation substantially uniform earth pressure compacted by water permeation purification substrate is made, implantation subsidence excessive soil dressing or embankment to 且含 water fragile portion is prevented.
[0012]
The purification base material is laid at an appropriate site in the construction bottom, in the guest soil or in the embankment, so that contaminants permeate through the purification base material due to permeated water from the ground related to the development, or rainwater or moisture. In this case, the artificial zeolite powder having a large contact surface area ratio and an enormous absolute water absorption capacity is positively and efficiently adsorbed on water, and the catalytic action of the artificial zeolite powder and strong base substitution As a result, heavy metals are adsorbed and fixed, and organic compounds and the like are adsorbed, decomposed and eliminated to be purified, and uneven settlement after the formation is prevented. In addition, by forming the base material that forms the purification base material with biodegradable fibers, the base material corrodes and disintegrates with the progress of the construction, assimilate with the created land, and adsorbs and fixes or adsorbs the artificial zeolite powder on contaminants. Decomposition and elimination can be continued for a long time. Further, after the formation, artificial zeolite powder is further mixed at a weight ratio of 15 to 30% with respect to water to form purified water and sprinkle water, thereby immediately adsorbing pollutants in the soil and embankment. It is fixed or decomposed by elimination by adsorption and purified, and the developed land is compacted.
[0013]
【Example】
FIG. 1 is an explanatory view of land preparation, FIG. 2 is an explanatory view of a plain fabric, FIG. 3 is an enlarged explanatory view of an artificial zeolite powder, FIG. FIG. 2 is an explanatory view of a purification base material. In the present invention, when the soil is formed by excavation of the land 1 or the embankment is formed by cutting, the soil 1A or the embankment 1B itself is contaminated as well as the soil of the land 1. The land 1 to be created depends on its use condition and location environment, and is caused by the diffusion and infiltration of heavy metals, chemicals, organic compounds, and the like used in the products to be produced. Pollution has also been significantly increased in the soil 1A and the embankment 1B due to scattering and infiltration of pesticides or chemical detergents, including pollutants mixed in soot and automobile exhaust gas.
[0014]
Therefore, the present invention is to lay the purification base material 2 at an appropriate site in the construction bottom to be constructed, in the soil 1A or in the embankment 1B, and to contaminate or permeate and diffuse from the ground by rainwater or moisture. The present invention employs a technical idea of adsorbing and fixing or adsorbing, decomposing and erasing contaminants to be diffused by the purifying base material 2. The purifying base material 2 includes a soil 1A and an embankment for embankment. It is wide and flexible so that it can be easily laid and expanded at first, and has the toughness that can withstand the earth pressure of 1B. Also, rainwater, moisture and moisture that penetrate and diffuse contaminants when laying, or seepage water from underground In order to maintain the water permeability so as to make the contact water permeate, a woven fabric, a knitted fabric, or a nonwoven fabric is used as the base 2A for forming the purification substrate 2 as shown in FIG.
[0015]
The breaking strength of the base material 2A in such a case differs depending on the soil volume and earth pressure of the concrete soil 1A and the embankment 1B when laid concretely, but it is at most about 3 to 5 m like general residential land development. In the case of earth formation or embankment formation, it can be used if it is approximately 120 to 150 kg / 5 cm or more.
As a specific fabric used for the base 2A, a plain fabric or a twill fabric is desirable because it can be provided at a low cost, and even when the artificial zeolite powder 2B is applied over the whole, Is required, the size 20A is preferably at least about 0.5 to 2 mm. In addition, specific examples of the knitted fabric include a knitted fabric by Russell knitting or Melanie's knitting. Further, the substrate 2A is coated with the artificial zeolite powder 2B, and it is natural that a material having excellent adherence is used.
[0016]
As shown in FIG. 3, the artificial zeolite powder 2B applied to the substrate 2A is a contaminant such as heavy metals, chemicals, organic compounds, etc., and the soil 1A contaminating the land 1 to be formed. Alternatively, when contaminants and the like in the embankment 1B are permeated and diffused by rainwater, moisture, or the like, or by infiltrating permeated water containing contaminants from the underground to the purification base material 2, it is positively and efficiently. In order to absorb and adsorb water and to fix and fix heavy metals or to decompose and decompose chemicals and organic compounds, it is necessary to contact pollutants with an extremely large contact surface area ratio during contact water permeation. In order to maintain a fine and granular water absorption capacity of 10 to 100 μm, it has an enormous number of fine pores 20B and a specific surface area of at least 80 m 2 / g or more. Desirably, those having a particle size of 120 to 160 m 2 / g are selected. More importantly, the contaminants adsorbed by water are adsorbed and fixed to prevent diffusion, or by purifying by decomposing and erasing, thereby purifying. For this purpose, in addition to the inherent catalytic activity, a strong base substitution property, that is, a large base substitution capacity (meq / 100 g) is required. Therefore, at least the base substitution capacity (meq / 100 g) is preferably 200 mg or more. 260 to 300 mg of artificial zeolite powder 2B is selected.
[0017]
As shown in FIG. 4, the artificial zeolite powder 2B to be selectively used is capable of adsorbing or fixing the total amount of pollutants in the soil 1A and the embankment 1B, without impairing its water absorption and adsorbing properties. In order to maintain the absolute water absorption capacity and the absolute base substitution capacity that can be decomposed and disappear, and to maintain water permeability with a coating weight ratio of at least 50 g / m 2 or more to the base material 2A. The purification base material 2 is formed by applying such that the water permeable holes 20C are formed over the entire surface.
[0018]
In such a case, many methods have been proposed for applying the artificial zeolite powder 2B to be applied so as not to block the micropores 20B relating to the water absorption and adsorption of the artificial zeolite powder 2B to be applied. It is indispensable to use a safe material in which new contaminants are not eluted or exuded, and it is required that the material be firmly applied without impairing the flexibility of the substrate 2A. A rubber latex or a synthetic rubber latex is mixed with artificial zeolite powder 2B and a foaming agent such as potassium oleate or ammonium stearate to form a water-soluble coating material 2C. By applying heat and drying after wearing, it is possible to form a large number of transpiration holes 2E with an open cell structure 2D formed by a foaming agent and the evaporation of water.
[0019]
Furthermore, the coating weight ratio of the artificial zeolite powder 2B related to the absolute base substitution capacity of the artificial zeolite powder 2B differs depending on the degree of contamination of the soil 1A or the embankment 1B or the land 1 itself used for the formation. Purification of the base material 2 for contaminants, that is, adsorption and fixation of heavy metals or adsorption decomposition elimination of chemicals and organic compounds, etc., exclusively depends on the absolute base substitution capacity.
Incidentally, the degree of soil contamination varies greatly depending on the usage history of the soil and the location environment. As a general level of contamination, about 0.003 to 0.3 mg / kg of heavy metals and about For chemical agents such as cyanide, hexavalent chromium, and arsenic, and organic compounds, the amount is about 0.3 to 1.5 mg or less.
The base substitution capacity (meq / 100 g) of the artificial zeolite powder 2B used in the present invention is at least 200 mg, preferably 260 to 300 mg, per 100 g of the artificial zeolite powder. It is configured to be applied at a weight ratio of at least 50 g / m 2 or more to the base 2A.
[0020]
As a result, if the artificial base zeolite powder 2B having a base substitution capacity (meq / 100 g) of 300 mg was applied at 100 g / m 2 , the total base substitution capacity per 1 m 2 of the purification substrate 2 was 300 mg. The ability to fix and fix heavy metals in contaminated soil is 300 mg / 0.003 mg to 300 mg / 0.3 mg x 1000 kg = 1 to 100 tons. 300 mg / 0.3 mg to 300 mg / 1.5 mg × 1000 kg = 0.2 to 1.0 ton.
When the soil 1A or the embankment 1B or the land 1 is naturally contaminated at a higher concentration, the means for increasing the amount of the artificial zeolite powder 2B applied to the purification substrate 2 and the purification substrate 2 can be dealt with by means of laying in multiple layers at appropriate locations in the built soil 1A or the embankment 1B.
[0021]
The thus-purified base material 2 is used for excavating the land 1 to a required size and depth in advance and cultivating the soil to the required extent and height by cutting the lands, thereby forming the ground 3A and the terrain 1A. It is laid at an appropriate portion 3B in the inside or the embankment 1B and is formed. As shown in FIG. The land 1 is excavated with a required area and depth, and a base material 2 is laid over the entire bottom surface 3A.
In such a case, since the purification base material 2A is usually woven or knitted with a width of about 92 cm, 180 cm, or 210 cm, the width of the purification base material 2 is the same.
[0022]
On the other hand, the formation area to be formed is often a large area. Therefore, when the purification base material 2 is laid over the entire formation bottom surface 3A having the large area, the side edges of the purification base material 2 are overlapped with each other. There is also a method of laying, but especially in the case where the ground of the formation bottom 3A is soft and wet, the soil 1A is buried and settled in the soft part due to the addition of earth pressure due to the input of the soil 1A, and a large amount of soil With the use of 1A, there is a danger that uneven settlement will be caused even after the construction.
As a countermeasure for this, it is desired that the side edges of an appropriate number of the cleaning base materials 2 are sewn and connected in advance to form an integrated sheet having a wide width and then laid. Further, the purifying base material 2 is formed in a roll shape wound to a required length, and when laying, the purifying base material 2 wound in a roll shape is simply unwound, so that the laying can be easily performed. It will be.
[0023]
After the purification base material 2 is laid over the entire surface of the formation bottom surface 3A, a required amount of the soil 1A is put in, and the ground is temporarily ground to a required depth by using a bulldozer or a backhoe or the like. Further, the purification base material 2 is laid on the entire bottom surface of the ground, and the required amount of the soil 1A is again put on the upper surface thereof to perform the ground preparation. In such a case, if the land adjacent to the land development, such as an urban area, is being used for other purposes, consideration must be given to prevent the contaminants of the soil 1A used for the development from spreading to the adjacent land. Therefore, it is desirable to lay the laying edge 2F of the purification base material 2 to the excavation wall surface.
[0024]
In the present invention, the purification substrate 2 is laid on an appropriate portion 3B of the construction bottom surface 3A, the soil 1A, or the embankment 1B. However, since the use of the constructed land is diversified, the purification substrate 2 is used. If the material 2 is permanently present, it is necessary to consider the problem of its removal when reusing the land.
Such a problem can be solved by forming the base 2A for forming the purification substrate 2 with natural fibers such as cotton and hemp or biodegradable fibers such as polylactic acid synthetic fiber. By laying the purification base material 2 formed of the base material 2A using the conductive fiber, the base material 2A corrodes and collapses with use and assimilates with the soil 1A or the embankment 1B, and adsorbs and fixes the artificial zeolite powder 2B. And the adsorption / decomposition / elimination function is maintained for a long period of time.
[0025]
Thus, in the present invention, even when the soil 1A or the embankment 1B at the time of the formation is highly contaminated or the land 1 to be formed is extremely contaminated, the contaminants penetrate and diffuse due to rainwater, moisture, and the like. Alternatively, when the permeated water penetrates from underground, the purification is performed by adsorbing and fixing or adsorbing and decomposing by the purifying base material 2, so that the purification of the development site is promoted as time elapses after the development.
On the other hand, when immediate purification after the construction is required, such means alone is not sufficient. Therefore, in the present invention, as shown in FIG. 6, excavation is performed on the land 1 to be created to a required area and depth, a purification base material 2 is laid, and the soil 1A is put into the land 1, and the land is leveled. A purification base material 2 is laid on the leveling ground, and the artificial zeolite powder 2B is added at a weight ratio of 15 to 30% with respect to water over the entire surface of the land where the cleaning soil 2A is charged and leveled. Is formed and purified water 4 is sprinkled and infiltrated in a required amount to artificially infiltrate artificial zeolite powder 2B into contaminants in guest soil 1A and embankment 1B. It is proposed that the contaminants be adsorbed and fixed or adsorbed, decomposed and eliminated by contact.
[0026]
In such a case, the reason why the composition of the purified water 4 is such that the artificial zeolite powder 2B is 15 to 30% by weight with respect to water is that, when the composition is less than 15% by weight, a large amount of water is sprayed and the water is adsorbed and fixed or adsorbed and decomposed. This is because the effect of the erasing is slowed down, and when the weight ratio exceeds 30%, the permeability increases into the soil 1A or the embankment 1B due to an increase in viscosity.
It should be noted that in the state of the purified water 4, although a large amount of water is absorbed into the artificial zeolite powder 2B, the artificial zeolite powder 2B has a humidity control function that is also a characteristic of the artificial zeolite powder 2B. Since the absorbed water is positively discharged, and the adsorption and fixation of the pollutants and the adsorption and decomposition are performed, excessive watering is not necessary. The target amount of watering is 1 m 3 of the soil 1A or the embankment 1B. It is desirable to keep the weight to about 20 to 30% at most.
[0027]
【The invention's effect】
As described above, in the present invention, when forming the soil or embankment, the average particle size of the woven fabric, knitted fabric, or nonwoven fabric on the bottom surface of the soil or an appropriate portion in the soil or the embankment is 10 to 100 μm. An artificial zeolite powder having a specific surface area of 80 g / m 2 or more and a base substitution capacity (meq / 100 g) of 200 mg or more has a coating weight ratio of at least 50 g / m 2 or more without impairing its water absorption and adsorption properties. However, since the purification base material coated to maintain the water permeability is laid, even when the soil to be buried or the embankment is contaminated or the land to be constructed is contaminated, rainwater, moisture and moisture, When the contaminant permeates the purification substrate together with the permeated water from the artificial zeolite, the contact surface area ratio is extremely large and the absolute water absorption capacity and the absolute base substitution capacity are enormous. The powder is positively and efficiently adsorbed and fixed to heavy metals, and the chemicals, organic compounds and the like are adsorbed, decomposed and eliminated, thereby purifying the powder.
[0028]
In addition, even when the ground of the land to be developed is soft and wet, the injected soil and embankment are retained by the purification base material, preventing settlement and embedding, and moisture content is transmitted by the earth pressure accompanying the creation. Since uniform compaction is achieved by the formation, uneven settlement after the formation is also prevented.
The present invention does not require a special machine even when constructing, and can be deployed and laid simply by unwinding the wound purification substrate. Even if the land is extremely contaminated, the artificial zeolite powder is sprayed on the surface of the created land after the artificial zeolite powder is sprinkled with 15 to 30% by weight of purified water mixed with water. Extremely many, such as penetrating into the soil and embankment and coming into contact with pollutants to actively and efficiently adsorb and fix or decompose and decompose, purify in a short time, and compact the entire land. It can be said that this is a land purification method with the following features.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of land development.
FIG. 2 is an explanatory diagram of a base made of a plain woven fabric.
FIG. 3 is an enlarged explanatory view of an artificial zeolite powder.
FIG. 4 is an explanatory view of a purification substrate.
FIG. 5 is a diagram showing an embodiment of a method for creating a soil.
FIG. 6 is an explanatory diagram of spraying purified water.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Land 1A Customer soil 1B Embankment 2 Purification base material 2A Base material 2B Artificial zeolite powder 2C Water-soluble coating material 2D Open-cell structure 2E Evaporation hole 2F Laying edge 20A Mesh 20B Micropore 20C Water penetration hole 3 Customer soil creation 3A Creation bottom 3B Appropriate site 4 Purified water
