キク科の植物を用いた汚染土壌中の石油系炭化水素の分解

Petroleum hydrocarbons degradation in contaminated soil using the plants of the Aster family.

• Ricksy Prematuri
• Noor F Mardatin
• Ratna Irdiastuti
• Maman Turjaman
• Tadao Wagatsuma
• Keitaro Tawaraya

抄録

石油採掘は、総石油炭化水素による土壌汚染の原因の一つである。本研究の目的は、キク科植物が汚染土壌中の石油系炭化水素の分解に及ぼす影響を明らかにすることであった。全石油系炭化水素(TPH)を40および90gkg含有する初期土壌を調製した。処理は3つの処理があった。(1)無添加、(2)FeClとニトリロ三酢酸(NTA)溶液の添加、(3)FeCl+NTAの添加とキク科植物9株の栽培の3つの処理を行った。TPHの濃度は、赤外分光光度計を用いて、移植後2ヶ月、3ヶ月後に測定した（MAT）。また、シュートと根の乾燥重量を3MATで測定した。Cosmos caudatusを用いて栽培した土壌のTPH濃度は、初期土壌（40gkg TPH）よりも低かった（2 MAT）。また，カレンデュラオフィシナリス，カリステフス・チネンシス，C. caudatusおよびTagetes sp.を用いて栽培した土壌のTPH濃度は，初期土壌よりも低かった（3MAT）．Achillea filipendulina, Anthemis tinctoria, Tagetes erecta, Chrysanthemum coronarium, C. officinalis, C. chinensis, C. caudatusで栽培した土壌のTPH濃度は、初期土壌（90gkg TPH）よりも低く、2 MATであった。T. erecta, A. tinctoria, Zinnia elegans, C. chinensis, C. caudatus, Tagetes sp.で栽培した土壌のTPH濃度は、初期土壌よりも低かった（3 MAT）。A. filipendulinaとC. coronariumは40kg TPHと90kg TPHの両土壌で枯死した。これらの結果は、キク科植物の根が汚染土壌中で石油系炭化水素を分解することを示唆しており、C. chinensisやZ. elegansはTPHによる浄化に適していることを示唆している。植物の生存率と広範な根系が汚染土壌中のTPHの浄化に重要な要素であることが示唆された。

Oil extraction is one of the causes of soil contamination with the total petroleum hydrocarbons. The objective of this study was to clarify the effect of Asteraceae plants on the degradation of petroleum hydrocarbon in contaminated soil. Initial soils with 40 and 90 g kg of total petroleum hydrocarbon (TPH) were prepared. There were three treatments: (1) no addition, (2) addition of FeCl and nitrilotriacetic acid (NTA) solution, and (3) addition of FeCl + NTA and the cultivation of nine Asteraceae plants. The concentration of TPH was measured using infrared spectrophotometer, 2 and 3 months after transplanting (MAT). Shoot and root dry weights were measured 3 MAT. The concentration of TPH in soil cultivated with Cosmos caudatus was lower than that of the initial soil (40 g kg TPH), 2 MAT. The concentrations of TPH in soils cultivated with Calendula officinalis, Callistephus chinensis, C. caudatus, and Tagetes sp. were also lower than that in the initial soil, 3 MAT. The concentrations of TPH in soils cultivated with Achillea filipendulina, Anthemis tinctoria, Tagetes erecta, Chrysanthemum coronarium, C. officinalis, C. chinensis, and C. caudatus were lower than that in the initial soil (90 g kg TPH), 2 MAT. The concentrations of TPH in soils cultivated with T. erecta, A. tinctoria, Zinnia elegans, C. chinensis, C. caudatus, and Tagetes sp. were lower than that in the initial soil, 3 MAT. A. filipendulina and C. coronarium died at both 40 and 90 kg TPH soils. These results suggest that the roots of Asteraceae plants degrade petroleum hydrocarbon in contaminated soil and C. chinensis and Z. elegans are more suitable for using TPH remediation. Plant survival and extensive root system are important factors for the remediation of TPH in contaminated soil.