Osami Nakasugi

Bisphenol A in hazardous waste landfill leachates

The levels of bisphenol A in hazardous waste landfill leachates collected in Japan in 1996 were determined by gas chromatograph/mass spectrometer (GC/MS). Bisphenol A was found in seven of 10 sites investigated. All the hazardous waste landfills with leachates contaminated by bisphenol A were controlled. The concentrations of bisphenol A ranged from 1.3 to 17,200 microg/l with a median concentration of 269 microg/l. The source of bisphenol A in landfill leachates may be the waste plastics in waste landfill. The concentrations of bisphenol A in some samples exceeded the EC50 or LC50 levels for aquatic biota. Landfill leachates may be a significant source of bisphenol A found in the environment.

Determination of the abundance of δ15N in nitrate ion in contaminated groundwater samples using an elemental analyzer coupled to a mass spectrometer

A rapid method for measuring the delta15N of nitrate ion in water samples using an isotope ratio mass spectrometer coupled to an elemental analyzer system (EA-MS) was investigated. The water should be removed from the analytical sample before measurement with this system. We investigated the application of a super-absorbent polymer resin powder to various water samples. Each 1 mg of polymer resin powder can absorb about 50-100 mg of solution depending on the concentrations of major ions. Only samples which contain more than 100 mg l(-1) of nitrate-nitrogen are suitable to be absorbed by the polymer resin for the determination of delta15N of nitrate. Preconcentration by rotary evaporation was necessary for dilute samples but the temperature should be kept below 60 degrees C. The polymer resin (about 8 mg) containing the nitrate was directly analyzed using an EA-MS after being oven-dried at 80 degrees C. Good accuracy (precision +/- 0.3%) for delta15N measurements of nitrate-nitrogen in a sample without any isotope fractionation effects during pre-treatment was observed. Results for delta15N of nitrate in contaminated groundwater samples collected in the spring at a tea plantation area in Shizuoka, Japan, were from 9.8 to 10.6%, which were close to the delta15N abundance in organic fertilizers.

Diffusive exchange of linear alkylbenzenesulfonates (LAS) between overlying water and bottom sediment

Linear alkylbenzenesulfonate (LAS) was detected in a 0–30 cm deep sediment column collected in Lake Teganuma (one of the most polluted lakes in Japan). The range of the LAS concentration in sediments was between 0.1 and 500 µg g−1 (C11–C14 homologs per dry solid) and its vertical profile showed a seasonal variation. A mathematical model, which includes a diffusion term and a biodegradation term, was used to simulate the temporal variation of LAS in the sediment column and to calculate the diffusive flux rate of LAS across the sediment/water interface. An averaged diffusion coefficient of 2.4 × 10−5 cm2 s−1 for the sediment interstitial water was obtained from sediment core samples located in Lake Teganuma. The biodegradation rate constant (0.002 d−1) of LAS in the sediment obtained from the model analysis was considerably less than that reported for LAS in anaerobic waters. These results confirm that a model describing diffusive transport and biodegradation of LAS in the sediments can simulate the temporal variation of LAS in near surface sediments. The diffusive flux rate from overlying water to bottom sediment was calculated to be between −0.20 and 0.52 (C11–C14 LAS) mg m−2 h−1 and the annual net flux rate was 0.7 g m−2 y−1.

Behavior of soil nitrogen and leaching of metal elements from arable land

In Japan, large amounts of fertilizer nitrogen are applied to tea plantations. We collected samples of tea plantation soil each season for a year. Samples were analyzed for their contents of various inorganic chemicals and total N. Nitrogen was present mainly in the top 0 to 30 cm of soil. However, at times the concentration of nitrate N in the soil water was more than 35 mg L−1, even in the deepest layers. The contents of various metal elements in the soil were examined. Ba, Fe, Sr and Zn contents were high in the top 0 to 30 cm of soil. But Al and Mn contents were not always high in the top 0 to 30 cm of soil. From the correlation analysis among contents of various inorganic chemicals, it was suggested that increased leaching of Al, Mn, and Zn from tea plantation soil occurred with increased nitrate N concentration.

Special Issues: Trend of Hazardous Waste Management in Japan. Revision of Wastes Disposal Standards in Japan.

18年ぶりに行われた水質環境基準の改訂や海洋投入処分の原則禁止を求めたロンドン条約の改正を受けて, 廃棄物最終処分基準の見直しが行われた。水質環境基準の見直しでは15項目が新たに追加され, 2項目の基準値が改められたが, 埋立処分や海洋投入処分に係わる廃棄物の判定基準も, 既に定められていたトリクロロエチレンとテトラクロロエチレンを除く13項目が新たに追加されるとともに, 鉛とヒ素の2項目の基準値が改められた。一方, ロンドン条約の付属書の見直しに伴い, 海洋投入処分基準に別の4項目が追加された。また, シュレッダーダストの管理型処分地への埋立方法の変更が検討されている。さらに, ロンドン条約における海洋投入処分を原則禁止する動きに対応して, 海洋投入処分基準の強化が検討されており, 有害物質汚染によるリスク管理に対する関心の高まりを受けて, 廃棄物最終処分基準は今後, さらに見直されていくものと考えられる。

Perspective on Hazardous Waste Management.

廃棄物問題は量的にも埋立処分地の逼迫など困難な問題を抱えているが, 質的にも, (1) 管理が必要な有害化学物質が増加する, (2) 廃棄物処理によるクロスメディア汚染の影響に対処する必要がある, (3) 跡地開発に伴い多量の汚染土壌が排出される, (4) 処理困難な廃棄物が増加するのに対し, 処理体制の整備が追いつかず, 不適切な処理が増大する, (5) 国際的な規制に対する調和が求められることなどによって, 有害廃棄物の管理がますます困難なものとなると予想される。有害廃棄物を適切に管理していくには, 4つの対策を順番に実施していく必要がある。 (1) 製造段階で有害化学物質の使用量をできるだけ削減すること。 (2) 廃棄物中の有害化学物質をできるだけ回収すること。 (3) それでも排出される有害廃棄物は適切な方法で処理して無害化すること。 (4) 無害化できない有害廃棄物は永久に保管すること。

An Economical Evaluation on Urban Waste Resource Recovery Systems

Abstract A preliminary analysis is given of the economics of resource recovery systems utilizing the post-consumer municipal refuse. Several systems have been identified for three types of resource recovery, namely, materials recovery (MR), energy recovery (ER) and land reclamation (LR). A general expression for the economics about a resource recovery system has been formulated, and major sources of revenue are discussed in detail with particular emphasis on the revenue from the dump fee. Possibilities of internalization of various economic externalities by the resource recovery have been searched for and a modification of the dumping revenue expression has been proposed to include the externalities.

A Pilot Study of Regional Water Quality Management

Abstract A comprehensive practical procedure for regional water quality management is proposed based on environmental soundness, economic optimality, and equity. This procedure is then applied to a study area.