The water level of ®ve river stages and seven groundwater wells in the Taipei Basin were analysed by spectral analysis in the frequency domain. The diurnal, semi-diurnal and quarter-diurnal tidal components of the Tanshui River appear to relate closely to astronomical tides as K 1 , M 2 and M 4 , respectively. It is also found that the diurnal component reveals a reversed phase angle in the middle section of the Tanshui River; the phase of the quarter-diurnal component is also found to be reversed at stations upstream in the Tanshui River and Hsintien Stream. It is believed that these phenomena could be caused by local variation in the river channel topography. The autospectrum and cross-spectrum between groundwater elevation and nearby river stage were observed to correlate highly with the frequency of the astronomical tides K 1 , M 2 and M 4 . From the study of the phase shift and time lag of water level¯uctuations at river stages and groundwater wells, it was found that the tidal eects of diurnal, semi-diurnal, and quarter-diurnal components were signi®cantly dierent. The relationships between phase and the¯uctuated range of atmospheric pressure and water level imply that change in atmospheric pressure does not aect water level¯uctuation in the river stage and groundwater well.

The purpose of this research was a large-scale project, of an on-farm remediation of cadmium-contaminated silty loam by an electrokinetic treatment process in Taiwan. The electrokinetic (EK) treatment process is a useful remedial technology, particularly for soil with low permeability. This pilot test farm implements EK technology to remove heavy metal Cd from the silty loam in rice paddies, and evaluates the removal efficiency of the Cd, as well as soil fertility enhancement during the EK treatment process. A citric acid-surfactant mixture was used as the treatment solution, applied under an electrical current, to improve the removal of the Cd, while simultaneously enhancing the fertility of the silty farm soil. The test results revealed that the EK process gained a Cd removal efficiency of 76.6%; in addition, the contents of organic matter, total nitrogen, Bray-1 phosphorus, and exchangeable potassium and magnesium were relatively elevated after 92 days of treatment duration. This study concluded that the on-farm EK treatment technology would be capable of mitigating soil contaminated with not only heavy metals, but also organic compounds in the future. Copyright # 2008 John Wiley & Sons, Ltd. ferme a été capable d'améliorer des terres contaminées, non seulement en les débarrassant des métaux lourds mais également en améliorant leur structure organique à long terme.

The aim of this study is to develop methodologies suitable for conducting multiple organic solvent exposure assessments for workers in the plastic material printing industries. By reviewing the existing sampling and analytical methods for the seven organic solvents used in the industry (including isopropyl alcohol, 2-butanone, ethyl acetate, methyl isobutyl ketone, toluene, n-butyl acetate, and cyclohexanone), coconut shell charcoal is suggested as an appropriate sorbent media for collecting samples, and GC/FID is chosen as the instrument for chemical analyses. Both CS 2 + 5% (v/v) 1-butanol and CS 2 + 5% (v/v) isobutanol are proposed as candidate desorption reagents. Since the recovery rates obtained from the latter (83.47%-99.84%) are higher than those of the former (80.12%-98.00%), the latter is chosen in the present study. The linearities of all the resulting calibration curves are r 2 ≥ 0.995, with recovery rates (R) of ≥ 75%, and the corresponding coefficients of variations (CV) ≤ 7% for all target organic solvents. The results also suggest that the collected samples should be stored in a -10°C environment and be analyzed within 30 days. Finally, suggestions are made for amending the storage temperatures and storage days currently promulgated in related NIOSH methods based on data obtained from present study. The proposed methodology would be beneficial to the plastic material printing industry, enabling the simultaneous assessment of workers' exposure to multiple organic solvents.