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Mawuli Dzakpasu Miklas Scholz Rory Harrington Valerie McCarthy Siobhán Jordan 《Ground Water Monitoring & Remediation》2014,34(3):51-64
The concept of integrated constructed wetlands (ICW) promotes in‐situ soils to construct and line wetland cells. The integrity of soil material, however, may provide a potential pathway for contaminants to flow into the underlying groundwater. This study assessed the extent of groundwater quality deterioration due to the establishment of a full‐scale ICW system treating domestic wastewater in Ireland. The ICW is located at Glaslough in Co. Monaghan, Ireland. It consists of two sedimentation ponds and a sequence of five shallow vegetated wetland cells. The ICW cells were lined with 500‐mm thick local subsoil material, which comprised a mixture of alluvium, organic soils, tills, and gravel. Groundwater samples and head data were collected from eight piezometers, which were installed around the ICW cells. The groundwater and wetland water samples were analysed for water quality parameters such as bulk organic matter, nutrients, and pathogens. Overall, the quality of groundwater underlying the ICW system recorded some contamination with bulk organic matter and some inorganic nutrients. Significantly higher contaminant concentrations were recorded in monitoring wells upgradient and near to the distal wetland cells than downgradient ones, which were near to the proximal cells. For the downgradient piezometers, concentrations seldomly exceeded the natural background levels. Detailed analyses through the application of chemometrics models indicated that the source of contamination was largely of geogenic origin. Findings suggest that ICW systems pose a minimal risk to the groundwater quality; the greatest risk was associated with the distal wetland cells. 相似文献
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An Estimation of Rock Strength Using a Drilling Performance Model: A Case Study in Blacktip Field,Australia 总被引：1，自引：0，他引：1
This paper presents the results of a case study performed in Well BT-1 in the Blacktip field; an offshore field located in
northern Australia. An analytical model based on mud logging data was used to estimate a formation’s strength in Well BT-1.
The drilled well is vertical and the input data to the model included the rate of penetration, rotary speed, weight on bit
and torque values of the bit obtained from mud logging data. The final model was completed in several steps: estimation of
the bit constants from either lab or field data, backward calculation of rock strength using a drilling performance model,
smoothing of the estimated log to obtain the apparent rock strength log and classifying the formations into zones with similar
strength values. The results of a log-based approach carried out in Well BT-1 were used to do the modelling. The results presented
here indicate that the drilling performance model is able to predict the formation strength reasonably well. Based on the
results, care should be taken when the model is used for the intervals where the bit is worn and dull, since within these
intervals the model tends to over-estimate the rock strength. 相似文献
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