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排序方式: 共有1005条查询结果,搜索用时 15 毫秒
62.
Removal of sulphate and toxic elements from the leachate of a field landfill lysimeter (112m(3)), containing municipal solid waste incineration (MSWI) bottom ash, was studied. The leachate was treated in two parallel laboratory upflow anaerobic sludge blanket (UASB) reactors without and with ethanol as additional carbon source. With ethanol more than 65% of sulphate was removed, while without ethanol removal was negligible. The treatment removed Ba, Ca, Cu, Mn, Mo, Ni, Pb, Tl, Sb, Se, Sr, and Zn of the studied 35 trace and other elements. The sequential extraction of the reactor sludge at the end of runs confirmed that with a few exceptions (Ba, Ca, and Cu) the main mechanism by which the elements were removed was precipitation as sulphides. 相似文献
63.
Total adsorbable organic iodine (TAOI) has been used as a surrogate parameter for X-ray contrast media in municipal wastewater. Available methods require specialized equipment for pyrolyzing these compounds to convert the covalently bound iodine into iodide, which is then measured by ion chromatography. In this study we describe a simple method for liberating iodide from these compounds with Cu(II) and hydrogen peroxide. Concentrations of TAOI were measured in wastewater effluent, surface waters that were expected to be impacted by wastewater, and unimpacted surface waters. TAOI concentrations ranged between 1.9 and 16.3 microg/L I in wastewater with a median of 6.5 microg/L I. The lowest TAOI concentrations consistently were detected in a wastewater treatment plant that apparently had few hospitals within its collection area. In comparison, TAOI concentrations in surface water that was unimpacted by sewage were between 0.3 and 3.5 microg/L I. TAOI concentrations in surface waters that were impacted by sewage were consistent with the expected conservative behavior of TAOI. 相似文献
64.
New York City's watershed management strategy is unprecedented in its scope, scale, and cost. 相似文献
65.
The effects of freezing and thawing on the survival of Escherichia coli O157:H7 in apple juice 总被引:1,自引:0,他引:1
Unpasteurized apple juice, adjusted to pH 3.6 to 7.0 was inoculated (10(7) CFU/ml) with single strains of E. coli O157:H7 to evaluate the effect of frozen storage on the viability of this organism. Samples were stored under frozen conditions (-20+/-2 degrees C) for up to 16 days. Cell populations were determined at regular intervals by plating onto tryptic soy agar with added pyruvate (TSAP) or onto sorbitol MacConkey agar (SMA). Populations in the neutralized juice remained unchanged during frozen storage. Populations in non-neutralized juice decreased by 1-3 log10 CFU/ml depending on the strain tested and the pH of the juice. The greatest population decrease was observed with the first freeze/thaw cycle of frozen storage (24 h) and a slow decline in survival occurred thereafter. Injury was observed after 2 weeks of storage when juice pH was at or below pH 4.2. When samples were subjected to multiple freeze/thaw cycles, loss of viability and injury increased with each freeze/thaw cycle. 相似文献
66.
陈晓琳 《探矿工程(岩土钻掘工程)》2014,(11)
<正>本刊讯2014年11月21日,中国地质科学院勘探技术研究所在河南安棚天然碱矿实施的一对水平对接井在水平井井深3240 m处实现了一次对接连通。这是勘探所继在湖北沙隆达盐矿连通2800 m深井以来的又一新突破,创水平对接井井深新记录。并且是利用勘探所公益性科研专项正执行的项目研究成果"深孔高温磁中靶仪器"引导对接连通的,体现了科研成果转化为生产力的迅速性,这种工业生产与科研成果紧密结合的模式对勘探所今后的科研工作起到了较强的示范作用。天然碱矿是一种可溶性较差的非金属矿产,河南安棚天 相似文献
67.
High-sensitivity and wide-directivity ultrasound detection using high Q polymer microring resonators 总被引:1,自引:0,他引:1
Small size ultrahigh Q polymer microrings working at near visible wavelength have been experimentally demonstrated as ultralow noise ultrasound detectors with wide directivity at high frequencies (>20 MHz). By combining a resist reflow and a low bias continuous etching and passivation process in mold fabrication, imprinted polymer microrings with drastically improved sidewall smoothness were obtained. An ultralow noise-equivalent pressure of 21.4 Pa over 1-75 MHz range has been achieved using a fabricated detector of 60 μm diameter. The device's wide acceptance angle with high sensitivity considerably benefits ultrasound-related imaging. 相似文献
68.
70.