微好氧颗粒污泥工艺降解五氯酚的实验研究

微好氧颗粒污泥工艺能够同时进行好氧氧化和厌氧还原过程，是处理五氯酚（PCP）的理想方法。对影响好氧颗粒污泥降解PCP的因素水力学上升流速、碱加入量以及水力停留时间进行考察。结果表明，水力学上升流速为4.58m／h，进水NaHCO3浓度为900mg／L，水力停留时间为24h时，处理效果比较好。     

Growth factors, kinetics and biodegradation mechanism associated with Pseudomonas nitroreducens TX1 grown on octylphenol polyethoxylates

The growth properties and biodegradation mechanism of a Gram-negative bacterium, Pseudomonas nitroreducens TX1 that was able to grow on branched octylphenol polyethoxylates (OPEO(n), average n=9.5) as the sole carbon source over a wide concentration range (1-100,000 mgl(-1)) were studied. Analysis of growth factors indicated the highest specific growth rate (micro) of 0.53 h(-1) was obtained at an initial concentration of 5,000 mgl(-1) OPEO(n). An optimal C/N ratio of 12 was obtained for (NH(4))(2)SO(4) as the nitrogen source in a cultivated medium at pH 7. The kinetic analysis demonstrated that bacterial growth and OPEO(n) degradation followed the Monod equation and were based on a substrate concentration inhibition model and pseudo-first-order reaction, respectively. The substrate inhibition coefficient was over 18,000 mgl(-1) and this indicates that the strain has an ability to sustain growth at high concentrations of OPEO(n) and use it as the sole carbon source under such a stress condition. Furthermore, LC-MS analysis showed that the biodegradation mechanism of dodecyl octaethoxylate (AEO8) by P. nitroreducens TX1 was the sequential cleavage of the ethoxylate chain.     

长江河口越江工程在上海港建设中的重要作用

探讨了连接上海，崇明和江苏海门的长江河口桥隧工程在连接河口岛屿间交通，发挥崇明的区位优势，促进地区经济发展以及在上海港建设中的作用。详细论述了越江工程完成后上海新港的扩建，根据河口河水岸线的分布，提出了在横沙岛东滩修建人工岛的设想，最后对几种越江方案进行了分析比较，提出了作者的看法。     

黄酒中尿素的测定

二乙酰－肟分光光度法是测定黄酒等样品中尿素含量的一种快速、灵敏、简便的方法。样品中的尿素与显色试剂在沸水浴中发色１０￣１５ｍｉｎ后比色测定，显色的线性范围在０￣９μｇ尿素之间。测得的结果中包含了瓜氨酸的含量。样品中酒精和葡萄糖的存在不干扰测定。以标准加入法进行定量，从而使该方法的回收率和重现性大大提高，可满足一般痕量分析的要求。     

Distribution of Trace Metals in the Surface Sediments of Two Pristine Subalpine Lakes in Taiwan

Sediment cores were collected from two remote subalpine lakes: the rather shallow (1.5 m) Little Ghost Lake at 2040 m elevation and the deeper, Great Ghost Lake (40 m) at 2150 m elevation. Different early diagenesis of metals were observed. the seasonally anoxic hypolimnion drives the annual iron redox cycle and causes the remobilization of metals in the mobile fractions of sediments in the Great Ghost Lake. These result in the redistribution of metals in the mobile fractions of sediment and poor correlation between metal concentrations. in the Little Ghost Lake, the shallow water column is always oxic with less change of metals in the mobile fractions of sediments. As a result, most metals have strong positive correlations with each other.

The distributions of metal/Al ratios, total metal contents and acid-leached metal concentrations in the near-surface sediments of these two lakes suggest that the anthropogenic inputs from the atmospheric fallouts in recent decades are one of the major factors affecting the distributions of metals such as cadmium, lead and, to a lessor extent, zinc. the Pb-206/Pb-207 ratios confirm the anthropogenic lead input in these surface sediments.     

PeLM: modeling of pesticide-losses through runoff and sediment transport

A GIS-aided pesticide loss model (PeLM) was developed to simulate pesticide losses through surface runoff and sediment transport in watershed systems. The PeLM could tackle the movement of eroded soil along with surface runoff as well as the pesticide losses in adsorbed and dissolved phases. The contributions of different soil types in the sediment were also examined. The model was applied to the Kintore Creek Watershed of southern Ontario, Canada. The simulation results were verified through observed data, indicating a correlation level of 0.89-0.98. The results also showed that clay particles usually held the largest share of contributions to pesticide losses through soil erosion. This study is significant in the efforts for modeling nonpoint source pollution in watershed systems. It provides useful information and support for the related decisions of watershed management.     

Microbial degradation of livestock-generated ammonia using biofilters at typical ambient temperatures

The purpose of this research was to neutralize livestock-generated ammonia by using biofilters packed with inexpensive inorganic and organic packing material combined with multicultural microbial load at typical ambient temperatures. Peat and inorganic supporting materials were used as biofiltration matrix packed in a perfusion column through which gas was transfused. Results show the ammonia removal significantly fell in between 99 and 100% when ammonia concentration of 200 ppmv was used at different gas flow rates ranged from 0.030 to 0.060 m3 h(-1) at a fluctuating room temperature of 27.5 +/- 4.5 C (Mean +/- SD). Under these conditions, the emission concentration of ammonia that is liberated after biofiltration is less than 1 ppmv (0.707 mg m(-3)) over the period of our study, suggesting the usage of low-cost biofiltration systems for long-term function is effective at wider ranges of temperature fluctuations. The maximum (100%) ammonia removal efficiency was obtained in this biofilter was having an elimination capacity of 2.217 g m(-3) h(-1). This biofilter had high nitrification efficiencies and hence controlled ammonia levels with the reduced backpressure. The response of this biofilter to shut down and start up operation showed that the biofilm has a superior stability.     

Biological responses of workplace particles and their association with adverse health effects on miners

Epidemiological research has demonstrated the relationship between exposure to quartz dust and an elevated risk of pneumoconiosis and possible elevated risk of cancer. The current study was designed to evaluate the biological responses of workplace particles containing crystalline silica using an in vitro cell test. Respirable particle samples were sampled from four tin mines, where the standardized mortality ratio (SMR) for pneumoconiosis was 51.6 and SMR for lung cancer was 2.2 in dust-exposed miners. Alveolar macrophages (AM) are considered as the target cells for primary dust effects. The samples were then measured at 15, 30, 60 and 120 microg particle per 10(6) AM for cytoxicity with the release of glucuronidase, lactate dehydrogenase, for reactive oxygen damage with H(2)O(2) release, and for ability to induce fibrosis using the secretion of tumor necrosis factor-alpha (TNF-alpha). Pure quartz (DQ12) and corundum were used as controls. The results showed the samples from tin mines caused a higher cytoxicity when compared to corundum, yet lower when compared to quartz. However, reactive oxygen species release (148-177 nmol/3 x 10(5) AM in high concentration of 120 microg/10(6) AM) induced by the samples were significantly higher than that induced by quartz (57 nmol/3 x 10(5) AM) and corundum (62 nmol/3 x 10(5) AM). Furthermore, particle samples induced higher TNF-alpha secretion than corundum, the samples from Limu tin mine induced much higher TNF-alpha levels than that induced by DQ12 quartz. The results from the in vitro tests help elucidate the degree of hazard of dust particles in tin mines. The in vitro reaction patterns of AM also constitute a powerful tool to monitor biological and pathogenic responses of humans following dust particle exposure.     

NEW STRATEGIES FOR AGRICULTURAL DEVELOPMENT IN CHINA''''S MOUNTAIN AREAS

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Lead phytoextraction from contaminated soil with high-biomass plant species

In this study, cabbage [Brassica rapa L. subsp. chinensis (L.) Hanelt cv. Xinza No 1], mung bean [Vigna radiata (L.) R. Wilczek var. radiata cv. VC-3762], and wheat (Triticum aestivum L. cv. Altas 66) were grown in Pb-contaminated soils. Application of ethylenediaminetetraacetic acid (EDTA) (3.0 mmol of EDTA/kg soil) to the soil significantly increased the concentrations of Pb in the shoots and roots of all the plants. Lead concentrations in the cabbage shoots reached 5010 and 4620 mg/kg dry matter on Days 7 and 14 after EDTA application, respectively. EDTA was the best in solubilizing soil-bound Pb and enhancing Pb accumulation in the cabbage shoots among various chelates (EDTA, diethylenetriaminepentaacetic acid [DTPA], hydroxyethylenediaminetriacetic acid [HEDTA], nitrilotriacetic acid [NTA], and citric acid). Results of the sequential chemical extraction of soil samples showed that the Pb concentrations in the carbonate-specifically adsorbed and Fe-Mn oxide phases were significantly decreased after EDTA treatment. The results indicated that EDTA solubilized Pb mainly from these two phases in the soil. The relative efficiency of EDTA enhancing Pb accumulation in shoots (defined as the ratio of shoot Pb concentration to EDTA concentration applied) was highest when 1.5 or 3.0 mmol EDTA/kg soil was used. Application of EDTA in three separate doses was most effective in enhancing the accumulation of Pb in cabbage shoots and decreased mobility of Pb in soil compared with one- and two-dose application methods. This approach could help to minimize the amount of chelate applied in the field and to reduce the potential risk of soluble Pb movement into ground water.