沟渠式生物接触氧化法对有机物和氨氮的去除研究

生物接触氧化工艺是目前较为成熟的水质净化技术,国内外在河流水质净化、水体修复中都有较多的研究和应用.在实验室采用沟渠式生物接触氧化组合系统处理模拟村庄面源污水,较好地去除了有机物并实现氨氮转化.结果表明,当进水COD为130～290mg/L、氨氮为30～40mg/L、水力负荷为0.19～0.24m3/(m2·d)的条件下,该系统稳定运行11周,COD和氨氮的平均去除率分别达85%和79%.     

生物絮凝剂MBFGA1预处理乳制品加工废水

用生物絮凝剂MBFGA1预处理乳制品加工废水（简称废水）。实验结果表明，废水处理的水力条件为：以150r／min的转速搅拌30S，再以30r／min的转速搅拌20min；MBFGA1的最佳加入量为15mg／L；废水pH为4．0时，MBFGA1对废水的絮凝处理效果最好；废水温度对浊度、COD去除率有一定的影响，在20～45℃时，废水浊度的去除率始终保持在85％以上；30℃时，COD去除率达到最大值65．0％。     

金属加工过程中应力状态的分析方法

分析简单地拉伸、压缩和扭转的情况时,应力状态能容易地被确定.但是,实际上在金属加工过程中材料是承受复杂的应力状态,在模具——工件接触面上增加有摩擦力.而且,这些应力和摩擦力一般地沿着接触面变化.准确的计算或预测载荷、力、应力和温度,不但对设计适宜的设备是重要的,而且对研究工艺期间材料的变化过程也是重要的.本文将讨论材料变形过程中所运用的主要分析方法及其优缺点.     

Photodegradation of TCDD in soil containing organic solvents

Studies were conducted to understand 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) behaviour in the near surface zone in relation to the operating conditions: UV-intensity, temperature and exposure modes. Comparisons have been made between Oriel lamp exposure tests and sunlight exposure tests. Under Oriel lamp exposure, the convective transport of TCDD, which depends on operating temperature, was the limiting factor in the cleanup process. The product differences between Oriel exposure tests and sunlight exposure tests probably result from the difference of UV-intensities.     

Contamination of Canadian and European bottled waters with antimony from PET containers

Using clean lab methods and protocols developed for measuring Sb in polar snow and ice, we report the abundance of Sb in fifteen brands of bottled water from Canada and forty-eight from Europe. Comparison with the natural abundance of Sb in pristine groundwaters, water bottled commercially in polypropylene, analyses of source waters prior to bottling, and addition of uncontaminated groundwater to PET bottles, provides unambiguous evidence of Sb leaching from the containers. In contrast to the pristine groundwater in Ontario, Canada containing 2.2 +/- 1.2 ng l(-1) Sb, 12 brands of bottled natural waters from Canada contained 156 +/- 86 ng l(-1) and 3 brands of deionized water contained 162 +/- 30 ng l(-1); all of these were bottled in PET containers. Natural water from Ontario bottled in polypropylene contained only 8.2 +/- 0.9 ng l(-1). Comparison of three German brands of water available in both glass bottles and PET containers showed that waters bottled in PET contained up to 30 times more Sb. To confirm that the elevated Sb concentrations are due to leaching from the PET containers, water was collected in acid-cleaned LDPE bottles from a commercial source in Germany, prior to bottling; this water was found to contain 3.8 +/- 0.9 ng l(-1) Sb (n = 5), compared with the same brand of water purchased locally in PET bottles containing 359 +/- 54 ng l(-1) (n = 6). This same brand of water in PET bottles, after an additional three months of storage at room temperature, yielded 626 +/- 15 ng l(-1) Sb (n = 3). Other German brands of water in PET bottles contained 253-546 ng l(-1) Sb (n = 5). The median concentration of Sb in thirty-five brands of water bottled in PET from eleven other European countries was 343 ng l(-1) (n = 35). As an independent check of the hypothesis that Sb is leaching from PET, the pristine groundwater from Canada (containing 2.2 +/- 1.2 ng l(-1) Sb) was collected from the source using PET bottles from Germany: this water contained 50 +/- 17 ng l(-1) Sb (n = 2) after only 37 days, even though it was stored in the refrigerator, and 566 ng l(-1) after six months storage at room temperature.     

The Influence of Chironomus plumosus Larvae on Nutrient Fluxes and Phosphorus Fractions in Aluminum Treated Lake Sediment

One of the methods to diminish the internal phosphorus (P) loading is inactivation of P by aluminum (Al). After addition of Al to lake water an Al(OH)₃ floc is formed, which settles to the bottom and initially form a lid on the sediment surface. The effects of Chironomus plumosus larvae on sediment nutrient fluxes and P binding-sites in the sediment after addition of Al were tested. C. plumosus larvae were added to sediment cores in which sediment–water fluxes of nutrients were measured four times. After one month, the sediment was sectioned with depth and P fractions were measured by sequential chemical extraction. The chironomids created burrows through the Al layer which caused a significantly increased efflux of P from the Al treated sediment, because the P had only limited contact to the added Al. The chironomids also affected the P fractions in the sediment by their bioturbating activity. Thus, they caused increased Al concentrations in the upper part of the Al treated sediment. This created an enhanced contact between Al and P in the upper 7 cm of the sediment and, as a result, an increased binding of P to Al and a lowered porewater P. The DIP efflux is therefore expected to be lowered after the initial phase. Al had no effects on the nitrogen fluxes, but the chironomids enhanced the release, and decreased the release or increased the uptake by the sediments.     

Distribution of antifouling biocides in California marinas

Antifouling biocides are used to prevent the settlement and growth of organisms on submerged surfaces. Irgarol 1051 is currently among the most widely used organic booster biocides worldwide. This study reports Irgarol 1051, its major metabolite M1 (aka GS26575), and diuron concentrations found in selected California marinas. Seasonal water samples (n = 46) were collected during the summer and fall of 2006 from eleven marinas throughout Southern and Northern California. The samples were extracted using solid phase extraction and analysed utilizing liquid chromatography tandem mass spectrometry (LC-MS-MS) with electrospray ionization. All three compounds were detected in all samples, representing a 100% frequency of occurrence and indicating widespread use around the sampled marinas. Irgarol concentrations ranged from 12 to 712 ng L(-1) (average 102 ng L(-1)), M1 concentrations were 1-217 ng L(-1) (average 31 ng L(-1)), and diuron concentrations were 5-27 ng L(-1) (average 13 ng L(-1)). In general, concentrations of both Irgarol (15-712 ng L(-1)) and M1 (1-217 ng L(-1)) were greater in samples collected during the summer, corresponding to the peak of the boating season. The detected diuron concentrations in most cases were greater for fall samples (7-27 ng L(-1)), and probably represented a combination of non-agricultural (rights of way) and agricultural applications of diuron in California. The maximum Irgarol concentration detected in California marinas in summer 2006 (712 ng L(-1)) was five times greater than the Irgarol concentration suggested as the plant toxicity benchmark (136 ng L(-1)). Twenty three percent of samples from California marinas in this study exceeded this benchmark, suggesting that detected Irgarol concentrations may be high enough to cause changes in phytoplankton communities in the sampled marinas.     

水体中钼污染物的迁移转化研究进展

水体的重金属钼污染在中国部分地区已经显现,明确钼迁移转化规律是治理钼污染的基础.在总结水体钼污染形成机制的基础上,综述了水体钼污染物迁移转化的研究进展.其中,在水体胶体对钼的吸附研究方面较深入,酸碱条件和胶体种类是钼迁移转化的主要影响因素.而目前的研究,对尾矿中不同种类原钼矿物迁移转化与环境条件相互作用的关系尚不明确.因此,解决实际钼污染同题还需更深入的系统性探索.