Association of exposure to multiple metals with papillary thyroid cancer risk in China

Papillary thyroid cancer (PTC) has inflicted huge threats to the health of mankind. Metal pollution could be a potential risk factor of PTC occurrence, but existing relevant epidemiological researches are limited. The current case-control study was designed to evaluate the relationships between exposure to multiple metals and the risk of PTC. A total of 262 histologically confirmed PTC cases were recruited. Age- and gender-matched controls were enrolled at the same time. Urine samples were used as biomarkers to reflect the levels of environmental exposure to 13 metals. Conditional logistic regression models were adopted to assess the potential association. Single-metal and multi-metal models were separately conducted to evaluate the impacts of single and co-exposure to 13 metals. The increased concentration of urinary Cd, Cu, Fe, and Pb quartiles was found significant correlated with PTC risk. We also found the decreased trends of urinary Se, Zn, and Mn quartiles with the ORs for PTC. These dose-response associations between Pb and PTC were observed in the single-metal model and remained significant in the multi-metal model (OR_25-50th=1.39, OR_50-75th=3.32, OR_>75th=7.62, p for trend <0.001). Our study suggested that PTC was positively associated with urinary levels of Cd, Cu, Fe, Pb, and inversely associated with Se, Zn, and Mn. Targeted public health policies should be made to improve the environment and the recognition of potential risk factors. These findings need additional studies to confirm in other population.

     

一体化间歇曝气完全混合活性污泥法

一体化间歇曝气完全混合活性污泥法处理装置采取特殊的沉淀区构造,改变了活性污泥的循环流动方式,通过间歇曝气,反应区交替处于好氧/缺氧状态,达到了有机物高效去除、高效硝化反硝化及控制污泥膨胀的效果.该方法具有出水水质好、运行稳定、能耗低、流程简洁和操作管理方便的特点,是一种很有发展潜力的一体化中小型生活污水、城市污水处理系统.     

A comparative study of the effects of chloride, sulfate and nitrate ions on the rates of decomposition of H2O2 and organic compounds by Fe(II)/H2O2 and Fe(III)/H2O2

The effects of chloride, nitrate, perchlorate and sulfate ions on the rates of the decomposition of hydrogen peroxide and the oxidation of organic compounds by the Fenton's process have been investigated. Experiments were conducted in a batch reactor, in the dark at pH < or = 3.0 and at 25 degrees C. Data obtained from Fe(II)/H2O2 experiments with [Fe(II)]0/[H2O2]0 > or = 2 mol mol(-1), showed that the rates of reaction between Fe(II) and H2O2 followed the order SO4(2-) > ClO4(-) = NO3- = Cl-. For the Fe(III)/H2O2 process, identical rates were obtained in the presence of nitrate and perchlorate, whereas the presence of sulfate or chloride markedly decreased the rates of decomposition of H2O2 by Fe(III) and the rates of oxidation of atrazine ([atrazine]0 = 0.83 microM), 4-nitrophenol ([4-NP]0 = 1 mM) and acetic acid ([acetic acid]0 = 2 mM). These inhibitory effects have been attributed to a decrease of the rate of generation of hydroxyl radicals resulting from the formation of Fe(III) complexes and the formation of less reactive (SO4(*-)) or much less reactive (Cl2(*-)) inorganic radicals.     

INVESTIGATION OF TURBIDITY MAXIMUM IN A MESOTIDAL ESTUARY,TAIWAN1

ABSTRACT: To comprehend the distributions of salinity, temperature, and suspended sediment in the Danshuei River estuary in Taiwan, monthly field surveys were conducted in 2003. These included several high and low slackwater surveys and intensive surveys. The results show that the Danshuei River estuary is predominately a partially mixed estuary. The highest concentration of suspended sediment is typically observed at the Chung‐Hsin Bridge, the most upstream sampling station. The suspended sediment concentration exhibits a general decreasing trend in the downstream direction. It may be concluded that the sediments mostly come from the upstream reach. A locally high concentration of suspended sediment is found at the Kuan‐Du station because of the local deep channel bathymetry and two‐layered estuarine circulation. A vertical two‐dimensional hydrodynamic and sediment transport model is applied to investigate the tidally averaged salinity distribution, residual circulation, and suspended sediment concentration. The modeling results reveal that, under the Q₇₅ flow condition (i.e., low flow), a turbidity maximum occurs at the Kuan‐Du station due to the strong estuarine circulation. The model simulation with a much higher river flow condition results in a weaker residual circulation and weaker turbidity maximum.     

A/O~2法在炼油污水处理中的应用

为探索Ａ／Ｏ２（厌氧Ａｎａｅｒｏｂｉｃ／好氧Ｏｘｉｃ／好氧Ｏｘｉｃ）法在处理炼油污水中的应用,进行了Ａ／Ｏ２法中型试验,验证ＮＨ３－Ｎ容积负荷与去除率之间的关系,以及溶解氧、含油量对处理效果的影响等几项内容。Ａ／Ｏ２法应用于炼油污水的处理是可行的,对ＣＯＤ、ＮＨ３－Ｎ、油、酚、ＳＳ等有很好的处理效果。将Ａ／Ｏ２法应用于济南炼油厂,各构筑物运转正常,处理效果很好,完全达到国家排放标准。Ａ／Ｏ２用来处理炼油污水,工艺可行、技术先进、经济合理,不仅对ＣＯＤ、氨氮去除率高,对其它排放指标去除率都很高。实践证明Ａ／Ｏ２法用来处理炼油污水是完全可行的,济南炼厂污水处理的成功经验值得推广。     

呼伦湖自净功能及其在区域环境保护中的作用分析

在大量详实资料和调查基础上,论述了呼伦湖富营养化状况,找出了该湖富营养化的影响因素,以及其较强自净功能的成因。呼伦湖地处内陆区高纬度、半干旱气候地区,属牧业污染型,氮入湖量主要来源于点源污染(河流的输入),磷入湖量面源(主要是降尘)大于点源。经多年观测发现,氮和磷的变化并不明显,反映出湖体有较强的自净功能,这是和湖体特殊的地理位置分不开的:①该湖系构造湖与河流沟通的吞吐湖,面积大,水较深,使得湖体自净功能显著;②地处高纬度、半干旱地区,气温低,对湖体浮游生物有一定的抑制作用;③湖体构造特殊,露出30余个泉点,有大量地下水的补给。呼伦湖是一个较大的水体与其周围湿地构成的淡水湖泊生态系统,在维持生物多样性和丰富的生物资源方面发挥巨大作用,且有明显的调蓄洪水的功能,在区域环境保护中具有特殊的地位。     

盘式曝气器的结构优化设计

盘式曝气器是目前城市污水处理厂主要采用的曝气设备之一.但目前盘式曝气器存在充氧能力低、阻力损失大、使用寿命短等技术问题,增加了城市污水处理厂运行成本,降低了运行效能.针对这些问题,对盘式曝气器进行了结构优化设计.通过结构优化,既改善了曝气器的抗撕裂性和自闭性,同时又提高了充氧能力,降低了曝气阻力损失.     

活性碳纤维吸附废气中的丙烯酸和甲苯

采用动态吸附法探讨了在活性碳纤维对模拟废气中丙烯酸和甲苯的吸附过程中,各因素对活性碳纤维穿透吸附量和饱和吸附量的影响。实验结果表明,在模拟废气中丙烯酸质量分数为0.2%、双柱塞泵流量为6.1mL/h、载气流量为1.60L/min的条件下,穿透时间为10min,活性碳纤维的穿透吸附量为227.5mg/g,饱和吸附时间为40min,活性碳纤维的饱和吸附量为460.0m g/g。     

航空发动机热端部件表面高温陶瓷涂层性能优化

目的 对航空发动机热端部件表面长效防护涂层W-200进行改进,研制高温稳定性更好且不易崩瓷的高温合金表面新型高温陶瓷涂层,解决W-200涂层在部分高温合金表面暴露出的易崩瓷、剥落问题。方法 通过调整膨胀系数、软化温度、析晶温度,来研制新型耐高温玻璃和耐高温填料,并制备新的高温陶瓷涂层浆料。结果 所研制的新型高温陶瓷涂层W-400能够满足在高温合金表面1 150~1 230 ℃顺利烧结,且具有更大的膨胀系数,可与高温合金基材的膨胀系数更匹配。同时,W-400的析晶温度区间为868~ 1 213 ℃,在析晶温度区间,涂层较W-200具有更好的高温稳定性,以及更优的抗热震、抗剥落性能,并可覆盖实际应用的温度范围。结论 新型高温陶瓷涂层W-400解决了目前W-200高温陶瓷涂层在航空发动机高温合金热端部件表面烧结后易崩瓷的问题。根据本项目的研究基础,对未来可研制出能够在其他金属表面1 250~1 400 ℃顺利烧结的耐温更高的新型高温陶瓷涂层提供了可能性。