粘土,硅藻土,聚乙烯瓶和玻璃瓶对碘的吸附行为

本文以Na~(125)I为示踪剂,在模拟地下水介质条件下研究了粘土和硅藻土对长寿命裂变产物~(129)I(T_(1/2)=1.57×10~7a)的吸附规律。实验发现,在pH6—7的地下水介质中,粘土和硅藻土对I~-的吸附服从Freundlich等温吸附经验公式,但吸附百分率较小(≤5％)。 对无载体~(125)I在实验用聚乙烯瓶和玻璃瓶上的吸附研究表明,碘的氧化态(I_3~-或IO_3~((?))要比I~-更易被吸附。     

Stock structure of the southern bluefin tuna Thunnus maccoyii: an investigation based on probe microanalysis of otolith composition

Analysis of the chemistry of calcified tissues has been suggested to be a source of useful information on the population structure and environmental history of fishes. We have investigated this approach as a means of determining the number of spawning areas and diversity of migration routes in the large pelagic scombrid, Thunnus maccoyii (southern bluefin tuna). Analysis was based on ontogenetic variation in the composition of sagittal otoliths, as measured using two probe microanalysers (wavelength dispersive electron probe microanalysis and proton-induced X-ray emission microanalysis), of 9 larvae collected on the single known spawning ground (NE Indian Ocean), of 29 juveniles caught at different points along the known migration routes (off western Australia, southern Australia, and South Africa), and of 14 adults caught in the high-seas fishery (off SE Australia). Fifteen elements were detected in T. maccoyii sagittae, but only six (Ca, Na, Sr, K, S, and Cl) were consistently present at concentrations above minimum detection limits. No attempt was made to measure the concentrations of C, N and O, which are assumed to also be present. Comparisons among different samples indicated that: (1) variation in the composition of the otolith primordium was unimodal and, generally, normally distributed; (2) this composition varied among specimens as a function of their size or, apparently, year-class; (3) individuals collected from widely separated locations did not differ clearly in the composition of the most recently deposited sections of their otoliths; and (4) all variation in the composition of adult otoliths was encompassed in the range of variation of juveniles collected along the major known migration route. These observations are consistent with the hypothesis of a single spawning area for T. maccoyii, but also indicate that the range of environmentally correlated variation in composition is too low to provide a robust test of the diversity of migration routes. It is not clear why this variation is so low, but we suspect that it reflects both the relative homogeneity of the pelagic environment and a weak effect of environmental factors on the concentration of elements present in otoliths at levels1 ppm.     

利用回归方程对沼气发生量的预测

示了沼气发生量与污水二级处理量和污泥沉淀量存在有显著的线性关系，关建立了相应的二元线性回归方程，同时利用标准回归系数判定污泥沉淀量是影响沼气发生量的主要因素。     

Proteomic analysis in Daphnia magna exposed to As(III), As(V) and Cd heavy metals and their binary mixtures for screening potential biomarkers

In this study, the effects of three widespread heavy metals, As(III), As(V) and Cd, and their binary mixtures on the proteomic profile in D. magna were examined to screen novel protein biomarkers using the two-dimensional gel electrophoresis method (2DE). Ten 20d daphnia were exposed to the LC20 concentrations for each of a total of 8 treatments, including the control, As(III), As(V), Cd, [As(III)+As(V)], [As(III)+Cd], [As(V)+Cd], and [As(III), As(V), Cd], for 24 h before protein isolation. Three replicates were performed for each treatment. These protein samples were employed for 2DE experiments with a pH gradient gel strip from pH 3 to pH 10. The protein spots were detected by a silver staining process and their intensities were analyzed by Progenesis software to discover the differentially expressed proteins (DEPs) in response to each heavy metal. A total of 117 differentially expressed proteins (DEPs) were found in daphnia responding to the 8 treatments and mapped onto a 2D proteome map, which provides some information of the molecular weight (MW) and pI value for each protein. All of these DEPs are considered as potential candidates for protein biomarkers in D. magna for detecting heavy metals in the aquatic ecosystem. Comparing the proteomic results among these treatments suggested that exposing D. magna to binary mixtures of heavy metals may result in some complex interactive molecular responses within them, rather than just the simple sum of the proteomic profiles of the individual chemicals, (As(III), As(V), and Cd).     

烟道气中二氧化硫监测质量控制探讨

通过对碘量法测定烟道气中二氧化硫在布点,采样,样品保存等方面的分析,找出了二氧化硫监测结果产生误差的原因,提出了改进方法,进而提高监测数据的准确性和可靠性。     

Assessment of Young Dong tributary and Imgok Creek impacted by Young Dong coal mine,South Korea

An initial reclamation of the Young Dong coal mine site, located in northeastern South Korea, was completed in 1995. Despite the filling of the adit with limestone, acid rock drainage (ARD) enters Young Dong tributary and is then discharged to Imgok Creek. This ARD carries an average of 500 mg CaCO₃/l of mineral acidity, primarily as Fe(II) and Al. Before spring runoff, the flow of Imgok Creek is 3.3–4 times greater than that of the tributary and has an alkalinity of 100 mg CaCO₃/l, which is sufficient to eliminate the mineral acidity and raise the pH to about 6.5. From April through September 2008, there were at least two periods of high surface flow that affects the flow of ARD from the adit. Flow of ARD reaches 2.8 m³/min during spring runoff. This raised the concentrations of Fe and Al in the confluence with Imgok Creek. However, by 2 km downstream the pH of the Imgok Creek is 6.5 and only dissolved Fe is above the Korean drinking water criteria (0.30 mg/l). This suggests only a minor impact of Young Dong Creek water on Imgok Creek. Acid digestion of the sediments in Imgok Creek and Young Dong Tributary reveals considerable abundances of heavy metals, which could have a long-term impact on water quality. However, several water-based leaching tests, which better simulate the bioavailable metals pool, released only Al, Fe, Mn, and Zn at concentrations exceeding the criteria for drinking water or aquatic life.

     

Assessment of Young Dong tributary and Imgok Creek impacted by Young Dong coal mine,South Korea

An initial reclamation of the Young Dong coal mine site, located in northeastern South Korea, was completed in 1995. Despite the filling of the adit with limestone, acid rock drainage (ARD) enters Young Dong tributary and is then discharged to Imgok Creek. This ARD carries an average of 500 mg CaCO₃/l of mineral acidity, primarily as Fe(II) and Al. Before spring runoff, the flow of Imgok Creek is 3.3–4 times greater than that of the tributary and has an alkalinity of 100 mg CaCO₃/l, which is sufficient to eliminate the mineral acidity and raise the pH to about 6.5. From April through September 2008, there were at least two periods of high surface flow that affects the flow of ARD from the adit. Flow of ARD reaches 2.8 m³/min during spring runoff. This raised the concentrations of Fe and Al in the confluence with Imgok Creek. However, by 2 km downstream the pH of the Imgok Creek is 6.5 and only dissolved Fe is above the Korean drinking water criteria (0.30 mg/l). This suggests only a minor impact of Young Dong Creek water on Imgok Creek. Acid digestion of the sediments in Imgok Creek and Young Dong Tributary reveals considerable abundances of heavy metals, which could have a long-term impact on water quality. However, several water-based leaching tests, which better simulate the bioavailable metals pool, released only Al, Fe, Mn, and Zn at concentrations exceeding the criteria for drinking water or aquatic life.