以pH和ORP作为脉冲SBR工艺的实时控制参数

为了实现脉冲SBR深度脱氮的实时控制,以某污水处理厂市政污水为处理对象,考察了脉冲SBR在深度脱氮过程中pH及ORP的变化规律.试验结果表明,pH及ORP的变化规律与脉冲SBR有机物去除、硝化与反硝化过程存在较好的相关关系.可以根据pH和ORP变化曲线上的特征点对脉冲SBR进行实时控制.并考察了污水C/N(COD/NH4 -N)对pH及ORP的变化规律的影响.在硝化过程中,C/N对pH及ORP曲线变化点的出现没有影响;在反硝化过程中,应结合pH值"硝酸盐峰"和ORP"硝酸盐膝"来判断低C/N污水反硝化的终点.在该试验中,出水TN低于2 mg/L,TN去除率可达到96%以上.     

A sensitive monoclonal antibody-based enzyme-linked immunosorbent assay for chlorpyrifos residue determination in Chinese agricultural samples

A monoclonal antibody-based competitive antibody-coated enzyme-linked immunosorbent assay (ELISA) was developed and optimized for determining chlorpyrifos residue in agricultural products. The IC₅₀ and IC₁₀ of this ELISA were 3.3 ng/mL and 0.1 ng/mL respectively. The average recoveries in six agricultural products were between 79.5% and 118.0%, with the intra-assay coefficient of variation being less than 8 %. The limit of detection for all tested products was 30 ng/g. To the best of our knowledge, this assay has the best specificity among all the published research on ELISAs for chlorpyrifos.     

State-wide increase in prenatal diagnosis of klinefelter syndrome on amniocentesis and chorionic villus sampling: Impact of non-invasive prenatal testing for sex chromosome conditions

Background

To analyze population-based trends in the prenatal diagnosis of sex chromosome aneuploidy (SCA) since the availability of non-invasive prenatal testing (NIPT).

Methods

Retrospective state-wide data for all prenatal diagnoses performed <25 weeks gestation from 2005 to 2020 in Victoria, Australia. Non-invasive prenatal testing became locally available from 2012. The prenatal diagnosis rates of SCA as proportions of all prenatal diagnostic tests and all births were calculated. Statistical significance was assessed with the χ² test for trend, with p < 0.05 considered significant.

Results

46,518 amniocentesis and chorionic villus sampling were performed during the study period, detecting 617 SCAs. There was a significant increase in the rate of prenatal SCAs from 5.8 per 10,000 births in 2005 to 8.7 per 10,000 births in 2020 (p < 0.0001). This increase was predominantly due to 47,XXY cases, 91% of which were ascertained via positive NIPT for this condition in 2020. The prenatal diagnosis rate of 47,XXY significantly increased from 0.8 per 10,000 births in 2005 to 4.3 per 10,000 births in 2020 (p < 0.0001).

Conclusion

Screening for SCAs using NIPT has directly led to an increase in their prenatal diagnosis on a population-wide basis, especially 47,XXY. This has implications for clinician education, genetic counselling, and pediatric services.     

空心壳聚糖微球对二甲酚橙的吸附性能研究

以生物可降解的壳聚糖为原料,采用反相悬浮交联法制备了具有空壳结构的壳聚糖微球,通过控制反应条件得到单分散性的微米级微球.通过分光光度法探讨了溶液初始pH、吸附时间、二甲酚橙初始浓度、壳聚糖微球用量及其直径对壳聚糖微球吸附二甲酚橙的影响.结果表明,常温下壳聚糖微球对二甲酚橙的最佳吸附条件为:溶液初始pH为5,吸附时间为2.0 h,二甲酚橙初始质量浓度为32 mg/L,壳聚糖微球用量为0.3 g/L(以每升二甲酚橙溶液计),壳聚糖微球直径为74 靘;在此最佳吸附条件下,采用分光光度法对二甲酚橙模拟废水进行测定,相应的回收率误差均在-1%～1%.     

Distribution and variation of mercury in frozen soils of a high-altitude permafrost region on the northeastern margin of the Tibetan Plateau

Environmental Science and Pollution Research - The Tibetan Plateau (TP) is home to the largest permafrost bodies at low- and mid-latitudes, yet little is known about the distribution and variation...     

Energy-Saving Effect Calculation and Implementation Strategy Study on the Industrial Structure Adjustment in Western China

The western region is an important strategic base of energy in China. The average per capita possession of fossil energy in the west is twice that in China. On the basis of the analysis of the mechanism how industrial structure adjustment affects energy consumption per unit of gross domestic product (GDP), the energy input-output table of western China was designed and compiled. Combining multiobjective planning techniques, setting energy-saving, economic growth, and laborer's income growth as the goals, setting basic input-output relations, production capacity, and labor as the constraints, the multiobjective optimization model of western energy input-output was constructed. The results of industrial structure optimization of western China show that: with technology and product price remaining unchanged, the adjustment of the industrial structure can reduce energy consumption per unit GDP by 2.7%, at the same time ensuring the average annual increase of GDP and laborer's income of western region in excess of 8%. It indicates that industrial structure adjustment is an effective method in accomplishing the aim of energy saving. Finally, policy suggestions from four angles, such as industrial chain and financial policies, were put forward.     

Innovative cleaner production for steel phosphorization using Zn–Mn phosphating solution

Phosphating prior to coating for steel is usually needed. In this paper, an innovative cleaner production has been developed for steel surface treatment using Zn–Mn phosphating solution in which there was no nitrite. The mass of the Zn–Mn layer deposited in this new process was about 1.1 g m^?2 when the temperature ranged from 3 to 35 °C. The corrosion time for the color phosphating layer in the copper sulfate spot test was in the range of 72–145 s. Adhesion test showed that the coating layers achieved a higher adhesion load than those produced by conventional methods. Washing using water was not necessary in this cleaner phosphorization, which usually follows phosphorization in traditional processes of steel phosphorization. Consequently, wastewater discharge was reduced greatly.     

实验室检测/校准方法的确认研究

结合实验室方法确认工作中的经验,从方法确认的内容、过程、结果以及记录的形成等方面,阐述了实验室方法确认工作有效开展的保障措施。