土壤环境容量数学模型——Ⅰ.土壤污染动力学模型

应用物质平衡原理,导出模拟土壤污染过程的动力学方程.可用于估算土壤环境容量、分析土壤污染动态和预测土壤超容年限.以测定残留率为基础的一类模型是本文提出的模型的一个特例.     

城郊道路交通污染个例分析

为建立和研究适合地面道路的宽路幅、高等级、支路多等特点的大城市城郊道路交通大气污染扩散模式,选取了受环境外来源影响较小的上海市沪青平公路的徐泾段,作交通大气污染实测和相关气象因子项目的观测。在获得详细实测结果的基础上,以NOx为例分析了大气稳定度、风向、风速、交通量对城郊地面道路交通污染扩散的影响。     

诱导动力学-停流流动注射光度法测定水中铁的价态分布

依据Ｆｅ（Ⅱ）－Ｃｒ（Ⅵ）－Ⅰ＾－氧化还原反应的诱导作用,提出了诱导动力学－停流光度法测定Ｆｅ（Ⅱ）的方法并建立了测定条件：〔Ｃｒ（Ⅵ）〕＝１．８×１０＾－３ｍｌｌ·Ｌ＾－１,〔Ⅰ〕＝２．０×１０＾－２ｍｏｌ·Ｌ＾－１,ｐＨ＝１．９,５９０ｎｍ;在此条件下,线性范围为０－２．２μｇ·ｍＬ＾－１,检测限为０．００９μｇ·ｍＬ＾－１Ｆｅ（Ⅱ）;２５倍的Ｆｅ（Ⅲ）对测定无干扰。测定Ｆｅ（Ⅲ）后,将Ｆｅ（     

流动注射-分光光度法测定工业废水中的Fe^2＋和Fe^3＋

将Fe^2 与邻菲啰啉的显色反应引入流动注射系统，用盐酸羟胺将Fe^3 预先还原，0～6μg/ml的Fe^2符合比耳定律，检测出限0．11μg／ml。0．25μg／mlFe^2 经5次测定的标准偏差为2．2％，进样频率为120次／h，回收率98．5～104％。对工业废水中铁的测定取得了满意的效果。     

Transcervical CVS sample size: Correlation with placental location,cytogenetic findings,and pregnancy outcome

Data from 2907 transcervical CVS cases performed on singleton pregnancies were reviewed retrospectively and villus sample size was correlated with cytogenetic results, placental location, maternal age at the expected date of confinement (EDC), gestational age at the time of sampling, birth weight, gestational age at the time of delivery, and pregnancy outcome. No correlation was noted between villus sample size and maternal age, gestational age at sampling, gestational age at delivery, birth weight, or pregnancy outcome. An inverse correlation between villus sample size and percentage of abnormal cytogenetic findings was statistically significant (X² = 8·53, p <0·01). The percentage of small samples was greater when the placenta was anterior, lateral, or fundal than when the placenta was posterior.     

Effects of nano-copper(II) oxide and nanomagnesium oxide particles on activated sludge

Effects of nano-copper(II) oxide (nano-CuO) and nanomagnesium oxide (nano-MgO) particles on activated sludge endogenous respiration (aerobic digestion), biochemical oxygen demand (BOD) biodegradation, and nitrification were investigated through respiration rate measurement. For comparison, the effects of Cu(II) and Mg(II) ions on activated sludge were also studied. Results indicated that soluble Cu(II) has half maximum inhibitory concentration (IC50) values of 19, 5.5, 53, and 117 mg Cu/L for endogenous respiration, BOD biodegradation, ammonium oxidation, and nitrite oxidation, respectively. However, nano-CuO only inhibited BOD biodegradation at 240 mg Cu/L or more, and its associated toxicity was primarily caused by soluble Cu(II). In contrast, soluble Mg(II) was not toxic to activated sludge in the experimental concentration range, but nano-MgO inhibited BOD biodegradation and nitrification with IC50 values of 70 and 143 mg Mg/L, respectively. Further study indicated that the toxicity of nano-MgO resulted primarily from increased pH following MgO hydrolysis.     

美国的环境立法

通过对美国环境立法发展状况的分析,阐述了美国环境法规的特点,及其在国家加强行政环境管理等方面的作用。立法不完善,是美国环境立法的主要问题。     

浅谈上海地区的总稀土

1 概述稀土(Rare Earth)元素,位于元素周期表第57～71号,由性质十分相近的镧、铈、镨、钕等15种镧系元素以及钪、钇2个元素组成。通常,把57～63号的7个元素称为轻稀土元素,其它10个元素称为重稀土元素。地壳中,稀土元素含量与锌、铜、铅等元素含量不相上下。我国的稀土资源,居世界首位,共约3600万吨(R_2O_3),其中90％分布在包头地区。土壤及生物链中,均有稀土元素。进入环境中的稀土化合物,大部分来自岩石的风化物,其次来自煤的燃烧。稀土元素,主要用于冶金、石油化工、电子器械、玻璃陶瓷等工业上。稀土元素,通过口、呼吸道及皮肤的伤口进入人体。吸收后的稀土元素,从人体内排泄的半衰期为一年至十几年。