金属浓度,半透膜孔径,水温及配位体对半透膜囊吸收铜的影响

在实验室条件下，研究了影响树脂－半透膜囊吸收铜的主要因素，重点探讨了水相铜含量，半透膜孔径，温度以及天然河水中的有机配位体对吸收的影响。结果表明，半透膜囊吸收量与水相游离铜浓度，水温及半透膜孔径的非整数次幂成正比，其中包括ＥＤＴＡ，河水富里酸，以及河水中的各种天然有机物在内的配位体均与铜生成不能被半透膜囊吸收的络合物，研究结果进一步证实了半透膜囊对水环境中游离态微量金属进行长期监测的可行性。     

白腐真菌对土壤中多环芳烃(PAHs)降解的研究

研究白腐真菌对多环芳烃(PAHs)的降解,结果表明,温度、培养基、氧气浓度、水土比对PAHs的降解均有影响.温度为25℃、营养液为查氏培养基、通气量为60L·d-1、水土比为5∶1为最优水平组合.对降解不同时期各种因素的重要性及其最优水平的分析表明,各种影响因素在降解实验的不同阶段的影响程度不同,降解实验初期,培养基是最重要的影响因素,而氧气在整个实验中均为重要的影响因素.     

土壤中不同老化时间的DDT对小麦根系的生物有效性

研究了水、正己烷、正己烷/丙酮ASE对土壤中不同老化时间的DDT的逐级提取量的差别及其与小麦根吸收的关系。结果表明,有机氯的水提量随老化时间增加而下降,正己烷提取量随老化时间增加而下降,正己烷/丙酮提取量随老化时间增加而上升。植物根吸收随老化时间增加而下降。根吸收与水提量没有确定关系,与正己烷提取量具正相关关系,与正己烷/丙酮提取量有负相关关系。正己烷提取量可被作为土壤有机氯DDT的有效态部分。     

氢氧化镁处理含镉废水的研究

以氢氧化镁作为吸附剂处理含镉酸性废水。结果表明，氢氧化镁对Cd^2 的吸附为化学吸附，去除率一般可达98％以上。氢氧化镁回收后，经轻烧处理变成氧化镁，仍可以处理含镉废水，且可多次使用。     

鲤鱼鱼鳃粘液对铜的络合特征

用络合滴定法研究了鲤鱼鱼鳃粘液对铜的络合特性 ,并根据实测数据考察了不同拟合方法的优劣 .结果表明 ,在选定的滴定范围内 ,单配体模型可以很好地描述粘液和铜之间的相互作用 .各种拟合方法中 ,常用的经线性变换的Scatchard方法误差最大 ,其余方法相差不大 .对这些方法进行一次迭代可以大大改善拟合精度和稳健性 .由此得到的条件稳定常数为 7 0 5 ,络合容量为 0 1 5 8μmol·mg- 1C .     

农业生产活动对鄱阳湖区生态环境的影响

鄱阳湖区是江西省重要商品粮基地，但其生态环境也有较为脆弱的一面。某些违反生态规律的农业生产活动导致该区生态环境的恶化。本文从围湖造田、湖区传统耕作制度、乡镇企业发展及农民环境意识淡薄等方面分析了它们对湖区生态环境的影响，并提出几点治理意见。     

Distribution and Fractionation of Copper in Soils of Apple Orchards (5 pp)

Background Frequent application of Bordeaux mixture, which includes copper, as a fungicide in fruit and grape orchards may lead to copper accumulation in the soil, especially when orchard age and application times increase. The objectives of this study were: (i) to investigate the copper content and its spatial distribution in orchard soils; (ii) to identify the copper fractionation in soil and its relationship with plant uptake; (iii) to understand the characteristics of copper contamination in orchard soils. Materials and Methods Soil profile samples were taken in apple orchards with ages of 0, 5, 10, 20, 30 years and pot experiments were also carried out to study the effects of external copper input on copper fractionation. All soil samples were air-dried, ground and extracted with 0.43 mol L–1 HNO3 for the total absorbed copper. Fractionation determination was conducted following Tessier and Shuman sequential extraction methods, and copper was measured with AAS. Plant samples were first dry ashed, dissolved with 6 mol L–1 HCl and then copper and other elements were measured with ICP-MS.Results and Discussion Soil total Cu was higher in the apple orchards than that in non-orchard fields and was seen to have increased with orchard age. Soil Cu increased substantially with the average annual copper increase, ranging from 2.5 to 9 mg Cu kg–1. The distribution of copper in the soil profile was uneven, decreasing from surface to deeper layers, and the differences were significant, but the contents in every layer were also significantly correlated with those in the next layers. For all copper fractions, the organically bound, crystalline Mn oxide bound, and amorphous Fe bound fractions extracted with the Shuman method were much higher than the exchangeable and residual fractions. Using the Tessier method, organically bound, carbonate bound and Fe-Mn oxide bound fractions were much higher. With an increase in external copper input, the organically bound, crystalline Mn oxide bound and amorphous Fe bound fractions in the Shuman method and organically bound, carbonate bound and Fe-Mn oxide bound fractions in the Tessier method all increased significantly, while the changes in other fractions were not significant. Soil total copper and copper fractions were found to have good correlations with apple tree uptake. Copper in fruit flesh had significant correlations with soil total content in the 0–10 cm layer, all the copper fractions in the 0–5 cm layer, and some fractions in the deeper layers. Conclusion Copper content in orchard soils increased significantly with intensive application of Bordeaux mixtures and orchard age. Copper content decreased sharply from the topsoil to deeper soil layers. The copper contents in different layers also significantly correlated with those in the next layers. Dominant fractions of the copper in soil were mainly associated with organic matter, iron and manganese oxides and carbonates. A close relationship was found between the copper content in soils and in apple tree organs (which contained 8.9 to 66mg kg–1 Cu). Recommendation and Perspective Though most copper in the soil was specifically adsorbed or immobilized, and copper was mainly distributed in topsoil, which was essentially devoid of roots, the copper concentration of fruit still had significantly positive correlations with soil copper and most copper fractions. Therefore, measures must be taken to control copper accumulation in orchard soils and to make the apple fruit production sustainable.     

Synchronous-scan fluorescence spectra of Chlorella vulgaris solution

The characterization of the Chlorella vulgaris solution was carried out using synchronous-scan spectroscopy. The range of concentration of algae and Fe(III) in aqueous solutions were 5 × 10⁸–8 × 10⁹ cells l⁻¹ and 10–60 μM, respectively. Effective characterization method used was synchronous-scan fluorescence spectroscopy. The wavelength difference (Δλ) of 90 nm was maintained between excitation and emission wavelengths; 90 nm was found to be the best Δλ for effective characterization of Chlorella vulgaris solution with or without quencher species (e.g., Fe(III), humic acid (HA)) for the first time. The peak was observed at about EX 236.6 nm/EM 326.6 nm for synchronous-scan fluorescence spectra. The fluorescence quenching of algae in system of algae–Fe(III)–HA was studied using synchronous-scan spectroscopy for the first time. Fe(III) was clearly the effective quencher. The relationship between I₀/I (quenching efficiency) and c (concentration of Fe(III) added) was a linear correlation for the algae solution with Fe(III). Also, Aldrich humic acid was found to be an effective quencher. pH effect on synchronous-scan fluorescence intensity of algal solution with Fe(III) and/or HA was evident.     

长江、嘉陵江(重庆段)源水有机提取物的致突变活性及其季节变化

为了确定并比较重庆主城区段长江、嘉陵江源水有机提取物的致突变性及其季节变化规律，分别于春、夏、冬季采用GDX－120大孔树脂，对位于城区上游、城区中段、城区下游以长江、嘉陵江源水的5个水厂的进厂水进行了有机物的浓缩提取。提取物的致突变活性采用经典的Ames试验平板掺入法评估，测试菌株为TA98及TA100，同时做加与不加S9的比较。结果显示，嘉陵江及长江源水的有机提取物均有不同程度的致突变活性。嘉陵江源水明显大于长江源水，城区中段源水明显大于上游段及下游段源水。多数断面显示平水期致突变活较为显著并且移码型致突变性大于碱基置换型致密变性。研究结果提示，城市污染源已导致长江、嘉陵江源水具备致突变活性，控制两江沿岸的各种水污染源已成为当务之急。     

造纸黑液酸析法回收木质素

研究了加酸沉淀回收碱法草浆黑液中木质素的工艺,探讨了酸浓度,温度,ｐＨ值及加酸速度对木质素回收量的影响,得出的最佳条件是：硫酸浓度为５０％,温度为４０℃￣５０℃,ｐＨ值为３．０左右,加酸速度以控制不使产生大量泡沫为准。在上述条件下,木质素的回收效果最佳。