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。     

胡椒养分含量状况的研究

胡椒大、中量元素的含量在不同树龄中有所不同，幼龄期以氮最高，其Ｎ：Ｐ２Ｏ３：Ｋ２Ｏ：Ｃａ：Ｍｇ为１：０．１５：０．５３－０．９：０．２２－０．３８：０．１５－０．３０；成年龄则以Ｋ２Ｏ最高，Ｎ：Ｐ２Ｏ３：Ｋ２Ｏ：Ｃａ：Ｍｇ为１：０．１３：１．３２：０．４４：０．１６．在不施微肥的情况下，胡椒叶片缺Ｂ、Ｍｏ、Ｚｎ．成年龄胡椒各养分含量都是从萌芽期（收获后）开始，随生育期的进展而增加，到果实成熟期下降．一株中产胡椒Ｎ、Ｐ２Ｏ５、Ｋ２Ｏ总吸收量为２８２．４ｇ，其比例为１：０．１９：０．９．     

环境样品前处理技术及其进展（二）

在前文中讨论了环境样品的制备、前处理的概况，以及超临界流体萃取法。本文将继续报导近年来环境样品制备与前处理领域中其他一些新技术和新方法，包括固相萃取（ＳＰＥ）、微波溶出（ＭＷＤ）和液膜萃取（ＳＬＭ）法，阐述了这些方法的基本原理、操作过程、各种实验参数的影响，及其在环境样品制备与前处理中的应用，并探讨了该领域的发展动向。     

湘南水田施含SO_4~(2-)和Cl~-肥料对作物生长和养分吸收的效应

1990年4—11月,在湖南祁阳中国农科院红壤实验站布置田间试验,比较含SO_4~(2-)和Cl~ -类肥料对作物生长的效应。结果表明,SO_4~(2-)促进早稻和晚稻营养生长,但水稻收获时的稻谷产量以Cl~-肥料处理区较高。两种阴离子对水稻养分吸收无显著差异,但SO_4~(2-)对早稻体内的磷素转化不利,可能是稻谷产量较低的原因之一。     

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.     

纳滤处理含Cr(VI)废水的试验研究

采用纳滤对含Cr(Ⅵ)废水进行试验研究,讨论了初始浓度、pH、浓差极化、共存离子对处理效果的影响.试验结果表明,NF90膜对含Cr(Ⅵ)废水有良好的处理效果,去除率超过了98%,出水Cr(Ⅵ)浓度低于0.5 mg/L,可以达标排放或回用于镀件漂洗.     

高氨氮对厌氧生物法处理城市垃圾渗沥液的影响

研究了高浓度氨氮对厌氧膜生物法处理城市垃圾渗沥液的影响。结果表明，COD去除率、沼气产量、沼气产率、辅酶F420和最大比产甲烷活性均随氨氮浓度的增加而减小；当氨氮浓度〈3600mg/L时，不会对厌氧膜生物反应器的运行产生明显的影响；氨氮对厌氧污泥产甲烷活性的50％抑制浓度为4350mg／L；高浓度氨氮会造成系统VFA浓度增加；当氨氮浓度由4800mg／L降低到2000mg/L后，受重度抑制的厌氧微生物的活性可以在20d里恢复到未受抑制时的活性水平。     

膜-生物反应器混合液性质对膜污染影响的研究进展

膜-生物反应器作为一种新型的污水处理和回用技术,近年来在基础研究和实际应用领域都得到广泛关注,但是影响其长期稳定运行的膜污染问题却一直没有得到深入研究和解决.混合液特性是影响膜污染控制的重要因素,从混合液理化性质(组成、功能、结构和环境因素)和生物学性质(微生物群落结构、微生物功能特征)2个方面进行介绍,综述了目前关于混合液性质与膜污染关系的研究现状.目前的研究虽然取得一定进展,但在相关性分析、群落特征与膜污染关系、污染层形成机理等方面仍存在许多不足.     

两段式生物膜-膜生物反应器的试验研究

试验对传统两段式生物反应器(TSBR)进行了改进，二段采用生物膜-膜生物反应器(BMBR)；在一段HRT=SRT=2．82～4．23h，二段HRT=6．44～9．66h、SRT→∞，每日空曝气8h的运行条件下，对该工艺进行了试验研究。结果表明，系统稳定后，出水水质稳定，CODc、NH4^ -N和TP的去除效率分别为95％、80%和60％以上，膜污染得到了有效控制。     

错流式动态膜-生物反应器中污泥活性的研究

应用错流式动态膜-生物反应器（CDMBR）对己内酰胺废水进行了180d的实验，实验过程中测定反应器的膜出水和上清液的水质，并对污泥进行了耗氧呼吸速率测定。结果表明，上清液COD一直保持在100mg／L以下，而膜出水的则保持在50mg／L以下，膜对上清液的COD去除率达50％，而对氮的去除没有贡献。可溶性细胞产物（SMP）在反应器内容易积累，停留足够的时间后能被生物降解。通过投加抑制剂测定耗氧呼吸速率，发现异养菌、硝化细菌和亚硝化细菌的活性由于F／M的降低和SMP积累受到一定的抑制，但不影响系统的处理效率。跨膜压力、膜面流速越大，通量衰减得也就越快。