广西涠洲岛沉凝灰岩土壤粘粒矿物的研究

用X射线衍射分析和电子显微镜分析,对涠洲岛沉凝灰岩母质发育土壤的两个典型剖面八个土样的粘粒矿物进行分析研究。结果表明,离火山口距离不同的两个剖面土壤粘粒矿物组成不同,1号剖面以2:1型粘粒矿物为主,2号剖面则以1:1型粘粒矿物为主;结合其它分析结果,讨论了两个剖面土壤粘粒矿物组成不同的原因、对土壤有关特性的影响及其与土壤形成和分类的关系。     

GIS技术在区域土壤有机碳储量估算方面的应用--以柴达木盆地为例

目前在估算土壤有机碳储量方面的方法较多,并且都有其各自的特点所在。地理信息系统(GIS)技术作为当今一种在地学统计分析方面具有强大空间分析功能的计算机应用技术,在地学及相关研究领域得到了广泛的应用。文章首次尝试了利用该技术估算柴达木盆地土壤有机碳储量,该方法与其它计算方法相比,有简单、易操作、可视性好等优点。经计算,柴达木盆地的土壤有机碳储量约为62754.442 t,土壤平均碳面密度为6.105 kgm-2。     

水生细菌对原生动物的反捕食对策

The research progress in the defense strategies of aquatic bacteria to protozoa was reviewed in this paper, Aquatic bacteria can reduce or avoid grazing mortality from protozoa through changing size or shape, reducing cell surface hydrophobieity, reducing mobility or searching refuges. It is the main trends of the field in the future to study the coevolution mode of aquatic bacteria and protozoa. Ref 47     

铁催化聚丙烯腈脱氮的研究

应用热天平研究了载铁聚丙烯腈的脱氮碳化行为，负载铁对ＰＡＮ的稳定化和脱氮碳化均具有显著的催化作用，并在５８０－７６０℃范围内明显增加了Ｎ２形成速率。ＸＰＳ和ＸＲＤ对碳化过程中铁和氮化学形态变化的研究结果表明，铁催化反应机理可能是负载铁与吡啶氮作用形成中间体铁氮化物，后者进而分解释放出Ｎ２。     

单甲脒农药对模型池塘生态系统藻类群落结构的影响

在１．５－５０．０ｍｇ／Ｌ的浓度范围内，单甲脒农药对模型池塘生态系统中的浮游植物群落结构有明显影响。尤其在加药的头４ｄ内，藻类种类、数量、多样性指数、种类数比及增长率明显下降，优势比显著上升，敏感种及清洁种减少甚至消失，高浓度（５０．０ｍｇ／Ｌ）的单甲脒在２ｄ内可把藻类全部杀灭。随试验时间的延长，药物不断降解，６ｄ后藻类种类、数量、多样性指数又不断回升。随加药次数的增多，药物对藻类抑制作用明显减弱，藻类的种类、数量、多样性指数等指标不断上升，尤其是藻类数量增加明显，试验后期，藻类数量高低主要受Ｎ、Ｐ浓度大小的影响。     

活性污泥对重金属离子混合物的生物吸附

采用城市污水处理厂产生的活性污泥研究了影响污泥吸附Zn^2 ，Cu^2 和Cd^2 三种重金属离子的主要因素，在实验条件下，温度对污泥吸附重金属的影响并不显著，而体系Ph值和吸附时间等的影响较为重要，活性污泥对Cu^2 的吸附符合Langmuir模型，Zn^2 则与Freundlich模型的符合程度优于Langmuir模型，Cu^2 的吸附与两个模型的符合程度一致，另外，活性污泥对Cu^2 离子的吸附性能明显高于其他离子，但在实验中未发现不同金属离子之间存在明显吸附抑制或促进。     

Bioleaching of spent Ni-Cd batteries and phylogenetic analysis of an acidophilic strain in acidified sludge

Biohydrometallurgy is a novel method to recycle discarded batteries, in which sewage sludge is used as microorganisms and culture due to the presence of indigenous Thiobacilli. A two-step continuous flow leaching system consisting of an acidifying reactor and a leaching reactor was introduced to achieve the bioleaching of spent nickel-cadmium (Ni-Cd) batteries. The acid supernatant produced in the acidifying reactor by the microorganisms with ferrous ions as the substrate was conducted into the leaching reactor to dissolve electrode materials. The efficiency of a batch treatment of batteries was examined. The results showed that the complete dissolution of two AA-sized Ni-Cd batteries with 0.6 L/d acid supernatant took about 30, 20, and 35 days for Ni, Cd, and Co, respectively. But the dissolution ability of the three metals was different. Cd and Co can be leached mostly for pH below 4.0 while the complete dissolution of Ni can be achieved for pH below 2.5. Meanwhile, a strain (named Thiooxidans. WL) accounting for the reduction of pH in the acidified sludge was isolated and sequenced. It was identified to be 100% similar to Acidithiobacillus ferrooxidans strain Tf-49 based on 16S rDNA sequence analysis. The relevant phylogenetic tree constructed indicates that the strain should be classified into genus Acidithiobacillus ferrooxidans.     

向海湿地河道上下游土壤重金属污染程度分析

以向海湿地河道上、下游土壤沉积物为研究对象，以Al元素作为标准化元素，通过对重金属元素富集因子的分析，研究了Cu、Ni、Mn、Fe、Ba、Cr等6种重金属元素的人为污染状况及分级。结果表明，该区土壤沉积物中重金属元素均受到不同程度的人为污染影响，部分层面Ni、Ba等重金属元素污染程度达到显著水平，造成这种现象的主要原因是富含重金属的霍林河上游矿源物质的沉积及人类对湿地开发活动的历史变迁过程；此外，径流淹没频率不同造成了两断面土壤沉积类型和沉积效果的不同，使得受水文影响较大的上游断面的人为污染程度大于受影响较小的下游断面，说明向海湿地对人为污染具有一定的缓冲能力，或向海湿地具有较强的净化和过滤功能。     

Population dynamics and production of the planktonic copepods in a eutrophic inlet of the Inland Sea of Japan. IV. Pseudodiaptomus marinus, the egg-carrying calanoid

Population dynamics and production of the egg-carrying calanoid copepod Pseudodiaptomus marinus were studied for a year in Fukuyama Harbor, a eutrophic inlet of the Inland Sea of Japan. This species was perennial, with a large numerical peak in June and small peaks in September/October and November/December. During the study period, at least 11 generations could be detected. For each generation, the stage-specific survival from egg to Copepodite Stage (C) V was determined; it was very high during early life stages (egg to NIII), and gradually decreased beyond. On average, 94% of eggs recruited into NIII, which is strongly contrasted with very high (>ca. 90%) mortality during the corresponding stages for free-spawning copepods, i.e. Acartia omorii, Centropages abdominalis and Paracalans sp. This demonstrates that the egg-carrying strategy has a great advantage to reduce mortality in egg stage. The biomass of this species showed marked seasonal variations largely in parallel with numerical abundance. The instantaneous somatic growth rate increased linearly with temperature. The population production rate was estimated as the sum of somatic growth of larval stages and egg production of adult females; the annual integration was 51.0 mg C m⁻³ yr⁻¹ or 0.38 g C m⁻² yr⁻¹. Received: 11 November 1996 / Accepted: 7 December 1996     

Single and joint effects of acetochlor and urea on earthworm Esisenia foelide populations in phaiozem

Much attention is paid to soil health and environmental safety. Earthworms are an important indicator of soil ecosystem health and safety. Ecological toxicity of acetochlor and excessive urea, in both their single and joint effects, on earthworm Esisenia foelide was thus studied using the soil-culture method. Acetochlor had an enhanced toxicity from low concentration to high concentration. The mortality of earthworms after a 6-day exposure was changed from 0 to 86.7%, and the weight change rate ranged from 7.86 to -30.43%, when the concentration of acetochlor was increased from 164 to 730 mg kg(-1). Urea expressed its positive and beneficial effects on earthworms when its concentration was lower than 500 mg kg(-1). Strongly toxic effects took place when the concentration of urea was higher than 1000 mg kg(-1). The mortality of earthworms exposed to urea reached 100% when its concentration was more than 1500 mg kg(-1). When the concentration of urea was lower than 500 mg kg(-1), there were antagonistic effects between the two agrochemicals on earthworms; when the concentration of urea was higher than 500 mg kg(-1), joint toxic effects of acetochlor and excessive urea on earthworms were synergic. In any case, excessive urea application is very harmful to the health of soil ecosystems.