钴在土壤和植物系统中的迁移转化行为及其毒性

钴是人与动植物必需的微量元素,但土壤环境中过量的钴可通过土壤-粮食/蔬菜-人与动物等途径进入人体或动植物体内,对其产生危害,因此有必要了解土壤中钴的含量,应该将钴纳入必须检测与掌控的指标。然而,我国目前对于土壤中钴的含量却没有一个明确的评价体系,致使无法有效地对土壤中钴的含量进行评价和管控,从而给土壤以及人和动植物的健康都带来一定的风险。本文通过整理近20多年的国内外文献资料,综述了钴的特点、应用、形态、含量、毒性、评估方法,指出了现行对土壤中钴污染风险评估体系中存在的问题,并提出了今后的研究方向。     

神经网络模型森林生物量遥感估测方法的研究

森林生物量的估测是全球变化研究的基础,而遥感宏观、综合、动态、快速的特点决定了基于遥感的生物量模型为森林生物量估测的发展方向,目前的遥感生物量估测方法大多基于回归分析,需要预先假设、事后检验,仅为经验性的统计模型。神经网络的分布并行处理、非线性映射、自适应学习和容错等特性,使其具有独特的信息处理和计算能力,在机制尚不清楚的高维非线性系统体现出强大优势,可以用于遥感生物量估测。文章在野外调查的基础上,尝试应用BP网络和RBF网络技术,建立广州TM遥感影像数据与森林样方生物量实测数据之间的神经网络模型,通过训练和仿真,与生物量实测数据进行比较。结果表明,在独立样地估测中,人工神经网络估测的相对误差均小于15.18%,获得了满意的效果。而RBF网络与BP网络相比,在识别精度上、稳定性、速度上,均优于BP网络,其最大相对误差不超过10.12%,平均相对误差为4.76%。可见应用神经网络方法的“黑箱”操作虽然难以归纳出指导性规律,但可以获得很高的精度。尤其RBF网络,在训练完成后,可以应用该模型进行大区域生物量估算,对于森林的规划及管理具有深远意义。     

Ag—Mn,Ag—Co和Ag—Ce复合氧化物上CO,丙酮和吡啶的催化燃烧

本文考察了Ａｎ－Ｍｎ，Ａｇ－Ｃｏ和Ａｇ－Ｃｅ复合氧化物上ＣＯ，丙酮和吡啶的催化氧化性能，结果表明，双组分Ａｇ－Ｍｎ／Ａｌ２Ｏ３和Ａｇ－Ｃｏ／Ａｌ２Ｏ３催化剂的氧化活性均高于单组分Ａｇ／Ａｌ２Ｏ３．在Ａｇ－Ｃｅ／Ａｌ２Ｏ３催化剂上，ＣＯ氧化反应的速率言程可用ｒ＝ｋＰｏ２＾ｍＰＣＯ来表示，随着催化剂中氧化铈含量的增加，对氧的反应级数明显下降。     

Use of a multi-layer column device for study on leachability of nitrate in sludge-amended soils

This paper described a multi-layer column device constructed with six cylindrical polythene tubes with installation of Rhizon soil moisture samplers (Rhizon SMS). The feasibility of using the column device to collect soil solution and percolate and to monitor leachability of nitrate in two sludge-amended soils was evaluated under glasshouse conditions. The soil moisture sampler in the device was demonstrated to be a non-destructive, simultaneous, sequential, convenient and rapid sampling tool for multiple-site porewater extraction. The device provided an in situ monitoring technique for leachability of nitrate in a soil profile following application of the anaerobically digested sewage sludge. The monitored results showed that surface soil amendment of the sewage sludge increased markedly the concentration of nitrate in the soil solutions at depths of 10-30 cm in a neutral paddy soil and at 30-50 cm in an acid red paddy soil. This amendment also largely increased nitrate in the percolates of the acid red soil. The movement and distribution patterns of nitrate in the profile were related to soil types, profile depths and experimental periods. Land application of sewage sludge may pose a risk in groundwater contamination of nitrate.     

新型甲醛被动式检气管的研制

新研制的甲醛被动式检气管是建立在气体分子扩散和化学吸收原理基础上的，检气管内的惰性担体上浸渍了对甲醛特效的希夫试剂。当管内进入甲醛气体时，即发生显色反应，检气管的显色长度的平方与甲醛浓度及采样时间的乘积成线性关系。检出下限为０．０１５ｍｇ＃Ｌ（采样５ｈ），它集采样与分析为一体，结构简单，不需动力，便于携带和操作方便，应用于检测某厂刨花板车间和制胶车间的甲醛气体，与传统的注射器采样比色分析法对比，结     

光子相关光谱（PCS）在无机高分子絮凝剂形态表征中的应用

本文运用现代先进的微粒检测手段光子相关光谱对常见的两类无机高分子絮凝剂的形态进行了表征。实验结果表明：在所测聚合氯化铁溶液中，体系呈较为单一的集中分布，由平移扩散系数计算得到平均有效直径在５－１１ｎｍ左右。在所测聚合氯化铝溶液中，主要为双峰分布，熟化后样品约为２－５ｎｍ的小颗粒与数十ｎｍ以上分布较宽的聚集体，另外，本文对光子相关光谱在形态表征中的优缺点及其它应用的可能性也作了一定的论述。     

活性炭纤维净化印刷过程产生的VOCs废气

介绍了应用局部排气的方法,收集印刷过程的挥发性有机化合物(VOCs)废气,应用活性炭纤维(ACF)吸附脱附有机废气回收净化装置,进行印刷厂VOCs废气的回收与治理,详细描述了印刷车间VOCs废气的收集与处理工艺过程及其效果.测试结果表明,应用此工艺和设备可以有效地进行印刷过程大风量的VOCs废气的回收和治理.     

2株漂白废水高效降解菌的选育

用含氯漂白废水驯化城市污水处理厂的好氧污泥 ,从中分离出两株高效去除有机氯的菌 ,并对其适应条件进行了研究。结果表明 ,当pH为 7.0、废水浓度为 5 0 %、加入 0 .4g/L葡萄糖、2mL菌液时 ,处理效果较好 ,有机氯的去除率最高可达 74 .8%。     

Changes in soil microbial biomass and Zn extractability over time following zn addition to a paddy soil

A laboratory incubation study was conducted using a paddy soil spiked with two quantities of Zn as soluble Zn(NO3)2 and unamended controls. Three single extractants (1 M ammonium acetate (pH 7.0), 0.43 M acetic acid and 0.05 M EDTA) were used to assess the bioavailability of Zn. Biological community assessments were made microbial biomass (chloroform fumigation), soil basal respiration and dehydrogenase activity. During the 84-day period of the experiment, addition of Zn at both 500 and 1,000 mg kg(-1) had little detectable effect on soil pH. The concentration of NH4OAc-extractable Zn decreased rapidly within the initial six weeks. The concentration of HOAc-extractable Zn showed no decrease during 84 days incubation. EDTA-extractable Zn was greater than NH4OAc- and HOAc-extractable fractions, and showed a similar trend to NH4OAc-extractable after incubation. Microbial biomass, soil basal respiration and dehydrogenase activity all decreased over time during 84 days incubation. Addition of Zn resulted in a significant increase in specific respiration (qCO2). Microbial biomass and dehydrogenase activity did not appear to be influenced by added Zn, probably due to the strong buffering capacity of the soil. The Zn extracted by EDTA, HOAc and NH4OAc showed close relationships with each other (p < 0.001). Zinc extracted by 0.05 M EDTA and NH4OAc were highly correlated with soil basal respiration and specific respiration rate (p < 0.01). The results suggest that NH4OAc-extractable Zn combined with soil specific respiration could be used as parameters for risk assessment.     

Fungal degradation of metsulfuron-methyl in pure cultures and soil

A fungal strain capable of utilizing metsulfuron-methyl as sole carbon and energy sources was isolated from a metsulfuron-methyl treated soil. The degradation characteristics of metsulfuron-methyl by this fungal strain were investigated in liquid culture and soil. More than 79% of metsulfuron-methyl at concentrations of 0.10 mgl(-1), 1.0 mgl(-1) and 10.0 mgl(-1) in pure culture was degraded by strain MD after incubation for 7 days, whereas only 5.6%, 8.6% and 13.1% of metsulfuron-methyl were degraded at levels of 0.10 mgl(-1), 1.0mgl(-1) and 10.0 mgl(-1) in the controls, respectively. The incorporation of strain MD into soil was found to substantially increase the degradation of metsulfuron-methyl. Degradation was 7.5 and 3.8 times faster in strain MD amended soils than in sterilized and fresh soils. The results show that addition of the isolated strain MD enhances degradation of metsulfuron-methyl in water and soil.