The Adsorption of Lead and Copper from Aqueous Solution on Modified Peat–Resin Particles

Raw peat was modified with sulfuric acid, then mixed modified with resin to prepare the modified peat–resin particles. Using the batch experimental systems, the removal of heavy metals (copper and lead) on the modified peat–resin particles was investigated. The data of the adsorption isotherm could be fitted by the Langmuir equation well. The adsorption rate of heavy metals on modified peat–resin particles was very swift. The removal processes of heavy metals on modified peat–resin particles could be well described by pseudo-second order model. The adsorption rate of lead was affected by the initial heavy metal concentration, initial pH, particle size, agitation speed and particle mass. In the adsorption of heavy metals (lead and copper) on the modified peat–resin particles, ion exchange was the major reaction mechanism. Desorption data showed that the lead adsorbed by modified peat–resin particle could be desorbed by 0.5 N or 1.0 N HNO₃. The desorption rate was swift. The experiments indicated that the modified peat–resin particles have great potential for the removal of heavy metals from wastewater.     

应用油松针叶监测大气二氧化硫污染

承德市油松针叶中硫与大气ＳＯ２浓度之间存在着很显著的相关性（ｒ＝０．７８４１，Ｐ＜０．０１），利用这一相关性对承德市区４２个采样点大气ＳＯ２污染状况进行了生物监测，并绘制了城市大气ＳＯ２污染分布图，基本符合承德市大气ＳＯ２分布规律。     

论自然资源费制度

在国家控制自然资源和重要自然资源国家所有的模式下,原生态的自然资源主要由国家供给和管理,而通过法律构建自然资源费制度是自然资源有偿使用和有偿管理,并进行自然资源更新、培育的有效途径。明确自然资源费的涵义和分类,依据公共物品和外部不经济内部化理论,并结合社会转型过程的法律背景确立自然资源费制度的内容是构建这一制度的关键。     

Biologically active secondary metabolites in white clover (Trifolium repens L.) – a review focusing on contents in the plant, plant–pest interactions and transformation

Summary.  To exploit biologically active compounds from white clover (Trifolium repens L.) for suppressing weeds and soil-borne diseases, either as isolated products (biopesticides) or through cultivars with enhanced production of these compounds, the biologically active compounds must be identified, plant content measured, and their fate in soil known. The present review summarizes the published knowledge needed for such exploitation; providing essential information on structure and concentration of flavonols, flavones, condensed tannins, isoflavones, isoflavanones, pterocarpans, coumestans, cyanogenic glucosides, and saponins in healthy and stressed white clover plants. Various stresses and particular cultivars affect the concentrations of several of the compounds. Information on biological effects and the degradation/transformation of these compounds in plants or by microorganisms is available. There is no information on the degradation pathway in soil, the mechanisms of exudation and leaching of compounds from plants, and soil sorption properties of the compounds. The clover soil fatigue problem is increasing in grasslands and causes problems especially in organic farming. Research efforts focused on biological elements of clover soil fatigue have not explained it, and the influence of secondary metabolites has not been investigated. There are few investigations into the interaction between beneficial fungi/fungal-diseases and the occurrence of biologically active secondary metabolites in white clover plants. Such studies are critical to better understand beneficial fungi and pathogens.     

深水型湖泊底泥NH4+-N释放的环境因子影响实验研究

通过对深水型人工湖泊(以福州市山仔水库为例)底泥NH4 -N释放特性进行实验研究,该实验在厌氧状态下进行,主要是以氨态氮溶出为主,这是一个物理过程,是由于分子的扩散造成的,分析了环境因子对底泥NH4 -N释放特性的影响及其原因.得出了温度、上覆水本身NH4 -N浓度和底泥粒径对底泥NH4 -N释放影响的动力曲线.同时说明了湖泊底泥NH4 -N释放对湖泊水质存在着潜在的危险性.为城市深水湖泊底泥疏浚和富营养化治理提供依据.     

盐分对粉壤土氮转化的影响

采用室内恒温通气培养法,以北京地区耕作层典型粉壤土为对象,研究盐分对土壤氮素矿化和硝化的影响.实验设置了4个不同盐分〔以ρ（NaCl）计,分别为20,30,50和80 mg/L〕处理和对照处理,并在硝化实验的土壤中加入一定量的（NH₄）₂SO₄,分别在30 ℃恒温培养箱中进行为期105 d（矿化）和49 d（硝化）的培养实验.结果表明:在初期的培养中,低盐分有利于土壤氮素转化,ρ（NaCl）为20 mg/L的处理分别比对照处理的累积矿化量和累积硝化量多18.21%和1.87%;而在长期培养过程中,高盐分不利于土壤氮素转化,且ρ（NaCl）越高抑制越明显,其对土壤氮素矿化和硝化的抑制率达到67.92%和62.58%;土壤矿化势和硝化势随w（NaCl）分别呈指数递减,矿化速率常数和硝化速率常数与土壤中w（NaCl）为二次函数关系.      

几种厌氧颗粒污泥的性质分析

颗粒污泥是存在于厌氧反应器中具有自我平衡的微生态系统。颗粒污泥的形成有利于有机物的降解,增强反应器的运行稳定性。本文通过对几种工业化运行的厌氧反应器中生长的颗粒污泥的分析,比较了在各种运行条件下颗料污泥的特征,并阐述了颗粒污泥的形成、生长与各种运行条件的关系。     

Acute effects of low-dose cypermethrin on male rat cells

Effects of synthetic pyrethroid insecticide α-cypermethrin were investigated following intradermal dose (5–50 mM) of cypermethrin to male albino Wistar rats. Glucose, protein, cholesterol, triglycerides, urea, uric acid, creatinine, hemoglobin, blood RBC, and WBC content were determined 6 h after pesticide administration. Biochemical parameters and blood cell count changed significantly in treated rats at all doses. Low-dose cypermethrin affected early biochemical changes in rats.     

渗滤液灌溉土壤N2O释放及氨挥发的研究

选用2种供试土壤（S1和S2）,通过培养试验研究了渗滤液投加土壤后N₂O释放、氨挥发及矿物氮的转化,并讨论了土壤理化性质对上述过程的影响.土壤pH值较大程度地决定了氨的挥发,仅投加渗滤液的碱性土S1在培养期的前5 d内测到氨挥发,通过氨挥发共损失了约3.0‰的渗滤液氮.投加同等含量的渗滤液后,不同土壤可导致N₂O释放量近20倍的差异(p<0.01).土壤含水率（WFPS）影响了土壤中硝酸盐氮的生成速率,从而制约了N₂O释放通量的高低.与WFPS为46%时相比,投加蒸馏水的土壤S1、投加渗滤液的土壤S1和土壤S2在WFPS为70%的条件下N₂O的释放通量均值分别提高了6.5 (p>0.05)、 1.8(p>0.05)和2.2倍(p<0.05).渗滤液投加土壤在10 d培养期内,土壤S1和S2因N₂O释放分别损失了41.1‰和2.3‰的渗滤液氮.为此,控制灌溉土壤的含水率(<70% WFPS),并选用酸性土壤可有效地控制渗滤液灌溉下N₂O的释放和氨挥发.     

星云湖、杞麓湖磷污染来源比较

通过对星云湖、杞麓湖水体磷含量变化情况、流域产业结构和磷入湖途径的比较分析，认为近年来星云湖水体磷含量水平的大幅提高，使星云湖水质由Ⅲ类在大约5a的时间里下降为Ⅴ类、劣Ⅴ类，与星云湖流域及周边磷化工产业的快速发展息息相关。而杞麓湖由于流域内无磷矿资源也没有大的磷化工产业，其磷含量水平得于稳定。