Radioactive Isotopes of Strontium,Caesium and Plutonium in Sediments of the Northern Adriatic Sea

Changes in nitrification rates of an acid grassland soil with and without air drying have been monitored over 9 days, after first flushing native nitrate from the soils with deionised water. The results confirmed that full re-establishment of nitrification after air drying takes several days, supporting the hypothesis that any immediate first flush of nitrate from air-dried soils originates from cell lysis or flushing of ‘stored’ nitrate. Ammonium spiking confirmed that nitrification was not ammonium substrate limited. It was also found that ammonium accumulates in the soil during the drying process, providing a substrate pool once the population of nitrifiers has re-established. Over the first week of incubation, nitrate immobilisation was less conspicuous in the soil that had been rewetted after air drying compared with the incubated field moist soil.     

Applications of Satellite Remote Sensing to Marine Pollution Studies

There are two approaches in the application of satellite sensors to marine pollution studies. Satellite sensors are used to observe and characterize ocean pollutants such as industrial wastes and oil. in addition, satellite observations provide information useful in illuminating processes such as eutrophi-cation or air-sea exchange of CO₂, that are important in determining the distribution and fate of pollutants.

Satellite technology is an important tool in monitoring and studying ocean pollution. Visible sensors have been used to observe and characterize sewage sludge and industrial wastes dumped at sea. Oil slicks have been observed with Landsat, AVHRR and SAR imagery. Besides directly detecting pollutants, satellite sensors are useful for analyzing ocean processes that are influential in the fate of pollutants. These processes include eutrophication of coastal waters and the distribution of suspended matter. the fate of excess CO₂ can be addressed using scatterometer-derived estimates of wind speeds to determine the CO₂ exchange coefficient at the sea surface on a global scale.     

内循环三相生物流化床处理味精废水

利用混合异养硝化-好氧反硝化菌群在内循环三相流化床内处理实际味精废水,以火山岩为载体,考察了反应器的启动和驯化,分析了污染物进水浓度变化对处理效果影响和同步硝化反硝化效果。结果显示,经过10 d的间歇闷曝,微生物附着在载体表面,挂膜成功;经驯化可处理较高浓度的味精废水并具有较强耐冲击能力;同步好氧硝化反硝化效果良好。     

垃圾渗滤液对斑马鱼的毒性及抗氧化酶活性的影响

在室内模拟条件下,以斑马鱼（Daniorerio）为受试动物,探讨生活垃圾渗滤液对斑马鱼的急性毒性及对其鱼鳃、肝脏中的过氧化物歧化酶（SOD）、还原型谷胱甘肽（GSI-I）及Na＋,K＋-ATP酶等3种酶的影响。结果表明,垃圾渗滤液对斑马鱼的96hLC50为13．2％。垃圾渗滤液对斑马鱼的急性毒性相对较高,斑马鱼对垃圾渗滤液毒性的敏感性强。慢性毒性测试结果显示,垃圾渗滤液对斑马鱼肝脏中SOD活性和GSH质量分数的诱导作用明显,对Na＋,K＋-ATP酶活性影响并不明显;垃圾渗滤液对斑马鱼鱼鳃中SOD活性影响显著（P〈0．05）。除Na＋,K＋-ATP酶外,斑马鱼的抗氧化防御相关生物标志物对渗滤液染毒胁迫具有相对较高的敏感性,SOD和GSH均可用作垃圾渗滤液慢性胁迫的有效生物标志物。     

垃圾填埋场周边枝树光合生理特性研究

为了解垃圾填埋场环境下植物的光合适应性,利用LI-6400便携式光合测定仪,以呼马山森林公园为对照,对位于昆明市东郊垃圾填埋场和对照区的直杆桉Eucalyptusmaideni进行了光响应与光合日进程的测定。结果表明：填埋场直杆桉的净光合速率随光强的增加先增加后稍有下降并趋于稳定,光抑制不明显;对照的净光合速率随光强的增加先增加后缓慢下降;在相同光照强度下,填埋场直杆桉的净光合速率、蒸腾速率始终高于呼马山对照的,说明直杆桉可通过提高自身的光合能力和蒸腾速率来适应填埋场的特定环境。胞间CO2浓度随光强的增加先下降后上升,与净光合速率大体呈相反变化;蒸腾速率随光强变化的趋势与气孔导度变化相一致。另外,填埋场直杆桉净光合速率日变化呈单峰曲线,无明显“午休”现象,其变化趋势与蒸腾速率、气孔导度的大体相同。对照的净光合速率、气孔导度、蒸腾速率与填埋场的变化趋势相似,但变化幅度较少。在自然条件下,填埋场直杆桉的净光合速率和蒸腾速率仍明显高于呼马山对照的。     

基于反赋权与MBCT-SR多维云模型算法岩爆预测研究

基于岩爆事故的模糊性与随机性特征,为解决在当前岩爆烈度等级预测研究中,通过正向云发生器经验式计算多维云模型特征值进而导致预测结果主观性较强的问题.本文选取应力比Ts=σθ/σt、岩石脆性指数B=σc/σt以及弹性应变储能指数Wet作为评价指标,结合机器学习理论,采用多维逆向MBCT-SR云发生器算法对岩爆等级进行预测,...     

超滤应用于中水系统反渗透浓水回用的试验研究

河北某电厂拟将中水系统中反渗透浓水采用超滤处理进行回用,研究了浓水水质以及pH值对超滤处理效果的影响。结果表明,pH值在5.5左右时超滤处理效果最好,对该浓水中的有机物和硅的去除效果明显。     

氯胺消毒管网“三氮”与总氯变化的预测模型

为探讨氯胺消毒供水管网的水质问题,建立了一种试验规模的氯胺消毒供水管网水质模拟系统。基于质量守恒原理和双Monod方程建立了该系统的硝化与氯胺衰减动力学耦合模型,并通过试验对该模型进行了验证。模型中的部分参数采用非线性多项式回归方法进行估计。应用该模型确定了活性氨氧化菌(AOB)和亚硝酸盐氧化菌(NOB)的数量。该模型对管网模拟系统内氨氮、硝酸盐氮与总氯的预测值与实测值基本一致,但对亚硝酸盐氮的预测值与实测值存在较大偏差。     

垃圾渗滤液生物处理系统BP人工神经网络模型

垃圾渗滤液成分复杂,变化范围大．对其调试及长期持续良好运行存在较大困难。本文针对武汉市二妃山垃圾渗滤液的调试运行数据,利用人工神经网络原理,建立BP人工神经网络垃圾渗滤液生物处理模型来预测处理效果．确定最优反应条件。实验结果显示网络具有良好的收敛特性,模型具有工程实用价值。     

简易垃圾填埋场存在问题及治理技术探讨

分析了大冶有色金属公司简易垃圾场存在垃圾堆体不稳、二次污染的问题,探讨了控制污染源、防止二次污染及堆体倒塌的治理技术。