粉煤灰对垃圾填埋场黄土垫层的改性试验

通过击实、渗透试验得到粉煤灰改性-黄土的最佳配比为10%。对压实黄土和压实粉煤灰改性-黄土,分别用清水和渗滤液进行室内渗透试验,结果表明:渗滤液在压实粉煤灰改性黄土中的渗透系数≤1.0×10-7cm/s,在压实黄土中的渗透系数≤1.0×10-5cm/s,前者可作为填埋场防渗垫层,后者可作为填埋场防渗保护垫层。对COD、NH3-N的去除效果前者优于后者。     

碱消解-P&T-GC-AFS法同时测定土壤中的甲基汞和乙基汞研究

建立了碱消解-吹扫捕集-气相色谱-原子荧光光谱法(P&T-GC-AFS)同时测定土壤中甲基汞和乙基汞的分析方法.样品在90℃条件下经氢氧化钾/甲醇消解2.5 h,调节pH为5.40,并丙基化衍生后,采用P&T-GC-AFS法测定.方法对甲基汞、乙基汞的线性相关系数分别为0.999 7、0.999 6,检出限分别为0.26、0.41 ng·g -1.在不同质量浓度水平上进行加标回收率实验,甲基汞、乙基汞的回收率分别为90.5%~93.3%、86.5%~89.6%.该方法样品前处理简单、检出限低,适合批量测定土壤中甲基汞和乙基汞.     

水系沉积物重金属分析前处理方法

建立了水系沉积物中6种重金属分析的前处理方法,研究了样品粒径、消解前处理对测定结果的影响,对方法适用性作出评价,并对实际样品进行测定。结果表明:通过Hg元素含量的测定,粒径为0.147 mm的沉积物粒径可满足分析要求;采用微波-硝酸-盐酸-氢氟酸消解、ICP-MS法,对5种不同类型沉积物标准样品的6种重金属的测定结果显示,该方法精密度好、准确度高。利用建立的方法测定广西某河流湖库沉积物样品,6种元素测定结果 RSD为1.57%~11.1%,加标回收率大于74.4%。     

HPLC荧光检测大气环境中苯并(a)芘及分布规律的研究

苯并(a)是强致癌物,被认为是环境中有多环芳烃类化合物存在的指标,本文使用美国光谱物理公司的高效波相色谱仪,以甲醇/水为流动相,采用spheri-5,RP-18柱及FL2000荧光检测器完成了大气颗粒物中BaP的测定,其加标回收率为91％,变异系数<5％,本方法最小检出限为0.02ng。同时,以马鞍山市大气环境中苯并(a)芘监测数据为第一手资料,对苯并(a)芘的分布状况、规律、危害作了研究。     

“十一五”期间大凌河朝阳段水环境质量变化趋势研究

通过分析"十一五"期间大凌河朝阳段环境质量变化趋势,发现:氨氮浓度呈整体上升趋势,化学需氧量浓度呈整体下降趋势;氨氮从V类水质降低到中劣V类水质标准,化学需氧量从劣V类水质升高到中IV类水质标准。"十一五"期间大凌河朝阳段水环境质量的变化原因为:城市污水处理厂对氨氮去除率不高。基于此,提出了"十二五"期间大凌河朝阳段可将调整产业结构、发展绿色经济、实施污染治理三大工程作为水环境污染防治对策。     

城市生态系统健康评价新模型及应用——以天津市为例

从城市生态系统的活力、组织结构、恢复力、生态系统服务功能及人群健康5个方面建立了城市生态系统健康评价的指标体系,并针对目前现有的城市生态系统健康评价模型的不足,以最大流原理为基础,以自组织特征映射神经网络(SOM)为算法实现手段,从复杂系统结构演化的角度提出了一个新的城市生态系统健康评价模型.进而使用该模型对2001-2009年天津市生态系统健康进行评价.结果表明,天津市2001-2007年城市生态系统处于亚健康状况,2008、2009年处于较健康的状况,并得出天津市生态系统健康状况处于逐年增长的趋势的判定.由于该模型从一定程度上体现了城市生态系统健康的演化动力学机理和城市生态系统时空演变特性,因此,不仅在评价上有较大的优越性,在城市生态系统健康发展变化状态的预测上也具有潜力.     

Effects of oxygen on the release and distribution of phosphorus in the sediments under the light condition

Effects of oxygen on the release and distribution of phosphorus (P) in the sediments in the presence of light were investigated, using sediment cores and overlying water from Lake Taihu, in China. The results show that P can be released from sediments to the overlying water in both anoxic and aerobic conditions. But more P was released in the anoxic condition. The transformation of P between various fractions in the sediments was observed during the release experiments. Concentrations of Ca-bound P and organic P in the sediments decreased in both conditions, but Fe/Al-bound P increased in the aerobic condition. The decrease of total P and P fractions in the sediments is consistent with the accumulative increase in quantity (AIQ) of total P (TP) in the overlying water, but is contrary with the AIQ of dissolved inorganic P. This is due to the uptake of algae by the dissolved inorganic P. Total nitrogen in the sediments in the anoxic condition was lower than that in the aerobic condition, and pH in the overlying water increased in the anoxic condition.     

低碳生态城市发展水平评价的新模型及应用——以天津市为例

把低碳生态城市考虑成一个包含众多相互耦合的组元的非线性复杂系统,建立起一个评价低碳生态城市发展水平的最大信息熵(MIE)模型,计算了ξ参量及系统演化动力学方程,其中,ξ参量是低碳生态城市系统组元间相互耦合形成的结构模式,表征系统发展水平的高低.同时,对2007—2011年间天津市低碳生态城市发展水平进行了评价.结果表明,2007—2011年天津低碳生态城市发展水平逐渐提高,而以ξ值来度量的环比增长速度在2008年达到最大值6.96%.ξ值各分量的雷达图表明,交通系统的完善、第三产业的发展和固定资产投资规模的增大是5年间这一低碳生态城市系统发展的主要推动因素.ξ-xi的拟合结果显示,指标的实际值与理论预测值间的误差比较小,证实了MIE模型可以用于低碳生态城市发展水平的预测;与灰色预测法的比较表明,MIE模型可以更准确地对低碳生态城市的发展水平进行评价.本文最后讨论了MIE模型在低碳生态城市发展水平评价上的特点及优势.     

Effects of organisms on the release of phosphorus at the interface between sediment and water.

Organisms at the interface between sediment and water play a significant role in the cycling of phosphorus. This study reports experimental results of the influence of organisms on phosphorus release. Results show that benthic organisms controlled the low level of phosphate in overlying water with light. The maximum phosphorus release rate can reach 7.31 mg m(-2) d(-1) without organisms, nearly twice that in a similar system with organisms. However, significant decreases in the concentrations of sodium-hydroxide-extractable phosphorus and hydrochloric-acid-extractable phosphorus were observed in the experimental system with organisms, while no significant changes were observed without organisms. In addition, the dissolved oxygen concentration in the system was higher with organisms than without organisms with light. This study is significant to the understanding of phosphorus cycling at the interface between sediment and water in lakes.     

Effects of organisms on the release of phosphorus at the interface between sediment and water.

Organisms at the interface between sediment and water play a significant role in the cycling of phosphorus. This study reports experimental results of the influence of organisms on phosphorus release. Results show that benthic organisms controlled the low level of phosphate in overlying water with light. The maximum phosphorus release rate can reach 7.31 mg m(-2) d(-1) without organisms, nearly twice that in a similar system with organisms. However, significant decreases in the concentrations of sodium-hydroxide-extractable phosphorus and hydrochloric-acid-extractable phosphorus were observed in the experimental system with organisms, while no significant changes were observed without organisms. In addition, the dissolved oxygen concentration in the system was higher with organisms than without organisms with light. This study is significant to the understanding of phosphorus cycling at the interface between sediment and water in lakes.