蛭石对汞的吸附性能研究

研究了以蛭石作为吸附剂对汞的吸附作用，并探讨了蛭石的改性和添加絮凝剂的联合吸附情况。实验结果表明，蛭石对汞具有较强的吸附作用，吸附速度快；蛭石经CTMAB改性后对汞的吸附能力显著提高；蛭石与絮凝剂之间存在协同作用，联合处理溶液中痕量汞的效果好，用吸附絮凝法处理含汞废水有较高的应用价值。     

脉冲电晕法治理甲苯废气实验研究

有机废气的污染日益受到重视,现有的控制技术尚不完善。采用脉冲电晕法对去除甲苯模拟废气进行了实验研究,考察了反应器结构、脉冲电压峰值、气体浓度、停留时间和水汽含量等不同因素对去除率的影响。实验结果表明本法能达到较好的去除效果,在线 筒式反应器的最高去除率为35％,在线 板式反应器的最高去除率达81％,反应后的最终产物为CO、CO₂和H₂O。     

气候变化背景下“气候产量”计算方法的探讨

气候变化对于粮食安全的影响已成为全球变化研究的热点问题之一。在研究过去几十年尺度上的气候变化对粮食产量影响的程度时,常规的研究方法是利用实际产量的数据拟合出以时间为变量的趋势产量,实际产量与趋势产量的差值即为气候产量。但这种方法在评估气候变暖对粮食产量的影响时存在一定缺陷。在常规算法的基础上,论文提出一种改进算法,即通过选取基准时段,建立反映气候要素与作物单产关系的函数表达式,来估计非基准时段内的气候产量,这种方法主要适用于气候要素存在趋势性变化的时段。以黑龙江省为例,将改进算法和常规算法进行比较,结果显示应用改进算法得到的气候产量更能真实地反映气候变暖对水稻产量的影响。     

Determination of buffering capacity of total suspended particle and its source apportionment using the chemical mass balance approach

The samples of total suspended particle (TSP) from sources and TSP in the ambient atmosphere were collected in 2006 at Tianjin, People's Republic of China and analyzed for 16 chemical elements, two water-soluble ions, total carbon, and organic carbon. On the basis of the chemical mass balance (CMB) model, the contributions of different TSP sources to the ambient TSP were identified. The results showed that resuspended dust has the biggest contributions to the concentration of ambient TSP. The buffering capacity of each TSP source was also determined by an analytical chemistry method, and the result showed that the constructive dust (the dust emitted from construction work) had the strongest buffering capacity among the measured sources, whereas the coal combustion dust had the weakest buffering capacity. A calculation formula of the source of buffering capacity of ambient TSP was developed based on the result of TSP source apportionment and the identification of the buffering capacity of each TSP source in this study. The results of the source apportionment of the buffering capacity of ambient TSP indicated that open sources (including soil dust, resuspended dust, and constructive dust) were the dominant sources of the buffering capacity of the ambient TSP. Acid rain pollution in cities in Northern China might become serious with a decrease of open source pollution without reducing acidic sources. More efforts must be made to evaluate this potential risk, and countermeasures should be proposed as early as possible.     

ABR-生物滴滤池组合工艺处理农村生活污水

采用ABR-生物滴滤池组合工艺,研究在水力停留时间为3 d、滴滤池水力负荷为5 m3/（m2·d）的条件下,组合工艺对生活污水中主要污染物的去除效果、滴滤池内部污染物浓度变化和微生物的沿程分布规律。实验结果表明,组合工艺对COD、TN、NH＋4-N和TP的平均去除率分别可达73%、32%、58%和30%;滴滤池内各层污染物浓度除TP在中层略有升高外,其余均沿程逐渐降低。滴滤池底层对各种污染物的去除能力均较强,原因是果壳活性炭填料较强的截留吸附能力以及底层微生物优势菌属较好的降解作用。总氮的去除依靠滴滤池内填料的物理化学作用和微生物同步硝化反硝化作用,其中微生物作用约占60%,成为脱氮的主要途径。     

双频超声/臭氧联用处理硝基苯类制药废水研究

采用臭氧单独氧化、单频超声协同臭氧、双频超声协同臭氧氧化处理硝基苯类制药废水,考察了废水初始pH值、臭氧通入量、超声波频率及功率等因素对处理效果的影响。优化出双频超声协同臭氧处理硝基苯制药废水的最佳处理条件,经处理后的水质能达到《污水综合排放标准》(GB8978-1996)的一级排放标准.     

Top-down法计算中国五氯酚钠消费分布

为履行<关于持久性有机污染物(POPs)的斯德哥尔摩公约>,中国将逐渐淘汰POPs的生产和使用,环境介质中POPs浓度监测和处置是履约工作的重要部分,而其消费分布的研究可以为监测和模型计算找出重点区域.采用Top-down法,根据当年全国的五氯酚钠消费,以药物灭螺面积、钉螺面积、血吸虫病流行村数等为替代数据,计算了各省份的五氯酚钠消费分布,并进一步计算出省内各市级地区的五氯酚钠消费分布.从2003年的计算结果来看,五氯酚钠消费最大的是湖北省和湖南省,两省五氯酚钠消费占到全国总消费的72.62%.最主要的地区是湖北省荆州市和湖南省岳阳市、常德市、益阳市,分别占全国总消费的15.25%、12.78%、11.72%、9.89%,总和占到全国总消费的49.64%,上述地区将成为今后研究和监测的重点区域.     

沈阳城市可持续发展水平的生态足迹分析

城市地域的可持续发展必须以生态的可持续发展为前提,而生态足迹计算模型可以通过比较人类对生态环境的影响程度与区域生态承栽力之间的平衡程度来衡量的生态可持续发展状态。本文在介绍生态足迹的理论和计算模型的基础之上,对沈阳市2002年的生态可持续发展状态进行了实例计算和分析,结果表明沈阳市2002年的人均生态赤字为1．21hm^2,其城市生态处于非可持续发展状态,城市发展正以消耗自身生态资源和转移生态压力作为代价。     

Ti-Ce系列催化剂上乙酸的催化湿式氧化反应

采用Ti-Ce系列湿式氧化催化剂,研究模型反应物乙酸在催化湿式氧化反应中的动力学影响因素以及反应过程产物.结果表明,乙酸的催化湿式氧化受到催化剂用量、反应温度、反应体系酸度以及氧分压的影响较大.当反应温度230℃,氧分压2～2.5MPa,催化剂量5g/L,反应液初始pH3.0时,反应1h后即可使乙酸浓度(以COD计)去除率在90%以上.通过离子色谱,检测了反应过程中的甲酸中间体,结果表明,催化剂的存在不仅加速了湿式氧化反应速率,而且也改变了反应历程.     

Influence factors for the oxidation of pyrite by oxygen and birnessite in aqueous systems

The oxidation of exposed pyrite causes acid mine drainage, soil acidification, and the release of toxic metal ions. As the important abiotic oxidants in supergene environments, oxygen and manganese oxides participate in the oxidation of pyrite. In this work, the oxidation processes of natural pyrite by oxygen and birnessite were studied in simulated systems, and the influence of pH, Fe(II) and Cr(III) on the intermediates and redox rate was investigated. SO₄^2 − and elemental S were formed as the major and minor products, respectively, during the oxidation processes. Ferric (hydr) oxides including Fe(OH)₃ and goethite were formed with low degree of crystallinity. Low pH and long-term reaction facilitated the formation of goethite and ferric hydroxide, respectively. The rate of pyrite oxidation by birnessite was enhanced in the presence of air (oxygen), and Fe(II) ions played a key role in the redox process. The addition of Fe(II) ions to the reaction system significantly enhanced the oxidation rate of pyrite; however, the presence of Cr(III) ions remarkably decreased the pyrite oxidation rate in aqueous systems. The introduction of Fe(II) ions to form a Fe(III)/Fe(II) redox couple facilitated the electron transfer and accelerated the oxidation rate of pyrite. The present work suggests that isolation from air and decreasing the concentration of Fe(II) ions in aqueous solutions might be effective strategies to reduce the oxidation rate of pyrite in mining soils.