Lead accumulation and association with Fe on Typha latifolia root from an urban brownfield site

Synchrotron X-ray microfluorescence and X-ray absorption near-edge microstructure spectroscopy techniques were applied to Typha latifolia (cattail) root sections and rhizosphere soils collected from a brownfield site in New Jersey to investigate lead (Pb) accumulation in T. latifolia roots and the role of iron (Fe) plaque in controlling Pb uptake. We found that Pb and Fe spatial distribution patterns in the root tissues are similar with both metals present at high concentrations mainly in the epidermis and at low concentrations in the vascular tissue (xylem and phloem), and the major Pb and Fe species in T. latifolia root are Pb(II) and Fe(III) regardless of concentration levels. The sequestration of Pb by T. latifolia roots suggests a potential low-cost remediation method (phytostabilization) to manage Pb-contaminated sediments for brownfield remediation while performing wetland rehabilitation.     

文丘里对脉冲喷吹过滤系统清灰的影响

在自建的脉冲喷吹实验台上,利用Y—YD-7044型压电式传感器和MYD-8801加速度传感器,测试0120×2000mm覆PTFE膜无纺布滤袋在不同喷吹压力下,加文丘里与不加文丘里时的最大侧壁压力峰值和最大反向加速度,并对比计算了获得同样清灰强度时的脉冲阀一次喷吹耗气量。结果显示,添加文丘里能显著增大滤袋中下部最大侧壁压力峰值和整条滤袋上的最大反向加速度,即提高脉冲喷吹清灰强度;对应同样的喷吹压力,加文丘里时的平均最大侧壁压力峰值和平均最大反向加速度比不加文丘里时分别平均提高大约70％和50％;加文丘里获得同样清灰强度时的脉冲阀一次喷吹耗气量比不加文丘里时节省40％左右。证实对于脉冲喷吹清灰系统,添加文丘里能有效改善清灰效果以及减小能量？肖耗。     

大孔树脂NKA-II对双酚A的吸附性能

研究了大孔树脂NKA-II对双酚A（BPA）的吸附性能,考察了吸附过程的动力学、热力学及树脂的再生性能。BPA溶液呈弱酸性,不需调节pH可直接进行吸附。BPA在大孔树脂NKA-II上的吸附过程可用准二级动力学方程很好地描述。树脂对BPA的吸附是吸热反应,符合Freundlich等温吸附方程,吸附过程属于可自发进行的物理吸附。BPA的吸附过程中同时存在着溶剂的解吸。大孔树脂NKA-II具有良好的重复使用性能,新树脂的平衡吸附量为10.44 mg/g,再生20次后平衡吸附量仍为10.43 mg/g。     

络合萃取法处理2-萘酚生产废水

采用络合萃取法处理2-萘酚生产废水,比较了分别以三辛胺、十二烷基二甲基胺（十二叔胺）、三烷基胺作为萃取剂的萃取效果,其中三辛胺萃取效果最佳,三烷基胺次之,十二叔胺的萃取效果最差。处理2-萘酚生产废水的最佳工艺条件为：以三辛胺作为萃取剂,萃取剂加入量为8.5%,废水pH为1.0。在此最佳工艺条件下废水的COD去除率可达97.2%。采用NaOH溶液反萃取后的萃取剂用于第二次萃取,COD去除率为96.4%,再反萃取后用于第三次萃取,COD去除率为94.9 %。萃取剂可重复使用。     

Mn的氧化价态对Mn/γ-Al2O3催化剂催化臭氧氧化气相低浓度甲苯的影响

采用共沉淀法,以Al₂O₃为载体制备Mn/γ-Al₂O₃和Mn-Ce/γ-Al₂O₃催化剂,并分别在N₂气氛和O₂气氛下焙烧。采用固定床连续流动反应器,研究所制备催化剂在室温条件下催化臭氧氧化甲苯的性能。通过XRD、XPS和FTIR等手段对催化剂的结构和组成进行表征。结果表明,Mn/γ-Al₂O₃催化剂具有良好的催化臭氧氧化甲苯和催化臭氧自身分解的性能,共沉淀法制备催化剂的最佳Mn负载量为20%。O₂气氛焙烧和Ce的加入,可以有效提高催化剂的活性和寿命。原因是O₂气氛焙烧和Ce的加入可以提高Mn的氧化价态。催化剂失活的主要原因是有机副产物在催化剂表面吸附堆积,失活催化剂在550℃、空气气氛下焙烧可恢复催化性能。     

基于DEA模型的太湖流域企业污水治理效率

运用数据包络分析DEA方法,建立了太湖殷村港流域工业园区企业污水治理效率评价体系,并利用该体系对园区内企业污水治理效率进行了实证研究。利用效率评价函数对园区内20家企业进行评价,结果表明,其中4家企业达到环境治理效率相对高效;20家企业的废水排放量、COD和NH3-N排放削减总量分别为3 691 860、217.53和14.64 t/a,削减潜力较大。实证研究结果表明,该环境绩效评价系统可为园区企业污水治理调控提出定量化的调整建议。     

诱导喷嘴改进滤筒清灰效果的数值模拟

采用计算流体动力学数值模拟方法,对规格为325 mm×660 mm滤筒在采用高效诱导喷嘴(超音速引流喷嘴和气流散射器)喷吹时的内部流场进行研究。通过分析喷吹气流在滤筒内的压力分布云图和喷嘴处的速度分布图,得出模拟结果与脉冲喷吹实验结果基本一致,验证了数值模拟的可靠性和实验的准确性。进而从微观上分析得出采用诱导喷嘴可使气流更加稳定的进入滤筒内部,以此确保滤筒长度方向上内壁清灰压力的均匀性,对滤筒清灰效果有明显的改善作用,为解决滤筒的清灰问题提供了一定的指导。     

石油降解菌的筛选优化及其对油污土壤的修复特性

分别以牛肉膏蛋白胨-布氏哈斯培养基、蓝色凝胶培养基作为初筛和复筛培养基,从石油污染土壤中筛选出2株可产生微生物表面活性剂的石油烃降解菌。并将菌株投加到油污土壤中进行修复研究,考查了不同影响因素对修复效果的影响。研究结果表明,(1)2株菌对中度石油污染土壤有较好的修复效果,向油污土壤中直接投加菌株修复70 d时对石油烃的去除率为52%;(2)向油污土壤中投加降解菌并同时补充氮营养液,修复70 d时对土壤中总石油烃的去除率可达到75%;对土壤中正构烷烃的去除率为66%;(3)与土壤的含水率及土著菌的降解效果相比,向油污土壤中投加降解菌以及补充氮磷营养液是影响石油污染土壤修复效果的关键因素。     

Design and characterization of human exposure to generated sulfate and soot particles in a pilot chamber study

A number of literatures have documented adverse health effects of exposure to fine particulate matter (PM_2.5), and secondary sulfate aerosol and black carbon may contribute to health impacts of PM_2.5 exposure. We designed an exposure system to generate sulfate and traffic soot particles, and assessed the feasibility of using it for human exposure assessment in a pilot human exposure study. In the designed exposure system, average mass concentrations of generated sulfate and soot particles were 74.19μg/m³ and 11.54μg/m³ in the chamber and did not vary significantly during two-hour human exposure sessions. The size ranges of generated sulfate were largely between 20 to 200 nm, whereas those of generated soot particles were in the size ranges of 50 to 200nm. Following two-hour exposure to generated sulfate and soot particles, we observed significant increases in fractional exhaled NO (FeNO) in young and health subjects. Building on established human exposure system and health response follow-up methods, future full-scale studies focusing on the effects of mixed particulates and individual PM_2.5 components would provide data in understanding the underpinning cardio-respiratory outcomes in relation to air pollution mixture exposure.

Implications: Controlled exposure is a useful design to measure the biological responses repeatedly following particulate exposures of target components and set exposure at target levels of health concerns. Our study provides rational and establishes method for future full-scale studies to focus on examining the effects of mixed particulates and individual PM_2.5 components.     

类氧化硅气凝胶吸附材料的制备及其吸附性能

以有机硅高沸物和Na₂SiO₃·9H₂O为原料,采用溶胶-凝胶法制备出疏水性的类氧化硅气凝胶吸附材料。采用透射电子显微镜、傅里叶变换红外分析仪和比表面与空隙度分析仪对该吸附材料的结构进行表征。表征结果显示,该吸附材料呈海绵状多孔结构,比表面积为294.48 m²/g,孔径分布较宽（为2 ~140 nm）,平均孔径为8.95 nm。实验结果表明：采用该吸附材料常温下静态吸附处理质量浓度为10 mg/L的罗丹明B（RhB）溶液,在类氧化硅气凝胶吸附材料加入量50 g/L、静态吸附时间5 h的最佳静态吸附工艺条件下,RhB去除率为98.8%,吸附后RhB质量浓度为0.124 mg/L;采用该吸附材料常温下动态吸附处理质量浓度为15 mg/L的RhB溶液,吸附4 h后开始穿透,吸附7 h后完全穿透。穿透时间较长,表明该吸附材料具有较大的吸附容量。