氧化石墨烯抗菌性及生物安全性研究进展

氧化石墨烯是一种表面有丰富含氧官能团的石墨烯衍生物,具有与石墨烯相似的二维蜂窝状晶格结构,从而导致了其具有电学、光学、力学特性和良好的生物相容性,被广泛应用于材料学、生物医学和药物传递等诸多领域。因氧化石墨烯日益增多的生产和使用,其在空气、水和土壤中大量积累,引发了人们对其生物安全性的高度关注。以微生物、陆生动植物和水生动植物为分类标准,综述了近几年氧化石墨烯对微生物、动物和植物的毒性影响,总结并分析了三者的毒性机理,比较了不同生存环境下其对动植物毒性影响的不同,旨在更加全面地揭示氧化石墨烯的生物安全性,为氧化石墨烯安全使用剂量和其功能化应用提供一定的参考。     

高效降解菌处理高浓度焦化废水

为了解决高浓度焦化废水不经稀释无法直接处理的问题,将HENGJIE高效混合菌制剂和粉末活性炭加入O1AO2废水处理系统中,进行焦化废水的中试试验。试验结果表明,该方法可对未经稀释的高浓度焦化废水直接进行处理,且系统启动快,菌种对污染物的降解效率较高。在O1段水力停留时间为20h、A段水力停留时间为35h、O2段水力停留时间为25h的条件下,经过20d的连续运行后,使进水COD由5435．7mg／L（平均值）降至出水COD369．3mg／L（平均值）,COD去除率为93．17％;使进水中NH3-N平均质量浓度由67．80mg／L降至出水中NH3-N平均质量浓度1．04mg／L,NH3-N去除率为98．18％,废水色度为100～200。除废水COD与色度外,其他检测项目均可达到废水一级排放标准。     

文丘里陈尘器喉管结构的优化设计

应用文献中计算压降的公式,得出压降随喉管长度变化的关系;应用William Licht效率公式,得出效率及效率、压降比随喉管长度和喉管气速的变化关系.根据这些关系,得出了在给定效率下压降最小时相应的喉管直径和管长的最佳组合.该结果对于优化文丘里除尘器喉管结构设计、降低能耗和运行成本具有重要意义.     

全球气温上升因素研究--能源利用中热能散失对气温的影响

为了分析能源不完全利用产生的热能散失对近三十年来全球气温升高的影响,首先对近三十年来的全球气温、主要温室气体浓度和主要能源利用中的热能散失量等数据进行了收集和整理;结合各温室气体对温室效应的相对贡献值引入了温室效应值这一参数,之后通过二元线性回归法来分析温室效应和能耗散失双因素对气温升高的权重影响.借助于黑体辐射定律等相关物理模型,估算出分别由此二因素引起的全球气温升高值,并对两者贡献值进行了量化比较,结果表明,虽然温室效应是气温升高的主要原因,但热能散失也对这一气候变化具有一定程度的影响.     

Differences in the treatment efficiency of a cold-resistant floating bed plant receiving two types of low-pollution wastewater

A floating bed system vegetated with Oenanthe javanica was adopted in this study to treat two types of low-pollution wastewater (LPW): polluted river water (PRW) and treated domestic wastewater (DW). The water was treated for 111 days during the low-temperature season. The results indicated that the total nitrogen (TN) removal rates were higher in the DW groups than in the PRW groups during the initial 30 days. This difference may stem from the different C/N ratio of the influent. As the water temperature rose above 15.5 °C after March 12, the purification capability of nitrogen in the DW groups was enhanced, and the removal rates of TN were 89.8 and 76.8 % in DW and the control 2 at 111 days. Conversely, the performance of total phosphorus (TP) removal was robust during the initial stage of the experiment, despite receiving domestic wastewater with a relatively high N/P ratio (16:1). The TP removal rates in DW were as high as 91.5 % compared to 78.9 % in PRW at 30 days. At the same time, the N/P ratios of plant tissue were higher in the DW groups compared to that in the PRW groups. Plant uptake played a significant role in nutrient removal in the PRW groups (52.5 % for TN, 68.2 % for TP), followed by sedimentation. In contrast, plant uptake only accounted for 25.3 % of TN removal and 24.1 % of TP removal in DW. The results provide engineering parameters for the future design of an ecological remediation technology for LPW purification.     

固载型TiO2光催化反应器对富营养水体杀藻作用研究

以泡沫镍作为载体,利用电沉积技术将纳米TiO2负载在泡沫镍上,制成固载型TiO2光催化反应器.研究表明,经过光催化反应器处理的富营养水体,30 h内叶绿素a由96.2 mg/m3降至2.2 mg/m3,下降率达97.6%,而未负载纳米TiO2普通泡沫镍材料,在同样光强的紫外灯照射下,叶绿素a下降率为74.3%,表明紫外光照射虽然也具有一定的杀藻功能,但是光催化反应才是藻类被杀灭的主要原因.利用9.54 m3景观喷水池进行杀藻中试,光催化反应器也同样表现出优异的杀藻性能,12 d内叶绿素a由18.7 mg/m3降至1.9 mg/m3,下降率达到89.8%,水体由浓绿变为清澈见底,这表明光催化反应器具有很强的杀藻能力,通过有效杀灭富营养水体中藻类、控制藻类基数,对应急处理城市景观水、湖泊等富营养水体和突发性藻华,提高生物-生态法处理效率,改善城市水环境具有十分重要的意义.     

Quantification and fractionation of mercury in soils from the Chatian mercury mining deposit,southwestern China

Contents of total Hg and Hg fraction, organic matter, pH, grain size and chemical composition were measured to investigate the pollution characteristics and binding behavior of Hg in soils collected from the Chatian Hg mining deposit (CMD), southwestern China. The average concentration of Hg concentration in the CMD soils was 155 and 1,315 times higher than that in control soils and Chinese soils, respectively, suggesting that the CMD soils were heavily contaminated by the element. The finding was confirmed by Müller geoaccumulation index assessment with 75% very seriously polluted, 6.25% highly to very highly polluted and 18.75% moderately to highly polluted. Hg sources in the region were natural and anthropogenic: in addition to the pedogenic process and original geochemical situation, human mining–refining activities have also seriously impacted the redistribution of Hg in soils, especially in paddy soils. Based on the BCR protocol, soil Hg was divided into exchangeable (EXC), amorphous Fe–Mn oxides (AFe–MnOX), organic-crystalline iron oxides (OM-CFe) and residual (RES) fraction. The average percentage of the four fractions in the CMD followed the trend: RES (85.77%) > OM-CFe (12.44%) > AFe–MnOX (0.93%) ≥ EXC (0.86%), suggesting that the majority proportion of soil Hg in the study area remained of residual form inside the soil mineral matrix. However, their concentrations and percentages significantly varied among different locations and land use types. Soil physico-chemical parameters were key factors affecting the presence of Hg fraction. Generally, Hg fraction concentrations were positively correlated with the sand contents and soil pH values, which was presumably due to the basic anthropogenic input of Hg-containing materials and their similarity to sand in physical characteristics. However, organic matter caused adsorption–fixation and reduction–volatilization to coexist, which had opposite effects on Hg concentrations in soil, consequently exhibiting its dual nature.     

板框压滤机内酒精污泥过滤脱水特性

采用螺杆泵输送和板框过滤机压滤的方法对酒精污泥进行机械脱水,研究了絮凝剂(聚丙烯酰胺PAM)添加量、污泥的进口湿含量、螺杆泵转速、过滤介质和过滤时间对污泥过滤特性的影响,并对滤饼吹气压榨进一步脱水。实验表明,在PAM添加量wPAM=3 kg/(t干污泥),污泥的进口湿含量x0=95%,螺杆泵转速n=180 r/min,过滤时间t=2.5 h并进行吹气压榨可将污泥的湿含量降至69.91%。     

臭氧光电催化耦合处理炼油反渗透浓水

为控制炼油废水对环境的污染,采用臭氧光电催化氧化耦合工艺对炼油废水反渗透浓水进行了处理研究,主要考察了pH、电流密度、臭氧投加量等因素对该耦合体系废水处理效果的影响。结果表明,臭氧光电催化氧化耦合技术可有效降解炼油废水反渗透浓水;废水中油类及COD的去除率随pH的增大先提高后降低;随电流密度的增大,COD去除率先提高后降低,油类物质先提高然后基本保持恒定;臭氧投加量不断增大,COD及油类物质去除率先提高后趋于稳定。当pH=7.5,臭氧投加量达到8 mg/L,电流密度50 mA/cm2,停留时间30 min,出水达到COD≤50 mg/L,石油类≤0.5 mg/L的排放要求。     

丙烯酰胺接枝木薯淀粉的合成及橡胶废水的絮凝处理

以丙烯酰胺为单体,过硫酸铵为引发剂,十二烷基磺酸钠为乳化剂,采用乳液聚合法合成丙烯酰胺接枝木薯淀粉(接枝淀粉)。实验结果表明:当m(淀粉)∶m(单体)为1.0∶1.5、合成温度为60℃、引发剂加入量(质量分数)为2.4%时,单体转化率、接枝率和接枝效率分别为74.7%,69.8%,74.9%;当接枝淀粉的加入量为0.35g/L时,絮凝处理后橡胶废水的吸光度由0.164降为0.073,脱色率为55.5%。