热态钢渣CO_2改性及热力学性能研究

钢渣是来源于炼钢过程的废弃物,其矿物组成与水泥熟料相似,但钢渣中含有较高的f-Ca O,是限制钢渣在建材领域应用的重要原因。基于此,利用CO2改性技术对钢渣进行了改性处理,并通过热力学分析对改性效果进行了验证。结果表明:热力学理论分析与实验结果具有良好的一致性,CO2作为改性气相对钢渣物相组成具有显著改性效果,改性后钢渣中f-Ca O含量可以降到1%以下。     

环境矿物材料吸附重金属的有机改性研究

环境矿物材料应用在重金属污染治理中越来越受到人们的关注,而通过有机改性可以有效提高其治理效果。结合国内外对环境矿物材料的有机改性研究,综述了应用于重金属污染治理的环境矿物材料有机改性的研究进展,并提出了发展趋势和展望。     

Implications of oxidative stress in occupational exposure to lead on a cellular level

The aim of this study was to determine oxidative alterations leading to cellular dysfunctions in Pb-exposed subjects by evaluating damage to all major classes of biomolecules in the cell, lipid peroxidation, protein and DNA damage and determine relationships between parameters of Pb toxicity and specific biomarkers of oxidative damage.

Analysis was conducted of smelter workers with high blood Pb and urine aminolevulinic acid levels and slightly elevated values of coproporphyrin and erythrocyte protoporphyrin IX. Significant decreases of thiol groups and increases in carbonyl groups as protein degradation end products, and of nitrite were detected. Elevated rates of lipid peroxidation and rises in the activities of the antioxidant enzymes Cu–Zn superoxide dismutase and catalase were also observed. Both enzymes showed positive correlations with the blood lead levels and urine coproporphyrin, while thiol groups correlated negatively with the same indices. The genotoxic potential of lead was manifested through an increased number of DNA-damaged cells. Increased activities of serum lactate dehydrogenase isoenzymes indicated cellular damage in the lungs, kidneys, and liver. These lead-induced impairments should be taken into consideration in the assessment of Pb-related health hazards.     

改性活性炭对水中PFOS的吸附去除研究

分别用FeCl3及中功率微波对煤质和椰壳2种粉末活性炭进行改性.序批式实验研究了活性炭改性前后对全氟辛烷磺酸(PFOS)的吸附特性.结合活性炭改性前后表面化学官能团和孔结构的变化特征,探讨了不同改性方式对PFOS吸附去除的影响效应以及天然有机物中的主要组成成分腐殖酸对PFOS在原炭及改性炭上的竞争吸附效应.结果表明,Fe3+及中功率微波处理对煤质炭和椰壳炭的孔结构和表面性质都有影响,但变化趋势不同.椰壳活性炭经Fe3+及中功率微波改性后对PFOS的吸附量明显提高,而煤质活性炭经改性后对PFOS的吸附量出现下降.改性椰壳活性炭与原炭吸附PFOS达到吸附平衡的时间基本相同,均为6 h左右.在腐殖酸存在下,改性椰壳炭对PFOS的吸附量因竞争吸附而有所下降,但改性炭的吸附量仍明显高于原炭.     

Zn系LDHs覆膜改性人工湿地沸石基质除磷机制

选择Zn系层状双金属氢氧化物(LDHs),采用水热-共沉淀法合成3种不同类型的Zn-LDHs(Fe Zn-LDHs、Co Zn-LDHs和Al Zn-LDHs)并覆膜于常用人工湿地沸石基质表面;利用模拟垂直流人工湿地小试系统,对原始沸石及3种Zn-LDHs覆膜改性沸石基质进行除磷净化实验、等温吸附-解吸实验以及动力学吸附实验,通过上述实验对以Zn-LDHs覆膜改性沸石基质为代表的改性基质除磷机制进行研究.结果表明,Zn-LDHs覆膜改性沸石基质对磷素净化效果具有明显的提升功能,其中以Fe Zn-LDHs覆膜改性基质尤为突出;改性使基质的饱和吸附容量得以提高,增强了基质对磷酸盐的解吸性能,并使沸石基质对磷酸盐的主要吸附类型由物理吸附向化学吸附转换;通过对沸石基质类型及其改性方式的合理选择,可达到利用沸石人工湿地强化除磷以高效净化富营养化水体的目的.     

酸碱改性活性炭及其对甲苯吸附的影响

分别用酸溶液(H_2SO_4、HNO_3、H_3PO_4)和碱溶液(NaOH或NH_3·H_2O)浸渍方法对活性炭进行改性,并对酸改性活性炭进行碱溶液二次改性处理,通过表征改性前后活性炭BET比表面积、孔结构、表面官能团等理化特征和测定其对甲苯蒸气的饱和吸附量,研究了影响活性炭吸附甲苯蒸气的关键因素.结果表明,酸改性使BET比表面积、微孔面积、微孔容积减少、表面酸性官能团增加,而碱改性呈现相反的理化特征变化.活性炭理化特征的变化可能与改性溶液的酸碱性、氧化还原性有关,并且这种相反的变化直接关系到活性炭对甲苯蒸气的吸附.3种酸改性的活性炭对甲苯蒸气饱和吸附量相对于原活性炭减少9.6%~20.0%,而两种碱改性的活性炭则增加29.2%~39.2%.相关性分析显示甲苯吸附量与BET比表面积、微孔面积、微孔容积正相关,而与表面酸性官能团负相关;多元回归分析进一步表明微孔容积和酸性官能团数量是影响活性炭甲苯吸附的关键因素.二次改性活性炭甲苯吸附量与表面含氧酸性官能团拟合结果则表明,—COOH、C＝O和—OH都对活性炭甲苯吸附能力有影响,其中—COOH影响较大.研究结果表明有效提高活性炭对甲苯吸附能力,改性宜以提高活性炭微孔容积和减小活性炭表面酸性官能团数量,特别是—COOH数量为目标导向.     

应用于Anammox-MBR的尼龙织布亲水改性研究

采用聚乙烯醇（PVA）对尼龙织布表面涂覆改性，对改性前后织布进行表征并进行纯水通量测试，随后以牛血清蛋白（BSA）模拟污染物测试尼龙织布改性前后的抗污染性能，并对改性后的织布进行溶解性有机碳（DOC）浸出实验.改性过程中，优选3%涂覆浓度和250μm涂层厚度，改性后织布的纯水通量值约提高85.0%，对BSA的截留率由6.0%±0.5%上升至7.2%±0.7%，通量恢复率由90.0%提高到96.1%，可逆污染比重上升，不可逆污染比重下降，污染形式主要表现为可逆污染.为避免改性尼龙织布应用于厌氧氨氧化-膜生物反应器（Anammox-MBR）时对厌氧氨氧化反应产生不可逆危害，提出应对制备完成的改性尼龙织布进行为期3d及以上的静态清水浸泡或动态浸出处理.     

ENVIRONMENTAL IMPACT OF CHANNEL MODIFICATION1

ABSTRACT: The purpose of this literature review is to identify and quantify the effects of channelization and to examine the feasibility and acceptability of alternative methods of flood control. In the past 150 years, over 200,000 miles of stream channels have been modified. Channelization can affect the environment by draining wetland, cutting off oxbows and meanders, clearing floodplain hardwoods, lowering ground water levels, reducing ground water recharge from stream flow, and increasing erosion sedimentation, channel maintenance, and downstream flooding. Channelization reduces the size, number, and species diversity of fish in streams. In a wet climate, the fishery requires less than 10 years to fully recover. However, in the drier climates, the fishery may never fully recover. In general, channel modifications have performed as designed for flood abatement. The Arthur D. Little Study (1973) reported that direct benefits estimated during channelization planning have been conservative and that damage reduction has been impressive. Diking seems to be a viable alternative to channel dredging. Dikes minimize destruction of wetland and eliminate the need for removing vegetation from the existing stream banks.     

CHANNEL MODIFICATION AND MACROINVERTEBRATE COMMUNITY DIVERSITY IN SMALL STREAMS1

ABSTRACT: The principal objective of this study was to investigate the long-term, temporal effect of channel modification in the diversity of macroinvertebrates. Correlation analyses suggest that aquatic macroinvertebrate communities stabilize shortly after channel modification. This conclusion is based on correlation analyses including five widely accepted diversity indices for stream reaches that have undergone channel work from less than 1 year to more than 30 years prior to the study.     

自制Cu-Bi2WO6的表征及其对苯酚的光催化降解

采用水热反应法制备Cu改性的Bi2WO6催化剂(Cu-Bi2WO6).采用XRD仪和紫外-可见光漫反射吸收光谱仪对自制Cu-Bi2WO6的结构进行了表征.考察了光催化降解工艺对Cu-Bi2WO6在可见光下催化氧化降解苯酚效果的影响.实验结果表明:自制Cu-Bi2WO6的吸收边带出现了明显红移,对可见光的利用率较Bi2WO6强;当水热反应pH为0.6时,Cu-Bi2WO6的光催化性能最好;在空气通入量为250 mL/min、Cu-Bi2WO6加入量为1.0 mg/L的条件下,光照反应210 min后苯酚降解率可达92.0％.