厌氧折流板反应器处理玉米秆纤维浆粕废水的研究

采用厌氧折流板反应器 (ABR)处理玉米秆纤维浆粕废水 ,研究了工艺条件和工艺特征。试验结果表明 ,在HRT为 2 4h ,OLR为 6 .5 6kgCOD/m3 ·d条件下 ,ABR能有效处理浓度为 6 5 6 0mgCOD/L的玉米秆纤维浆粕废水 ,COD去除率为 75 .1% ;ABR对负荷冲击有良好的适应性 ,且具有推流式和两相式反应器的双重特点。     

鼓泡式UV-Fenton法处理二甲苯废气

采用UV-Fenton法在自制鼓泡反应装置中处理二甲苯废气,考察了pH值、H2O2投加量、Fe2+浓度和气体停留时间等操作条件对二甲苯废气处理效果的影响,并分析了UV与Fenton技术的协同效应。研究表明,pH、停留时间（EBRT）、双氧水投加量及气液接触效率对二甲苯去除效果影响显著,少量批次投加双氧水可以显著提高其利用效率。UV-Fenton体系的最佳反应条件为：pH=3,H2O2每隔半小时投加一次且投加量为0.01%·次-1,Fe2+浓度为40 mg·L-1,EBRT为55 s,紫外波长为254 nm。UV和Fenton在反应过程存在较强的协同效应,协同因子达到81%以上。     

高炉细灰冷压成型回收铁锌

在资源短缺和环保形势日益严峻的情况下,高炉细灰的回收再利用逐渐被人们重视。XRF、SEM、EDS和XRD分析确定了细灰的元素含量、分布状态、颗粒形貌及物相组成。高炉细灰原样和添加5%的CaCO3的高炉细灰的TG-DSC分析表明细灰冷压块高温焙烧的最低温度应为950℃。按一定比例的马铃薯全粉和水配加不同比例的CaO制备复合黏结剂,配加到高炉细灰中压块并测定强度,当CaO含量在7%时,压块强度最大。在充入保护性气氛N2的管式炉中,950、1 050、1 150、1 250℃,分别焙烧CaO配比为7%的压块1 h,分析结果表明1 150℃时细灰去Zn效果良好,焙烧所得物质主要为Fe。该工艺除可以调节细灰的碱度外,也可以有效利用马铃薯全粉。     

小尺度农田土壤Pb、Zn和Cd空间分布及污染评价——以云南沘比江沿岸某农田为例

以沘江沿岸面积为96 000 m2的整片农田作为研究对象,采集144个表层土壤样本,利用ICP-MS测定土壤中Pb、Zn和Cd的含量,使用地统计学方法分析Pb、Zn和Cd的空间分布,采用污染负荷指数评价土壤Pb、Zn和Cd污染程度,并对污染来源进行解析。结果表明研究区域农田土壤中Pb、Zn和Cd含量均超过当地土壤背景值,出现了污染富积。根据国家土壤环境质量标准,Pb未超标,Zn超标率为98.6%,Cd超标率为100%。普通克里金空间插值分布图显示,Pb、Zn和Cd高含量区域均沿着省道227和靠近居民区分布,而临近沘江的区域Pb、Zn和Cd含量相对较低,其中Pb、Zn含量变化基本呈现由省道227向沘江方向递减规律。Pb、Zn和Cd之间具有较好的相关性,三者同源概率较大。对Pb、Zn和Cd的污染评价表明,研究区域农田土壤57.78%为中度污染,42.22%为重度污染。从污染负荷指数法（PLI）空间插值图可见,重度污染区域位于省道227沿线与居民区东侧区域,其余区域为中度污染。本研究结果说明,小尺度空间分析方法用于农田土壤污染状况的分析,能有效预测重金属空间分布情况,在土地紧缺的情况下,该方法能有效指导对农田的不同区域进行选择使用和精准管理。     

Co-surfactant of ethoxylated sorbitan ester and sorbitan monooleate for enhanced flushing of tetrachloroethylene

This work evaluated the flushing efficiency of tetrachloroethylene (PCE) using the co-surfactant of non-ionic ethoxylated sorbitan ester (Tween) and oilphilic sorbitan monooleate (Span 80), which formed more hydrophobic micelles than Tween alone. The flushing efficiency was evaluated with laboratory columns filled with silica and aquifer sand. Results from column flushing were also compared to those of batch solubility experiments to study the removal mechanism by the co-surfactant solution. Compared to Tween 80 alone, the molar solubilization ratio and the affinity between the micelles and PCE increased 84% and 90%, respectively, by the co-surfactant solution of Tween 80 and Span 80 mixed at a 4:1 ratio. Flushing with 1% Tween 80 solution yielded a steady PCE recovery of 7% for both silica and aquifer sand in each pore volume (PV). Flushing with co-surfactant of 1% Tween 80 + Span 80 (4:1) further increased PCE recovery to 10% for silica sand and 13% for aquifer sand per PV. A comparison of results from column flushing and batch solubility tests indicated that the primary flushing mechanism of PCE using the co-surfactant solution of Tween 80 + Span 80 (4:1) was micellar solubilization.     

Heavy metal pollution in sediments of the largest reservoir (Three Gorges Reservoir) in China: a review

The Three Gorges Dam in China is the world’s largest dam. Upon its completion in 2003, the Three Gorges Reservoir (TGR) became the largest reservoir in China and plays an important role in economic development and national drinking water safety. However, as a sink and source of heavy metals, there is a lack of continuous and comparative data on heavy metal pollution in sediments. This study reviewed all available literatures published on heavy metals in TGR sediments and further provided a comprehensive assessment of the pollution tendency of these heavy metals. The results showed that heavy metal concentrations in TGR sediments varied spatially and temporally. Temporal variations indicated that Hg in tributaries, as well as As, Cd, Cr, Cu, Ni, Pb, and Zn in the mainstream, exhibited a higher probability to exceed background values after the impoundment of TGR. Pollution assessments by contamination factor, geoaccumulation index, and potential ecological risk were similar. High Cd and Hg concentrations in both the mainstream and tributaries are a cause for much concern. However, sediment quality guidelines produced different results, as most previous studies adopted different sampling and measurement strategies. The data inconsistencies and lack of continuity regarding the reservoir confirm the need for a continuous monitoring network and the development of quality criteria relevant to the sediments of the TGR in the future.     

反硝化除磷的影响特性试验

采用SBR反应器（厌氧/缺氧/好氧工艺）,分别研究了乙酸盐及硝酸盐浓度变化对反硝化除磷的影响特性.试验结果表明,当进水COD浓度＞230 mg/L时,乙酸盐浓度的变化对释磷、除磷速率等影响并不显著.在硝酸盐浓度＜30 mg/L时,硝酸盐浓度越高,缺氧段除磷速率也就越高.在C/P＞23,C/N＞5条件下,SBR系统对磷、氮去除率在90%以上.     

农药对藻类的生态毒理学研究Ⅰ:毒性效应

随着现代农业的发展,世界范围内使用的农药品种越来越多,用量不断增加。农药对非靶生物的影响以及农药残留导致环境污染,造成生态系统结构和功能的破坏,早已受到了国内外的广泛关注。有关农药对生态系统中消费者类群毒性效应的研究较多。近年来,农药对于生态系统初级生产者－ 藻类的毒性及其生态毒理学的研究倍受重视。大力开展这方面的研究对于深入了解农药在生态系统中的迁移、转化及整体生态效应以及农药的生态风险评价无疑具有重要的理论意义和应用价值。本文综述了近年来国内外有关农药对单种藻类和藻类群落的毒性效应,影响毒性的环境因子。     

改性粉煤灰及其处理废水的机理

应用正交设计的基本理论,研究了PDMDAAC(聚二甲基二烯丙基氯化铵)改性粉煤灰的最佳条件,并将改性粉煤灰用于模拟印染废水的处理,探索了改性粉煤灰处理废水的机理。结果表明,在原PDMDAAC的pH下．控制PDMDAAC的浓度为40g／L,恒温30℃．反应1h为最佳改性工艺,改性粉煤灰处理废水的机理以吸附电中和为主。     

选煤脱除氟、砷的研究

研究了采自西南3省、1市17个选煤厂的原煤和洗精煤样品,分析了灰分、氟和砷含量,探讨了选煤脱除氟、砷的机理和影响因素。结果表明,选煤能有效降低煤中氟、砷的含量,应用前景广阔。