混凝过滤处理校园洗涤废水回用的实验研究

通过3种混凝剂和添加助凝剂的对比实验,找出适合的混凝剂和投加量,然后采用混凝过滤的方法处理校园洗涤废水.实验结果表明,在去除浊度、COD和投加量方面,复合高效聚合氯化铝(净水灵)比聚合硫酸铁(PF5)和聚合氯化铝(PAC)用量少、去除率高.投加助凝剂聚丙烯酸胺(PAM)效果不明显.不添加助凝剂,净水灵投加量40mg/L...     

驻极体空气过滤材料在呼吸防护用品中的应用

本文主要介绍了驻极体空气过滤材料在呼吸防护用品中的应用、制备以及抗菌性能、耐清洗性能、耐溶剂性能、稳定性等性能特性,并说明驻极体空气过滤材料是一类非常有应用前景的呼吸防护用品材料。     

Removal efficiencies of natural and synthetic progesterones in hospital wastewater treated by different disinfection processes

● The concentrations of 61 progesterones in HWW, PFTE, SBTE were evaluated. ● The removal efficiencies of progesterones by PFT and SBT were identified. ● Compared the removal efficiencies of progeste rones in five disinfection processes. Progesterones are ubiquitous in hospital wastewater (HWW) with concentrations much higher than those of estrogens and androgens. To ensure that these water systems are safe to use, disinfection is crucial during HWW treatment by providing “front line” defense against biological contaminations. Here, five disinfection processes, namely, chlorine (Cl₂), chlorine dioxide (ClO₂), ozone (O₃), ultraviolet (UV)), and UV/chlorine (UV/Cl₂), were selected to investigate their removal efficiencies for progesterones in primary filtration and secondary biological treatment effluents. There were 61 natural and synthetic progesterones detected in HWW, with the natural progesterones being the main components with a concentration of 845.51 ng/L and contributing to 75.08% of the total progesterones. The primary filtration treatment presented insignificant removal effects on the progesterones, while the secondary biological treatment significantly reduced the progesterone content by biodegradation. The order of removal efficiencies of total progesterones by different disinfection processes was UV/Cl₂ > Cl ₂ > O ₃ > ClO ₂ > UV. UV/Cl ₂ showed the highest removal efficiency against progesterones mainly due to the activation of Cl₂ by ultraviolet (UV) photolysis, which helps open the heterocyclic, aromatic, and phenolic rings, thus accelerating progesterone degradation. In addition, the removal efficiencies of natural progesterones in the five disinfection processes were higher than those of synthetic progesterones (progesterone derivatives, 19-nortestosterone derivatives, and 17α-hydroxyprogesterone derivatives).     

Effect of BPA on the germination,root development,seedling growth and leaf differentiation under different light conditions in Arabidopsis thaliana

Bisphenol A (BPA) is a well-known environmental toxic substance, which exerts unfavorable effects through endocrine disruptor (ER)-dependent and ER-independent mechanisms to threaten ecological systems seriously. BPA may also interact with other environmental factors, such as light and heavy metals, to have a synergetic effect in plants. However, there is little data concerning the toxic effect of BPA on the primary producers-plants and its possible interaction with light-dependent response. Here, the effects of BPA on germination, fresh weight, tap root length, and leaf differentiation were studied in Arabidopsis thaliana under different parts of light spectrum (dark, red, yellow, green, blue, and white light). Our results showed that low-dose BPA (1.0, 5.0 μM) caused an increase in the fresh weight, the tap root length and the lateral root formation of A. thaliana seedlings, while high-dose BPA (10.0, 25.0 μM) show an inhibition effect in a dose-dependent manner. Unlike karrikins, the effects of BPA on germination fresh weight and tap roots length under various light conditions are similar, which imply that BPA has no notable role in priming light response in germination and early seedling growth in A. thaliana. Meanwhile, BPA exposure influences the differentiation of A. thaliana leaf blade significantly in a light-dependent manner with little to no effect in dark and clear effect under red illumination.     

华北平原耕作土壤特性对基因工程菌迁移的影响

基因工程菌在土壤中的迁移是影响污染土壤生物强化修复的重要因素.在华北平原饱和耕作土壤中,考察了1株阿特拉津降解基因工程菌迁移留存及其影响因素.结果表明,在饱和耕作土壤中,平流渗透是基因工程菌迁移的主要机制,其过程可用过滤模型拟合.土壤性质对孔隙水流和基因工程菌迁移具有显著影响.随着土壤粒径、孔隙率和土壤砂粒组分增加,土壤水力传导率常数增大,基因工程菌过滤系数减小,土壤对基因工程菌过滤留存作用降低.土壤条件不变时,增加入渗流量也会增大土壤水力传导率常数,减小基因工程菌过滤系数.饱和土壤中,水力传导率常数为5.02~6.70 m·d-1时,基因工程菌在土壤中的过滤系数为0.105~0.274,二者存在显著负相关关系.     

Fenton法预处理垃圾渗滤液膜滤浓缩液的研究

采用Fenton法对垃圾渗滤液膜滤浓缩液进行预处理,探讨了pH值、FeSO4/H2O2用量及比例、以及反应时间对CODcr及色度去除率的影响.研究结果表明:当pH =4.0,FeSO4/H2O2用量0.75/7.5 (g/ml),反应时间2.5h,垃圾渗滤液膜滤浓缩液的CODcr浓度从4 416 mg/L降低至630.7 ml/L,CODcr去除率达85.7％;色度从1 250倍降低至200倍以下,色度去除率达84％.因此,本工艺对垃圾渗滤液膜滤浓缩液的CODcr及色度具有较好的去除效果,作为垃圾渗滤液膜滤浓缩液的预处理工艺具有可行性.     

关于垃圾填埋场渗滤液处理工艺的探讨

渗滤液的处理一直是生活垃圾填埋场存在的一大问题,尤其是新标准执行以来,对渗滤液的排放提出了更加严格的要求,因此处理工艺的选择成为达标排放的关键问题,本文中的“厌氧＋生化＋超滤＋纳滤＋反渗透”组合型渗滤液处理工艺能够确保污染物达标排放,并同时能满足处理后废水综合利用的要求。     

混凝预处理及膜面流速控制对微滤膜污染的影响研究

为研究膜面流速和混凝预处理对微滤过程膜污染的综合影响,用旋流式膜混凝反应器进行了不同流量、入口管径、混凝剂投加量下的除浊试验。结果表明,直接微滤时,高膜面流速加剧了初期膜的孔堵污染,但抑制了滤饼层的累积,适于长期运行;在质量浓度为0~18 mg/L范围内增大聚合氯化铝（PAC）投加量可显著抑制膜过滤阻力的增长;以速度梯度（G）表征絮体状态,由于絮体尺寸和错流的综合作用,投加混凝剂后,G在20~70 s-1范围内,414.64 s-1时微滤膜污染较轻。     

Fault propagation behavior study and root cause reasoning with dynamic Bayesian network based framework

The Bhopal disaster was a gas leak incident in India, considered the world's worst industrial disaster happened around process facilities. Nowadays the process facilities in petrochemical industries have becoming increasingly large and automatic. There are many risk factors with complex relationships among them. Unfortunately, some operators have poor access to abnormal situation management experience due to the lack of knowledge. However these interdependencies are seldom accounted for in current risk and safety analyses, which also belonged to the main factor causing Bhopal tragedy. Fault propagation behavior of process system is studied in this paper, and a dynamic Bayesian network based framework for root cause reasoning is proposed to deal with abnormal situation. It will help operators to fully understand the relationships among all the risk factors, identify the causes that lead to the abnormal situations, and consider all available safety measures to cope with the situation. Examples from a case study for process facilities are included to illustrate the effectiveness of the proposed approach. It also provides a method to help us do things better in the future and to make sure that another such terrible accident never happens again.     

不同织物构造PPS滤料对PM2.5的过滤特性影响分析

针对纤维细度、纤维横截面形状、面层后处理工艺对PM2.5的过滤效率及阻力的影响问题,分别选用1#面层含100％ 2.22 dtex PPS纤维经PTFE浸渍、2#面层含50％ PPS细纤维不经PTFE浸渍、3#面层含50％ PPS细纤维经PTFE浸渍、4#面层含50％ PPS三叶形纤维不经PTFE浸渍、5#面层含50％ PPS三叶形纤维经PTFE浸渍、6#面层PTFE覆膜、7#面层含50％ PPS细纤维和50％ PTFE超细纤维的7种PPS滤料进行过滤性能试验.在环境气溶胶中,采用清洁滤料进行过滤试验研究.结果表明,1 m/min风速下对PM2.5的过滤效率从大到小为6#(81％)、7#(80％)、3#(76％)、5#(72％)、1#(63％)、2#(47％)、4#(41％),各因素中PTFE乳液浸渍后处理工艺的影响最为显著,面层纤维采用细纤维截面设计和三叶形截面设计都能有效增加滤料对PM2.5的过滤效率.过滤阻力方面,6#覆膜滤料随过滤风速增大阻力迅速上升;其他6种滤料的阻力较接近,上升缓慢.过滤品质因数Q值方面,相对于常规滤料,面层中混入细纤维或三叶形纤维滤料的Q增大;提高面层中细纤维比例,也能使Q增大;覆膜滤料效率虽高,但阻力较大,Q最小.