约束屈曲纵筋摇摆柱滞回性能研究∗

提出了一种新型约束屈曲纵筋摇摆柱构造,即在传统钢筋混凝土柱中采用约束屈曲纵筋代替普通钢筋并放松柱与基础的约束而形成的一种新型摇摆柱,并提出了相应的恢复力模型。对约束屈曲纵筋进行了单调受压试验和数值模拟,验证了约束屈曲装置对纵筋的约束功能并研究了钢筋直径、约束屈曲装置与钢筋间空隙对其约束功能的影响;对约束屈曲纵筋摇摆柱进行了数值模拟,研究纵筋直径以及轴压比对其滞回性能的影响。结果表明:约束屈曲纵筋摇摆柱的滞回曲线为典型旗帜型,其强度为混凝土部分强度和纵筋部分强度叠加,柱的摇摆发生在受拉侧纵筋屈服之后。通过设计可使结构在小震阶段不摇摆,中震阶段柱纵筋屈服结构发生摇摆。轴压比以及纵筋直径的增加都可以在不同程度增加约束屈曲纵筋摇摆柱的侧向承载能力。     

污水处理厂恶臭污染物的工程治理

介绍了某纺织公司水质净化中心厂区恶臭污染物的治理方案。恶臭气体主要是H2S,质量浓度达6．0mg/m^3。将臭气引至除臭塔,塔内设嚣填料。挣化后的气体达到了GB1455-93中的二级标准0．06mg／m^3。     

Effect of nitrobenzene on the performance and bacterial community in an expanded granular sludge bed reactor treating high-sulfate organic wastewater

Less than 50 mg/L nitrobenzene brought little effect on anaerobic sulfate reduction. Kinetics of sulfate reduction under different nitrobenzene contents was studied. Increased nitrobenzene contents greatly changed the bacterial community structure. Genus Desulfovibrio played the key role in anaerobic sulfate reduction process. Nitrobenzene (NB) is frequently found in wastewaters containing sulfate and may affect biological sulfate reduction process, but information is limited on the responses of sulfate reduction efficiency and microbial community to the increased NB contents. In this study, a laboratory-scale expanded granular sludge bed reactor was operated continuously to treat high-sulfate organic wastewater with increased NB contents. Results successfully demonstrated that the presence of more than 50 mg/L NB depressed sulfate reduction and such inhibition was partly reversible. Bath experiments showed that the maximum specific desulfuration activity (SDA) decreased from 135.80 mg SO₄^2?/gVSS/d to 30.78 mg SO₄^2?/gVSS/d when the NB contents increased from none to 400 mg/L. High-throughput sequencing showed that NB also greatly affected bacterial community structure. Bacteroidetes dominated in the bioreactor. The abundance of Proteobacteria increased with NB addition while Firmicutes presented an opposite trend. Proteobacteria gradually replaced Firmicutes for the dominance in response to the increase of influent NB concentrations. The genus Desulfovibrio was the dominant sulfate-reducing bacteria (SRB) with absence or presence of NB, but was inhibited under high content of NB. The results provided better understanding for the biological sulfate reduction under NB stress.     

Identification of sources,characteristics and photochemical transformations of dissolved organic matter with EEM-PARAFAC in the Wei River of China

• The source of DOM in surface water and sediment is inconsistent. • The DOC content changes differently in surface water and sediment. • The content of DOC in the surface water is lower than that in the sediment. • The DOM in the surface water had higher photodegradation potentials than sediment. Dissolved organic matter (DOM) in rivers is a critical regulator of the cycling and toxicity of pollutants and the behavior of DOM is a key indicator for the health of the environment. We investigated the sources and characteristics of DOM in surface water and sediment samples of the Wei River, China. Dissolved organic carbon (DOC) concentration and ultraviolet absorbance at 254 nm (UV₂₅₄) increased in the surface water and were decreased in the sediment downstream, indicating that the source of DOM in the water differed from the sediment. Parallel factor (PARAFAC) analysis of the excitation-emission matrices (EEM) revealed the presence of terrestrial humus-like, microbial humus-like and tryptophan-like proteins in the surface water, whereas the sediment contained UVA humic-like, UVC humic-like and fulvic-like in the sediment. The DOM in the surface water and sediment were mainly derived from microbial metabolic activity and the surrounding soil. Surface water DOM displayed greater photodegradation potential than sediment DOM. PARAFAC analysis indicated that the terrestrial humic-like substance in the water and the fulvic-like component in the sediment decomposed more rapidly. These data describe the characteristics of DOM in the Wei River and are crucial to understanding the fluctuations in environmental patterns.     

Efficient metoprolol degradation by heterogeneous copper ferrite/sulfite reaction

Metal/sulfite systems are currently used for SO ₄ ^?? generation and oxidative removal of organic contaminants. However, homogeneous metal/sulfite systems are limited because their working pHs must be acidic and metal ions cannot be separated from the bulk reaction solution. As a consequence, these drawbacks have severely limited the application of metal/sulfite systems in real conditions. To address these issues, we tested the use of copper ferrite (CuFe₂O₄), a ferromagnetic nanoparticle, to catalyze sulfite oxidation for the degradation of the metoprolol drug. The reaction mechanism was investigated by electron spin resonance, X-ray photoelectron spectroscopy, and radical quenching assay. The effects of pH, CuFe₂O₄, and sulfite dosages were also assessed. Results show that SO ₄ ^?? was the primary radical responsible for metoprolol degradation. Higher pHs induced more metoprolol degradation using CuFe₂O₄/sulfite. Moreover, CuFe₂O₄ remained morphologically intact and catalytically active after four batches of recycling. Overall, our findings show that CuFe₂O₄/sulfite can effectively degrade water contaminants in alkali pH and withhold catalyst activity after multiple reuses, therefore addressing the issues associated with homogeneous metal/sulfite systems.     

丙烯腈暴露对大鼠脑组织损伤及iNOS/p38 MAPK信号通路关键蛋白表达的影响

通过探究iNOS/p38 MAPK信号通路在丙烯腈(acrylonitrile,ACN)诱导脑组织损伤中的作用,为进一步研究ACN的神经毒性作用提供依据。选取50只SPF级健康成年雄性SD大鼠,随机分为5组,每组10只。适应性饲养一周后,以12.5、25.0、50.0 mg·kg~(-1)ACN对大鼠进行灌胃染毒,对照组给予玉米油,另设NAC组(300.0 mg·kg~(-1)NAC+50.0 mg·kg~(-1)ACN),1次·天~(-1),6天·周~(-1),共染毒13周。次日称重并处死大鼠,测定大鼠脑组织NO含量、总NOS水平及iNOS、p-p38和p38蛋白表达水平。结果显示,ACN各剂量组大鼠脑组织脏器系数与对照组比较均显著降低(P0.05),高剂量组大鼠脑脏器系数与NAC组比较降低(P0.05)。高剂量组NO含量和总NOS水平显著高于对照组,与NAC组比较,高剂量组NO含量降低(P0.05),总NOS水平升高(P0.05)。Western blot结果显示,ACN高剂量组大鼠脑组织iNOS、p-p38蛋白表达水平和p-p38/p38比值显著高于对照组和NAC组(P0.05)。ACN可激活iNOS/p38MAPK信号通路,这可能是ACN致大鼠脑组织损伤的机制之一。     

水生和陆生生物体中卤系阻燃剂的差异性富集研究:以鲶鱼和家鸽为例

分析了水生(鲶鱼)和陆生(家鸽)生物体中卤系阻燃剂(HFRs)的组成和浓度。鲶鱼中短链氯化石蜡(SCCPs)浓度均值为30 800 ng·g~(-1)lw(脂肪归一化浓度),是最主要的HFRs,然后依次是多溴联苯醚(PBDEs)(2 300 ng·g~(-1)lw)、四溴双酚A(TBBPA)(37 ng·g~(-1)lw)、六溴环十二烷(HBCD)(21 ng·g~(-1)lw)、德克隆(DP)(14 ng·g~(-1)lw)、十溴二苯乙烷(DBDPE)(7.1 ng·g~(-1)lw)和六溴苯(HBB)(6.2 ng·g~(-1)lw);而家鸽中PBDEs含量最高(17 000 ng·g~(-1)lw),其次是SCCPs(7 600 ng·g~(-1)lw)DP(1 600 ng·g~(-1)lw)DBDPE(14 ng·g~(-1)lw)HBB、TBBPA和HBCDs(未检出)。鲶鱼和家鸽HFRs组成比较发现,鲶鱼中具有较高百分含量的低溴代PBDE单体和较低的fanti值,而家鸽中具有较高百分含量的高溴代PBDE单体和较高的fanti值。实验结果初步表明,水生生物较多地富集水溶性较大的化合物,陆生生物则较多地富集疏水性较强的化合物。研究认为以上水生和陆生生物体中污染物的差异性富集现象可能与化合物因不同物理化学性质导致的不同环境迁移行为有关。     

超滤膜联合高级氧化技术深度处理综合工业污水的研究

采用超滤膜联合高级氧化技术对混合工业园区污水中难降解有机污染物、色度、总大肠菌等进行深度处理。结果表明:运行8周后悬浮物、COD、氨氮、总磷和色度的平均去除率分别为92%、90%、70%,63%和90%,总大肠菌去除率达100%。最终出水水质均可达到城市回用水水质标准。     

污水厂曝气节能智能优化控制系统

针对国内大部分污水厂现有曝气控制中存在着溶解氧浓度波动大、曝气量冗余大、曝气单元能耗高等问题,提出曝气节能智能优化系统,该系统通过获得A/O工艺实时的在线数据不断进行模拟计算,然后按照生化池进水的污染物负荷状况,以曝气能耗最小为目标函数来获取最优的DO设定值及其PI控制器的参数Kp、Ki。该智能优化系统在沥滘污水厂的实际应用情况表明:该系统在盫こ鏊实那榭鱿拢唤鎏岣吡讼低车目垢汉沙寤髂芰Γ苯档土?曝气能耗。     

低浓度生活污水处理工艺调试运行

介绍了绩溪污水处理厂在低浓度进水条件下的生物启动和调试运行,通过外加碳源虽然可以暂时缓解培养初期活性污泥增长缓慢的问题,但不是长期的运行方式。可以引入部分工业废水至生物处理系统,以提高进水有机底物浓度。但要特别注意避免冲击负荷对系统带来的破坏性影响,同时应根据实际情况灵活调整工艺参数。