两种国标方法测定大气中二氧化硫的比较研究

国标方法中环境空气中二氧化硫的测定方法主要有甲醛吸收-副玫瑰苯胺分光光度法和四氯汞盐吸收-副玫瑰苯胺分光光度法.对国标方法中两种副玫瑰苯胺分光光度法测定环境空气中二氧化硫所用的两种吸收液(四氯汞钾、甲醛)的吸收效果及方法的准确性、精密度等条件作了比较试验.结果表明,采用甲醛溶液作吸收液与四氯汞钾溶液作吸收液相比,吸收效果、精密度和准确度更好,测定的检出限低.用甲醛溶液做吸收液,除了上述优点外,还可避免使用大量的汞盐,有利于环境保护.     

气相色谱法测定环境空气中异丙醇研究

建立了用气相色谱法测定环境空气中异丙醇的方法。环境空气中异丙醇以蒸馏水吸收,用(DB-624)弹性石英毛细管柱分离,直接进样分析,氢火焰离子化检测器检测。本方法以时间定性,峰面积定量,对实际样品进行分析,其异丙醇加标回收率为94.9%~104.5%,当采样体积为40 L,异丙醇最低检出质量浓度为0.05mg/m3。本方法前处理简便,分离度好干扰少,分析灵敏度高,不使用有机试剂以减少环境污染,满足环境分析要求。     

HSE管理体系在中海油深圳分公司的应用研究

中海油深圳分公司,是中国海洋石油上游的重要组成部分,也是国内最早建立完善HSE管理体系的企业之一.在HSE管理体系建设方面,体系框架包括了核心理念、HSE管理政策、HSE管理目标、相关体系文件、管理程序、应急计划及HSE管理的保障机制等构成部分.文章运用SWOT分析等多种手段对中海油深圳分公司HSE管理的现状进行了分析,总结了公司在HSE管理执行过程中的先进方法并阐述了积极作用和意义.     

沙蚕生物扰动对河口沉积物中菲释放的影响

生物扰动是一个重要沉积物-水界面过程,影响沉积物中污染物的归趋.为了探究生物扰动对沉积物中多环芳烃释放的影响.在室内进行30 d的沙蚕生物扰动对河口沉积物中菲释放的影响实验.结果表明,相对于对照,生物扰动提高水体中颗粒态菲达到2.96~10.35倍,溶解态菲为9.55~17.44倍.由此可见,沙蚕的生物扰动极大的促进了沉积物中菲向水体释放.在生物扰动处理中,两种形态的菲所占比例不同,其中溶解态菲占释放总量的80%以上,表明沙蚕的生物扰动主要是提高水体中溶解态菲.由于溶解态菲能被生物所利用,通过食物链威胁人类健康.因此,沙蚕生物扰动造成的沉积物中的污染物释放具有潜在的生态风险.     

Graphene-supported nanoscale zero-valent iron：Removal of phosphorus from aqueous solution and mechanistic study

Excess phosphorus from non-point pollution sources is one of the key factors causing eutrophication in many lakes in China,so finding a cost-effective method to remove phosphorus from non-point pollution sources is very important for the health of the aqueous environment. Graphene was selected to support nanoscale zero-valent iron(nZVI)for phosphorus removal from synthetic rainwater runoff in this article. Compared with nZVI supported on other porous materials,graphene-supported nZVI(G-nZVI) could remove phosphorus more efficiently. The amount of nZVI in G-nZVI was an important factor in the removal of phosphorus by G-nZVI,and G-nZVI with 20 wt.% nZVI(20% G-nZVI)could remove phosphorus most efficiently. The nZVI was very stable and could disperse very well on graphene,as characterized by transmission electron microscopy(TEM) and scanning electron microscopy(SEM). X-ray photoelectron spectroscopy(XPS),Fourier Transform infrared spectroscopy(FT-IR) and Raman spectroscopy were used to elucidate the reaction process,and the results indicated that Fe-O-P was formed after phosphorus was adsorbed by G-nZVI. The results obtained from X-ray diffraction(XRD) indicated that the reaction product between nZVI supported on graphene and phosphorus was Fe3(PO4)2·8H2O(Vivianite). It was confirmed that the specific reaction mechanism for the removal of phosphorus with nZVI or G-nZVI was mainly due to chemical reaction between nZVI and phosphorus.     

Effects of extracellular polymeric substances on aerobic granulation in sequencing batch reactors

The effects of extracellular polymeric substances on aerobic granulation in sequencing batch reactors were investigated by evaluating the content and compositions of extracellular polymeric substances, and the relationship between extracellular polymeric substances composition and surface properties of glucose-fed aerobic granules. The results showed that extracellular polymeric substances could affect surface properties of cells, such as surface charge and hydrophobicity, enhance polymeric interaction and promote aerobic granulation. Moreover, extracellular polymeric substances were produced mainly in the exponential phase, and served as carbon and energy source in starvation phase during granulation process, thus regulating the growth of bacteria in the interior and exterior of granules, and maintaining the integrality of granules.     

基于HR/CFD技术的城市汽车尾气扩散规律研究

为研究城市空间结构对汽车尾气扩散规律,根据高分辨率遥感影像建立了某城市核心区域几何模型。以当地常年气象风向作为重要的边界条件之一,应用CFD多相流技术,模拟了十字交叉口车辆队列怠速等候35,45,55 s时的尾气扩散过程,并对45 s时4个监测点的体积分数进行了实测,最后,通过建筑高度优化,降低了该区域的尾气含量。以上研究结果表明:在空间狭小区域,近地空间CO体积分数达1.0×10-7,与研究域平均体积分数相差100倍以上,说明城市空间结构对尾气扩散影响较大,仿真所揭示的规律与实测吻合。建筑设计时应结合当地气象风向和风速,应设计一定的建筑高度梯度,可以促使污浊气体迅速扩散至远地空间。     

Investigation and modeling of solar UV-induced chlorine decay in disinfection contact basins at full-scale wastewater treatment plants

Residual chlorine loss due to UV sunlight in the chlorine disinfection contact basins (DCBs) was investigated at two full-scale wastewater treatment plants (WWTPs). Chlorine decay due to solar UV-induced photochemical reaction was found to be significant and had diurnal and seasonal variations. The total chlorine loss due to sunlight ranged from 19 to 26% of the total chlorine chemical use at the two plants studied. Covering chlorine contact basins led to more stable chlorine demand regardless of the diurnal and seasonal sunlight intensity. Therefore, covering chlorine contact basins offers more stable, or accurate, chlorine dosage and effluent residual control and requires less effort by plant operators. A mathematical model was developed to calculate the amount of UV-induced chlorine decay. The model developed can be used to estimate the UV-induced chlorine decay rate and total chlorine loss due to sunlight at WWTPs with various basin configurations, flowrates, chlorine dosages, and geographical locations. The model results allow the capital cost of covering needs to be assessed against the chlorine chemical cost savings.