Nitrogen and phosphorus removal from domestic strength synthetic wastewater using an alternating pumped flow sequencing batch biofilm reactor

Nutrient removal from domestic strength synthetic wastewater by an alternating pumped flow sequencing batch biofilm reactor (APFSBBR) was investigated in this laboratory study. The APFSBBR comprised two reactor tanks (Reactors 1 and 2) with two identical biofilm modules of vertical tubular plastic media with a high specific surface area, one in each tank. The APFSBBR was operated in cycles of four phases: fill, anaerobic, aerobic, and draw. During the fill phase, Reactor 1 was half-filled with domestic strength synthetic wastewater. During the subsequent anaerobic phase, most of the phosphorus release took place from the submerged biofilm in this reactor. In the aerobic phase, the wastewater was circulated by pumps between Reactors 1 and 2, resulting in denitrification at the start of the aerobic phase due to low oxygen concentrations, followed by nitrification and luxury uptake of phosphorus when oxygen concentrations increased. During the draw phase, Reactor 2 was half-emptied of the treated water. At the chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) loading rates on the total biofilm area of 3.20 g COD, 0.33 g TN, and 0.06 g TP m(-2) d(-1), the removal efficiencies were 97, 85, and 92% for COD, TN, and TP, respectively.     

干旱绿洲地区土地利用总体规划修编中的几个问题

提出了绿洲土地持续利用应遵循的４条原则：系统协调原则、区域稳定原则、动态平衡原则和用养结合原则,在此基础上讨论了适应绿洲土地利用总体规划修编的４种模式     

深软土场地上高层住宅的地震安全性问题

现代城市建设中高层住宅建在深软土场地上是难以完全避免的。因深软土场地上的高层住宅易遭震害,地震安全性问题应予充分重视。建议将高层住宅建设工程列入需作“工程场地地震安全性评价”之列,高层住宅的防震减灾宜从城市建设规划着手,针对高层住宅易遭震害的动力学特性等采取相应对策。     

增敏碘量法同时测定微量Mn(Ⅱ)、 Mn(Ⅶ)、 Cr(Ⅲ)、 Cr(Ⅵ)

介绍了用增敏碘量法同时测定微量的Ｍｎ（Ⅱ）、Ｍｎ（Ⅶ）、Ｃｒ（Ⅲ）和Ｃｒ（Ⅵ）。将样品中的Ｍｎ（Ⅶ）和Ｃｒ（Ⅵ）用Ｎａ２ＳＯ３预先还原,在ｐＨ为３．０的醋酸盐介质中对Ｍｎ（Ⅱ）和Ｃｒ（Ⅲ）用过量ＫＩＯ４氧化（当用Ｈ２Ｐ２Ｏ２－７掩蔽Ｃｒ（Ⅲ）时,只有Ｍｎ（Ⅱ）被氧化）,过剩的ＩＯ－４用钼酸盐掩蔽,加入ＫＩ后,以Ｎａ２Ｓ２Ｏ３滴定游离出的Ｉ２。此法对Ｍｎ的测定范围为２９～１４７０６μｇ／Ｌ,相对标准偏差为０．３１％～１．１８％;对Ｃｒ的测定范围为５９～１０２９４μｇ／Ｌ,相对标准偏差为０．３６％～１．１２％。此法与常规滴定法测定Ｍｎ和Ｃｒ相比,分别可增敏２０倍和１２倍     

维护职工安全健康合法权益是工会的神圣职责

保护劳动者在生产过程中的生命安全与健康,是经济建设的保障条件,也是社会发展的目标之一。党和国家十分重视安全生产工作,江泽民等党中央和国务院的领导同志对安全生产王作多次作出重要指示,强调了在社会主义市场经济条件下加强安全生产工作的重要意义,明确提出了做好这项工作的要求。按照企业负责、行业管理、国家监察和群众监督的安全生产管理体制,工会组织在监督企业安全生产和维护职工安全健康权益方面负有重要职     

工业振动危害和控制研究观念的进展

论述了对产生振动的机械设备实施隔振,不仅能减少或消除振动对振源周围的操作者、精密仪器设备和建筑带来的危害和影响,而且能直接或间接带来很大的经济效益;从理论上和实践上重点论述了隔振能延长机械设备精密部件和其所带模具的寿命;提出了隔振当量经济效益概念。这些探讨和研究工作对隔振决策有重要的参考意义     

炼化设备检维修遗留物风险评估及安全对策研究

分析了炼化企业设备检维修后，设备顶部、旋梯、平台等处遗留物的现状及可能对生产设备、人员产生的伤害。针对检维修遗留物性质、产生伤害的可能性建立风险评价方法并提出安全对策。     

Influence of phosphate on deposition and detachment of TiO2 nanoparticles in soil

We examined influence of phosphate on transport of TiO₂ NPs in soil. Deposition was reduced at higher pH and by adsorption of phosphate in soil. Release was more for NPs initially deposited at higher pH. Release was more for NPs initially deposited in the presence of phosphate. Surface roughness and charge heterogeneity play a role in the deposition/ release. The widespread use of TiO₂ nanoparticles (NPs) makes inevitable their release into the soil. Phosphate is also widespread within soil, and is likely copresent with TiO₂ NPs. However, the influence of phosphate on deposition/release— and thereby on transport— of TiO₂ NPs in soil is yet to be elucidated. In this study we conducted saturated column experiments to systematically examine the transport of TiO₂ NPs in soil amended with phosphate at different ionic strengths (ISs) (1, 10, 100 mmol/L NaCl) and pHs (4 and 9). Results show that the deposition of TiO₂ NPs decreased with decreasing IS, increasing pH, and when soil absorbed phosphate. These observations are qualitatively in agreement with Derjaguin-Landau-Verwey-Overbeek (DLVO) interaction energy calculations, because the repulsive energy barrier is larger and secondary minimum depth is smaller at a lower IS, higher pH, and in the presence of phosphate. Accordingly, both primary- and secondary-minimum deposition were inhibited. Interestingly, although the deposition was less at higher pH and in the presence of phosphate, the subsequent spontaneous detachment and detachment by reduction of solution IS in these cases were greater. In addition, the presence of phosphate in the solution can cause a small quantity of attached TiO₂ NPs to detach, even without perturbations of physical and chemical conditions. Our study was the first to investigate the influence of phosphate on detachment of TiO₂ NPs and the results have important implication for accurate prediction of fate and transport of TiO₂ NPs in subsurface environments.     

电炉烟气热管余热回收的除尘系统设计

电炉烟气余热回收是近几年最新发展的节能减排措施。介绍目前应用的热管余热回收装置的基本结构、工作原理及具有的优势,该装置已经得到成功应用,特别适合用于VOD冶炼特钢工艺中替代蒸汽锅炉。     

废旧沥青混合料的环境影响分析

分析了废旧沥青混合料中沥青的毒性及对环境的直接危害,以及当前沥青混合料不同处理方式对环境的影响,并对废弃这些沥青混合料而开采使用新材料带来的潜在环境破坏进行了科学的分析,提出了具体解决的方法。