Pipes serving for water distribution system for different years in northern city,were chosen as objectives for study.The shape and component of corrosion scales were measured,and formation mechanism of corrosion was also analyzed.The corrosion mechanism of pipes was studied on the sides of electrochemistry and microbe.The solution to eliminate corrosion scales in water distribution system was also proposed.The results show that the specific surface areas of five corrosion scales are between 41.35 and 132.3 m2/g and the dimension of corrosion scales enlarge with the increase of serving age,which could induce the decrease of water flow cross-section.
针对废水两相厌氧处理系统中产酸相反应器的乙醇型发酵启动速度较慢,污泥易流失的不足,本文采用在产酸相反应器中接种厌氧颗粒污泥,同时控制启动容积负荷、负荷提高幅度、碱度等运行参数,对反应器乙醇型发酵的形成情况进行考察.通过监测液相末端产物、pH、ORP、酸化度等指标来考察反应器的运行情况,结果表明:反应器在34 d内完成由混合酸发酵-丁酸型发酵-乙醇型发酵的演替过程.启动结束时,乙醇+乙酸质量质量浓度之和占液相末端产物总量的75.9%以上;pH值稳定在4.1～4.3;ORP值稳定在-230～-250 mV;接种的厌氧颗粒污泥性质发生明显变化,其表观颜色逐渐由黑色和灰黑色变为土黄色和黄褐色,粒径明显减小,多在0.50～1.25 mm.
This paper reports a simple and efficient chemical method to decorate multi-walled carbon nano-tubes(MWCNTs) with iron oxide nanoparticles. The TEM, FTIR, Raman and UV analysis demonstrate that iron oxide nanoparticles were well deposited on the outer walls of MWCNTs. The size of the nanoparticles ranges from 30 to 50 nm. The sorption property of MWCNTs/Fe3O4 composites for the removal of 2,4-dichlorophenol(2,4-DCP) and Cu2+ ions from aqueous solution was explored. The results present that MWCNTs decorated with Fe3O4 possessed higher sorption capability for removing 2,4-DCP and Cu2+ ions, which favour the highly potential applications for pollutants removal from water.
