混凝剂的水溶液形态与流动电流的相关特性分析

混凝剂具有多种溶液形态，每种形态对混凝过程的作用不同，因而对流动电流的影响也不同，本通过实验及理论分析，阐述了一般水处理条件下的流动电流检测器（ＳＣＤ）对混凝剂的检测原理，分析了水中混凝剂形态改变过程中流动电流的变化特征，探讨了ＳＣＤ对不同形态混凝剂的响应灵敏度，结果表明，中性条件下铝盐的混凝过程以及三价铁阳离子对流流具有较为灵敏的正增值效果。     

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.     

危险化学品活性反应危害及混配危险的规则研究(Ⅸ)

胺 活性特点: 胺可以看作氨分子中的氢原子被烃基取代而生成的化合物.胺中氮原子的电子构型是1S22S22P3,氮在氨和胺分子中是不等性的SP3杂化状态,其中3个杂化轨道与氢原子或烃基的碳原子形成3个σ键,第4个杂化轨道中还有一对未共用的电子,即(RH2N:).由于氮原子上有一孤电子对能与质子结合,呈现出胺的碱性,而氨分子中的氢原子被烷基取代后,连接在氮原子上的烷基是供电子性基团,可使胺离子正电荷分散而稳定.铵正离子愈稳定说明胺的碱性愈强,所以脂肪胺的碱性比氨强,与酸接触会生成盐;而芳香胺的碱性比脂肪胺和氨都弱,这是由于芳胺中的氮原子上的孤电子对与苯环的π电子组成共轭体系,产生了电子的离域,使氮原子上的孤电子对向苯环离域,铵离子正电荷更加集中,这样氮原子上的电荷密度减少,接受质子的能力降低,因此碱性减弱.在芳香胺中,氮原子上连的苯环愈多,其孤电子对向苯环离域愈多,则碱性随之降低,只有在与强酸作用时生成盐,且生成的盐在水溶液中完全水解.三苯胺已接近中性,即使和强酸也不能生成盐.     

水和废水中2,4—滴,2,4—二氯酚,2,4,6—三氯酚的测定

用Ｕｌｔｒａ－２，３２０μｍ柱分离２，４－滴，２，４－二氯酚肽２，４，６－三氯酚，保证了检测结果有足够的精确度，用直接进水样技术而不必处理水样，使检测结果趋精确。     

pH平均值计算方法浅析

通过理论计算和实验对比，对五种pH平均值计算方法进行分析，表明对单一稳定体系进行多次测量的均值宜直接采用各pH测定值进行算术平均，而对于其它pH值极差较大或既有酸又有碱的样本，如天然降水，则应采用酸碱中和原理同时考虑水的电离的计算方法。     

从水溶液中分离回收醋酸方法的评述

评述了从水溶液中分离回收醋酸的普通精馏法、共沸精馏法、酯化法和溶剂萃取法，具体分析了各种方法 特点及适用范围。建议在工业上对较高浓度的醋酸用低沸点溶剂萃取－共沸精馏联合法，对低浓度醋酸溶液采用有机胺溶剂萃取法进行分离。     

改变垫水层沸点的薄层睛扬沸实验研究

扬沸是油池火灾的一种特殊现象,燃料和垫水层交界面的过热温度和沸腾状态是决定扬沸是否发生以及发生时间的最主要因素,过热温度由沸点决定.在垫水层中添加氯化钠能够改变垫水层的沸点,从而改变交界面的过热温度.在垫水层添加氯化钠使其成为饱和氯化钠水溶液,对此条件下的油池火燃烧进行实验探究,以验证前人关于扬沸临界条件的研究结果,并...     

碳酸锶生产废水的处理方法

该发明涉及一种碳酸锶生产废水的处理方法。过程为：废水用质量分数为25％～50％的H2O2溶液与质量分数为0．01％～5．00％的市售聚丙烯酰胺絮凝剂的水溶液澄清、再用质量分数为25％～50％的H2O2溶液脱硫、然后加入锰的彰和铁的氧化物分解。采用该发明的碳酸锶生产废水处理方法，出水中杂质含量少，可循环利用于碳酸锶生产过程的硫化锶浸取工段，对产品碳酸锶质量的改善有利；     

Photochemical degradation of nonylphenol in aqueous solution：The impact of pH and hydroxyl radical promoters

The degradation of nonylphenol (NP) in aqueous solution with UV, H₂O₂/UV, and Fenton/photo-Fenton processes was studied. The efficacy of direct and hydrogen peroxide photolysis proved to be dependent on the pH value. The addition of H₂O₂ to UV treatment improved NP degradation. The application of UV photolysis and the H₂O₂/UV system at pH 7 resulted in low pseudo first-order rate constants at 10^-4 sec^-1. In the experiments at elevated pH values the pseudo-first order rate constants increased to 10^-3 sec^-1. The efficacy of the Fenton process was lower in comparison with UV and hydrogen peroxide photolysis. The addition of UV irradiation to the H₂O₂/Fe²⁺ system substantially improved NP degradation efficacy. In terms of performance, the photo-Fenton process was similar to the H₂O₂/UV process. The most favourable process for complete nonylphenol degradation considering both operational cost and treatment efficacy was H₂O₂/UV at pH 11 and 250 mol/L H₂O₂.     

水体中亚硝酸盐的光降解

一定浓度的亚硝酸盐溶液经太阳光模拟器照射一定时间后,观测溶液中亚硝酸盐的含量变化.改变溶液条件（介质、pH）和光照条件（时间、光强）等实验条件,同时进行黑暗对照实验,探求影响亚硝酸盐光解的因素和规律.结果表明,在光照的8 h内,时间越长亚硝酸盐的降解率越大,基本符合一级反应动力学曲线;光照强度越大亚硝酸盐的降解程度越大...