简讯

聚合硫酸铁的生产新工艺 聚合硫酸铁(PFS)是近几年发展起来的一种无机高分子絮凝剂,主要用于饮用水和废水的净化处理。其生产方法多种多样,但都包括了氧化、水解和聚合等过程。若按氧化方式的不同来划分,主要包括直接氧化法和催化氧化法二大类。目前,国内外生产液体PFS普遍采用催化氧化法,主要选用亚硝酸     

高效净水剂聚合硫酸铁合成及性能研究

通过过氧化氢氧化、水解、聚合制备聚合硫酸铁,并对合成聚合硫酸铁的条件进行研究。将得到的产品用于模拟高岭土废水的处理,浊度去除率可达97％,用于污水处理厂总入水口废水的处理,COD去除率达到64％,并对其应用的最佳条件进行了研究。     

从硫铁矿矿渣中制备聚合硫酸铁

以硫铁矿矿渣为原料 ,按反浮选和选择性浸出原理除去杂质 ,在 1 0 0°C用硫酸浸得硫酸铁和硫酸亚铁混合液 ,并测定了 Fe2 + 和 Fe3 + 含量。同时对废铁屑经硫酸洗涤和纯碱洗涤后 ,把过量的废铁屑加入该混合液中 ,使整个溶液还原成硫酸亚铁溶液。采用氯酸钠氧化法 ,在 65°C经氧化、水解、聚合得聚合硫酸铁溶液 ,讨论了影响聚合反应的主要因素。对炼油厂废水进行处理 ,合成的聚合硫酸铁的处理效果明显优于市售三氯化铝     

丙烯酸工艺技术路线分析以及直氧法探究

丙烯酸广泛用于化工行业酯类聚合单体等原料.丙烯酸作为乙烯类单体在聚合反应中聚合速率较快,它的生产工艺方法很多,主要采用甘油等原料,生产工艺方法主要有丙烷脱氢氧化以及丙烯直接氧化两种工艺方法.本文通过对比不同的生产工艺路线,依据丙烯酸生产的现状、各主要企业的产能、装置运行情况,提出了直氧法生产丙烯酸的工艺现状以及改进,提...     

环氧丙烷生产工艺的发展现状

概述了国内外环氧丙烷生产工艺现状,目前已工业化的生产技术包括氯醇法、共氧化法、异丙苯氧化法、过氧化氢直接氧化法;总结了各方法的特点,并简单概况了环氧丙烷生产工艺的最新研究进展。     

聚合硫酸铁的制备、改性及应用研究进展

聚合硫酸铁（PFS）作为一种无机高分子混凝剂，较传统混凝剂具有更强的混凝和吸附能力，被广泛应用于饮用水、工业废水和生活污水的处理中。近年来，随着我国经济的快速发展和双碳理念的深入人心，混凝剂的市场需求量正在逐年增加。综述了制备聚合硫酸铁常用的催化氧化法、直接氧化法和生物氧化法3种方法，分析了常用催化剂和氧化剂的优缺点。通过分析聚合硫酸铁无机阴、阳离子改性和有机高分子改性等改性方法的最新研究进展，介绍了聚磷酸硫酸铁、聚合硫酸铁铝、聚合硫酸铁锌、钙化聚合硫酸铁、稀土镧聚合硫酸铁、聚合硫酸铁钛、聚硅酸硫酸铁钛等改性PFS产品。最后概述了聚合硫酸铁在水处理领域的应用，并对其未来的研究方向和发展前景进行了展望。     

用钛白废酸和废铁屑制备聚合硫酸铁试验研究

利用钛白废酸和废铁屑制备了无机高分子絮凝剂聚合硫酸铁。详细研究了聚合硫酸铁制备过程中各因素对亚铁氧化、三价铁水解和聚合等过程的影响。确定了制备聚合硫酸铁的最佳工艺条件为：(1)氧化过程：pH为1．5，氧化剂与亚铁的物质的量之比为0．3，氧化温度为60℃，氧化时间为3h；(2)聚合过程：硫酸根与全铁的浓度比为1．4，陈化时间为2h。     

利用工业废酸制备混凝剂试验研究

以钛白粉生产中的副产物硫酸亚铁和废硫酸为原料,在一定温度和压力下,经氧化、水解和聚合等过程制备混凝剂聚合硫酸铁(PFS),运用红外光谱法(IR)、X-射线衍射法(XRD)和透射电镜法(TEM)对制得的产品进行了表征。通过混凝实验考察了产品PFS对印染废水的处理效果,同时与市售PFS产品进行了对比,结果显示,自制PFS产品用于印染废水处理中,COD、色度和浊度均具有较高的去除效率,实现了废弃物资源化利用。     

高附加价值含氯中间体市场前景分析

一、氯乙酸氯乙酸的生产方法很多,主要有氯乙烯氧化法、氯乙酰氯水解法、乙烯酮氧化法、氯乙醇氧化法、三氯乙烯水解法,乙酸(醋酸)催化氧化法等。目前工业化的生产方法有三种,第一种是硫酸水解三氯乙烯法生产氯乙酸,该方法生产消耗定额偏高,工业流程长,成本较高,但能制得高纯度     

氯酸盐直接氧化法制备高浓度聚合铁

氯酸盐直接氧化法制备高浓度聚合铁史成武（安徽工学院基础部，合肥２３００６９）聚合硫酸铁（也称聚羟基硫酸铁、聚合铁、ＰＦＳ）是一种高效无机阳离子型高分子铁系絮凝剂。它在给排水作业中较之其他混凝剂愈来愈显示出较多的优越性。聚合硫酸铁的生产工艺很多，应用于...     

Electrogenerative formation of ferric ions in a sulfur dioxide–sulfuric acid solution; Graphite catalysed sulfur dioxide oxidation

The electrogenerative oxidation of ferrous ions in 3m sulfuric acid, containing sulfur dioxide and subsequent sulfur dioxide oxidation, were studied in connection with potential regenerable sulfur dioxide remediation processes. The presence of sulfur dioxide in the feed stream did not affect cell performance. Oxidation of sulfur dioxide in the electrogenerative reactor took place when high ferrous to ferric ion conversions were obtained. Low cost graphite and iron ions served as an effective mediating system for promoting electron transfer to sulfur dioxide in strong acid solutions. In contrast, the homogenous reaction between iron(iii) and sulfur dioxide is relatively slow. In a separate batch reactor, the heterogeneous iron(iii) and sulfur dioxide reaction was found to be graphite catalysed, accounting for sulfur dioxide conversion observed in the electrogenerative reactor. Ferrous ion presence should be minimized, because it inhibits the desired catalysed reaction.     

氯化钾镉钴合金电镀废水的组合处理方法

在pH为10~12的条件下,先用亚铁离子和钙离子共同沉淀氯化钾镉钴合金电镀和钝化混合废水中的氨三乙酸等羧酸配位剂,六价铬被亚铁离子还原成三价铬后与镉离子、钴离子等一同生成氢氧化物沉淀。再用二甲基二硫代氨基甲酸钠沉淀废水中残留的重金属离子,使其沉淀完全。最后用次氯酸钠氧化废水中的电镀添加剂,降低其化学需氧量(COD)。该方法成本低,处理结果可满足GB 21900-2008《电镀污染物排放标准》的“表3”要求。     

高分子铁盐絮凝剂制备及其应用研究

研究了以废铁屑和工业硫酸亚铁为原料,在常压和加热条件下,用氯酸钾作为氧化剂制取聚合硫酸铁(PFS)的工艺条件,并在PFS制备的基础上,合成了聚磷硫酸铁(PPFS)和聚氯硫酸铁(PFCS)。将所制备的聚铁用于污水处理实验,结果表明:用该方法制备的聚铁絮凝剂对实际水样具有较好的混凝处理效果,且制备工艺简单、速度快,从根本上消除了用NaNO_2催化氧化法制备聚铁对环境造成的二次污染。     

Electrogenerative oxidation of ferrous ions with graphite electrodes

Electrogenerative oxidation of ferrous ions in Fe²⁺/O₂ cells to regenerate ferric ions for further use is demonstrated and some results for a hybrid type laboratory-scale reactor are presented. The use of graphite particle, packed-bed anodes for ferrous oxidation with gas diffusion type cathodes for oxygen reduction enables these cells to produce ferric ions at moderate current densities and low cell voltages in sulphuric acid solutions. These cells which utilize the rapid electrochemical, ferrous oxidation rate on graphite catalytic electrodes without any need for an external power source have potential application in hydrometallurgical leaching systems as well as in sulphur dioxide cleanup processes which incorporate the use of ferric ions. Continuous feed stream operation under mild conditions is a special advantage.To whom correspondence should be addressed.     

Influence of process variables on biooxidation of ferrous sulfate by an indigenous Acidithiobacillus ferrooxidans. Part II: Bioreactor experiments

The oxidation of ferrous iron in solution using Acidithiobacillus ferrooxidans has industrial applications in the regeneration of ferric iron as an oxidant agent for the removal of hydrogen sulfide from waste gases, desulphurization of coal, leaching of non-ferrous metallic sulfides and treatment of acid mine drainage. The aim of this attempt was to increase the biooxidation rate of ferrous sulfate by using immobilized cells. Rate of ferrous iron oxidation was determined in a packed-bed reactor configuration with low density polyethylene (LDPE) particles as support material in order to find the most practical system for scale-up. The present work studies the influence of basic parameters on the ferrous iron biooxidation process using an indigenous iron-oxidizing microorganism, namely A. ferrooxidans, in a 2 L packed-bed bioreactor. Effects of several process variables such as initial pH, temperature, dilution rate, initial concentrations of ferrous and ferric ions on oxidation of ferrous sulfate were investigated. Experimental results indicate that in the temperature range of 31–34 °C the biooxidation of ferrous ions to ferric ions could be resulted efficiently. A pH range of 2–2.2 was optimum for the growth of the culture and effective bacterial activity for oxidation of ferrous ions to ferric ions. The highest oxidation rate of 2.9 g Fe²⁺ L⁻¹ h⁻¹ was obtained using a culture initially containing 25 g L⁻¹ Fe⁺² at the dilution rate of 0.4 h⁻¹. This rate is very high compared to that achieved in other bioreactors found in the literature. In addition the biooxidation of Fe²⁺ to Fe³⁺ conversion could be achieved effectively in the presence of the Fe³⁺ in the concentration range of 0.1–0.7 g/L.     

Catalytic wet oxidation of phenol with homogeneous iron salts

The catalytic wet oxidation of phenol has been investigated in a 1 L semi‐batch reactor in the presence of both ferrous and ferric salts. Oxidation reactions follow first‐order kinetics with respect to phenol and half‐order kinetics with respect to dissolved oxygen. The activation energy for the reaction was 44.5 and 48.3 kJ mol^?1 for runs employing Fe³⁺ and Fe²⁺, respectively. Rate constants and induction periods were also similar for both catalysts. This result could be explained by analysing the evolution of iron during the oxidation process. For pH > 2, Fe²⁺ was rapidly oxidized under reaction conditions to Fe³⁺, resulting in a unique catalytic redox system Fe²⁺/Fe³⁺. It was also shown that if pH < 2 the dissolved oxygen was unable to oxidize ferrous ion, resulting in a much slower oxidation rate of phenol. The absence of a redox pair resulted in a complete lack of catalytic activity of the dissolved iron salt. Copyright © 2005 Society of Chemical Industry     

氧化-混凝工艺处理碱性含砷废水的试验研究

研究了用氧化与混凝组合工艺处理某锑冶炼厂排放的碱性含砷废水。研究结果表明,聚合硫酸铁较三氯化铁、硫酸亚铁对原水中砷的去除效果好;用氧化与混凝组合工艺较单纯用混凝工艺对砷的去除率高：双氧水、次氯酸钠这两种氧化剂中采用次氯酸钠氧化对原水中砷的去除效果及处理成本最佳。     

Bio‐oxidation of ferrous ions by Acidithioobacillus ferrooxidans in a monolithic bioreactor

BACKGROUND: The bio‐oxidation of ferrous iron is a potential industrial process in the regeneration of ferric iron and the removal of H₂S in combustible gases. Bio‐oxidation of ferrous iron may be an alternative method of producing ferric sulfate, which is a reagent used for removal of H₂S from biogas, tail gas and in the pulp and paper industry. For practical use of this process, this study evaluated the optimal pH and initial ferric concentration. pH control looks like a key factor as it acts both on growth rate and on solubility of materials in the system. RESULTS: Process variables such as pH and amount of initial ferrous ions on oxidation by A. ferrooxidans and the effects of process variables dilution rate, initial concentrations of ferrous on oxidation of ferrous sulfate in the packed bed bioreactor were investigated. The optimum range of pH for the maximum growth of cells and effective bio‐oxidation of ferrous sulfate varied from 1.4 to 1.8. The maximum bio‐oxidation rate achieved was 0.3 g L^?1 h^?1 in a culture initially containing 19.5 g L^?1 Fe²⁺ in the batch system. A maximum Fe²⁺ oxidation rate of 6.7 g L^?1 h^?1 was achieved at the dilution rate of 2 h^?1, while no obvious precipitate was detected in the bioreactor. All experiments were carried out in shake flasks at 30 °C. CONCLUSION: The monolithic particles investigated in this study were found to be very suitable material for A. ferrooxidans immobilization for ferrous oxidation mainly because of its advantages over other commonly used substrates. In the monolithic bioreactor, the bio‐oxidation rate was 6.7 g L^?1 h^?1 and 7 g L^?1 h^?1 for 3.5 g L^?1 and 6 g L^?1 of initial ferrous concentration, respectively. For higher initial concentrations 16 g L^?1 and 21.3 g L^?1, bio‐oxidation rate were 0.9 g L^?1 h^?1 and 0.55 g L^?1 h^?1, respectively. Copyright © 2008 Society of Chemical Industry     

盐酸法钛白粉新工艺副产氯化亚铁制备四氧化三铁

探索了一种以盐酸法钛白粉新工艺副产氯化亚铁为原料制备四氧化三铁磁粉的放大试验工艺,把副产危废氯化亚铁制备成用途广泛的四氧化三铁磁粉,实现资源的综合利用。研究结果表明：选用氧化钙为沉淀剂与氯化亚铁反应得到氢氧化亚铁,在分散剂辅助作用下通入空气使氢氧化亚铁被氧化成三价氢氧化铁,控制氧化钙及分散剂加料时间间隔为1.5 h、氧化温度为80℃、氧化时间为8.5 h,将氢氧化铁与氢氧化亚铁以物质的量比为2∶1均匀混合,通过正压分离得到固体,控制分离前pH为6.5,最后通过烘干、研磨等后处理得到四氧化三铁磁粉。进行50 kg级别放大试验得到四氧化三铁产品,收率达到97%。该工艺将副产危废转化为有一定经济效益的产品,进一步完善了盐酸法钛白粉新工艺。