酸浸法提取煤矸石中Al2O3的研究

煤矸石是主要的煤系固体废物,其中Al2O3质量分数约占35％左右.以某煤矿的煤矸石为原料,通过单因素实验比较盐酸和硫酸对Al2O3的浸取率,研究各因素对Al2O3浸取率的影响,确定浸取煤矸石中Al2O3的最佳酸浸介质为硫酸.利用正交实验确定酸浸取的最佳条件为:液固比(酸溶液体积与煤矸石样品质量比)15 mL/g、硫酸摩尔浓度3 mol/L、浸取时间120min、助样比(助溶剂与煤矸石样品质量比)0.20,在此条件下硫酸对煤矸石中A12O3的浸取率可达79.6％.     

炼铜烟灰制取高纯度硫酸锌

采用炼钢烟灰制取高纯度硫酸锌,研究了制取条件对收率和产品质量的影响,试验结果表明,控制适宜的酸浸条件,锌浸取率≥９８％,铁浸取率可控制在０．０２％以下,当酸浸工艺条件液固比为３：１,温度８０－９０℃,硫酸加入量３９ｇ／Ｌ（酸浸液）滴酸时间１．５ｈ浸取时间２ｈ,再用空气和过氧化氢氧化除去溶液中的铁,产品中硫酸锌含量≥９９％,铁含量可降至０．５ｍｇ／Ｌ以下。     

常压硫酸浸闪锌矿降低含硫化合物气体排放量的研究

研究了在常压、不需通氧或空气的条件下用硫酸浸取铁闪锌矿制硫酸锌过程中硫化物气体污染物的控制条件。试验结果表明，在硫酸浓度２０％￣４０％，浸取温度１１０℃￣１３０℃，固液比１：５￣１：７，以及强烈搅拌的条件下，浸取过程中Ｈ２Ｓ和ＳＯ２排放量最低，浸以２ｈ，锌的一次浸取率在９２％以上，闪锌矿中的硫绝大部分转变为单质硫。     

用钛白废酸和副产锌泥制备活性氧化锌

以次硫酸氢钠甲醛副产锌泥和钛白废酸为原料,经高剪切乳化、酸浸、锌粉置换、除杂、碱锌合成等工艺制得碱式碳酸锌,再经过滤、洗涤、干燥、煅烧制备活性氧化锌。考察了浸取工艺液固比(硫酸与副产锌泥的质量比)和硫酸质量分数对锌浸出率的影响,以及煅烧温度和时间对活性氧化锌质量的影响。实验结果表明,锌泥酸浸工艺的最佳液固比4,硫酸质量分数30%,在此工艺条件下,锌浸出率达95%。活性氧化锌的最佳煅烧温度为600℃,煅烧时间为240 min,在此条件下测定产品质量,氧化锌质量分数大于96%,比表面积大于50 m2/g,堆积密度小于0.35 g/m L。     

电镀锌泥饼的酸浸条件对锌浸出率的影响

研究了含锌泥饼的浸出条件。试验结果表明，适宜的酸浸条件：浸取液终点pH值为5左右；液固化（3：1）－（4：1）；分段加酸时间为2h；搅拌速度为100－200r/min，在上述条件下用硫酸溶液进行常温浸取，锌浸出率可达98％，铁浸出率小于1％。     

热镀锌厂酸洗废水及锌灰中锌回收

分别采用蒸酸法、氨络合法和硫化沉淀法分离回收热镀锌厂酸洗废水及锌灰中锌铁。分别考察了酸洗废水中盐酸的逸出特性和氨浸法回收蒸馏渣中锌的效果；利用酸洗废水的酸度浸取锌灰中的锌并用氨络合法分离酸浸出液中锌铁；利用硫化物不同溶度积选择性沉淀酸浸出液中的锌，考察了Na2S加入量、曝气时间、反应溶液pH和反应时间的影响。研究结果表明硫酸的加入能提高盐酸的蒸发率但效果不明显，氨络合法难于有效分离锌铁，但硫化物沉淀法可较好地分离锌铁，铁回收率可达97．12％，锌沉淀率达到99．99％，所得沉淀物中ZnS纯度为68．51％。     

电解锰渣中锰的浸出条件及特征

采用水洗-酸解法回收电解锰渣中锰,探讨了清水量、酸量以及温度在不同阶段对锰浸(洗)出条件的影响,分析了回收锰的主要因素及浸出特征。实验结果表明,50 g电解锰渣经m渣∶m水=1∶10的清水水洗后,采用10%的硫酸在70℃的水浴温度下酸解2 h,Mn2+浸出量为1.673 g,回收率达到97.3%,而温度和酸度对锰离子的浸出影响明显,酸度调控可有效分离酸浸锰液中金属成分,为减少电解锰渣环境污染的同时,实现电解锰渣资源化利用。     

集成膜法回收钛白废酸中硫酸

对扩散渗析回收钛白废酸中硫酸与减压膜蒸馏联合浓缩废酸进行了实验研究。结果表明,扩散渗析的酸回收率、回收酸浓度和亚铁泄漏率随料液流量的增大而减小,而酸渗析速度及酸对硫酸亚铁的分离系数却随之增大;随水料比的增大,酸回收率、酸渗析速率和亚铁泄漏率增大,回收酸浓度及酸对硫酸亚铁的分离系数减小;在选定实验条件下,硫酸浓度为1.92 mol/L的钛白废酸,先经扩散渗析进行酸盐分离,然后经减压膜蒸馏浓缩,可得到硫酸质量百分浓度为65%以上的浓缩废酸,达到了返回钛白生产使用的要求。     

电子废弃物的预处理技术

主要探讨硝酸-硫酸这一混酸体系溶解电子废弃物的条件。试验表明：在60℃下，1．23mol／L硝酸和3．22mol／L．硫酸组成的混酸体系与电子废弃物在机械搅拌下反应2h，就可使得电子废弃物的溶解率达到93％以上，铜的浸出率达到99％以上。     

煤矸石中氧化铝溶出的实验研究

煤矸石是主要的煤系固废,其中氧化铝的含量占到25%左右,又是一种可以利用的资源.本实验以山西潞安煤矿的煤矸石为原料,采用正交试验的方法,研究了盐酸作为酸浸介质浸取煤矸石中氧化铝.主要影响因素为煅烧温度、酸量、固液比及酸浸时间,最佳工艺条件为:煅烧温度为650℃,酸量为225mL(按照煤矸石中氧化铝和盐酸反应的摩尔比为1:6计)、固液比为1:3、酸浸时间为3 h,单因素重复试验结果和正交实验的结果相符,在最佳条件下,氧化铝的溶出实验验证结果表明,三氧化二铝溶出率为71.49%.本研究对实现煤矸石的资源化综合利用具有重要的意义.     

营养成分对Fe2+生物氧化的影响

在29℃和160 r/min条件下,以广东云浮矿山酸性废水为种源,采用9K培养基,经过富集培养得到氧化亚铁硫杆菌A.f.a。利用分批摇床实验,研究了在A.f.a作用下,溶液初始NH4+-N、PO34--P、Mg2+、Ca2+和Cu2+等基本营养成分对Fe2+生物氧化的影响。结果显示,随着NH4+-N、PO34--P、Ca2+或Cu2+离子浓度增加,Fe2+生物氧化率都先增大后降低,各离子最佳浓度分别为84.8、35.6、2.4和254.5 mg/L;Fe2+生物氧化率随着Mg2+浓度的增加逐渐增大,并趋于稳定,其限制浓度为88.8 mg/L。上述结果可用于控制营养条件促进Fe2+的生物氧化。     

pH dependence of ferrous sorption onto two smectite clays

This work examines the abilities of two smectite minerals (SWa-1 and Wyoming montmorillonite) to adsorb ferrous iron at concentrations from 0.037 mM (2 ppm) to 2.5 mM (240 ppm) over a range of pHs from 4.0 to 8.0. Both sorption isotherm and sorption edge data are presented. Ferrous sorption (Fe(aq)2+ = 0.1 mM) to both SWa-1 and Wyoming montmorillonite over the pH range 4.0-6.75 is relatively constant at approximately 1000 l kg(-1) for both minerals. Sorption in this pH range is attributed to the cation exchange capacity of the clay along the basal surfaces. At pH values above 6.75 the amount of ferrous iron sorbed increases dramatically. At pH 8, sorption (Fe(aq)+ = 0.1 mM) reaches 6600 l kg(-1) and 8000 l kg(-1) for Swa-1 and Wyoming montmorillonite respectively. This is attributed to the specific interaction between ferrous ions and surface sites along mineral edges. The overriding geochemical implication is that in reduced sediments containing more than a few percent clay, the pool of sorbed ferrous iron is vast. This pool of reduced iron is both redox labile and bio-available and is not readily indicated by simple measurement of dissolved Fe2+.     

Photoelectro-Fenton mineralization of phenol through optimization of ferrous regeneration

The degradation of phenol in acidic solution at pH 3 has been investigated under various photo- and electrochemical conditions. A laboratory-scale reactor on which were mounted net electrodes (RuO₂/IrO₂-coated Ti anodes (DSA) and stainless steel cathodes) and 254 nm UV lamps was established to effectively reduce ferric reagents. The experimental results of the photoelectron-chemical reaction suggested that the current efficiency of reducing ferric ion was improved by increasing the number of electrodes used, and the UV lamps were important to inducing the reduction of ferric carboxylates, which were the major intermediates that were formed upon a particular degree of phenol oxidation. Accordingly, the addition of an initial concentration of 400 ppm ferrous salt and 10,200 ppm hydrogen peroxide (in a continuous mode) resulted in the removal of over 92 % of TOC (initial phenol?=?2,000 ppm, TOC?=?1,532 ppm) by 4 h of the photoelectro-Fenton and the sequential 2 h of the photo-Fenton processes. HPLC was utilized to monitor the formation of aromatic and carboxylate byproducts, and revealed that the aid of photo irradiation eliminated most of the oxalate residue from the final solution, which would have contributed to the 25 % of the TOC that was inactive in the electrolytic system.     

利用硫酸渣生产铁精粉的新工艺研究

实验了一种新的工艺来处理硫酸渣,该方法能很好地脱除烧渣中的硫并富集其中的铁,解决了硫酸渣脱硫难的问题。经过处理后可以将其开发为有用的铁精粉作为炼铁原料或者是生产其他铁系产品,实现了废物的资源综合利用。     

亚铁羟基络合物还原转化水溶性偶氮染料

偶氮染料是印染工艺中应用最广泛的一类染料,目前染料废水脱色是污水处理难题。亚铁混凝处理染料废水过程中可能存在亚铁的还原作用,本实验制备了比溶解态亚铁更具还原反应活性的亚铁羟基络合物(ferrous hydroxycomplex,FHC),以5种不同类型的水溶性偶氮染料为目标污染物,研究FHC还原水溶性偶氮染料的脱色性能。实验结果表明,FHC对活性艳红X-3B、酸性大红GR和阳离子红X-GRL有较好的还原脱色效果,仅投加含铁89.6 mg/L的FHC,染料脱色率达到90%以上,继续增大FHC投加量可以完全脱色;中性枣红GRL的FHC还原脱色效果较差,需加入313.6 mg/L的FHC才能达到90%以上脱色率;134.4 mg/L的FHC能够将直接耐酸大红4BS完全脱色,但其脱色主要以混凝沉淀为主;溶液pH对FHC的还原性能产生重要影响,FHC还原染料脱色的适宜的pH值范围为4～10。该研究为亲水性染料脱色提供了一种新的技术,也为FHC运用于印染废水脱色提供了理论基础。     

亚铁离子活化过硫酸氢钾复合盐降解水溶液中萘普生

在不同pH值、Fe2浓度和过硫酸氢钾复合盐(PMS)浓度下,探究降解萘普生(NPX)的最佳条件,并通过分批投加Fe2+和改变投加顺序的方式,提高降解NPX的效率.结果表明,NPX在pH =3的条件下,降解效果最好;Fe2+浓度改变时,PMS/Fe2+/NPX=1/0.75/1条件下,NPX去除率最高;分批投加Fe2+和先投加Fe2+均可大幅提高NPX去除率.缓慢少量的产生硫酸根自由基(SO4--)更利于处理有机物,Fe2+的浓度则在产生自由基方面起着重要作用.     

Humic acids enhance the microbially mediated release of sedimentary ferrous iron

Iron (Fe) is an essential element for many organisms, but high concentrations of iron can be toxic. The complex relation between iron, arsenic (As), bacteria, and organic matter in sediments and groundwater is still an issue of environmental concern. The present study addresses the effects of humic acids and microorganisms on the mobilization of iron in sediments from an arsenic-affected area, and the microbial diversity was analyzed. The results showed that the addition of 50, 100, and 500 mg/L humic acids enhanced ferrous iron (Fe(II)) release in a time-dependent and dose-dependent fashion under anaerobic conditions. A significant increase in the soluble Fe(II) concentrations occurred in the aqueous phases of the samples during the first 2 weeks, and aqueous Fe(II) reached its maximum concentrations after 8 weeks at the following Fe(II) concentrations: 28.95?±?1.16 mg/L (original non-sterilized sediments), 32.50?±?0.71 mg/L (50 mg/L humic acid-amended, non-sterilized sediments), 37.50?±?1.85 mg/L (100 mg/L humic acid-amended, non-sterilized sediments), and 39.00?±?0.43 mg/L (500 mg/L humic acid-amended, non-sterilized sediments). These results suggest that humic acids can further enhance the microbially mediated release of sedimentary iron under anaerobic conditions. By contrast, very insignificant amounts of iron release were observed from sterilized sediments (the abiotic controls), even with the supplementation of humic acids under anaerobic incubation. In addition, the As(III) release was increased from 50?±?10 μg/L (original non-sterilized sediments) to 110?±?45 μg/L (100 mg/L humic acid-amended, non-sterilized sediments) after 8 weeks of anaerobic incubation. Furthermore, a microbial community analysis indicated that the predominant class was changed from Alphaproteobacteria to Deltaproteobacteria, and clearly increased populations of Geobacter sp., Paludibacter sp., and Methylophaga sp. were found after adding humic acids along with the increased release of iron and arsenic. Our findings provide evidence that humic acids can enhance the microbially mediated release of sedimentary ferrous iron in an arsenic-affected area. It is thus suggested that the control of anthropogenic humic acid use and entry into the environment is important for preventing the subsequent iron contamination in groundwater.     

氯化铁混凝剂中亚铁含量对混凝效果的影响

以城市污水处理厂原水为实验水样,研究了液体FeCl3混凝剂中亚铁含量对其混凝效果的影响。结果表明,液体FeCl3混凝剂中亚铁的含量与其对污水中总磷和COD的去除效果呈非线性相关性,当FeCl3中亚铁含量为25%时,16.0 mg/L的投加量即可使上清液COD降至195 mg/L,去除率达56.7%,总磷降至1.7 mg/L,去除率达70.7%;当FeCl3中亚铁含量继续降低至0.4%时,COD、总磷的去除率仅提高1.1%和1.3%。因此从性价比来讲,FeCl3混凝剂用于污水厂原水混凝时,可适当放宽产品质量标准中亚铁含量限值的规定,有利于降低氯化铁混凝剂的生产成本。     

Effect of ferrous sulfate on parathion degradation in flooded soil.

In an isotope study, the effect of ferrous sulfate on the degradation of parathion was studied under flooded soil conditions. The addition of ferrous sulfate to flooded soil led to more rapid and extensive degradation of parathion with the formation of additional degradation products in ferrous sulfate-amended soil. This effect was not pronounced when ferrous sulfate was added to non-flooded soil or to flooded autoclaved soil. Sulfate, rather than Fe2+, was implicated in the extensive degradation of parathion.     

亚铁螯合剂液相脱除烟气中NOx

总结了近20多年来液相络合法脱除烟气中NOx的研究成果,详细叙述了亚铁氨羧和亚铁含-SH基二类螯合剂单独脱氮和同时脱硫脱氮的反应机理、动力学、吸收液的再生和过程的影响因素,指出了该工艺存在的主要问题,提出了今后的研究方向.