A Mild and Practical Procedure for Tetrahydropyranylation of Alcohols and Phenols Catalysed by Anhydrous Ferrous Sulfate

An easy preparation of tetrahydropyranyl (THP) ethers of alcohols and phenols with 3,4-dihydro-2H-pyran (DHP) in refluxing dichloromethane has been carried out in good to excellent yields under catalysis of anhydrous ferrous sulfate.

Efficacy and Compliance of Oral Iron Poly-Maltose Complex versus Oral Ferrous Sulfate in the Treatment of Iron Deficiency Anemia in Pregnant Women

Objective: To compare the efficacy and compliance of the conventional therapy of iron deficiency anemia (ferrous sulfate) with the new forms of therapy chewable iron tablets: (iron polymaltose complex) in the treatment of iron deficiency anemia in pregnant women. Methods: This Randomized Control Trial study included 290 pregnant women with iron deficiency anemia, and they were randomly allocated to a control group who received ferrous sulfate capsules for two months and study group who received iron polymaltose complex chewable tablets for two months. Complete Blood Picture (hemoglobin level and hematocrit level) and Serum ferritin level were done after four and eight weeks to determine the efficacy. In addition, any complains or side effects had been reported to assess the tolerability of the drugs. Two-factor repeated-measures analysis of variance (ANOVA) was used to compare the change in hemoglobin and serum ferritin levels in both groups. Results: There was no statistical significant difference between the two research groups as regards baseline hemoglobin, and at week 4 from onset of treatment (p values = 0.990, 0.112, consecutively). However, there was statistical significant difference on week 8 of continuous drug intake in both groups in which the iron poly maltose complex research group had significantly higher hemoglobin levels (p value = 0.006). Conclusion: The results of the study showed oral iron polymaltose complex increases Hemoglobin and serum ferritin levels more than oral ferrous sulfate and produces less adverse effects than ferrous sulfate.

Preparation of microsized hematite powder from ferrous sulfate via microwave calcination

The preparation of microsized hematite powder from ferrous sulfate using microwave calcination was investigated based on the TG/DTG curves. The decomposition of industrial ferrous sulfate under air atmosphere was divided into three stages, and a ferrous sulfate sample added with 15% Fe_2O_3 could strongly absorb microwave energy. Therefore, preparing hematite powder from ferrous sulfate using microwave calcination was feasible. Hematite was obtained under the following optimized conditions: calcination temperature, 850 °C; microwave power, 650 W; and sample amount, 40 g. The obtained hematite satisfied the first-grade quality requirements. The total ferrum value was more than 58%, and the total sulfur and phosphorus contents were less than 0.5% and 0.2%, respectively. X-ray powder diffraction and scanning electron microscopy were used to characterize the structure and morphology of microsized hematite powder. The particles were non-spherical in shape, and the average particle size distribution was 10.45 μm. This work provides new potential applications for waste ferrous sulfate.

Effect of purification pretreatment on the recovery of magnetite from waste ferrous sulfate

The present study was conducted to elucidate the influence of impurities in waste ferrous sulfate on its recovery of magnetite. Ferrous sulfate solution was purified by the addition of Na OH solution to precipitate impurities, and magnetite was recovered from ferrous sulfate solution without and with purification pretreatment. Calcium hydroxide was added to the solution of ferrous sulfate as a precipitator. A mixed product of magnetite and gypsum was subsequently obtained by air oxidation and heating. Wet-milling was performed prior to magnetic separation to recover magnetite from the mixed products. The results show that with the purification pretreatment, the grade of iron in magnetite concentrate increased from 62.05% to 65.58% and the recovery rate of iron decreased from 85.35% to 80.35%. The purification pretreatment reduced the conglutination between magnetite and gypsum, which favors their subsequent magnetic separation. In summary, a higher-grade magnetite with a better crystallinity and a larger particle size of 2.35 μm was obtained with the purification pretreatment.

Quality of Drugs Based on Ferrous Sulfate Dispensed in a Basic Health and Commercial Pharmacy in a City in the Amazon Region

Background: For the WHO, anemia is a serious public health problem, with an emphasis on deprivation anemia, which has socioeconomic conditions as determining factors for its development. Among nutritional anemias, the most relevant is iron deficiency, whose main form of prevention and treatment is supplementation with ferrous sulfate dispensed in the public health system, with the need to periodically check whether the drug has the quality required by regulatory health agencies. Thus, the objective of this study was to analyze the quality of the ferrous sulfate medication, from the same laboratory, and dispensed in a basic health unit (BHU) and a commercial pharmacy (CF). Materials and Methods: An analytical, qualitative and quantitative study of ferrous sulfate heptahydrate (25 mg/mL in 100 mL syrup), carried out on 20 BHU and 10 from CF, both from the same laboratory, but in different batches. Samples were subjected to organoleptic analysis and verification of iron content, pH, volume and density. Data were compared with values recommended by the Brazilian pharmacopoeia 5th edition. Results: Three batches were evaluated: 4659 of from the CF;4574 from the BHU1, and 4576 from the BHU2, stored in accordance with RDC 304/19 of ANVISA. All showed compliance with some organoleptic characteristics;and stable values in pH (3.61 - CF;3.67 - BHU1;3.65 - BHU2), density (1.079 - CF;1.088 - BHU1;1.086 - BHU2) and individual volume (not less than 95% of the declared value). However, it was not possible to detect the odor of herbs;the average volume of batch BHU1 was below the declared value, and the iron content of both BHUs was above the maximum value of pharmacopoeia standards. Conclusion: Samples did not show full compliance with the physical and chemical parameters evaluated, suggesting deviation in the quality of the medication.

Reduction leaching of rare earth from ion-adsorption type rare earths ore with ferrous sulfate

The practice ofin-situ leaching of the ion-adsorption type rare earths ore with ammonium sulfate could only leach most of rare earth in ion-exchangeable phase, but not the colloidal sediment phase. Therefore, the reduction leaching of rare earth from the ion-adsorption type rare earths ore with ferrous sulfate was innovatively put forward. The soak leaching process and the column leaching process were investigated in the present study. It was determined that ion-exchangeable phase could be released, and part of colloidal sediment phase rare earth could be reduction leached by the cations with reduction properties. The mechanism of reduction leaching was discussed with the Eh-pH diagram of cerium. Moreover, the stronger reduction of reductive ions, the greater acidity of leaching agent solution, and the higher reductive ion concentration, could result in the higher rare earth efficiency and the bigger ce-rium partition in the leaching liquor. In the ferrous sulfate column leaching process, the rare earth leaching rate and the rare earth effi-ciency were a little higher than with （NH4）2SO4 agent, and the rare earth efficiency and the partitioning of cerium in leaching liquor could be about 102% and 5.31%, respectively. However, the ferrous sulfate leaching process revealed some problems, so compound leaching with magnesium sulfate and a small amount of ferrous sulfate was proposed to an excellent alternative leaching agent for further studies, which may realize efficiency extraction and be environment-friendly.

Intensified bioleaching of low-grade molybdenite concentrate by ferrous sulfate and pyrite

Intensifying effects of ferrous sulfate and pyrite on bioleaching of low-grade molybdenite concentrate were studied in this paper. The experimental results show that the oxidation dissolution of molybdenite can be accelerated with the addition of either ferrous sulfate or pyrite in bi- oleaching medium. Pyrite has better enhancing effect than ferrous sulfate, and the highest molybdenum leaching rate in pyrite-added solutions is 20.85 %, increasing by 12.64 % compared with that in 9 K leaching system. Molybdenum leaching rate does not increase linearly with the increase of the addition of either ferrous sulfate or pyrite in each type solution. Great amounts of [NH4Fe3（SO4）2（OH）6] and [KFe3（SO4）2（OH）6] with different morphologies will be deposited on molybdenite ores when the additions of Fe from ferrous sulfate or pyrite exceed that from 9 K leaching system by 0.5 times, and these deposits hinder the oxidation dissolution of molybdenite to some extent.

人造沸石和PFS去除城镇生活污水氨氮和总磷的实验研究

采用人造沸石和聚合硫酸铁(PFS)处理污水中氨氮和总磷,人造沸石实验采取连续进水模式,从沸石投加量、曝气量和流速(水力停留时间)多角度考察对污水中氨氮的去除,PFS实验从浓度、搅拌转速、混凝时间、沉降时间和取样深度多方面考察对污水中总磷的去除。结果表明:对于NH_(3)-N去除,单独曝气或人造沸石均效果不佳,去除率分别达10.01%±1.69%和49.49%±5.08%,但两者共同作用可极大提升去除效率,达90.55%±1.41%;水力停留时间在2.4~5.5 h范围内越长氨氮出水浓度越低,5.5 h时最低为(2.81±0.14)mg/L。对于TP去除,低浓度PFS(50、100 mg/L)表现出的去除效果不明显,去除率仅达6.62%~10.39%,至400 mg/L时去除率达89.58%±0.79%;转速110 r/min增加至205 r/min,TP去除率仅相差0.27%~3.77%;混凝时间由1 min增至10 min,去除率由52.36%±3.84%提升至87.30%±0.99%,且15 min为最佳沉降时间,之后TP质量浓度趋于平衡;不同取样深度对TP去除无较大影响;最佳实验参数组为PFS浓度400 mg/L,转速110 r/min,混凝10 min后沉降15 min,液面以下池深10%(约2 cm)处取样,出水TP质量浓度可达(0.17±0.01)mg/L,去除率达(89.58±0.79)%,明显优于GB 18918-2002一级A标准。人造沸石和PFS在城镇生活污水氮磷突发状况及深度处理,如某些工艺阶段设备突发事故导致不能运转的紧急情况或出水有深度处理需求的场合具有一定的技术研究和实际应用价值。

罗非鱼养殖尾水絮凝去除效果研究

罗非鱼养殖尾水中含有大量的残饲和粪便等颗粒悬浮物,这些物质是氮、磷营养元素的主要载体。将养殖尾水外排会导致周边水体富营养化。当前常见的尾水处理方式具有占地面积大、投资高、效率低等缺点,影响其推广使用。为解决这一问题,探索采用絮凝工艺对罗非鱼养殖尾水进行处理,选取聚合硫酸铁、三氯化铁、壳聚糖和碳酸镁等4种絮凝剂,通过比较浊度、总悬浮物和化学需氧量的去除效果,筛选出适合用于养殖尾水处理的絮凝剂。结果显示:聚合硫酸铁的效果优于其他3种絮凝剂。在投加量0.4 g/L、pH=8、絮凝时间15 min时,聚合硫酸铁对养殖尾水的浊度、总悬浮固体颗粒物(TSS)和化学需氧量(COD)的去除率分别达到了96.7%、92.6%和95.1%。对絮凝后絮体评价发现,絮体的沉降高度与浊度去除率具有一定相关性,絮体的成长受成核作用的影响。尾水处理前后的zeta电位说明聚合硫酸铁通过破坏尾水中的悬浮物的稳定结构而净化尾水。研究表明,在罗非鱼养殖尾水处理时,可选择聚合硫酸铁作为絮凝剂。

钛白副产硫酸亚铁中镁离子的含量分析

本文研究以酸性铬蓝K为指示剂,以草酸铵为沉淀剂排除Fe^(2+)干扰,用紫外分光光度法测定钛白副产物FeSO_(4)中的Mg^(2+)的含量。实验结果表明,Mg-铬蓝K的最大吸收峰波长为540nm,最佳pH值为9.5,最佳沉淀剂草酸铵的用量为10mL。经加标回收的方法验证了方法的可行性,测出钛白副产物FeSO_(4)中Mg^(2+)含量为1.07%。

硫酸亚铁铵活化过硫酸钠降解土壤吡虫啉的研究

为探究硫酸亚铁铵与过硫酸钠对土壤中吡虫啉降解率的影响,实验设定两种降解试剂添加量均为0.2、0.5、1.0 mmol,土壤中吡虫啉质量浓度为33.0、49.5、66.0μg/g,农作物土壤为水稻、玉米与茶叶土壤,温度为-4、25℃。结果表明:1.0 mmol过硫酸钠与0.2 mmol硫酸亚铁铵对水稻土壤中吡虫啉的降解率最佳,最高可达98.8%,且前120 min内降解速率较快。3种吡虫啉浓度的降解效果没有显著差异(p>0.05);温度对降解率的影响不显著(p>0.05)。土壤中有机碳与pH越低,越有利于过硫酸钠与硫酸亚铁铵降解土壤中吡虫啉。

磁化水复合保氮剂对堆肥过程中氮素损失和微生物群落的影响

为了研究不同保氮剂对快速堆肥过程中氮素损失及微生物群落的影响,该研究以牛粪和秸秆为原料,进行了25 d的好氧堆肥试验。试验中设置了磁化水(T1)、磁化水复合生物炭(T2)、磁化水复合硫酸亚铁(T3)、磁化水复合巨大芽孢杆菌(T4),不添加磁化水和保氮剂作为对照组(CK)。试验结果表明:与对照组相比,T1、T2、T3、T4均延长了堆肥的高温期,分别延长了4、5、2、4 d。T1、T2、T4的最高温较CK分别提高了3.5、8、0.5℃。从温度上来看,T1未进行二次腐熟,缩短了堆肥周期;各处理组的总氮含量较堆肥初始时提高了14.04%、18.89%、37.56%、36.27%、28.47%,总氨气排放量分别为8.12、4.37、6.60、7.32、3.95 g/d。与对照组相比,T1、T2、T3、T4均提高了堆肥的总氮含量,降低了总氨气排放量。T2总氮含量高于其他处理,T1总氨气排放量低于其他处理;与CK相比,T2促进了氮循环基因gdhA的绝对丰度,抑制了拟杆菌门的相对丰度,促进了氮素循环、堆肥进程。与CK相比T3促进了固氮基因nifH、氮循环基因gdhA的绝对丰度,促进了变形菌门的相对丰度,有利于氮素的循环;此外,结构方程显示,T2与NH_(3)排放量呈显著负效应,NH_(3)排放量与总氮损失TN_(loss)呈显著正效应,解释了生物炭通过吸附NH_(3),减少氮素损失。T3与pH值呈显著负效应,pH值与NH_(3)排放量呈显著正效应,NH_(3)排放量与TN_(loss)呈显著正效应,FeSO4的加入降低了堆体的pH值,减少氨气的排放,进而减少氮素损失;综合堆肥过程中的温度、总氮含量、总氨气排放量、氮功能基因的绝对丰度、微生物的相对丰度以及结构方程模型分析,磁化水复合生物炭在快速堆肥过程中表现出最佳的保氮效果和理想的腐熟程度。

硫酸亚铁废液的综合回收利用

在工业生产中每年都会产生大量的硫酸亚铁废液,其中钢铁深加工过程的产出量最大。硫酸亚铁废液中含有硫酸,pH值较低,且含有铁、钴、镍、铝、铬等金属离子,直接排放不仅浪费其中的金属资源,还会对土壤和水体造成严重污染。综合回收硫酸亚铁废液对企业具有巨大的经济效益,对社会具有一定的环境效益。目前主要的处理方法有中和处理法、化学沉淀法、结晶析出法、溶剂萃取法、微生物法等。针对不同生产过程产生的硫酸亚铁废液应采用相应的处理办法。由于中和处理法产生大量金属污泥、结晶析出法的产品市场需求低、溶剂萃取法处理能力低、微生物法处理周期长,化学沉淀法是目前主要采用的回收方法。化学沉淀法操作简单、无需高性能设备,但试验影响因素多,产品性质波动大。硫酸亚铁废液回收产品主要被应用于颜料行业、水处理行业、磁性材料行业等。多数产品仅利用了废液的铁元素,而硫酸和硫元素并未得到回收利用,如何对废液进行综合回收是一个研究重点。由于硫酸亚铁废液中杂质元素含量较多,对其进行提纯具有很大的难度,所需生产成本也较高,因此如何直接利用废液也是未来研究的主要方向。

硫酸亚铁对铝酸盐水泥浆体性能及水化产物的影响

铁相对水泥混凝土耐久性具有显著的积极作用,为拓宽铁相来源,本文研究了铁盐对铝酸盐水泥性能及水化产物的影响。通过将铝酸盐水泥和硫酸盐(二水石膏和硫酸亚铁)复合,使铝酸盐水泥水化生成以钙矾石为主的产物,在此基础上,研究了硫酸盐中硫酸亚铁比例对铝酸盐水泥浆体凝结时间、抗压强度以及体积稳定性的影响规律,并采用XRD和SEM分析水化产物类型以及微观形貌,阐明硫酸亚铁对水泥浆体性能的影响机理。结果表明:适量的硫酸盐可提升铝酸盐水泥浆体的抗压强度;硫酸亚铁对铝酸盐水泥表现出轻微的促凝作用,对膨胀率具有显著的抑制作用;硫酸亚铁对钙矾石的形成具有明显的抑制作用,适量的硫酸亚铁使得所生成的钙矾石尺寸较小,且分布均匀,有利于提升硬化浆体的抗压强度。

镉胁迫下富铁有机肥对芒草生长及镉富集的影响

为了探究镉胁迫下富铁有机肥对芒草生长及镉富集的影响,通过盆栽试验,设置CK(不施肥)、ZCK(施加普通有机肥)和Z2、Z3(施加不同浓度富铁有机肥)处理。结果表明:与CK相比,所有施肥处理均促进了芒草生长,改善了土壤理化性质,抑制了芒草富集重金属,且其中Z2、Z3比ZCK对芒草生长的效果更好。相对于ZCK,Z3的芒草干质量显著增加了131.80%,Z2的芒草根长显著增加了54.22%。此外,Z2地上部的镉含量相比于ZCK显著降低了49.86%,Z3地下部的镉含量相比于CK显著降低了58.94%。研究表明,施加富铁有机肥相对于普通有机肥更能有效促进芒草生长并抑制芒草对镉的富集,该肥料具有对轻度镉污染土壤进行边修复边生产的应用潜力。

无机化学实验“硫酸亚铁铵的制备”教学案例的设计

为进一步落实立德树人根本任务,将“课程思政”融入无机化学实验教学实践,提高课程育人质量,以“硫酸亚铁铵的制备”为例进行教学设计,通过X-射线衍射、场发射扫描电子显微镜对不同条件下制备的硫酸亚铁铵样品的晶体结构和形貌进行表征,培养学生的节约意识、环保意识、创新意识、职业道德、社会责任感、使命感、民族自豪感、家国情怀和勇于探索精神。

电池级磷酸铁的合成工艺优化及其性能研究

文章以硫酸亚铁溶液和磷酸一铵、磷酸的混合溶液为原料,采用一步法制取磷酸铁。通过条件实验,获得最优实验条件:反应陈化温度90℃、pH值=2.00、反应时间为4 h。在上述最优条件下制备出的磷酸铁产品纯度较高、品质好,达到了电池级产品标准。

两种不同铁源合成电池级磷酸铁的研究现状及展望

分别讨论了单质铁和硫酸亚铁合成电池级磷酸铁的研究现状。以单质铁和净化所得钛白副产硫酸亚铁作为铁源,用液相沉淀法合成电池级磷酸铁,工艺简单、杂质少、产品质量稳定性好,一方面可以实现钛白副产硫酸亚铁的资源化综合利用,另一方面可以降低电池级磷酸铁的制造成本,是现有工业生产电池级磷酸铁的两种主流工艺。本文总结了两种不同铁源合成电池级磷酸铁的研究现状,分析了未来应用前景,为之后采用不同铁源合成电池级磷酸铁提供思路和展望。

钛白粉副产硫酸亚铁的综合利用现状

钛白粉的两种制备方法硫酸法与氯化法在我国应用程度与范围不同,硫酸法是我国主流的生产工艺。硫酸法生产会产出大量废气、废水、废渣与副产物,对环境造成严重污染。硫酸亚铁作为硫酸法制备钛白粉工艺的主要副产物,对其进行妥善处理和利用具有极高经济价值与环境效益。基于两种制备工艺的不同,通过对比硫酸法与氯化法的优缺点,对硫酸法副产物硫酸亚铁的综合利用进行了总结,包括直接销售使用与加工后销售使用两个方面,并对钛白粉未来发展进行展望。