化学除磷药剂对EBPR系统处理效能的影响

为研究化学除磷药剂的种类及投加浓度对强化生物除磷系统(EBPR)处理效率的影响,采用以厌氧/好氧方式运行的SBR反应器,以人工配制废水为进水,通过长期试验,分别考察了FeCl_3和AlCl_3两种除磷药剂的投加对系统出水水质的影响。结果表明:随着化学除磷药剂投加浓度的增加,出水COD浓度逐渐降低,而氨氮去除率未随化学除磷药剂投加量的增加而产生明显的变化;低浓度(Fe~(3+)和Al~(3+)的投加浓度分别不大于8 mg/L和6 mg/L)化学除磷药剂将提高微生物活性,高浓度(Fe~(3+)和Al~(3+)的投加浓度分别为24 mg/L和18 mg/L时)产生抑制效果。长期试验中,当Fe~(3+)、Al~(3+)投加量分别为8 mg/L和6mg/L时,即Fe~(3+)、Al~(3+)投加量分别为8.6、7.0 mg/(g VSS)时,系统厌氧释磷量及好氧吸磷量均达到较大值,系统除磷效果最好,此时磷酸盐去除率分别为96.5%和89.5%。     

预氧化强化混凝工艺处理含锰水实验研究

分别研究了次氯酸钠、高锰酸钾、双氧水预氧化强化混凝工艺的除锰效果,优选次氯酸钠为预氧化剂,考察pH、氧化剂投加量、混凝剂投加量、预氧化时间对除锰效果的影响.结果表明,各因素对除锰效果影响程度从大到小依次为:pH>氧化剂投加量>混凝剂投加量>预氧化时间;在9.12的pH,次氯酸钠1.3 mg/L,混凝剂70 mg/L条件...     

化学预处理对用高岭土助凝去除铜绿微囊藻的影响的研究

用高锰酸钾和硫酸铜分别对铜绿微囊藻进行化学预处理,再通过烧杯搅拌试验研究以高岭土为助凝剂,用PAC絮凝去除经过了化学预处理后的铜绿微囊藻的效果。结果表明,高锰酸钾或硫酸铜预处理以不同方式影响叶绿素a（Chla）和浊度的去除。Chla的去除率随高锰酸钾投加量的增加而增加,且在1.0 mg/L投加量时达到92.6%。而硫酸铜预处理时Chla的去除率在其投加量为0.2 mg/L时最高,但在1.0 mg/L时减少到72.8%。高锰酸钾或硫酸铜化学预处理的除藻效果一般不如用高岭土助凝。甚至经高锰酸钾或硫酸铜预处理后,再用高岭土助凝除藻的效果也有所下降。就处理效率和饮用水安全而言,用高岭土助凝是优于用高锰酸钾或硫酸铜进行除藻预处理的技术。     

US/Fe^0/H2O2法对橙黄Ⅱ脱色的研究

以橙黄Ⅱ为研究对象,考察在US/Fe0/H2O2体系中pH值、超声功率、H2O2投加量、铁粉的投加量、通入不同气体对脱色率的影响。结果表明,在pH=2或3时,脱色效果最好;脱色率随超声功率增加而提高;增加H2O2的投加量,脱色效率有明显的提高;增加铁粉的投加量,脱色效率有所提高,但随铁粉投加量的继续增加,脱色率几乎没有变化;通入气体,脱色率有所提高,但通入O2比通入N2的效果要好。     

MAP结晶法与絮凝剂联用预处理化工含磷废水

为达到后续生化处理工艺要求的水质,采用磷酸铵镁(MAP)结晶法与絮凝剂联用预处理化工高含磷废水。以实际化工含磷废水为研究对象,考察了pH值、镁盐投加量、反应温度以及絮凝剂PAFC、PAM投加量对除磷效果的影响。研究结果表明,MAP结晶法除磷的最佳工艺条件为:pH值为9.0,n(Mg2+)∶n(PO43-)为1.6∶1,反应温度为30℃;絮凝剂强化除磷的最佳工艺条件为:PAFC投加量为30 mg/L,PAM投加量为3 mg/L。此时TP、TN、NH3-N、CODCr的去除率分别为98%、74%、64%、87%,满足后续处理要求。     

复合除磷剂的使用与分次投加方式对除磷效果的影响

为使出水TP达到《地表水环境质量标准》(GB 3838—2002)中Ⅳ类标准(TP≤0.3 mg/L),研究比较了FeCl_3、Al_2(SO_4)_3、FeCl_3和Al_2(SO_4)_3按n(Fe:Al)=3:1比例配制的复合除磷剂,以及复合除磷剂在分次投加方式下的除磷效果。结果表明:初始TP浓度为5 mg/L时,复合除磷剂比单独使用FeCl_3、Al_2(SO_4)_3除磷效果好,当除磷剂投加量为100 mg/L时,复合除磷剂磷去除率为96.4%,分别比Al_2(SO_4)_3、FeCl_3高出9.49%、1.68%;多次投加除磷剂时以二次和三次投加时效果较好,当复合除磷剂投加量为100 mg/L,二次投加除磷剂时,磷去除率为98.2%,比一次投加、三次投加时高出1. 8%、0.44%;实际水样连续流试验选择二次投加除磷剂,出水TP含量可稳定达到地表水Ⅳ类标准,并且出水浊度也从2.63 NTU降低至0.99 NTU,去除率达到了62.4%。综合考虑除磷剂消耗量和成本,选择复合除磷剂应用于实际生产较好,每处理1 t含磷量5mg/L的废水成本约为0.22元。     

热改性铝污泥对水中磷的吸附性能

考察了接触时间、pH、投加量对热改性铝污泥吸附磷的影响,确定了其最佳吸附条件和影响因素顺序。结果表明,除磷影响因素依次为磷溶液初始浓度接触时间溶液pH投加量,改性铝污泥吸附除磷的最佳条件:初始磷浓度为60.00 mg/L,pH值为3.0,投加量为4 g/L,振荡反应时间为4 h,改性铝污泥对磷的最高去除率达77.2%。     

几种化学除磷剂除磷效果研究

本文研究了p H、搅拌时长以及加药量三个变量对三氯化铁、氯化铝、氯化钙、硫酸镁以及聚合氯化铝(PAC)、聚合硫酸铁(PFS)六种化学除磷剂除磷效果的影响。结果表明,p H和投加量对化学除磷剂除磷效果有显著影响,搅拌时长超过6 min后对化学除磷剂除磷效果几乎没有影响。p H增大,三氯化铁、氯化铝和硫酸镁的除磷率都先上升后下降,三者的最佳除磷p H分别在4~5、6和9。氯化钙的除磷率随p H增大而增大,其最佳除磷p H为10。复合除磷剂PAC、PFS的除磷率随p H的增大而先增大后减小,二者的最佳除磷p H分别为7.5和8。投加量增多,无机盐类除磷剂的除磷率先增大后不变,三氯化铁的最佳投加量为250 mg/L,氯化铝和硫酸镁的最佳投加量均为200 mg/L。复合化学除磷剂PAC与PFS的除磷率随投加量的增大先增大后减小,二者的最佳投加量均为120 mg/L。     

改性钢渣陶粒对低浓度磷的吸附特征

为了阐明改性钢渣陶粒应用于水体除磷的可行性,通过吸附实验研究了镧铁复合氧化物改性钢渣陶粒对低浓度磷的吸附特性,考察了投加量、pH、共存离子等因素对除磷率的影响,并研究其吸附动力学特性。采用NaOH作为再生剂,比较了吸附饱和的改性钢渣陶粒经不同条件再生处理后的除磷效果。结果表明,对于初始磷浓度1 mg/L的溶液,吸附剂投加量5 g/L,pH为7时,除磷率高达99.07%;HCO_3^-和SO_4-和SO_4^(2-)对除磷的抑制作用较强。吸附动力学过程符合准二级动力学模型。使用1.5 mol/L NaOH浸泡60 min是较为合理的再生条件,一次再生后的除磷率仍可达98.51%。     

生石灰和锁磷剂对河流低含量TP去除性能研究

比较了生石灰和锁磷剂对河流低含量TP的去除性能。结果表明,当投加质量浓度为0～15 mg/L时,生石灰和锁磷剂对TP均无明显去除效果,但生石灰可使系统pH升高,而锁磷剂对系统pH无影响。当两者投加质量浓度为20～200 mg/L时,锁磷剂系统内pH由8.5降至7.5,对TP去除率28.85%～92.31%,有效利用率2.4～9 mg/g;投加质量浓度在80～200 mg/L时去除率可达80%以上,出水TP质量浓度低于0.1 mg/L,生石灰系统内pH由8.5升至10以上,对TP去除率为16.67%～72.22%,有效利用率为1.9～4.38 mg/g;当投加质量浓度在180 mg/L左右时,去除率达最大,出水TP浓度为0.16 mg/L。锁磷剂的综合除磷性能更有优势,其对TP、溶解性磷酸盐都有持久去除作用,最终确定锁磷剂优化投加质量浓度为60 mg/L。     

Iron Homeostasis in Health and Disease

Iron is required for the survival of most organisms, including bacteria, plants, and humans. Its homeostasis in mammals must be fine-tuned to avoid iron deficiency with a reduced oxygen transport and diminished activity of Fe-dependent enzymes, and also iron excess that may catalyze the formation of highly reactive hydroxyl radicals, oxidative stress, and programmed cell death. The advance in understanding the main players and mechanisms involved in iron regulation significantly improved since the discovery of genes responsible for hemochromatosis, the IRE/IRPs machinery, and the hepcidin-ferroportin axis. This review provides an update on the molecular mechanisms regulating cellular and systemic Fe homeostasis and their roles in pathophysiologic conditions that involve alterations of iron metabolism, and provides novel therapeutic strategies to prevent the deleterious effect of its deficiency/overload.     

5kt/a羰基铁粉装置概述

羰基铁粉是五羰基铁Fe(CO)5热分解制取的超微粉末,具有独特的性能,已广泛应用于电子、化工、冶金等领域。目前,世界上仅有少数发达国家掌握羰基铁粉工业化技术。本文阐述了金川集团有限公司5 kt/a羰基铁粉项目建设的必要性及主要工序,装置的建成不仅能稳定我国羰基铁市场,而且能缓和对羰基铁粉末的过度依赖进口。     

澳洲铁矿石粒度分布和铁含量关系的研究与探讨

工作中发现,不同粒径块铁矿的铁含量存在着较大的差异,研究粒度分布与铁含量的关系对手工取样和实验检测有现实的指导和参考意义,同时也能减少贸易纠纷。文章通过选样、筛分、磨样、烘样、溶样等手段对样品进行处理,并按标准ISO9507-1990对样品进行全铁含量检测,考察铁含量随不同粒径块铁矿的变化。结果表明:不同粒径块铁矿的铁含量存在着较大差异,最大偏差达到3.74%,这种差异被认为是块铁矿的结构、组分以及在破碎时不同的破碎方式导致的。     

Comparative Evaluation of Sucrosomial Iron and Iron Oxide Nanoparticles as Oral Supplements in Iron Deficiency Anemia in Piglets

Iron deficiency is the most common mammalian nutritional disorder. However, among mammalian species iron deficiency anemia (IDA), occurs regularly only in pigs. To cure IDA, piglets are routinely injected with high amounts of iron dextran (FeDex), which can lead to perturbations in iron homeostasis. Here, we evaluate the therapeutic efficacy of non-invasive supplementation with Sucrosomial iron (SI), a highly bioavailable iron supplement preventing IDA in humans and mice and various iron oxide nanoparticles (IONPs). Analysis of red blood cell indices and plasma iron parameters shows that not all iron preparations used in the study efficiently counteracted IDA comparable to FeDex-based supplementation. We found no signs of iron toxicity of any tested iron compounds, as evaluated based on the measurement of several toxicological markers that could indicate the occurrence of oxidative stress or inflammation. Neither SI nor IONPs increased hepcidin expression with alterations in ferroportin (FPN) protein level. Finally, the analysis of the piglet gut microbiota indicates the individual pattern of bacterial diversity across taxonomic levels, independent of the type of supplementation. In light of our results, SI but not IONPs used in the experiment emerges as a promising nutritional iron supplement, with a high potential to correct IDA in piglets.     

赤铁矿中全铁测定的一种新方法研究

利用热硫酸溶解赤铁矿样品 ,利用金属铜将 Fe(Ⅲ )还原成 Fe(Ⅱ) ,用重铬酸钾滴定 Fe(Ⅱ)的新方法     

Role of α-Fe2O3 Morphology on the Color of Red Pigment for Porcelain

To produce a new red pigment for Japanese porcelains, some hematite (α-Fe₂O₃) powders produced by different methods were investigated by mixing them with lead-free frit powders and firing them on white porcelain plates at 800°C. Commercial hematite powders and uniform α-Fe₂O₃ powders 155 and 53 nm in diameter which were prepared using conventional- and microwave-hydrothermal reactions, respectively, were used as sources of red pigments. The morphology and dispersion of the above α-Fe₂O₃ powders were found to have a significant effect on the tone of red color for porcelain pigment.     

Kinetic Study of Black Fe2O3-Cr2O3 Pigment Synthesis: I, Influence of Synthesis Time and Temperature

A study was undertaken of the kinetics of the black Fe-Cr oxide pigment synthesis process based on the oxide constituents (Fe₂O₃ and Cr₂O₃). A kinetic model is proposed which enables correlating the degree of transformation advance, expressed as the mass fraction of the arising solid solution (of the same composition as the starting oxide mixture), with synthesis time and temperature. The model is valid for raw materials, range of starting compositions, and operating conditions similar to those used in black Fe-Cr oxide pigment processing in industry.     

Chemically Bonded Phosphate Ceramics: III, Reduction Mechanism and Its Application to Iron Phosphate Ceramics

In this, the last of a series of three papers, we discuss a method of forming iron phosphate ceramics by a reduction process. We report the formation of iron oxide ceramics by reducing hematite with iron in a phosphoric acid solution. The reaction results in a rapid-setting ceramic (at room temperature) with a compressive strength of 3700 psi and a density of 1.7 g/cm³. Although the exact mineral form of the binder is difficult to determine because it is mostly amorphous and hence is not amenable to X-ray diffraction analyses, this material is expected to consist of iron hydrophosphates. The reduction process is very useful in recycling several industrial wastes that are rich in hematite, including iron mine tailings, red mud (a caustic waste from the alumina industry), and machining swarfs. Formation of ceramics with red mud and swarfs is also discussed.     

Microwave-Hydrothermal Synthesis of Monodispersed Nanophase α-Fe2O3

Synthesis of monodispersed nanophase α-Fe₂O₃ (hematite) powder to be used as a red pigment in porcelains was investigated using microwave-hydrothermal and conventional-hydrothermal reactions using 0.018 M FeCl₃·6H₂O and 0.01 M HCl solutions at 100°–160°C. Acicular and yellow β-FeOOH (akaganite) particles 300 nm in length and 40 nm in thickness were dominantly formed at 100°C after 2–3 h, while spherical α-Fe₂O₃ particles 100–180 nm in diameter were preferentially formed after 13 h using a conventional-hydrothermal reaction. However, a microwave-hydrothermal reaction at 100°C led to monodispersed and red α-Fe₂O₃ particles 30–66 nm in diameter after 2 h without the formation of β-FeOOH particles. In this paper, the effect of microwave radiation during hydrothermal treatment at 100°–160°C on the formation yield, kinetics, morphology, phase type, and color of α-Fe₂O₃ was investigated.