用硫化物矿物处理电镀厂废水技术研究

大多数环境工程材料是通过表面作用（ 吸附或共沉淀） 来清除水中的有毒有害物质的,这就要求材料本身具有高表面活性。在搞清硫化物固／ 液界面行为机理的基础上,本文采用高表面活性的硫化物作为吸附剂,以重金属污染大户———电镀厂的酸性废水作为处理对象,研制了一种低成本、高效益、以废治废、简便易行的重金属污染物处理技术———硫化物矿物→鼓气搅动→ＣａＯ 调ｐＨ 值。废水经处理后,完全可以达到国家规定的排放标准。该技术的研制,对保护和净化环境具有重要的现实意义,同时具有广阔的应用前景。     

GT-铁氧体法处理含铬废水实验研究

通过实验研究,确定了ＧＴ－铁氧体法处理电镀含铬废水的各种工艺条件,按照该工艺提供的工艺参数处理电镀含铬废水,可以使处理后的排水中的铬含量达到排放标准。     

累托石层孔材料处理含铬废水的研究

以累托石层孔材料为吸附剂、以FO2为添加剂对含铬电镀废水进行处理，并对其吸附性能做了初步的探讨，实验结果表明，在不改变原水pH值的条件下，吸附剂用量为2.5g/L，还原剂用量为0.5g/L，处理后水中残留铬浓度为0.2mg/L，远低于国标GB8978-1996一级排放标准，累托石吸附铬的反应符合Freundlich吸附经验式：lgQ=-1.9102 0.3545lgC。     

自然状态与加热改性的黄铁矿处理含铬(VI)废水的实验研究

最近几年,人们对一些天然矿物在处理重金属污染物过程中所表现出的高效性、经济性和安全性倍加青睐,并逐渐发展成环境矿物材料研究的方向［１,２］。国外对某些矿物吸附机理也有较系统的评述,有关含铬矿物与有机物的作用也有报道［１,３］。１　实验部分（１）试样来源：黄铁矿取自硫铁矿矿山,经鉴定与粉碎,淘洗,烘干,筛分,磁选后获得。（２）含铬（ＶＩ）废水：用分析纯重铬酸钾（Ｋ２Ｃｒ２Ｏ７）和蒸馏水配制。（３）实验仪器：反应体系的酸度用ＰＨＳ３Ｃ型酸度计测定,反应平衡时的吸光度用ＵＶ１６０Ａ分光光度计测定,…     

H2O2在α-Fe2O3表面非均相氧化SO2机理的模拟研究

通过密度泛函理论模拟了H_2O_2和SO_2气体在矿物氧化物(α-Fe_2O_3)表面上的非均相反应,研究了H_2O_2和SO_2在α-Fe_2O_3(001)表面的吸附机制和氧化机制。研究结果表明,SO_2、H_2O_2均在α-Fe_2O_3(001)表面通过Fe原子进行吸附,H_2O_2相比于SO_2优先吸附在α-Fe_2O_3(001)表面,且H_2O_2在表面的赋存形式趋向于两个·OH形式吸附。通过二者共吸附的局域态密度、差分电荷密度、Mulliken电荷布局分析结果发现,SO_2和H_2O_2的共吸附形式是通过H_2O_2产生的·OH吸附在α-Fe_2O_3(001)表面,同时SO_2被H_2O_2产生的·OH氧化[S(SO_2)-电荷布局:0. 79 e→1. 32 e; O(H_2O_2)-电荷布局:-0. 77 e→-1. 11 e]形成·OH+SO_2团簇。模拟结果表明大气微量气体H_2O_2能够在矿物氧化物表面介导SO_2吸附并促进SO_2的转化,为理解H_2O_2在大气中非均相氧化SO_2的反应过程提供了理论依据。     

HONO在γ-Al2O3(110)表面非均相氧化SO2机理的第一性原理研究

为研究亚硝酸(HONO)在γ-Al_2O_3(110)表面非均相氧化SO_2的机理,基于密度泛函理论(density functional theory,DFT)的第一性原理计算了SO_2和HONO在γ-Al_2O_3(110)表面的吸附机制和氧化机制。结果表明,SO_2以分子的形式吸附在完整或缺陷的γ-Al_2O_3(110)表面,而HONO仅在完整表面上以分子的形式存在。表面氧缺陷的存在不仅会增强SO_2和HONO的吸附强度,而且能诱导HONO在含氧缺陷表面的分解(HONO→NO+·OH)。通过局域态密度(partial density of states,PDOS)和Mulliken电荷布局分析表明,HONO的分解遵循Haber-Weiss机制。当SO_2和HONO共同吸附在氧缺陷表面时,HONO分解产生·OH,氧化SO_2形成HOSO_2团簇分子。该研究不仅有助于理解HONO在矿物氧化物表面氧化SO_2的作用,而且为解释大气硫酸盐气溶胶的形成提供了理论依据。     

铁硫化物矿物作为微生物电子受体的实验研究

微生物生命活动的进行需要通过一系列氧化还原反应获取能量,这一过程中伴随电子由电子供体向电子受体的转移。通常情况下,微生物以有机底物充当电子供体,氧气、硝酸根等作为电子受体。对于自然界的天然矿物,其构成中的可     

赤铁矿高温原位X射线衍射研究

在空气和真空条件下对α-Fe_2O_3粉末进行了从室温到1 000℃的高温原位X射线衍射研究,分别修正了空气和真空条件下赤铁矿在27~1 000℃范围内的晶胞参数,从而得到了晶胞参数随温度变化的关系和赤铁矿在空气和真空条件下的热膨胀系数,并得出了热膨胀系数与温度的关系,即赤铁矿的热膨胀系数不随温度变化。赤铁矿在空气气氛下的热膨胀系数为αa=9.603 16×10~(-6)/℃,αc=6.647 67×10~(-6)/℃,β=2.606 33/℃;真空气氛下的热膨胀系数为αa=9.006 79×10~(-6)/℃,αc=6.891 23×10~(-6)/℃,β=2.511 51/℃。     

湖南芙蓉锡多金属矿床流体包裹体地球化学研究

湖南芙蓉锡多金属矿床是中国最近发现的具有巨大找矿潜力的锡矿田，本文对白蜡水矿区和狗头岭矿区中主要的4种矿化类型（矽卡岩型、蚀变花岗岩、锡石硫化物型、云英岩型）进行了系统的流体包裹体研究，研究表明：该矿床中流体包裹体类型复杂，包括富含CO₂包裹体、气液包裹体、含子晶包裹体和气相包裹体。成矿流体为富含CO₂、CH₄等挥发分的高盐度、高温度的岩浆期后热液，成矿流体压力为1800~179 bar。锡成矿过程早期曾发生过流体不混溶和沸腾作用。CO₂相的分离导致热液流体的pH值升高，低盐度、低温大气降水的混入，导致成矿流体的温度进一步降低和锡石的沉淀。     

天然黄铁矿除Cr（Ⅵ）中Cr2S3物相的发现

利用天然黄铁矿处理含Cr(Ⅵ)废水实验,在反应中与反应后黄铁矿表面和胶体沉淀物中明显出现Cr2p的XPS能谱峰,能拟合出574.7～575.1eV、576.6～576.9eV和578.2～578.7eV3个峰位,分别代表Cr2S3、Cr2O3和CrO3物相。在实验过程中新发现Cr2S3沉淀物相,表明在常温常压下的水溶液介质中也能产生铬的硫化物物相。充分利用这些含铬物相,能使天然黄铁矿包括天然磁黄铁矿在还原Cr(Ⅵ)的同时,无需加碱就可将Cr(Ⅲ)沉淀转移到胶体沉淀物中,处理后的上清液中全Cr含量低于1.5mg/L的国家允许排放标准。天然黄铁矿自身溶解出的重金属含量很低,不影响处理后的出水水质。开发利用Cr2S3等含铬沉淀物相,便于推广应用天然黄铁矿和磁黄铁矿还原Cr(Ⅵ)同时沉淀Cr(Ⅲ)的一步法除铬新工艺。     

碱处理对河北围场天然沸石结构和性能的影响及其机理研究

采用NaOH对围场地区天然沸石进行处理,采用X射线衍射仪、红外光谱仪、N2吸附-脱附技术、扫描电子显微镜等对材料进行表征分析,采用水蒸气吸附法评价材料的亲水性,采用Cr3+和Mn2+评价材料的离子交换性能,探讨了碱处理对天然沸石的结构、亲水性和离子交换性能的影响及其机理.实验结果表明,围场地区天然沸石中主要含有斜发沸石...     

国内矿物治理重金属废水研究进展与展望

综述了我国利用天然矿物治理重金属废水方面的研究新成果。天然铁的硫化物、天然铁锰的氧化物、方解石与磷灰石等具有良好的表面吸附与氧化还原化学活性;不同介质中它们能不同程度地表现出对Cr^6 、Pb^2 、Hg^2 、Cd^2 等重金属离子的吸附作用,可广泛用于重金属废水处理。矿物吸附重金属离子机理的研究表明,矿物对重金属的吸附是矿物表面与无机重金属离子之间的表面作用过程,包括矿物表面功能基与重金属离子的配位反应、矿物表面氧化还原反应和沉淀转化作用,以及矿物表面离子交换吸附作用等。     

The Speciation of (CH3)2Sn2+ in Electrolyte Solution Containing the Major Components of Natural Waters

Hydrolysis constants of dimethyltin(IV) cation, in different salt solutions (CaCl₂: 0.15 I 0.90; MgCl₂: 0.30 I 0.60; NaCl-–NaClO₄, NaCl-–NaNO₃ mixtures: I = 3; NaCl-–Na₂SO₄ mixtures: I = 1 mol dm^-3) were determined by potentiometric ([H⁺]-glass electrode) measurements. These data, together with previous data (De Stefano et al., 1996b) were interpreted in terms of DHT (Debye–Hückel type) and Pitzer equations. The mixed electrolyte solution results also allowed us to obtain and parameters for the Pitzer equation. Calorimetric measurements were made at different ionic strengths in order to find the temperature dependence of hydrolysis constants and of the relative interaction parameters. The body of results allows us to determine the speciation of natural waters in a wide range of ionic strengths and temperatures.     

The Effect of Cr2O3 on the Partial Melting of Spinel Lherzolite in the System CaO-MgO-Al2O3-SiO2-Cr2O3 at 1{middle dot}1 GPa

Chromium as Cr³⁺ substitutes for octahedrally coordinated Alin upper-mantle minerals, thereby reducing the activity of Al₂O₃in the system and hence the concentration of Al₂O₃ in partialmelts. The effect of Cr₂O₃ on melt compositions multiply saturatedwith the spinel lherzolite phase assemblage has been quantifiedin the system CaO–MgO–Al₂O₃–SiO₂–Cr₂O₃at 1·1 GPa as a function of 100 Cr/(Cr + Al) in the spinel(Cr#_sp). The decrease of Al₂O₃ in the melt with increasing Cr#_spis accompanied by increasing MgO and SiO₂, whereas CaO remainsalmost constant. Consequently, the CaO/Al₂O₃ ratio of the meltincreases with Cr#_sp, and the melt becomes richer in normativediopside, hypersthene and quartz. The effect may explain certainmantle melts with unusually high CaO/Al₂O₃ ratios. The concentrationof Cr₂O₃ in the melt remains low even at high Cr#_sp, which meansthat the strong effect of Cr₂O₃ on partial melting equilibriais not readily apparent from its concentration in the melt itself.The existence of a highly refractory major component such asCr₂O₃ nullifies simplified conclusions from the ‘inverseapproach’ in the experimental study of basalt petrogenesis,as there is insufficient information in the composition of thepartial melt to reconstruct the conditions of melting. KEY WORDS: basalt petrogenesis; partial melting; reversal experiment; spinel lherzolite; system CMAS–Cr₂O₃; CaO/Al₂O₃ of melt; effect of Cr₂O₃     

13X沸石处理含赖氨酸废水的实验研究

用合成的13X沸石对废水中氨基酸(赖氨酸)进行静态吸附实验,研究了pH、温度、吸附时间、沸石用量等对吸附率的影响,结果表明,室温下沸石对赖氨酸的吸附平衡时间为30min,pH=pKa1=2.2时,赖氨酸在沸石上的吸附效果最好,吸附率大于82%,饱和吸附量达51.73mg.g-1。吸附等温线近似呈直线型,表明离子交换机制是沸石吸附氨基酸的主要方式。对已饱和吸附的沸石用饱和氯化钠溶液进行再生实验,赖氨酸的解吸率大于95%,沸石可重复使用。实验研究表明可用13X分子筛处理含氨基酸废水,为实际处理含氨基酸废水提供了可行性依据。     

鄂尔多斯盆地东南部奥陶系马家沟组碳酸盐岩中黄铁矿成因

鄂尔多斯盆地东南部广泛发育黄铁矿,通过对黄铁矿的矿物学特征、元素组成、硫同位素等的分析,讨论和揭示了该黄铁矿的成因。岩石矿物学研究结果显示黄铁矿具有多种赋存形式,呈零星或集合体充填于膏溶孔和溶蚀孔洞中,或与层状硬石膏相伴生;硫同位素地球化学分析结果显示,黄铁矿的δ34S值介于10. 50‰～24. 00‰之间,平均值为17. 33‰。盆地东南部具备薄层硬石膏、高温驱动和充足的烃类气体等热化学硫酸盐还原作用发生的条件,结合其产状证据认为黄铁矿形成于热化学硫酸盐还原作用。黄铁矿出现的地层中Fe含量较高,介于3 387. 50×10~(-6)～23 112. 50×10~(-6)之间,平均值为13 233. 33×10~(-6),为黄铁矿的形成提供了物质来源。盆地东南部多产低含H2S天然气,研究认为黄铁矿的形成是造成该地区H2S含量较低的主要原因。     

Crustal thickness and VP/VS variations in the Grenville orogen (Ontario, Canada) from analysis of teleseismic receiver functions

We have developed a simple semblance-weighted stacking technique to estimate crustal thickness and average V_P/V_S ratio using teleseismic receiver functions. We have applied our method to data from 32 broadband seismograph stations that cover a 700 × 400 km² region of the Grenville orogen, a 1.2–0.98 Ga Himalayan-scale collisional belt in eastern North America. Our seismograph network partly overlaps with Lithoprobe and other crustal refraction surveys. In 8 out of 9 cases where a crustal-refraction profile passes within 30 km of a seismograph station, the two independent crustal thickness estimates agree to within 7%. Our regional crustal-thickness model, constructed using both teleseismic and refraction observations, ranges between 34.0 and 52.4 km. Crustal-thickness trends show a strong correlation with geological belts, but do not correlate with surface topography and are far in excess of relief required to maintain local isostatic equilibrium. The thickest crust (52.4 ± 1.7 km) was found at a station located within the 1.1 Ga mid-continent (failed) rift. The Central Gneiss Belt, which contains rocks exhumed from deep levels of the crust, is characterized by V_P/V_S ranging from 1.78 to 1.85. In other parts of the Grenville orogen, V_P/V_S is found to be generally less than 1.80. The thinnest crust (34.5–37.0 km) occurs northeast of the 0.7 Ga Ottawa–Bonnechere graben and correlates with areas of high intraplate seismicity.     

Fine structure in photoluminescence spectrum of S<Subscript>2</Subscript><Superscript>−</Superscript> center in sodalite

The photoluminescence and excitation spectra of sodalites from Greenland, Canada and Xinjiang (China) are observed at 300 and 10 K in detail. The features of the emission and excitation spectra of the orange-yellow fluorescence of these sodalites are independent of the locality. The emission spectra at 300 and 10 K consist of a broad band with a series of peaks and a maximum peak at 648 and 645.9 nm, respectively. The excitation spectra obtained by monitoring the orange-yellow fluorescence at 300 and 10 K consist of a main band with a peak at 392 nm. The luminescence efficiency of the heat-treated sodalite from Xinjiang is about seven times as high as that of untreated natural sodalite. The emission spectrum of the S₂ ⁻ center in sodalite at 10 K consists of a band with a clearly resolved structure with a series of maxima spaced about 560 cm⁻¹ (20–25 nm) apart. Each narrow band at 10 K shows a fine structure consisting of a small peak due to the stretching vibration of the isotopic species of ³²S³⁴S⁻, a main peak due to that of the isotopic species of ³²S₂ ⁻ and five peaks due to phonon sidebands of the main peak.