Fenton处理对污泥脱水性、重金属形态及生物淋滤效率影响

为考察污泥预处理过程中重金属迁移转化规律,通过投加不同量的Fenton试剂对污泥进行处理,分析了Zn、Cd、Mn、Ni四种重金属的化学形态变化与后继生物淋滤过程的溶出行为。研究结果表明,污泥经Fenton处理后,毛细吸水时间在短时间内降低,但对生物淋滤后最终的污泥脱水性没有显著提升作用;重金属Zn、Cd、Mn的不稳定态（弱酸提取态、可还原态）比例不同程度提高,当投加Fe²⁺=1.00g/L、H₂O₂=9.00g/L时,其比例分别由37%、84%、79%上升至90%、93%、84%,但Ni无明显变化。此外,Fenton处理污泥中Zn、Cd、Mn、Ni四种重金属生物淋滤后含量分别由3451.52mg/kg、6.45mg/kg、443.40mg/kg、94.96mg/kg降至376.74mg/kg、1.10mg/kg、141.66mg/kg、21.77mg/kg,比单独生物淋滤处理污泥重金属残余量分别降低了36.20%、26.17%、30.92%和27.89%。利用动力学方程较好地描述了生物淋滤过程中Zn、Cd、Mn、Ni四种重金属的溶出速率的相对大小,排序为Mn＜Cd＜Zn＜Ni。     

微波辐射下香草醛改性壳聚糖的制备及其对金属离子的吸附

应用微波辐射法合成了香草醛接枝壳聚糖,用NaBH4进行还原。探讨了改性壳聚糖在25℃下对Ni2+、Mn2+、Cr6+的吸附及时间、离子浓度、pH值对吸附效果的影响。结果表明,还原后的改性壳聚糖比壳聚糖吸附性能明显改善,其对Ni2+、Mn2+和Cr6+的吸附容量分别可以达到116.23,63.83,47.27 mg/g。     

Determination of Mineral Oil-Saturated Hydrocarbons (MOSH) in Vegetable Oils by Large Scale Off-Line SPE Combined with GC-FID

A method based on an off-line large-scale solid phase extraction (SPE) approach combined with conventional gas chromatographic-flame ionization detection (GC-FID) was developed to determine the mineral oil-saturated hydrocarbons (MOSH) in vegetable oils. A large-scale SPE column loaded with 10 g of activated silica gel impregnated with 1% silver nitrate which was used to retain lipids and olefins in vegetable oils and the MOSH in the oil samples was eluted with hexane. Then 2 μL concentrated solution was splitlessly injected into a common GC-FID instrument. The quantification limit reached 2.5 mg/kg when the MOSH fraction was concentrated to 0.1 mL. The accuracy of this procedure, as assessed by measuring the recoveries from spiked oil samples, was higher than 80%. This procedure was applied to analyze the MOSH in 38 commercial vegetable oils from Chinese market, which was the first survey of mineral oil contaminant in Chinese edible oils. The oil samples contaminated with different levels of MOSH, among which, 15 samples contained no mineral oils and 3 samples were contaminated with more than 50 mg/kg of MOSH. The highest contamination level was found in one of rice oils, in which the concentration of MOSH was up to 713.36 mg/kg. Of the 9 types of oils analyzed, camellia oil contained MOSH ranging between 6.76 and 78.49 mg/kg, averaging 46.72 mg/kg, indicating a higher contamination level than other types of oils. The results suggested that it is necessary to routinely detect mineral oil contamination in vegetable oils for food safety.     

DUO-ICP-AES测定精对苯二甲酸中的钴、铬、铁、锰、钼、镍、钛

采用DUO-ICP-AES同时测定精对苯二甲酸中钴、铬、铁、锰、钼、镍、钛,并对仪器的分析线选择、背景校正、入射功率、雾化器压力、辅助气流量、冷却气流量、蠕动泵转速的影响及共存元素的干扰、硝酸铯灰化助剂等因素进行了详细的研究。方法的检测限:钴0.0097 mg/L;铬0.0021 mg/L;铁0.0078 mg/L;锰0.0012 mg/L;钼0.0027 mg/L;镍0.016 mg/L;钛0.0027 mg/L,回收率和精密度分别为93.0%～99.5%和0.37%～3.2%。该方法快速简便,具有良好的精密度和准确度,适用于进出口精对苯二甲酸的日常检验。     

Behavior of Ni(II) and Mn(II) in single and binary aqueous solutions in the adsorption process by rice hull ashes (RHA)

The retention of nickel and manganese by calcined rice hull ashes (RHA) in single and binary solutions was determined as a function of metal concentration and time. The maximum adsorptions of RHA for Ni(II) and Mn(II) were 7.27 and 6.45 mg/g from monocomponent solutions, and 4.6 and 3.8 mg/g from bicomponent solutions, respectively. The kinetic experimental data best fit a pseudo-second-order model. The k₂ is higher for Mn(II) than Ni(II) considering the monocomponent solutions and this parameter is similar between them if the bicomponent solution is considered. The metallic species were partially desorbed from RHA by water.     

重金属离子对A~2/O工艺脱氮效能的毒性影响分析

以浙江某城市污水处理厂重金属离子引起出水水质恶化为研究对象,分析了城市污水厂处理厂进水、出水、活性污泥中Mn2+、Ni2+、Cr6+、Cu2+、Zn2+等重金属离子的含量。结果表明,进水、出水、活性污泥(干泥)中Mn2+含量分别为0.476 5～8.248 7 mg/L、0.472 7～4.630 5 mg/L、1 582.2 mg/kg干泥,Mn2+是影响该污水处理厂水质净化效果主要原因。通过采取控制进水水质、加大活性污泥排放量、接种污泥等措施,最后恢复了该厂的正常运行。     

Characterization of the Seed Oil and Meal from <Emphasis Type="Italic">Monechma ciliatum</Emphasis> and <Emphasis Type="Italic">Prunus mahaleb</Emphasis> Seeds

The oil and meal from Monechma ciliatum (black mahlab) and Prunus mahaleb (white mahlab) seeds were characterized for their physicochemical properties. The oil content was found to be 30.95 and 13.15% in white and black mahlab seeds, respectively. The refractive indices of white mahlab oil (WMO) and black mahlab oil (BMO) were 1.475 and 1.470, and specific gravities were 0.8511 and 0.8167 g/cm³, respectively. Saponification values were 184.23 and 180.3 mg KOH/g, peroxide values were 2.54 and 4.43 meq/kg, and unsaponifiable matter was 0.92 and 0.66%, respectively. The major fatty acids were palmitic 4.5%, stearic 16.0%, oleic 47.3%, and linoleic 31.4% in BMO, while in WMO they were palmitic 5.7%, oleic 45.0%, and linoleic acid 47.0%. A moderate amount of tocopherols were found at 45.2 and 28.5 mg/100 g in BMO and WMO, respectively. Protein content was found to be 21% in black and 28% in white mahlab seeds. The total amount of amino acids in black and white mahlab seeds was found to be 783.3 and 1,223.2 mg/g N, respectively. The concentration (on ppm dry-weight basis) of major elements (Ca, K, and Mg) and of minor elements (Al, Pb Ni, Mn, Cu, Cr, Co, and Fe) was also determined in the meals.     

电镀废水中铁、铜、铬、镍的快速光度法分析

采用多波长分光光度法对Fe~(3+)、Cu~(2+)、Cr~(3+)、Ni~(2+)等进行定量分析。研究了Ca~(2+)、Mg~(2+)、Zn~(2+)的存在对分析结果的干扰,确定了每一种金属离子的最佳吸收波长,并建立了有效的线性方程。通过对Fe~(3+)、Cu~(2+)、Cr~(3+)、Ni~(2+)混合标准液进行测定,验证线性方程的准确性。考虑到不同样品金属离子的质量浓度不同,对其测定下限进行研究,并分析每种金属离子测定时的影响因素。结果表明:Fe~(3+)、Cu~(2+)、Cr~(3+)、Ni~(2+)的测定下限分别为0.5mg/L、1mg/L、5mg/L、5mg/L。     

Zinc and nickel determination in liquid edible oils by FAAS after the extraction

A new method has been developed for the extraction and determination of zinc and nickel in liquid edible oils by using the complexation of these metals with [N,N′‐bis(salicylidene)‐2,2′‐dimethyl‐1,3‐propanediaminato]. Zn(II) and Ni(II) complexes with a tetradentate Schiff base have been investigated spectrophotometrically. Experimental extraction conditions for these metals from liquid oil standards were optimized using central composite design. Optimum conditions for Zn(II) and Ni(II) extractions from oil have been found close to each other. The ratio of the volume of used Schiff base solution to the amount of oil (V_LDM/m_oil; mL/g), the stirring time and the temperature were round about 1.00 mL/g, 55 min, 32°C, respectively, for simultaneous determination of both metals in same sample. The recovery percentages at the optimum experimental conditions were found 98.9 ± 2.8 and 101.8 ± 4.7 for Zn(II) and Ni(II), respectively. The proposed method was applied on the raw and spiked samples such as olive oil, sunflower oil, corn oil, canola oil and obtained recovery values were between 93.7–107.2 and 93.1–101.1% for Zn(II) and Ni(II), respectively. Practical applications: There is interest in the determination of metals in liquid edible oils because of their catalytic effect on the oxidation reaction of oils. A new method for the determination of Zn(II) and Ni(II) in liquid edible oils which does not require any digestion or decomposition was developed. This study offeres a cheap, rapid, accurate, sensitive, risk‐free, and practical metal determination method after the extraction.     

Determination of rare earth elements in Niger Delta crude oils by inductively coupled plasma-mass spectrometry

A profile for rare earth elements (REE) of crude oils from the offshore – shallow water and onshore fields in the Niger Delta, analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) is reported. The oil samples were prepared for ICP-MS measurement by acid digestion into colourless aqueous solution. The analysis method was validated using standard reference materials SLRS-4 and NIST-1640. Results showed percentage recovery values that ranged from 81.8% to 115.4% for Co, Cu, Fe, Mn, Ni, Sb and U and from 98.8% to 104.7% for Co, Cu, Fe, Mn, Ni and Sb. The magnitude of deviation recorded in SLRS-4 for Co and Fe suggests that it may not be a suitable standard for these elements using the ICP-MS method outlined in this study. The concentrations of the detected REE; La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Er and Yb ranged from 0.01 to 1.58 ppb with an average of 0.98 ppb (%RSD < 5) for the oil samples analyzed. Light REEs (LREE) were identified in all the oil samples while heavy rare earth elements (HREE) were identified in offshore oil samples only. LREE patterns constructed from chondrite-normalized values for the oils show some similarities among the oils, which suggest common origin of the oils and that the REE got into the oils from similar source. While those with different chondrite-normalized REE patterns suggest different source input of the REE. This indicates that REE will be a useful tool in oil–oil correlation. Statistical evaluation of these oils by cluster analysis using the REE as variables clearly discriminated according to their geographic sources. Biodegradation has pronounced effect on the concentration of REE in oils. Therefore, REE contents of oils will be useful in oil classification. ICP-MS proved to be a versatile method for the determination of rare earth elements in Niger Delta oils.     

衡阳市食用菌中铅、镉、汞调查评价

检测衡阳市食用菌中重金属铅、镉、汞的含量,探讨重金属污染来源,提出相应的预防和干预措施。通过随机采样的方法采集鲜、干食用菌,利用石墨炉原子吸收光谱法和冷原子荧光法,分别检测食用菌中铅、镉与汞的含量。80份食用菌中,铅未见超标,其中含量最高的为干松乳菇达1.0222mg/kg;镉总超标率为15%,其中含量最高的为干香菇达0.2642mg/kg;汞也未见超标,其含量最高的为鲜香菇达0.0251mg/kg。本研究表明衡阳市市场上销售的食用菌存在重金属污染的风险不大。不同类型的食用菌样品以干、鲜香菇、干松乳菇镉超标较多;不同重金属类型以镉污染的风险相对较大,铅、汞污染的风险较小。     

The determination of light petroleum residues in refined oils and fats

A rapid, direct injection gas liquid chromatographic (GLC) method for determining residual light petroleum in edible vegetable oils has been developed. The response is linear at levels between 0.05–0.5 mg hexane/kg oil. A sample containing 0.2 mg hexane/kg oil was analyzed for repeatability, giving a standard deviation of 0.008 mg/kg, equivalent to a coefficient of variation of 4%. Separation of pentane, hexane, heptane, octane and decane was obtained by this method. A survey of 23 samples of freshly refined vegetable oils obtained from 13 U.K. refiners in 1981 showed that these all contained less than 0.05 mg hexane/kg oil.     

Electrocoagulation of Soluble Oil Wastewater: Parametric and Kinetic Study

Soluble oils (cutting oils) in aqueous solution are used extensively in the engineering and metal working industries, as coolants, metal forming fluids, and/or lubricants. Hysol-X is a general-purpose cutting oil used in 1–10% concentration in aqueous solution. This paper investigates demulsification of soluble-oil-water emulsion using electrocoagulation with aluminum electrodes. It examines the current efficiency and the pH variation of the system due to electrocoagulation and the effect of pH of the oil-water emulsion, current density, and temperature on the demulsification process. A simple first order kinetics fits the experimental data at a constant value of current density. The optimum pH and current density were found to be 6.50 and 138.8 A/m², respectively. Apparent electrode current efficiency was found to be 115.5%. Temperature has significant effect on emulsion stability and solution pH. At a lower temperature of 20°C or a higher temperature of 60°C, the turbidity (or oil) removal is found to be very high. More than 99% oil separation is achieved in 3 h at 20°C. The residual aluminum concentration in the treated water at an initial pH 6.5 is found to be 0.001 mg/l, well below the statutory discharge standard value.     

Selective corrosion study by anodic stripping of CrNi steel

A method consisting in galvanostatic anodic stripping of layers with thicknesses of the order of nanometers combined with gamma-spectrometric analysis of soluble anodic reaction products has been developed for the purpose of a study of concentration profile of alloy components in the surface of alloys after a corrosion process.Suitable conditions as regards the stripping solution and the electrochemical parameters were investigated to ensure reliable determination of the quantity of stripped metal based on the Faraday relationship and to provide for a uniform removal of metal from the surface. Experimentally verified constants for the conversion of passed electric charge to stripped layer thickness are given for steel grades FeCr17, FeCr18Ni5Mn9, FeCr18Ni9, FrCr18Ni10Mo2 and FeCr20Ni38Mo6, the average accuracy being ±1.5 per cent.Two examples are presented to illustrate the determination of the concentration profile of components in the surface of steel grade FeCr18Ni9.     

钛柱撑蒙脱石对镍离子和锰离子的吸附机理

以钠基蒙脱石(Na-MMT)、钛酸四丁酯作基质材料,通过溶胶-凝胶法制备了钛柱撑蒙脱石(Ti-MMT)。利用XRD、FTIR及SEM对Ti-MMT进行了结构表征,考察了不同吸附条件对Ti-MMT吸附Ni~(2+)和Mn~(2+)的影响,并重点分析水溶液pH对Ti-MMT Zeta电位及吸附的影响,探究了Ti-MMT吸附Ni~(2+)和Mn~(2+)的机理。结果表明:Ti-MMT具有较大的晶面间距(d001=2.94 nm);pH对吸附Ni~(2+)与Mn~(2+)有较大影响,去除率随初始水溶液pH增加而提高。在pH=7,Ni~(2+)和Mn~(2+)初始质量浓度为50 mg/L,Ti-MMT投加量分别为5和9 g/L时,Ni~(2+)在318 K下吸附120 min,吸附量可达9.46 mg/g,去除率可达94.59%,Mn~(2+)在328 K下吸附180 min,吸附量可达4.82mg/g,去除率可达86.73%。此外,Ti-MMT对两种离子的吸附都更符合Temkin等温吸附模型及拟二级动力学模型,吸附过程受液膜扩散、颗粒内扩散等环节控制,且以离子交换的化学吸附为主。热力学分析表明,Ti-MMT对Ni~(2+)的吸附属于自发吸热熵增过程,而Mn~(2+)属于吸热熵增的非自发过程。     

Pd(II) ion adsorption onto emulsion gel beads in a fixed bed

We developed previously an emulsion gel adsorbent for improved metal adsorption. This study focuses on a continuous adsorption–desorption process of metal ions from a solution onto emulsion gel beads using the fixed-bed method. The monodisperse millimeter-sized emulsion gel beads, a polymeric hydrogel containing randomly distributed oil microdroplets of di-n-hexylsulfide as an extractant, were prepared using an automatic production method combining sedimentation polymerization and two-fluid atomization. The isotherms and the kinetics for Pd(II) adsorption were investigated. A continuous adsorption–desorption process was successfully demonstrated, and the breakthrough curve was successfully predicted by a mathematical analysis.     

Development of a flow injection chemiluminescent assay for the quantification of lipid hydroperoxides

An automated flow injection chemiluminescence (FICL) system for measuring lipid hydroperoxide (LOOH) concentrations in oils was developed. Initially, a crude oil-in-water emulsion (formed by mixing solvent-diluted oil with the aqueous-based CL compound, luminol, and the catalyst for the reaction, cytochrome c) was tested. The assay was rapid (60 samples per hour), reproducible (CV no greater than 10%, n=3) and had a low sample requirement (1 mg of oil) because of its high sensitivity (0.5 nmol LOOH). CL intensity was influenced by the amount and type of oil under analysis. Owing to these factors, quantitative data were attainable only with a uniform oil concentration and with a calibrant derived from an oil equivalent to that under analysis. This method yielded quantitative data in good agreement with an iodometric titration assay for LOOH (r=0.9204). A refinement of the first method consisted of replacing the luminol and cytochrome c CL compounds with lucigenin, resulting in an assay insensitive to α-tocopherol. A monophasic reaction solution was devised to remove the effect of turbidity; however, the CL signal was still influenced by oil type. Therefore, quantitative data were still attainable only when the same type of oil was used for calibration.     

Emulsion gel beads prepared by sedimentation polymerization using two-fluid atomization and their Pd(II) ion adsorption properties

An emulsion gel adsorbent which was a polymeric hydrogel containing randomly distributed oil microdroplets of an extractant was developed for improved metal adsorption in our previous study. This study focuses on the preparation of monodisperse, millimeter- or sub-millimeter-sized emulsion gel beads, for which a novel production method combining sedimentation polymerization and two-fluid atomization is proposed. The method involves the drop-wise addition of a pre-gel oil-in-water emulsion solution into a silicone oil through a nozzle, with nitrogen gas flow, and the subsequent free-radical polymerization of the pre-gel droplets during their descent. A novel type of emulsion gel bead composed of a poly(ethylene glycol) methyl ether acrylate hydrogel and di-n-hexylsulfide as an extractant was developed. The size of the emulsion gel beads was controlled by adjusting the gas flow rate. The emulsion gel beads successfully adsorbed Pd(II) ions that were used as a model metal.     

百重七含泥沙原油破乳脱水研究

克拉玛依油田百重七稠油处理站原油乳状液中含有大量泥砂,泥沙体积含量0.6‰～1‰,给原油脱水造成困难。本文以百重七原油处理站所处理的综合原油为研究对象,研制出破乳脱水用的KXDS破乳剂;同时考察了影响原油破乳脱水的几个因素,确定出最佳破乳温度和破乳剂最佳加量。KXDS破乳剂应用于现场后,破乳剂用量由120 mg/kg降低到80 mg/kg,破乳脱水温度由85℃降低到65℃,脱后原油达到外输优质标准,污水水质达标。     

褐铁型高锰红土矿微波预处理-酸浸提取镍钴

以褐铁型高锰红土矿为研究对象,采用微波预处理-酸浸工艺提取Ni、Co。对矿样物相组成及Ni、Co、Fe、Mn等主要元素赋存状态进行X射线衍射（XRD）和电子探针（EPMA）表征,研究常压条件下硫酸浓度、浸出时间、浸出温度等因素对微波预处理矿样中Ni、Co浸出效果的影响。结果表明：矿样中镍钴品位较高但物相结构复杂,Ni主要与Mn以NiMn₃O₇?3H₂O形式赋存,Co伴生于针铁矿和碱式氧化锰中;在最优浸出条件下,即硫酸浓度300g/L、浸出时间5h、浸出温度90℃、液固比6∶1（以mL/g计）、搅拌速度280r/min,Ni、Co浸出率分别达到95.4%和97.1%,与相同浸出条件下未经微波处理的矿样相比,Ni、Co浸出率分别提高了69.4%和70.1%,实现镍钴的高效浸出;对比微波处理前后矿样XRD图谱,发现微波作用下矿物中Ni、Fe、Mn等物相结构出现明显转变,利于Ni、Co酸浸反应。