Sorption Preconcentration and Determination of Cobalt in Industrial Solutions by Diffuse Reflection Spectroscopy Method

Cobalt and its compounds have a broad field of application in Russian industries, being essential raw materials for metallurgy, medicine, and agriculture. That is why the production of cobalt is one of the key industries in Russia. Cobalt is produced from mineral raw materials as well as from secondary raw materials (for example, after processing of spent catalysts of oil refinery). It can also be obtained as a by‐product of nickel, manganese, and some other metals processing. That is the reason why the solutions of Ni and Mn industries contain up to 50 g/L of cobalt. obalt compounds are harmful for men’s heart, bloodvessel system, and thyroid gland. This fact explains the importance of the monitoring of cobalt concentrations in natural water and sewages. This task can be effectively achieved using the analytical sorption technique. The present work is focused on the preconcentration of cobalt and its determination by means of diffuse reflection spectroscopy. The preconcentration of cobalt was carried out using the macronetwork cation exchangers KB‐2M and KB‐2‐3T synthesized on the basis of methyl acrylate and long‐chain cross‐linking agents copolymers. Based on these collectors, a cobalt determination method in industrial solutions was worked out using solid‐phase spectroscopy. The colored surface compound to be determined was obtained by a preceding cobalt sorption on the resin and by subsequent treatment of the concentrate obtained with definite amount of nitroso‐R‐salt. The Co calibration curve is linear in the concentration range of 0.05...0.50 mg/L Co (sample volume is 50.0 mL) and the detection limit is 0.02 mg/L (1 μg absolute).     

离子色谱法测定地下水中有机氮

本文探讨了K_2S_2O_8氧化离子色谱法测定有机氮的实验条件,考察了淋洗剂离子价态及淋洗剂总离子强度对低浓度NO_3~-与高浓度SO_4~2-分离的影响;测定了11种含氮有机化台物有机氮的回收率。本法测定地下水中有机氮的结果与经典蒸馏法结果较为一致,具有操作简便、快速、准确,效率高的特点。     

NaCl型油田水中I^-的离子选择电极法测定

采用了NaCl溶液为离子强度调节剂(TISAB),离子选择电极法测定NaCl型油田水中I-离子的含量,并对该方法进行了测定条件实验的研究。标准曲线在7.94×10-6～1.00 mol/L范围内呈良好的线形关系,相关系数R2=0.999 5,平均回收率为98.9%,RSD(n=6)=1.0%,实验结果表明,该方法测定NaCl型油田水中的I-简便、快速、准确。     

A novel high-resolution small ion spectrometer to study ion nucleation of aerosols in ambient indoor and outdoor air

An electrically based ion spectrometer is described, capable of measuring particle sizes and mobilities from molecular ions (small ions) to aerosol particles across a size range of 0.4 to 30 nm in diameter. It consists of a single cylindrical capacitor divided into three electrically insulated sections. The current arriving at the central section is measured by an electrometer and represents the ion flux over a known range of mobilities determined by the applied voltage. The applied voltage is scanned in steps to measure the ion fluxes over a large number of overlapping mobility ranges. The recorded signal and the response function of the instrument are unfolded using a maximum entropy procedure to give a high-resolution measured mobility spectrum. The maximum entropy approach offers a considerable improvement over traditional aspiration collectors and can approach the resolution of a drift tube system. In this way, the spectrometer successfully overcomes the diffusion limit to small ion resolution. Illustrative spectra are shown, demonstrating for the first time the presence of some resolved structure within the small ion spectrum at the highest mobilities. It is demonstrated that the actual mobility spectrum of small ions falls in the range 0.8–2.0 × 10⁻⁴ m² V⁻¹ s⁻¹. This represents a narrower range than that previously measured which is attributed to improved spectral resolution in the present work.     

Physiological Responses of Halophyte Suaeda salsa to Water Table and Salt Stresses in Coastal Wetland of Yellow River Delta

Soil salinity and waterlogging are two major environmental problems in estuarine wetlands. The objective of this study was to investigate the effects of salt stress, water table, and their combination on growth, chlorophyll content, antioxidant system, and ion accumulation in Suaeda salsa plant, which is the pioneer plant in coastal wetland of the Yellow River Delta (YRD). The results showed that plant height, number of branches, and biomass were significantly affected by water table and salt stress. With enhanced salt stress, the ratio of leaf to total biomass increased and the ratio of root to total biomass decreased. The contents of Chl‐a, ‐b, Chl‐a + b, and carotenoids (Car) decreased significantly with increasing soil salinity and the water table level. Salt stress enhanced the activity of superoxide dismutase (SOD) and catalase (CAT), but reduced the content of protein. With the lowering water table level, the activity of CAT and protein content increased, and activity of SOD decreased. Na⁺ and Cl^? content were up‐regulated with increasing salt stress (NaCl), whereas, the contents of other cations (K⁺, Ca²⁺, and Mg²⁺) and anions ( and ) were decreased. In summary, the results indicated that the S. salsa plants could adapt to the adverse soil environments through modifying their growth and physiology status at the highly saline and intertidal zone, such as the YRD estuarine wetlands, and also could be used as a bio‐reclamation plant to decline the high salt in saline soils.     

Impact of post-mixing chemical reactions on the major ion chemistry of bulk meltwaters draining the haut glacier d'arolla,valais, Switzerland

Until now, alpine glacial meltwaters have been assumed to consist of two components, dilute quickflow and concentrated delayed flow, the mixing of which has been regarded as chemically conservative for the major dissolved ions and electrical conductivity. Dye tracing results suggest that this two-component model adequately represents the sub-glacial hydrology of the Haut Glacier d'Arolla, Switzerland. However, laboratory dissolution experiments in which various concentrations of glacial rock flour are placed in dilute solutions show that this rock flour is highly reactive and suggest that bulk meltwaters may acquire significant amounts of solute through rapid chemical reactions with suspended sediment which occur after mixing of the two components. This view is supported by detailed analysis of variations in the hydrochemistry of meltwaters draining from the Haut Glacier d'Arolla over three diurnal cycles during the 1989 melt season. Variations in the composition of bulk meltwaters are controlled by two main factors: dilution of the delayed flow component by quickflow, and the extent of post-mixing reactions. The latter depends on the suspended sediment concentration in bulk meltwaters and on the duration of contact between these waters and suspended sediment. Seasonal changes in the magnitude of these factors result in changes in the character and causes of diurnal variations in meltwater chemistry. In June, these variations reflect discharge-related variations in residence time within a distributed subglacial drainage system; in July, when a channelized drainage system exists beneath the lower glacier, they primarily reflect the dilution of delayed flow by quickflow; in August, when suspended sediment concentrations are particularly high, they reflect varying degrees of solute acquisition by post-mixing reactions with suspended sediment that take place in arterial channels at the glacier bed.     

离子色谱法同时测定天然碱矿中氯离子和硫酸根离子

通过测定氯离子和硫酸根离子可以确定天然碱矿中石盐和芒硝的含量,目前分析方法比较少,且流程冗长,容易污染,生产效率低。本文建立了离子色谱-抑制电导法测定天然碱矿中氯离子和硫酸根的分析方法。样品中水溶性阴离子经热水溶解进入溶液,以30 mmol/L氢氧化钾溶液作为淋洗液,利用AG19阴离子保护柱、AS19阴离子分离柱分离样品中的氯和硫酸根,CRD 200碳酸盐消除装置去除了碳酸根的干扰。方法检出限氯离子为0.01 mg/L,硫酸根为0.02 mg/L;加标回收率为100.9%～104.1%;精密度(RSD,n=10)小于2.5%。实际样品分析结果与滴定法的测定值基本吻合。本法操作简单,重现性好,灵敏度高,结果可靠,不受样品复杂组分及形成缓冲溶液体系的干扰,很好地解决了传统方法费时、耗材、不能同时测定氯离子和硫酸根的问题。     

On the peak level of tearing instability in an ion-scale current sheet: The effects of ion temperature anisotropy

We have systematically surveyed the effects of the ion temperature anisotropy on the peak reconnected flux level of the tearing instability excited in a thick current sheet (its half-thickness D equal to the ion inertial length). A series of two- and three-dimensional (2-D and 3-D) simulations have been performed for a magnetotail-like situation, where the ion perpendicular temperature is fixed to balance the magnetic pressure of the lobe while the ion parallel temperature can be varied to give rise to the temperature anisotropy α_i=T_i,perp/T_i,para. Focusing on the behavior of the fastest growing mode (wavelength λ=12D), the results are summarized as follows: (1) The peak levels are larger when the initial α_i is larger and lobe reconnection is obtained only when α_i>1.5. (2) 3-D effects do speed-up the reconnection process but do not change the peak level substantially. (3) The time-scale of gas pressure build-up at the center of magnetic islands relative to the time-scale of reconnected flux growth is identified to be the key issue in determining the peak level. Based on these results for the fastest growing mode with λ=12D, discussion is given on the larger-scale development, that is, what happens when longer wavelength modes are allowed to develop.     

Foreshock cavities and internal foreshock boundaries

We present two case studies of cluster encounters with foreshock cavities. For one event, we are able, for the first time, to accurately relate the observation of a foreshock cavity to the measured position of the bow shock. This allows us to compute the shock angle, a vital parameter in models of foreshock cavity formation, with greater confidence than any previous study. This cavity appears to be elongated along the magnetic field and we use the multispacecraft nature of the Cluster mission to constrain its field-parallel and -perpendicular extent. We show that this event is embedded within a region of field-aligned ion beams. This is the first time a foreshock cavity has been shown to be surrounded by foreshock ion beams. A second foreshock cavity is associated with a small rotation in the interplanetary magnetic field (IMF). We show that this event appears on the boundary between an interval when the spacecraft were inside the ion foreshock, and an excursion upstream. This is the first report of a foreshock cavity observed during the traversal of the global foreshock. This second event has some features expected from the new Sibeck et al. (2008) model of cavities as brief encounters with a spatial boundary in the global foreshock.