放射性轻微污染物料清洁解控管理实践和思考

通过对IAEA和国内外关于放射性轻微污染物料清洁解控管理和实践的分析,对国内核电厂运行产生的放射性污染物料清洁解控管理存在的问题进行了思考并在此基础上提出了改进建议。

核电站放射性轻微污染物料的清洁解控

为了实现电站放射性废物最小化管理,对其产生的轻微放射性污染物料实施清洁解控是有效途径之一。在根据国内外相关标准和分析国内核电站轻微放射性污染物料源项特性的基础上,提出了适于我国核电站产生的轻微放射性污染物料的清洁解控流程。

核电厂轻微污染物料清洁解控流程标准化探讨

核电厂运行和维修时产生的放射性轻微污染物料需要解控。为保障未来清洁解控工作顺利实施,提高清洁解控工作的质量和效率,调研阐述了核电厂清洁解控物料类型、解控限值及解控方法,对已有核电厂轻微污染物料清洁解控流程和实施步骤进行了梳理分析,从便于实施解控的角度提出了清洁解控标准流程优化建议。

相关因子法在轻微污染物料解控中的应用

介绍了相关因子法在轻微放射性污染物料实施解控中的应用。应用结果表明,相关因子法在解控监测中具有快速、准确性高的优点,可大大提高解控监测效率。

核设施退役产生的污染物料的再循环再利用

简要阐述了核设施退役过程产生的主要污染物料)))金属和混凝土的再循环和再利用情况,包括染物料的产生情况、再循环再利用途径、再循环再利用可参考的标准,以及几种污染物料的再循环再利用技术,以期对我国今后核设施退役产生的污染物料的管理提供技术支持。

宁德核电站轻微污染物料清洁解控前的准备工作实践

为了实现核电站放射性废物最小化,宁德核电站根据相关标准制定了轻微污染物料清洁解控策略及管理操作程序,并对APG废树脂、通风滤芯框架及个人防护用品进行了分类管理及测量,为实施解控做准备。

核电站放射性轻微污染物料的清洁解控

当前我国核电站运行中放射性轻微污染物料的积存不利于放射性废物的最小化,因此必须对放射性轻微污染物料采取有效的解控处理进行深入的探究.

Impacts of Agricultural Non-point Pollution on Water-source Area in Songhua Dam

[Objective] The aim was to research impacts of agricultural non-point pol- lution on water-source region in Songhua Dam, laying foundation for control of water pollution and scientific protection of water-source region. [Method] Water in Muyang River, lengshui River and Zizania aquatica region were sampled to measure content of pollutants in water and conclude relation between water contamination and agri- cultural non-point pollution to find the major cause of pollution. [Result] Organic pollu- tant in Muyang River was higher; N and P contents in Lengshui River were higher; the measured indices in Zizania aquatica region excessively exceeded related stan- dard. [Conclusion] The chemical fertilizers and pesticides are the toxic materials lead- ing to water contamination and constitute a major cause of pollution in Songhua Dam water-source region. Agricultural non-point pollution should be controlled in a scientific way.

Numerical simulations of water flow and contaminants transport near mining wastes disposed in a fractured rock mass

A numerical tool, called Hydro-Geosphere, was used to simulate unsaturated water flow and contaminants migration around an open pit filled with mining wastes. Numerical simulations had been carried out to assess the influence of various factors on water flow and solute transport in and around the surface openings including recharge, properties of the waste material and presence of fractures in the surrounding rock mass. The effect of the regional hydraulic gradient was also investigated. The analyses were conducted by simulating various 2D cases using experimentally obtained material properties and controlled boundary conditions. The effects of the hydrogeological properties of the filling material(i.e., water retention curve and hydraulic conductivity function), fracture network characteristics and conductivity of the joints were assessed. The results illustrate that fractures control water flow and contaminants transport around the waste disposal area. A fracture network can desaturate the system and improve the regional gradient effect.

Transfer of Heavy Metal Contaminants from Animal Feed to Animal Products

Study was conducted to assess the possible transfer of heavy metals from livestock feeds to animal products. In experiment-l, samples （n = 503） collected from conventional farms in Central Greece were analysed for heavy metal Copper （Cu）, Zinc （Zn）, Cadmium （Cd）, Lead （Pb）, Nickel （Ni） and Chromium （Cr） contents in muscle tissues, livers, kidneys, excremental and basic mixtures in livestock such as cows and sheep. Results showed that transfer of heavy metal contaminants from feed to animal products fluctuated below the permissible risk levels. In experiment 2, samples （n = 440） of feedstuffs used in different feeding regimens and seasons at different livestock farms [sheep （n = 140）, dairy cows （n = 180）, pigs （n = 120）] were collected. Results showed that relatively high concentration of Cu in the excrements of pigs （155 ＋ 9.13） and Zn in the excrements of sheep （144.56 ＋ 5.78） are explained by the use of Cu in the diet of developing piglets and sheep. Ovine showed higher concentration ofNi, Cr, and Pb in their excrements, while, the concentration of heavy metals in forages was under the allowed range to the EU legislation.

Sono-assisted preparation of magnetic ferroferric oxide/graphene oxide nanoparticles and application on dye removal

A simple ultrasound-assisted co-precipitation method was developed to prepare ferroferric oxide/graphene oxide magnetic nanoparticles(Fe_3O_4/CO MNPs).The hysteresis loop of Fe_3O_4/GO MNPs demonstrated that the sample was typical of superparamagnetic material.The samples were characterized by transmission electron microscope,and it is found that the particles are of small size.The Fe_3O_4/GO MNPs were further used as an adsorbent to remove Rhodamine B.The effects of initial pH of the solution,the dosage of adsorbent,temperature,contact time and the presence of interfering dyes on adsorption performance were investigated as well.The adsorption equilibrium and kinetics data were fitted well with the Freundlich isotherm and the pseudosecond-order kinetic model respectively.The adsorption process followed intra-particle diffusion model with more than one process affecting the adsorption of Rhodamine B.And the adsorption process was endothermic in nature.Furthermore,the magnetic composite with a high adsorption capacity of Rhodamine B could be effectively and simply separated using an external magnetic field.And the used particles could be regenerated and recycled easily.The magnetic composite could find potential applications for the removal of dye pollutants.

Peroxymonosulfate activation by Mn_3O_4/metal-organic framework for degradation of refractory aqueous organic pollutant rhodamine B

An environmentally friendly Mn‐oxide‐supported metal‐organic framework(MOF),Mn3O4/ZIF‐8,was successfully prepared using a facile solvothermal method,with a formation mechanism proposed.The composite was characterized using X‐ray diffraction,scanning electron microscopy,transmission electron microscopy,X‐ray photoelectron microscopy,and Fourier‐transform infrared spectroscopy.After characterization,the MOF was used to activate peroxymonosulfate(PMS)for degradation of the refractory pollutant rhodamine B(RhB)in water.The composite prepared at a0.5:1mass ratio of Mn3O4to ZIF‐8possessed the highest catalytic activity with negligible Mn leaching.The maximum RhB degradation of approximately98%was achieved at0.4g/L0.5‐Mn/ZIF‐120,0.3g/L PMS,and10mg/L initial RhB concentration at a reaction temperature of23°C.The RhB degradation followed first‐order kinetics and was accelerated with increased0.5‐Mn/ZIF‐120and PMS dosages,decreased initial RhB concentration,and increased reaction temperature.Moreover,quenching tests indicated that?OH was the predominant radical involved in the RhB degradation;the?OH mainly originated from SO4??and,hence,PMS.Mn3O4/ZIF‐8also displayed good reusability for RhB degradation in the presence of PMS over five runs,with a RhB degradation efficiency of more than96%and Mn leaching of less than5%for each run.Based on these findings,a RhB degradation mechanism was proposed.

Execution of Measurements for Determining the Parameters Affecting the Thermochemical Treatment of Brine Treated Biomass and the Adsorption of Dyes

Brine is a solution of salt （usually sodium chloride） in water. In different contexts, brine may refer to salt solutions ranging from about 3.5% （a typical concentration of seawater, or the lower end of solutions used for brining foods） up to about 26% （a typical saturated solution, depending on temperature）. Adsorption onto activated carbon is the most widespread technology for the removal of pollutants from water and wastewaters. In this study, continuous fixed-bed-column systems were investigated. The adsorbents which authors use are： spruce （Picea abies） untreated, spruce modified by autohydrolysis. The column systems were filed with biomass at various initial dye concentrations, flow rates and bed-depths. The column kinetics of MB （Methylene Blue） adsorption on spruce （Picea abies） untreated, spruce modified by autohydrolysis was simulated. Economies arise when the facility that can use such adsorption materials is near a source of a lignocellulosic waste as agricultural residues, thus saving transportation cost and contributing to industrial ecology at local level.

Green synthesis of nickel nanoparticles using Ocimum sanctum and their application in dye and pollutant adsorption

Nickel nanoparticles as an eco-friendly adsorbent was biosynthesized using Ocimum sanctum leaf extract. The physiochemical properties of green synthesized nickel nanoparticles(Ni Gs) were characterized by UV–Vis spectroscopy(UV–Vis), Fourier Transform Infrared Spectroscopy(FTIR), X-ray diffraction(XRD), Scanning Electron Microscope(SEM) and Transmission Electron Microscope(TEM). Ni Gs were used as adsorbent for the removal of dyes such as crystal violet(CV), eosin Y(EY), orange II(OR) and anionic pollutant nitrate(NO3-), sulfate(SO42-) from aqueous solution. Adsorption capacity of Ni Gs was examined in batch modes at different p H, contact time, Ni G dosage, initial dye and pollutant concentration. The adsorption process was p H dependent and the adsorption capacity increased with increase in contact time and with that of Ni G dosage, whereas the adsorption capacity decreased at higher concentrations of dyes and pollutants. Maximum percentage removal of dyes and pollutants were observed at 40, 20,30, 10 and 10 mg·L-1initial concentration of CV, EY, OR, NO3-and SO42-respectively. The maximum adsorption capacities in Langmuir isotherm were found to be 0.454, 0.615, 0.273, 0.795 and 0.645 mg·g-1at p H 8, 3, 3, 7and 7 for CV, EY, OR, NO3-and SO42-respectively. The higher coef ficients of correlation in Langmuir isotherm suggested monolayer adsorption. The mean energies(E), 2.23, 3.53, 2.50, 5.00 and 3.16 k J·mol-1for CV, EY, OR, NO3-and SO42-respectively, calculated from the Dubinin–Radushkevich isotherm showed physical adsorption of adsorbate onto Ni Gs. Adsorption kinetics data was better fitted to pseudo-second-order kinetics with R2 N 0.870 for all dyes and pollutants. Ni Gs were found to be an effective adsorbent for the removal of dyes and pollutants from aqueous solution and can be applied to treat textile and tannery ef fluents.

Wastewater Treatment for Removal of Recalcitrant Compounds：A Hybrid Process for Decolorization and Biodegradation of Dyes

While conventional wastewater treatments for urban effluents are fairly routine and have proved highly effective,industrial wastewater requires more complex and specific treatments.This paper provides a technological strategy for removal of recalcitrant contaminants based on a hybrid treatment system.The model effluent containing a binary mixture of synthetic dyes is treated by a combination of a preliminary physicochemical stage followed by a biological stage based on ligninolytic enzymes produced by Phanerochaete chrysosporium.This proposal includes biosorption onto peat as pretreatment,which decreases the volume and concentration to be treated in the biological reactor,thereby obtaining a completely decolorized effluent.The treated wastewater can therefore be reused in the dyeing baths with the consequent saving of water resources.

Eggshell as a Source of Novel Bioactive Molecules

This review will focus on the more abundant eggshell specific matrix proteins localized in the chicken eggshell （cuticle layer eggshell matrix and shell membranes） that are involved in eggshell mineralization and protecting the egg against microbial contamination, including ovocalyxin-36, ovocleidin-17, ovocalyxin-32 and ovocalyxin-25. Further understanding of these proteins and their mechanisms in egg defence could lead to the development of novel neutraceuticals for human health, additives to animal feed for healthy flocks, or enhanced eggs for human consumption.

Solid oxide fuel cell:materials,technology and application

Solid oxide fuel cells (SOFCs) offer a clean, pollution-free technology for the electrochemical conversion of chemical energy of hydrocarbon fuels into electricity. Many programs are being initiated in the United States, Europe, Japan and so on. The funding for SOFC development worldwide has risen dramatically and this trend is expected to continue for at least the next decades. These development programs are also investigating wider applications of SOFCs in stationary, residential, transportation and military sectors. Finally, it is summarized the key materials and fabrication processes of SOFC in this paper.

Comparison between Current Technologies for the Best Choice of Thermoelectric Plant with Coal or Uranium

Between the alternative sources available for the electricity production, still lacks reliability for the production in base units. For the electricity production from 500 MW to 1,000 MW or more, the coal-fired thermal and nuclear power plants with uranium have proved competitive and with a high level of reliability and maturation, besides presenting the fuel supply security. This paper presents an analysis of technical feasibility for the choice of the best technology for generating electricity on a large scale, based on coal-fired thermal or nuclear power plant using uranium. This paper takes in account the availability of fuel sources, investments costs, thermal power generation systems, pollutants emission and mitigation technologies, global efficiency, fuel consumption, costs of electricity, construction time and an average lifespan of the installation. Thus the analysis allows the most rational choice of technology for the production of electricity with lower electricity costs and lower COz emissions.

Effect of Cement Dust Pollution on the Yield and Quality of Ficuscarica L. Fruits

The present study was carried out on Ficuscarica L. cultivated in the northwestern desert of Egypt. Plant materials （leaves and fruits） were collected from three polluted locations at a distance of 500-700, 1,000-1,250 and 3,000-3,500 m respectively away from the cement factory at EI-Hammam city, and a location of relatively clean air considered a control at 5,000-6,000 m away from this factory. The deposit cement dust washed from the surface leaf area of plant study was found to be 4.96, 4.21, 0.51 and 0.29 lag/cm2 at the four locations, respectively. Cement in more polluted locations increased mortality of young branches leading to a reduction in the height and yield of fig trees. The deposition of cement pollutants tothe loamy sandy soil of the present study alteredsoil chemical characteristics. The results showed that, biomass of fruits/tree, number of branches/tree and number of fruits/branch in polluted locations were significantly lower than those of the control one. Cement dust decreased leaf total chlorophyll content leading to a reduction in the economic yield （up to 50%）. Metabolic constituents （carbohydrates, proteins, amino acid and proline） and essential elements （Fe, Mg, Na, Ca, and K） were studied in two types of fruits on fig trees （mature and premature）. Thallium as a toxic metal was predicted in edible mature fruits, and the results showed that the concentration of thallium parts per billion （ppb） in polluted locations was significantly higher than those of the control one. The results revealed that fruits of fig plants at polluted sites showed quantitative and qualitative deteriorations.