Heavy metals in seawater: Effects on limpet pedal mucus production

Toxicological modification of molluscan mucus production has largely been ignored. This is probably due to an underestimation of the r le of mucus in molluscan physiology and its energetic cost. This paper reports that laboratory exposure to episodic doses of waterborne copper and zinc serve to reduce pedal mucus production by the common limpet Patella vulgata L. to about 60% of the unstressed rate. The metals are effective in this respect at concentrations as low as 10 μg l⁻¹, which in the case of zinc is below the current U.K. environmental quality standard. All metal doses reduced mucus production to the same level. This suggests a behavioural response of the limpet, limiting activity. The reduction in mucus production has important consequences both for limpet ecology and for the ways in which biological energy allocation and transformation are assessed.     

Adsorption character for removal Cu(II) by magnetic Cu(II) ion imprinted composite adsorbent

A novel magnetic Cu(II) ion imprinted composite adsorbent (Cu(II)-MICA) was synthesized, characterized and applied for the selective removal Cu(II) from aqueous solution in the batch system. The adsorption-desorption and selectivity characteristics were investigated. The maximum adsorption occurred at pH 5-6. The equilibrium time was 6.0h, and a pseudo-second-order model could best describe adsorption kinetics. The adsorption equilibrium data fit Langmuir isotherm equation well with a maximum adsorption capacity of 46.25mg/g and Langmuir adsorption equilibrium constant of 0.0956L/mg at 298K. Thermodynamic parameters analysis predicted an exothermic nature of adsorption and a spontaneous and favourable process that could be mainly governed by physisorption mechanism. The relative selectivity coefficients of Cu(II)-MICA for Cu(II)/Zn(II) and Cu(II)/Ni(II) were 2.31, 2.66 times greater than the magnetic non-imprinted composite adsorbent (MNICA). Results suggested that Cu(II)-MICA was a material of efficient, low-cost, convenient separation under magnetic field and could be reused five times with about 14% regeneration loss.     

Characteristics of industrial and laboratory meat and bone meal ashes and their potential applications

This paper reports the characterization of four meat and bone meal (MBM) ashes obtained from specific incineration (laboratory) and from co-incineration (industrial process). Three out of the four MBM ashes were mainly composed of calcium phosphates (hydroxyapatite and whitlockite). Their compositions (major and trace) were in the range for natural phosphate rocks. Trace element contents, including heavy metals, were below 0.6% and industrial ashes contained much more heavy metals than laboratory ash. The amounts of leached elements were low, especially for laboratory ash. According to the European classification of waste to be landfilled, the laboratory ash can be classified as an inert waste. Two industrial ashes are mostly inert. Only one ash is highly leachable and needs a stabilization treatment to be classified at least in the category of hazardous waste. It seems, from these results, that possibilities other than landfilling could be considered to give economic value to these ashes.     

Friction and Wear Behaviors of Nanostructured Metals

Nanostructured （ns） materials, i.e., polycrystalline materials with grain sizes in the nanometer regime （typically below 100 nm）, have drawn considerable attention in the past decades due to their unique properties such as high strength and hardness. Wear resistance of ns materials, one of the most important properties for engineering materials, has been extensively investigated in the past decades. Obvious differences have been identified in friction and wear behaviors Between the ns materials and their corresponding coarse-grained （cg） counterparts, consistently correlating with their unique structure characteristics and mechanical properties. On the other hand, the superior tribological properties of ns materials illustrate their potential applications under contact loads. The present overview will summarize the important progresses achieved on friction and wear behaviors of ns metallic materials, including ultrafine-grained （ufg） materials in recent years. Tribological properties and effects on friction and wear behaviors of ns materials will be discussed under different wear conditions including abrasive wear, sliding wear, and fretting wear. Their correlations with mechanical properties will be analyzed. Perspectives on development of this field will be highlighted as well.     

我国有色金属行业自主创新现状及研究对策

文章介绍了创新的概念、分类,对我国有色金属行业自主创新存在的优势及不足进行了分析,介绍了有色金属工业中长期科技发展规划（2006--2020）的目标,提出了自主创新总体对策及具体措施。     

分银渣中贵金属的回收

对分银渣中金、银等贵金属采用火法工艺处理,贵金属以单质形态富集。试验结果Au、Ag富集率≥95%。     

The Influence on Boundary Friction of the Permeability of Sintered Bronze

Components made of sintered bronze are often used in tribological systems. Examples of applications are self lubricated bearings, wet clutches and brakes and synchromesh components for manual gearboxes. The bronze material in these applications is often porous and permeable. However, the required level of permeability i.e., the ability for a fluid to flow inside the material varies widely for different applications. This implies the need to investigate if the permeability can influence the properties of a tribological system. Various studies have been performed in order to investigate the permeability of different materials but a possible relationship between permeability and boundary lubrication performance has not yet been thoroughly investigated. In this article this relationship has been investigated in a pin-on-disk apparatus for test specimens with a permeability that is well-defined. Materials with three different permeabilities were investigated together with non-permeable test specimens. The results indicate that permeability has a small influence on the friction coefficient when the tribological system is operating with good lubrication of the contact. The function of the tribological system when working under starved conditions is also investigated and a very clear relationship between permeability and the ability to cope up with starved running conditions is shown. This is explained in terms of the varying ability of the materials’ to store lubricant in pores. Non-porous test specimens were also tested as a comparison with the permeable test specimens in the investigation with starved running conditions . The results show that a material with high permeability works much better under starved running conditions than that with low permeability.     

Electrokinetic Remediation Modeling Incorporating Geochemical Effects

Electrokinetic remediation technology is one of the developing technologies that offers great promise for the cleanup of soils contaminated with heavy metals. However, the performance of an electrokinetic remediation system depends on the interaction of a complex set of interrelated system variables and parameters. Many of these interactions were addressed in this study by incorporating geochemical reactions into electrokinetic remediation modeling. A one-dimensional transport model was developed to predict the transport and speciation of heavy metals (chromium, nickel, and cadmium) in soil during electrokinetic remediation as a function of time and space. The model incorporates: (1) pH-dependent adsorption of contaminants to the soil surface; (2) sensitivity of soil surface potential and electroosmotic flow to the pore water properties; and (3) synergistic effects of multiple chemical species on electrokinetic remediation. The model considers that: (1) Electrical potential in the soil is constant with time; (2) surface complexation reactions are applicable in the highly concentrated clay suspensions; (3) the effect of temperature is negligible; and (4) dissolution of soil constituents is negligible. The predicted pH profiles, electroosmotic flow, and transport of chromium, nickel, and cadmium in kaolin soil during electrokinetic remediation were found to reasonably agree with the bench-scale electrokinetic experimental results. The predicted contaminant speciation and distribution (aqueous, adsorbed, and precipitated) allow for an understanding of the transport processes and chemical reactions that control electrokinetic remediation.