Electrocoagulation/Electroflotation Process for Removal of Organics and Microplastics in Laundry Wastewater

In the present research, laundry wastewater treatment is studied using the electrocoagulation/electroflotation process. For the optimization of treatment conditions such as electrode type (Al–Al, Al–Fe, Fe–Fe, and Fe–Al), initial pH (5–9), current (0.54–2.16 A), and application time (15–60 min), response surface methodology is used. Removal efficiencies of chemical oxygen demand (COD), color, anionic surfactant, microplastic, and phosphate are studied. It is determined that the most effective removal is obtained with 2.16 A current, pH 9, and 60 min reaction time using Fe–Al electrode. Here, 91%, 94%, 100%, and 98% removal efficiencies are achieved for COD, surfactant, color, and microplastic, respectively. The operating cost of the combined process is calculated as $1.32 m^?3 for the optimum removal parameters. The adsorption kinetics study shows that the removal follows second‐order kinetics. The laboratory‐scale test results indicate that the electrocoagulation/electroflotation process is feasible for the treatment of laundry wastewater.     

S, C, O, H Isotope Data and Noble Gas Studies of the Maoniuping LREE Deposit, Sichuan Province, China： A Mantle Connection for Mineralization

The Maoniuping REE deposit, located about 22 km to the southwest of Mianning, Sichuan Province, is the second largest light REE deposit in China, subsequent to the Bayan Obo Fe-Nb-REE deposit in the Inner Mongolia Autonomous Region. Tectonically, it is located in the transitional zone between the Panxi rift and the Longmenshan-Jinpingshan orogenic zone. It is a carbonatite vein-type deposit hosted in alkaline complex rocks. The bastnaesite-barite, bastnaesite-calcite, and bastnaesite-microcline lodes are the main three types of REE ore lodes. Among these, the first lode is distributed most extensively and its REE mineralization is the strongest. Theδ34Sv-CDT values of the barites in the ore of the deposit vary in a narrow range of +5.0 to +5.1‰in the bastnaesite-calcite lode and +3.3 to +5.9‰in the bastnaesite-barite lode, showing the isotopic characteristics of magma-derived sulfur. Theδ13Cv-PDB values and theδ518OV-SMOW values in the bastnaesite-calcite lode range from -3.9 to -6.9‰and from +7.3 to +9.7‰, respectively, which fall into the range of "primary carbonatites", showing that carbon and oxygen in the ores of the Maoniuping deposit were derived mainly from a deep source. Theδ13Cv-PDB values of fluid inclusions vary from -3.0 to -5.6‰, with -3.0 to -4.0‰in the bastnaesite-calcite lode and -3.0 to -5.6‰in the bastnaesite-barite lode, which show characteristics of mantle-derived carbon. TheδDv-SMOW values of fluid inclusions range from -57 to -88‰, with -63 to -86‰in the bastnaesite-calcite lode and -57 to -88‰in the bastnaesite-barite lode, which show characteristics of mantle-derived hydrogen. Theδ18OH2OV-SMOW values vary from +7.4 to +8.6‰in the bastnaesite calcite lode, and +6.7 to +7.8‰in the bastnaesite-barite lode, almost overlapping the range of +5.5 to +9.5‰for magmatic water. The 4He content, R/Ra ratios are (13.95 to 119.58×10-6 (cm3/g)STP and 0.02 to 0.11, respectively, and 40Ar/36Ar is 313±1 to 437±2. Considering the 4He increase caused by high contents of radioactive elements, a mantle-derived fluid probably exists in the inclusions in the fluorite, calcite and bastnaesite samples. The Maoniuping deposit and its associated carbonatite-alkaline complex were formed in 40.3 to 12.2 Ma according to K-Ar and U-Pb data. All these data suggest that large quantities of mantle fluids were involved in the metallogenic process of the Maoniuping REE deposit through a fault system.     

切磨过程中花岗石材料去除机理研究

深入理解切磨过程中花岗石材料的去除机理是优化加工设备，加工工具以及加工参数的基础。本文研究了花岗石的断口表面、锯切表面、粗磨表面以及精磨表面形貌特征，并结合切磨过程中临界载荷、单颗金刚石磨粒所承受的切削力以及比能特征，对加工表面形成机理进行了分析。研究表明，材料的去除机理与单颗磨粒的最大切削厚度直接相关。随着单颗金刚石磨粒最大切削厚度的减小、花岗石的去除方式也逐渐由脆性断裂为主转为塑性流变为主。由于不同的材料去除机制对应不同的能量消耗，可以通过调节单颗磨粒的最大切削厚度控制材料的去除方式，进而控制能量消耗。因此，均匀的磨粒出露高度对于控制切磨过程中材料的去除机理和优化加工过程具有重要意义。     

Adjusting stream-sediment geochemical maps in the Austrian Bohemian Massif by analysis of variance

The Austrian portion of the Bohemian Massif is a Precambrian terrane composed mostly of highly metamorphosed rocks intruded by a series of granitoids that are petrographically similar. Rocks are exposed poorly and the subtle variations in rock type are difficult to map in the field. A detailed geochemical survey of stream sediments in this region has been conducted and included as part of the Geochemischer Atlas der Republik Österreich,and the variations in stream sediment composition may help refine the geological interpretation. In an earlier study, multivariate analysis of variance (MANOVA) was applied to the stream-sediment data in order to minimize unwanted sampling variation and emphasize relationships between stream sediments and rock types in sample catchment areas. The estimated coefficients were used successfully to correct for the sampling effects throughout most of the region, but also introduced an overcorrection in some areas that seems to result from consistent but subtle differences in composition of specific rock types. By expanding the model to include an additional factor reflecting the presence of a major tectonic unit, the Rohrbach block, the overcorrection is removed. This iterative process simultaneously refines both the geochemical map by removing extraneous variation and the geological map by suggesting a more detailed classification of rock types.     

不同碳源强化地下水中生物脱氮模拟试验研究

地下水中NO3^-N污染是普遍存在的环境问题,生物脱氮作用是去除该污染的主要机制,而生物脱氮菌群和营养碳源又是这种作用进行的主要限制性因子,该文应用这一理论将人工接种驯化并优势培养制备的生物脱氮菌剂,分别与不同种类不同配入量比的营养碳源物质一起施用,进行系列污染水体的生物脱氮模拟试验研究,以确定用于治理地下水中NO3－N污染的微生物菌剂和促进生物脱氮作用的营养碳源种类及其最佳配入量比值,探索修复治理地下水中大面积NO3－N污染的方法。     

大口径瓦斯地质孔钻探技术

运用非平衡钻探工艺理论，对煤矿瓦斯地层进行大口径钻孔的钻探，使目标层富集的高压瓦斯经抽放后得到释压，确保煤矿安全生产。在针对小构造带形成的角砾岩、松散煤层、不稳定地层等瓦斯地质条件下，采用中压风作为冲洗介质进行钻探中所存在的问题，重新设计了新型的钻具级配、正反向一体化钻头等，并且对风介质的排渣机理进行了阐述和分析。同时，就实践中遇到的问题和解决方法进行了总结。     

Bromide removal and recovery with layered double hydroxides as an adsorbent

Grignard regents have been applied extensively in chemical industry, especially in pharmacy. A mass of bromide-containing wastewater was produced after reaction, and ozonation of these organic contaminants can produce bromate and other brominated pollutants. The US Environmental Protection Agency （EPA） has established a maximum contaminant level of 10 μg/L for bromate in finished water. Therefore, it is necessary and significant to remove the DBP （disinfection by-products） precursor - bromide. On the other hand, since the bromine is a valuable element, recovery of it from wastewater is significant. Bromide removal is important to control DBP （disinfection by-products） contaminant and an ion exchange process is one of several treatment processes for this purpose. Layered double hydroxides （LDHs） are useful as adsorbents for bromide removal because of theft ion exchange properties. In this study, the adsorption properties of LDHs for bromide and the method of regeneration of this material were examined. It has been found that the LDHs with Mg/Al molar ratio of 2 represented the highest capacity to remove bromide ion from aqueous solution at pH 6.0. The equilibrium isotherms of uptake of bromide by CLDH were well fitted by the Langmuir equation. Bromide adsorbed on the LDHs was effectively desorbed at 30% Na2CO3 solution and the LDHs were regenerated at the same time. The regenerated LDHs could be reused repeatedly for the bromide removal. Bromide in the exhausted desorption solution was recovered as bromine by oxidation using Cl2.     

Optimization strategies for sediment reduction practices on roads in steep,forested terrain

Many forested steeplands in the western United States display a legacy of disturbances due to timber harvest, mining or wildfires, for example. Such disturbances have caused accelerated hillslope erosion, leading to increased sedimentation in fish‐bearing streams. Several restoration techniques have been implemented to address these problems in mountain catchments, many of which involve the removal of abandoned roads and re‐establishing drainage networks across road prisms. With limited restoration funds to be applied across large catchments, land managers are faced with deciding which areas and problems should be treated first, and by which technique, in order to design the most effective and cost‐effective sediment reduction strategy. Currently most restoration is conducted on a site‐specific scale according to uniform treatment policies. To create catchment‐scale policies for restoration, we developed two optimization models – dynamic programming and genetic algorithms – to determine the most cost‐effective treatment level for roads and stream crossings in a pilot study basin with approximately 700 road segments and crossings. These models considered the trade‐offs between the cost and effectiveness of different restoration strategies to minimize the predicted erosion from all forest roads within a catchment, while meeting a specified budget constraint. The optimal sediment reduction strategies developed by these models performed much better than two strategies of uniform erosion control which are commonly applied to road erosion problems by land managers, with sediment savings increased by an additional 48 to 80 per cent. These optimization models can be used to formulate the most cost‐effective restoration policy for sediment reduction on a catchment scale. Thus, cost savings can be applied to further restoration work within the catchment. Nevertheless, the models are based on erosion rates measured on past restoration sites, and need to be updated as additional monitoring studies evaluate long‐term basin response to erosion control treatments. Copyright © 2006 John Wiley & Sons, Ltd.     

增厚大陆岩石层热边界层对流剥离的数值模拟

用数值模拟方法模拟了增厚大陆岩石层热边界层被对流地幔剥离并为软流层物质替代的动力学过程．结果表明,在初始温度分层分布、侧向均匀但存在微小热扰动的流场中,80km厚的增厚岩石层热边界层约需60Ma才能被完全剥离,剥离的速率微弱地依赖扰动的强度;在已建立好的流场中,同样厚度的增厚热边界层只需约10Ma就可被剥离．模拟结果暗示青藏高原地壳及岩石层在岩石层增厚和剥离以前就很热,其下伏地馒中可能已存在建立好的上地幔小尺度对流系统,而该尺度的对流系统很可能是由特提斯海洋岩石圈俯冲和消减诱发的     

Analysis of oil lens removal by extraction through a seepage face

Removal of LNAPL (oil) from an aquifer is described using a multiphase flow model. At the well boundary seepage face conditions are imposed. These conditions are implemented in a numerical model and withdrawal in a twodimensional domain is simulated for two different geometries of the oil lens and for varied values of the physical parameters. Assuming vertical equilibrium, the oil flow equation is reduced by vertical integration. The well boundary condition is approximated by imposing zero oil lens thickness. Similarity solutions of the reduced equations for the two geometries show good agreement with the numerical results in most cases.