A biological oil adsorption filter

A new oil adsorption method called adsorption filtration (AF) has been developed. It is a technology where by oil residues can be cleaned from water by running it through a simple filter made from freeze treated, dried, milled and then fragmented plant material. By choosing suitable plants and fragmentation sizes it is possible to produce filters, which pass water but adsorb oil. The aim of this study was to investigate the possibilities of manufacturing oil adsorbing filter materials from reed canary grass (Phalaris arundinacea), flax (Linum usitatissimum L.) or hemp fibre (Cannabis sativa L.). The oil (80 ml) was mixed with de-ionised water (200 ml) and this mixture was filtered through 10 or 20 g adsorption filters. Fine spring harvested hemp fibre (diameter less than 1 mm) and reed canary grass fragments adsorb 2-4 g of oil per gram of adsorption material compared to 1-3 g of water. Adsorption filtration is thus a novel way of gathering spilled oil in shallow coastal waters before the oil reaches the shore.     

Wave overtopping and piling-up at permeable low crested structures

The paper aims at providing a simple model for evaluating piling-up, overtopping, filtration and rip currents for low crested structures. The model is essentially based on mass and momentum balance and on resistance laws that relate piling-up and mass fluxes. A procedure is suggested and validated against 2D and 3D experimental data. This procedure is innovative with respect to existing formulations since it applies both to emerged and submerged structures and it simultaneously accounts for structure permeability, return flow through gaps and dissipative effects.     

Removal of Cryptosporidium parvum Oocysts by Rapid Sand Filtration with Ballasted Flocculation‐Filtration and Intermediate Downwashes

A novel and efficient protocol optimising deep‐bed filtration of surface water was developed. The innovation lies in ballasted‐flocculation filtration and an intermediate downwash. The approach is based on the assumption that kaolin particles with a partial positive charge may adsorb onto the surface of C. parvum oocysts and neutralize their negative charge. Application of this technology enhanced removal of inorganic particles and Cryptosporidium parvum oocysts by approximately 30 % and shortened the ripening stage of the filtration process from 1 h to about 10 min.     

干扰井群渗透系数计算的简便公式

干扰井群渗透系数计算的简便,公式是依据雅可布公式,根据叠加原理建立的。克服了计算方法烦杂,需解诸多未知数和使用范围窄及图解法计算时人为的随意性。增加了计算结果的可靠性。     

Mechanisms and duration of non-tectonically assisted magma emplacement in the upper crust: The Black Mesa pluton, Henry Mountains, Utah

A new study of Black Mesa pluton (Henry Mountains, Colorado Plateau, Utah, USA) indicates that it is a classic example of a small upper-crustal pluton assembled over a few years by incremental amalgamation of discrete magma pulses. The results of our petrostructural study of the pluton interior allow us to constrain the geometry, kinematics and timing of the processes. The symmetric internal fabric is interpreted as an evidence for a feeding by below and not laterally. The observed rotation of the lineation, from WNW–ESE on the very top to NNE–SSW below, lead us to propose that the fabric at the base of the pluton is a record of magma infilling process, and the fabric at the very top is a record of the strain due to the relative movement between magma and wallrocks. A consequence is that except at the contact between pluton and wallrocks (top and margins), the stretching direction, recorded by the lineation, is not parallel to the flow direction of the magma i.e. displacement. The Black Mesa pluton is a sheeted laccolith on its western edge and a bysmalith on its eastern edge. This E–W asymmetry in pluton geometry/construction and the symmetrical internal fabric indicates that the apparently different west and east growth histories could have occurred simultaneously. Our field data indicate pluton growth through an asymmetric vertical stacking of sill-like horizontal magma sheets.One-dimensional thermal models of the pluton provide maximum limits on the duration of its growth. We have constrained the number, the thickness, and the frequency of magma pulses with our structural observations, including: (1) the emplacement of the pluton by under-accretion of successive magma pulses, (2) the absence of solid-state deformation textures at internal contacts, and (3) the apparent absence of significant recrystallization in the wallrocks. Our results suggest that the emplacement of the Black Mesa pluton was an extremely rapid event, with a maximum duration on the order of 100 years, which requires a minimum vertical displacement rate of the wallrocks immediately above the pluton greater than 2 m/yr. Finally, our data show that the rates of plutonic and volcanic processes could be similar, a significant result for interpretation of magma transfer in arc systems.     

Production of Drinking Water from Highly Contaminated Surface Waters: Removal of Organic,Inorganic, and Microbial Contaminants Applying Mobile Membrane Filtration Units

In military out of area missions of the Bundeswehr, it can be necessary to produce drinking water even from highly polluted surface waters containing a variety of organic, inorganic, and microbiological contaminants. Thus, mobile drinking water purification systems must be able to remove such contaminants as far as possible to meet the requirements of the German and European drinking water regulation/directive. Presently, two novel drinking water purification units applying membrane filtration undergo intensive long‐term trials carried out by the Bundeswehr. If these trials positively proof the functionality of these units and their ability to remove all possible contaminants they shall substitute so far available devices which use large amounts of chemicals and charcoal filtration for water purification.In the course of a research project, the functionality of the new devices and their efficacy to remove high amounts of algae, microbes, and organic and inorganic pollutants are additionally tested in “worst‐case” field studies. In September 2000, the first mobile drinking water purification unit was tested at the Teltowkanal in Berlin, Germany.This canal was chosen because it carries high burdens of municipal sewage effluents. The results from the fatigue test confirmed the ability of the water purification unit to reduce the concentrations of all contaminants meeting the maximum tolerance levels set by the German/European drinking water regulation.The pre‐filtration device was very effective in removing algae and solid particles to protect the membranes from clogging and to enable an almost maintenance‐free operation. Residues of pharmaceuticals and some other organic contaminants have almost totally been removed from the surface water where they were detected at individual concentrations up to the μg/L‐level.     

中国沿岸相对海面变化的本征分析和预测

利用经验正交函数的方法，将平均海面分解为正交时，空函数积的代数和。采用起主导作用的正交函数进行组合，得到修正的海平面变化值，它消除了某些随机的影响。去掉平均海面主要时间本征函数中的主要周期部分，求得剩余部分的变化率，乘以空间本征函数可得各站平均海面的变化速率，对未来的时间本征函数作出预报，便可得到未来的平均海面预报值。     

Determination of particulate organic carbon (POC) in seawater: The relative methodological importance of artificial gains and losses in two glass-fiber-filter-based techniques

Particulate matter in aquatic systems is an important vehicle for the transport of particulate organic carbon (POC). Its accurate measurement is of central importance for the understanding of marine carbon cycling. Previous work has shown that GF/F-filter-based bottle-sample-derived concentration estimates of POC are generally close to or higher than large-volume in-situ-pump-derived values (and in some rare cases in subzero waters are up to two orders of magnitude higher). To further investigate this phenomenon, water samples from the surface and mid-water Northeast Atlantic and the Baltic Sea were analyzed. Our data support a bias of POC concentration estimates caused by adsorption of nitrogen-rich dissolved organic material onto GF/F filters. For surface-ocean samples the mass per unit area of exposed filter and composition of adsorbed material depended on the filtered volume. Amounts of adsorbed OC were enhanced in the surface ocean (typically 0.5 μmol cm^− 2 of exposed filter) as compared to the deep ocean (typically 0.2 μmol cm^− 2 of exposed filter). These dependencies should be taken into account for future POC methodologies. Bottle/pump differences of samples that were not corrected for adsorption were higher in the deep ocean than in the surface ocean. This discrepancy increased in summer. It is shown that POC concentration estimates that were not corrected for adsorption depend not only on the filtered volume, true POC concentration and mass of adsorbed OC, but also on the filter area. However, in all cases we studied, correction for adsorption was important, but not sufficient, to explain bottle/pump differences. Artificial formation of filterable particles and/or processes leading to filterable material being lost from and/or missed by sample-processing procedures must be considered. It can be deduced that the maximum amounts of POC and particulate organic nitrogen (PON) that can be artificially formed per liter of filtered ocean water are  3–4 μM OC (5–10% of dissolved OC) and  0.2–0.5 μM ON (2–10% of dissolved ON), respectively. The relative sensitivities of bottle and pump procedures, and of surface- and deep-ocean material, to artificial particle formation and the missing/losing of material are evaluated. As present procedures do not exist to correct for all possible biasing effects due to artificial particle formation and/or miss/loss of filterable material, uncertainties of filtration-based estimates of POC concentrations need further testing. The challenge now is to further constrain the magnitude of the biasing effects that add to the adsorption effect to reduce the uncertainties of estimates of POC concentrations, inventories and fluxes in the ocean.     

Importance of reversible attachment in predicting E. coli transport in saturated aquifers from column experiments

Drinking water wells indiscriminatingly placed adjacent to fecal contaminated surface water represents a significant but difficult to quantify health risk. Here we seek to understand mechanisms that limit the contamination extent by scaling up bacterial transport results from the laboratory to the field in a well constrained setting. Three pulses of Escherichia coli originating during the early monsoon from a freshly excavated pond receiving latrine effluent in Bangladesh were monitored in 6 wells and modeled with a two-dimensional (2-D) flow and transport model conditioned with measured hydraulic heads. The modeling was performed assuming three different modes of interaction of E. coli with aquifer sands: (1) irreversible attachment only (best-fit k_i = 7.6 day⁻¹); (2) reversible attachment only (k_a = 10.5 and k_d = 0.2 day⁻¹); and (3) a combination of reversible and irreversible modes of attachment (k_a = 60, k_d = 7.6, k_i = 5.2 day⁻¹). Only the third approach adequately reproduced the observed temporal and spatial distribution of E. coli, including a 4-log₁₀ lateral removal distance of ∼9 m. In saturated column experiments, carried out using aquifer sand from the field site, a combination of reversible and irreversible attachment was also required to reproduce the observed breakthrough curves and E. coli retention profiles within the laboratory columns. Applying the laboratory-measured kinetic parameters to the 2-D calibrated flow model of the field site underestimates the observed 4-log₁₀ lateral removal distance by less than a factor of two. This is promising for predicting field scale transport from laboratory experiments.     

Tikhonov's regularization for deconvolution in the empirical Green function method and vertical directivity effect

Application of Tikhonov's technique, using input errors for the parameter of regularization estimation, enhances the accuracy and stability of the reconstruction of a source time function (STF) by the empirical Green function (EGF) method that gives us an opportunity to use simultaneously for analysis body and surface waves data, and to estimate the horizontal and vertical directivity effects. Knowledge of the last is particularly useful for the choice of an active nodal plane of earthquakes with the dip slip fault orientation that allows us to classify these earthquakes to the interplate or intraplate types and thereby to reach the better understanding of tectonic processes in the region of interest.By way of illustration, an attempt to estimate average parameters of faulting in a first approximation is made herein for two Russian Far East large events with opposite types of focal mechanism orientation, strike slip and dip slip. The former is not a matter of interest in the context of vertical directivity effect but enables us to test the method.The directivity analysis of pulse durations and inverse amplitudes of the relative source time functions (RSTFs) restored at eight globally distributed stations IRIS indicates that the destruction in the source of the Neftegorsk earthquake (05/27/1995 M_W=7.1) propagated roughly horizontally in the direction 8±11° during 19.2±0.4 s along the rupture extending 35.5±4.9 km. The calculated slip distribution along the rupture coincides within the error with the results of field geological measurements on the causal surface fault that proves that the Neftegorsk earthquake source is well described by the model of the linear unilateral fault and gives a good assessment of the method applied.The average parameters of faulting in the Kamchatka earthquake (03/08/1999 M_W=6.9) have been determined from data of 13 station IRIS. It was shown that the destruction in its source propagated downward at an angle of about 60° with horizon, in the direction about S156° E, during 13.4±0.2 s, along the rupture totaling 25.5±2.3 km in length. Therefore, the nodal plane, steeply dipped to the SE, was active and this event can be regarded as an intraplate type. Two asperities can be selected; the first with the maximum slip 3.3 m located at a distance of about 7 km from the onset of rupture, and the second with the maximum slip about 0.9 m centered at approximately 19 km from that.