Flocculation mechanism of the acquisition of remanent magnetization by sedimentary rocks

Coagulation of particles into aggregates during their deposition in a reservoir is numerically simulated with regard for Brownian motion, Van der Waals forces, gravitation, Stokes friction, and magnetostatic interaction, and the effect of this process on the depositional magnetization (DRM) is estimated. Clusters obtained due to random aggregation of smaller clusters have a loose and branching structure. The average fractal dimension of the clusters is d = 1.83 ± 0.23. In the process of coagulation, magnetic particles do not form chains or clusters, as was supposed in a number of preceding works, but become rather uniformly distributed among nonmagnetic particles, which provides an additional argument in favor of the fact that chains of magnetite particles in marine sediments are of biogenic origin rather than a result of mutual attraction of magnetic particles due to magnetostatic interaction. The deposition process is shown to obey a kind of the principle of scale invariance: the number of clusters and their average number of particles do not change if the basin depth H and the surface concentration of initial material c ₀ simultaneously change (provided that temperature and the initial particle size r are constant) in such a way that Hc ₀ = const. Coagulation is the most important factor forming the bottom layer structure and the magnetization of the suspension at a relatively high concentration c ₀ Typical of redeposition conditions, lakes, and shelf seas. Coagulation virtually does not influence oceanic sediments because of the smallness of c ₀.     

Elimination of ghost noise in vibroseis data by deconvolution

A deconvolution approach is presented to process uncorrelated vibroseis data. The recorded ground force signal, known to be a better correlator for the vibrogram than the pilot sweep itself, is used to deconvolve rather than to correlate the vibrogram. In such a way the ghost sweep (correlation noise), produced by severe harmonic distortions in the ground force signal both at negative and positive correlation times if such a signal is used as the correlator, is eliminated automatically. This type of deconvolution can eliminate the ghost sweep caused by both the upsweep or by the downsweep signal. Synthetic and real data are used to demonstrate the application of the deconvolution procedure. The results are compared with the traditional correlation procedure and show the superiority of the deconvolution approach.     

Flocculation and the loss of sediment from the Po River plume

In October 2000, a 100-year flood event in the Po River resulted in the formation of a fine-grained sediment deposit extending up to 10 km from the river mouth. Soon after this event, and for a subsequent period of 2 years, box cores were collected on a grid of stations off of the Po Delta to observe the evolution of the flood deposit. Using a process-based parameterization of the disaggregated inorganic grain size distribution, the evolution of the surficial sediment on the Po shelf since the 2000 flood has been interpreted in the context of particle flocculation dynamics. This method produces estimates of floc limit, the diameter at which the flux of single grains to the seabed equals the flux of flocs, and floc mass fraction, the amount of material deposited as flocs. Floc limit depends on the extent of flocculation in suspension, and floc mass fraction describes the extent of flocculation in the sediment. Immediately after the flood, these two parameters were high at stations located beneath the path of the flood plume as observed in satellite images. The occurrence of a highly flocculated deposit below the path of the plume leads to two hypotheses: (1) the high sediment concentration in the river flood plume produced extensive sediment flocculation in the plume and (2) post-depositional remobilization of sediment delivered from the plume to the seabed was limited in the relatively low-energy environment of the Po prodelta. Floc limit and floc mass fraction estimated from bottom sediment sampling 3 and 10 months after the initial sampling were lower, indicating that during normal discharge, flocculated fine-grained sediment from the Po River settles close to the mouth, leaving only a small amount of material in suspension in the plume for direct deposition onto the prodelta. These findings are consistent with laboratory studies of suspended sediment that show that sediment concentration and turbulent energy exert dominant control on the extent of flocculation and the loss of sediment from suspension.     

Turbidity Removal from Wastewaters of Natural Stone Processing by Coagulation/Flocculation Methods

The effectiveness of coagulation (at pH values of 6, 7.5, and 9), flocculation (at pH 9), and coagulation plus flocculation (at pH 9) on turbidity removal from natural stone (travertine) processing wastewaters (NSPW) were examined by applying classical sedimentation tests. FeCl₃·6 H₂O, AlCl₃, and Al₂(SO₄)₃·16 H₂O were used as coagulants and a polyacrylamide based anionic polymer was used as the flocculant. In this way, it was found that the coagulation method alone was not sufficient to purify NSPW, whereas flocculation and coagulation plus flocculation methods provided superior purification. Among the coagulants used, AlCl₃ gave the best result in terms of turbidity removal by coagulation from NSPW at pH 6 and 9, whereas the turbidity removal performances of the three coagulants were almost identical at pH 7.5. In addition, relatively low pH (i. e., pH 6) improved the purification performance of all coagulants. During coagulation of NSPW at pH 6, a charge neutralization mechanism played a decisive role in turbidity removal. However, in neutral (pH 7.5) and slightly basic (pH 9) media, a sweep coagulation mechanism was predominant. For flocculation of NSPW, the basic mechanism comprised of polymer bridging.     

地电供电对地磁观测干扰的排除

随着数字化地震技术的发展,台站逐步进入了智能化的管理,各台站都相应地使用了计算机和数字化智能仪器,目前许多地震台站的地磁观测都安装了ＺＮＣ－Ⅱ质子智能磁力仪,每分钟观测一个地磁Ｚ分量值,并利用设定的程序将它记录在单片机上,通过信号线与计算机相接,能够...     

Elimination of Noise Caused by Spikes and Bursts in Vibroseis Data

—Seismic recording systems without a telemetry system have often been affected by electromagnetic induced spikes or bursts, which lead to strong data distortions combined with the correlation process of the vibroseis method. Partial or total loss of the desired seismic information is possible if no automatic spike and burst reduction is available in the field prior to vertical stacking and correlation of the field record.¶Currently, combined with the use of modern telemetry recording systems, the most common noise reduction methods in vibroseis techniques (e.g., spike and burst reduction, diversity stack) are already applied in the field to reduce noise in a very early state. The success of these automatic correction methods depends on the fundamental principles of the recording situation, the actual characteristic of the distorting noise and the parameter justification by the operator. Since field data are usually correlated and already vertical stacked in the field to minimize logistical and processing costs, no subsequent parameter corrections are possible to optimize the noise reduction after correlation and vertical stacking of a production record.¶The noise reduction method described in this paper uses final recorded and stacked vibroseis field data at the correlated or uncorrelated stage of processing. The method eliminates signal artifacts caused by spikes or bursts combined with a standard convolution process. A modified correlation operator compresses the noise artifact in time using a single trace convolution process. After elimination of this compressed noise, re-application of the convolution process leads to a noise-corrected replacement of the input data. The efficiency of the method is shown with a synthetic data set and a real vibroseis field record. Furthermore, several thousand records from a 2-D deep seismic reflection project could be corrected with good results using this method.     

Elimination of the non-linearity of the sharpe gravimeter scale

Summary A new method for calibrating the Sharpe gravimeter was derived in order to eliminate the non-linearity of the scale.     

Elimination of high-amplitude noise during passive monitoring of hydrocarbon deposits by the emission tomography method

Emission tomography used in passive seismic monitoring of hydrocarbon deposits enables regular inspection of development of hydraulic fracturing and relaxation processes in volumes of fracturing, tracing of fluid migration paths, redistribution of stresses due to field development accompanied by seismic emission from volumes of structural defects and stress concentration, and localization of fractured and faulted structures from emission and scattering data. Intensive man-made seismic noise in the areas of oil field development produces a strong screening effect in identification of weak deep seismic sources. On the basis of experiments with simulated and real data of surface seismic arrays in regions of oil deposits in Western Siberia (carried out in the framework of the passive monitoring program of the SYNAPSE Science Center), it is shown that the use of algorithms of adaptive optimal and rejection spatial filtering with the estimation of the spectral density matrix of multichannel observations in the framework of multivariate autoregressive-moving average modeling is effective for eliminating the influence of anthropogenic noise and revealing (in oil production areas) both deep seismic sources supposedly active in scattering regions of the lower part of the sedimentary cover and the crystalline basement. The projection of the scattering regions onto the horizontal plane correlates well with the position of faults in the area of in situ observations.     

Elimination of Carbamazepine,Diclofenac and Naproxen from Treated Wastewater by Nanofiltration

Most conventional wastewater treatment plants remove very small amounts of micropollutants, such as pharmaceuticals. Here, the ability of two different types of submerged nanofiltration flat sheet modules to remove pharmaceuticals from wastewater is analyzed. The two nanofiltration membranes were used at relatively low pressures of only 0.3 and 0.7 bar. At such low pressures, the membranes did not retain salts to a great extent. This is advantageous in wastewater treatment because no salt concentrate is produced. Carbamazepine was retained only slightly by the nanofiltration membranes, whereas approximately 60% of diclofenac and naproxen were retained by both membranes. This level of effectiveness might not be enough to justify the use of such a system as an additional treatment step in wastewater treatment plants.     

A Contribution to the Mechanism of Elimination of Dimethylformamide and Dimethylamine by a Heterogenous Culture of Microorganisms

In a batch experiment with activated sludge from a large-scale plant the hydrolytical and biochemical degradation of dimethylformamide (DMF) and its reaction product dimethylamine (DMA) and the conversion connected with this under aerobic and anaerobic conditions is investigated. Parallel to the hydrolysis of DMF the biochemical degradation of DMA occurs. The extensive conversion of these substrates is followed by the nitrification of the ammoniumions formed, and under subsequent anaerobic conditions with methanol as the carbon source also denitrification can be achieved. If the oxygen supply of the activated sludge is insufficient, however, also DMA can be used as a carbon source for denitrification, ammonium-ions being released from DMA in addition. In the batch experiment the elimination rates referred to nitrogen were 7 … 14 mg/g · h for DMF, 0.8 … 1.7 mg/g · h for DMA, 0.3 … 0.6 mg/g · h for NH and 0.4 to 1.3 mg/g · h for nitrate in the presence of methanol. DMF and DMA are obviously not suitable as the only carbon source for denitrification.     

Elimination of Nutrients in the Rozkoš-Reservoir

The reservoir, having a volume of 76 hm³, a surface area of 1001 ha and a maximum depth of 17 m, is divided by a dam into two parts. Half of the upper part with an area of 200 ha is densely covered by macrophytes (Elodea, Potamogeton). The three main tributaries with 2.6 m³/s on an average are highly polluted and show α-mesosaprobic conditions. The reservoir is investigated between September and March in its longitudinal section at eight stations. The organic load and the total solids show a total decrease by 60% and 66%, respectively, and 70% of this selfpurification occurs in the upper, separated part of the reservoir. In the same way, also the total nitrogen is reduced, whereas the total phosphorus is reduced already in the upper part of the reservoir by 71%, then decreasing to 21% in the second part of the reservoir. With phosphorus, besides the biological elimination obviously also precipitation by the dissolved iron occurs, the concentration of which is reduced by 44 or 76%, resp. The bacteriological load of water improved by two to three orders of magnitude.     

Elimination of fine suspensoids in the oceanic water column

Fine suspended materials in the particle-size range1 < r < 6 μm (r, equivalent sphere radius) from the equatorial North Atlantic, between the ocean surface and greater depths (30–5100 m), can be consistently described by a size-distribution relationshipdN/dr = Ar^?b, where the parametersA andb are independent ofr. The shape of the particle-size distribution is essentially constant and independent of depth, as reflected in the values of the logarithmic slope of the size distributionb = 4.0 ± 0.3. The particle-number and mass concentration, however, decrease strongly with depth, most of the decrease taking place in the surface layer 200 m deep. In the surface layer, mass concentration decreases exponentially with the half-concentration depthz_1/2 ? 60m; in the deep layer (200–5000 m),z_1/2 ? 1000m. The computed removal half-lives of the particulate material are0.8 ± 0.6yr in the surface layer, and60 ± 20yr in the deep layer, both half-lives being considerably shorter than Stokes settling residence times. The fast turnover or removal rate in the surface layer is compatible with the rates of zooplankton growth and carbon assimilation.     

Flocculation and particle size analysis of expansive clay sediments affected by biological, chemical, and hydrodynamic factors

Expansive clay sediments are abundant in riverine and estuarine waters and bottom beds, and their particle size distributions (PSD) are important for the analysis of sediment transport. This paper presents an experimental study to evaluate, using a laser particle size analyzer under varying flow conditions, the intrinsic PSD of two expansive clays, a Ca- and a Na-montmorillonite and the influence of biological, chemical, and hydrodynamic factors on their flocculation and PSD. The considered biological factor consists of three extracellular polymeric substances of varying polarity, including xanthan gum, guar gum, and chitosan; the chemical factor is the salinity; and the hydrodynamic factor is the types of flow indicated by the Reynolds number and shear rate. The intrinsic PSD of both clays show a multimodal lognormal distribution with sizes ranging from 0.2 to 50 μm. All three biopolymers, xanthan gum, guar gum, and chitosan, can facilitate flocculation through long-range polymer bridging and short-range ion-dipole interaction, hydrogen bonding, and Coulomb force. The influence of salinity is different for the two clays: the particle size of the Na-montmorillonite increases with salinity, which is caused by flocculation resulting from the suppressed electrical double layer, while that of the Ca-montmorillonite is slightly reduced owing to the decreased basal spacing and cation exchange. For different hydrodynamic conditions, higher shear rate promotes the flocculation of Ca-montmorillonite, but breaks the Na-montmorillonite flocs. The significance of understanding the flocculation and PSD of expansive clays is also discussed in terms of sediment transport under different aquatic environments.     

Some Methods of Phenol Elimination from Sewage Waters. Part 1: Biodestruction by the Vegetable Homogenates

The different phenoloxidase contents of shoots of various land plants (sunflower, corn, wheat, potato) as well as of various algal species were used for investigating the biochemical conversion and accumulation of phenol, p-and o-cresol, guaiacol, pyrocatechol and hydroquinone. The methods applied for processes and analyses are described. The results of the investigations are summarized in several tables and graphical representations.     

Treatment of Sewage Containing Aromatic Amines with Participation of Macrophytes. Part 1. Mechanisms and Kinetics of the Elimination of Aromatic Amines by Macrophytes

Results are presented of studying quantitative regularities of utilizing aromatic amines (benzidine, α- naphthylamine) by Chara algae (Nitella spec., Charafragilis) and higher aquatic plants (Elodea canadensis). It is shown that the basic part of eliminated benzidine is subjected to oxidative conversions under the action of macrophyte enzyme systems. Not more than 20% of eliminated benzidine accumulate in vegetative tissues.     

Interactions of Chlorine with Natural Organic Matter and Formation of Intermediates: Evidence by Differential Spectroscopy

This communication describes the use of differential absorbance spectroscopy to explore the intermediates formed during halogenation of natural organic matter (NOM). The differential spectra of chlorinated NOM comprise two contributions. The primary component is negative and has a peak near 270 nm. The shape of this band is independent of chlorine dose, and its intensity increases monotonically with Cl₂ dose. The second component is positive, with a well‐defined peak near 280 nm and another, broader band in the 340...380 nm range. The second component is noticeable at low chlorine concentrations but disappears with increasing Cl₂ dose. We attribute this component to aromatic chlorinated intermediates formed prior to the release of identifiable smaller species such as haloacetic acids. We believe that this component of the differential spectra can be used to probe the identity, formation and breakdown of the halogenated intermediates.     

Optimization of the Coagulation–Flocculation Process for Slaughterhouse Wastewater Using Response Surface Methodology

Slaughterhouse wastewater is one of the main sources of environmental pollutants, containing a high amount of organic matter (chemical oxygen demand (COD), biochemical oxygen demand (BOD)), total nitrogen (TN), total suspended solids (TSS), total phosphorus (TP), grease, and oil. The main aim of the present research is optimizing the coagulation–flocculation process and examining the effects of experimental factors with each other, for example, pH, the concentration of two different coagulants (FeCl₃ and alum), rapid mixing rate, and settling time. Therefore, it is aimed to treat slaughterhouse wastewater using the coagulation–flocculation process with the optimization of the response surface methodology (RSM). COD, turbidity, and suspended solids (SS) of the treated wastewater are chosen as the response variables. Furthermore, the optimal conditions for three responses are acquired by employing the desirability function approach. When the experimental results of two coagulants are compared, it is observed that the alum coagulant gave better results for the three responses. The alum coagulant utilized in the present research is able to increase COD, SS, and turbidity removal efficiency by 75.25%, 90.16%, and 91.18%, respectively. It is possible to optimize coagulation–flocculation by utilizing the RSM analysis, which proves that coagulation can pre‐treat slaughterhouse wastewater.