Zusammenhänge Zwischen Radonanomalien und Schwarm-Erdbeben im Oberen Vogtland

Abstract

The results of continuous radon measurements in soil air and the water of a mineral spring at Bad Brambach are presented. They are discussed in connection with meteorological, hydrological parameters, and seismic events with magnitudes <3. The atmospheric pressure (especially pressure gradient), the temperature, and the groundwater level gradient have a significant influence onto radon activity of soil air.

The gamma-activity in spring water is influenced by the water flow rate only.

The results show that the soil air (mean Rn activity 130 Bq · l^?1) and especially the water of the Radonquelle of Bad Brambach (mean Rn activity 25 kBq · l^?1) react upon micro earthquakes with small epicentral distances. Frequently there are precursor effects, that means radon maxima due to the building up of tectonic stress/strain.

About 60% of the seismic events had been attended by radon anomalies during the registration period.

The long term measurements will be continued to investigate possible influences of earthquakes with higher epicentral distances and magnitudes >5 onto the radon regime of the bad Brambach area.     

Comparison of On-Column and Splitless Injections for the Capillary Gc Quantitation of Organics Extracted from Landfill Leachatesl

Abstract

An extensive study of the organic components of the leachate from the University of Connecticut landfill has been carried out. A modification of EPA Method 625 for base/neutral extractable organics was used to obtain both the gas chromatographic profiles and the mass spectrometric identification of the organics in groundwater samples from six test wells and several private wells in the vicinity of the landfill. A characteristic fingerprint representing a number of components was consistently found in the analysis of the landfill leachate but not in the drinking water of the private residences located on an adjoining road. Gas chromatographic parameters for optimum qualitative and quantitative analysis of field samples were determined using an acetone solution of the model leachate sample. It was confirmed that the on-column injection mode resulted in greater flame ionization detector (FID) response and more reproducible peak areas than the splitless mode. The major variable in obtaining reproducible data was the field sampling at the landfill, not the solvent reduction step or the injection mode used to introduce the sample into the gas chromatograph.     

Health risk assessment of heavy metals and their source apportionment in drinking water of Kohistan region, northern Pakistan

The present study was conducted to investigate heavy metal (Cu, Co, Cr, Mn, Ni, Pb, Zn and Cd) concentrations of drinking water (surface water and groundwater) samples in Kohistan region, northern Pakistan. Furthermore, the study aimed to ascertain potential health risk of heavy metal (HM) concentrations to local population. HM concentrations were analyzed by using graphite furnace atomic absorption spectrometer (Perkin Elmer, AAS-PEA-700) and were compared with permissible limits set by Pakistan Environmental Protection Agency (Pak EPA) and World Health Organization (WHO). Based on HM concentrations the health risk assessment like chronic daily intake (CDI) and hazard quotient (HQ) was calculated. The values for CDI were found in the order of Zn > Cu > Mn > Pb > Cr > Ni > Cd > Co and the values of HQ were < 1 for all HM in drinking water samples indicating no health risk. Furthermore, multivariate statistical analysis like one-way ANOVA, inter-metal correlation, cluster analysis (CA) and principal component analysis (PCA) results revealed that geogenic and anthropogenic activities were major sources of water contamination in Kohistan region.     

State-space modeling for seismic signal analysis

The time series utilized for geodetic signal analysis, such as strain and groundwater level data, usually is largely affected by barometric pressure, earth tide and precipitation, and also suffer from missing observations due to instrument maintenance or breakdown. To detect informative geodetic signal from heavily noise-affected data, one must build a time series model for decomposition of the data taking into account the characteristics of effects from these covariates. This paper proposes a new modeling method for detecting geodetic signal from earthquake-related time series data by introducing pole-restricted precipitation model, jump component and pre-processing with AR model for interpolating missing observations. Using the proposed method, a geodetic sample data can be decomposed stably into several components including geodetic trend signal, barometric pressure response, earth tidal response, precipitation response and data level shift due to mechanical maintenance or breakdown. The decomposition of the time series and the interpolation of the missing observations are performed very efficiently by using the state-space representation and the Kalman filter/smoother. Finally, case studies of real geodetic sample data demonstrate the effectiveness of the proposed modeling method that lead to some important findings in seismology.     

FLEXIBLE TECHNOLOGY AND THE COST OF IMPROVING GROUNDWATER QUALITY

Contamination of groundwater by agricultural and industrial chemicals is a significant public health problem in the United States and other nations. In recent years, regulations regarding acceptable groundwater quality, particularly for drinking water, have proliferated in response to heightened public awareness of health risks. To minimize the burden on the economy of providing high-quality water, it is necessary to be creative with regard to cleanup strategies. Making treatment technology flexible can reduce the cost of improving groundwater quality by avoiding unnecessary duplication of fixed costs. We consider two types of flexibility. The first is mobility of treatment technology among locations within a single water delivery system. We calculate the costs of compliance with drinking water quality regulations when treatment technologies are fixed and when they are mobile between locations, and show that mobility has significant economic advantages. The second type of flexibility is mobility among water delivery systems, which we capture through a regional rental market for treatment devices. We show that, under certain conditions, rental markets for treatment technology can lower the costs of improving water quality.     

河北平原地下水动力环境演化影响因素的关联度分析

本文以河北平原典型地区-石家庄、衡水、沧州地区为例,采用灰色关联度分析方法,分析了地下水动力环境演化的影响因素。结果表明,对于第一含水组地下水,水动力环境演化主要受气象因素控制,对于第三含水组及漏斗区地下水,人为开采是最直接的影响因素。     

宝鸡市狄家坡滑坡稳定性研究

宝鸡市狄家坡斜坡是一个古滑坡。在调查滑坡区水文地质和工程地质条件的前提下, 本文描述了滑坡的形态与物质结构、滑坡表层的变形破坏特征及其影响因素, 探讨了古滑坡的发生机制。引用可以任意条分块体的Sarma方法, 研究了该滑坡在自然、地震、饱水和三者同时存在共四种状态下的稳定性, 并进行了斜坡表层黄土坡体的稳定性对于地下水位上升的敏感性分析。基本结论是, 狄家坡滑坡在整体上是稳定的, 其表层的黄土坡体在地下水位上升时会发生失稳破坏。最后, 提出了进行滑坡防治的工程对策。     

地下水对工程和环境的作用

地下水对上程建设和地质环境的作用与影响日趋显著,人们认识日益深化。实践表明,这类问题不完伞是纯水文地质问题。实质上,它是介乎于水文地质与工程地质之间,暂定名为“工程水文地质学”。专门进行在工程建设和环境地质中由于地下水作用而产生的各类工程地质问题或水文地质问题。为充分阐明问题,本文从水与岩土相互作用、基坑排水与潜蚀流沙、地基沉降与黄土湿陷、道路冻害与隧道涌水、矿抗突水与竖井破坏、坝基渗漏与稳定、坝基抗滑稳定以及与地下水有关的地质灾害问题等方面,进行了举例阐述,初步论证了重要性、问题和某些实质。目的在于,向人们揭示一个值得研究的方向,并给予充分的重视。     

Synthesis,characterization and batch assessment of groundwater fluoride removal capacity of trimetal Mg/Ce/Mn oxide-modified diatomaceous earth

In this study, trimetal Mg/Ce/Mn oxide-modified diatomaceous earth (DE) was synthesized at optimal conditions. Comparison of the SEM images and the results of EDX analyses of the raw and the modified DE confirmed the surface modification of the raw DE with the trimetal oxide. Groundwater fluoride removal capacity of the sorbent was evaluated by batch method at various defluoridation conditions. At a sorbent dosage of 0.6 g/100 mL (contact time: 60 min, mixing speed of 200 rpm and temperature: 297 K), the fluoride removal was >93% for solutions containing initial fluoride concentration of 10–60 mg/L. Sorbent’s optimum fluoride uptake capacity was 12.63 mg/g at the initial fluoride concentration of 100 mg/L. Fluoride removal was >91% for solutions with initial pH range of ∼4–11 (initial fluoride concentration: 9 mg/L, sorbent dosage: 0.6 g/100 mL). Appraisal of the effect of co-existing anions on fluoride removal showed that CO₃²⁻ would reduce the amount of fluoride removed from solution, while other anions such as PO₄³⁻, NO₃⁻ and SO₄²⁻ had no observable effect. K₂SO₄ solution was found to be most suitable for regeneration of spent Mg/Ce/Mn oxide-modified DE compared to Na₂CO₃ and NaOH. The mechanism of fluoride removal at pH > 5.45 (pHpzc = 5.45) occurred by exchange of hydroxyl groups on surface of sorbent with fluoride ions from solution. Sorption data fitted better to Langmuir isotherm and pseudo-second-order model. External diffusion was observed to be the sorption rate limiting factor.     

A one-dimensional moving grid solution for the coupled non-linear equations governing multiphase flow in porous media. 1: Model development

A straightforward moving grid finite element method is developed to solve the one-dimensional coupled system of non-linear partial differential equations (PDEs) governing two- and three-phase flow in porous media. The method combines features from a number of self-adaptive grid techniques. These techniques are the equidistribution, the moving grid finite element and the local grid refinement/coarsening methods. Two equidistribution criteria, based on solution gradient and curvature, are employed and nodal distributions are computed iterativcly. Using the developed approach, an intermingle-free nodal distribution is guaranteed. The method involves examination of a single representative gradient to facilitate the application of moving grid algorithms to solve a non-linear coupled set of PDEs and includes a feature to limit mass balance error during nodal redistribution. The finite element part of the developed algorithm is verified against an existing finite difference model. A numerical simulation example involving a single-front two-phase flow problem is presented to illustrate model performance. Additional simulation examples are given in Part 2 of this paper. These examples include single and double moving fronts in two- and three-phase flow systems incorporating source/sink terms. Simulation sensitivity to the moving grid parameters is also explored in Part 2.