This study is intended to use statistical methods for analyses of how a final waste disposal influences its surrounding environment. The influence is investigated from the viewpoint of birds around the final waste disposal site and vicinity. We observed the ecology of birds using a strip transect sampling. The bird data were classified according to cluster analysis and analyzed using principal component analysis. We newly defined a measure of plant community similar to the vegetation authenticity based on principal component space. We also compared the time series with variations of the observation area.

View full abstract

   Wastewater-contaminated soil is noticed in many residential and industrial districts in various countries in the world. Domestic and industrial wastewater contains many injurious chemical compositions. Many underground septic tanks have been used to collect domestic wastewater from dwelling buildings in Tahta city, Egypt. Soil samples were taken at the depth of foundation level of the buildings and a series of mineralogical and chemical analysis was carried out for contaminated soil samples. Also, physical engineering properties of soil were identified and analyzed at different periods of wastewater exposure time and at variant distances from the contamination source (septic tank). Results showed significant adverse effects of the contaminated soil on mineralogical, chemical and physical properties.

View full abstract

   This work aims to investigate the removal of arsenic from the simulated groundwater by batch adsorption using Iron (ZVI) and Iron[III] Oxide (IO). The effect of initial arsenic concentration, adsorbent dose and pH were investigated. Adsorption equilibrium and its kinetics were also studied. The results showed that both ZVI and IO have a high efficiency for adsorption of arsenic from groundwater. Langmuir isotherm described well the adsorption equilibrium and the pseudo-second order kinetic model gave the best fit with the experimental kinetic data for both ZVI and IO.

View full abstract

   Batch studies on anaerobic digestion were performed in 100ml bench top digesters (serum bottles) with solid wastes (limed fleshing) generated from tannery and primary sludge from effluent treatment plant of tannery liquid waste. Digestion was carried out under mesophilic condition. Batch reactors were run at two different organic loading rates. Gas production was higher in test reactor 1 (volatile solids load of 51.9 g/l) than test reactor 2 (volatile solids load of 15.8 g/l). VFA concentration in test reactors 1 and 2 had reduced by 11,970 mg/l (43%) and 2115 mg/l (28.4%) respectively. As biodegradability fraction present in the tannery solid wastes was lower, lag time for the onset of maximum gas production was longer. Based on experimental observation it is concluded that it is more appropriate to evaluate biomethanation potential of solid wastes in terms of biodegradable fraction of volatile solids present in the wastes.

View full abstract

   The Seto Inland Sea is an appropriate place for offshore wind power generation due to its features of vast shallow waters, numerous islands, calm ocean waves, steady breeze circulation and so on. In this study, offshore wind energy potential in the Seto Inland Sea is estimated based on the wind prediction data of LAWEPS, and the sea areas appropriate for offshore wind power generation are extracted by means of GIS analysis considering the constrained conditions such as wind speed, water depth, natural parks and ship lanes. The results of the estimation show that the maximum annual power generation is 247 TWh and the minimum is 32 TWh. In particular, the Suo-Nada area near the Kanmon Channel seems to be highly promising as the offshore wind power generation site.

View full abstract

  The long-term evolution of deep geological repositories for nuclear waste is governed by geochemical processes in conjunction with mass and energy transport. A key role for the design of the multi-barrier system is the knowledge of long term changes at the interfaces between different materials. We investigate the porosity evolution at a generic interface between clay and cement containing materials. We use novel reactive transport codes that couple a Gibbs Energy Minimization (GEM) chemical equilibrium thermodynamic solver with mass transport solvers. Our simulations show that in the cementitious material, the porosity is increased due to the dissolution of portlandite. At the interface, the porosity is strongly reduced in the clay and cement compartment due to calcite precipitation and due to the precipitation of C-S-H solid solution. The time for clogging the interface is highly variable and depends on transport conditions and on the geochemical setup.

View full abstract

   This paper focuses on the computational efficiency of parallelized finite element method (FEM) for coupled thermo-hydro-mechanical (THM) problems. The numerical analysis of THM coupled problems in porous media is an important subject for many geo-engineering tasks such as engineering of geothermal reservoirs, nuclear waste management and CO2 sequestration. However its calculation is computationally very expensive. Improvement of the computation time is required to expand applicability of the method. Parallel computing is one of the ways to provide it speed-up. In this study, parallelization efficiency on solving the coupled THM problems is presented with several simple tests as well as an application to a three dimensional geothermal reservoir modeling. Tests were conducted using a parallelized FEM code, GeoSys/Rockflow, and a Linux cluster system, LiClus at UFZ. Results show that the parallel computation scheme effectively reduces the calculation time for solving coupled THM problems. It was also found that its parallelization could affect solver behavior. Reducing communication time between cluster nodes is desired to use parallel computing more efficiently.

View full abstract