MOVABLE BED EXPERIMENT ON REDUCTION OF SAND DEPOSITION AT OPENING OF NUMAKAWA-DAINI FLOODWAY

Author(s):  
Takaaki UDA ◽  
Tatsuyuki IGARASHI ◽  
Tomoya INAMI ◽  
Tetsuo SAKURADA
Keyword(s):  
Author(s):  
Maria Y. Savostyanova ◽  
◽  
Lidia А. Norina ◽  
Arina V. Nikolaeva ◽  
◽  
...  

Retaining of water resources quality is one of the global ecological problems of the modern time. The most promising direction in solving the problem of water resources protection is the reduction of negative environmental influence of waste water from production facilities by upgrading the existing water treatment technologies. To treat utility water, technical and rain water from site facilities of Transneft system entities, the specialists developed and approved standard technological diagrams, which are used in producing treatment facilities. The standard technological diagrams provide for all necessary stages of waste water treatment ensures the reduction of pollution level to normal values. However, during operation of treatment facilities it was established, that to ensure the required quality of waste water treatment with initially high levels of pollution, the new technological solutions are necessary. The author presents the results of scientific-research work, in the context of which the best affordable technologies were identified in the area of the treatment of waste water with increased content of pollutants and non-uniform ingress pattern. On the basis of the research results the technical solutions were developed for optimization of operation of existing waste water treatment facilities by means of using combined treatment of technical and rain waters and utility waste waters and applying bioreactor with movable bed – biochips. The use of bioreactor with movable bed allows the increase in the area of active surface, which facilitates increase and retention of biomass. Biochips are completely immersed into waste waters, and biofilm is formed on the entire volume of immersion area, facilitating retention of biomass and preventing formation of sediments. Due to mixing the floating device with biofilm constantly moves along the whole area of bioreactor, and, in doing so, speeds up biochemical processes and uniformity of treatment. The advantages of a bioreactor with movable bed – its active sludge durability against increased and changing pollutant concentrations, change of waste water temperature and simplicity of application – ensured the possibility of its use for blending utility waters, technical and rain waters.


2018 ◽  
Author(s):  
Brian E. Bodenbender ◽  
◽  
Edward C. Hansen ◽  
Brian P. Yurk ◽  
Suzanne J. DeVries-Zimmerman ◽  
...  
Keyword(s):  

Author(s):  
Subhash C. Jain ◽  
John F. Kennedy
Keyword(s):  

1991 ◽  
Vol 69 (7) ◽  
pp. 1593-1599 ◽  
Author(s):  
César S. B. Costa ◽  
Ulrich Seeliger ◽  
César V. Cordazzo

We studied the effect of nutrient status and sand movement on the population biology of Panicum racemosum Spreng. over a 5-year period (1982–1986) on mobile, semifixed and fixed coastal foredune habitats in southern Brazil. The soils were deficient in nitrate, phosphate, and potassium (<0.5, 0.2–1.2, and 3–5 mg/kg, respectively) in all habitats, and a gradient of decreasing availability existed from the mobile to the fixed dunes. Half-lives of leaves were shorter in the fixed dune as compared with the mobile dune. Similarly, half-lives of leaves were shorter in summer than in winter. Experiments using cuttings of P. racemosum tillers showed that as P. racemosum plants grew, so did the deposition of sand on mobile foredunes. The mechanical deposition of sand itself did not stimulate P. racemosum growth. The deposition of saline sand provided a substrate that supported vertical growth of P. racemosum rhizomes and tillers and was a source of adsorbed nutrients. Also, active sand deposition limited the invasion of frontal dunes by other species. Panicum racemosum populations changed from "invader" to "mature" to "regressive" age states over a 5-year period, apparently in response to the spatial patterns of sand deposition and salt spray input. Key words: Panicum, leaf demography, growth vigour, sand dunes, temporal changes.


1966 ◽  
Vol 92 (3) ◽  
pp. 45-68
Author(s):  
Howard E. Christian ◽  
Warren J. Mellema ◽  
Walter M. Linder
Keyword(s):  

2000 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Ruel A. Overfelt

Abstract The results of experimental study of pressure variations inside core box during resin bonded sand filling process are reported. The test core specimens were produced using Laempe® Test Specimen Curing Machine L 1. A special pressure measurement system was designed and built with safety and portability requirements of the foundry environment. Special experiments were conducted to establish the effect of sand deposition on vent permeability.


Author(s):  
Steven A. Hughes ◽  
Jimmy E. Fowler
Keyword(s):  

The Holocene ◽  
2016 ◽  
Vol 27 (4) ◽  
pp. 579-593 ◽  
Author(s):  
Stephen A Wolfe ◽  
Olav B Lian ◽  
Christopher H Hugenholtz ◽  
Justine R Riches

The Bigstick and Seward Sand Hills are possibly two of the oldest dune fields within the late Wisconsin glaciated regions of the Northern Great Plains. As with most Northern Great Plains dune fields, source sediments are former proglacial outwash sands. Thus, Holocene dune construction is primarily related to spatial–temporal variations in surface cover and transport capacity, rather than renewed sediment input. However, eolian landscape reconstructions on the Northern Great Plains have been temporally constrained to recent periods of activity, as older episodes of deposition are typically reworked by younger events. In this study, sediment cores from shallow lacustrine basins and interdune areas provide an improved record of Holocene eolian sand deposition. Eolian sand accumulation in the interdunes and basins occurred between 150 and 270 years ago, 1.9 and 3.0 ka, 5.4 and 8.6 ka, and prior to ca. 10.8 ka. These episodes of sand accumulation were bracketed by lacustrine deposition and soil formation, which represented wetter conditions. Other than mid-Holocene dune activity, which may be related to peak warmth and aridity, most periods of eolian sand accumulation coincided with cooler but drier climatic events such as the Younger Dryas, late-Holocene cooling prior to the Medieval Climatic Anomaly, and the ‘Little Ice Age’. These depositional episodes are also spatially represented by other dune fields in the region, providing a broad-scale view of the connections between past climatic events and eolian landscape evolution on the Northern Great Plains.


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