Case histories illustrate the importance of secondary-type consolidation settlements in the Fraser River delta

1996 ◽  
Vol 33 (6) ◽  
pp. 866-878 ◽  
Author(s):  
Carl B Crawford ◽  
K Ian Morrison

The technique of preloading the deep, compressible soils in the Fraser River delta has been used for more than 40 years to prevent excessive settlement of major structures. This paper documents 22 years of settlement under preloading and after construction of the facilities for a major waste water treatment plant in the delta. These results are similar to observations for as long as 28 years at five additional sites in the delta. It was found that as much as one half of the measured surface settlement occured during or within a few weeks of the full apllication of the preload and that subsequent settlements have the characteristics of secondary consolidation. This could not have been predicted from laboratory tests, and it raises questions concerning the true nature of consolidation in situ. For practical purposes the observations provide guidance for the prediction of long-term settlements in the region. Key words: case history, consolidation, field observations, preloading, settlement.

RADIOISOTOPES ◽  
1979 ◽  
Vol 28 (6) ◽  
pp. 374-376
Author(s):  
Haruo CHISAKA ◽  
Takashi SUZUKI ◽  
Yasuhiro OKANO ◽  
Yukio INOKOSHI ◽  
Yasuhiro HORIGUCHI ◽  
...  

2010 ◽  
Vol 61 (7) ◽  
pp. 1811-1818 ◽  
Author(s):  
C. Slater ◽  
J. Cleary ◽  
K.-T. Lau ◽  
D. Snakenborg ◽  
B. Corcoran ◽  
...  

This work describes the design of a phosphate analyser that utilises a microfluidic lab-on-a-chip. The analyser contains all the required chemical storage, pumping and electronic components to carry out a complete phosphate assay. The system is self-calibrating and self-cleaning, thus capable of long-term operation. This was proven by a bench top calibration of the analyser using standard solutions and also by comparing the analyser's performance to a commercially available phosphate monitor installed at a waste water treatment plant. The output of the microfluidic lab-on-a-chip analyser was shown to have sensitivity and linear range equivalent to the commercially available monitor and also the ability to operate over an extended period of time.


2016 ◽  
Vol 9 (2) ◽  
Author(s):  
Dinda Rita K. Hartaja ◽  
Imam Setiadi

Generally, wastewater of nata de coco industry contains suspended solids and COD were high, ranging from 90,000 mg / l. The high level of of the wastewater pollutants, resulting in nata de coco industry can not be directly disposed of its wastewater into the environment agency. Appropriate technology required in order to process the waste water so that the treated water can meet the environmental quality standards that are allowed. Designing the waste water treatment plant that is suitable and efficient for treating industrial wastewater nata de coco is the activated sludge process. Wastewater treatment using activated sludge process of conventional (standard) generally consists of initial sedimentation, aeration and final sedimentation.Keywords : Activated Sludge, Design, IPAL


1991 ◽  
Vol 23 (4-6) ◽  
pp. 825-834 ◽  
Author(s):  
T. H. Lessel

The upgrading and nitrification was required for the waste water treatment plant in Geiselbullach. As space for more aeration tanks was not available, the possibility of increasing the MLSS by the use of submerged bio-film reactors was tested in a half technical scale pilot plant with three different reactor materials. Each tested reactor material caused a significant increase of MLSS and the nitrification reaction. The rope-type material was selected for the practical application, as it had not the same disadvantages of the other tested systems, which proved operational problems. After one year of continuous operation for nitrification in the full scale plant the influences on the biomass characteristics were investigated. Design criterias and details and operational data are reported.


1991 ◽  
Vol 24 (10) ◽  
pp. 161-170 ◽  
Author(s):  
M. D. Sinke

Until a century ago, The Hague's waste water was discharged directly into the city's canals. However, the obnoxious smell and resultant pollution of local waters and beaches then necessitated the implementation of a policy of collecting and transferring waste water by means of a system of sewers. By 1937, it was being discharged, via a 400 metre-long sea outfall, directly into the North Sea. By 1967, however, the increasing volume of waste water being generated by The Hague and the surrounding conurbations called for the construction of a primary sedimentation plant. This had two sea outfalls, one 2.5 km long and the other 10 km long, the former for discharging pre-settled waste water and the latter for discharging sludge directly into the North Sea. This “separation plant” was enlarged during the period 1986-1990. On account of the little available area - only 4.1 ha - the plant had to be enlarged in two stages by constructing a biological treatment section and a sludge treatment section with a capacity of 1,700,000 p.e. (at 136 gr O2/p.e./day). In order to gain additional space, a number of special measures were introduced, including aerating gas containing 90% oxygen and stacked final clarifiers. Following completion of the sludge treatment section, it has become possible, since 1st May 1990, to dump digested sludge into a large reservoir (“The Slufter”), specially constructed to accommodate polluted mud dredged from the Rotterdam harbours and waterways. As a result of these measures, there has been a reduction of between 70% and 95% in North Sea pollution arising from the “Houtrust” waste water treatment plant. Related investment totalled Dfl. 200 million and annual operating and maintenance costs (including investment charges) will amount to Dfl. 30 million. Further measures will have to be taken in the future to reduce the discharge of phosphorus and nitrogen. So this enlargement is not the end. There will be continued extension of the purification operations of the “Houtrust” waste water treatment plant.


1992 ◽  
Vol 25 (4-5) ◽  
pp. 225-232
Author(s):  
C. F. Seyfried ◽  
P. Hartwig

This is a report on the design and operating results of two waste water treatment plants which make use of biological nitrogen and phosphate elimination. Both plants are characterized by load situations that are unfavourable for biological P elimination. The influent of the HILDESHEIM WASTE WATER TREATMENT PLANT contains nitrates and little BOD5. Use of the ISAH process ensures the optimum exploitation of the easily degradable substrate for the redissolution of phosphates. Over 70 % phosphate elimination and effluent concentrations of 1.3 mg PO4-P/I have been achieved. Due to severe seasonal fluctuations in loading the activated sludge plant of the HUSUM WASTE WATER TREATMENT PLANT has to be operated in the stabilization range (F/M ≤ 0.05 kg/(kg·d)) in order not to infringe the required effluent values of 3.9 mg NH4-N/l (2-h-average). The production of surplus sludge is at times too small to allow biological phosphate elimination to be effected in the main stream process. The CISAH (Combined ISAH) process is a combination of the fullstream with the side stream process. It is used in order to achieve the optimum exploitation of biological phosphate elimination by the precipitation of a stripped side stream with a high phosphate content when necessary.


1996 ◽  
Vol 33 (12) ◽  
pp. 251-254
Author(s):  
Karl Arno Bäumer ◽  
Angela Baumann

The Institute for Water and Waste Management (ISA) at the Aachen University of Technology (RWTH) verified, through semi-technical analysis, the efficiency of the planned upgrade of the Kleve-Salmorth waste water treatment plant. Additionally the allowable biological phosphorus removal limit and the scheduled simultaneous precipitation were also ascertained.


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