CHANGES OF MICROPARTICLES AND BACTERIA IN GAPPEI-SYORI JOHKASOU AND RESIDUAL ORGANIC MATTER IN WATER OF THE TREATED WATER TANK

2018 ◽  
Vol 74 (7) ◽  
pp. III_415-III_422
Author(s):  
Yasushi ISHIGURO ◽  
Guangyu CUI ◽  
Tomonari FUJISAWA ◽  
Katsuhito YASUFUKU ◽  
Shinya OKUMURA ◽  
...  
2020 ◽  
Vol 55 (2) ◽  
pp. 184-197
Author(s):  
Saeideh Mirzaei ◽  
Beata Gorczyca

Abstract In this study, diffused aeration was applied to remove trihalomethane (THM) compounds from chlorinated, treated water containing high dissolved organic carbon (DOC) of 6.8 ± 1.2 mg/L. Increasing air-to-water volumetric ratio (rA/W) from 16 to 39 enhanced total THM (TTHM) removal from 60 to 70% at 20 °C and from 30 to 50% at 4 °C. Although bromodichloromethane has lower Henry's law constant than chloroform (CF), it was removed by a higher degree than CF in some aeration trials. Albeit obtaining high removals in aeration, TTHM reformed, and their concentration surpassed the Canadian guideline of 100 ppb in about 24 hours at 20 °C and 40 hours at 10 °C in all attempted air-to-water ratios. The water age in the system investigated in this study varied from 48 hours in midpoint chlorine boosting stations to 336 hours in the nearest endpoint. This study showed that THM removal by aeration is not a viable solution to control the concentration of these disinfection by-products in high-DOC treated water and in distribution systems where water age exceeds 24 hours; unless, it is going to be installed at the distribution endpoints.


2017 ◽  
Vol 18 (1) ◽  
pp. 40-48 ◽  
Author(s):  
Sylvie Kunz ◽  
Luis G. Romero-Esquivel ◽  
Philipp Otter ◽  
Ulrike Feistel ◽  
Thomas Grischek ◽  
...  

Abstract A novel treatment was tested with groundwater to investigate its arsenic removal under natural conditions. The system utilised in-line electrochlorination to oxidise water constituents without the need for external chemical supply. The oxidised arsenic and iron co-precipitated and were filtered via Greensand Plus™. The filter was catalytically active and provided an emergency oxidant. The system had only a few maintenance requirements due to online water quality monitoring. The contaminant removal during the field test in Costa Rica was impaired by strong fluctuations in water quality including low iron concentrations. However, the system removed on average 68% of the arsenic. Mean values of arsenic were 40 ± 23 μg/L in groundwater and 13 ± 6 μg/L in treated water. Iron was removed from an average of 2.8 ± 2.4 mg/L to 0.2 ± 0.2 mg/L (93% removal). Free chlorine produced and available in the treated water tank had a mean concentration of 1.25 mg/L and 0.64 mg/L, respectively.


2013 ◽  
Vol 448-453 ◽  
pp. 317-321 ◽  
Author(s):  
Jing Wen Cao ◽  
Shao Wei Liao ◽  
Chung Yi Chung ◽  
Hwa Sheng Gau ◽  
Chun Yen Chiu ◽  
...  

In this research, the UV absorbance values of wavelength at 210 and 254 nm, excitation emission fluorescent matrix were measured for source water and treated water in CCL (Cheng Ching Lake) water treatment plant during five months. The whole data produced from EEFM was analyzed by PARAFAC operated in MATLAB software. The variation of molecular weight for organic matter was measured by HPLC (high performance liquid chromatography) with UV and fluorescent detectors. Observed from the variation of UV210/UV254, high value in treated water compared with source water was found. More molecular weight less than 5 k Da was formed in the treated water with relative to source water. Also, both major components in source water were located at wavelengths of excitation/emission of 250/410 nm and 230/330 nm and those in treated water were 240/410 nm and 220/290 nm. Also, the fluorescent intensity, long excitation wavelength was higher than short excitation wavelength in source water. This phenomena was opposite with treated water.


2004 ◽  
Vol 144 (1-3) ◽  
pp. 183-190 ◽  
Author(s):  
Dolores Bellido-Milla ◽  
Anabel O�ate-Ja�n ◽  
Jose M. Palacios-Santander ◽  
Dolores Palacios-Tejero ◽  
Mar�a P. Hern�ndez-Artiga

1938 ◽  
Vol 28 (3) ◽  
pp. 393-400 ◽  
Author(s):  
J. S. Hosking

The low temperature ignition of soil organic matter has been investigated for temperatures ranging from 100 to 500° C.Appreciable losses are found to occur below 100° C.; up to 200° C. heating results essentially in the distillation of volatile constituents, while between this temperature and 300° C. destructive distillation is the major reaction. These reactions are responsible for the removal of 85% of the soil organic matter.By 300° C. the greater part of the residual organic matter consists of carbonaceous material, and the final reaction is simple ignition of this material.Two hours’ heating of the soil at 450° C. or about half an hour at 500° C. are recommended for the removal of 99% of the soil organic matter.


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