Chao Phraya River pollution and photosynthetic oxygenation / M. B. Pescod and Tiwa Limsiwawongse
โดย: Pescod, M.B.
ผู้แต่งร่วม: Limsiwawongse, Tiwa
Language: English ชื่อชุด: Res. Proj. No. 34/3 Rep. No. 1ข้อมูลการพิมพ์: Bangkok : Thailand Institute of Scientific and Technological Research, 1967 รายละเอียดตัวเล่ม: 32 p.หัวเรื่อง: Chao Phraya River | Photosynthetic oxygenation | Waste water | Water -- Pollutionสารสนเทศออนไลน์: Click here to access full-text สาระสังเขป: Light and dark bottle studies have shown that photosynthetic oxygen production by phytoplankton is normally in the range from 0.5 to 1.3 mg/1 day at the river surface. This falls off to zero very quickly with the usual depth of the euphotic zone being from 1 to 1.5 m. The gross photosynthetic oxygen production at Memorial Bridge ranged from 0.20 to 0.78 g/m day, whereas the respiration demands for oxygen at the same section at the same times were 16 and 17 g/m day. Thus photosynthesis can supply from 1.25 to 4.6 percent of the oxygen demand at this section of the river. The contribution of oxygen by photosynthesis at other stations on the river should make up a greater proportion of the demand because of the lower depths of the sections Authors' conclusions.สาระสังเขป: Normal conditions in the Chao Phraya River provide a satisfactory environment for algal growth and photosynthesis. Although the numbers of algae in the river water increase to a certain extent with increasing turbidity, the effect of burbidity in reducing light transmission seems to affect adversely the photosynthetic oxygen production. Dissolved oxygen concentrations in the river are closely related to tidal movements. The lowest levels of dissolved oxygen are recorded at high or low water slacks depending upon the location of the station. At an below Bangkok Port the greatest oxygen level occurs at high tide, whilst above the Port the greatest level occurs at low tide. The lowest dissolved oxygen concentration occurs at low river discharge, when the estuary is non-stratified, and, at this time, the river is very close to becoming anaerobic in the reach from Memorial Bridge to the Port. A definite oxygen sag curve is observed at low river flows with depression of dissolved oxygen from Rama VI Bridge to a minimum at or near Memorial Bridge for high tide conditions and Bangkok Port for low tide conditions. Some recovery occurs between the Port and Samut Prakan, towards the river mouth, but this is the result of many days of residence in the estuary. There is evidence to indicate that the river condition is becoming worse each year.
| ชนิดของทรัพยากร | Location | Call number | สถานะ | Last seen | Copy No. | บาร์โค้ด |
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วว. เทคโนธานี | Available | 2018-08-31 | 1 | RP1967/240 | |
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วว. เทคโนธานี | Available | 2018-08-31 | 2 | RP1967/240-2 |
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