scholarly journals ON THE OCCURRENCE OF CHAETOGNATHS IN THE TANSHUI RIVER ESTUARY OF NORTHERN TAIWAN (FORMOSA)

1967 ◽  
Vol 15 (1) ◽  
pp. 5-18 ◽  
Author(s):  
Wen Kuang Liaw
2011 ◽  
Vol 62 (8) ◽  
pp. 1809-1813 ◽  
Author(s):  
Chia-Hui Wang ◽  
Chih-Chieh Hsu ◽  
Wann-Nian Tzeng ◽  
Chen-Feng You ◽  
Chih-Wei Chang

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3075
Author(s):  
Tien-Hsi Fang ◽  
Cheng-Wen Wang

The Danshuei River Estuary (DRE) in northern Taiwan is a seriously eutrophic estuary due to the domestic effluent discharge. Surface sediment samples were collected from the DRE to study the concentrations and spatial distributions of different fractions of phosphorus through the five-step sequential extraction method which chemically divides the sedimentary P into five fractions: PSORB, PCDB, PCFA, PDET, and PORG. The Fe and Mn contents in the extracted solution were also determined. The total organic carbon (TOC) and grain size in sediment samples were analyzed as well. The sedimentary total P (TP) concentrations ranged within 537–1310 mg/kg and mostly exceeded 800 mg/kg, suggesting that the DRE sediments were moderately polluted by phosphorus. The PCDB was the dominant fraction of P, averagely contributing 58% of TP, followed by PDET 31%. The contributions of the PSORB and PCFA fractions to the TP were relatively minor. Two fractions, FeCDB and FeORG, of sedimentary Fe equally shared approximately 70% of total Fe, followed by FeDET with 22%. The contribution of different fractions of sedimentary Mn followed the sequence: MnCDB (36%) > MnCFA (29%) > MnORG (14.7%) > MnDET (14.5%) > MnSORB (5.3%). The sedimentary P, Fe, and Mn within the DRE are easily mobilized because they were mainly present in the reducible fraction. The concentrations of sedimentary TP positively correlated with the TOC contents and inversely negatively correlated with grain size, suggesting that the TOC and grain size play the crucial roles in influencing the distribution of sedimentary P within the DRE. Finally, the Fe(III) (hydro)oxides seems to play an important carriers to adsorb dissolved P because PCDB positively correlated with FeCDB.


1995 ◽  
Vol 46 (1) ◽  
pp. 383 ◽  
Author(s):  
CH Tsai ◽  
SC Hwang

Experiments on the flocculation of fine-grained sediments from the Tanshui River estuary, Taiwan, were carried out. The effects of fluid shear, sediment concentration and salinity on floc growth were investigated. The ranges of these parameters were 12.5 to 400 s-1 for the shear, 50 to 600 mg L-1 for the sediments concentration and 0% to 100% sea water for the salinity. The results showed the following. (1) The time required to reach a steady state ranges from 2 to 44 h and median floc sizes range from 100 to 520 μm. (2) The steady-state median floc size decreases with the increase in sediment concentration. (3) The floc size increases as the shear increases. (4) Increasing the proportion of sea water from 0% to 50% decreases the floc size to one-fourth of that of freshwater flocs, and a further increase in salinity does not decrease floc size significantly. (5) The time required to reach a steady state decreases with the decrease in shear, the increase in sediment concentration and the increase in salinity. (6) The larger the steady-state flocs, the longer they take to form. Comparison of these results with those obtained in similar studies of Lake Erie sediments shows that the flocculation properties of Tanshui sediments are substantially different from those of Lake Erie sediments. Tanshui sediments are much more difficult to aggregate, but once flocs are formed they are larger. The reasons why different types of sediment behave differently should be studied further.


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