Phosphorus Cycling between Sediment and Overlying Water in Ben Chifely Reservoir, Australia under Simulated Core Incubation

The flux of soluble reactive phosphorus (SRP) was estimated under simulated oxic, anoxic and aerated conditions in sediment cores collected from two sites in a meso-eutrophic reservoir that differ in depth and limnological characteristics. Hypolimnetic accumulation and the concentration of P in various sediment fractions were also studied to determine the factors and processes influencing SRP flux at the sediment-water interface. The average release of SRP under anoxic incubation varied between 16 - 70 µmol/m2/day and 20 - 94 µmol/m2/day in shallow and deep-water sites respectively. On the other hand, SRP was almost entirely lost to the sediment during simulated oxic or aerated experiments. Temperature influence on P release from the sediment was significant and the increment is considerable at water temperature above 20oC. The reservoir sediment contained a large proportion of iron and aluminum bound P (Fe and Al-P). Fe and P ratio in the sediment exceeded 15 indicating high retention capacity of P by the sediment. Besides, the high amount of Fe and Al-P in the sediment reflects redox dependent P mobilization. Therefore, management needs targeting retention capacity of the sediment and alteration of anoxic condition in the hypolimnion during warmer months

A study on selected water quality parameters along the river Buriganga, Bangladesh

The Buriganga river system is located in the southern part of the north central region of Bangladesh, passing through west and south of Dhaka, the capital of Bangladesh. The river receives wastewater from numerous numbers of sources along its way, which are discharged as industrial effluents, municipal sewage, household wastes, clinical wastes and oils. The purpose of this study is to investigate into the impact of this wastewater on the river water and thus to provide an updated report on the state of water quality of the river Buriganga. The water samples were collected in year 2008-09 during both dry and wet seasons from different points along the river and analysed for various physiochemical quality parameters, which includes: temperature, pH, EC, DO, BOD , COD, PO -P, NH -N, Pb and Cr. The mean values for the parameters in both dry and wet seasons were compared with the surface water quality standards as set by the Department of Environment (DOE) in Bangladesh. The water quality test results have also been summarised and presented through box and whisker plots