Suspended matter, major cations and dissolved silicon in the estuarine waters of the Mahanadi River, India

Dissolved silicon and its isotopes in the water column of the Bay of Bengal: Internal cycling versus lateral transport

“…It is noteworthy that productivity in these near surface waters is not limited by light attenuation caused by high turbidity. The concentrations of dissolved Si measured in this study from the northern shelf waters are comparable to those reported earlier at similar salinities of $24.5 to 32.2 (Ray et al, 1984;Carroll et al, 1993;Somayajulu et al, 2002). Earlier studies (Ray et al, 1984;Carroll et al, 1993;Somayajulu et al, 2002) that investigated two endmember mixing between river water and seawater in BoB estuaries, have suggested removal of dissolved Si from low and mid salinity (615) regions of the estuary, followed by a near conservative mixing up to salinity $32 of surface waters in the northern BoB.…”

Behavior of major and minor elements in a temperate river estuary to the coastal sea

“…Such types of behavior of the major elements are very similar to the observation in the Indian Subcontinent rivers (Ray et al 1984;Subramanian and Jha 1988;Ramanathan et al 1993;Sharma et al 2007). Sodium (Na) was lower in concentrations because of its preferential absorption and incorporation onto silicates (SiO 2 ).…”

Geochemical cycling in the Hooghly estuary, India

“…Despite these activities, the particulate contents of the Hooghly estuarine waters are comparable to the values reported for Meghna estuary during the month of February, viz. 200 F 20 mg l À 1 (Barua, 1990) and also for those of Mahanadi and Godavari during the non-monsoon periods (Ray et al, 1984;Sarin et al, 1985). It should be noted here that December being a non-monsoon month, wherein the suspended matter, like in all Indian rivers, is much lower compared to the monsoon months, viz.…”

“…It should be pointed out that all sampling of the Hooghly estuarine and the Bay of Bengal waters was done during the winter (December -February). Based on the studies hitherto conducted, it can be said that except for the monsoon (high flow during June -September) when the concentrations of elements and/or U -Th series isotopes are low, there is not much change in the chemical characteristics during the rest of the year (Sarin, 1983;Ray et al, 1984).…”

“…228 Ra has been used as a tracer for surfacewater mixing in the Bay of Bengal (Rengarajan et al, 2002). Such a release can also be due to groundwater, (Moore, 1997) and Indian rivers during non-monsoon season have a significant component of subsurface waters (Sarin, 1983;Ray et al, 1984). U and Th series nuclides serve as excellent tracers for understanding the nature and time scales of geochemical cycling involving adsorption of reactive elements onto particles from water, release/desorption of passive elements from suspended matter and estuarine sediments, and mixing of water, within the deltaic region and beyond, in the Bay of Bengal.…”