Recently, hypoxia has become serious in Lake Biwa due to progressing of global warming. In this study, we determined Mn and As concentrations and their speciation in lake bottom water and sediments in June and December to elucidate their geochemical behaviors. Lake bottom water and sediment samples were collected from seven stations in the northern basin of Lake Biwa. In sediments, clear enrich...

Effects of eutrophication on arsenic speciation were studied in eutrophic Lake Kiba and mesotrophic Lake Biwa, Japan. By combining hydride generation atomic absorption spectrometry with ultraviolet irradiation, inorganic, methyl and ultraviolet-labile fractions of arsenic were determined. In both Lakes, inorganic species (As(V+III)) dominated over other forms of arsenic all the year round. Most...

This study presents results from field surveys performed over various seasons in a large, eutrophic, shallow lake (Lake Taihu, China) using an in situ chromophoric dissolved organic matter (CDOM) fluorescence sensor as a surrogate for other water quality parameters. These measurements identified highly significant empirical relationships between CDOM concentration measured using the in situ flu...

Deterioration of concrete, which is mainly due to ignorance of environmental and service conditions, causes considerable costs for the construction industry. With this in mind, in this paper, results of investigation into the major causes of concrete deterioration in the Urumie Lake are presented. For the purposes of this investigation, samples were obtained by mixing two types of cement (OPC t...

Deterioration of concrete, which is mainly due to ignorance of environmental and service conditions, causes considerable costs for the construction industry. With this in mind, in this paper, results of investigation into the major causes of concrete deterioration in the Urumie Lake are presented. For the purposes of this investigation, samples were obtained by mixing two types of cement (OPC t...

We measured the level of heavy metal accumulation in lake sediments, herbivorous (Oreochromis niloticus) and carnivorous (Serranochromis thumbergi) fish, and crayfish (Cherax quadricarinatus) from Lake Itezhi-tezhi (ITT) and Lake Kariba. We used atomic absorption spectrophotometry to quantify the levels of seven heavy metals (Cr, Co, Cu, Zn, Cd, Pb, and Ni). The sediment and the herbivorous fis...

Dynamics of dissolved organic carbon concentration (DOC) and capacity to absorb light (color) are determined by in-lake and external properties and processes. In this study, the influence of external factors such as rainfall and solar radiation on DOC and color dynamics was assessed for a small forested lake. DOC and absorption coefficients at 440 nm (a440) ranged 4-fold from 0.46 to 1.62 mM an...

[1] The absorption and scattering coefficients in the euphotic zone of oligotrophic Lake Taupo, New Zealand, were measured at 19 stations across the 620 km lake in late fall during the period of mixed layer deepening and development of the annual phytoplankton maximum. These coefficients were subsequently related to the water content of colored dissolved organic matter (CDOM), phytoplankton, an...