The Algal-Bacterial Selenium Removal (ABSR) system has been very effective at removing Selenium from agricultural drainage water that enters the water systems of the San Joaquin Valley, CA. Although selenium levels are significantly lower in the effluent of the ABSR system, Dissolved Oxygen (DO) levels in effluent water have been found to be significantly lower than normal. If DO levels dip und...

Assays were carried out to evaluate effects of detritus size on the mineralization of an aquatic macrophyte, the Oxycaryum cubense. Samples of plant and water were collected from an oxbow lake, the Infernão lagoon (21 degrees 35' S and 47 degrees 51' W) located at Mogi Guaçu river floodplain. The plants were taken to the laboratory, washed under tap water, dried (50 degrees C) and fractioned in...

Hyporheic exchange carries reactive solutes, which may include biological oxygen demand (BOD), dissolved oxygen (DO) and reactive dissolved inorganic nitrogen (Nr), into the sediment, where biochemical reactions consume DO. Here, we study the impact of streambed morphology, stream-reactive solute loads and their diel oscillations on the DO benthic uptake rate (BUR) due to hyporheic processes. O...

Water contains oxygen which may make a human breathe under water like a fish. Centrifugal separator can separate dissolved gases from water. Carrier solution can increase the separation of dissolved oxygen from water. But, to develop an breathing device for a human under water, the enhancement of separation of dissolved gases including oxygen and portable devices which have dc battery based dev...

Intensive data collection and a modeling study have been underway for the past several years addressing two of the channel estuaries draining into the Gulf of Fonseca, Estero El Pedregal and Estero San Bernardo. Data have been compiled on the shrimp farm configurations, exchange rates, and effluent chemistry. Temperature, salinity, and dissolved oxygen profiles have been measured in the estuary...

The effects of dissolved oxygen on simultaneous nitrification and denitrification were evaluated in polyurethane foam contact oxidation reactors in a municipal wastewater treatment process. It was observed that nitrate could be removed at low dissolved oxygen levels, but the removal rate was gradually reduced as the dissolved oxygen concentration increased to a higher level of 6.0 mg/L. Nitroge...

Development and modifications of mathematical models for Dissolved Oxygen (DO) are reviewed in this paper. The field and laboratory methods to estimate the kinetics of Carbonaceous Biochemical Oxygen Demand (CBOD) and Nitrogenous Biochemical Oxygen Demand (NBOD) are also presented. This review also includes recent approaches of BOD and DO modeling beside the conventional ones alongwith their ap...

Water contains oxygen which may make a human breathe under water like a fish. Centrifugal separator can separate dissolved gases from water. Carrier solution can increase the separation of dissolved oxygen from water. But, to develop an breathing device for a human under water, the enhancement of separation of dissolved gases including oxygen and portable devices which have dc battery based dev...

Nucleic acids are routinely and readily analysed using the A(260)/A(280) ratio, although this method is known to be prone to erroneous results owing to contaminants in solution that absorb at similar wavelengths. The aim of the present review, while highlighting the problems and alternatives of using UV spectrophotometry for nucleic acid measurements, is to bring forth an observational result f...

background: dams are one of the most important manmade buildings to provide of drinking water. in order to manage of water quality in dams reservoirs, the recognition of phenomena that occurred in it is essential. thermal stratification is one of the major problems that decrease the water quality of dam. the aim of this study was to investigate thermal stratification of ekbatan dam (hamadan) as...