This paper presents a new method to calculate the freshwater target for water using networks with single contaminant. The pinch point is determined by exploiting one of the features of water-pinch-analysis: freshwater is only necessary below the pinch. With the known pinch point, the calculation of the freshwater target becomes very simple, especially for the networks with many streams. The res...

Uptake of nutrients and organic C was measured once annually between 2000 and 2002 in each of 10 streams within the water-supply source areas for New York City. Nutrients (PO4 3– and NH4 þ) and organic C (glucose and arabinose) were injected into the streams for 1 to 2 h, and uptake lengths were estimated from the longitudinal declines in downstream concentration relative to that of a conservat...

clustering technique is one of the most important techniques of data mining and is the branch of multivariate statistical analysis and a method for grouping similar data in to same clusters. with the databases getting bigger, the researchers try to find efficient and effective clustering methods so that they can make fast and real decisions. thus, in this paper, we proposed an improved ant syst...

Semiaquatic flies (Diptera, Nematocera) are an ecologically important and species rich group of insects within the boreal and arctic biomes. Community structure, species richness and abundance of semiaquatic flies were studied in three habitat types (aapa mires, springs and headwater streams), totaling 19 study sites, within the subalpine ecoregion of northern boreal Finland. Concordance of sem...

Chitin, a biopolymer present in fungi and arthropods, is compound of interest for various applications, such as the agricultural medical fields. With recently growing development insect farming, availability chitin-containing residual streams, particularly molting skins (exuviae), expected to increase near future. For application purposes, accurate quantification chitin these sources essential....

Streams and rivers regulate nitrogen transport (N) to downstream ecosystems. Rates of N uptake can be high in streams, but controls on the variation in uptake rates of N among streams are not known. We measured ammonium (NH ) and nitrate (NO ) uptake velocities (Vf) and compared these with whole-reach estimates of gross primary 1 2 4 3 production (GPP) and community respiration (CR) in 11 low-n...

conclusions the results of this study show that it is possible to remove nitrate, and its intermediates from waste water. regarding the desirability of the process, the field scale study is proposed. results the results showed that by applying electric current of 0.14 a for 120 minutes, the nitrate content would reduce down to 97%. the obtained r2 for the nitrate removal model was higher than 0...

Ghale-madreseh is the first point that the saline and sulfurous streams flow into Tembi River, one of the well-known saline rivers in Khuzestan province, Iran. This river is one of the main sources of increasing Karun River’s salinity, which is the largest river in Iran in terms of discharge. There are three saline and sulfurous springs (Shour-1, Shour-2m and Namak Springs) as well as a drinkab...

We describe a three step process for the removal of uranium (U) from dilute waste waters. Step one involves the sequestration of U on, in, and around aquatic plants such as algae. Cell wall ligands efficiently remove U(VI) from waste water. Growing algae continuously renew the cellular surface area. Step 2 is the removal of U-algal particulates from the water column to the sediments. Step 3 inv...