Alligator Rivers region regional surface water quality monitoring : November 1978 - April 1981
Alligator Rivers Region - Regional Surface Water Quality Monitoring, Volumes 1,2,3 (Plus draft)
Northern Territory. Department of Transport and Works. Water Division, Environmental Section
E-Publications; E-Books; PublicationNT; Report ; 49/1983
1983-04-01
At head of title: Water Division, Dept. of Transport & Works, Northern Territory. "April 1983".
English
Water quality -- Northern Territory -- Alligator Rivers Region; Hydrology -- Northern Territory -- Alligator Rivers Region
Northern Territory Government
Darwin
Report ; 49/1983
3 volumes. ; 30 cm
application/pdf
Attribution International 4.0 (CC BY 4.0)
Northern Territory Government
https://creativecommons.org/licenses/by/4.0
https://hdl.handle.net/10070/672725 [Alligator Rivers region regional surface water quality monitoring : November 1978 - April 1981 - WRD83049_v_1.pdf]; https://hdl.handle.net/10070/672727 [Alligator Rivers region regional surface water quality monitoring : November 1978 - April 1981 - WRD83049_v_2.pdf]; https://hdl.handle.net/10070/672729 [Alligator Rivers region regional surface water quality monitoring : November 1978 - April 1981 - WRD83049_v_3.pdf]
https://hdl.handle.net/10070/229664
https://hdl.handle.net/10070/672725
https://hdl.handle.net/10070/672729; https://hdl.handle.net/10070/672727
Technical Report WRD83049 Viewed at 14:07:10 on 29/07/2010 Page 29 of 440. I I I I I I I I I I I I I 1 I I I I I I Total Phosphorous Hardness Calculated hardness Carbonate hardr1ess Non-Carbonate hardness Total alkalinity Sodium to total cation ratio Silica Chlorophyll and pheophytin 28. This term includes phosphate P (above) plus that locked into organic matter. This may again become available after decomposition of organic matter. No special preservation techniques are required. This was orginally designed as a measure of the capacity of the '"ater to precipitate soap, and since this is caused principally by calcium and magnesium these are the main parameters of interest. Other parfu~eters of interest are polyvalent cations but these are negligible in most cases. A large number of descriptions are used and these are all expressed in terms of calcium carbonate. This is a mathematical expression of polyvalent ions as CaC0 3 ; Ca concentration is multiplied by 2.497 and Mg concentration is multiplied by 4.116, and their sum will give a calculated hardness. These a~alyses are similar, along with carbonate and bicarbonate (which are alkalinities), and are based on pH titrations. The comparison of hardness (titration) with alkalinity, defines the type of hardness (or alkalinity). The analysis has ~he disadvantage of depending upon pH which may change bet;o;een Sfu-npling and analysis. This is a calculation reflecting the ion balance of the solution. It may be particularly useful when trying to predict the source of water or contamination; eg from seawater, groundwater or other sources. Silica found in waters is expected to be primarily derived from diatoms. Other minor sources are from minerals, but it is generally only considered as a nutrient measurement. It causes problems when stored and is often analysed on a chilled sample only, as freezing may facilitate precipitation of dissolved silica. These (or more specifically chlorophyll) are considered as algal biomass indicators. Pheophytin is analysed mainly as a correction factor for chlorophyll. These analyses were requested by the oss to assist in projects carried out by the Research Institute.