Determining the general oxidizability of water by means of a titrometric liquid analyzer
- PDF / 169,239 Bytes
- 2 Pages / 612 x 774 pts Page_size
- 72 Downloads / 130 Views
.
Yu. B. Sekanov, Methodological Recommendations for Calibrating Electrical Grain Moisture Meters, All-Union Scientific-Research Institute for the Mechanization of Agriculture, VIM, Moscow (1973). N. V. Smirnov and I. V. Dunin-Barkovskii, Short Course of Mathematical Statistics for Technical Applications [in Russian], Fizmatgiz, Moscow (1959).
DETERMINING THE GENERAL OXIDIZABILITY OF WATER BY MEANS OF A TITROMETRIC LIQUID ANALYZER L. S. Tereshina and E. M. Malkova
UDC 543.3:543.872
In order to solve a number of most important problems concerning the supplying of water, purifying reservoirs, determining the efficiency of methods for testing effluents in various enterprises of the chemical, metallurgical, and textile industries it is necessary to know the content of organic substances in water, the so-called oxidizability of water, which is normally expressed in grams of oxygen per liter of water. Thepermanganate method for determining water oxidizability is widely used in laboratory practice in accordance with the standard [i]. Investigations of SoViet and foreign authors have shown that the most complete oxidation of organic substances dissolved in water is attained by means of the bichromatic method, which at present is becoming increasingly widespread [2-6]. Both methods are visual and require a long time for analyzing samples [7]. Owihg to a general intensification of production processes, the automatic testing of raw materials, finished products, and production effluents has become a pressing problem. The Dzerzhinskii branch of the Experimental and Design Office for Automation (OKBA) developed a laboratory semiautomatic cyclic titrator type TPL-3 for determining water oxidizabi!ity in the range of 0-450 g/liter Oz. The operation of this instrument is based on the bichromatic method for oxidizing organic substances with the end point of titration being indicated potentiometrically. The instrument is suitable for application in scientific research, workshop, epidemiological-sanitation, biological, and other laboratories for controlling the pollution of effluent, drinking, and natural water. The titrator consists structurally of the following units and assemblies: hatcher, unit for feeding the titrating solution, heater, cells, control unit, and instruction unit. The heater is~filled with the analyzed water sample of i or I0 ml (depending on the content of organic admixtures in the water). All the remaining operations in the instrument are carried out automatically. A given volume of a chromium sulfide mixture is fed in batches to the heater and boiled for i0 min together with the water sample. The contents of the heater are then washed off into the cell where the surplus potassium bichromate is titrated with Mohr's salt which is batched by means of a syringe burette. At the end of titration the system is washed out. The results of the analysis are registered on a counter calibrated in grams of oxygen per liter. Experiments have shown that it is advisable to determine the basic error of this instrument by comp
Data Loading...
