| All treatment plants treating industrial effluents have | | | | Another property of this membrane is that it is |
| to cope with the problem posed by nitrate in | | | | immiscible in the solvent, which in this case is a |
| wastewater. It has to be filtered at the earliest | | | | sample of the wastewater used to determine the |
| possible instance as it is highly water soluble and can | | | | presence of nitrate in wastewater. |
| easily contaminate drinking water sources. In this | | | | The wastewater being tested will have a lot of |
| article I tell you about the best way to identify | | | | industrial effluents as impurities. These can hinder the |
| nitrates in wastewater, before eliminating them. | | | | reaction used to determine nitrates in wastewater. |
| The Nitrate Electrode Method | | | | Hence it is necessary to use some kind of buffer |
| The nitrate ion electrode method is one of the way | | | | that will inhibit the action of these impurities on the |
| to ascertain the presence of nitrate in wastewater. | | | | nitrate ion electrode. To do this, sometimes Ag2SO4 |
| During this test the electrode acts as a selective | | | | (silver sulphate) is used as a buffer. This buffer can |
| sensor. It is called 'selective' because it only reacts | | | | nullify the interference of contaminants like the CN |
| with the nitrate ions in the wastewater sample. This | | | | (Cyanide), S (Sulfur), Cl (Chlorine), I and Br (Bromine). |
| reaction occurs at a concentration of 1000 ppm or at | | | | In a similar way the action of the Sulfanic acid can be |
| the ionic activity range of 10m for the solution. | | | | used to neutralize the effects of NO2 (Nitrogen |
| During this activity the nitrate ion electrode has a fine | | | | Dioxide). The aqueous solution of PH3 (Phosphine) |
| membrane like layer of ion exchanger covering it that | | | | though difficult to prepare as it solubility is low, can |
| allows the ions to pass through. This is a result of the | | | | effectively neutralize the effects of HCO3, the |
| potential applied to this electrode. This film like | | | | bicarbonate ions in the sample. Similarly the |
| membrane is itself inert and its only function is to | | | | Al2(SO4)3, Aluminum Sulfate, can nullify the effects |
| work as an ion exchanger. It is porous and hence | | | | of various complex organic acids. |
| allows the ions through to reach the electrode. | | | | |