Study On Rapid And Automated Methods For Detection Of Chromium, Manganese, Sulfate In Water

As the society advancing and economic developing, water pollutionbecomes increasingly serious. Because of suffering frequent pollutionaccidents in recent years, the general methods cannot meet the demands of theemergency monitoring, field detection, environmental authorities’s routinemonitoring and the factories’s rapid and automated detection. Therefore, it isnecessary to develop methods for simple, fast, low reagent consumption, highprecision and high accuracy. Metal ions and inorganic nonmetal ions, whichpresented in wastewater, were employed to estimate the pollutant level of thewastwater. Chromium(VI), total chromium, manganese(II), sulfate asimportant pollutants that affect human health, which are important parametersin the routine analysis of water quality. In order to meet the requirements ofdetermination, the rapid and automated detection of chromium, manganeseand sulfate were established in this thesis.1. The rapid determination methods of chromium(VI) and total chromiumwere described. At the same time,the flow injection analysis (FIA) method ofchromium(VI) was described. Interference of ferrous iron and ferric iron ondetermination was solved. Given the rapid and automated detectionrequirements, determination of chromium(VI) and total chromium in waterwas improved based on the DPC spectrophotometric method, The rapidmethod simplified the determination of the steps, reduced the experimentaldifficulty, shortened the reaction time. The combination method of FIA andDPC simplified the flow path of the sample by using mixture acid solution ascarrier. A linear range of0.02~4.0mg·L-1was obtained.2. The rapid and the flow injection analysis determination method ofmanganese (II) was described. In order to eliminate the interference of Ca2+,we added sodium citrate into buffer solution. For portability, the buffersolution and chromogenic agent were made into reagent kits. Furthermore. The automatic method was set up by FIA combined with potassium periodatespectrophotometric method.3. Barium sulfate turbidimetry for determine sulfate was improved andoptimized. the rapid determination method of sulfate was described.4. The program design of the multi-parameter water quality monitoringinstrument was studid. The water quality parameters, including chromium(VI),total chromium, manganese(II), total manganese, soluble copper, toble copper,nickel, sulfate, nitrate, nitrite, nitrogen, ammonia, total nitrogen, solubleorthophosphate, total phosphorus, solubility total phosphorus and chroma,were designed to simple determination. It simplified the determination methodand reduced the difficulty of operation with the multi-parameter water qualitymonitoring instrument. The determinated values can be displayed directly inPLC screen.