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Fermentors and Operation of Fermentation Equipment
Published in Nduka Okafor, Benedict C. Okeke, Modern Industrial Microbiology and Biotechnology, 2017
Nduka Okafor, Benedict C. Okeke
Of the chemical methods, the best known is the Winkler titration which is routinely used to determine the biochemical oxygen demand (B.O.D.) of water. This method relies on the back-titration of unoxidized manganese salt added to the liquid to be analyzed using iodine and starch. Interfering substances are usually present in fermentation broths. Furthermore, the method is cumbersome. Modern sensing methods sample the dissolved oxygen (DO) in the medium. Modern dissolved oxygen probes are autoclavable and are based on one or the other of two principles: the polarographic or the galvanic method.
Ambient Water-Quality Monitoring in the Willamette River Basin
Published in Antonius Laenen, David A. Dunnette, River Quality, 2018
Samples are analyzed immediately after collection for the field parameters listed in Table 1. Calibration log books are maintained for all field instruments. Instruments are checked and calibrated prior to leaving the lab and at least once daily while in the field. Dissolved oxygen is determined by Winkler Titration. Chlorophyll a samples are filtered in the field and frozen on dry ice immediately. Samples for dissolved analyses are field filtered. Samples are preserved according to analytical protocols, put on ice, and then shipped to the lab.
Water quality
Published in David Butler†, John W. Davies††, Urban Drainage, 2000
David Butler†, John W. Davies††
Dissolved oxygen (DO) can be measured analytically using the Winkler titration method. Titration is a laboratory technique where measured volumes of a reagent (the titrant) are incrementally added to a sample up to the equivalent amount of the constituent being analysed. Membrane electrodes are now more commonly and conveniently used both in the laboratory and for in situ measurements.
Water quality assessment using overall index of pollution in riverbed-mining area of Ganga-River Haridwar, India
Published in Water Science, 2019
Water samples were collected from all the selected five sampling sites (S1–S5) bi-monthly by grab sampling method from June 2017 to May 2018. A total of twenty-four samplings was performed during the study period. The water samples were collected in the polyethylene bottles at the depth of 15–20 cm below the surface water. A total of thirteen physicochemical parameters were being analyzed in the laboratory for assessing the surface water quality. The Water Temperature, Conductivity, pH, and TDS were measured by TOSHCON electrochemical analyzer, TMULTI 27; Italy at the sampling location. Analytical parameters like Alkalinity, Total Hardness, Calcium, Magnesium, Dissolve Oxygen (DO) & BOD (Winkler titration method) were analyzed in the laboratory following the standard methods (APHA, 2012; Trivedy & Goel, 1986). Sodium and Potassium were estimated using Microprocessor Flame Photometer (ESICO) Model 1382. The measurement of all the parameters was done in triplicate and the mean value was presented in the table. For this study, the monthly data of water sample was formulated into seasonal data, monsoon (June–September), winter (October–January), and summer (February–May).
Advances in the development of Cu(I) complexes as optical oxygen-sensitive probes
Published in Journal of Coordination Chemistry, 2022
Hongcui Yu, Bo Yu, Yajiao Song
Molecular oxygen (O2) is an immensely important chemical species because it has practical significance in various applications from biological sciences to environmental and ecological engineering. Determination of oxygen levels is required in many fields, including clinical analysis, molecular biotechnology, food packaging, environmental monitoring, etc. [1, 2]. Unlike many other molecules, O2 is a small, non-polar, paramagnetic molecular structure. The unique electronic structure and properties of oxygen make it very difficult to check directly. Therefore, special “indicator substances” are used to carry out selective and sensitive detection of O2 in complex samples, and data signals that are characteristic and easy to detect can be created without complicated collection and resolution procedures [3]. Since the pioneering studies of Kautsky and coworkers in the 1930s [4, 5], this sensor technology has undergone major development and diversification. Subsequently, considerable efforts have been devoted to developing reliable oxygen concentration measurement technology for many years. Several oxygen detection methods have been developed, which can be classified based on the principle used in traditional Winkler titration, electro-analytical, pressure-based, and optical methods. An optical technique for determining oxygen is based on the idea that the excited state of oxygen-sensitive probes (OSPs) will be quenched by being close to oxygen molecules. Compared with the other three methods, the optical technique has drawn interest because of its non-invasive operation, sensitivity, low detection limits, no O2 consumption, and can enable remote control and micro-area O2 detection under special circumstances [6–8].
Evaluation of the relationship of picoplankton and viruses to environmental variables in a lagoon system (Çakalburnu Lagoon, Turkey)
Published in Chemistry and Ecology, 2018
Guzel Yucel-Gier, Aslı Kacar, L. Tolga Gonul, Idil Pazi, Filiz Kucuksezgin, Neslihan Erarslanoglu, S. Kubra Toker
The temperature, salinity and pH measurements of surface waters were performed in situ using a HACH (HQ4OD) multi-parameter portable system. Dissolved oxygen in the surface water was measured by using the Winkler titration method. Total suspended solids (TSS), which is a parameter for water quality, is the dry-weight of particles trapped by a filter.