Synthetic wastewater, composition

A strain of yeast and a strain of bacterium were co-immobilized to fabricate a biochemical oxygen demand (BOD) sensor based on sol-gel derived composite materials97. This novel type of biosensor was developed for water monitoring and was used to determine the BOD values of OECD synthetic wastewater, domestic wastewater, and lake waters. The microorganisms Trichosporon cutaneum and Bacillus subtilis were coimmobilized in the sol-gel composite material, which was composed of silica and the grafting copolymer of poly (vinyl alcohol) and 4-vinylpyridine (PVA-g-P(4-VP)). 

The influent composition was defined so as to simulate drainage wastewater Ifom a metallurgical industry dam. Thus, the eomposition of this synthetic wastewater presented around 80 mg/L zinc, 2 mg/L cadmium, and 800 mg/L sulfate. Table 1 summarizes the main operational eharacteristics of the experimental runs investigated at 25 2 °C. 

Many research papers have modeled the change in current efficiency based on COD (more rarely TOC) with conversitm, but quantitative correlation is only possible for synthetic wastewaters, whose compositions are known. These hmitations are not an obstacle in the industrial setting, where the total carbon load (kg m ) is more important than the identities of specific contaminants, and the practical objective is to achieve some final objective in terms of the TOC or the COD of the treated solution. The efficiency of the process can then be expressed indirectly, for example, as specific energy consumption (kWh per kg C or per kg COD removed) [6]. 

Commercial synthetic dyes generally contain more than one color product. As the knowledge of the exact composition of dye mixtures is prerequisite for their successful application in many fields of industry and research, many efforts have been devoted for the development of various chromatographic techniques suitable for their separation and quantitative determination. Moreover, the exact determination of the composition and quantity of synthetic dye is required in the control of industrial processes, in the following of efficacy of wastewater treatment, in environmental protection studies, and in forensic science. 

Each of the methods was evaluated initially in the laboratory using known synthetic compositions and then field-tested using actual oily wastewater samples. 

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