This method describes how to measure the surface tension of wastewater using a tensiometer.
Wastewater generated in the industrial production of beer and food
The force measured in this analysis is exerted by the surface tension. The surface tension can be measured either as the force on a plate oriented perpendicular to the surface of the liquid and thoroughly wetted by it (static method) or the force that is required in order to pull out a horizontally suspended rod or ring from the liquid surface (quasi-static method).
Wastewater generated in the industrial production of beer and food
The water sample is diluted with oxygen-rich water “free of oxidizable organic substances” so that after the incubation period there is still at least 2 mg oxygen per liter left in the water. Afterward, the dissolved oxygen in the diluted sample should be determined immediately and then again after five days using an iodometric method or with oxygen electrodes. The difference between the two values yields the BOD5 (taking into account the dilution factor).
This method describes how to collect a sample of wastewater.
Wastewater generated in the industrial production of beer and food
Wastewater samples are collected at regular intervals over a long period of time and combined to create composite samples.
Determination of organic acids using ion chromatography
This method is suitable for beer, wort, green beer, NAB, water and wastewater
Separation by ion chromatography followed by conductivity detection.
Wastewater generated in the industrial production of beer and food
Well-mixed wastewater is poured into an Imhoff funnel, and the volume of sludge is recorded using the volumetric scale on the graduated cylinder after a settling time of two hours.
After decanting the supernatant, the deposits are quantitatively transferred to a platinum dish in which, after drying at 105 °C, the dry residue after evaporation is determined by weight.
After annealing in a muffle furnace at 550 °C for 30 min, the ash content is determined gravimetrically.
The annealing losses are calculated from the difference in weight between the dry residue after evaporation and the ash content.
This method describes the determination of the chemical oxygen demand in wastewater photometrically with a cuvette test.
Oxidizable substances in the water sample react with the sulfuric acid potassium dichromate solution in the presence of silver sulfate as a catalyst. Chloride is masked with mercury sulfate. The decrease in the yellow color of Cr6+ is measured.