Qualifizierungssystem Aktivkohlereaktivierung Stadtwerke Düsseldorf AG

… the details of the returned activated carbon (reactive and fresh carbon). The following information is expected: - Grain size distribution according to EN 12902 - Unevenness coefficient U according to EN 12915-1 - Shaking density or bulk density according to EN 12915-1 (it is mandatory to specify which parameter is determined) - Ball hardness according to EN 12915-1 - Iodine number according to EN 12902 (the activated carbon to be reactivated and the activated carbon without makeup, optionally also the iodine number of the resulting return) - Ash content according to EN 12902 - Indication of the percentage of makeup in the returned coal (corresponds to the burn-off and other process loss) - Designation of the added makeup coal It must be ensured that the collected batch of coal is not mixed with other coals and thus this batch is safely returned. For this purpose, the WG must be provided with a description of the process sequence of reactivation in order to be able to understand this. Fresh grain activated carbon as make-up coal for drinking water treatment on the basis of coconut shells or on the basis of reagglomerated hard coal (both types are tested by the AG) as make-up coal for reactivations with the following properties (all data refer to DIN EN 12902 or DIN EN 12915) - wettability / floating fraction less than or equal to 0.6% (m/m) - grit 8 x 30 mesh (0.6 - 2.36 mm), determined according to DIN EN 12902 - subgrain fraction maximum 5%, overgrain fraction maximum 15% (according to DIN EN 12915-1) - vibrating density approx. 530 kg/m3, bulk density approx. 460 kg/m3, determined according to DIN EN 12915-1 - unevenness coefficient U (d60/d10) should <1, 9, determined in accordance with DIN EN 12902 - Ball hardness >90, determined in accordance with DIN EN 12915-1 - Ash content maximum 15%, determined in accordance with DIN EN 12902 - Water content maximum 5% on delivery - Other impurities and secondary components (see DIN EN 12915-1 point 6.2.2 "Impurities and secondary components" Table 1): max. 3% water-soluble components, max. 0.002 g zinc / g activated carbon, determined according to DIN EN 12902 - maximum contents of water-soluble and water-extractable substances (see DIN EN 12915-1 point 6.2.3 "Water-extractable substances" Table 2): 10 μg/l arsenic, 0.5 μg/l cadmium, 5 μg/l chromium, 0.3 μg/l mercury, 15 μg/l nickel, 5 μg/l lead, 3 μg/l antimony, 3 μg/l selenium, 5 μg/l cyanide, 0.02 μg/l PAH (sum of concentrations of fluoranthene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, benzo(ghi)perylene, indeno(1,2,3-cd)pyrene) for the extinction water - The test methods specified in the relevant DIN EN (12902 and 12915-1) shall be used. If other methods (ATSM, home method) are used, the comparability of the methods used with the test methods specified in DIN EN must be proven. If there is a change in the raw materials (production site) or the production process of the activated carbon, the customer must be informed of the change by the supplier at the latest before a delivery is called up. This applies even if the requirements of the relevant product standard remain unchanged.