AURO-Environmental-declaration-2014-04.2019

29 0 1 2 3 4 5 2009 2010 2011 2012 2013 % 4,06 3,76 3,07 2,32 2,75 Waste water Due to the long-term experience with the waste water pretreatment facility and the use of a different flocculation agent, the threshold values have not been exceeded since 1992. The discharge parameters prescribed in the corresponding administrative orders of the municipality of Braunschweig could be substantially reduced. The comparably high amount of waste water in the year 2010 results from the abundant rainfalls accounting for 89 % of the total figures. Another input on the energy and material balance is the rain water filling station that has been saving expenses since it was put into operation. Waste and other output All waste materials are collected separately and disposed of as household gar- bage, recycling material or as special waste. The detailed separation and docu- mentation of the waste quantity has led to a steady rise of the overall figures whereas the production specific waste has been regressing continually. Retailers are offered the special service of returning their old, damaged or spoiled products and have them disposed of adequately. In recent years, many customers used this service which is why the quantity of ‘special waste’ increased. It also led to an in- creased amount of metals to be disposed of as recyclable material (emptied tin cans). Since 1996, the paint and varnish sludge from the waste water conditioning facility is brought to a composting plant in nearby Salzwedel where it is mixed with other compost and thus returned into the natural cycle. The waste quotient describes the relation between the output of finished products and the ensuing waste. Waste water As early as 1989, a flocculation and sed- imentation facility was installed for the pretreatment of the rinse water needed for cleaning containers. Otherwise it would have to be disposed of as ‘special waste’. Because of the caustic potash used, the untreated waste water is alkaline, with a pH value between 8 and 13. It has a high degree of lipophilic parts and hydrocar- bons and, in comparison with the munic- ipal waste water, a much lower ratio of BOD5 (5 day biochemical oxygen ) to COD (chemical oxygen demand). Per month, 2,5 – 3,5 m 3 of pretreated rinse water are passed into the communal sewer system. Primarily, the municipal- ity of Braunschweig monitors the con- tent of heavy metals and hydrocarbons in the waste water. Chart Waste quotient Energy and raw material – key figures In the future, the recovery of recyclables will get even more important.