Comparison of technology, costs and environmental benefit of wastewater treatment plants in mountainous areas in the alps

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Brandenburg Refuge

Site description and boundary conditions
Design and treatment efficiency

Site description and boundary conditions

boundary conditions
maximum daily organic load [PE]	61
maximum hydraulic load [m3/d]	0.37
annual organic load [kg BOD/a]	90
altitude [m a.s.l.]	3274
sensitivity [hydrogeology, protected area ...]	granite
lagal requirements [BOD elimination]	40 %
operation period [season]	summer
energy supply [type, kW]	Aggregate
means of transport [type]	helicopter
existing WWTP [type, condition, volume l/PE]	no facilities

Fig. 4.4: View on the Brandenburg Refuge with a solar collector installed on the roof for hot water preperation and heated sludge composting.

 

Fig. 4.5: Compost chamber in a small incubated and heated room below the dry toilets.

Design and treatment efficiency

Loading of biological treatment

WWTP Brandenburg Refuge	seasonal average	max. week	max. day
loading [PE60]	16	50	61
BOD5-load  [kg/d]	1.0	3.0	3.66
influent flow Q [m3/d]	0.2	0.3	0.37

   

Design according to the F/M ratio in the max. week

Mtotal, wet = 240 g/PE60 x 1.400 EW60 x 3 = ca. 1.000 kg/a (total separated solids) Factor 3 for added composting material (straw, sawdust,...) Two compost toiletts with about 500 kg compost each Mtotal, stabilized = ca. 300 kg/a (composted sludge considering evaporation)

Energy demand

Heating of the compost room by solar collector and over with heat exchange => hot water heating system

 

Treatment efficiency

date [dd.mm.yyyy]	dry matter [weight %]	organic content [weight %]	temperature [°C]	loading [% of PEmax]
25.07.1999	63	89	40	--
25.08.2000	51	79	--	44
06.08.2001	31 - 35	71 - 81	43	31