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

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Hermann von Barth Refuge

Site description and boundary conditions
Design and treatment efficiency  

Site description and boundary conditions

boundary conditions
maximum daily organic load [PE]	84
maximum hydraulic load [m3/d]	5.1
annual organic load [kg BOD/a]	140
altitude [m a.s.l.]	2129
sensitivity [hydrogeology, protected area ...]	limestone
lagal requirements [BOD elimination]	80 %
operation period [season]	summer
energy supply [type, kW]	photovoltaic, aggregate
means of transport [type]	supply cable car
existing WWTP [type, condition, volume l/PE]	no facilities

 

Fig. 4.17: Flow-scheme of the WWTP Hermann von Barth Refuge

Fig. 4.18: Building with the mechanical solids separator and the solar collector for the hot-air heating of the composting room.

 

Fig. 4.19: Feed screw and dosage equipment (compost aid like saw dust) of the mechanical solids separator and 2 compostainers.

Design and treatment efficiency

Loading of biological treatme

WWTP Hermann von Barth Refuge	saisonal average	max. week	max. day
loading [PE60]	22	6.5	84
BOD5-loadt [kg/d]	1.33	3.9	5.04
influent flow Q [m3/d]	.14	4.1	5.1

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

Mtotal,wet = 240 g/PE60 * 2.335 PE60 * 1.5 = ca. 840 kg/a (total separated solids ) Factor 1.5 for added composting material (straw, sawdust,...) Two compost toiletts with about 500 kg compost each Mtotal, stabilized = ca. 345 kg/a (composted sludge considering evaporation)

Energy demand

max. power [W]	max. electric work [kWh/d]	mean electric work [kWh/d]
280	0.14	0.08

Treatment efficiency

date [dd.mm.yyyy]	dry matter [weight %]	organic content [weight %]	temperature [°C]	loading [% of PEmax ]
05.09.1999	49	90.7	15	--
09.-10.09.2000	19.6	91	14	161
23.09.2001	22.4	88	31	75

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