A. INSTALLATION GUIDE 2. OPERATING PRINCIPLE OF ECOROCK-5000 UNITS
PAGE
8 / 51
Installation and User guide – ECOROCK - Systems – 26-05-2016
2.
Operating principle of an ECOROCK® Sewage Treatment Plant
2.1 THE PRIMARY TANK
2.1.1
Ventilation of the Primary Tank
Any Primary tank should have a proper unencumbered low level and high level vent. The low level
vent should be connected directly on the outlet side of the tank and the high level on the inlet side
and should not be positioned more than 10 m
1
from the tank and at a minimum height of 4 m
1
with
a wind driven ventilator also fitted. The water inlet should be made air tight. All ventilation should
be checked with a smoke test.
2.1.2
Performance of the Primary Tanks (PT)
If you don’t use a Primary Tank of BIOROCK, you have to make sure that the quality of the effluent
of the PT meets the BIOROCK requirements. A proper ventilation of a PT is necessary, not only to
avoid smell problems, but also to evacuate the produced gasses. A Primary Tank generates
malodorous gases like sulfur hydrogen (H
2
S). An evacuation of the gasses is necessary to avoid that
H
2
S will be transformed into harmful sulfuric acid (H
2
SO
4
). sulfuric acid will harm the biological
process and can cause degradation of the BIOROCK Media.
BIOROCK claims the following performance of a PT in front of a BIOROCK unit:
Composition of normal domestic wastewater (according to EN12566-3+A2 Annex B.3.2):
Variation
BOD
5
*
1
:
150 - 500
mg O
2
/l
COD*
1
:
300 – 1000
mg/l
S.S.:
200 - 700
mg/l
KN:
25 - 100
mg/l
NH
4
-N:
22 - 80
mg/l
P-Total:
5 - 20
mg/l
*
1
: The ration between BOD
5
and COD should always be < 2
Minimum performance requirements of a Primary Tank*
2
:
Effluent PT
Average
EN 12566-6: 2008
BOD
5
:
100 - 350
mg O
2
/l
200 ± 50
mg O
2
/l
COD:
200 - 600
mg/l
S.S.:
40 - 150
mg/l
80 ± 20
mg/l
KN:
35 - 100
mg/l
NH
4
-N:
30 - 80
mg/l
P-Total:
4 - 20
mg/l
*
2
: The sampling should be done with a minimum 24 hour sampling
The effluent is easy biodegradable if the ratio of BOD
5
and COD is less than 2. Between 2 and 3 it is
partially biodegradable and greater than 3, the effluent is not biodegradable.
