Økologisk byfornyelse og spildevandsrensning, 47 – Etablering og drift af anlæg til opsamling, rensning og genanvendelse af gråvand til toiletskyl og maskinvask af tøj - Nordhavnsgården – Bilag C: Rapport for 1. års gennemgang af renseanlægget

Etablering og drift af anlæg til opsamling, rensning og genanvendelse af gråvand til toiletskyl og maskinvask af tøj

Bilag C: Rapport for 1. års gennemgang af renseanlægget

Lokus GmbH - Silbersteinstraße 97 - 12051 Berlin- Neukölln

Moe & Broedsgard AS
c.o. Morten Anderson

Torringvej 7

DK-2610 Rodovre
Denmark

Date: 2.07.02 by: gw / grehl

Maintenance report on graywater recycling plant in Nordhavnsgaarden
Date: Maintenance 1.7.2002

Report on maintenance work in Nordhavnsgaarden,graywater recycling plant (protokoll).

Optical control:
Over all impression: plant room and plant are tidy and seem well maintained

Plant is running normal.
No odour.
No failure indication lamps except the oil change lamp, which comes on after a year
UV-lamp is on, reading,while loading: 138% o.k. but low
The compressed air system is working, no leakage

Primary settling tanks and inflow:
Inflow pipes show no leaks, the valve is working and the backflow preventer shows no sign of bl°Ckage.
The sump shows little sludge, the sump pump is working
The pneumatic drain valve is working properly
The tanks show a little sludge thickness between two and a half centimeter
Reading of sensor is 1920, tanks about half filled, o.k.
The cleansing process is funtioning normal
The feed pump shows no sign of bl°Ckage and is working normal

Bio-rotator-group
Motor and axle o.k.
Oil change after 9872 hours with 3.1 liters gear box oil acc. manufacturers spec.
Bearings o.k., additional greasing with special insoluble grease to prevent corrossion. Speed: 1 rpm, given Jan instructions to increase speed if there is clogging of first rotator.

Aluminium structure o.k.
No leaks or overspill from rotators.
Biologie: First rotator shows a good growth, more threadlike than before, color light,yellowish brown,visibility approx. 20 cm. Sludge on the sides of tank up to 1 cm, threads,o.k. Second rotator shows less growth, color is lighter, visibility is doubled. No growth on the sides. Third rotator shows almost no growth, color tends to light gray, bottom of tank is visible.

From growth structure and increase in visibility it can be deduced that the biological process is working good to very good. The inflow is approx. 5cbm per day, acc. to Jan.

Lamella seperator:
No floatsam on top of seperator, a lot of dark gray sludge on top of overflow pipe, and lamellas, still o.k..
Water marks on the sides show that the backflush is working properly, water level actually at middle of overflow pipe to hold tank o.k.. The increase in backwashing time seems to work.

The hold tank shows about 4 cm of sludge in the right corner, acc. to Jan no cleaning in the last five month, no increase in thickness in the last month. Color: yellow brown on top, dark brown at the bottom, which means that there is no anerob process. The upbuilding of sludge is rather high but tolerable, advice: clean tank if necessary or wanted for estetical reasons, there is no impact of sludge on uv-disinfection detectable and the amount of sludge in the treated water tank is negliable. Details see below.
Changed the fixing of the aluminium structure, to prevent sliding.
No cleaning of filter, so the test for the increase in backwash water is not interrupted

Ultraviolet – disinfection
The device is working, reading about 138 %, rather low. After removing chalk residue from quarz-pipe reading is up to 223 %. After consulting the manufacturers manual, we agreed not to change the lamp until reading is 100 % or below. Manual: at least 40 %. We will be still on the save side, even considering that the figure given is for fresh water. Cycles: 857, no leaks. Alarm test: o.k.
Feed pump: o.k. 1244,2 hours running time, 10721 cycles

Treated water tank
Sensor: o.k., found another small piece of metall (wire rest) in the plug, reading: o.k.
Additional potable water supplie starts/stops automatically.
No sludge in the first tank.
Little sludge in the second tanks back half, thickness up to 2cm approx. normal after 1500 cbm.
Drained and cleaned the seperator chamber, no sludge upbuilding at the bottom.
Drained and cleaned the second tank

Booster system:
Pump inspection: o.k.. Pump 1 137 hours-25083 cycles. Pump 2 134,6 hours- 25054 cycles, o.k.
Incut pressure 2,6 bar, o.k., cut off pressure 4 bar, o.k. Pressure sensor: reading o.k.
Meters: treated water: 579 cbm , potable water: 200 cbm, treated water meter at sink: 893 cbm, potable at sink: 7,3 cbm, energy consumption of plant: 3750 kwh equals 2.55 kwh/cbm, rather high due to simulation (sump pump), average in the last month: 2kwh/cbm (31.5-28.6)

Expansion vessel:
Should: 2,5 bar
Is : app. 2,5 bar - ok

Pipework:
o.k., no signs of corrossion, except for the fixing inside of the bio rotator, feed pipe graywater. The pipe from the sump pump is o.k..

Control unit and electrical work:
Control unit: o.k., no signs of corrossion, all SPS- modules work properly, no signs of failure. Compressor is running.

In general:
The consumption of treated water is rather high, compared to buildings in Germany,(40 liters/p/d/dk to 25-30liters/p/d/d) which may be because of the 9 liter cisterns used, we would advice to replace them with 6 liter cisterns when exchanging cisterns.

Protokoll by

Ralf Grehl