After a tiring travel yesterday, we visited the waste water treatment plant (ARA) of Basel Landschaft.
The waste water plant had a purpose of treating waste water from homes, streets and industry and also cleaning the part of the Rhine within the city.
Mr Pascal Hubmann was the gentle fellow who took time to show us around the facility.
First to know were the various administrative and Laboratory departments at the facility. The facility was built around 1977 and was re-facilitated around 2007. There was more changes at the station i noticed, compared to what i saw and experienced two years ago with Mr. Petitjean.
The outlets of the sewage plant after waste water treatment includes,
- Clear water to the Rhine
- Bio-gas for water heating and electricity generation
- Dehydrated Slug to Landfill
- Sand to landfills
Technical Experience
The general process of the plant can be divided in two;
Mechanical and Biological Processes
Mechanical and Biological Processes
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| Screening Machine |
- Mechanical Treatment
The waste water intake part of the plant has an open air pump system taking 500l/sec of water to the sieving station. The open case pump is very important to prevent clogging due to large materials like wood and branches that finds their way to the station. This is also important for aeration of the intake water.
The waste water at the screening level is a delicate act, that has now been complicated with morning screening machines with 6mm and 20mm screens. This machine also have objects sensors, that activates the appropriate screen size via the presence and size of an object.
A sedimentation chamber settles and absorbs sand from the waste water after screening.
A dehydration chamber washes and dries the sand which is transported to landfills.
A 4mm screening system then screens the water before it enters the pre-clearifier.
2. Biological Treatment
A Batch biological process is used at this stage.Sequential batch reactors are a type of activated sludge process for the treatment of wastewater. SBR reactors treat wastewater such as sewage or mechanical biological treatment facilities in batches. Oxygen is bubbled through the mixture of wastewater and activated sludge to reduce the organic matter.
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| Reactors |
There are 5 reactors of 8400 cubic meters volume each. Each reactor has four stirrers and is aerated at 100%. Also 1200 Descender or Prefurated rubbers discs pumped water into the reactor.
Also present in the reactors were Oxygen (O2) , Ammonia and nitrogen probes.
The treated effluent is taken and suitable for discharge to the Rhine.Some of the settled slug are kept and used during another cycle of the process. about 70% of the slug is pumped into a slug digest-or.
After 30 days, the digest-or gives out slug matter and Biogas as its output.
The biogas is used in a gas fueled generator which powers the plant and also used to heat water for the FCB football pitch and also some general swimming pools and houses during the winter.
After 30 days, the digest-or gives out slug matter and Biogas as its output.
The biogas is used in a gas fueled generator which powers the plant and also used to heat water for the FCB football pitch and also some general swimming pools and houses during the winter.
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| Cafe Discussion |
One-third of the the bio-gas is used for electricity generation and 2/3s of it is used to boil hot water.
The slug matter is pumped into a Centrifuge machine, that turns at 4000 turns/min. Which dehydrates and increases amount of solid matter the slug from 4% to 30%.
The slug matter is pumped into a Centrifuge machine, that turns at 4000 turns/min. Which dehydrates and increases amount of solid matter the slug from 4% to 30%.
At this section is a moisture Analyser which determine which aims at measuring a low moisture concentration in the slug matter. This stage is very important before incineration process.
The aches after incineration contains more phosphorous and because current technology cannot really extract this from the aches, the ashes are currently stored at landfill sites to be mined in the future when such a technology is available.
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| Flight Simulation |
Other Notable observations was the solar power plants at the station.
And the number of Staff at the facility.
Promising and interesting events also include when we had the opportunity to meet the Director of the station who shared his interest in having for internship training. Mrs. Petitjean was in full support of this idea and her role in this can never be over look nor forgotten. We hope for further activities to be done on this idea.
After the excursion, Mr. Hubsmann pointed out some facts comparison of Centralized and Decentralized waste water treatment system. Most Ghanaian use decentralized system of waste treatment. And recently, most people are having the idea of having a centralized system for towns and even houses in the new sites. But he explains that, centralized system is more costly, and Switzerland still uses thata because the pipe lines have already been layed and they cannot reverse either wise.
Afterwards, we visited Aunt Margrethe at Frenkendorf. Mrs. Margrethe is a cousin of Mrs. Ruth Petitjean. And she requested to meat us. Here husband also knew how interested we will be to use and practice with his Flight Simulator.
Even though Mr Kurt wasn't around - and i would have loved to meet him again- a friend of his made our day and exciting one.
Well its was a very nice dinner, a good flight and i surely couldn't resist to touch that grand piano.
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