Human waste being collected in Kiel |
The waste was collected in
buckets and sold to gardeners and farmers to use as fertiliser. This
took place in Lübeck up until 1952. |
 |
William
Lindley
(7 September 1808 - 22 May 1900) was a famous British engineer who
together with his sons designed water and sewerage systems for
over 30
cities across Europe, including Stralsund. In 1863 he began work on the
sewerage system of Frankfurt am Main. Within 20 years the death rate
from typhoid fell from 80 to
10 per 100,000 inhabitants. He used subsidence tanks for
clarification and introduced sand-filtration, which was only adopted
after the cholera epidemic of 1892- 1893. Lindley's designs were in
demand across Germany and elsewhere, including St. Petersburg,
Budapest and Moscow. In 1876 the Australian city of Sydney even asked
him to design a sewer system for them, but he turned them down as he
had just been commissioned by Warsaw. |
The old wooden pipes are being
replaced with new ones. Image taken in the center of Stralsund.
Section of wooden pipe
During
the period since the introduction of sewers in Stralsund in 1859 up
until effective
cleaning measures were taken in 1995 - a time-span of more
than 100 years - human and industrial waste has been released
straight
into the Baltic Sea. This has been, and in some places still are the
way waste is being dealt with for cities around the sea. Being an almost
enclosed and somewhat shallow body
of water, the Baltic Sea is very sensitive to human intervention. A
series of correlating events lead to a dramatic worsening of the
maritime environment, the extent to which scientists only became aware
of in the early 60'ies.
Field
Trip to the Stralsund waste water plant
Solid objects such as CDs and other large items are the first to be
removed in the cleaning process. |
This is followed by a process of mechanical cleaning where
the sediments settle over time. |
In the biological cleaning process air is pumped through the water,
allowing perfect conditions for the growth of anaerobe
bacteria and algae that further cleans the water. |
By the final stage the water is 98% clean. It is then pumped into the
Strelasund. |
The by-products from the water
cleaning process are stored in large containers, where they create the
methane gas that powers the entire sewerage plant.
|