Phytoplankton estimation and biomass determination are routine procedures in many lake monitoring i programmes, but there are often methodical difterences in the way the different investigators perform these analyses. We present here the results from a Danish inrercalibration on phytoplankton investigations in lakes. The aim was to assess the uncertainty in connection with phytoplankton investigations […]
Publiceringsdatum
Författare
JENS PEDERJENSEN, MÄRTIN S0NDERGAARD, GERTRUD CRONBERG, and J0RGEN KRISTIANSEN
Nyckelord (Keyword)
phytoplankton, intercalibrarion, lake monitoring, biomass, blue-green algae, ultrasound, sonication.
Nummer
2
Årgång
51
Utgåva
A constructed wetland (30 ha) for reduction ofphosphorus and nitrogen has been creaced in connecrion to the effluent from the sewage treatment plant in the town of Hässleholm, Scania, southern Sweden. The supply of phosphorus to the wetland is calculated to be reduced by 50 %. The main phosphorus-redudng process will be uptake by macrophytes […]
Publiceringsdatum
Författare
HELÉNE ANNADOTTER, PER-ÅKE NILSSON, BEJRON LUNDSTEDT och SVEN STRÖBÄCK
Nyckelord (Keyword)
phosphorus reduction, nitrogen reduction, wedand, sewage treatment
Nummer
2
Årgång
51
Utgåva
There is a great amount of chemicals in common use which are not adequately tested for their toxicity to aquatic animals. This is pardy due to the fact that tradiiional toxicity tests on animals are time consuming and expensive. Toxicity tests on higher animals are also erhically questionable and one can also quesdon the informative […]
Publiceringsdatum
Författare
BORIS ISOMAA och HENRIK LILIUS
Nummer
2
Årgång
51
Utgåva
This work is based on data collected in the Liming-mercury-cesium project, and is, as far as the authors are aware, the most extensive set of dara collected to evaluate the eutrophication effecrs associated with fish farms in Swedish lakes. The hypothesis to test is whether fish farms raise lake phosphorus concentrations and thereby the production. […]
Publiceringsdatum
Författare
LARS HÅKANSON, LENNART CARLSSON och TORBJÖRN JOHANSSON
Nyckelord (Keyword)
lakes, fish farms, eutrophicanon, mass-balances
Nummer
2
Årgång
51
Utgåva
The hypothesis tested in this work is that there is a significant direct uptake of phosphorus (from faeces from the culrivared fish and feed loss) from fish farms leading to increased growth ofwild fish. Direct uptake (DU) is defined as the phosphorus bound in wild fish. DU is associated with the growth ofall types ofwild […]
Publiceringsdatum
Författare
KRISTIAN BORUM, TORBJÖRN JOHANSSON och LARS HÅKANSON
Nyckelord (Keyword)
lakes, fish farms, eutrophicanon, wild fish, direct uptake, particle experiment
Nummer
2
Årgång
51
Utgåva
THE EFFECT OF A pH-ADJUSTMENT COMBINED WITH THERMAL PRE-TREATMENT ON THE DEWATERlNG OF SEWAGE SLUDGE
It is invesdgated whether heat-treatment combined with pH-adjustmenr improves the dewatering characteristics of sewage sludge. The treatment is done in order to secure hygienisated sludge by which the manuring and earth-improving effect of the sludge can be utilized in agriculture without any precautions in the case of a fullscale sewage plant. Furthermore fihrate from the […]
Publiceringsdatum
Författare
ROALD THOR J0RGENSEN, STIG RASMUSSEN and MOGENS HENZE
Nyckelord (Keyword)
activated sludge, heat-treatment, filtrate as carbon source
Nummer
2
Årgång
51
Utgåva
The copper corrosion in the distrubution net ofdrinking waters with high hardness and high alcalinity, i.e. an aggressive water, poses a problem in the sewage water treatments planrs due to a high content of copper in the sludge.Correct pH and carbondioxide content will reduce the aggressiveness of the water and heavily reduce the copper corrosion. […]
Publiceringsdatum
Författare
BENGT JONSSON
Nummer
2
Årgång
51
Utgåva