2001-4

Sewer systems influence the local urban hydrology rhrough infiltration ofgroundwarer. Experiences indicate a limited use of traditional countermeasures for limiting the inflow/infiltration. Implementing alternative schemes introduces on the other hand many new technical issues. The answers to these demand a thorough geohydrological understanding of the catchment. The ability to describe this complex interaction and to […]

A pilot plant study with biological treatment has been carried out at Mörrum Bruk. The pilot plant was built as the future external treatment plant, a multistage biology or a so-called Multibio. The total retention time in the biological stages was slightly more than 7 hours. The volume load was about 5,5 kg COD/m3 d. […]

The occurrence of Giardia and Cryptosporidium in Swedish Wastewater treatment Plants (WWTP) has previously not been investigated. Giardia cysts were present in the untreated wastewater at every sampling occasion at all test sites in densities between 24—160 cysts/L, but only twice in the treated wastewater and in lower densities. Cryptosporidium oocysts were detected in 67 […]

Waste deposits generate polluted water, leachate, which contains metal ions. Leachate is often led to waste water purifying plants. The metals sediment and end up in the digested sludge, which often is taken back to the waste deposit. This results in a negative eco-cycle. Metal ions in solution can be captured by ion-exchangers, but commercially […]

A Danish and a Swedish study of nitrification inhibition are compared. A considerably larger percentage of’ the Danish treatment plants received wastewaters strongly inhibitory to nitrification compared to the Swedish treatment plants. More than 20 % inhibition in a 50% dilution of the samples was noted for about a fourth of the investigated Danish wastewaters. […]