Some amounts of inert products are given into environment due to biological degradation of substrate in activated sludge system. The effluent of biological wastewater treatment consists of inert substrate in influent flow, soluble microbial products and non degradable or slowly degradable organic...

The wastewater of leather industry which is one of the most widespread industries having large amount of water consumption and very high pollution loads, may be characterized by several key parameters including toxic pollutants exhibiting toxicity. Therefore the effluent of leather tanning industry...

This paper presents a biological method for controlling odor problems caused by H2S originating from sewer networks under anaerobic conditions. The proposed method is based on the continuous addition of nitrate which oxidizes dissolved sulphide according to an autotrophic biological procedure and...

Atrazine, a chlorinated s-triazine group of herbicide is one of the most widely used pesticides in the World. Due to its extensive use, long half-life and various toxic properties, it has very high environmental significance. Up to 22 mg l-1 of atrazine was found in ground water whereas permissible...

The process of nitrification in wastewater treatment is widely accepted as a two-step process. In the first step the ammonia is oxidized to nitrite, a process considered to be carried out mainly by the Nitrosomonas sp., while in the second step the Nitrobacter sp. oxidizes the nitrite to nitrate...

The El Nino-Southern Oscillation is the dominant pattern of short-term climate variation, and is therefore of great importance in climate studies. Some recent studies showed the teleconnection between stream flow and the El-Nino Southern Oscillation (ENSO) of the equatorial Pacific Ocean. This paper...

This paper aims at a comparative evaluation of the total cost of urban sewage processing units for several treatment systems, appropriate mainly for small capacity plants. The studied systems are: Oxidation Ditch (O.D.), Trickling Filter (T.F.), Rotating Biological Contactor (R.B.C.), Compact...

It is well known that the studies that associate the climatic changes with the greenhouse effect, as a sequence of uninterruptedly ongoing figures in the concentration mainly of carbon dioxide, have been focused on the trends of the mean temperature. On the other hand the variability and the trends...

The methylation of mercury has been investigated and documented mainly in sediments, fish and microorganisms, while limited number of relevant studies is available for wastewater. The procedure of mercury methylation can occur via biological pathway (by microorganisms) and via chemical or...

A teleconnection pattern has been identified between Eastern Mediterranean and Northwestern Europe in the geopotential fields of the upper troposphere (hereafter will be referred to as EMP) during winter and it seems to play significant role in the large-scale atmospheric circulation over...