A novel set up composed of an anaerobic biofilm reactor followed by ozonation was used for treatment of artificial and real textile effluents containing azo dyes. The biological treatment efficiently removed chemical oxygen demand and color. Ozonation further reduced the organic content of the effluents and was very important for the degradation of aromatic compounds, as shown by the reduction of UV absorbance. The acute toxicity toward Vibrio fischeri and the shrimp Artemia salina increased after the biological treatment. No toxicity was detected after ozonation with the exception of the synthetic effluent containing the highest concentration, 1 g/l, of the azo dye Remazol Red. Both untreated and biologically treated textile effluents were found to have mutagenic effects. The mutagenicity increased even further after 1 min of ozonation. No mutagenicity was however detected in the effluents subjected to longer exposure to ozone.

The results of this study suggest that the use of ozonation as short post-treatment after a biological process can be beneficial for the degradation of recalcitrant compounds and the removal of toxicity of textile wastewater. However, monitoring of toxicity and especially mutagenicity is crucial and should always be used to assess the success of a treatment strategy.

Many commercial dye preparations are cocktails of active dyes and various by-products that are recalcitrant to biological degradation and end up in significant amounts in the effluent after the dyeing process. Conventional wastewater treatment processes are not able to degrade such compounds and detoxify the effluent, thus alternative treatments should be developed.

In our work we suggest to use photo-Fenton oxidation as post-treatment after an anaerobic biofilm process, in a way to minimize the reagents needed. This process was used for treatment of synthetic textile wastewater containing the commercial azo dyestuff Remazol Red, starch and sodium chloride. The treated textile effluent had COD lower than 18 mg/l even when using initial Fenton reagents concentration as low as 1 mM ferrous ions and 10 mM hydrogen peroxide. The acute toxicity was higher in the biologically treated than in the untreated effluent. Photo-Fenton oxidation successfully reduced the toxicity and the final effluent was non-toxic to Artemia salina and Microtox, with the exception of the effluent containing high concentration of sodium chloride, which was moderately toxic to Microtox. For the first time the presence of algae was detected in a reactor treating textile wastewater using denaturing gradient gel electrophoresis (DGGE); bacteria and fungi were also abundant.

The results of this study suggest that using advanced oxidation after biological treatment is an effective way to degrade the organic compounds and remove toxicity from textile effluents.

In the present study, two combinations of filter materials in filter/columns were examined for removal of total organic carbon (TOC) and polyphenols (PP) found in storm water runoff from wood storage areas in a wooden floor industry. One filter/column was packed with peat mixed with carbon-containing fly ash, while another filter/column contained only peat (without ash). The mixture of peat and ash has shown faster and higher removal capacity for TOC and faster removal with the same final removal capacity for PP (in grams of pollutant per kg of sorbent) at the saturation point. The superiority observed for the peat and ash filter is presumably due to the unique characteristics of peat and ash, which enhanced the treatment efficiency when used together in a mixture. Based on the observed results, filters formed by peat and carbon-containing ashes proved to be a potentially low-cost option for the treatment of storm water generated at storage areas of wood materials such as logs, sawdust and wood chips.

According to the results of the research performed in the different modern research laboratories the remnants of drugs and their derivatives are found in surface waters in France, USA, UK, Germany, Denmark and Sweden. These substances also can be found in sewage sludge, river and ocean sediments and in the municipal landfills filtrates. Some species have been found even in drinking water and ice, grou nd and ocean waters. Many studies confirmed the data of the annual drug releasing into the environment, which counts several hundred of kilograms. Thus, the investigations of negative impact of pharmaceutical substances and their derivatives on aquatic organisms have been performed  during more  than 20 years and showed an extremely negative presence of any drugs in the waters. Now, they are still  considering  as  emerging organic contaminants in the different type of waters. The main sources of water pollution by pharmaceuticals and their derivatives are wastewater from hospitals, clinics, pharmaceutical industries and domestic sewage as well. However, the main percentage of pharmaceuticals dumped into wastewaters is coming from the hospitals. This is typical for large cities, where is situated a great n um ber of hospitals and health care institutions. In the opinion of one study hospital wastewaters have been found in a 15 times higher potential ecotoxicity than the general urban have. The negative effect of pharmaceuticals influence into environment can be decrease due to application of different kinds of additional wastewater treatment as Advanced Oxidation Processes (AOPs). The main approaches of hospitals wastewater treatment in Ukraine and Sweden by implementation of AOPs method were considered in this study. The main data of this research will be presented. 

In this study, leachates resulting from leaching tests carried out with sawdust from five tree species were investigated. The studied species were: Pedunculate oak (Quercus robur), Scots pine (Pinus sylvestris), European larch (Larix decidua), Norway spruce (Picea abies) and European beech (Fagus sylvatica). The analyses included chemical parameters such as pH, TOC and phenolic compounds (reported as total poly-phenols) and acute toxicity on two different organisms, the crustacean Artemia salina and the bacteria Vibro fischeri (Microtox^®). There are very high amounts of different phenolic compounds in the leachate, and large differences between tree species. The leachates produced by sawdust and bark of different tree species presented great variation regarding acute toxicity. V. fischeri was more sensitive than A. salina and leachates from pine sawdust and pine bark produced the highest toxicity response from V. fischeri. This study indicates that bark is one component of the tree anatomy that needs to be handled as a potential hazardous material to the aquatic environment. The large variation in toxicity presented by different tree species need to be taken into account when assessing the impacts to surrounding watercourses and constructing wastewater treatment facilities for the wood-based industry such as irrigation water, stormwater runoff from storage areas.

This paper presents an evaluation of the suitability of a mixed absorbent based on peat and carbon-containing ash for treatment of wastewaters, such as wastewater from professional car washes, landfill leachate and stormwater. This mixture is very attractive, since it is a low-cost material which has a capability to simultaneously remove inorganic as well as organic pollutants. Since any filter material eventually needs to be replaced either due to saturation of pollutants or reduced infiltration capacity, it is important that the residual can be handled at low cost and that the environment will be not impaired. The tested mixture, used in filter beds, showed low leaching values and high simultaneous removal efficiency of metals as Cu, Cd and Pb, non-polar organic compounds such as PCBs. Polar organic compounds as phenols were also efficiently removed by microbial and/or chemical degradation in the studied treatment plants with the filter bed acted as a biofilter. Filter material used for three years in a full-scale plant for leachate treatment and four years in treatment plants for wastewater from car washes, had sufficiently high energy content indicating that energy recovery is a good alternative for handling after its usage. Results show that the presented filter material is excellent for both small scale applications (e.g. treatment systems for car wash wastewater with capacity between 250 - 3000 m³ per year) as well as large-scale applications (e.g. filter systems for landfill leachates with capacity above 30,000 m³ per year).

Landfill leachate contains a complex mixture of inorganic and organic pollutants, which need to be removed before they pollute the environment. Different filter media (peat mixed with either carbon-containing ash, polyurethane waste, or wood pellets) were investigated with respect to their possibility to simultaneously and at low initial concentrations remove metals, polar and non-polar organic compounds. The mixture of peat and carbon-containing ash was found to be the best medium. Reduction in leachate of phenolic substances was 96%, of PBDEs was over 98%, of DOC 40% and of important metals as Cu, Pb and Sn 60%, 90% and 93%, respectively.

Sludge from gullies, on two types of streets with different traffic intensity, was investigated using two recommended EU methods for leachability testing of waste: a two-stage batch test and an up-flow percolation test. The main purpose of this investigation was to gain more knowledge about these leaching test methods to be able to make future decisions on the general applicability of the proposed tests. A number of parameters were determined in the sludge as well as in the eluates obtained from the two leaching tests. These include pH, conductivity, dissolved organic carbon and inorganic ions as chloride ions. A number of metals as Cd, Cr, Cu, Hg, Ni and Zn, were determined by inductive coupled plasma-mass spectrometry and organic compounds were screened by high performance liquid chromatography-diode array UV detection and gas chromatography-mass spectrometry. It was found that the concentrations of metals and organic compounds in the sludge were several orders of magnitudes higher than the actual eluate concentrations. For all metals the concentrations were well below the proposed limit values for non-hazardous waste included in the Council decision document 2003/33/EC. Generally, concentrations obtained in batch test were equal or higher than from percolation tests. The repeatability of the percolation and the batch test were in average 28 and 17%, respectively.