Michal Marton's research while affiliated with Slovak University of Technology in Bratislava and other places

Many types of pharmaceutical substances have been detected with significant concentrations through various advanced instrumental techniques in surface water, ground water, partially treated water (with concentration typically less than 0,1 ug/L), drinking water (concentration bellow 0,05 ug/L) domestic wastewater, municipal wastewater and industrial effluents (concentration approximately 1 ug/L). Pharmaceutical compounds are found at much lower concentrations in drinking water sources then the normally prescribed doses, but there is concern that chronic exposure to numerous compounds could cause serious health problems and that compounds can act synergistically to cause adverse health effects. The effectiveness of removal the specific pharmaceuticals (paracetamol, carbamazepine, metronidazole and caffeine) from drinking water with adsorption using two types of granular activated carbon (Filtrasorb 400 and WG12) was monitored. Paracetamol is a medication used to treat fever and mild to moderate pain. Paracetamol significantly relieves pain in acute migraine and headache. Carbamazepine is an anticonvulsant medication used primarily in the treatment of epilepsy and neuropathic pain. It is used in schizophrenia along with other medications and as a second-line agent in bipolar disorder. Metronidazole is an antibiotic and antiprotozoal medication. It is used either alone or with other antibiotics to treat inflammatory disease. Caffeine is a central nervous system (CNS) stimulant of the methylxanthine class. It is the world’s most widely consumed psychoactive drug. The concentrations of caffeine in surface waters were detected in the range 0.1 - 6.9 μg/L. The experiments were performed in laboratory conditions with varying values of pH (7,8 or 6,5), stable temperature, and dose of adsorbent. The experiments were performed in the glass bottles with the volume of 400 mL stock model water (drinking water spiked with pharmaceutical standard) with concentration approximately 0.05 μg/L. On the analytical scales weighed out 400 mg GAC was used and then it was added to the bottles. Subsequently these bottles were regularly stirred at 400 rpm. Samples were taken at 30, 60, 120 and 240 minutes, after which they were analyzed. Analyses of target pharmaceutical were performed in laboratories of ALS Czech Republic in Prague. LC-MS methodology (method was validated according to ISO 17025 system) was used to determine pharmaceuticals in water samples. The adsorption efficiency of pharmaceutical removal and the adsorption capacity of granular activated carbon depends on the time of contact of water with the material. Adsorption efficiency for two types of granular activated carbon varies from 13 to more than 90%.

Pesticides are intensively used for the protection of field crops, orchards and vineyards, but they are also used in the removal of undesirable stands on non-agricultural land (railway embankments, playgrounds, handling areas, etc.), in water management (in coastal management, destruction of growths in irrigation canals), in forestry, etc. Regular application of pesticides increases their content in the aquatic environment and agricultural products. Their occurrence in water is relatively common and it follows that these substances are used in large quantities. Residues of these substances can persist in soils for 2 to 12 weeks. Due to their good solubility in water, they are easily transported from the soil to aquifers. Several methods can be used to remove pesticides from water, e.g., coagulation, filtration, precipitation, ozonation, adsorption, ion exchange, nanofiltration, reverse osmosis and advanced oxidation processes. Their effectiveness varies considerably and depends mainly on the chemical nature of the pesticide being removed. This article studies adsorption on two granular activated carbons Filtrasorb 400 and Norit 1240. Mixture of the pesticide standards (acetochlor, alachlor, dimethachlor, propachlor, metazachlor and metolachlor) was added to drinking water with concentration of approximately 1 µg/L. The experiments were performed in the glass bottles with the volume of 200 mL of water. The granular activated carbons (200 mg) were added to the bottles. Subsequently these bottles were regularly stirred, and the samples were taken out at times 0, 30, 60, 90, 120, 180, 240 and 360 minutes. Samples were taken by pipette into the 40 ml glass vials with added thiosulphate for preservation. Analyses of target pesticides were performed in laboratories of ALS Czech Republic in Prague. LC-MS using the internal standard method was used to determine chlorinated pesticides in water samples. The adsorption efficiency of pesticides removal and the adsorption capacity of granular activated carbon depends on the time of contact of water with the material. The results showed that the efficiency of selected pesticides removal and adsorption capacity for two granular activated carbons used varied. Filtrasorb F400 proved to be a better sorption material than Norit 1240. The efficiency of this material ranged from 18 to 60%, while the efficiency of Norit 1240 was significantly lower. Adsorption capacity of activated carbons for selected pesticides and reaction kinetics of 0th, 1st, 2nd and 3rd order was also studied.

Pesticides as one of the micro-pollutants present a great problem and threat to the environment and human health. They can infiltrate the sources of drinking water by application on the agricultural fields. This article is focused on Atrazine, Terbuthylazine and their metabolites. It is their complex structure that makes them hard to degrade naturally and, thus, water needs to be treated before safe using. Therefore, this article studies adsorption on the two granular activated carbons Filtrasorb 400 and Norit 1240 W. For the determination of the concentration liquid chromatography was used. In this article it is presented that Filtrasorb 400 efficiency (26–40% and 33–45% for atrazine and terbuthylazine respectively) is better than the efficiency of Norit 1240 W (9–27% and 10–24% for atrazine and terbuthylazine respectively).

The general characteristics of triazine herbicides and their negative effect on environments and human health are described in this article. Triazine herbicides currently account for more than half of all pesticide formulations. They are intensively used for the protection of field crops, orchards and vineyards, but they are also used in the removal of undesirable stands on non-agricultural land (railway embankments, playgrounds, handling areas, etc.), in water management (in coastal management, destruction of growths in irrigation canals), in forestry, etc. Regular application of herbicides increases their content in the aquatic environment and agricultural products. Their occurrence in water is relatively common and it follows that these substances are used in large quantities. Residues of these substances can persist in soils for 1 to 2 years. Due to their good solubility in water, they are easily transported from the soil to aquifers. Several methods can be used to remove pesticides from water, e.g. coagulation, filtration, precipitation, ozonation, adsorption, ion exchange, nanofiltration, reverse osmosis and advanced oxidation processes. Their effectiveness varies considerably and depends mainly on the chemical nature of the pesticide being removed. This article studies adsorption on the two granular activated carbons Filtrasorb 400 and Norit 1240 W. Model solution of the pesticides, with concentration of approximately 1 µg/L, was prepared by mixing 50 mL of the pesticide’s standards with approximately 5 L of drinking water. The pH of drinking water was neutral, and this solution was then properly mixed and was used in the experiments. The experiments were performed in the glass bottles with the volume of 200 mL pesticide solution. On the analytical scales weighed out 200 mg granular activated carbon was used and then it was added to the bottles. Subsequently these bottles were regularly stirred, and the samples were taken out at times 0, 30, 60, 90, 120, 180, 240 and 360 minutes. Samples were taken by pipette into the 40 ml glass vials with added thiosulfate for preservation. After the experiments, these vials were sent to the analytical laboratory, which performed the analysis of the concentration of pesticides. The performed analytical methods were consistent with US EPA 535 and US EPA 1694. Concentration was determined by liquid chromatography using an internal standard method. The triazine herbicides detection analysis results after adsorption process in drinking water spiked with standard of pesticides shows, that the efficiency of selected triazines removal and adsorption capacity for two granular activated carbons used varied. Filtrasorb F400 proved to be a better sorption material than Norit 1240. The efficiency of this material ranged from 18 to 60%, while the efficiency of Norit 1240 was significantly lower.

Ultrafiltration (UF) is a membrane separation process by which the particles of mechanical nature are removed from the water. Thanks to the pore diameter that are the order of tenths nm and the material, constructional and chemical properties of UF membranes, this technology represents the final solution for a secured protection against the turbidity that is caused by content of non-soluble and colloid particles of organic and inorganic origin, bacteria and the majority of viruses. Ultrafiltration was investigated within the pilot-plant tests at the WTP Jasná during the treatment of surface water originating from the water source Zadná voda. Water treatment is in this locality focused on turbidity that is caused by storm rainfalls and snow thawing. Fully automated ultrafiltration equipment with the membrane modul UA-640 (Microdyn-Nadir) was used. On the base of filtration cycles, the effectiveness of membraned technology was evaluated. Water was supplied to the UF-device by the pump, so the UF-flow rate was invariably maintained at the 600 L/h Period of filtration cycle was 30 minutes. Following the end of the cycle, washing of membrane by using the back-flushing by water and air was applied. Filtered water accumulated in the tank was used for back-flushing while the air was supplied by the air-pump connected to the device. Any way of washing of the membrane did last for 30 seconds. On the base of filtration cycles, the effectiveness of membraned technology was evaluated. Turbidity removal is the major issue at the WTP Jasná. Limit for turbidity 5 NTU is set by Decree No. 247/2007 Col. Measuring data provided that the turbidity level of water treated by using the ultrafiltration device are compliant with the legal limit for drinking water. By using the ultrafiltration, the decrease by 76,1% has been reached in the first experiment (average turbidity in raw water 1,55 NTU). The efficiency of turbidity removal was 95,2% that was reached by ultrafiltration of water with a higher level of turbidity (average turbidity in raw water 8 NTU). High effectiveness of ultrafiltration was reached also with the water with the turbidity 37 NTU. In all of the three experiments, the turbidity of treated water ranged between 0,37 - 0,38 NTU.

Pesticides, as one of the main monitored micropollutants these days, are monitored and determined even in the drinking water, because of their toxic effect on the living organisms. Presence of these pesticides in the drinking water is undesirable and, therefore, they need to be removed. Chloroacetanilides belong to the group of herbicides, which are commonly used in agriculture. Their complex structure prevents common biological degradation, so more complex processes are needed. One of the most efficient process for their removal is adsorption on activated carbon. In this article adsorption of certain chloroacetanilides from water for two different types of granular activated carbon is presented. Matrix used for dilution of pesticides was drinking water and the efficiency of the removal of pesticides ranged from 5 to 60 % for the specific sorption materials and pesticides. This research has shown that adsorption material Filtrasorb 400 is far more efficient than Norit 1240.

Ultrafiltration was investigated within the pilot-plant tests at the Rozgrund water treatment plant during the treatment of surface water originating from the Rozgrund reservoir. Fully automated ultrafiltration equipment with the membrane module UA-640 (Microdyn-Nadir) was used. On the base of filtration cycles, the effectiveness of membraned technology was evaluated. By the application of membrane technology used, the required quality of treated water has been achieved.

The general characteristics of humic substances (HS) and their negative effect on water quality and its treatment are described. The paper presents the results from the removal of humic substances from the Hriňová (Slovakia) water reservoir using 1) granular activated carbon (GAC) from two producers (Chemviron, Cabot) at three different pH levels, 2) by coagulation with two coagulants (aluminum sulfate and ferric sulfate), and 3) by an advanced oxidation process using UV radiation with the addition of the oxidizing agent hydrogen peroxide. The effectiveness of the removal of humic substances (expressed by the TOC parameter) from water with adsorption by GAC, depending on the contact time with the water, ranged from 14 % for one hour to 50% for eight hours of contact time. The calculated GAC adsorption capacity of the humic substances ranged from 0.05 mg/g for one hour to 0.19 mg/g for eight hours of contact time. The pH of the water had no significant effect on the level of efficiency. A high level of efficiency (50%) and the lowest value of TOC are obtained at a pH of 6.5. The humic substances remain in the water though the optimal dose of the coagulant was used. The ferric sulfate coagulant is more suitable for removing of humic substances from water as aluminum sulfate. A dose of 16 mg/L of 1% solution Fe 2 (SO 4 ) 3 , which is the equivalent of 4.47 mg/L Fe3+, is sufficient for the reduction of humic substances below 1 mg/L. The effectiveness of the removal of humic substances with coagulation using iron sulfate was 83% for a parameter of HS and 50% for TOC or COD Mn . The iron sulfate has the influence on a reduction in pH of water, therefore pH of water should be adjusted after coagulation. A laboratory study of removal of humic acids from surface water by UV radiation and addition of hydrogen peroxide in order to increase the oxidation of organics are presented. The results showed that UV radiation and addition of H 2 O 2 during the first few minutes of irradiation increases the concentration of the humic substances, COD Mn and TOC in water. After 3 minutes of exposure to UV radiation, these values were reduced to baseline, and in the next irradiation phase the values of the monitored parameters decreased. The highly reactive OH radicals with a high oxidation potential oxidize humic substances to various intermediates (a lower molecular weight substances). After 20 minutes of irradiation, a decrease in the parameters of approx. 39% for TOC, 62% for COD Mn and 37% for humic substances was observed.