Global NEST International Conference on Environmental Science & Technology
Ozonation was studied as a pretreatment method for a waste biological sludge, contaminated with l... more Ozonation was studied as a pretreatment method for a waste biological sludge, contaminated with large amounts of globally used antibiotics; tiamulin, levofloxacin and amoxicillin. At the concentrations of over 100 mg L-1, these antibiotics were found to inhibit biogas production (up to 50%), which means, that the molecules would pass the anaerobic digestion system unchanged. Ozonation of sludge, contaminated with antibiotics, not only removes inhibitory effects but also improves overall biogas production for 10% or even more, depending on the dose of the oxidant.
The procedure of the utilization of dynamic simulation programs for design and upgrading of biolo... more The procedure of the utilization of dynamic simulation programs for design and upgrading of biological processes of nitrogen removal is presented. An upgrading of nitrification reactor to predenitrification system is illustrated. Design calculations were performed according to steady-state design practice. An optimization procedure for calculation of volume of denitrification reactor was developed. Minimizing of differences between required and calculated values of denitrified nitrogen is the merit of the applied method. Dynamic simulations were used for optimization of the dimensions of nitrification and denitrification reactors with regard to effluent standard values and fluctuations of wastewater flow and composition. A method for evaluation of dynamic simulation of results with respect to dynamic nature of wastewater effluent standards is suggested.
Chemical and Biochemical Engineering Quarterly, 2017
The results of the study of removal of nonylphenol, octylphenol and their ethoxylates from real i... more The results of the study of removal of nonylphenol, octylphenol and their ethoxylates from real industrial and municipal wastewater are presented. Industrial wastewater was pre-treated by coagulation with FeCl 3 and adsorption on zeolite, before discharging into municipal sewer system. Their removal efficiencies in primary sedimentation tank of municipal WWTP were very low. From the practical point of view, the highest and the most significant removal efficiencies within the whole WWTP were observed for nonylphenol and nonylphenol ethoxylates. Dominancy of abiotic mechanisms of alkylphenols removal follows from adsorption measurements. Activated sludge cultivated in lab-scale extended aeration tank accounted for relatively high adsorption affinity to these substances. Activated sludge sampled from municipal wastewater treatment plant (MWWTP) receiving industrial wastewater containing alkylphenols accounted for very low adsorption affinity to these pollutants. Significantly higher removal efficiency of octylphenol ethoxylates was observed with the O 3 /granular active carbon (GAC) process compared to the ozonation process alone. Lower toxicity impact of intermediates and products of ozonation treatment on Vibrio fischeri was measured in comparison to the O 3 /GAC process. Actually, the municipal WWTP effluent discharge concentration values complies with EQS values, including nonylphenols.
The aim of our research was to evaluate treatment efficiency of Fenton’s process and ozonation fo... more The aim of our research was to evaluate treatment efficiency of Fenton’s process and ozonation for the treatment of two landfill leachates (fresh and mature), both resulting from municipal waste disposal. Both samples had high organic load (COD of the fresh and mature landfill leachate were 2700 and 490 mg·L
Polychlorinated biphenyls (PCBs) produced in Slovakia as a commercial mixture Delor 103 cause the... more Polychlorinated biphenyls (PCBs) produced in Slovakia as a commercial mixture Delor 103 cause the main contamination of sediment, water and fish in the eastern part of Slovakia. Delor 103 is a mixture of 40% PCB congeners, nine of them: PCB 8 (2,4'-dichlorobiphenyl), PCB 28 (2,4,4'-trichlorobiphenyl), PCB 52 (2,2',5,5'-tetrachlorobiphenyl), PCB 101 (2,2',4,5,5'-pentachlorobiphenyl), PCB 118 (2,3',4,4',5-pentachlorobiphenyl), PCB 138 (2,2',3,4,4',5'-hexachlorobiphenyl), PCB 153 (2,2',4,4',5,5'-hexachlorobiphenyl), PCB 180 (2,2',3,4,4',5,5'-heptachlorobiphenyl), and PCB 203 (2,2',3,4,4',5,5',6-octachlorobiphenyl), were monitored for their removal by ozonation and biodegradation using Achromobacter xylosoxidans. Ozonation improved the removal of PCB 52, 118, 153, 138, 180, and 203 using biological method with A. xylosoxidans. Degradation of 55% of the total amount of nine selected PCB congeners was achieved by the biological method with A. xylosoxidans, while 86% of the total amount of the nine selected PCB congeners were removed by the ozonation method; using a combination of biological and chemical methods, ozonation and A. xylosoxidans, showed a 94% removal efficiency of the selected PCB congeners present in mixture Delor 103.
Chlorine dioxide (ClO 2 ) has been successfully used for taste and odor control, color reduction,... more Chlorine dioxide (ClO 2 ) has been successfully used for taste and odor control, color reduction, and oxidation of inorganics like iron, manganese or sulfur compounds. More recently, the interest has been growing in its use in a variety of applications as an alternative to or supplement of conventional chlorine disinfection. It has been used in conventional water treatment and as a disinfectant in water supply systems. An advantage of using chlorine dioxide is that it does not form halogenated by-products as it is the case with chlorine. Thus it is possible to produce safe, chemically disinfected water without using chlorine or expensive ozone.
The aim of our work was to evaluate the efficiency of oxidative processes for treatment of munici... more The aim of our work was to evaluate the efficiency of oxidative processes for treatment of municipal landfill leachates. Several oxidative treatment procedures were used for four selected landfill leachates, two of them obtained in municipal landfills in Slovakia (LL1, LL2), while two of them were originated from Slovenia (LL3, LL4). They all represent typical municipal landfill leachates of particular country, with high organic load and composition beyond effluent limits of particular country. The first two landfill leachates (LL1 and LL2) were also treated biologically to compare efficiency of biological treatment and ozonation. Both, raw and biologically treated leachates LL1 and LL2 were then used for ozonation experiments. Some ozonation experiments were also performed with addition of Fenton reagents. Increase in biotreatability of ozonated leachate LL1 was investigated using kinetic test with different types (adapted, non-adapted) activated sludge. Slovenian landfill leachate...
This study compares efficiency of Fenton's oxidation and ozonation of 17β-estradiol (E2) and ... more This study compares efficiency of Fenton's oxidation and ozonation of 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) as two possible processes for removal of estrogens from aqueous solutions. The effectiveness of Fenton's oxidative removal was studied at different ratios of reagents Fe2+:H2O2 (1:0.5; 1:10; 1:20; 1:33), where with some molar ratios up to 100% removal of E2 and EE2 was achieved in the first few minutes of reaction. The best molar ratio for E2 (17β-estradiol) removal was 1:33, while in the case of EE2 the most efficient one was 1:20 ratio. Ozonation was much faster, because complete removal of estrogens was achieved in 30 seconds (pH≈6), but the time of ozonation was extended up to 60 minutes trying to decompose formed by-products, expressing estrogenic activity, detected by YES (Yeast Estrogen Screening) assay. The obtained results showed that the removal efficiency of estrogens from waters should be assessed by a combination of chemical analyses and bioassay.
The objective of this investigation was determination of feasibility of ozonation for treatment o... more The objective of this investigation was determination of feasibility of ozonation for treatment of leachates from municipal landfill. Efficiency of ozonation was determined for two leachates, different in age, composition and toxicity. We have studied the impact of ozonation time on removal of organics. The efficiency of treatment was monitored by COD, BOD5 and DOC analyses, removal of nitrogen compounds, as well as changes in toxicity. Therefore, acute toxicity tests with luminiscent bacteria Vibrio fischeri, Daphnia magna and nitrifying organisms of activated sludge (ammonium oxidation) were performed prior and after ozonation experiments. It has been confirmed that longer time of ozonation does not bring significantly better results regarding treatment of young leachate (36% in 20 minutes, 42% in 120 minutes). Two steps kinetics observed resulted in minor detoxification regarding luminiscent bacteria and no changes in effects to daphnids. More effective was ozonation of the stabi...
Kinetics and efficiency of Fenton’s and ozonation processes for the pretreatment of two landfill ... more Kinetics and efficiency of Fenton’s and ozonation processes for the pretreatment of two landfill leachates (fresh and mature) resulting from municipal waste disposal were studied. Both samples presented high organic load, high toxicity and low biodegradability. These were the reasons why oxidative treatment was proposed. Fresh and mature leachate showed different behaviors in the oxidation experiments. The final extents of removal were attained in comparable time intervals in both oxidation systems. Maximal removal of organics by the Fenton’s oxidation reached more than 50 % according to COD. Zero or first order kinetics were found the best to describe the organic components (in terms of COD and DOC) removal by the Fenton’s oxidation for both landfill leachates. Higher reaction rate values of the Fenton’s oxidation were achieved with fresh leachate samples. The efficiency of initial organics removal with ozone was about 70 % for mature leachate, while in case of the fresh one only 4...
Mathematical and Computer Modelling of Dynamical Systems, Aug 9, 2010
Page 1. Modelling of an Intermittently Aerated Completely Mixed Activated Sludge Reactor JAè N DE... more Page 1. Modelling of an Intermittently Aerated Completely Mixed Activated Sludge Reactor JAè N DERCO*, ALEXANDER KOVAèCS, MILAN KRAèLIK AND SALIMA SHANSAB ABSTRACT Mathematical models for description ...
The influence of cyclohexanone on oxygen transfer rate from air to water was studied. Signifi-can... more The influence of cyclohexanone on oxygen transfer rate from air to water was studied. Signifi-cant changes of bubble size and distribution in a bioreactor were observed, particularly at higher cyclohexanone concentration values. The rate of water saturation with oxygen was markedly higher in fresh water in comparison to activated sludge suspension. Considerable change in the rate of oxygen saturation of water in the absence of sludge was observed already at cyclohexanone concentration 100 mg.l -1 . On the other hand, insignificant differences in the rate of oxygen saturation were measured in activated sludge suspension. The relationships between oxygen transfer coefficient values and cyclohexanone concentration for fresh water and sludge suspension were evaluated. These relationships enable to specify the description of oxygen transfer and oxygen balance in modelling of synthetic or real wastewater with cyclohexanone content as predominant organic substrate.
The possibilities of utilisation of ozone for removal of 2-mercaptobenzothiazole (MBT) from waste... more The possibilities of utilisation of ozone for removal of 2-mercaptobenzothiazole (MBT) from wastewater were studied in lab-scale. COD removal efficiency about 85 % was achieved after 6 hours of ozonation of the synthetic wastewater. The best fit of experimental COD data during ozonation was achieved with the zero order reaction kinetic model. Ozonation of MBT had positive influence on increase of biodegradability and respiration activity of activated sludge in the presence of wastewater after ozonation. The increase of BOD values and specific exogenous respiration rate with time of ozonation was observed within the performed measurements.
Possibilities for disposal of accidents caused by escape of oil products into environment were in... more Possibilities for disposal of accidents caused by escape of oil products into environment were investigated in lab-scale. The aim of experimental work was to evaluate the influence of selected degreaser on biodegradability of diesel-oil as well as to find out the most convenient dilution of the degreaser. Respirometric measurements were applied to evaluate biodegradability. The highest values of respiration rate were measured at 25 multiple dilution of degreaser with water and the ratios of the degreaser to motor-oil 0.25 to 2.0.
Mathematical and Computer Modelling of Dynamical Systems, 1999
Page 1. Modelling of an Intermittently Aerated Completely Mixed Activated Sludge Reactor JAè N DE... more Page 1. Modelling of an Intermittently Aerated Completely Mixed Activated Sludge Reactor JAè N DERCO*, ALEXANDER KOVAèCS, MILAN KRAèLIK AND SALIMA SHANSAB ABSTRACT Mathematical models for description ...
Global NEST International Conference on Environmental Science & Technology
Ozonation was studied as a pretreatment method for a waste biological sludge, contaminated with l... more Ozonation was studied as a pretreatment method for a waste biological sludge, contaminated with large amounts of globally used antibiotics; tiamulin, levofloxacin and amoxicillin. At the concentrations of over 100 mg L-1, these antibiotics were found to inhibit biogas production (up to 50%), which means, that the molecules would pass the anaerobic digestion system unchanged. Ozonation of sludge, contaminated with antibiotics, not only removes inhibitory effects but also improves overall biogas production for 10% or even more, depending on the dose of the oxidant.
The procedure of the utilization of dynamic simulation programs for design and upgrading of biolo... more The procedure of the utilization of dynamic simulation programs for design and upgrading of biological processes of nitrogen removal is presented. An upgrading of nitrification reactor to predenitrification system is illustrated. Design calculations were performed according to steady-state design practice. An optimization procedure for calculation of volume of denitrification reactor was developed. Minimizing of differences between required and calculated values of denitrified nitrogen is the merit of the applied method. Dynamic simulations were used for optimization of the dimensions of nitrification and denitrification reactors with regard to effluent standard values and fluctuations of wastewater flow and composition. A method for evaluation of dynamic simulation of results with respect to dynamic nature of wastewater effluent standards is suggested.
Chemical and Biochemical Engineering Quarterly, 2017
The results of the study of removal of nonylphenol, octylphenol and their ethoxylates from real i... more The results of the study of removal of nonylphenol, octylphenol and their ethoxylates from real industrial and municipal wastewater are presented. Industrial wastewater was pre-treated by coagulation with FeCl 3 and adsorption on zeolite, before discharging into municipal sewer system. Their removal efficiencies in primary sedimentation tank of municipal WWTP were very low. From the practical point of view, the highest and the most significant removal efficiencies within the whole WWTP were observed for nonylphenol and nonylphenol ethoxylates. Dominancy of abiotic mechanisms of alkylphenols removal follows from adsorption measurements. Activated sludge cultivated in lab-scale extended aeration tank accounted for relatively high adsorption affinity to these substances. Activated sludge sampled from municipal wastewater treatment plant (MWWTP) receiving industrial wastewater containing alkylphenols accounted for very low adsorption affinity to these pollutants. Significantly higher removal efficiency of octylphenol ethoxylates was observed with the O 3 /granular active carbon (GAC) process compared to the ozonation process alone. Lower toxicity impact of intermediates and products of ozonation treatment on Vibrio fischeri was measured in comparison to the O 3 /GAC process. Actually, the municipal WWTP effluent discharge concentration values complies with EQS values, including nonylphenols.
The aim of our research was to evaluate treatment efficiency of Fenton’s process and ozonation fo... more The aim of our research was to evaluate treatment efficiency of Fenton’s process and ozonation for the treatment of two landfill leachates (fresh and mature), both resulting from municipal waste disposal. Both samples had high organic load (COD of the fresh and mature landfill leachate were 2700 and 490 mg·L
Polychlorinated biphenyls (PCBs) produced in Slovakia as a commercial mixture Delor 103 cause the... more Polychlorinated biphenyls (PCBs) produced in Slovakia as a commercial mixture Delor 103 cause the main contamination of sediment, water and fish in the eastern part of Slovakia. Delor 103 is a mixture of 40% PCB congeners, nine of them: PCB 8 (2,4'-dichlorobiphenyl), PCB 28 (2,4,4'-trichlorobiphenyl), PCB 52 (2,2',5,5'-tetrachlorobiphenyl), PCB 101 (2,2',4,5,5'-pentachlorobiphenyl), PCB 118 (2,3',4,4',5-pentachlorobiphenyl), PCB 138 (2,2',3,4,4',5'-hexachlorobiphenyl), PCB 153 (2,2',4,4',5,5'-hexachlorobiphenyl), PCB 180 (2,2',3,4,4',5,5'-heptachlorobiphenyl), and PCB 203 (2,2',3,4,4',5,5',6-octachlorobiphenyl), were monitored for their removal by ozonation and biodegradation using Achromobacter xylosoxidans. Ozonation improved the removal of PCB 52, 118, 153, 138, 180, and 203 using biological method with A. xylosoxidans. Degradation of 55% of the total amount of nine selected PCB congeners was achieved by the biological method with A. xylosoxidans, while 86% of the total amount of the nine selected PCB congeners were removed by the ozonation method; using a combination of biological and chemical methods, ozonation and A. xylosoxidans, showed a 94% removal efficiency of the selected PCB congeners present in mixture Delor 103.
Chlorine dioxide (ClO 2 ) has been successfully used for taste and odor control, color reduction,... more Chlorine dioxide (ClO 2 ) has been successfully used for taste and odor control, color reduction, and oxidation of inorganics like iron, manganese or sulfur compounds. More recently, the interest has been growing in its use in a variety of applications as an alternative to or supplement of conventional chlorine disinfection. It has been used in conventional water treatment and as a disinfectant in water supply systems. An advantage of using chlorine dioxide is that it does not form halogenated by-products as it is the case with chlorine. Thus it is possible to produce safe, chemically disinfected water without using chlorine or expensive ozone.
The aim of our work was to evaluate the efficiency of oxidative processes for treatment of munici... more The aim of our work was to evaluate the efficiency of oxidative processes for treatment of municipal landfill leachates. Several oxidative treatment procedures were used for four selected landfill leachates, two of them obtained in municipal landfills in Slovakia (LL1, LL2), while two of them were originated from Slovenia (LL3, LL4). They all represent typical municipal landfill leachates of particular country, with high organic load and composition beyond effluent limits of particular country. The first two landfill leachates (LL1 and LL2) were also treated biologically to compare efficiency of biological treatment and ozonation. Both, raw and biologically treated leachates LL1 and LL2 were then used for ozonation experiments. Some ozonation experiments were also performed with addition of Fenton reagents. Increase in biotreatability of ozonated leachate LL1 was investigated using kinetic test with different types (adapted, non-adapted) activated sludge. Slovenian landfill leachate...
This study compares efficiency of Fenton's oxidation and ozonation of 17β-estradiol (E2) and ... more This study compares efficiency of Fenton's oxidation and ozonation of 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) as two possible processes for removal of estrogens from aqueous solutions. The effectiveness of Fenton's oxidative removal was studied at different ratios of reagents Fe2+:H2O2 (1:0.5; 1:10; 1:20; 1:33), where with some molar ratios up to 100% removal of E2 and EE2 was achieved in the first few minutes of reaction. The best molar ratio for E2 (17β-estradiol) removal was 1:33, while in the case of EE2 the most efficient one was 1:20 ratio. Ozonation was much faster, because complete removal of estrogens was achieved in 30 seconds (pH≈6), but the time of ozonation was extended up to 60 minutes trying to decompose formed by-products, expressing estrogenic activity, detected by YES (Yeast Estrogen Screening) assay. The obtained results showed that the removal efficiency of estrogens from waters should be assessed by a combination of chemical analyses and bioassay.
The objective of this investigation was determination of feasibility of ozonation for treatment o... more The objective of this investigation was determination of feasibility of ozonation for treatment of leachates from municipal landfill. Efficiency of ozonation was determined for two leachates, different in age, composition and toxicity. We have studied the impact of ozonation time on removal of organics. The efficiency of treatment was monitored by COD, BOD5 and DOC analyses, removal of nitrogen compounds, as well as changes in toxicity. Therefore, acute toxicity tests with luminiscent bacteria Vibrio fischeri, Daphnia magna and nitrifying organisms of activated sludge (ammonium oxidation) were performed prior and after ozonation experiments. It has been confirmed that longer time of ozonation does not bring significantly better results regarding treatment of young leachate (36% in 20 minutes, 42% in 120 minutes). Two steps kinetics observed resulted in minor detoxification regarding luminiscent bacteria and no changes in effects to daphnids. More effective was ozonation of the stabi...
Kinetics and efficiency of Fenton’s and ozonation processes for the pretreatment of two landfill ... more Kinetics and efficiency of Fenton’s and ozonation processes for the pretreatment of two landfill leachates (fresh and mature) resulting from municipal waste disposal were studied. Both samples presented high organic load, high toxicity and low biodegradability. These were the reasons why oxidative treatment was proposed. Fresh and mature leachate showed different behaviors in the oxidation experiments. The final extents of removal were attained in comparable time intervals in both oxidation systems. Maximal removal of organics by the Fenton’s oxidation reached more than 50 % according to COD. Zero or first order kinetics were found the best to describe the organic components (in terms of COD and DOC) removal by the Fenton’s oxidation for both landfill leachates. Higher reaction rate values of the Fenton’s oxidation were achieved with fresh leachate samples. The efficiency of initial organics removal with ozone was about 70 % for mature leachate, while in case of the fresh one only 4...
Mathematical and Computer Modelling of Dynamical Systems, Aug 9, 2010
Page 1. Modelling of an Intermittently Aerated Completely Mixed Activated Sludge Reactor JAè N DE... more Page 1. Modelling of an Intermittently Aerated Completely Mixed Activated Sludge Reactor JAè N DERCO*, ALEXANDER KOVAèCS, MILAN KRAèLIK AND SALIMA SHANSAB ABSTRACT Mathematical models for description ...
The influence of cyclohexanone on oxygen transfer rate from air to water was studied. Signifi-can... more The influence of cyclohexanone on oxygen transfer rate from air to water was studied. Signifi-cant changes of bubble size and distribution in a bioreactor were observed, particularly at higher cyclohexanone concentration values. The rate of water saturation with oxygen was markedly higher in fresh water in comparison to activated sludge suspension. Considerable change in the rate of oxygen saturation of water in the absence of sludge was observed already at cyclohexanone concentration 100 mg.l -1 . On the other hand, insignificant differences in the rate of oxygen saturation were measured in activated sludge suspension. The relationships between oxygen transfer coefficient values and cyclohexanone concentration for fresh water and sludge suspension were evaluated. These relationships enable to specify the description of oxygen transfer and oxygen balance in modelling of synthetic or real wastewater with cyclohexanone content as predominant organic substrate.
The possibilities of utilisation of ozone for removal of 2-mercaptobenzothiazole (MBT) from waste... more The possibilities of utilisation of ozone for removal of 2-mercaptobenzothiazole (MBT) from wastewater were studied in lab-scale. COD removal efficiency about 85 % was achieved after 6 hours of ozonation of the synthetic wastewater. The best fit of experimental COD data during ozonation was achieved with the zero order reaction kinetic model. Ozonation of MBT had positive influence on increase of biodegradability and respiration activity of activated sludge in the presence of wastewater after ozonation. The increase of BOD values and specific exogenous respiration rate with time of ozonation was observed within the performed measurements.
Possibilities for disposal of accidents caused by escape of oil products into environment were in... more Possibilities for disposal of accidents caused by escape of oil products into environment were investigated in lab-scale. The aim of experimental work was to evaluate the influence of selected degreaser on biodegradability of diesel-oil as well as to find out the most convenient dilution of the degreaser. Respirometric measurements were applied to evaluate biodegradability. The highest values of respiration rate were measured at 25 multiple dilution of degreaser with water and the ratios of the degreaser to motor-oil 0.25 to 2.0.
Mathematical and Computer Modelling of Dynamical Systems, 1999
Page 1. Modelling of an Intermittently Aerated Completely Mixed Activated Sludge Reactor JAè N DE... more Page 1. Modelling of an Intermittently Aerated Completely Mixed Activated Sludge Reactor JAè N DERCO*, ALEXANDER KOVAèCS, MILAN KRAèLIK AND SALIMA SHANSAB ABSTRACT Mathematical models for description ...
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