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The fast and complete removal of the anti-cancer drug cytarabine (CYT) from water was studied, for the first time, by the electro-Fenton process using a BDD anode and carbon felt cathode. A catalytic amount (10−4 M) of ferrous iron was initially added to the solution as catalyst and it was electrochemically regenerated in the process. Complete degradation of 0.1 mM (24.3 mg L−1) CYT was achieved quickly in 15 min at 300 mA constant current electrolysis by hydroxyl radicals (●OH) electrocatalytically generated in the system. Almost complete mineralization (91.14% TOC removal) of the solution was obtained after 4 h of treatment. The mineralization current efficiency (MCE) and energy consumption (EC) during the mineralization process were evaluated. The absolute (second order) rate constant for the hydroxylation reaction of CYT by hydroxyl radicals was assessed by applying the competition kinetics method and found to be 5.35 × 109 M−1 s−1. The formation and evolution of oxidation reaction intermediates, short-chain carboxylic acids and inorganic ions were identified by gas chromatography-mass spectrometry, high performance liquid chromatography and ion chromatography analyses, respectively. Based on the identified intermediate and end-products, a plausible mineralization pathway for the oxidation of CYT by hydroxyl radicals is proposed. [ABSTRACT FROM AUTHOR]

High levels of organic pollutant containing industrial wastewaters which are generated during the production of vegetable oils must be treated before discharge to the receiving environments. In this work, treatment of sunflower oil industry wastewater was performed via coagulation-flocculation, electro-Fenton and sequential operation of these two methods. To determine optimum coagulant concentration, flocculant concentration and pH, coagulation-flocculation studies were carried out under 4, 10, 16 g/L PACl and Al2(SO4)3.18H2O coagulant concentrations, 0.06, 0.18, 0.3 g/L anionic commercial polyelectrolyte concentrations and 4, 6, 8 pH values, respectively. Results showed a COD removal of 97% under optimum conditions of 10 g/L Al2(SO4)3.18H2O, 0.06 g/L flocculant concentration and pH 6. Electro-Fenton studies were performed under 1, 2.5, 4 A current intensity, 4.5, 9, 18 g/L FeSO4.7H2O concentration, 32.71, 81.77, 130.84 mM H2O2 concentration, and 3, 5.5, 8 pH conditions. Optimum operating conditions for electro-Fenton method were obtained as 1 A, 9 g/L FeSO4.7H2O, 130.84 mM H2O2, 6.06 H2O2/Fe2+ molar ratio and pH 3. Treatment under optimum conditions revealed 99% COD removal and 2.37 kWh/m3 energy consumption for electro- Fenton method. Sequential coagulation-flocculation-electro-Fenton method under optimum conditions resulted in 98% COD removal and 0.48 kWh/m3 energy consumption at 15 min operation, thus the treated water is dischargeable since COD value (183 mg/L) is below discharge limits. [ABSTRACT FROM AUTHOR]

The rapid and efficient mineralization of the chemotherapeutic drug busulfan (BSF) as the target pollutant has been investigated for the first time by three different heterogeneous EF systems that were constructed to ensure the continuous electro-generation of H 2 O 2 and •OH consisting of: i) a multifunctional carbon felt (CF) based cathode composed of reduced graphene oxide (rGO), iron oxide nanoparticles and carbon black (CB) (rGO-Fe 3 O 4 /CB@CF), ii) rGO modified cathode (rGO/CB@CF) and rGO supported Fe 3 O 4 (rGO-Fe 3 O 4) catalyst and iii) rGO modified cathode (rGO/CB@CF) and multi walled carbon nanotube supported Fe 3 O 4 (MWCNT-Fe 3 O 4) catalyst. The effects of main variables, including the catalyst amount, applied current and initial pH were investigated. Based on the results, H 2 O 2 was produced by oxygen reduction reaction (ORR) on the liquid-solid interface of both fabricated cathodes. •OH was generated by the reaction of H 2 O 2 with the active site of ≡FeII on the surface of the multifunctional cathode and heterogeneous EF catalysts. Utilizing carbon materials with high conductivity, the redox cycling between ≡FeII and ≡FeIII was effectively facilitated and therefore promoted the performance of the process. The results demonstrated almost complete mineralization of BSF through the heterogeneous systems over a wide applicable pH range. According to the reusability and stability tests, multifunctional cathode exhibited outstanding performance after five consecutive cycles which is promising for the efficient mineralization of refractory organic pollutants. Moreover, intermediates products of BSF oxidation were identified and a plausible oxidation pathway was proposed. Therefore, this study demonstrates efficient and stable cathodes and catalysts for the efficient treatment of an anticancer active substance. [Display omitted] • Mineralization of Busulfan (BSF) by heterogeneous electro-Fenton (EF) was examined. • Application of the modified cathode strategies in EF process were performed. • Magnetic heterogeneous EF catalysts (MWCNT-Fe 3 O 4 and rGO-Fe 3 O 4) was fabricated. • Efficiency of cathode-catalyst couple was compared with multifunctional cathode. • High mineralization efficiencies were achieved for the mineralization of BSF. [ABSTRACT FROM AUTHOR]

In this work, effects of agitation speed, inoculum ratio, initial substrate concentraion and incubation temperature were investigated for anaerobic biohydrogen production. The most suitable parameters were determined as agitation speed 200 rpm, microorganism inoculum ratio 1:10 v/v, initial substrate concentration 32.4 g COD/L and temperature 37°C. Under these conditions, 1257 mL H2 production, 17.06 mL H2/g COD yield and 6.441 mL H2/L maximum H2 production rate was reached. For first order elementary reaction rate model, reaction rate constants were calculated as 6.5x10-5 min-1 and 7.92x10-5 min-1 for temperatures of 28°C and 37°C, respectively. Arrhenius constant and activation energy were calculated as 9.74x1034 min-1 and 229.20 kJ/mol respectively. For Michaelis- Menten model, maximum H2 production rates, Michaelis constants and R2 values were calculated as 11.47 mL H2/L.min, 74.66 mL H2/L.min, 181.9 g COD/L, 447.7 g COD/L and 0.9458, 0.9505 for 28ºC and 37°C temperatures, respectively. Using modified Gompertz model, all R2 values were obtained greater than 0.99, maximum H2 production potentials were found as 2.126 L H2/L, 2.777 L H2/L at 28°C and 37°C with 32.4 g COD/L, respectively. Maximum H2 production rate was reached as 15.250 mL H2/L.min at 37°C and 27 g COD/L initial substrate concentration. [ABSTRACT FROM AUTHOR]

In this work, effects of agitation speed, inoculum ratio, initial substrate concentraion and incubation temperature were investigated for anaerobic biohydrogen production. The most suitable parameters were determined as agitation speed 200 rpm (0 - 200 rpm), microorganism inoculum ratio 1:10 v/v (1:10 - 1:200 v/v), initial substrate concentration 32.4 g COD/L (10.8- 32.4 g COD/L) and temperature 37°C (28-37°C). Under these conditions, 1257 mL H2 production, 17.06 mL H2/g KOI yield and 6.441 mL H2/L maximum H2 production rate had been reached. In the case of an incubation temperature of 37°C, the lag phase was observed to be approximately 6.5 h independent of the initial substrate concentration. The relationship between substrate concentration and product formation was evaluated as reaction order of 1 for elementary reaction rate model, reaction rate constants were calculated as 6.5x10-5 min-1 and 7.92x10-5 min-1 for temperatures of 28°C and 37°C, respectively. Arrhenius model parameters, frequency factor and activation energy were calculated as 9.74x1034 min-1 and 229.20 kJ/mol respectively. Maximum H2 production rates, Michaelis constants (KS) and R2 values were calculated as 11.47 mL H2/L.min, 74.66 mL H2/L.min, 181.9 g COD/L, 447.7 g COD/L and 0.9458, 0.9505 for 28°C and 37°C temperatures, respectively. Using modified Gompertz model, all R2 values were obtained greater than 0.99, maximum H2 production potentials were found as 2.126 L H2/L, 2.777 L H2/L at 28°C and 37°C with 32.4 g COD/L, respectively. Maximum H2 production rate was reached as 15.250 mL H2/L.min at 37°C and 27 g COD/L initial substrate concentration. [ABSTRACT FROM AUTHOR]

In this work, effects of agitation speed, inoculum ratio, initial substrate concentraion and incubation temperature were investigated for anaerobic biohydrogen production. The most suitable parameters were determined as agitation speed 200 rpm (0 - 200 rpm), microorganism inoculum ratio 1:10 v/v (1:10 - 1:200 v/v), initial substrate concentration 32.4 g COD/L (10.8- 32.4 g COD/L) and temperature 37°C (28-37oC). Under these conditions, 1257 mL H2 production, 17.06 mL H2/g KOI yield and 6.441 mL H2/L maximum H2 production rate had been reached. In the case of an incubation temperature of 37°C, the lag phase was observed to be approximately 6.5 h independent of the initial substrate concentration. The relationship between substrate concentration and product formation was evaluated as reaction order of 1 for elementary reaction rate model, reaction rate constants were calculated as 6.5x10-5 min-1 and 7.92x10-5 min-1 for temperatures of 28°C and 37°C, respectively. Arrhenius model parameters, frequency factor and activation energy were calculated as 9.74x1034 min-1 and 229.20 kJ/mol respectively. Maximum H2 production rates, Michaelis constants (KS) and R2 values were calculated as 11.47 mL H2/L.min, 74.66 mL H2/L.min, 181.9 g COD/L, 447.7 g COD/L and 0.9458, 0.9505 for 28ºC and 37°C temperatures, respectively. Using modified Gompertz model, all R2 values were obtained greater than 0.99, maximum H2 production potentials were found as 2.126 L H2/L, 2.777 L H2/L at 28°C and 37°C with 32.4 g COD/L, respectively. Maximum H2 production rate was reached as 15.250 mL H2/L.min at 37°C and 27 g COD/L initial substrate concentration. [ABSTRACT FROM AUTHOR]

In this study proportional integral derivative control of pH which is the output variable of paper mill wastewater treatment process with electrocoagulation has been performed. Flow rates of 0.1 M HCl and 0.1 M NaOH solutions have been chosen as manipulated variables. Firstly dynamic analysis and system identification studies have been carried out. pH data was collected by giving step changes to acid and base flow rates and auto regressive moving average with external input models were obtained by using recursive least squares method for each process where pH affected by acid and base flow rates respectively. Models were used in theoretical proportional integral derivative control program coded in MATLAB to determine optimum proportional integral derivative controller parameters by trial and error method. These parameters were then used in real time proportional integral derivative controller coded in MATLAB/Simulink to perform experimental studies. When coordinated control is applied to process by using acid and base flow rates as manipulated variables, pH value ranged from 5 to 11 and it is shown that the highest removal efficiency of turbidity and colour are 98.6% and 99.4%, respectively. [ABSTRACT FROM AUTHOR]

With phase-plane analysis in Matlab, the relations between the bacterial indicators and dissolved oxygen (DO), pH and temperature, was examined by considering the dynamic during 20 September 2013 to 8 February 2014 for water quality monitoring in enclosed coastal waters at the edge of the Kaş region of Turkey. It has been suggested that the bacterial indicator phase plane analysis provides a good method of monitoring. It was shown that temperature (significance value, p=4.9e-05), DO (p=1.0e-04) and pH (p=4.6e- 04) values have a significant effect on bacterial indicators. The relationship between the bacterial indicators was examined by comparing the same scale "cusp" diagrams, and it was demonstrated that total coliforms concentration were closely related with faecal coliforms (FC) concentration. In presenting the enclosed coastal water quality information, weighting average water quality index (WQIMP) has been used by selecting the sets of appropriate parameters. To keep track of and analyse changes over time by calculating the index numbers, the set of seven variables which are FC, DO, pH, temperature, turbidity, nitrate, total suspended solids and the set of three variables which are FC, temperature, DO were utilized successfully (p=8.3e-05). Parameter quality values were obtained from the software developed using cubic hermite polynomial in Matlab. [ABSTRACT FROM AUTHOR]

With phase-plane analysis in Matlab, the relations between the bacterial indicators and dissolved oxygen (DO), pH and temperature, was examined by considering the dynamic during 20 September 2013 to 8 February 2014 for water quality monitoring in enclosed coastal waters at the edge of the Kaş region of Turkey. It has been suggested that the bacterial indicator phase plane analysis provides a good method of monitoring. It was shown that temperature (significance value, p=4.9e-05), DO (p=1.0e-04) and pH (p=4.6e-04) values have a significant effect on bacterial indicators. The relationship between the bacterial indicators was examined by comparing the same scale "cusp" diagrams, and it was demonstrated that total coliforms concentration were closely related with faecal coliforms (FC) concentration. In presenting the enclosed coastal water quality information, weighting average water quality index (WQIMP) has been used by selecting the sets of appropriate parameters. To keep track of and analyse changes over time by calculating the index numbers, the set of seven variables which are FC, DO, pH, temperature, turbidity, nitrate, total suspended solids and the set of three variables which are FC, temperature, DO were utilized successfully (p=8.3e-05). Parameter quality values were obtained from the software developed using cubic hermite polynomial in Matlab. [ABSTRACT FROM AUTHOR]

With phase-plane analysis in Matlab, the relations between the bacterial indicators and dissolved oxygen (DO), pH and temperature, was examined by considering the dynamic during 20 September 2013 to 8 February 2014 for water quality monitoring in enclosed coastal waters at the edge of the Kaş region of Turkey. It has been suggested that the bacterial indicator phase plane analysis provides a good method of monitoring. It was shown that temperature (significance value, p=4.9e-05), DO (p=1.0e-04) and pH (p=4.6e-04) values have a significant effect on bacterial indicators. The relationship between the bacterial indicators was examined by comparing the same scale "cusp" diagrams, and it was demonstrated that total coliforms concentration were closely related with faecal coliforms (FC) concentration. In presenting the enclosed coastal water quality information, weighting average water quality index (WQIMP) has been used by selecting the sets of appropriate parameters. To keep track of and analyse changes over time by calculating the index numbers, the set of seven variables which are FC, DO, pH, temperature, turbidity, nitrate, total suspended solids and the set of three variables which are FC, temperature, DO were utilized successfully (p=8.3e-05). Parameter quality values were obtained from the software developed using cubic hermite polynomial in Matlab. [ABSTRACT FROM AUTHOR]