Jeremi Naumczyk

Electrochemical treatment of tannery wastewater using Ti/Pt and Ti/Pt/Ir electrodes

Abstract The treatment of tannery wastewater by the electrochemical method using Ti Pt and Ti/Pt/Ir electrodes is investigated. The aim of a satisfactory elimination of NH+4 from wastewaters of different strength was achieved using both types of electrodes. A Ti/Pt/Ir anode proved to have the electrocatalytical properties for NH+4 removal, but it resulted to be more sensitive to poisoning by H2S contained in the wastewater. For both types of the electrodes NH+4 removal followed pseudo-first order kinetics, with the rate decreasing in function of the presence of organic substances. A concurrent removal of COD was observed particularly with a Ti Pt anode, but its magnitude was not sufficient to ensure the discharge limits to be met while treating the raw wastewater only by the electrochemical process. In conclusion the electrochemical process can be applied successfully as a final polishing or an alternative to biological nitrification, but cannot substitute completely the traditional treatment of tannery wastewater.

Cosmetic wastewater treatment by coagulation and advanced oxidation processes

In this study, the treatment process of three cosmetic wastewater types has been investigated. Coagulation allowed to achieve chemical oxygen demand (COD) removal of 74.6%, 37.7% and 74.0% for samples A (Al2(SO4)3), B (Brentafloc F3) and C (PAX 16), respectively. The Fenton process proved to be effective as well – COD removal was equal to 75.1%, 44.7% and 68.1%, respectively. Coagulation with FeCl3 and the subsequent photo-Fenton process resulted in the best values of final COD removal equal to 92.4%, 62.8% and 90.2%. In case of the Fenton process, after coagulation these values were equal to 74.9%, 50.1% and 84.8%, while in case of the H2O2/UV process, the obtained COD removal was 83.8%, 36.2% and 80.9%. High value of COD removal in the Fenton process carried out for A and C wastewater samples was caused by a significant contribution of the final neutralization/coagulation. Very small effect of the oxidation reaction in the Fenton process in case of sample A resulting from the presence of antioxidants, ‘OH radical scavengers’ in the wastewater.

Landfill Leachates Treatment by /UV, /, Modified Fenton, and Modified Photo-Fenton Methods

Advanced oxidation processes (AOPs) such as H2O2/UV, O3/H2O2, modified Fenton, and modified photo-Fenton processes have been investigated in terms of the treatment of landfill leachate with ratio of BOD5/COD in the range of 0.22 to 0.24. The modification of Fenton and photo-Fenton processes consisted in the inclusion of precipitation and separation of humic substances at pH 3. Due to the precipitation, the value of COD decreased by 39% and BOD5 by 7.1%. The modification of the processes allowed us to improve the efficiency and to decrease the doses of reagents necessary to continue the process. Modified photo-Fenton process proved to be the most effective (92.7% COD removal) of all processes investigated. Additionally, modified-Fenton process was much more effective than the other two processes when compared up to 120 min, while after longer times it gave the least satisfactory results. After 30 min of modified-Fenton process BOD5/COD ratio increased to 0.43. The parameter referred to as “efficiency of oxidants” was used to estimate the efficiency of all the processes—its value varied from 178 to 239%. Various substances including phthalates, hydrocarbons, silanes, and siloxanes were identified in raw and treated leachate.

Organics isolation from fresh and drinking waters by macroporous anion-exchange resins

Abstract A research on the isolation of organic pollutants from water is presented. Five macroporous anionic resins: Varion AT400, Asmit 229N, Zerolite 553N, Wofatite EA60 and Amberlite IR93 were used for humic substances and other anionic organics isolation. Varion AT400 resulted to be the best anionic resin (about 90% recovery of humic substances and a lower recovery for other anionic substances). Nearly complete desorption was achieved by NaCl/NaOH 10%/2% solution, at a volume of about 3.5 times the resin bed volume.

Cosmetic wastewater treatment using the Fenton, Photo-Fenton and H2O2/UV processes

Advanced Oxidation Processes (AOPs), such as the Fenton, photo-Fenton and H2O2/UV processes, have been investigated for the treatment of cosmetic wastewaters that were previously coagulated by FeCl3. The Photo-Fenton process at pH 3.0 with 1000/100 mg L−1 H2O2/Fe2+ was the most effective (74.0% Chemical Oxygen Demand (COD) removal). The Fenton process with 1200/500 mg L−1 H2O2/Fe2+ achieved a COD removal of 72.0%, and the H2O2/UV process achieved a COD removal of 47.0%. Spreading the H2O2 doses over time to obtain optimal conditions did not improve COD removal. The kinetics of the Fenton and photo-Fenton processes may be described by the following equation: d[COD]/dt = -a[COD] tm (t represents time and a and m are constants). The rate of COD removal by the H2O2/UV process may be described by a second-order reaction equation. Head Space, Solid-Phase MicroExtraction, Gas Chromatography and Mass Spectrometry (HS-SPME-GC-MS) were used to identify 48 substances in precoagulated wastewater. Among these substances, 26 were fragrances. Under optimal AOP conditions, over 99% of the identified substances were removed in 120 min.

Landfill Leachate Treatment by Fenton, Photo-Fenton Processes and their Modification

Abstract Efficiency of leachate treatment in Fenton, photo-Fenton processes and their modifications was studied. Process was modified by leachate acidification, followed by the precipitate separation and continuing the processes. Acidification to pH 2.0 and 3.0 led to 34.3% and 18.9% COD removal respectively. The efficiency of the processes was decreasing as follows: modified photo-Fenton pH 2.0 (96.5% COD removal) > photo-Fenton pH 2.0 (95.0%) > modified photo-Fenton pH 3.0 (89.2%) > photo-Fenton pH 3.0 (85.9%) > modified Fenton pH 2.0 (79.5%) > Fenton pH 2.0 (77.6%) > modified Fenton pH 3.0 (64.8%) > Fenton pH 3.0 (63.5%). At the beginning of the processes the coagulation contribution was higher (up to 73% of total COD removal), while finally it was exceeded by Fenton reaction contribution (up to 66% of total COD removal). Empirical formula for Fenton reaction kinetics was proposed.

Organics isolation from fresh and drinking waters by macroporous Nonionic sorbents

In this paper the results on the isolation of organic water pollutants by nonionic sorbents are presented. Polish active carbon Z4S, Amberlite XAD‐2, XAD‐4, XAD‐7 and Polish nonionic macroporous sorbents were used. Adsorption effectiveness, as influenced by organics polarity and concentration, by contact time and by filtered water volume was examined. The best parameters for isolation with macroporous nonionic sorbents were established. For the desorption of organic substances, a Soxhlet extraction for 12hrs with dichloromethane is proposed. The investigated sorbents give total recoveries very close to those obtained by Amberlite XAD resins.

Electrochemical treatment of tannery wastewater—Raw, coagulated, and pretreated by AOPs

ABSTRACT This study on tannery wastewater treatment showed that indirect electrooxidation by chlorine generated at a Ti/SnO2/PdO2/RuO2 (SPR) anode led to full ammonia removal, and a decrease in chemical oxygen demand (COD) of up to 77.0%. A combined process of coagulation + H2O2/UV + electrooxidation allowed us to achieve a decrease in COD of up to 97.5%. Equations describing the kinetics of the decrease in COD, the relationship between the decrease in COD and current, and the relationship between the current efficiency of COD reduction and the initial concentrations of the reagents were established. The changes in the Adsorbable Organically Bound Halogen (AOX) value were determined, and the individual compounds, including chloroorganics, present in raw and treated wastewater were identified by gas chromatography mass spectrometry (GC-MS). Values of AOX increased in the initial phase of electrooxidation, while afterwards they decreased.

Cosmetic wastewater treatment by the ZVI/H2O2 process

ABSTRACT The ZVI/H2O2 process was applied for cosmetic wastewater treatment. Two commercial zero-valent iron (ZVI) types with different granulations were chosen: Hepure Ferrox PRB and Hepure Ferrox Target. In addition, the pH and stirring method influence on ZVI/H2O2 process efficiency was studied. During the ZVI and ZVI/H2O2 processes, linear Fe ions concentration increase was observed. The addition of H2O2 significantly accelerated the iron dissolution process. The highest COD removal was obtained using finer ZVI (Hepure Ferrox Target) for doses of reagents ZVI/H2O2 1500/1600 mg/L, in a H2O2/COD weight ratio 2:1, at pH 3.0 with stirring on a magnetic stirrer. After 120 min of the process, 84.0% COD removal (from 796 to 127 mg/L) was achieved. It was found that the efficiency of the process depends, as in the case of the Fenton process, on the ratio of the reagents (ZVI/H2O2) and their dose in relation to the COD (H2O2/COD) but does not depend on the dose of the iron itself. Statistical analysis confirms that COD removal efficiency depends primarily on H2O2/COD ratio and ZVI granulation, but ZVI dose influence is not statistically significant. The head space, solid-phase microextraction, gas chromatography, mass spectrometry results confirm high efficiency of the ZVI/H2O2 process.

Cosmetic wastewater treatment using dissolved air flotation

Abstract Five cosmetics wastewater samples were treated by Dissolved Air Flotation (DAF) assisted by coagulation. Different aluminum based coagulants were used: (Al2(SO4)3, Al 1019, Al 3010, Al 3030, Al 3035, PAX 16 and PAX 19). The raw wastewater COD values were in the range 285-2124 mg/l. The efficiency of DAF depended on different coagulants and production profi le of factory. COD removal was varied from 11.1 to 77.7%. The efficiency of coagulants was similar during treatment of particular sample. The best results were obtained with Al2(SO4)3 and for sample 5 - lotions and shampoos production. The wastewater from UV fi lter creams production (sample 4) was resistant to treatment by DAF regardless of used coagulant. HS-SPME-GC-MS analysis can be a confirmation of DAF effectiveness