Treatment of Pharmaceutical Sludge by Fenton Oxidation Process

Journal of hazardous …, 2006

The applicability of Fenton's oxidation to improve the biodegradability of a pharmaceutical wastewater to be treated biologically was investigated. The wastewater was originated from a factory producing a variety of pharmaceutical chemicals. Treatability studies were conducted under laboratory conditions with all chemicals (having COD varying from 900 to 7000 mg/L) produced in the factory in order to determine the operational conditions to utilize in the full-scale treatment plant. Optimum pH was determined as 3.5 and 7.0 for the first (oxidation) and second stage (coagulation) of the Fenton process, respectively. For all chemicals, COD removal efficiency was highest when the molar ratio of H 2 O 2 /Fe 2+ was 150-250. At H 2 O 2 /Fe 2+ ratio of 155, 0.3 M H 2 O 2 and 0.002 M Fe 2+ , provided 45-65% COD removal.

Water Science & Technology

Characterisation tests were conducted to determine the feasibility of land application of the sludges produced in wastewater treatment by means of Fenton's Reagent. Physicochemical and microbiological parameters of Fenton sludges were compared to the values obtained for raw alum sludges. The Fenton sludges presented preferable characteristics such as the specific resistance to filtration (SRF), metals and pathogen content (fecal and tot al coliforms, helminth ova, and Salmonella sp.). The SRF ofthe Fenton sludges (1.55 x 10(13) m/kg) was 24% less than the alum sludge value (1.92 x 10(13) m/kg). The concentrations of fecal coliforms (0 MPN/g TS), Salmonella sp. (0 MPN/g TS), Helminth ova (22 HH/g TS) and metals correspond to the limits for biosolids of Class B for land application of the Mexican legislation. The Fenton reagent efficiently removes most of the pathogens, considered by the norms, by means of the combined action of the different stages that constitute this process. T...

Pharmaceutical industry often generates highly toxic wastewater and sludge depending upon the used manufacturing process and season. Effluent from pharmaceutical industry has a COD value in the range of 4000 to 1000. Fenton’s reagent is used in the reduction of COD from the pharmaceutical industry wastewater in this study. The ferrous and hydrogen peroxide were used in molar ratio of 1:1, 1:2 and 1:3. Ferrous was added in the form of ferrous sulphate. A reaction time of one hour was decided for the purpose of reducing COD. A magnetic stirrer was used for mixing the Fenton’s reagent and the wastewater sample. Different doses of hydrogen peroxide and ferrous sulphate was added as per the ratio decided. 89% reduction of COD was observed at 7350 mg/L of ferrous sulphate and 900 mg/L of hydrogen peroxide for 1:1 ratio. For a ratio of 1:2 an efficiency of 87% COD reduction was observed at doses of 3267 mg/L of ferrous sulphate and 800 mg/L of hydrogen peroxide. For a ratio of 1:3 maximum reductions of COD was observed in doses of 2450 mg/L of ferrous sulphate and 900 mg/L of hydrogen peroxide. COD reduction was maximum for a reaction time of 1 hour. Also, increase in the reaction time did not aid in COD reduction.

Waste Management and the Environment IV, 2008

Due to the wide variety of products produced in a drug manufacturing plant, pharmaceutical industry wastewater is a wastewater that is not amenable to conventional biological treatment. In this study, this wastewater was chemically pretreated using Fenton's reagent, since the initial values of the biokinetic coefficients before Fenton indicated that this wastewater could not be biologically treated. A factorial experimental procedure was designed in order to examine the influence of Fenton's pretreatment on biological oxidation. Although the Fenton oxidation process was not very effective, the overall efficiency mounted up to almost 80% in some cases. The optimum experimental conditions for the oxidation of pharmaceutical wastewater were found to be the following: FeSO 4 •7H 2 O concentration 2 g•L-1 , H 2 O 2 concentration 2 mL•L-1. It was proved that after the Fenton process, the substrate was rendered significantly more biodegradable since the maximum specific uptake rate K max was increased from 1,76 to 3,14 gCOD•gVSS-1 •d-1 , whereas the inhibitory coefficient K s was decreased from 3752 to 732 mg•L-1. Conclusively, Fenton oxidation could be a feasible method for the pretreatment of pharmaceutical wastewater.

CLEAN - Soil, Air, Water, 2011

Fenton process was investigated for the purpose of biological sludge disintegration. The Box-Wilson experimental design was employed to evaluate the effects of major process variables (Fe(II) and H 2 O 2 concentrations) on both disintegration and dewatering performance of sludge. Results showed that 4 g Fe(II)/kg total solids (TSs) and 60 g H 2 O 2 /kg TS are efficient for floc disintegration. Fenton pre-treatment enhanced the biodegradability of sludge. For 4 g Fe(II)/kg TS and 60 g H 2 O 2 /kg TS, 19.4% higher methane production was achieved compared to raw sludge in biochemical methane potential assay. Fenton pre-treatment resulted in the release of organic sludge components into the liquid phase. For 4 g Fe(II)/kg TS and 60 g H 2 O 2 /kg TS, dissolved organic carbon and total nitrogen in sludge's supernatant increased by 75.74 and 60.60%, respectively. Fenton pre-treatment enhanced the filterability of sludge and it can be applied for conditioning purpose before mechanical dewatering units.

Water Science & Technology, 2009

The Fenton chemistry comprises both the classical Fenton reagent and its modification, so-called Fenton-like techniques, which have received great attention as a promising technology for wastewater treatment. In the present study real wastewater from different sources (leachate from oil shale semicoke landfill, pharmaceutical effluents from medical ointment production, municipal landfill leachate and wastewater originated from food-processing) were treated by means of Fenton/Fenton-like systems. The effectiveness of wastewater treatment was assessed by COD removal. Additionally, biodegradability improvement (BOD7/COD) and acute toxicity reduction of investigated wastewater samples were observed. The application of the Fenton chemistry to wastewater samples with different origin resulted generally in 70% or higher COD removal. Thus, the Fenton could be effectively applied both as a single treatment method and pre-treatment step to improve subsequent biodegradability of wastewater eff...

Proceedings of the WasteSafe, 2011

Abstract In these years, due to the increasing presence of molecules in industrial waste water from factories and petroleum refineries, the conventional biological methods cannot be used for complete treatment of the effluent therefore the need to newer technologies to degrade these refractory molecules into smaller molecules became very imperative. Advanced oxidation processes (AOPs) constitute a promising technology for the treatment of wastewaters. Fenton’s oxidation was one of the best known metal catalyzed oxidation reactions of water-miscible organic compounds. The mixture of FeSO4 or any other ferrous complex and H2O2 (Fenton’s reagent) at low enough pH, results in Fe2+ catalytic decomposition of H2O2 and proceeds via a free radical chain process that produces hydroxyl radicals which have extremely high oxidizing ability and could oxidize hard to decompose organic compounds in a short time. This work aims at highlighting Fenton’s oxidation processes operating at ambient conditions viz. photo-catalytic oxidation, Fenton’s chemistry and use of hydrogen peroxide. The pre-oxidation of an extremely polluted pharmaceutical wastewater, Direct Blue 71 (DB71) oil recovery industry wastewater, the fish canning industrial wastewater, Active pharmaceutical intermediates (API) in waste waters by Fenton’s oxidation process to degrade organic pollutants. The work highlights the basics of these individual processes including the reactor design aspects, the optimum parameters such as dosage of ferrous sulfate and hydrogen peroxide, pH and initial concentration of pollutants and a complete overview of the various applications to wastewater treatment by Fenton’s oxidation processes in the recent years. This study presents a general review on the effectiveness of Fenton’s technique for the treatment of semi-aerobic landfill leachate (Treatment with Fenton’s reagent appears to be an appropriate method for oxidizing recalcitrant

Water Research, 2001

Fenton reagent has been used to test the degradation of different organic compounds (formic acid, phenol, 4-chlorophenol, 2,4-dichlorophenol and nitrobenzene) in aqueous solution. A stoichiometric coefficient for the Fenton reaction was found to be 0.5 mol of organic compound/mol of hydrogen peroxide, except for the formic acid where a value of approximately one was obtained (due to the direct formation of carbon dioxide). The treatment eliminates the toxic substances and increases the biodegradability of the treated water (measured as the ratio BOD5/COD). Biodegradability is attained when the initial compound is removed.

Environmental Science and Pollution Research, 2016

A novel approach to improve the efficiency of Fenton treatment for sludge reduction through the implication of a deflocculating agent citric acid, for the exclusion of extracellular polymeric substances (EPS) from waste activated sludge (WAS). Deflocculation was achieved with 0.06 g/g suspended solids (SS) of citric acid dosage. Fenton optimization studies using Response Surface Methodology (RSM) revealed that 0.5 g/g SS and 0.0055 g/g SS were the optimal dosages of H2O2 and Fe 2+. The addition of a cation binding agent set the pH value of the sludge to 5 which did not affect the Fenton efficiency. The results presented in this study shows the advantage of deffloculating the sludge as SS and volatile suspended solids (VSS) reductions were found to be higher in the deflocculated (53% and 63%) than in the flocculated sludge (22% and 34%). Kinetic investigation of the treatment showed that the rate of the reaction was four times higher in the deflocculated sludge than control. The methodology reported in this manuscript was successfully applied to a real case were the deflocculated mediated Fenton process reduced the sludge disposal cost from 297.8 US dollar/ton to 61.9 US dollar/ton of sludge.