Methane fermentation of the excess sludge sonicated and oxidized with Fenton's reagent

2021 ◽  
Vol 232 ◽  
pp. 216-224
Author(s):  
Iwona Zawieja ◽  
Malgorzata Worwag ◽  
Kinga Brzeska
2019 ◽  
Vol 116 ◽  
pp. 00104
Author(s):  
Iwona Zawieja ◽  
Kinga Brzeska

The advanced oxidation processes (AOPs) play an important role in the degradation of hardly decomposable organic pollutants. AOPs methods rely on the production of highly reactive hydroxyl OH• radicals. The aim of the conducted research was to intensify biogas production in the methane fermentation process of excess sludge subjected to the process of deep oxidation with Fenton's reagent. In the process of oxidation of sewage sludge with the Fenton reagent, doses of iron ions in the range 0.02–0.14 g Fe2+/g TS (total solids) were used Hydrogen peroxide was measured in the proportions 1: 1–1:10 in relation to the mass of iron ions. The basic substrate of the study was excess sludge. In the case of excess sludge oxidation with the use of Fenton's reagent, the most favorable process conditions were considered to be the dose of iron ions 0.08 g Fe2+/g d.m. and a Fe2+: H2O2 ratio of 1:5. As a result of subjecting the excess sludge to disintegration with the Fenton reagent in the above-mentioned dose, with respect to the fermentation process of unprocessed sludge, about two-fold increase in the digestion degree of excess sludge and about 35% increase of the biogas yield was obtained.


2017 ◽  
Vol 77 (1) ◽  
pp. 204-210 ◽  
Author(s):  
Hongying Yuan ◽  
Yuping Yang ◽  
Jian Yuan ◽  
Yanning Wang ◽  
Yameng Song ◽  
...  

Abstract The dewaterability of excess sludge significantly improved upon pretreatment with Fenton's reagent in this study. After 0.9 g/L of Fe2+ and 5.0 g/L of H2O2 were added to the sludge, and reacted for 2 h at pH = 4, the specific resistance to filtration (SRF) of the excess sludge decreased from an initial value of 29.74 × 1012 m/kg to 6.49 × 1012 m/kg. The factors that affected this improvement in sludge dewaterability as evaluated by SRF reduction showed the following order: H2O2 > pH > Fe2+ > reaction time. Furthermore, the hydrolysis performance of the sludge under the optimal reaction conditions was investigated. The results indicated that the concentration of soluble chemical oxygen demand in the supernatant increased almost 14 times compared to raw sludge, and the contents of soluble protein and soluble polysaccharide were more than 8 and 17 times higher, respectively, than for the untreated situation. However, the amounts of ammonia nitrogen (NH4+-N) and phosphate (PO43−-P) released from the sludge showed different trends: NH4+-N increased by 200%, while PO43−-P decreased by 82%. The production of volatile fatty acids (VFAs) from the treated sludge showed that total VFAs increased by 66%, and iso-butylacetic acid was the dominant product among the total VFAs.


2001 ◽  
Vol 44 (10) ◽  
pp. 327-332 ◽  
Author(s):  
M.-C. Lu ◽  
C.-J. Lin ◽  
C.-H. Liao ◽  
W.-P. Ting ◽  
R.-Y. Huang

The specific filtration resistance, moisture, and SVI were used to evaluate the influence of pH on the filtration and dewatering efficiencies when applying Fenton's reagent to treat the excess sludge. The excess sludge used in this study was obtained from the wastewater treatment plant of An-Ping Industrial Park in Tainan, Taiwan. Results show that initial pH has no significant effect on the filtration efficiency of sludge by using the Fenton (Fe2+/H2O2) system as the treatment process. However, the reduction of specific resistance by Fenton-like (Fe3+/H2O2) process decreased suddenly to a level similar to that obtained from the control experiment at initial pH > 4.5. For the moisture of cake sludge, both Fenton and Fenton-like systems have the same tendency; the moisture of cake sludge increased slightly with increasing the initial pH. The SVI values for Fenton process decreased with increasing the initial pH, but the opposite result was obtained from the Fenton-like and control system; higher pH was not favorable for the sludge settling.


2000 ◽  
Vol 9 (4) ◽  
pp. 331-345 ◽  
Author(s):  
Katherine R. Weeks ◽  
Clifford J. Bruell ◽  
Nihar R. Mohanty

Tetrahedron ◽  
1963 ◽  
Vol 19 (11) ◽  
pp. 1705-1710 ◽  
Author(s):  
G.J. Moody

1982 ◽  
Vol 104 (13) ◽  
pp. 3783-3783
Author(s):  
Cheves Walling ◽  
Kalyani Amarnath ◽  
Curt Campbell

2021 ◽  
Vol 25 (7) ◽  
pp. 8-12
Author(s):  
P. Rajendran ◽  
K. Geethu ◽  
P. Bashpa ◽  
K. Bijudas

Congo red is a toxic azo dye which is used extensively in industries like textile, paper, pulp and paper. Very high amount of Congo red from these industrial sources is discharged into natural water bodies resulting environmental pollution. The present work reports the kinetics and mechanism of oxidative decomposition of Congo red by Fenton’s reagent in homogeneous medium and also under ultra violet light irradiation. Kinetic parameters like effect of [Fe2+], [H2O2], [Congo red] and temperature on the decomposition of Congo red were studied. The reaction is found to be fractional order with [Fe2+] and first order with [H2O2] and [Congo red]. The rate of oxidative decomposition of Congo red by Fenton’ reagent showed a rapid increase of three times when irradiated with ultra violet radiation and completion of reaction occurred within 5-6 minute. Various thermodynamic variables were determined and the presence of isosbestic points on sequential scanning of oxidation kinetics proves that the reaction is very smooth, spontaneous and endothermic. A suitable mechanism is suggested based on the experimental results obtained.


1997 ◽  
Vol 36 (12) ◽  
pp. 215-222 ◽  
Author(s):  
Shyh-Fang Kang ◽  
Huey-Min Chang

This study was designed to use both artificial and real textile secondary effluents to evaluate (1) the COD and color removal efficiencies for ferrous coagulation and Fenton's coagulation, and (2) the feasibility of using hydrogen peroxide to improve ferrous coagulation to meet more stringent effluent standards. The results indicate that the optimum pHs for both ferrous coagulation and Fenton's preoxidation processes range between 8.0–10 and 3.0–5.0, respectively. The rate for color removal is faster than that for COD removal in the Fenton's preoxidation process. The removals of COD and color are mainly accomplished during Fenton's preoxidation step. The ratio of COD removal for Fenton's coagulation versus ferrous coagulation, given the same ferrous dosage, ranges from 1.4 to 2.3, and it ranges from 1.1 to 1.9 for color removal, using two effluent samples. Therefore, using hydrogen peroxide can enhance the ferrous coagulation, and this ensures more stringent effluent standards of COD and color are met.


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