Intrinsic kinetics for fixed bed bioreactor in hospital wastewater treatment

2016 ◽  
Vol 74 (8) ◽  
pp. 1992-1998 ◽  
Author(s):  
Mehrdad Farrokhi ◽  
Mostafa Mahdavianpour ◽  
Mehdi Shirzad-Siboni ◽  
Mohammad Naimi-Joubani ◽  
Hamzeh Ali Jamali

Variation in hospital wastewater (HWW) pollutants and differences with municipal wastewater (MWW), make the use of biokinetic coefficients obtained from activated sludge in the MWW treatment unprofitable for designing, modeling and evaluation of biological processes for HWW treatment. Since this study was conducted to evaluate the performance and biokinetic coefficients of a fixed bed bioreactor (FBBR) using rice husks as fixed media in HWW treatment, a new modified method was also proposed for biokinetic estimation in FBBR processes. For these purposes, five hydraulic retention times along with five sludge retention times were introduced to a pilot setup and the required data were attained. The performance process for chemical oxygen demand (COD) removal was significant (87.8–97.5%) in different conditions. The values of biokinetic coefficients k, Ks, Y and Kd were obtained as 2.42 (day−1), 55.5 (mgCOD/L), 0.2929 (mgBiomass/mgCOD) and 0.0164 (day−1), respectively. The rice husks with high surface area and high affinity for biomass accumulation on its surface are promising media for a green and environmentally friendly FBBR process. The kinetics parameters values are utilizable for modeling of FBBR using rice husks as fixed media in HWW treatment.

2014 ◽  
Vol 931-932 ◽  
pp. 7-11
Author(s):  
Sutasinee Neramittagapong ◽  
Arthit Neramittagapong ◽  
Siwaporn Choorueang

This work is an investigation of the effectiveness of chemical oxygen demand (COD) removal from synthesized lignin wastewater using photo-Fenton reaction over Fe-Ce-Zn catalysts. The synthesized lignin wastewater had the same COD concentration as the pulp processing wastewater. The treatment was done using photo-Fenton reaction with the metal catalysts (Fe-Ce-Zn). They were prepared by co-precipitation. The catalysts efficacies in reducing COD were tested. It was found that the addition of zinc influenced its reaction due to the increasing of semiconductor property to the light. Moreover, the high surface area of Fe-Ce-Zn catalyst enhanced the COD removal due to the synergy of the high adsorption capacity. Therefore, the Fe-Ce-Zn catalyst was studied to obtain the optimal condition for COD reduction. The conditions and parameters investigated were: pH, the concentration of hydrogen peroxide (H2O2), and the concentration of catalyst. The optimal condition was obtained using the Box-Behnken statistical experiment design (BBD) and the response surface methodology (RSM). It has been found that the pH and the concentration of catalyst had the significant effects on the reduction of COD. The concentration of H2O2 has no effect on the COD removal. The maximum COD removal (60%) was achieved at the pH of 5.2, 4 g/L of catalyst loading, and 366 mg/L of H2O2.


Author(s):  
Dilek Varisli ◽  
Tugba Rona

Abstract Ammonia has become an important source for hydrogen especially for fuel cell applications that require COx free hydrogen. In this study, high surface area Pt incorporated mesoporous siliceous materials were prepared for ammonia decomposition reaction to produce clean hydrogen. The results of a fixed bed flow reactor tests, conducted using pure ammonia showed that Pt-SiO2 type catalysts which were prepared by a one-pot hydrothermal synthesis procedure were very active in ammonia decomposition, such as 72% conversion was reached at 500°C at a gas hourly space velocity of 5,100 ml/h.gcat over the catalyst prepared at Pt/Si mol ratio of 0.03. Activity of the synthesized catalysts increased with an increase in Pt loading. Platinum incorporated siliceous materials prepared by impregnation procedures were also tested in ammonia decomposition and highly promising results were obtained.


2015 ◽  
Vol 1104 ◽  
pp. 51-56 ◽  
Author(s):  
Shi Feng Jiang ◽  
Zhen Qiu Li ◽  
Hong Nan Chen ◽  
Er Qiang Wang

In this research, methyl acrylate has been synthesized from industrial raw material methyl acetate through highly efficient and eco-friendly method, One-step aldol condensation, using acid-base bifunctional catalyst Cs, P and K as catalysts. Carbon deposits and other issues led to the catalysts deactivation in the process of fixed bed, which led to the production interruption. While, the process of circulating fluidized bed can overcome this defect and the catalyst can maintain good catalytic activity in the whole process. Cs (8%), P (5%), K (2%)/γ-Al2O3/ catalyst showed better performance due to its high surface area and more weak basicity and acidity. In addition, theoretical calculations and cold model experiments were also conducted in this work to determine the catalyst particle size,operation gas velocity and gas distributor plate.


Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5867
Author(s):  
Chairul Irawan ◽  
Meilana Dharma Putra ◽  
Hesti Wijayanti ◽  
Rinna Juwita ◽  
Yenny Meliana ◽  
...  

The method of solvothermal by one-step operation has been performed to synthesize of magnetic amine-functionalized sugarcane bagasse biocomposites (SB-MH). The obtained SB-MH contains 62.34% of Fe, 17.8 mmol/g of amine, and a magnetic property of 19.46 emu/g. The biocomposite surface area increased significantly from 1.617 to 25.789 m2/g after amine functionalization. The optimum condition of SB-MH used for Pb(II) ion removal was achieved at pH 5 for 360 min with adsorption capacity of 203.522 mg/g. The pseudo 2nd order was well-fitted to the model of Pb(II) ion adsorption. Meanwhile, other contaminant parameters number of Chemical Oxygen Demand (COD), Total Suspended Solid (TSS), and dye in wastewater were also remarkably reduced by about 74.4%, 88.0%, and 96.7%, respectively. The reusability of SB-MH with 4th repetitions showed only a slight decrease in performance of 5%. Therefore, the proposed magnetic amine-functionalized sugarcane bagasse biocomposites lead to a very potential adsorbent implemented in high scale due to high surface area, easy separation, stable materials and capability to adsorb contaminants from aqueous solution.


2019 ◽  
Vol 15 (1) ◽  
pp. 112-118
Author(s):  
Nastaran Parsafard ◽  
Mohammad Hasan Peyrovi ◽  
Zahra Mohammadian ◽  
Niloofar Atashi

CoMo-supported mesoporous catalysts were synthesized by 50 wt% of HZSM-5 and 50 wt% of FSM-16, KIT-6, and MCM-48. These catalysts were prepared by the wet-impregnation method and pre-sulfided with CS2. The catalytic performance was evaluated for HDS reaction of dibenzothiophene over a temperature range of 250-400 °C in a micro fixed-bed reactor under atmospheric pressure. The supported CoMo bimetallic catalysts were characterized by XRD, XRF, FT-IR, N2 adsorption-desorption, and SEM. The CoMo/KIT-6/HZSM-5 indicate higher activity than other catalysts at 400 °C for dibenzothiophene hydrodesulphurization. Also, the best selectivity to cyclohexylbenzene (CHB) is related to CoMo/FSM-16/HZSM-5. The activation energy was also calculated for all prepared catalysts for the conversions of less than 10%; according to which, the activation energy for CoMo/KIT-6/HZSM-5 is less than other catalysts (~21 kJ/mol) which can be related to the appropriate pore size and high surface area of the support. Copyright © 2020 BCREC Group. All rights reserved 


Author(s):  
Pinar Caglayan ◽  
Sena Yasyerli ◽  
Irfan Ar ◽  
Gulsen Dogu ◽  
Timur Dogu

Hydrogen sulfide sorption activities of manganese oxide and Mn-Fe-Cu mixed oxide sorbents were examined in a fixed bed reactor. Sulfur retention capacity of Mn-O sorbent was found to be quite high at 600 °C both in the absence and presence of hydrogen gas (0.17 and 0.14 g S/g sorbent, respectively). This sorbent has a high porosity and a relatively high surface area. Best regeneration temperature of this sorbent was found as 700 °C, with a gas stream containing 6% oxygen in nitrogen. Mn-Fe-Cu mixed oxide sorbent had a lower sulfur retention capacity (0.07 g S/g sorbent). However, both of these sorbents gave quite high initial sorption rate constants, resulting very sharp breakthrough curves. Deactivation model was shown to give good agreement with the experimental H2S breakthrough curves.


2017 ◽  
Vol 75 (9) ◽  
pp. 2064-2071 ◽  
Author(s):  
Reyad Al Dwairi

The probable use of Jordanian natural zeolitic tuff in wastewater treatment as natural adsorbent for the removal of Cr (VI) ions from aqueous solution in continuous fixed bed columns was tested experimentally and theoretically. The tested zeolitic tuff was obtained from Al Hala volcano (HZ) located in southern part of Jordan and subjected to crushing and sieving only without any further treatment. Experimentally the HZ grains were packed in a fixed bed column. The used grain sizes are HZ1 (1.0–0.60 mm) and HZ2 (0.60–0.30 mm). The adsorption capacity was evaluated using breakthrough curves and by applying the Thomas and Yoon and Nelson models. The Thomas model analysis of the measured breakthrough curves revealed that the adsorbent HZ2 has a higher adsorption capacity to Cr (VI) ions (56.3 mg/g) than HZ1 (35.5 mg/g). The time elapsed to reach 50% breakthrough was determined by the Yoon and Nelson model. The time to reach 50% breakthrough is 318.78 min and 368.18 min for HZ1 and HZ2, respectively. The research results indicate that the small size fraction (HZ2) is more suitable and effective as adsorbent material than the size fraction (HZ1) due to its high surface area.


2015 ◽  
Vol 22 (1) ◽  
Author(s):  
Mishu Singh

The treatment of toxic and inhibitory phenolic compounds using biological techniques have been pursued vas a promising and widely accepted treatment process due to its easiness of handling, a greater level of stabilization of waste and properly operated to prevent the production of secondary pollutants. Up-flow Anaerobic Bio-Reactors (UAFB) has been widely applied for the handling of high organic load industrial wastewater. The treatment of synthetic phenolic wastewater by a single stage anaerobic fixed bed bioreactor with granite stones packing at four different temperatures was studied. The effect of hydraulic retention time on COD reduction and other steady state characteristics and kinetic parameters, which form these characteristics, was also studied. A recirculated single stage up-flow anaerobic bioreactor operated at all the above-given temperatures with initial BOD 1462 mg/l and initial COD 5720 mg/l for a digestion period of 25 days with a working volume of 1000 ml. The performance of the reactor was monitored after every five days and analyzed in terms of percentage (COD, BOD, TS, TDS, VS removal and biogas production). The removal efficiency of BOD, COD, TS, TDS and VS reached a maximum value of 63.20%, 61.24%, 44.88%, 47.67% and 53.12% respectively. With the change in HRT, the maximum COD reduction was 66.04% at 24 hrs HRT at 400C with initial COD of 5000 mg/l. Specific biogas yield increased up to 0.0162 ml/mg CODr.   Keywords— Phenol, anaerobic, fixed bed bioreactor, wastewater, up-flow anaerobic sludge blanket, experimental design, IndiaAbbreviations: BOD -Biochemical Oxygen Demand, COD - Chemical Oxygen Demand,   TDS  - Total Dissolved Solids,  VS - Volatile Solids, UAFB - Up-Flow Anaerobic Fixed Bed Bioreactor


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