scholarly journals Optimizing the Hydrothermal Carbonization of Sewage Sludge—Response Surface Methodology and the Effect of Volatile Solids

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1225
Author(s):  
Tobias Blach ◽  
Markus Engelhart
Keyword(s):  
Reaction Time ◽  
Sewage Sludge ◽  
Response Surface ◽  
Reaction Temperature ◽  
Hydrothermal Carbonization ◽  
Process Water ◽  
Heating Value ◽  
Box Behnken Design ◽  
Water Load ◽  
Volatile Solids

This study focuses on identifying the optimum conditions of sewage sludge hydrothermal carbonization by Box–Behnken Design and on the effects of volatile solids on heating value and on process water load. To get insight into the solid and process water characteristics, we applied the Box–Behnken Design on the hydrothermal reaction temperature (190, 220, 250 °C), reaction time (0.5, 2.25, 4 h) and pH (3.9, 5, 6.1). The response surface of the liquid phase revealed decreasing dissolved organic carbon (DOC) concentrations with increasing temperature from 9446 mg/L (190 °C) to 7402 mg/L (250 °C) at 4 h reaction time. For the same hydrothermal conditions, NH4-N concentration increased from 754 to 1230 mg/L. Reaction temperature was identified as the most important process parameter, whereas reaction time and pH had only minor effects. Moreover, linear coefficients of the models were more decisive than the interrelation and quadratic coefficients. Volatile solids (VS) of the feedstock were found to significantly influence both the load of the process water and the change in heating value of the hydrochars. Process water load increased steadily with higher VS. The heating value only increased with more than around 65–80% VS in feedstock.

Optimization of Magnesium Separation and Extraction from Boron Slurry Using Response Surface Methodology

2011 ◽  
Vol 366 ◽  
pp. 366-369
Author(s):  
Feng Gao ◽  
Rong Fu ◽  
Ming Yang Qian ◽  
Zhu Min Wang ◽  
Xiang Zhang
Keyword(s):  
Response Surface Methodology ◽  
Reaction Time ◽  
Factorial Design ◽  
Response Surface ◽  
Reaction Temperature ◽  
Fractional Factorial Design ◽  
Design Criterion ◽  
Fractional Factorial ◽  
Effective Factors

Response surface methodology was used to optimize the soaking Mg leaching ratio from the boron slurry screened by 25 fractional factorial design. Five effective factors such as H2SO4 concentrations, reaction time, reaction temperature and stir velocity were tested by using 25 fractional factorial design criterion and three effective factors H2SO4 concentrations, reaction time and reaction temperature showed significant effect(P2SO4 concentrations of 0.29mol/l, reaction time of 90 min and reaction temperature of 50°C. Three runs of additional confirmation experiments were conducted. The mixture magnesium leaching value was 58.20%.

scholarly journals Optimization of Synthesis of Seleno-Sargassum fusiforme(Harv.) Setch. Polysaccharide by Response Surface Methodology, Its Characterization, and Antioxidant Activity

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Yu-Bin Ji ◽  
Fang Dong ◽  
Miao Yu ◽  
Long Qin ◽  
Dan Liu
Keyword(s):  
Antioxidant Activity ◽  
Response Surface Methodology ◽  
Reaction Time ◽  
Response Surface ◽  
Reaction Temperature ◽  
Sargassum Fusiforme ◽  
Synthesis Conditions ◽  
Optimum Reaction ◽  
Series Of Experiments

The response surface methodology was employed to optimize the synthesis conditions of seleno-Sargassum fusiforme(Harv.) Setch. polysaccharide. Three independent variables (reaction time, reaction temperature, and ratio of Na2SeO3to SFPSI) were tested. Furthermore, the characterization and antioxidant activity of Se-SFPSIin vivowere investigated. The result showed that the actual experimental Se content of Se-SFPSI was 3.352 mg/g at the optimum reaction conditions of reaction time 8 h, reaction temperature 71°C, and ratio of Na2SeO3to SFPSIB 1.0 g/g. A series of experiments showed that the characterization of Se-SFPSIB was significantly different from that of SFPSIB. Additionally, antioxidant activity assay indicated that the Se-SFPSIB could increase catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) activity of mice bearing tumor S180in blood, heart, and liver while decreasing malondialdehyde (MDA) levels. It can be concluded that selenylation is a feasible approach to obtain seleno-polysaccharide which was utilized as highly biological medicine or functional food.

scholarly journals Optimization of Enzymatic Synthesis of Betulinic Acid Amide in Organic Solvent by Response Surface Methodology (RSM)

2019 ◽  
Vol 19 (4) ◽  
pp. 849
Author(s):  
Nurul Atikah Amin Yusof ◽  
Nursyamsyila Mat Hadzir ◽  
Siti Efliza Ashari ◽  
Nor Suhaila Mohamad Hanapi ◽  
Rossuriati Dol Hamid
Keyword(s):  
Response Surface Methodology ◽  
Reaction Time ◽  
Response Surface ◽  
Reaction Temperature ◽  
Betulinic Acid ◽  
Enzymatic Synthesis ◽  
Acid Amide ◽  
Molar Ratio ◽  
Percentage Yield ◽  
Substrate Molar Ratio

Optimization of the lipase catalyzed enzymatic synthesis of betulinic acid amide in the presence of immobilized lipase, Novozym 435 from Candida antartica as a biocatalyst was studied. Response surface methodology (RSM) and 5-level-4-factor central-composite rotatable design (CCRD) were employed to evaluate the effects of the synthesis parameters, such as reaction time (20–36 h), reaction temperature (37–45 °C), substrate molar ratio of betulinic acid to butylamine (1:1–1:3), and enzyme amounts (80–120 mg) on the percentage yield of betulinic acid amide by direct amidation reaction. The optimum conditions for synthesis were: reaction time of 28 h 33 min, reaction temperature of 42.92 °C, substrate molar ratio of 1:2.21, and enzyme amount of 97.77 mg. The percentage yield of actual experimental values obtained 65.09% which compared well with the maximum predicted value of 67.23%. The obtained amide was characterized by GC, GCMS and 13C NMR. Betulinic acid amide (BAA) showed a better cytotoxicity compared to betulinic acid as the concentration inhibited 50% of the cell growth (IC50) against MDA-MB-231 cell line (IC50 < 30 µg/mL).

scholarly journals Study on optimal adsorption conditions of norfloxacin in water based on response surface methodology

2022 ◽  
Author(s):  
Ming Zhang ◽  
Kuo Zhang ◽  
Jinpeng Wang ◽  
Runjuan Zhou ◽  
Jiyuan Li ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Reaction Temperature ◽  
Polynomial Regression ◽  
Single Factor ◽  
Solution Ph ◽  
Box Behnken Design ◽  
Simulated Wastewater ◽  
Predicted Values ◽  
Single Factor Experiment

Abstract The waste pomelo peel was pyrolyzed at 400 °C to prepare biochar and used as adsorbent to remove norfloxacin (NOR) from simulated wastewater. The adsorption conditions of norfloxacin by biochar were optimized by response surface methodology (RSM). On the basis of single-factor experiment, the adsorption conditions of biochar dosage, solution pH and reaction temperature were optimized by Box-Behnken Design (BBD), and the quadratic polynomial regression model of response value Y1 (NOR removal efficiency) and Y2 (NOR adsorption capacity) were obtained respectively. The results show that the two models are reasonable and reliable. The influence of single factor was as follows: solution pH &gt; biochar dosage &gt; reaction temperature. The interaction between biochar dosage and solution pH was very significant. The optimal adsorption conditions after optimization were as follows: biochar dosage = 0.5 g/L, solution pH = 3, and reaction temperature = 45 °C. The Y1 and Y2 obtained in the verification experiment were 75.68% and 3.0272 mg/g, respectively, which were only 2.38% and 0.0242 mg/g different from the theoretical predicted values of the model. Therefore, the theoretical model constructed by response surface methodology can be used to optimize the adsorption conditions of norfloxacin in water.

scholarly journals Cu2+ Montmorillonite K10 Clay Catalyst as a Green Catalyst for Production of Stearic Acid Methyl Ester: Optimization Using Response Surface Methodology (RSM)

2018 ◽  
Vol 13 (1) ◽  
pp. 187 ◽  
Author(s):  
Enas A. Almadani ◽  
Farah W. Harun ◽  
Salina M. Radzi ◽  
Syamsul K. Muhamad
Keyword(s):  
Reaction Time ◽  
Methyl Ester ◽  
Stearic Acid ◽  
Response Surface ◽  
Reaction Temperature ◽  
Acid Methyl Ester ◽  
Montmorillonite K10 ◽  
Acid Methyl ◽  
Stearic Acid Methyl Ester ◽  
Clay Catalyst

Clay catalyst has received much attention to replace the homogeneous catalysts in the esterification reaction to produce fatty acid methyl ester as the source of biodiesel as it is low cost, easily available, as well as environmental friendly. However, the use of unmodified clay, in particular montmorillonite K10 (MMT K10), for the esterification of fatty acids showed that the acid conversion was less than 60% and this is not preferable to the production of biodiesel. In this study, synthesis of stearic acid methyl ester using Cu2+-MMT K10 (Cu-MMT K10) was successfully optimized via response surface methodo-logy (RSM) based on 3-variable of Box-Behnken design (BB). The parameters were; reaction time (5-180 minutes), reaction temperature (80-120 oC) and concentration of Cu2+ in MMT K10 (0.25-1 M). The use of RSM in optimizing the conversion of stearic acid was successfully developed as the actual experimental conversion of stearic acid was found similar to the actual values under the optimum conditions. The model equation predicted that the following conditions would generate the maximum conversion of stearic acid (87.05 %reaction time of 62 minutes, a reaction temperature of 80 oC and catalyst used is 1.0 M Cu-MMT K10. This finding can be considered as green catalytic process as it worked at moderate reaction temperature using low cost clay catalyst with a short reaction time. Copyright © 2018 BCREC Group. All rights reservedReceived: 26th July 2017; Revised: 13rd January 2018; Accepted: 13rd January 2018; Available online: 22nd January 2018; Published regularly: 2nd April 2018How to Cite: Almadani, E.A., Harun, F.W., Radzi, S.M., Muhamad, S.K. (2018). Cu2+ Montmorillonite K10 Clay Catalyst as a Green Catalyst for Production of Stearic Acid Methyl Ester: Optimization Using Response Surface Methodology (RSM). Bulletin of Chemical Reaction Engineering & Catalysis, 13 (1): 187-195 (doi:10.9767/bcrec.13.1.1397.187-195) 

scholarly journals Hydrothermal carbonization of primary sewage sludge and synthetic faeces: Effect of reaction temperature and time on filterability

2015 ◽  
Vol 34 (5) ◽  
pp. 1279-1290 ◽  
Author(s):  
Eric Danso-Boateng ◽  
Richard G. Holdich ◽  
Andrew D. Wheatley ◽  
Simon J. Martin ◽  
Gilbert Shama
Keyword(s):  
Sewage Sludge ◽  
Reaction Temperature ◽  
Hydrothermal Carbonization

scholarly journals Subcritical Water Extraction of Chlorella pyrenoidosa: Optimization through Response Surface Methodology

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Selvakumar Thiruvenkadam ◽  
Shamsul Izhar ◽  
Yoshida Hiroyuki ◽  
Razif Harun
Keyword(s):  
Response Surface Methodology ◽  
Reaction Time ◽  
Response Surface ◽  
Reaction Temperature ◽  
Subcritical Water ◽  
Chlorella Pyrenoidosa ◽  
Water Extraction ◽  
Biofuel Production ◽  
Oil Yield ◽  
Subcritical Water Extraction

Subcritical water extraction (SCW) was used to extract oil from Chlorella pyrenoidosa. The operational factors such as reaction temperature, reaction time, and biomass loading influence the oil yield during the extraction process. In this study, response surface methodology was employed to identify the desired extraction conditions for maximum oil yield. Experiments were carried out in batch reactors as per central composite design with three independent factors including reaction temperature (170, 220, 270, 320, and 370°C), reaction time (1, 5, 10, 15, and 20 min), and biomass loading (1, 3, 5, 10, and 15%). A maximum oil yield of 12.89 wt.% was obtained at 320°C and 15 min, with 3% biomass loading. Sequential model tests showed the good fit of experimental data to the second-order quadratic model. This study opens the great potential of SCW to extract algal oil for use in algal biofuel production.

Evaluation of the energetic potential of sewage sludge by characterization of its organic composition

2016 ◽  
Vol 73 (12) ◽  
pp. 3072-3079 ◽  
Author(s):  
C. Schaum ◽  
D. Lensch ◽  
P. Cornel
Keyword(s):  
Energy Density ◽  
Sewage Sludge ◽  
Elemental Composition ◽  
Oxygen Demand ◽  
Heating Value ◽  
Organic Composition ◽  
Treatment Processes ◽  
Volatile Solids ◽  
Primary Surplus

Abstract The composition of sewage sludge and, thus, its energetic potential is influenced by wastewater and wastewater treatment processes. Higher or lower heating values (HHV or LHV) are decisive factors for the incineration/gasification/pyrolysis of sewage sludge. The HHV is analyzed with a bomb calorimeter and converted to the LHV. It is also possible to calculate the heating value via chemical oxygen demand (COD), total volatile solids (TVS), and elemental composition. Calculating the LHV via the COD provides a suitable method. In contrast, the correlation of the HHV or LHV with the TVS is limited. One prerequisite here is a constant specific energy density; this was given with the types of sewage sludge (primary, surplus/excess, and digested sludge) investigated. If the energy density is not comparable with sewage sludge, for instance with the co-substrate (bio-waste, grease, etc.), the estimation of the heating value using TVS will fail. When calculating the HHV or LHV via the elemental composition, one has to consider the validity of the coefficients of the calculation equation. Depending on the organic composition, it might be necessary to adjust the coefficients, e.g. when adding co-substrates.

scholarly journals Efficient Removal of Cr (VI) with Biochar and Optimized Parameters by Response Surface Methodology

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 889
Author(s):  
Hao Peng ◽  
Jing Guo ◽  
Hongzhi Qiu ◽  
Caiqiong Wang ◽  
Chenyu Zhang ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Reaction Time ◽  
Response Surface ◽  
Reaction Temperature ◽  
Reduction Process ◽  
Order Model ◽  
Reaction Conditions ◽  
Efficient Reduction ◽  
Experimental Parameters ◽  
Positive Effect

A highly efficient reduction process of Cr (VI) with biochar was conducted in this paper. The results showed that nearly 100% Cr (VI) was reduced at selected reaction conditions: Dosage of biochar at m (C)/m(Cr) = 3.0, reaction temperature of 90 °C, reaction time of60 min, and concentration of H2SO4 of 20 g/L. The reduction kinetics analysis demonstrated that the reduction of Cr (VI) fitted well with the pseudo-first-order model and the apparent activation energy was calculated to be 40.24 kJ/mol. Response surface methodology confirmed that all of the experimental parameters had a positive effect on the reduction of Cr (VI). The influence of each parameter on the reduction process followed the order: Dosage of biochar>concentration of H2SO4>reaction temperature >reaction time. This paper provides a versatile strategy for the treatment of wastewater containing Cr (VI) and shows a bright tomorrow for wastewater treatment.

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