scholarly journals Oxidative Degradation of Hazardous Benzene Derivatives by Ferrate(VI): Effect of Initial pH, Molar Ratio and Temperature

Toxics ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 327
Author(s):  
Dian Majid ◽  
Il-Kyu Kim ◽  
Fajar Budi Laksono ◽  
Aditya Rio Prabowo
Keyword(s):  
Reaction Time ◽  
Aquatic Environment ◽  
Batch Reactor ◽  
Oxidative Degradation ◽  
Molar Ratio ◽  
Benzene Derivatives ◽  
Batch Experiments ◽  
Optimum Conditions ◽  
Initial Ph ◽  
Degradation Ability

Two of the most hazardous benzene derivatives (HBD) that have polluted the aquatic environment are bromobenzene and chlorobenzene. Ferrate can degrade various pollutants quickly and efficiently without producing harmful byproducts. This study aims to determine the ability of ferrate to degrade harmful contaminants such as bromobenzene and chlorobenzene. A series of batch experiments were carried out, including for the molar ratio, initial pH solution, and temperature. The study was conducted at an initial pH of 3.6 to 9.6, a molar ratio of 2 to 8 and a temperature of 15 to 55 °C. The study will also examine the differences in functional groups in these pollutants. As a result of the experiments, the optimum conditions to oxidize HBD in a batch reactor was found to have an initial pH of 7.0, a molar ratio of 8, and a temperature of 45 °C, with a 10 min reaction time. Ferrate has a degradation ability against chlorobenzene greater than bromobenzene. The functional cluster in pollutants also significantly affects the degradation ability of ferrate. The results of the degradation experiment showed that ferrate(VI) could effectively oxidize hazardous benzene derivatives in a solution.

Degradation of chlorpyriphos in water by advanced oxidation processes

2010 ◽  
Vol 10 (1) ◽  
pp. 1-6 ◽  
Author(s):  
R. Murillo ◽  
J. Sarasa ◽  
M. Lanao ◽  
J. L. Ovelleiro
Keyword(s):  
Reaction Time ◽  
Light Source ◽  
Advanced Oxidation Processes ◽  
Advanced Oxidation ◽  
The Other ◽  
Molar Ratio ◽  
Optimum Conditions ◽  
Oxidation Processes ◽  
Other Hand ◽  
Initial Ph

The degradation of chlorpyriphos by different advanced oxidation processes such as photo-Fenton, TiO2, TiO2/H2O2, O3 and O3/H2O2 was investigated. The photo-Fenton and TiO2 processes were optimized using a solar chamber as light source. The optimum dosages of the photo-Fenton treatment were: [H2O2]=0.01 M; [Fe3 + ]=10 mg l−1; initial pH = 3.5. With these optimum conditions total degradation was observed after 15 minutes of reaction time. The application of sunlight was also efficient as total degradation was achieved after 60 minutes. The optimum dosage using only TiO2 as catalyst was 1,000 mg l−1, obtaining the maximum degradation at 20 minutes of reaction time. On the other hand, the addition of 0.02 M of H2O2 to a lower dosage of TiO2 (10 mg l−1) provides the same degradation. The ozonation treatment achieved complete degradation at 30 minutes of reaction time. On the other hand, it was observed that the degradation was faster by adding H2O2 (H2O2/O3 molar ratio = 0.5). In this case, total degradation was observed after 20 minutes.

Optimization and statistical analysis of sono-Fenton treated wastewater of food industry using reactor by response surface method

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Vijay A. Juwar ◽  
Ajit P. Rathod
Keyword(s):  
Reaction Time ◽  
Response Surface ◽  
Food Industry ◽  
Batch Reactor ◽  
Oxygen Demand ◽  
Volume Ratio ◽  
Cod Removal ◽  
Treated Wastewater ◽  
Experimental Result ◽  
Molar Ratio

Abstract The present study deals with the treatment of complex waste (WW) treated for removal of chemical oxygen demand (COD) of the food industry by a sono-Fenton process using a batch reactor. The response surface methodology (RSM) was employed to investigate the five independent variables, such as reaction time, the molar ratio of H2O2/Fe2+, volume ratio of H2O2/WW, pH of waste, and ultrasonic density on COD removal. The experimental data was optimized. The optimization yields the conditions: Reaction time of 24 min, HP:Fe molar ratio of 2.8, HP:WW volume ratio of 1.9 ml/L, pH of 3.6 and an ultrasonic density of 1.8 W/L. The predicted value of COD was 91% and the experimental result was 90%. The composite desirability value (D) of the predicted percent of COD removal at the optimized level of variables was close to one (D = 0.991).

Oxidative Degradation of Dimethyl Phthalate (DMP) by Persulfate Catalyzed by Ag+ Combined with Microwave Irradiation

2012 ◽  
Vol 610-613 ◽  
pp. 1209-1212 ◽  
Author(s):  
De Dong Sun ◽  
Xiao Xu Yan ◽  
Wen Ping Xue
Keyword(s):  
Reaction Time ◽  
Microwave Irradiation ◽  
Rapid Method ◽  
Irradiation Time ◽  
Oxidative Degradation ◽  
Sodium Persulfate ◽  
Dimethyl Phthalate ◽  
Batch Experiments ◽  
Irradiation Effects ◽  
Mw Irradiation

The removal of dimethyl phthalate (DMP), which is a pollutant of concern in water environments, was carried out by sodium persulfate (SPS,Na2S2O8) catalyzed by Ag+combined with microwave irradiation. Effects of persulfate concentration, reaction time, microwave(MW) power and catalytic ion Ag+ on the degradation efficiency of DMP by persulfate were examined in batch experiments. The results showed that optimum Na2S2O8 concentration was 0.083mmol/L, and Ag+ concentration was 0.042 mmol/L. Increasing the MW irradiation time , persulfate concentration or Ag+ concentration might significantly accelerate DMP degradation. Catalytic ion Ag+combined with microwave irradiation was an rapid method to activate persulfate, and thus to produce SO4−• which was a powerful oxidant and could degrade DMP effectively. About 80% of DMP and 70% of COD could be degraded in 140s under the conditions of 800W MW power.

Optimization of Esterification and Transesterification Reactions for Biodiesel Production from Crude Coconut Oil Using RSM Techniques

2016 ◽  
Vol 723 ◽  
pp. 610-615 ◽  
Author(s):  
Natta Pimngern ◽  
Vittaya Punsuvon
Keyword(s):  
Fatty Acid ◽  
Reaction Time ◽  
Acid Methyl Ester ◽  
Coconut Oil ◽  
Raw Material ◽  
Biodiesel Production ◽  
Quadratic Model ◽  
Molar Ratio ◽  
Optimum Conditions ◽  
Model Equations

Crude coconut oil with high free fatty acid (FFA) content was used as a raw material to produce biodiesel. In this work, the esterification followed by transesterification of crude coconut oil with methanol is studied. The response surface methodology (RSM) with 5-level-3-factor central composite design (CCD) was applied to study the effect of different factors on the FFA content of esterification and the percentage of fatty acid methyl ester (FAME) conversion of transesterification. The FAME conversion was detected by proton magnetic resonance (1H-NMR) spectrometer. As a result, the optimum conditions for esterification were 6:1 of methanol-to-oil molar ratio, 0.75wt% of sulfuric acid (H2SO4) concentration and 90 min of reaction time. The optimum conditions for transesterification were 8.23:1 of methanol-to-oil molar ratio, 0.75wt% of sodium hydroxide (NaOH) concentration and 80 min of reaction time. Quadratic model equations were obtained describing the relationships between dependents and independent variables to minimize the FFA content and maximize the FAME conversion. Fuel properties of the crude coconut oil biodiesel were also examined followed ASTM and EN standards. The results showed that all properties met well with both standards.

Removal of ammonium as struvite using magnesite as a source of magnesium ions

2010 ◽  
Vol 5 (1) ◽  
Author(s):  
H. M. Huang ◽  
X. M. Xiao ◽  
L. P. Yang ◽  
B. Yan
Keyword(s):  
Reaction Time ◽  
Reaction Rate ◽  
Low Cost ◽  
Magnesium Ions ◽  
Batch Experiments ◽  
Optimum Conditions ◽  
Ammonium Removal ◽  
Time Required ◽  
Solid Liquid ◽  
Operation Cost

In this study, magnesite was used as a low-cost magnesium source to remove ammonium as struvite from the wastewater generated in the rare-earth elements separation process. Since the solubility of magnesite is low, before it was used it was decomposed to magnesia which has a higher reaction rate than magnesite. To optimize its usage, the optimum temperature of decomposition of magnesite and the time required for the process were determined by batch experiments to be 700 °C and 1.5 h, respectively. Besides, batch experiments using the residues of magnesite decomposed under optimum conditions were undertaken to investigate the effects of solid (magnesite)/liquid (wastewater) ratio and reaction time on ammonium removal as struvite. Results indicated that for the solid/liquid ratios tested and for a reaction time of 6 h, phosphorus concentrations fell steeply from the initial 9105 mg/L to a range of 198.8–29.8 mg/L, and ammonium concentrations from the initial 5287 mg/L to 540–520 mg/L. An economic analysis conducted indicated that the operation cost of the struvite process could be reduced by about 34% using decomposed magnesite instead of pure MgCl2.

scholarly journals Optimization of Biodiesel Production Using Nanomagnetic CaO-Based Catalysts with Subcritical Methanol Transesterification of Rubber Seed Oil

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 230 ◽  
Author(s):  
Veronica Winoto ◽  
Nuttawan Yoswathana
Keyword(s):  
Reaction Time ◽  
Seed Oil ◽  
Acid Methyl Ester ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Catalyst Loading ◽  
Optimum Conditions ◽  
Rubber Seed Oil ◽  
Box Behnken Design ◽  
Rubber Seed

The molar ratio of methanol to rubber seed oil (RSO), catalyst loading, and the reaction time of RSO biodiesel production were optimized in this work. The response surface methodology, using the Box–Behnken design, was analyzed to determine the optimum fatty acid methyl ester (FAME) yield. The performance of various nanomagnetic CaO-based catalysts—KF/CaO-Fe3O4, KF/CaO-Fe3O4-Li (Li additives), and KF/CaO-Fe3O4-Al (Al additives)—were compared. Rubber seed biodiesel was produced via the transesterification process under subcritical methanol conditions with nanomagnetic catalysts. The experimental results indicated that the KF/CaO-Fe3O4-Al nanomagnetic catalyst produced the highest FAME yield of 86.79%. The optimum conditions were a 28:1 molar ratio of methanol to RSO, 1.5 wt % catalyst, and 49 min reaction time. Al additives of KF/CaO-Fe3O4 nanomagnetic catalyst enhanced FAME yield without Al up to 18.17% and shortened the reaction time by up to 11 min.

scholarly journals Yellow 2G dye degradation by electro-Fenton process using steel electrode as catalysis and its phytotoxicity effect

2020 ◽  
Author(s):  
Amel Benhadji ◽  
Mourad Taleb Ahmed
Keyword(s):  
Dye Degradation ◽  
Batch Reactor ◽  
Reaction Times ◽  
Fenton Process ◽  
Optimum Conditions ◽  
Germination Test ◽  
Solution Ph ◽  
Steel Electrode ◽  
Initial Ph ◽  
Current Densities

Abstract The heterogeneous electro-Fenton process degradation of Yellow 2G from wastewater was studied using a batch reactor. The COD of the wastewater used in treatment experiments was 163 mg O2·L−1 and the BOD5 was 17 mg O2·L−1 (hardly biodegradable). The treatment of the wastewater at different current densities (2.5 mA·cm−2–12.5 mA·cm−2), solution pH (3 and 6.6), reaction times (5–25 min), electrolyte nature (NaCl, Na2SO4) and electrolyte concentrations (0.15 g·L−1–1 g·L−1) was investigated. According to the results, the heterogeneous electro-Fenton process was suitable for the decolorization of wastewater containing Yellow 2G. The optimum conditions were current density of 12.5 mA·cm−2, initial pH of the wastewater neutral, 25 min of electrolysis treatment using an additive steel electrode as a source of catalysis and in the presence of 1 g NaCl·L−1. We obtained easily biodegradable water with a mineralization rate equal to 85% and non-toxicity confirmed by the pea grain germination test.

Catalytic Synthesis of Butyraldehyde Glycol Acetal with H4SiW12O40/MCM-48

2012 ◽  
Vol 531 ◽  
pp. 312-315 ◽  
Author(s):  
Ming Bo Xu ◽  
Jie Yang ◽  
Yong Kui Huang ◽  
Shui Jin Yang
Keyword(s):  
Reaction Time ◽  
Molecular Sieve ◽  
Catalytic Synthesis ◽  
Molar Ratio ◽  
Impregnation Method ◽  
Mass Ratio ◽  
Optimum Conditions ◽  
Environmental Friendly ◽  
Ft Ir ◽  
Catalyst Dosage

A novel environmental friendly catalyst，H4SiW12O40/MCM-48, was prepared by impregnation method. The catalysts were characterized by means of XRD and FT-IR. The synthesis of butyraldehyde glycol acetal catalyzed by H4SiW12O40/MCM-48 was studied with butyraldehyde and glycol as reactants. H4SiW12O40/MCM-48 was an excellent catalyst for the synthesizing butyraldehyde glycol acetal and Keggin structure of H4SiW12O40 kept unchanged after being impregnated on surface of the molecular sieve support. Effects of n(butyraldehyde)∶n(glycol), catalyst dosage, cyclohexane(water-stripped reagent ) and reaction time on yields of the product were investigated. The optimum conditions had been found, that is, molar ratio of butyraldehyde to glycol is1:1.4，mass ratio of catalyst used to the reactants is 0.4% and reaction time is 45 min. Under these conditions, the yield of butyraldehyde glycol acetal can reach 73.3%.

scholarly journals Combination of novel coalescing oil water separator and electrocoagulation technique for treatment of petroleum compound contaminated groundwater

2017 ◽  
Vol 76 (1) ◽  
pp. 57-67
Author(s):  
Sepideh Oladzad ◽  
Narges Fallah ◽  
Bahram Nasernejad
Keyword(s):  
Reaction Time ◽  
Current Density ◽  
Aeration Rate ◽  
Contaminated Groundwater ◽  
Second Phase ◽  
Optimum Conditions ◽  
Water Separator ◽  
Initial Ph ◽  
Oil Water ◽  
Sedimentation Time

In the present study a combination of a novel coalescing oil water separator (COWS) and electrocoagulation (EC) technique was used for treatment of petroleum product contaminated groundwater. In the first phase, COWS was used as the primary treatment. Two different types of coalescing media and two levels of flow rates were examined in order to find the optimum conditions. The effluent of COWS was collected in optimum conditions and was treated using an EC process in the second phase of the research. In this phase, preliminary experiments were conducted in order to investigate the effect of EC reaction time and sedimentation time on chemical oxygen demand (COD) removal efficiency. Best conditions for EC reaction time and sedimentation time were obtained to be 5 min and 30 min, respectively. Response surface methodology was applied to evaluate the effect of initial pH, current density and aeration rate on settling velocity (Vs) and effluent COD. The optimum conditions, for achieving maximum values of Vs as well as the values of effluent COD, in the range of results were obtained at conditions of 7, 34 mA·cm−2 and 1.5 L·min−1 for initial pH, current density and aeration rate, respectively.

scholarly journals Sorption of Sr-85 and Am-241 from liquid radioactive wastes by alginate beads

Nukleonika ◽  
2015 ◽  
Vol 60 (4) ◽  
pp. 927-931 ◽  
Author(s):  
Agata Oszczak ◽  
Leon Fuks
Keyword(s):  
Contact Time ◽  
Adsorption Process ◽  
Decontamination Factor ◽  
Alginate Beads ◽  
Radioactive Wastes ◽  
Batch Experiments ◽  
Optimum Conditions ◽  
Liquid Radioactive Wastes ◽  
Initial Aqueous Solution ◽  
Initial Ph

Abstract The paper reports the adsorption of strontium(II) and americium(III) from aqueous solutions onto calcium alginate (CaA), barium alginate (BaA) and strontium alginate (SrA) beads. Adsorption process was studied in batch experiments as a function of the initial pH of the solution and the contact time. All sorbents were examined by the termogravimetric analysis (TG). Laboratory obtained spherical beads of CaA, BaA and SrA seem to be good metal sorbents from liquid radioactive wastes. A contact time of about 4 h and neutral pH of the initial aqueous solution have been proposed to be optimum conditions for Sr-85 and Am-241 removal from the contaminated solutions using alginate sorbents. Laboratory obtained beads of CaA, BaA and SrA are characterized by the decontamination factor (DF) equal to 85% for Sr(II) and 90% for Am(III).

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