scholarly journals Biological Treatment of Wastewater from Pyrolysis Plant: Effect of Organics Concentration, pH and Temperature

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 336
Author(s):  
Luca Di Palma ◽  
Irene Bavasso ◽  
Mauro Capocelli ◽  
Paolo De Filippis ◽  
Vincenzo Piemonte
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Biological Treatment ◽  
Order Kinetic ◽  
Batch Mode ◽  
Mean Values ◽  
Wood Pyrolysis ◽  
Toc Removal ◽  
Order Kinetic Model ◽  
Different Temperatures

The biological treatment of the aqueous residue produced during poplar wood pyrolysis was investigated. The biological treatment experiments were carried out at two different pH conditions (controlled at 7, uncontrolled) in batch mode at three different temperatures (15 °C, 25 °C and 30 °C) and initial total organic carbon of the water ranging from 800 mg/L to 2800 mg/L. Results show that a substantial removal of organic carbon could be achieved in aerobic conditions after biomass acclimation. After 72 h of treatment, total organic carbon (TOC) removal mean values of 49.47% and 53.03% were observed at 30 °C for solution at 1400 and 2000 mg/L initial TOC, respectively. In the case of 1400 mg/L, a further mineralization (61.80%) was achieved during 144 h of treatment, by using a two-step process. A kinetic study of the process was also made, showing that organics mineralization followed a first-order kinetic model.

scholarly journals Thermally activated persulfate treatment and mineralization of a recalcitrant high TDS petrochemical wastewater

2017 ◽  
Vol 19 (2) ◽  
pp. 72-77 ◽  
Author(s):  
Sahand Jorfi ◽  
Sudabeh Pourfadakari ◽  
Mehdi Ahmadi ◽  
Hamideh Akbari
Keyword(s):  
Ph Value ◽  
Cod Removal ◽  
Order Kinetic ◽  
Operational Parameters ◽  
Batch Mode ◽  
Thermally Activated ◽  
Toc Removal ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Activated Persulfate

Abstract Thermally activated persulfate efficiency for the treatment of a recalcitrant high TDS wastewater was investigated. The specific character of studied wastewater was high TDS content of around 23820 mg/L and BOD5/COD ratio of 0.07. Effective operational parameters including initial pH values of 3–9, reaction temperature of 40–80°C and persulfate concentrations of 0.5–5 g/L for COD removal were investigated in batch mode experiments. Removal efficiency was pH and temperature dependent. The COD and TOC removal of 94.3% and 82.8% were obtained at persulfate concentration of 4 g/L, initial pH value of 5 and temperature of 70°C after 180 min for initial COD concentration of 1410 mg/L. The pseudo first-order kinetic model was best fitted with COD removal (R2 = 0.94).

scholarly journals Factors influencing the adsorption and photocatalysis of direct red 80 in the presence of a TiO2: Equilibrium and kinetics modeling

2021 ◽  
pp. 174751982198996
Author(s):  
Moussa Abbas
Keyword(s):  
Elimination Rate ◽  
Threshold Value ◽  
Heterogeneous Photocatalysis ◽  
Order Kinetic ◽  
Batch Mode ◽  
Adsorption Capacities ◽  
Initial Ph ◽  
Equilibrium And Kinetics ◽  
Order Kinetic Model ◽  
Charge Point

Among the different photocatalysts, TiO2 ( Eg = 3.1 eV, zero charge point (pHpzc = 6.3), and surface = 55 m2/g) is currently the most efficient and the most studied semiconductor due to its strong photocatalytic activity, non-toxicity, and chemical stability. The elimination of DR-80 on TiO2 is studied by adsorption in batch mode and by application of heterogeneous photocatalysis onto TiO2 under UV irradiation. The effects of contact time (0–60 min), initial pH (3–11), dose of the adsorbent (0.5–3 g L−1), and DR-80 concentration (40–60 mg L−1) on the adsorption of DR-80 by TiO2 are studied for optimization of these parameters. The kinetic parameters, rate constants, and equilibrium adsorption capacities are calculated and discussed for each applied theoretical model. The adsorption of DR-80 is well described by the pseudo-first-order kinetic model. The fitting of the adsorption isotherms shows that the models of Langmuir and Temkin offering a better fit and an adsorption 64.102 mg/g at 25 °C of DR-80 are eliminated. The results showed that the photocatalytic efficiency strongly depends on the pH while the initial rate of photodegradation is proportional to the catalyst dose, and becomes almost constant above a threshold value. It was found that the photodegradation is favored at low DR-80 concentrations in accordance with the Langmuir–Hinshelwood model with the constants Kad = 6.5274 L/mg and KL–H = 0.17818 mg L−1 min. However, the adsorption is improved for high DR-80 concentrations. It is found that the degradation depends on both the temperature and the pH with a high elimination rate at high temperature. The photocatalyst TiO2 has a better activity for the degradation of DR-80, compared to some commercial catalysts that have been described in the literature.

Biodecolorization of Basic Violet 03 Using Biochar Derived from Agricultural Wastes: Isotherm and Kinetics

2020 ◽  
Vol 14 (3) ◽  
pp. 316-326 ◽  
Author(s):  
Josephraj Jegan ◽  
Saravanan Praveen ◽  
Thillainayagam Bhagavathi Pushpa ◽  
Ravindran Gokulan
Keyword(s):  
Binding Capacity ◽  
Maximum Yield ◽  
Agricultural Wastes ◽  
Order Kinetic ◽  
Optimum Conditions ◽  
Batch Mode ◽  
Before And After ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Best Fit

In the present study, bioremediation of Basic Violet 03 is examined using biochar derived from agricultural wastes. The pyrolytic studies revealed that ideal temperature for maximum yield of biochar derived from Coconut Shell (CSB), Ground nut Shell (GnSB) and Rice Husk (RHB) was obtained as 400 °C, 350 °C and 300 °C respectively. Further from the batch mode of operations, it was concluded that the optimum conditions of biochar dose, pH, temperature and initial concentration are 4 g/L, 8, 40 °C and 75 mg/L with a maximum uptake of 15.79 mg/g, 17.28 mg/g, and 12.64 mg/g for CSB, GnSB and RHB. The adsorption isotherm studies concluded that the three-parameter Sips model was obtained to be the best fit with a maximum correlation coefficient (R2) of 0.9937, 0.9935 and 0.9965. The pseudo second order kinetic model was found to well represent the experimental kinetic data. The characterization results of biochar through SEM, EDX and FTIR revealed that there was a strong binding capacity of adsorbent was observed before and after adsorption process. The promising results concluded that biochar derived from agricultural wastes can potentially be utilized for the removal of cationic dyes.

Photocatalytic Degradation of Indigo Carmine Dye Using Hydrothermally Synthesized Anatase TiO2 Nanotubes under Ultraviolet Light Emitting Diode Irradiation

2016 ◽  
Vol 855 ◽  
pp. 45-57 ◽  
Author(s):  
Kalithasan Natarajan ◽  
Rukshana I. Kureshy ◽  
Hari C. Bajaj ◽  
Rajesh J. Tayade
Keyword(s):  
Photocatalytic Degradation ◽  
Band Gap ◽  
Organic Dyes ◽  
Light Emitting Diode ◽  
Indigo Carmine ◽  
Order Kinetic ◽  
Light Emitting ◽  
Order Kinetic Model ◽  
Different Temperatures ◽  
Adsorption Desorption

Anatase TiO2 nanotubes (ATNT) was synthesised by hydrothermal method using anatase TiO2 nanoparticles (AT) as precursor and calcined at two different temperatures (250 & 450 °C) for 2 h. The AT and synthesized ATNT photocatalysts were characterized by X-ray diffraction, transmission electron microscopy, N2 adsorption-desorption measurements, UV-vis diffuse reflectance and Fourier Transform Infra-red spectroscopy techniques for their structural, textural and electronic properties. The photocatalytic degradation of Indigo carmine (IC) dye aqueous solution has carried out using ATNT-250 and ATNT-450 photocatalysts under UVLED irradiation. The kinetic analysis has also revealed that the degradation of IC dye solution follows first order kinetic model. The overall study demonstrates the appropriate band gap of the photocatalysts used and the suitable irradiation source which could accelerate the rate of photocatalytic degradation. The band gap of the synthesised ATNT is not much affected due to the change in morphology from nanoparticle to nanotube. The results demonstrated that the irradiation of UV-LED could be utilised for the degradation of organic dyes

scholarly journals Adsorption of tricresyl phosphate onto graphene nanomaterials from aqueous solution

2017 ◽  
Vol 76 (6) ◽  
pp. 1565-1573 ◽  
Author(s):  
Jun Liu ◽  
Siying Xia ◽  
Xiaomeng Lü ◽  
Hongxiang Shen
Keyword(s):  
Experimental Data ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Tricresyl Phosphate ◽  
Batch Mode ◽  
Order Kinetic Model ◽  
Endothermic Process ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Increasing Temperature

Phosphorus flame retardant tricresyl phosphate (TCP) adsorption on graphene nanomaterials from aqueous solutions was explored using batch and column modes. Comparative studies were performed regarding the kinetics and equilibrium of TCP adsorption on graphene oxide (GO) and graphene (G) in batch mode. The adsorption kinetics exhibited a rapid TCP uptake, and experimental data were well described by the pseudo-second-order kinetic model. Adsorption isotherm data of TCP on the two adsorbents displayed an improved TCP removal performance with increasing temperature at pH 5, while experimental data were well described by the Langmuir isotherm model with a maximum adsorption capacity of 87.7 mg·g−1 for G, and 30.7 mg·g−1 for GO) at 303 K. The thermodynamic parameters show that the adsorption reaction is a spontaneous and endothermic process. In addition, dynamic adsorption of TCP in a fixed G column confirmed a faster approach to breakthrough at high flow rate, high influent TCP concentration, and low filling height of adsorbent. Breakthrough data were successfully described by the Thomas and Yoon-Nelson models.

scholarly journals Pesticide production wastewater treatment by Electro-Fenton using Taguchi experimental design

2021 ◽  
Author(s):  
Thanh Luu Pham ◽  
Faten Boujelbane ◽  
Hiep Nghia Bui ◽  
Hieu Trung Nguyen ◽  
Xuan-Thanh Bui ◽  
...  
Keyword(s):  
Kinetic Model ◽  
Density Functional ◽  
Reaction Kinetic ◽  
Polynomial Regression ◽  
Treated Wastewater ◽  
Order Kinetic ◽  
Functional Theory ◽  
First Order ◽  
Toc Removal ◽  
Order Kinetic Model

Abstract In this study, the electro – Fenton (EF) method was applied to remove total organic carbon (TOC) from the pesticide production wastewater containing tricyclazole (TC). Statistical Taguchi method was used to optimize the treatment performance. Analysis of variance (ANOVA) indicated that the polynomial regression model fitted experimental data with R2 of 0.969. The optimal conditions for eliminating 75.4% TOC and 93.7% TC, were 0.2 mM of Fe2+, 990 mg/L of Na2SO4, 180 min of reaction time at pH 3 with 2.22 mA/cm2 of current density. The removal of TC present in the wastewater followed the first-order reaction kinetic model (R2 = 0.993); while that was the second-order kinetic model in the case of the TOC removal (R2 = 0.903). In addition, the experimental results and theory approaches (density functional theory and natural bond orbital calculations) also showed that the C-N bond breaking and nitrate ions cleavage ammonia. Acute toxicity of the pesticide wastewater after treatment (PWAT) on microcrustacean showed that the treated wastewater still exhibited high toxicity against D. magna, with LC50 values of 3.84%, 2.68%, 2.05%, and 1.78% at 24 h, 48 h, 72 h, and 96 h, respectively.

Lead Adsorption from Aqueous Solution Using Manganese Oxides Recovered from Spent Alkaline Batteries

2020 ◽  
Vol 46 (3) ◽  
pp. 206-212
Author(s):  
Franco Medici ◽  
María Silvina Patterer ◽  
Miguel Andrés Peluso ◽  
Jorge Enrique Sambeth
Keyword(s):  
Manganese Oxides ◽  
Kinetic Studies ◽  
Xrd Analysis ◽  
Maximum Adsorption Capacity ◽  
Order Kinetic ◽  
Lead Adsorption ◽  
Alkaline Batteries ◽  
Batch Tests ◽  
Order Kinetic Model ◽  
Different Temperatures

Lead is a highly toxic element and can cause serious illnesses, as a consequence of this, stringent limits have been set for this element, especially regarding drinking water. In this paper, the potential of manganese oxides (MnOx) as adsorbents for the removal of lead (as Pb II) from synthetically contaminated water was investigated. These oxides were recovered from alkaline batteries by a bio-hydrometallurgical process through potassium permanganate (KMnO4) precipitation. The MnOx was characterized by Scanning Electronic Microscopy (SEM), Energy Dispersive Spectroscopy (SEM-EDS) and X Ray Diffraction (XRD) analysis. The surface area of the material was determined using the N2 isotherm by the BET method. Batch tests were performed on untreated manganese oxides at different temperatures (10, 25 and 40°C), utilizing initial adsorbate concentration ranging from 5 to 100 mg L-1 and contact times between 1 minute and 30 minutes. The Langmuir isotherm provided the best correlation for the adsorption process, with a maximum adsorption capacity of 9.51 (mg g–1) at 10 °C. Kinetic studies revealed that the lead adsorption onto MnOx followed a pseudo-second order kinetic model, while the thermodynamic study has highlighted that the adsorption of lead is exothermic and spontaneous.

scholarly journals Adsorption of an anionic dye (Congo red) from aqueous solutions by pine bark

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Khaoula Litefti ◽  
M. Sonia Freire ◽  
Mostafa Stitou ◽  
Julia González-Álvarez
Keyword(s):  
Congo Red ◽  
Low Cost ◽  
Pine Bark ◽  
Point Of Zero Charge ◽  
Order Kinetic ◽  
Batch Mode ◽  
Adsorbent Dosage ◽  
Equilibrium Data ◽  
Order Kinetic Model ◽  
Cr Concentration

Abstract Pinus pinaster bark, an abundant by-product from the timber industry, has been studied as a potential low-cost adsorbent for the removal of Congo red (CR) dye from wastewaters. Surface morphological and physico-chemical characteristics of pine bark were analysed using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), determination of the point of zero charge (pHPZC) and elemental analysis. Assays were performed to determine the wavelength for the maximum absorbance and the stability with time of CR solutions depending on concentration and/or pH, which resulted to be a very significant parameter. Adsorption studies were conducted on batch mode to study the effect of contact time (till 7 days), pH (2–9), adsorbent dosage (1–10 g L−1) and temperature (25–60 °C). The bark adsorption capacity at equilibrium varied between 0.3 and 1.6 mg g−1 and the equilibrium adsorption percentage between 23.4 and 100% depending on adsorbent dosage, temperature and pH at an initial CR concentration of 5 mg L−1. Kinetic data for the removal of CR by pine bark were best fitted by the pseudo-second-order kinetic model. The equilibrium data fitted well with the Freundlich model. Thermodynamic analysis indicated that the adsorption process is exothermic and spontaneous.

Esterification of chitosan with L-alanine and a study on their effect in removing the heavy metals and total organic carbon (TOC) from wastewater

2016 ◽  
Vol 88 (6) ◽  
pp. 595-604 ◽  
Author(s):  
Hassan H. H. Hefni ◽  
Mohammed Nagy ◽  
Mohammed M. Azab ◽  
Mohammed H. M. Hussein
Keyword(s):  
Heavy Metals ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Adsorption Capacity ◽  
Elemental Analysis ◽  
Maximum Adsorption Capacity ◽  
X Ray Diffraction ◽  
Batch Mode ◽  
Ionic Bonds ◽  
Total Maximum

AbstractIn this work, chitosan was modified by the esterification with L-alanine in the presence of H2SO4 as a catalyst to increase the number of amino groups with the aim of increasing the adsorption efficiency. Chitosan (CS) and chitosan-O-alanine (CS-Aln) were characterized and investigated by elemental analysis, Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). The results obtained from elemental analysis and IR indicated the presence of sulfuric acid after neutralization as a crosslinker between CS-Aln chains. Also CS-Aln is more amorphous than CS due to the ionic bonds of crosslinker. The removal of three heavy metals (Mn2+, Pb2+ and Al3+) and total organic carbon (TOC) from wastewater by CS and CS-Aln in the batch mode has been studied at different adsorbent dosages, temperatures and contact times. The maximum metal ions removal efficiency using CS achieved 99.6%, 99.1% and 98.9%, respectively, while by using CS-Aln 95.3%, 99.3% and 98.9% were achieved. However, the maximum adsorption capacity of TOC by CS achieved 50 mg/g and 89 mg/g by CS-Aln. The total maximum adsorption capacity of CS-Aln is higher than CS.

DM Water Plant Sedimentation as a Cheap and Waste Source of Catalyst for Biodiesel Production

2016 ◽  
Vol 14 (1) ◽  
pp. 113-124 ◽  
Author(s):  
Gholamreza Moradi ◽  
Majid Mohadesi ◽  
Shokoufe Hosseini ◽  
Yegane Davoodbeygi ◽  
Ramin Moradi
Keyword(s):  
Catalyst Concentration ◽  
Design Method ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Order Kinetic ◽  
Water Plant ◽  
Order Kinetic Model ◽  
Different Temperatures ◽  
Effects Of Temperature ◽  
Good Agreement

AbstractTransesterification reaction was performed in the presence of soybean oil, methanol, and Demineralized water plant sedimentation catalyst at 60°C for 8 h in this study. Central composite design method was used to study the effect of catalyst concentration and methanol to oil molar ratio on purity and yield of produced biodiesel. The results showed catalyst concentration of 9.08 wt% and methanol to oil molar ratio of 22.49 as the optimum condition in which the values of purity and yield of the produced biodiesel in the second-order models were 99.89% and 81.83%, respectively. Experiments are in good agreement with the mentioned values as corresponded values are 99.95% and 86.68%, respectively. The catalyst was reused five times and XRF analyses showed a reduction in content of available CaO in catalyst after further usages, because of CaO extraction by methanol. Also for kinetics investigation, effects of temperature and time of the reaction on the produced biodiesel conversion at optimal condition were investigated. Rate constant at different temperatures and then activation energy were determined. Results showed high accuracy of first order kinetic model. Mean relative error of experimental data for the presented model was 2.42%.

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