scholarly journals Studies on phenol removal from wastewater with CTAB-modified bentonite supported KMnO4

2013 ◽  
Vol 3 (3) ◽  
pp. 204-216 ◽  
Author(s):  
Jing Wang ◽  
Hongzhu Ma ◽  
Jie Yu ◽  
Shanshan Wang ◽  
Wenyan He ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Photoelectron Spectroscopy ◽  
Solid Phase ◽  
Phenol Degradation ◽  
Cod Removal ◽  
Phenol Removal ◽  
Solution Ph ◽  
Modified Bentonite ◽  
X Ray ◽  
Cod Removal Efficiency

Cetyltrimethylammonium bromide (CTAB) modified bentonite supported KMnO4 (KMnO4/CTAB-bent) was prepared by solid-phase grinding method, and applied to phenol removal from wastewater. Factors affecting efficiency, such as activated temperature, initial solution pH, KMnO4/CTAB-bent dosage, phenol initial concentration and reaction temperature on degradation were investigated. It was found that pH significantly affected the degradation and chemical oxygen demand (COD) removal efficiency. The results show that over 92% degradation and 60.58% COD removal efficiency can be obtained in 30 min. The surface properties and structure of KMnO4/CTAB-bent were measured by X-ray diffraction, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller, and Fourier transform infrared spectroscopy. However, it was demonstrated that the KMnO4/CTAB-bent was deactivated quickly during phenol degradation after the second cycle, indicating that the stability of KMnO4/CTAB-bent needs to be further improved.

Phenol degradation in horizontal-flow anaerobic immobilized biomass (HAIB) reactor under mesophilic conditions

2001 ◽  
Vol 44 (4) ◽  
pp. 167-174 ◽  
Author(s):  
R. M.L. Bolaños ◽  
M. B.A. Varesche ◽  
M. Zaiat ◽  
E. Foresti
Keyword(s):  
Removal Efficiency ◽  
Phenol Degradation ◽  
Oxygen Demand ◽  
Operating Conditions ◽  
Cod Removal ◽  
Horizontal Flow ◽  
Anaerobic Sludge ◽  
Cod Removal Efficiency ◽  
Immobilized Biomass ◽  
Potential Use

A bench-scale horizontal-flow anaerobic immobilized biomass (HAIB) reactor was assayed aiming to verify its potential use for phenol degradation. The HAIB reactor consisted of a bore-silicate tube (100 cm long; 5.04 cm diameter) filled with polyurethane foam matrices containing immobilized anaerobic sludge. Before being subjected to phenol, the reactor was fed with synthetic substrate at the influent chemical oxygen demand (COD) of 1,028 mg.l−1 achieving 98% of COD removal efficiency. Thereafter, phenol as the sole carbon source was added under step-increasing concentrations from 50 to 1,200 mg.l−1. Phenol degradation was evaluated by gas chromatographic analysis of influent and effluent samples. Process monitoring included determinations of pH, volatile acids, alkalinity and COD. The HAIB reactor was operated at a constant hydraulic detention time (HDT) of 12 hours. After 33 days with 50 mg/l of phenol in the influent, the reactor achieved 98% of COD removal efficiency. Successful phenol degradation (efficiency removal of 99%) occurred for influent concentrations of 100, 300, 600, 900 and 1,200 mg.l−1 after 148, 58, 47, 29 and 7 days, respectively. The predominance of Methanosaeta-like, rods and methanogenic cocci could be observed in all the operating conditions, besides the presence of phenol oxidizing microorganisms as irregular rods. The results indicate that phenol degradation at very high rates can be accomplished in HAIB reactors containing acclimatized biomass.

scholarly journals The Effect of COD Concentration Containing Leaves Litter, Canteen and Composite Waste to the Performance of Solid Phase Microbial Fuel Cell (SMFC)

2018 ◽  
Vol 31 ◽  
pp. 02008 ◽  
Author(s):  
Ganjar Samudro ◽  
Syafrudin ◽  
Winardi Dwi Nugraha ◽  
Endro Sutrisno ◽  
Ika Bagus Priyambada ◽  
...  
Keyword(s):  
Power Density ◽  
Removal Efficiency ◽  
Food Waste ◽  
Solid Phase ◽  
Cod Removal ◽  
Process Factor ◽  
Whole Process ◽  
Cod Removal Efficiency ◽  
Efficiency Performance ◽  
The One

This research is conducted to analyze and determine the optimum of COD concentration containing leaves litter, canteen and composite waste to power density and COD removal efficiency as the indicator of SMFC performance. COD as the one of organic matter parameters perform as substrate, nutrient and dominating the whole process of SMFC. Leaves litter and canteen based food waste were obtained from TPST UNDIP in Semarang and treated in SMFC reactor. Its reactor was designed 2 liter volume and equipped by homemade graphene electrodes that were utilized at the surface of organic waste as cathode and in a half of reactor height as anode. COD concentration was initially characterized and became variations of initial COD concentration. Waste volume was maintained 2/3 of volume of reactor. Bacteria sources as the important process factor in SMFC were obtained from river sediment which contain bacteroides and exoelectrogenic bacteria. Temperature and pH were not maintained while power density and COD concentration were periodically observed and measured during 44 days. The results showed that power density up to 4 mW/m2 and COD removal efficiency performance up to 70% were reached by leaves litter, canteen and composite waste at days 11 up to days 44 days. Leaves litter contain 16,567 mg COD/l providing higher COD removal efficiency reached approximately 87.67%, more stable power density reached approximately 4.71 mW/m2, and faster optimum time in the third day than canteen based food waste and composite waste. High COD removal efficiency has not yet resulted in high power density.

Zinc immobilization by zerovalent Fe: surface chemistry and mineralogy of reaction products

2003 ◽  
Vol 67 (6) ◽  
pp. 1285-1298 ◽  
Author(s):  
R. B. Herbert
Keyword(s):  
Oxygen Consumption ◽  
Surface Chemistry ◽  
Photoelectron Spectroscopy ◽  
Solid Phase ◽  
Surface Film ◽  
Column Experiment ◽  
Green Rust ◽  
Reaction Products ◽  
Solution Ph ◽  
X Ray

AbstractIn bioreactor systems for the treatment of metal-contaminated water, pretreatment with zerovalent Fe can be exploited for oxygen consumption and H2 production. In this study, a column experiment is used to investigate the changes in surface chemistry and solid phase products that result from the reaction of a Zn-sulphate-lactate solution with zerovalent Fe filings. The results of this study indicate that zerovalent Fe is very effective in immobilizing dissolved Zn with a porewater residence time of 1.3 –3.1 days. A combination of X-ray diffractometry, X-ray photoelectron spectroscopy, and mineral equilibria calculations indicates that Zn precipitates as Zn(OH)2 and zincite at pH 9 –10. At pH ≈6, Zn primarily adsorbs to abundant ferric oxyhydroxides, although incorporation in green rust is also considered. During the course of the experiment, the surface mineralogy changes from magnetitelepidocrocite- goethite to green rust-akaganéite-goethite. The results suggest that the zerovalent Fe surface becomes passivated by a surface film of ferric oxyhydroxides, green rust and organic material, so that the rate of electron transfer and proton consuming reactions (i.e. oxygen consumption, H2 generation) declines, resulting in a decrease in solution pH.

Efficient removal of phenol from aqueous solution by the pulsed high-voltage discharge process in the presence of H2O2

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Removal Efficiency ◽  
High Voltage ◽  
Treatment Time ◽  
Phenol Degradation ◽  
Temperature Treatment ◽  
Phenol Removal ◽  
Discharge Process ◽  
Efficient Removal ◽  
Solution Ph ◽  
High Voltage Discharge

This study investigates the phenol degradation by pulsed high-voltage discharge (PHVD). The effect of solution pH, temperature, treatment time and initial phenol concentration on phenol degradation were examined. The results showed that the phenol removal efficiency was increased with the rise of pH, temperature and treatment time. The phenol removal efficiency was 48%, 46%, 42% and 34%, respectively at 10, 40, 90 and 160 ppm phenol solutions. The phenol degradation rate was increased markedly when H2O2 was added into the solution. Almost complete phenol degradation (100%) was achieved when 20-40 mM of H2O2 was added into phenol solutions of 40, 90 and 180 ppm.

scholarly journals Preparation of magnetic carbon/Fe3O4 supported zero-valent iron composites and their application in Pb(II) removal from aqueous solutions

2017 ◽  
Vol 76 (10) ◽  
pp. 2680-2689 ◽  
Author(s):  
Kaixuan Ma ◽  
Qiu Wang ◽  
Qianyun Rong ◽  
Dapeng Zhang ◽  
Shihai Cui ◽  
...  
Keyword(s):  
Removal Efficiency ◽  
Photoelectron Spectroscopy ◽  
Low Cost ◽  
Zero Valent Iron ◽  
Solution Ph ◽  
Environmental Friendliness ◽  
X Ray ◽  
Transmission Electron ◽  
Reduction Methods ◽  
Magnetic Carbon

Abstract Nanoscale zero-valent iron (NZVI) was first assembled on magnetic carbon/Fe3O4 (CM) with a combination of hydrothermal and liquid phase reduction methods. The novel NZVI@CM magnetic nanocomposites have the merits of large surface area, unique magnetic property, low cost and environmental friendliness. They can be used for Pb(II) removal in aqueous solution. The materials were characterized by using transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), X-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) adsorption. The various parameters, such as reaction time, dosage of catalyst, solution pH and acid ions concentrations were studied. The removal efficiency of Pb(II) can be obviously increased by the combination of appropriate CM and NZVI. The removal efficiency of Pb(II) is 99.7% by using 60 mg of NZVI@CM at pH 7. The kinetics study indicates that the Pb(II) removal accords to pseudo-second-order kinetics model.

scholarly journals Trimethoprim Antibiotic Adsorption from Aqueous Solution onto Eco-Friendly Zr-Metal Organic Framework Material

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7545
Author(s):  
Marwa Elkady ◽  
Kamal E. Diab ◽  
Hassan Shokry
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Removal Efficiency ◽  
Photoelectron Spectroscopy ◽  
Metal Organic Framework ◽  
Physical Nature ◽  
Polluted Water ◽  
Solution Ph ◽  
X Ray ◽  
Adsorbent Dose

The synthesis of Bio-MOF using aspartic acid as an organic linker and water as a solvent was performed to create an environmentally friendly material. The chemical composition, structure, and morphology of the synthesized zirconium Bio-MOF (MIP-202) was evaluated using X-ray diffraction (XRD), energy dispersive X-ray (EDX) spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The synthesized Bio-MOF was used as an adsorbent for trimethoprim antibiotic as pollutants from an aqueous solution under various operating parameters. The increase in the initial trimethoprim concentration from 2.5 mg/L to 20 mg/L decreased the decontamination efficiency from 77.6% to 35.9% at a solution pH of 7 with 0.5 g/L adsorbent dose after 60 min reaction time. The rise of adsorbent dose from 0.1 g/L to 1.5 g/L increased the removal efficiency from 47.7% to 87.6%. The maximum trimethoprim removal efficiency of 95% was attained at a solution pH of 11. Langmuir and pseudo-second order models described the adsorption process of trimethoprim antibiotic onto zirconium Bio-MOF and the chemo-physical nature of trimethoprim adsorption onto the synthesized zirconium Bio-MOF. Accordingly, it was evident that the prepared zirconium Bio-MOF (MIP-202) is an ecofriendly and efficient adsorbent for antibiotic decontamination from polluted water.

scholarly journals Removal of hexavalent chromium from wastewater by Cu/Fe bimetallic nanoparticles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jien Ye ◽  
Yi Wang ◽  
Qiao Xu ◽  
Hanxin Wu ◽  
Jianhao Tong ◽  
...  
Keyword(s):  
Hexavalent Chromium ◽  
Removal Efficiency ◽  
Photoelectron Spectroscopy ◽  
Bimetallic Nanoparticles ◽  
Chemical Reduction ◽  
Particle Surface ◽  
Zerovalent Iron ◽  
Order Model ◽  
X Ray ◽  
Nanoscale Zerovalent Iron

AbstractPassivation of nanoscale zerovalent iron hinders its efficiency in water treatment, and loading another catalytic metal has been found to improve the efficiency significantly. In this study, Cu/Fe bimetallic nanoparticles were prepared by liquid-phase chemical reduction for removal of hexavalent chromium (Cr(VI)) from wastewater. Synthesized bimetallic nanoparticles were characterized by transmission electron microscopy, Brunauer–Emmet–Teller isotherm, and X-ray diffraction. The results showed that Cu loading can significantly enhance the removal efficiency of Cr(VI) by 29.3% to 84.0%, and the optimal Cu loading rate was 3% (wt%). The removal efficiency decreased with increasing initial pH and Cr(VI) concentration. The removal of Cr(VI) was better fitted by pseudo-second-order model than pseudo-first-order model. Thermodynamic analysis revealed that the Cr(VI) removal was spontaneous and endothermic, and the increase of reaction temperature facilitated the process. X-ray photoelectron spectroscopy (XPS) analysis indicated that Cr(VI) was completely reduced to Cr(III) and precipitated on the particle surface as hydroxylated Cr(OH)3 and CrxFe1−x(OH)3 coprecipitation. Our work could be beneficial for the application of iron-based nanomaterials in remediation of wastewater.

scholarly journals Investigation of Heavy Metal Effects on the Anaerobic Co-Digestion Process of Waste Activated Sludge and Septic Tank Sludge

2019 ◽  
Vol 2019 ◽  
pp. 1-9
Author(s):  
Quang-Minh Nguyen ◽  
Duy-Cam Bui ◽  
Thao Phuong ◽  
Van-Huong Doan ◽  
Thi-Nham Nguyen ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Activated Sludge ◽  
Removal Efficiency ◽  
Biogas Production ◽  
Cod Removal ◽  
Septic Tank ◽  
Waste Activated Sludge ◽  
Digestion Process ◽  
Cod Removal Efficiency

The effect of copper, zinc, chromium, and lead on the anaerobic co-digestion of waste activated sludge and septic tank sludge in Hanoi was studied in the fermentation tests by investigating the substrate degradation, biogas production, and process stability at the mesophilic fermentation. The tested heavy metals were in a range of concentrations between 19 and 80 ppm. After the anaerobic tests, the TS, VS, and COD removal efficiency was 4.12%, 9.01%, and 23.78% for the Cu(II) added sample. Similarly, the efficiencies of the Zn(II) sample were 1.71%, 13.87%, and 16.1% and Cr(VI) efficiencies were 15.28%, 6.6%, and 18.65%, while the TS, VS, and COD removal efficiency of the Pb(II) added sample was recorded at 16.1%, 17.66%, and 16.03% at the concentration of 80 ppm, respectively. Therefore, the biogas yield also decreased by 36.33%, 31.64%, 31.64%, and 30.60% for Cu(II), Zn(II), Cr(VI), and Pb(II) at the concentration of 80 ppm, compared to the raw sample, respectively. These results indicated that Cu(II) had more inhibiting effect on the anaerobic digestion of the sludge mixture than Zn(II), Cr(VI), and Pb(II). The relative toxicity of these heavy metals to the co-digestion process was as follows: Cu (the most toxic) > Zn > Cr > Pb (the least toxic). The anaerobic co-digestion process was inhibited at high heavy metal concentration, which resulted in decreased removal of organic substances and produced biogas.

scholarly journals Combined treatment of hydroxypropyl guar gum in oilfield fracturing wastewater by coagulation and the UV/H2O2/ferrioxalate complexes process

2017 ◽  
Vol 77 (3) ◽  
pp. 565-575 ◽  
Author(s):  
Zhenchao Zhang
Keyword(s):  
Removal Efficiency ◽  
Guar Gum ◽  
Combined Treatment ◽  
Cod Removal ◽  
Treated Wastewater ◽  
Spectra Analysis ◽  
Hydroxypropyl Guar ◽  
Coagulation Process ◽  
Cod Removal Efficiency ◽  
Hydroxypropyl Guar Gum

Abstract Hydroxypropyl guar gum is considered to be a main component of oilfield fracturing wastewater (OFW). This work is intended to optimize the experimental conditions for the maximum oxidative degradation of hydroxypropyl guar gum by the coagulation and UV/H2O2/ferrioxalate complexes process. Optimal reaction conditions were proposed based on the chemical oxygen demand (COD) removal efficiency and UV_vis spectra analysis. The overall removal efficiency of COD reached 83.8% for a dilution ratio of raw wastewater of 1:2, pH of 4 and FeCl3 loading of 1,000 mg/L in the coagulation process; the dosage of H2O2 (30%,v/v) was 0.6% (v/v) and added in three steps, the n(H2O2)/n(Fe2+) was 2:1, n(Fe2+)/n(C2O42−) was 3:1 and pH was 4 in the UV/H2O2/ferrioxalate complexes process; pH was adjusted to 8.5–9 by NaOH and then cationic polyacrylamide (CPAM) of 2 mg/L was added in the neutralization and flocculation process. The decrease in COD during the coagulation process reduced the required H2O2 dosage and improved efficiency in the subsequent UV/H2O2/ferrioxalate complexes process. Furthermore, COD removal efficiency significantly increased by more than 13.4% with the introduction of oxalate compared with UV/Fenton. The UV_vis spectra analysis results indicated that the coagulation and UV/H2O2/ferrioxalate complexes process could efficiently remove the hydroxypropyl guar gum dissolved in OFW. An optimal combination of these parameters produced treated wastewater that met the GB8978-1996 Integrated Wastewater Discharge Standard level III emission standard.

Textile Wastewater Treatment Using Combined Process of Biological Wriggle Bed and Ozone Biological Aerated Filter

2012 ◽  
Vol 441 ◽  
pp. 589-592
Author(s):  
Zhi Min Fu ◽  
Yu Gao Zhang ◽  
Xiao Jun Wang
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Textile Wastewater ◽  
Cod Removal ◽  
Biological Aerated Filter ◽  
Combined Process ◽  
Cod Removal Efficiency ◽  
Aerated Filter ◽  
Textile Wastewater Treatment

A combined process of biological wriggle bed and ozone biological aerated filter was utilized to treat textile wastewater. Results showed that COD removal efficiency was almost 90.4%. The average effluent COD was 85.87 mg/L. The effluent colority was 64-32 times. This study indicated that the combined process is potentially useful for treating textile wastewater.

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