Global NEST Journal

ISSN:

Print ISSN: 1790-7632

Electronic ISSN: 2241-777X

Volume 18 - 2016

Articles

Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) applied to the chemical characterization of Diesel soot

Tapia A., Salgado S., Sánchez-Valdepeñas J., Martín P., Rodríguez J. and Cabañas B., Pages:453-462

DOI:

https://doi.org/10.30955/gnj.001692

Paper Topic:

E2KW 2013

Issue:

Issue 3

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Abstract

In this work, diesel soot has been characterized chemically using a diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) technique. Diesel soot samples were generated under combustion conditions reproducing the typical urban operating mode of a diesel engine. Initial experiments performed to ensure the repeatability of the Drifts analysis and the sample preparation method showed that the standard deviations were always lower than 20% for the DRIFTS analysis itself, and lower than 25% when sample preparation was included. This is of special interest as regards application of the DRIFTS technique for quantitative analysis. The functional groups on the soot surface were identified on the basis of the infrared bands observed in the spectra at room temperature, indicating that the diesel soot analyzed comprises a mixture of aromatic hydrocarbons, carboxylic compounds, hydroxyl species, ether groups, and methylene and methyl groups. Analyses were also carried out at different temperatures in the interval of 298-858 K in order to analyze the thermal stability of the functional groups, with carbonyl groups, lactones and ethers appearing to be the most thermally stable compounds.

The effect of Iron Ion on Removal Efficiency of Dissolved Organic Carbon (DOC) Using UV/TiO2

Mansouri, F Ranandeh Kalankesh, L Hasankhani, H , Pages:392-401

DOI:

https://doi.org/10.30955/gnj.001954

Paper Topic:

Water and Wastewater Treatment

Issue:

Issue 2

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Abstract

Most of water sources throughout the world contain natural organic matter (NOM), which is the best description as a complex mixture of organic compounds. The effect of iron ion on removal efficiency of dissolved organic carbon (DOC) using UV/TiO₂ photo catalytic oxidation (TiO₂) was examined. In this quasi-experimental study, the different variables such as pH value, contact time, various concentrations of TiO₂, FeCl₂ on the removal efficiency of DOC by the UV/TiO₂ on raw water of Zayandehroud in Isfahan were studied. The results were analyzed by using Pearson correlation coefficient test and SPSS software. Removal efficiency DOC improved as the amount of catalyst was increased. Maximum removal efficiency was achieved during acidic conditions (pH=3) within 60 minutes of contact time. The removal efficiency of DOC by the UV/TiO₂ decreased with increase of contact time. The presence of iron ions increased the rate of DOC removal by the UV/TiO₂. Removal efficiency of dissolved organic carbon increased when ionic strength and initial concentration of Ferric Chloride was increased. Also, by adding particles of Ferric Chloride, Removal of dissolved organic carbon increased to 98% in comparison with absence of iron ion (78%).

The removal of oxytetracycline (OTC) by potassium ferrate (VI) in aquatic environment

Zeng FC Liu YB Wang HY, Pages:381-391

DOI:

https://doi.org/10.30955/gnj.001951

Paper Topic:

Water and Wastewater Treatment

Issue:

Issue 2

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Abstract

The treatment of oxytetracycline (OTC) in test solutions by ferrate (VI) was investigated aiming to propose the effects of pH, concentration of co-existing ions and humic acid on the OTC removal. Ferrate (VI) can remove 97% OTC (from 1000 µg·l^-1) in 30 minutes under the optimal conditions with solution pH of 7 and ferrate (VI) dosage of 20:1 as a molar ratio of ferrate (VI)/OTC. The effects of co-existing ions (0.005 mol·l^-1 and 0.02 mol·l^-1) and humic acid (0.1~50 mg·l^-1) on the OTC removal were investigated for the optimal operating conditions. The results showed that Ca²⁺, CO₃^2-, PO₄^3-could inhibit the OTC degradation and its removal rate decreased from 79, 29, 29% to 70, 19, 19%, for the ion concentration increased from 0.005
mol·l^-1 to 0.02 mol·l^-1. Mg²⁺ and HCO₃^- could restrain the reaction carried out at 0.02 mol·l^-1 and the removal rate was only 59%, 62%. Al³⁺could increase the removal rate which reach to 100%. Humic acid with concentrations of greater than 10 mg·l^-1 could notably inhibit the OTC removal. Regression analysis indicated good fit of the experimental date to the developed model with coefficient of determination (R²) value of 0.9991 and the adjusted R² value of 0.9978.

Chemical and physical preparation of activated carbon using Raw bagasse for cationic dye adsorption

Taha N.A., Abdelhafez S.E. and El-Maghraby A., Pages:402-415

DOI:

https://doi.org/10.30955/gnj.001916

Paper Topic:

Water and Wastewater Treatment

Issue:

Issue 2

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Abstract

Agriculture wastes like sugarcane bagasse are available in large quantities in Egypt. Various adsorbents from natural materials, industrial waste materials, agricultural by-products, and biomass based activated carbon can be used in the removal of various dyes. Raw Bagasse pith (RBP) was used to prepare activated carbon (AC) using phosphoric acid (H₃PO₄) as a chemical activating agent. C The raw BP and the synthesized adsorbent were characterized by Fourier transform infrared (FTIR) spectroscopy and scanning electron microscope (SEM). The effectiveness of AC prepared in adsorption of methylene blue (MB) has been studied as a function of adsorbent type, initial dye concentration and contact time. The effects of the initial dye concentration and contact time were evaluated. Adsorption isotherm models - Langmuir, Freundlich and Temkin were used to simulate the equilibrium data. Langmuir equation was found to have the highest value of R² compared with other models. Furthermore, it was found that sugarcane bagasse have a high adsorptive capacity towards MB.

Decolarization of methylene blue and methyl orange with Ag doped TiO2 under UV-A and UV-Visible conditions: process optimization by response surface method and toxicity evaluation

Deniz İzlen Çifçi, Pages:371-380

DOI:

https://doi.org/10.30955/gnj.001899

Paper Topic:

Water and Wastewater Treatment

Issue:

Issue 2

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Abstract

MB decolarization with pure TiO₂ and Ag doped TiO₂ based photocatalytic system were investigated under UV-A and UV-Visible conditions. Different ratios of Ag were used as metal dopant. 1% Ag-TiO₂ increased the decolorization efficiencies of MB and MO dyes, also the k_app constant enhanced under UV-A and UV-Visible conditions. A central composite analysis showed the effect of initial dye concentration, pH, Ag-TiO₂ concentration and the reaction time of photocatalytic process under UV-A irridation in both dyes. The photocatalytic degradation pathways of both dyes by Ag doped TiO₂ catalyst were obtained in this study. According to these results, the application of Ag-TiO₂ catalyst are proved to be more effective than pure TiO₂ catalyst for both MB and MO removal. The toxicity test of Daphnia Magna shows that non toxic wastewater discharge to the receiving environment could be possible with photocatalytic degration by Ag-TiO₂ catalyst.

Molecular weight distribution of pollutants in leachate from full scale landfill site

Yaman F.B., Çakmakci M., Campagna M. and Özkaya B. , Pages:360-370

DOI:

https://doi.org/10.30955/gnj.001898

Paper Topic:

Water and Wastewater Treatment

Issue:

Issue 2

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Abstract

The main objective of this study was to investigate the differences between the main pollutants in young and intermediate age landfill leachate in terms of molecular weight distribution (MWD). Parameters of chemical oxygen demand (COD), five day - biochemical oxygen demand (BOD₅), ultraviolet-visible spectrophotometry (UV-VIS spectrum), total kjehldahl nitrogen (TKN), ammonia nitrogen (NH₄-N) and colour were fractioned by membranes with the nominal pore size of 1µm, 0.05 µm, 100 kDa, 50 kDa, 10 kDa, 1 kDa and 0.5 kDa. According to the MWD results appropriate treatment technology could be choosen easily. According to the MWD results the ratio of soluble fractions (< 0.5 kDa) to total COD was 34% in young leachate (YL), whereas low molecular weight (MW) fractions were dominant in intermediate leachate (IL) having this ratio of 71%. Presence of lower MW compounds in IL was also confirmed with UV-VIS absorbance spectra and its spectrum was higher than the YL. According to the specific ultraviolet absorption (SUVA) values, the organic contents of all of these processes were hydrophilic. TKN and NH₄-N analysis showed that in IL all the nitrogen present is in ammoniacal form, instead in YL there is still the presence of organic nitrogen. Furthermore more than half of the TKN was less than 0.5 kDa while 6 % and 16 % TKN found in wastewater from IL and YL was higher than 1 µm respectively. The observations of this study may provide useful criteria to choose a suitable landfill leachate treatment processes.

Comparison of treatment efficiency and molecular weight distribution of membrane concentrate from textile wastewater

Yaman F.B., Çakmakci M., Karadag D., Yetilmezsoy K., Ozkaya B., Turkay H., Genc T., Pages:348-359

DOI:

https://doi.org/10.30955/gnj.001886

Paper Topic:

Water and Wastewater Treatment

Issue:

Issue 2

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Abstract

This study investigated the treatability and changes in molecular weight distributions (MWD) of membrane concentrate. Nanofiltration (NF) concentrate from textile wastewater was subjected sole anaerobic treatment (R1) and pre-ozonation (R2) plus anaerobic treatment. BOD₅, COD and TOC, color, sulphate and specific ultraviolet absorbtion at 254 nm (SUVA₂₅₄) were analysed. Pre-ozonation improved the biodegradability of the membrane concentrate. The low molecular weight (LMW) organics was an important reason for the overall biodegradability enhancement of the membrane concentrate. Color was caused mainly by matters with higher than MWD of 10 kDa and 80% of HMW organics were removed during anaerobic treatment. Nearly half of sulfate was lower than 0.5 kDa which indicates that sulfate hardly treated by NF membranes. SUVA₂₅₄ values after anaerobic treatment were generally higher than 2 l mg^-1m^-1 which indicates that membrane concentrate was in hydrophobic characteristics.

Synthesis characterization and sorption properties of a sorbent synthesized using slag and red mud: Arsenic removal from spiked aqueous solutions

Pentari D., Alevizos G., Repouskou E. and Korela S., Pages:339-347

DOI:

https://doi.org/10.30955/gnj.001873

Paper Topic:

Water and Wastewater Treatment

Issue:

Issue 2

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Abstract

The aim of the present study was to synthesize a sorbent, for arsenic removal from aqueous solutions, reusing two waste materials (slag and red mud). The sorbent was prepared after chemical and thermal treatment, during which amorphous silica sol and FeOOH sol were produced simultaneously and form Fe-Si complexes on the surface of the slag. To characterize the sorbent Powder X-ray diffraction (XRD); Fourier transform infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM-EDX) were applied. The surface area (BET method) and the Point of Zero Charge (PZC) of the sorbent were determined.). The sorption efficiency of the sorbent produced was investigated with kinetic and equilibrium studies, performed in batch conditions. The concentration of arsenic in solutions was determined by electro thermal atomic absorption spectroscopy (GF-AAS). The results of the study showed that with the described process, using metallurgical wastes, iron oxyhydroxides were “loaded” onto slag producing an effective sorbent for arsenic removal. Kinetic experiments proved that equilibrium was achieved within 15 hours, while the maximum adsorption capacity as evidenced by equilibrium experiments, was 16.14 mg g^-1. Data proved to fit better to the Langmuir equation.

Cadmium Removal by using Pumice Modified with Iron Nanoparticles from Aqueous Solutions

Shokoohi R, Azarian G., Mehdipour M. and Zolghadrnasab H.. , Pages:426-436

DOI:

https://doi.org/10.30955/gnj.001854

Paper Topic:

Water and Wastewater Treatment

Issue:

Issue 2

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Abstract

In this study, the removal of cadmium by using pumice coated with iron nanoparticles (INPs) from synthetic wastewater was investigated. The effects of parameters influencing adsorption: contact time (10-20 min), pH (3-9), initial cadmium concentration (25-125 mg l^-1) and adsorbent dose (2-10 g l^-1) were studied. The pumice stone used in this research was, first, crashed and then sieved with 20 mesh standard sieves (0.85 mm); finally, it was coated with INPs. An atomic absorption spectrophotometer was used to measure cadmium contents and isotherm models and adsorption kinetics were studied. The results showed the adsorption process of cadmium reached equilibrium at contact time of 80 min. With increasing pH solution, the efficiency enhanced which peaked at pH 7-8. Cadmium concentration increase resulted in a decrease in efficiency, whereas adsorbent dose increase improved it. Equilibrium data of adsorption followed isotherms models: Langmuir and Freundlich. The highest removal efficiency and adsorption capacity were, respectively, 83% and 17.27 mg g^-1. Furthermore, absorption kinetics is better described by the pseudo second-order model. According to the results obtained, pumice coated with INPs is an effective adsorbent and can be introduced as a suitable option in practical applications

Effect of sewage-contaminated water on seed production, heavy metals accumulation and seedling emergence in oat

Moradi S., Heidari H., Saeidi M. and Nosratti I., Pages:329-338

DOI:

https://doi.org/10.30955/gnj.001838

Paper Topic:

Water and Wastewater Treatment

Issue:

Issue 2

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Abstract

Two pot experiments were carried out to investigate effect of deficit irrigation with wastewater on seed yield, heavy metals and seedling emergence in oat (Avena sativa). The research at seedling stage included different ratios of sewage-contaminated water (100% well water, 75% well water + 25% wastewater, 50% well water + 50% wastewater, 25% well water + 75% wastewater and 100% wastewater) and three irrigation intervals (1, 2 and 3 days). The research at complete plant stage included different ratios of sewage-contaminated water used at seedling stage and irrigation intervals of 2, 3 and 4 days. Results showed that at oat seedling stage, irrigation interval of 1 days and 100% wastewater produced the highest seedling weight. Irrigation interval of 3 days with 100% wastewater had the lowest seedling emergence. At complete plant stage, by increasing wastewater concentration, leaf chlorophyll content was increased, but relative water content was decreased. 100% wastewater produced the highest seed yield, 1000-seed weight, concentrations of zinc, copper and potassium. According to references, the concentration of studied heavy metals was lower than dangerous threshold.

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Global NEST Journal

Volume 18 - 2016

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