scholarly journals Effect of iron treatment and equilibrium pH on the kinetics of removal of some substituted phenols from synthetic wastewater onto Nostoc sp. biomass

2020 ◽  
Vol 81 (10) ◽  
pp. 2140-2151
Author(s):  
Namrata Gururani ◽  
Devesh Bhatt ◽  
Anjana Srivastava ◽  
Prakash Chandra Srivastava
Keyword(s):  
Cost Effective ◽  
Synthetic Wastewater ◽  
Complexation Reaction ◽  
Substituted Phenols ◽  
Cost Effective Method ◽  
Iron Treatment ◽  
Phenolic Group ◽  
Pseudo Second Order ◽  
The Fourier Transform ◽  
Kinetics Of

Abstract Substituted phenols, such as 4-Nitrophenol (4-NP) and 2,4-Dichlorophenol (2,4-DCP), that are present in industrial wastewaters are considered as priority pollutants due to their toxic effects. Their removal by biosorption presents an eco-friendly, cost-effective method. The kinetics of removal of 4-NP and 2,4-DCP by untreated Nostoc sp. (UNB) and Fe-treated Nostoc sp. biomass (FNB) were studied at three different pH (4.0, 7.0 and 9.0). The highest sorption of both phenols (2.28 mg 4-NP and 1.51 mg 2,4-DCP g−1) coupled with the lowest cumulative percentage desorption was recorded with FNB at pH 7.0. The sorption of both phenols by UNB and FNB was best accounted for by pseudo-second-order kinetics. Compared to UNB, FNB had significantly higher equilibrium sorption capacities for both phenols at all the three pH values and also higher sorption rate constants of 4-NP at pH 4 and 9 and of 2,4-DCP at pH 4 and 7. The Fourier transform infrared spectroscopy (FTIR) analysis showed that –OH and COO− groups of UNB interacted with Fe+3. The sorption of 4-NP and 2,4-DCP on UNB was likely through H-bonding/structural cation bridging with the phenolic group, while their sorption onto FNB appeared to be a complexation reaction with very low reversibility.

Final products and kinetics of biochemical and chemical sulfide oxidation under microaerobic conditions

2018 ◽  
Vol 78 (9) ◽  
pp. 1916-1924 ◽  
Author(s):  
Lucie Pokorna-Krayzelova ◽  
Dana Vejmelková ◽  
Lara Selan ◽  
Pavel Jenicek ◽  
Eveline I. P. Volcke ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Oxidation Rate ◽  
Elemental Sulfur ◽  
Sulfide Oxidation ◽  
Cost Effective ◽  
Anaerobic Treatment ◽  
Batch Experiments ◽  
Cost Effective Method ◽  
Microaerobic Conditions ◽  
Kinetics Of

Abstract Hydrogen sulfide is a toxic and usually undesirable by-product of the anaerobic treatment of sulfate-containing wastewater. It can be removed through microaeration, a simple and cost-effective method involving the application of oxygen-limiting conditions (i.e., dissolved oxygen below 0.1 mg L−1). However, the exact transformation pathways of sulfide under microaerobic conditions are still unclear. In this paper, batch experiments were performed to study biochemical and chemical sulfide oxidation under microaerobic conditions. The biochemical experiments were conducted using a strain of Sulfuricurvum kujiense. Under microaerobic conditions, the biochemical sulfide oxidation rate (in mg S L−1 d−1) was approximately 2.5 times faster than the chemical sulfide oxidation rate. Elemental sulfur was the major end-product of both biochemical and chemical sulfide oxidation. During biochemical sulfide oxidation elemental sulfur was in the form of white flakes, while during chemical sulfide oxidation elemental sulfur created a white suspension. Moreover, a mathematical model describing biochemical and chemical sulfide oxidation was developed and calibrated by the experimental results.

Interaction Influence of Contact Time and pH on Cobalt Retention by Carbon Nanotubes Bearing Various Loads of TiO2 and Fe3O4

2021 ◽  
Vol 17 ◽  
Author(s):  
Ismail Fasfous ◽  
Amjad El-Sheikh ◽  
Anas Awad ◽  
Yahya El-Degs ◽  
Jamal Dawoud
Keyword(s):  
Carbon Nanotubes ◽  
Removal Rate ◽  
Cost Effective ◽  
Research Area ◽  
Second Order ◽  
Nano Materials ◽  
Solution Ph ◽  
Retention Capacity ◽  
Pseudo Second Order ◽  
Kinetics Of

Background: Nano-materials have facilitated remarkable advances in the remediation of many environmental problems. A few studies have tackled the removal of Co(II) from aqueous solutions using nano-materials. Herein, we recently studied the retention kinetics of cobalt species on carbon nanotubes (CNT) bearing different amounts of TiO2 and Fe3O4 nano-materials individually. c Method: CNT and their TiO2/Fe3O4-modified nano-material forms were well characterized. Cobalt retention by these adsorbents was investigated at different influencing factors: Co(II) content, solution pH, and time. The kinetic data were fitted with pseudo-first-order, pseudo-second-order rate models and intra-particle diffusion models for better elucidation of the mechanism of Co retention. Results: XRD evidenced the formation of TiO2 and Fe3O4. High loads of both oxides were needed for higher and faster Co retention by CNT. Co retention capacity increased with increasing the solution pH. The pseudo-second-order model presented the kinetics of Co retention at 30 oC, and 48% of available capacity was attained within the first hour of interaction by CNT-TiO2 and with a moderate S/L ratio of 0.5 g/L. Co retention was increased with the amount of oxide to reach a maximum value of 16. 40 mg/g (90.2% TiO2) and 13.60 mg/g (48.2% Fe3O4). The Jovanović equilibrium model predicted the maximum retention values as the nearest to the experimental ones. Conclusion: The potential of CNT-Fe3O4 /TiO2 nano-materials has been successfully demonstrated for the removal of cobalt, which makes them highly attractive and cost-effective adsorbents for wastewater treatment. The reported retention and removal rate values were relatively better than those seen in the literature. Loading different active oxides by CNT is an interesting research area as selective adsorbents can be fabricated with affordable experimental costs.

scholarly journals Removal of Fluoride from Water by Adsorption onto Fired Clay Pots: Kinetics and Equilibrium Studies

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
G. P. Kofa ◽  
V. H. Gomdje ◽  
C. Telegang ◽  
S. Ndi Koungou
Keyword(s):  
Ionic Strength ◽  
Rural Areas ◽  
Cost Effective ◽  
Equilibrium Studies ◽  
Fluoride Adsorption ◽  
Jar Test ◽  
Cost Effective Method ◽  
Pseudo Second Order ◽  
Fire Wood ◽  
Clay Pots

Excessive fluoride in potable water is a serious health problem in rural areas of many developing countries. Hence, there is a need to find a simple and cost-effective method for water defluoridation in such areas. In the northern part of Cameroon, clay pots are used for cooking food and water storage. The firing of these pots consists of intensive burning using fire wood. They were tested as a potential adsorbent for removing excess fluoride from water. Experiments were carried out in a jar test at room temperature (25 ± 2°C). Effects of contact time (0–90 min), pH (4, 5, 7, 8, and 9), stirring speed (60, 90, 120, and 200 rpm), and ionic strength (0–1000 mg/L) were investigated. Results showed that equilibrium was attained in 10 min whatever the pH. Pseudo-second-order and pore diffusion models described well the adsorption process. The highest amount of fluoride adsorbed (1.6 mg/g) was obtained at pH 4-5 and the optimum stirring speed is 120 rpm. Ionic strength has a significant effect on fluoride adsorption.

Impact of biodegradable trenching slurry on iron treatment wall performance

1998 ◽  
Vol 38 (7) ◽  
pp. 49-53
Author(s):  
D. Navon ◽  
R. C. Loehr ◽  
H. M. Liljestrand ◽  
D. E. Daniel
Keyword(s):  
Cost Effective ◽  
Treatment Barriers ◽  
First Order ◽  
Commercial Grade ◽  
Cost Effective Method ◽  
Iron Treatment ◽  
Degradation Rates ◽  
Significant Difference ◽  
Polymer Slurry ◽  
The Impact

Biodegradable trenching slurries have been proposed as a cost effective method for the emplacement of reactive treatment barriers. In this study, the impact of a bio-polymer slurry on the ability of zero-valent iron to reductively dehalogenate trichloroethene was measured. First-order trichloroethene degradation rates were determined for three types of iron, with and without slurry in batch reactions. For the commercial grade iron, a significant difference was determined between the surface area normalized rate without slurry (1.78E-4 L m−2 hr−1) and with slurry (1.23E-4 L m−2 hr−1). However, no significant difference was determined with or without bio-slurry for the reagent grade irons.

Bentonite-Copolymer Composite for Removing Basic Fuchsin

2017 ◽  
Vol 726 ◽  
pp. 345-349 ◽  
Author(s):  
Yu Feng He ◽  
Hong Li ◽  
Zhen Hua Zhang ◽  
Ting Jun Lu ◽  
Rong Min Wang
Keyword(s):  
Freundlich Isotherm ◽  
Cost Effective ◽  
Molecular Formula ◽  
Order Kinetic ◽  
Basic Fuchsin ◽  
Cost Effective Method ◽  
Pseudo Second Order ◽  
Polymer Adsorbent ◽  
In Situ Copolymerization

Basic Fuchsin (BF) is a toxic triphenylmethane dye with molecular formula C20H20ClN3, which is easy to caused serious public health problems. There is a need to develop a cost effective method for its removal from the wastewater containing BF. Here, a novel composite polymer adsorbent, poly (maleic anhydride - acrylic acid - vinyl acetate)/Na-bentonite composite cross-linked with N,N'-methylenebisacrylamide was prepared by in situ copolymerization. The polymer adsorbent (NaB-PMAVM) was characterized and applied to remove BF. It was found that the removal of BF reached to 95.96%. The adsorption isotherms and kinetics were best-fit with the Freundlich isotherm model and the pseudo-second-order kinetic, respectively.

CAD Of Anticorrosive Protection Of Steel Structures

2019 ◽  
pp. 18-23
Keyword(s):  
Protective Coating ◽  
Computer Aided Design ◽  
Steel Structures ◽  
Cost Effective ◽  
Operating Conditions ◽  
Computational Tool ◽  
Protection Method ◽  
Cost Effective Method ◽  
The Cost ◽  
Aided Design

The choice of cost-effective method of anticorrosive protection of steel structures is an urgent and time consuming task, considering the significant number of protection ways, differing from each other in the complex of technological, physical, chemical and economic characteristics. To reduce the complexity of solving this problem, the author proposes a computational tool that can be considered as a subsystem of computer-aided design and used at the stage of variant and detailed design of steel structures. As a criterion of the effectiveness of the anti-corrosion protection method, the cost of the protective coating during the service life is accepted. The analysis of existing methods of steel protection against corrosion is performed, the possibility of their use for the protection of the most common steel structures is established, as well as the estimated period of effective operation of the coating. The developed computational tool makes it possible to choose the best method of protection of steel structures against corrosion, taking into account the operating conditions of the protected structure and the possibility of using a protective coating.

Monitoring effluent quality in hypertrophic wastewater reservoirs using remote sensing

1996 ◽  
Vol 33 (8) ◽  
pp. 23-29 ◽  
Author(s):  
I. Dor ◽  
N. Ben-Yosef
Keyword(s):  
Water Quality ◽  
Theoretical Model ◽  
Principal Component ◽  
Cost Effective ◽  
Operational Parameters ◽  
Effluent Quality ◽  
Optical Images ◽  
Routine Monitoring ◽  
Cost Effective Method ◽  
Wastewater Quality

About one hundred and fifty wastewater reservoirs store effluents for irrigation in Israel. Effluent qualities differ according to the inflowing wastewater quality, the degree of pretreatment and the operational parameters. Certain aspects of water quality like concentration of organic matter, suspended solids and chlorophyll are significantly correlated with the water column transparency and colour. Accordingly optical images of the reservoirs obtained from the SPOT satellite demonstrate pronounced differences correlated with the water quality. The analysis of satellite multispectral images is based on a theoretical model. The model calculates, using the radiation transfer equation, the volume reflectance of the water body. Satellite images of 99 reservoirs were analyzed in the chromacity space in order to classify them according to water quality. Principal Component Analysis backed by the theoretical model increases the method sensitivity. Further elaboration of this approach will lead to the establishment of a time and cost effective method for the routine monitoring of these hypertrophic wastewater reservoirs.

A Cost-Effective Method to Prepare Pure Vildagliptin

2013 ◽  
Vol 10 (3) ◽  
pp. 159-163 ◽  
Author(s):  
Jun Peng ◽  
Yue Feng ◽  
Zhu Tao ◽  
Yingjie Chen ◽  
Xiangnan Hu
Keyword(s):  
Cost Effective ◽  
Cost Effective Method
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