Organic matter and heavy metal removals from complexed metal plating effluent by the combined electrocoagulation/Fenton process

2010 ◽  
Vol 61 (10) ◽  
pp. 2617-2624 ◽  
Author(s):  
I. Kabdaşlı ◽  
T. Arslan ◽  
I. Arslan-Alaton ◽  
T. Ölmez-Hancı ◽  
O. Tünay
Keyword(s):  
Organic Matter ◽  
Metal Removal ◽  
Treatment Method ◽  
Fenton Process ◽  
Toc Removal ◽  
Operation Conditions ◽  
Metal Plating ◽  
Wide Range ◽  
Initial Ph ◽  
H2o2 Addition

In the present study, the treatment of metal plating wastewater containing complexed metals originating from the nickel and zinc plating process by electrocoagulation (EC) using stainless steel electrodes was explored. In order to improve the organic matter removal efficiency, the effect of H2O2 addition to the electrocoagulation (the combined EC/Fenton process) application was investigated. For this purpose, a wide range of H2O2 concentrations varying between 15 and 230 mM was tested. All EC and EC/Fenton processes were performed at an initial pH of 2.6 and at an optimized current density of 22 mA/cm2. Although up to 30 mM H2O2 addition improved the EC process performance in terms of organic matter abatement, the highest COD and TOC removal efficiencies were obtained for the combined EC/Fenton process in the presence of 20 mM H2O2. Nickel and zinc were completely removed for all runs tested in the present study after pH adjustments. At the optimized operation conditions, the combined EC/Fenton process proved to be an alternative treatment method for the improvement of organic matter reduction as well as complexed metal removal from metal plating industry wastewater.

scholarly journals Biochar for wastewater treatment – a Minireview**

2021 ◽  
pp. 63-66
Author(s):  
Lena Johansson Westholm
Keyword(s):  
Wastewater Treatment ◽  
Functional Groups ◽  
Metal Removal ◽  
Thermochemical Treatment ◽  
Treatment Method ◽  
Transformation Method ◽  
Waste Products ◽  
Vast Number ◽  
Filter Materials ◽  
Wide Range

Wastewater must be treated no matter if is reused or discharged into the environment. The cost of wastewater treatment may be rather high, though other solutions are sought. One of them is the application of filter materials. The filter materials have been used for removal of various pollutants in different kinds of wastewater and a wide range of filter materials (natural products, industrial waste products or man-made products) have been investigated. Among these filter materials, biochar has attracted increasing attention during the last decade. A large number of publications are devoted to production, properties and potential applications of biochar. They reveal that biochar is capable of removing pollutants of different kinds from wastewaters. A number of experiments was focused on the removal of commonly found pollutants, e.g. nutrients, heavy metals, organic matters and pharmaceuticals. It was found that the origin of the feedstock and the thermochemical treatment method are tightly connected and will have an impact on the properties of the biochar. A large number of different feedstock material like wood or wood residues, garden wastes or human and animal wastes can be transformed into biochar by torrefaction and pyrolysis. Properties of biochar will depend on transformation method. Surface area, porosity, pH, surface charge, functional groups and mineral components contribute to a vast number of mechanisms that are responsible for the metal removal, e.g. electrostatic interaction between the surface of the biochar and the specific metal, the cation exchange capacity between metals and protons and the alkaline metals on the surface of the biochar, metal complexation with functional groups and precipitation of metals that form non-soluble compounds. Biochar was successfully applied in wetlands systems to increase the removal of some targeted pollutants.

Treatment of tetrahydrofuran wastewater by the Fenton process: response surface methodology as an optimization tool

2014 ◽  
Vol 69 (5) ◽  
pp. 1080-1087 ◽  
Author(s):  
Xianzhong Cao ◽  
Huiqing Lou ◽  
Wei Wei ◽  
Lijuan Zhu
Keyword(s):  
Reaction Time ◽  
Response Surface ◽  
Removal Efficiency ◽  
Oxygen Demand ◽  
Treatment Method ◽  
Degradation Pathway ◽  
Fenton Process ◽  
Operating Variables ◽  
Rsm Optimization ◽  
Initial Ph

In this study, the Box-Benkhen design and response surface method (RSM) were applied to evaluate and optimize the operating variables during the treatment of tetrahydrofuran (THF) wastewater by Fenton process. The four factors investigated were initial pH, Fe2+ dosage, H2O2 dosage and reaction time. Statistical analysis showed the linear coefficients of the four factors and the interactive coefficients such as initial pH/Fe2+ dosage, initial pH/H2O2 dosage and Fe2+ dosage/H2O2 dosage all significantly affected the removal efficiency. The RSM optimization results demonstrated that the chemical oxygen demand (COD) removal efficiency could reach up to 47.8% when initial pH was 4.49, Fe2+ dosage was 2.52 mM, H2O2 dosage was 20 mM and reaction time was 110.3 min. Simultaneously, the biodegradability increased obviously after the treatment. The main intermediates of 2-hydroxytetrahydrofuran, γ-butyrolactone and 4-hydroxybutanoate were separated and identified and then a simple degradation pathway of THF was proposed. This work indicated that the Fenton process was an efficient and feasible pre-treatment method for THF wastewater.

Integration of US/Fe2+ and photo-Fenton in sequencing for degradation of landfill leachate

2015 ◽  
Vol 73 (2) ◽  
pp. 260-266 ◽  
Author(s):  
F. G. Zha ◽  
D. X. Yao ◽  
Y. B. Hu ◽  
L. M. Gao ◽  
X. M. Wang
Keyword(s):  
Removal Efficiency ◽  
Landfill Leachate ◽  
Oxygen Demand ◽  
Gas Chromatography Mass Spectrometry ◽  
Fenton Process ◽  
Optimal Conditions ◽  
Initial Concentration ◽  
Toc Removal ◽  
The Us ◽  
Initial Ph

The landfill leachate treated by sonication in presence of Fe2+ (US/Fe2+) and then by photo-Fenton achieved the highest total organic carbon (TOC) removal efficiency among the screened processes. The lower initial pH, dosage of Fe2+ and initial concentration of leachate were helpful in raising TOC removal efficiency of leachate by US/Fe2+. The optimal conditions for the US-photo-Fenton process were as follows: initial pH at 3.0, [H2O2]/[TOC0] at 2, [H2O2]/[Fe2+] at 5 and initial concentration of landfill leachate at 600 mg/L. The removal efficiency of TOC, chemical oxygen demand (COD) and 5-day biochemical oxygen demand (BOD5) were 68.3, 79.6 and 58.2%, while the BOD5/COD rose from 0.20 to 0.43 at optimum condition. Based on gas chromatography–mass spectrometry (GC-MS) results, 36 of a total of 56 pollutants were completely degraded by US-photo-Fenton treatment.

Role of Rhizoremediation in Decontaminating Some Hazardous Pollutants

2017 ◽  
pp. 213-246
Author(s):  
Hossein Farraji ◽  
Nastaein Qamaruz Zaman ◽  
Mohammad Ali Zahed ◽  
Hamed Faraji
Keyword(s):  
High Efficiency ◽  
Metal Removal ◽  
Heavy Metal Removal ◽  
Treatment Method ◽  
Terrestrial Environment ◽  
Wide Range ◽  
Pollutants Removal ◽  
Hazardous Pollutants ◽  
Process Interaction

Rhizoremediation is a natural biological base, multifactorial operation treatment method which highly depends to environmental factors especially in terrestrial environment as operation of remediation process. Interaction and relationship between microbial community and plant roots is specific attraction and advantages of this advanced treatment method. Decontamination efficiency and time could be highly manageable by operation and rhizoaugmentation. Rhizoremediation is advanced compact combination of phytoextraction, phytovolatilization, phytotransformation and phytostabilization. High efficiency of pollutants removal, adaptive and wide range of operation and augmentation factors cause of emerging application of this for biodegradable organic compounds and heavy metals. Selection of suitable plant and joining them with comfortable microbial couples is a function which can plane simultaneously removal system. This chapter will present an overview on PAH, TPH, PCB and heavy metal removal and mechanism of decontamination, plant selection and augmentation process.

Coagulation/flocculation/ultrafiltration for natural organic matter removal in drinking water production

2004 ◽  
Vol 4 (5-6) ◽  
pp. 215-222 ◽  
Author(s):  
A.R. Costa ◽  
M.N. de Pinho
Keyword(s):  
Drinking Water ◽  
Organic Matter ◽  
Natural Organic Matter ◽  
Membrane Fouling ◽  
Membrane Filtration ◽  
Membrane Surface ◽  
Water Production ◽  
Cellulose Acetate Membranes ◽  
Wide Range ◽  
Drinking Water Production

Membrane fouling by natural organic matter (NOM), namely by humic substances (HS), is a major problem in water treatment for drinking water production using membrane processes. Membrane fouling is dependent on membrane morphology like pore size and on water characteristics namely NOM nature. This work addresses the evaluation of the efficiency of ultrafiltration (UF) and Coagulation/Flocculation/UF performance in terms of permeation fluxes and HS removal, of the water from Tagus River (Valada). The operation of coagulation with chitosan was evaluated as a pretreatment for minimization of membrane fouling. UF experiments were carried out in flat cells of 13.2×10−4 m2 of membrane surface area and at transmembrane pressures from 1 to 4 bar. Five cellulose acetate membranes were laboratory made to cover a wide range of molecular weight cut-off (MWCO): 2,300, 11,000, 28,000, 60,000 and 75,000 Da. Severe fouling is observed for the membranes with the highest cut-off. In the permeation experiments of raw water, coagulation prior to membrane filtration led to a significant improvement of the permeation performance of the membranes with the highest MWCO due to the particles and colloidal matter removal.

Treatment of a complex landfill leachate with peat

1978 ◽  
Vol 5 (1) ◽  
pp. 83-97 ◽  
Author(s):  
Robert D. Cameron
Keyword(s):  
Chemical Oxygen Demand ◽  
Ferric Chloride ◽  
Landfill Leachate ◽  
Metal Removal ◽  
Oxygen Demand ◽  
Treatment Method ◽  
Manganese Concentration ◽  
Chemical Pretreatment ◽  
Iron Manganese

The use of cheap, locally available peat as a treatment method for landfill leachate was investigated by passing leachate through plexiglass columns filled with an amorphous-granular peat. Preliminary adjustment of pH showed that reducing pH to 4.8 dramatically reduced adsorption. Increasing the pH to 8.4, metal removal was increased owing to filtration of precipitated metals. The best adsorption of metals occurred at the 'natural' pH of 7.1. Manganese was found to be the limiting pollutant. At the 0.05 mg/ℓ maximum acceptable manganese concentration 94% of the total metals were removed, requiring 159 kg of peat per 1000 ℓ of leachate.Resting the peat for 1 month did significantly increase removal capacity.Desorption of some contaminants occurred when water was percolated through the peat. The desorption test effluent was not toxic to fish although iron, lead and COD (chemical oxygen demand) exceeded acceptable values.Chemical pretreatment using lime and ferric chloride achieved significant iron, manganese and calcium removals. Chemical pretreatment followed by peat adsorption offered no advantage other than reducing toxicity to fish.Peat treatment alone was effective in reducing concentrations to a level that was non-toxic to fish.

scholarly journals Study on Friction in Automotive Shock Absorbers Part 1: Friction Simulation Using a Dynamic Friction Model in the Contact Zone of an FEM Model

Vehicles ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 212-232
Author(s):  
Ludwig Herzog ◽  
Klaus Augsburg
Keyword(s):  
Ride Comfort ◽  
Viscous Friction ◽  
Simulation Method ◽  
Friction Model ◽  
Model Parameters ◽  
Dynamic Friction ◽  
Friction Modeling ◽  
Shock Absorbers ◽  
Operation Conditions ◽  
Wide Range

The important change in the transition from partial to high automation is that a vehicle can drive autonomously, without active human involvement. This fact increases the current requirements regarding ride comfort and dictates new challenges for automotive shock absorbers. There exist two common types of automotive shock absorber with two friction types: The intended viscous friction dissipates the chassis vibrations, while the unwanted solid body friction is generated by the rubbing of the damper’s seals and guides during actuation. The latter so-called static friction impairs ride comfort and demands appropriate friction modeling for the control of adaptive or active suspension systems. In this article, a simulation approach is introduced to model damper friction based on the most friction-relevant parameters. Since damper friction is highly dependent on geometry, which can vary widely, three-dimensional (3D) structural FEM is used to determine the deformations of the damper parts resulting from mounting and varying operation conditions. In the respective contact zones, a dynamic friction model is applied and parameterized based on the single friction point measurements. Subsequent to the parameterization of the overall friction model with geometry data, operation conditions, material properties and friction model parameters, single friction point simulations are performed, analyzed and validated against single friction point measurements. It is shown that this simulation method allows for friction prediction with high accuracy. Consequently, its application enables a wide range of parameters relevant to damper friction to be investigated with significantly increased development efficiency.

scholarly journals Gradient HPLC in the determination of drug lipophilicity and acidity

2001 ◽  
Vol 73 (9) ◽  
pp. 1465-1475 ◽  
Author(s):  
Roman Kaliszan ◽  
Piotr Haber ◽  
Tomasz Baczek ◽  
Danuta Siluk
Keyword(s):  
Mobile Phase ◽  
High Performance ◽  
Standard Procedure ◽  
Gradient Elution ◽  
Log P ◽  
Retention Data ◽  
Organic Modifier ◽  
Wide Range ◽  
Aqueous Component ◽  
Initial Ph

The linear-solvent strength (LSS) model of gradient elution in high-performance liquid chromatography (HPLC) has been demonstrated to provide parameters of lipophilicity and acidity of analytes. pKa and log kw values are determined in three gradient runs. The first two experiments use an aqueous buffered eluent with a wide-range organic modifier gradient at pH of buffer, providing suppression of ionization of the analyte. That experiment allows an estimate of contents of the organic modifier in the mobile phase (%B), producing requested retention coefficient, k, for the nonionized form of the analyte. The next experiment is carried out with the latter %B and a pH-gradient of the aqueous component of the eluent that is sufficient to overlap possible pKa value of the analyte. The initial pH of the buffer used to make the mobile phase is selected to insure that the analyte is in nonionized form. The resulting retention time allows an estimate of pKa in a solvent of the given %B.The log kw parameter obtained correlated well with the corresponding value obtained by the standard procedure of extrapolation of retention data determined in a series of isocratic measurements. The correlation between log kw and the reference parameter of lipophilicity, log P, was very good for a series of test analytes. The values of pKa were found to correlate with the literature pKa data determined in water for a set of aniline derivatives studied.

A generally applicable pedotransfer function that estimates field capacity and permanent wilting point from soil texture and bulk density

2008 ◽  
Vol 88 (5) ◽  
pp. 761-774 ◽  
Author(s):  
J. A. P. Pollacco
Keyword(s):  
Organic Matter ◽  
Soil Moisture ◽  
Bulk Density ◽  
Soil Texture ◽  
The United States ◽  
Pedotransfer Functions ◽  
Pedotransfer Function ◽  
Data Set ◽  
Wide Range ◽  
Fitting Parameters

Hydrological models require the determination of fitting parameters that are tedious and time consuming to acquire. A rapid alternative method of estimating the fitting parameters is to use pedotransfer functions. This paper proposes a reliable method to estimate soil moisture at -33 and -1500 kPa from soil texture and bulk density. This method reduces the saturated moisture content by multiplying it with two non-linear functions depending on sand and clay contents. The novel pedotransfer function has no restrictions on the range of the texture predictors and gives reasonable predictions for soils with bulk density that varies from 0.25 to 2.16 g cm-3. These pedotransfer functions require only five parameters for each pressure head. It is generally accepted that the introduction of organic matter as a predictor improves the outcomes; however it was found by using a porosity based pedotransfer model, using organic matter as a predictor only modestly improves the accuracy. The model was developed employing 18 559 samples from the IGBP-DIS soil data set for pedotransfer function development (Data and Information System of the International Geosphere Biosphere Programme) database that embodies all major soils across the United States of America. The function is reliable and performs well for a wide range of soils occurring in very dry to very wet climates. Climatical grouping of the IGBP-DIS soils was proposed (aquic, tropical, cryic, aridic), but the results show that only tropical soils require specific grouping. Among many other different non-climatical soil groups tested, only humic and vitric soils were found to require specific grouping. The reliability of the pedotransfer function was further demonstrated with an independent database from Northern Italy having heterogeneous soils, and was found to be comparable or better than the accuracy of other pedotransfer functions found in the literature. Key words: Pedotransfer functions, soil moisture, soil texture, bulk density, organic matter, grouping

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