Removal of Humic Substances by Repeated Mixing with PACl

2009 ◽  
Vol 4 (2) ◽  
Author(s):  
H. Nagare ◽  
T. Aso ◽  
S. Yoshida ◽  
K. Ebie
Keyword(s):  
Humic Substances ◽  
Removal Efficiency ◽  
Color Removal ◽  
Coagulation Process ◽  
Coagulant Dosage

Focusing on the improvement of removal efficiency of humic substances by coagulation, coagulation-flocculation processes were applied not only once but more than twice to the water being treated, and the effect of repeated coagulation was evaluated in jar-tests. With more than the critical dosage of PACl (15 mg/l), approximately 30% of color removal was attained in typical one-pass treatment, whilst maximum 65% removal was achieved by repeating the coagulation twice. Repeating coagulation enhances the coagulation process to achieve higher color removal efficiency, and can reduce the coagulant dosage.

scholarly journals Coagulation-Flocculation Treatment for Naphthol Green Band Flour Wastewater

2020 ◽  
Vol 6 (12) ◽  
pp. 190-197
Author(s):  
Bukola M. ADESANMI Yung-Tse HUNG and Howard H. PAUL
Keyword(s):  
Removal Efficiency ◽  
Industrial Effluent ◽  
Color Removal ◽  
Preliminary Treatment ◽  
Dye Wastewater ◽  
Synthetic Dye ◽  
Coagulation Process ◽  
Coagulant Dosage ◽  
Wastewater Samples ◽  
The Impact

The interference of synthetic dye in the water bodies and environment poses a risk to both human and environmental health. Due to the recalcitrant nature of dye and presence of many other pollutants in industrial wastewater, efficient method of treatment of industrial effluent is required to address the lingering problem over the years. To address this major concern, experimental was carried out on synthetic dye and flour wastewater treatment by coagulation-flocculation while varying operating parameters (dosage, concentration, coagulant type etc.). The effectiveness of coagulation-flocculation process for the removal of Naphthol Green B in a mixture of dye wastewater and flour wastewater at different concentrations (50 ppm, 100 ppm, 150 ppm, 200 ppm) was investigated. Using 3 coagulant (FeCl3, FeSO4 and Al2(SO4)3), color removal efficiency was also investigated. The effectiveness of the coagulation process was measured for transmittance and absorbance as indices using UV-Vis Spectrophotometer. Also, the total organic carbon (TOC) was measured. Transmittance and absorbance values of 99.6% and 0.001 respectively were achieved post treatment. Ferric Chloride and Aluminum Sulfate gave better results than Ferrous Sulfate which gave the poorest transmittance and absorbance values indicating reduced color removal efficiency. The results of this study revealed that coagulation process is an efficient preliminary treatment for appreciable suspended particles and color removal from dye wastewater. It also showed the impact of coagulant dosage, dye strength and combined wastewater samples on the removal efficiency and resulting effluent quality.

Decolorization of Reactive Brilliant Red X-3B Simulated Dye Water by Novel Coagulants

2013 ◽  
Vol 743-744 ◽  
pp. 665-668
Author(s):  
Ji Zhou Li ◽  
Xu Yin Yuan ◽  
Ming Tian ◽  
Hao Ran Ji ◽  
Wan Jiang
Keyword(s):  
Removal Efficiency ◽  
Dye Removal ◽  
Color Removal ◽  
Solution Temperature ◽  
Maximum Efficiency ◽  
Coagulant Dosage ◽  
Decolorization Efficiency ◽  
Initial Ph ◽  
Simulated Wastewater ◽  
Ph Range

Five novel coagulants, DC-491, Fennofix K97, BWD-01, MD-03 and MD-04 were chosen to treat reactive brilliant red X-3B simulated wastewater by jar tests. The results showed that the decolorization efficiencies were all higher than 75% at initial pH 8.2 and temperature 20 after 20 minutes of reaction. Then, two typical coagulants, BWD-01 and MD-04 which had better performance were chosen to study the effect of dye removal of X-3B at different operating parameters, including coagulant dosage, pH, sedimentaion time and reaction temperature of simulated wastewater. Decolorization efficiency of MD-04 for X-3B solution was higher than 80% in pH range from 3 to 9, while for BWD-01, efficiency increased from 37.3% to 82.3% in this pH range. For both BWD-01 and MD-04, the color removal efficiency increased as the solution temperature increased and the maximum efficiency was over 94% at 40. Small changes in the color removal efficiency were observed after 1 hour sedimentation for both coagulants.

Optimization of Coagulation Process for Disperse Navy Blue Dye Wastewater Treatment Using Response Surface Methodology

2014 ◽  
Vol 977 ◽  
pp. 270-273
Author(s):  
Ming Li ◽  
Yan Zhen Yu ◽  
Guang Yong Yan
Keyword(s):  
Response Surface Methodology ◽  
Wastewater Treatment ◽  
Response Surface ◽  
Removal Efficiency ◽  
Ph Value ◽  
Settling Time ◽  
Blue Dye ◽  
Dye Wastewater ◽  
Coagulation Process ◽  
Coagulant Dosage

A response surface methodology (RSM) was used for the determination of optimum coagulation process conditions for disperse navy blue dye wastewater treatment. The experimental design was Box-Behnken design (BBD) with three operational variables: coagulant dosage, pH value and settling time. The influence of these three independent variables on the chroma removal was evaluated using a second-order polynomial multiple regression model. Quadratic model was predicted for the response variable and the maximum model-predicted chroma removal efficiency was 95%. Based on surface and contour plots, the optimum conditions were obtained to be coagulant dosage of 70.98 mg/L, pH value of 7.46, and settling time of 15.80 min with the actual chroma removal efficiency as 93%.

Polyamidine as a New-Style Coagulant Aid for Dye Wastewater Treatment and its Floc Characteristics

2018 ◽  
Vol 913 ◽  
pp. 930-940
Author(s):  
Mo Xi Xue ◽  
Bao Yu Gao ◽  
Xing Xu ◽  
Wen Song
Keyword(s):  
Removal Efficiency ◽  
Color Removal ◽  
Dye Wastewater ◽  
Atomic Force ◽  
Coagulant Dosage ◽  
Wide Range ◽  
Floc Characteristics ◽  
Coagulation Kinetics ◽  
Floc Strength ◽  
Neutralization Ability

Polyamidine (PA) is a novel high cation coagulant aid for water treatment. In the present study the structure, coagulation ability and floc characteristics (including coagulation kinetics, floc dimension, floc strength and floc recover ability) were discussed. As a dual-coagulation, polyamidine was combined with AlCl3and PAC to remove dispersed yellow from wastewater. The results showed that the polyamidine exhibited higher intrinsic viscosity and higher charge neutralization ability than cationic polyacrylamide (PAM). Atomic force microscopic (AFM) and transmission electronic microscopic (TEM) images showed a dendritic, stretched structure of PA. The dosage of PAC/PA and AlCl3/PA and pH were investigated and optimized. Under the optimum condition, the color removal efficiency reached 96% as the concentration of 14/0.2 mg/L for AlCl3/PA (PA was combined with AlCl3) at pH 6. Meanwhile, the highest decoloring efficiency (97%) was achieved in the process when PAC/PA (PA was combined with PAC) dosage was 18/0.6 mg/L at pH 6.0-8.0. The addition of polyamidine could improve the color removal efficiency, including increasing the zeta potential evidently and reducing the aluminum coagulants dosage as well. Compared with AlCl3/PA, PAC/PA which contained higher polymeric aluminum, exhibited a better coagulation ability to adapt a wide range of pH. However, when PAC/PA and AlCl3/PA expressed the same removal efficiency, AlCl3/PA showed a less coagulant dosage in raw dye wastewater pH. With PA dosages increased, the floc of AlCl3/PA showed a gradually adding strength and recovery ability, but in PAC/PA system the tendency was unclear. In PAC/PA system, PA dosage increase only improved floc density.

scholarly journals Removal of Dyes by Aqueous Mixed Coagulants

2005 ◽  
Vol 5 (1) ◽  
pp. 52
Author(s):  
Peik Yin Ooi ◽  
Tjoon Tow Teng ◽  
A. K. Mohd Omar ◽  
N. A. R. Nik Norulaini
Keyword(s):  
Textile Industry ◽  
Suspended Solids ◽  
Treatment Plant ◽  
Reactive Dye ◽  
Settling Time ◽  
Color Removal ◽  
Jar Test ◽  
Coagulation Process ◽  
Coagulant Dosage ◽  
Coloring Matter

Alum, MgCl2, and mixtures of alum and MgCl2 have been used as coagulant to remove coloring matter in the reactive dye Levafix Brill Blue EBRA. The jar test was used to determine the effectiveness and the optimal condition of the coagulation process in terms of pH of the coagulation process, coagulant dosage, percentage color removal, and floc settling time. Coagulant dosages of 1,000-5,000 ppm were studied. The treatment of textile industry wastewater was done in the treatment plant of a printing mill. The results showed that coagulation by MgCl2 and alum occurs at the removal pH ranges of 10.5-11.0 for MgCl2 and 4.0-6.0 for alum. The mixtures of MgCl2 and alum gave two distinct effective color-removal zones at pH 4-5.5 and pH 8-9.5. The addition of alum to MgCl2 shifted the optimal pH of MgCl2 from 10.5-11. 0 to 8. 0-9.5. The alum dose of 1,000-3,000 ppm in the coagulant mixture increased by 10-25 % the color removal in the alkaline zone. Floc settling time was found to (a) increase with coagulant dose and (b) take longer in the acidic color-removal zone than in the alkaline zone. The presence of alum increased the floc settling time in the alkaline zone. The study done at the treatment plant of a printing mill showed similar results. A mixture of 60% MgClz and 40% alum at an average dosage of 2,800 ppm gave a color removal of 97% and reductions of 88% for COD and 69% for suspended solids. Keywords: Chemical coagulation, color reduction, mixed coagulants, and textile waste.

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.

scholarly journals Characterization and optimization of spectrophotometric colour removal from dye containing wastewater by Coagulation-Flocculation

2018 ◽  
Vol 20 (4) ◽  
pp. 49-59 ◽  
Author(s):  
I.A. Obiora-Okafo ◽  
O.D. Onukwuli
Keyword(s):  
Removal Efficiency ◽  
Contour Plot ◽  
Process Conditions ◽  
Optimization Analysis ◽  
Colour Removal ◽  
Coagulant Dosage ◽  
Main Effect ◽  
Ftir Spectrometer ◽  
Predicted Values ◽  
Central Composite

Abstract The performance of Vigna unguiculata coagulant (VUC) for colour removal from acid dye was investigated in this study. The proximate, structure and morphology of the coagulant were investigated using standard official methods, Fourier-Transform Infrared (FTIR) spectrometer and scanning electron microscopy (SEM), respectively. Response surface methodology (RSM) using face-centred central composite design (FCCD) optimized four process variables including pH, coagulant dosage, dye concentration and time. The colour removal efficiency obtained from the optimization analysis was 99.26% at process conditions of pH 2, coagulant dosage 256.09 mg/l, dye concentration 16.7 mg/l and time 540 min. The verification experiments agreed with the predicted values having a standard error value of 1.96%. Overlay contour plot established optimum areas where the predicted response variable is in an acceptable range (≥ 70%) with respect to optimum conditions. The FCCD approach was appropriate for optimizing the process giving higher removal efficiency when compared to the main effect plots.

scholarly journals USING METAL WASTE SLAGS AS THE HETEROGENEOUS CATALYSTS OF OZONE FOR TREATMENT OF PULP WASTEWATER

2020 ◽  
Vol 58 (3A) ◽  
pp. 1
Author(s):  
Hu Tap Van
Keyword(s):  
Organic Compounds ◽  
Removal Efficiency ◽  
Heterogeneous Catalysts ◽  
Catalytic Ozonation ◽  
Cod Removal ◽  
Color Removal ◽  
Order Kinetic ◽  
First Order ◽  
Iron Slag ◽  
Ozonation Process

Catalytic ozonation is one of the promising treatment methods for removal of persistent organic compounds from water and wastewater. In this study, some metal slags such as: iron slag, lead slag, zinc slag, cadmium slag and copper slag originated from solid waste of Thai Nguyen Non-ferrous Metals Limited Company, Vietnam were used as heterogeneous catalysts for ozonation process to remove organic compounds from pulp wastewater. The effects of the initial pH (pHi) of pulp wastewater and the metal slag dosage on efficiency of decolorization and mineralization of pulp wastewater, in term of COD were investigated. The results indicated that iron slag was the most suitable catalyst for treatment of pulp wastewater by ozonation process with the highest removal efficiency of COD, namely, after 120 min of ozonation (with flowrate of O3 of 3.038 g/h) of the pulp wastewater (initial COD 1809 mg/L), COD removal efficiency, respectively, reached 91,16%; 84%; 83,83 %; 83,91%; 83,41% and 83,14% in the presence of iron, copper, zinc, lead, cadmium slag and ozone alone. Simultaneously, the color was almost completely removed (95.55 – 98.79%) by ozonation processes with using all before-mentioned metal slags as heterogeneous catalysts and ozone alone. Maximum COD and color removal efficiency obtained at pH 7 for ozonation alone and its combinations with iron slag. Moreover, an increase in the iron slag dosage from 0.125 g/L to 2.0 g/L for O3/iron slag could enhance COD and color removal of pulp wastewater. The K values (apparent first-order rate constant values) showed that the COD removal rate followed the pseudo-first-order kinetic model. This study also indicated that the main constituent FeO presence in iron slag reaction with O3 in heterogeneous catalytic ozonation system enhances removal efficiency of color and COD of pulp wastewater.

scholarly journals Influence of the apparent molecular size of humic substances on the efficiency of coagulation using Fenton's reagent

2013 ◽  
Vol 85 (2) ◽  
pp. 833-848 ◽  
Author(s):  
MARCELO DE JULIO ◽  
TATIANE S. DE JULIO ◽  
LUIZ DI BERNARDO
Keyword(s):  
Humic Substances ◽  
Water Samples ◽  
Iron Concentration ◽  
Molecular Size ◽  
Fenton’S Reagent ◽  
Fenton's Reagent ◽  
Dissolved Air Flotation ◽  
Coagulant Dosage ◽  
Molecular Sizes ◽  
Apparent Colour

This work used Fenton's reagent as a coagulating agent in the treatment of water samples with high true colour caused by humic substances (HS) extracted from peat. In addition, the effects of the apparent molecular size of HS on coagulation, flocculation and flotation were studied. To that end, four distinct water samples having the same true colour were prepared using HS with different molecular sizes, which were obtained by ultrafiltration fractioning. Through optimisation of coagulant dosage and coagulation pH, as well as posterior construction of coagulation diagrams for each water sample, it was verified that the sample prepared with the smallest apparent molecular size of HS was the most difficult to treat, requiring higher coagulant (Fenton's reagent) dosages than samples prepared with larger HS molecular sizes. Furthermore, filtration experiments after dissolved air flotation (DAF) were carried out in an attempt to simulate conventional treatment. The most representative results in filtered water were: apparent colour ≤ 3 HU; turbidity < 0.5 NTU; and residual iron concentration < 0.005 mg/L. The absorbance and total organic carbon values of filtered water samples were also very low, suggesting that the formation of disinfection by-products with chlorine would likely be insignificant.

scholarly journals Research on The Removal of Scale Ions from Circulating Cooling Wastewater by Chemical Coagulation Process

2018 ◽  
Vol 38 ◽  
pp. 02004
Author(s):  
Song Du ◽  
Wenbiao Jin ◽  
Feng Duan
Keyword(s):  
Wastewater Treatment ◽  
Removal Efficiency ◽  
Removal Mechanism ◽  
Chemical Coagulation ◽  
Coagulation Process

In this paper, the circulating cooling wastewater was treated by chemical coagulation process through adding NaOH/Na2CO3.The effect of NaOH and Na2CO3 dose on removal of scale ions, such as Ca2+, Mg2+, Ba2+, Sr2+, SiO2, was studied and the removal mechanism was discussed. The results showed that the increase of NaOH dose was beneficial to the removal of above-mentioned scale ions. When NaOH was only added, the removal efficiency of Ca2+, Mg2+, Ba2+, Sr2+, SiO2 was 86.3%, 91.6%, 86.5%, 58.1%, 84.2%, respectively. When 680 mg/L of NaOH and 300 mg/L of Na2CO3 were added, and the effluent pH was above 11.2, the removal efficiency of Ca2+, Mg2+ was 95.8% and 89.4%, respectively, and the concentration of Ca2+and Mg2+ was below 20 mg/L, which met the target of wastewater treatment. Finally the possible removal mechanism of Ca2+, Mg2+, Ba2+, Sr2+and SiO2 was discussed.

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