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.

Textile Wastewater Treatment Using Sodom Apple (Calotropis procera) - Aided Tamarind Seed as a Coagulant

2017 ◽  
Vol 32 ◽  
pp. 76-85
Author(s):  
Saidat Olanipekun Giwa ◽  
Danladi Yakubu Said ◽  
Mustapha Danladi Ibrahim ◽  
Abdulwahab Giwa
Keyword(s):  
Removal Efficiency ◽  
Mixing Time ◽  
Textile Wastewater ◽  
Calotropis Procera ◽  
Colour Removal ◽  
Jar Test ◽  
Tamarind Seed ◽  
Coagulant Dosage ◽  
Sodom Apple ◽  
Total Dissolved Solid

Water contamination seems unavoidable as many human activities involve the use of water in one way or the other. Chemical coagulants, especially aluminium based, which are widely used in treatment of wastewater or contaminated water have been associated with some health issues. Research on the use of plant based coagulants in water treatment now draws a lot of attentions, not only because the natural coagulants are presumed safe but also because of their biodegradable nature. In this present study, efforts have been made to evaluate the effectiveness of locally available tamarind seed powder as natural coagulant and Sodom apple (Calotropis procera) as coagulant aid for the treatment of textile wastewater. The tests were carried out using the conventional jar test apparatus at various pH and coagulant dosage with no aid added. Also, three sets of jar test experiments were performed at constant values of coagulant dosage and pH (which were found to be favourable in the first experiments) by varying the dosage of liquid and solid coagulant aid as well as time. The results obtained show that pH slightly affected the pollutants removal efficiency of the unaided coagulation. The neutral pH was found to be favourable with turbidity and colour removal of 22.25% and 30.36% respectively. The optimum mixing time of turbidity removal efficiency was found to be 2 min with rapid mixing of 30 seconds and 1½ min of slow mixing with turbidity and colour removal of 69.48% and 60.53% respectively. The optimum dosage was found to be 4.0 g of coagulant and 1.0 g of coagulant aid for turbidity, total dissolved solid and colour removal efficiency.

Removal of sulphite-reducing clostridia spores by full-scale water treatment processes as a surrogate for protozoan (oo)cysts removal

2000 ◽  
Vol 41 (7) ◽  
pp. 165-171 ◽  
Author(s):  
W. A. Hijnen ◽  
J. Willemsen-Zwaagstra ◽  
P. Hiemstra ◽  
G. J. Medema ◽  
D. van der Kooij
Keyword(s):  
Water Treatment ◽  
Removal Efficiency ◽  
Water Quality Monitoring ◽  
Full Scale ◽  
Process Conditions ◽  
Safe Drinking Water ◽  
Unit Process ◽  
Treatment Processes ◽  
Scale Unit ◽  
Micro Organisms

At eight full-scale water treatment plants in the Netherlands the removal of spores of sulphite-reducing clostridia (SSRC) was determined. By sampling and processing large volumes of water (1 up to 500 litres) SSRC were detected after each stage of the treatment. This enabled the assessment of the removal efficiency of the full-scale unit processes for persistent micro-organisms. A comparison with literature data on the removal of Cryptosporidium and Giardia by the same type of processes revealed that SSRC can be considered as a potential surrogate. The average Decimal Elimination Capacity (DEC) of the overall treatment plants ranged from 1.3–4.3 log. The observed actual log removal of SSRC by the unit processes and the overall treatment at one of the studied locations showed that the level of variation in removal efficiency was approximately 2 log. Moreover, from the actual log removal values it was observed that a low SSRC removal by one unit process is partly compensated by a higher removal by subsequent unit processes at this location. SSRC can be used for identification of the process conditions that cause variation in micro-organism removal which may lead to process optimization. Further research is necessary to determine the optimal use of SSRC in water quality monitoring for the production of microbiologically safe drinking water.

Post-treatment of sanitary landfill leachate by coagulation–flocculation using chitosan as primary coagulant

2016 ◽  
Vol 74 (1) ◽  
pp. 246-255 ◽  
Author(s):  
Inara Oliveira do Carmo Nascimento ◽  
Ana Rosa Pinto Guedes ◽  
Louisa Wessels Perelo ◽  
Luciano Matos Queiroz
Keyword(s):  
Acute Toxicity ◽  
Removal Efficiency ◽  
Landfill Leachate ◽  
Post Treatment ◽  
Toxicity Tests ◽  
Process Conditions ◽  
Sanitary Landfill ◽  
Average Growth ◽  
Acute Toxicity Tests ◽  
Sanitary Landfill Leachate

Chitosan was chosen as an alternative primary coagulant in a complementary coagulation–flocculation treatment of sanitary landfill leachate with the aim of removing recalcitrant organic matter. In order to optimize the process conditions, central composite design and response surface methodology were applied. To evaluate the performance of the process using chitosan, we also carried out tests with aluminium sulphate (Al2 (SO4)3.14 H2O) as coagulant. In addition, acute toxicity tests were carried using the duckweed Lemna minor and the guppy fish Poecilia reticulata as test organisms. The analytic hierarchy process was employed for selecting the most appropriate coagulant. Mean values of true colour removal efficiency of 80% and turbidity removal efficiency of 91.4% were reached at chitosan dosages of 960 mg L−1 at pH 8.5. The acute toxicity tests showed that organisms were sensitive to all samples, mainly after coagulation–flocculation using chitosan. CE50 for L. minor was not determined because there was no inhibition of the average growth rate and biomass production; LC50 for P. reticulata was 23% (v v−1). Multi-criteria analysis showed that alum was the most appropriate coagulant. Therefore, chitosan as primary coagulant was not considered to be a viable alternative in the post-treatment of landfill leachate.

scholarly journals Multivariate Optimization of Pb2+ Adsorption onto Ethiopian Low-Cost Odaracha Soil Using Response Surface Methodology

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6477
Author(s):  
Yohanis Birhanu ◽  
Seyoum Leta
Keyword(s):  
Central Composite Design ◽  
Response Surface ◽  
Removal Efficiency ◽  
Interaction Effect ◽  
Contact Time ◽  
Low Cost ◽  
Design Model ◽  
Lead Ions ◽  
Experimental Result ◽  
Central Composite

Lead pollution is a severe health concern for humankind. Utilizing water contaminated with lead can cause musculoskeletal, renal, neurological, and fertility impairments. Therefore, to remove lead ions, proficient, and cost-effective methods are imperative. In this study, the Odaracha soil which is traditionally used by the local community of the Saketa District was used as a novel low-cost technology to adsorb lead ions. Odaracha adsorbent was characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. The adsorption process followed the batch adsorption experiment. The response surface method was implemented to derive the operating variables’ binary interaction effect and optimize the process. According to the study’s experimental result, at optimum experimental conditions Odaracha adsorbent removes 98.17% of lead ions. Based on the result of the central composite design model, the Pb2+ ion removal efficiency of Odaracha was 97.193%, indicating an insignificant dissimilarity of the actual and predicted results. The coefficient of determination (R2) for Pb2+ was 0.9454. According to the factors’ influence indicated in the results of the central composite design model, all individual factors and the interaction effect between contact time and pH has a significant positive effect on lead adsorption. However, other interaction effects (contact time with dose and pH with dose) did not significantly influence the removal efficiency of lead ions. The adsorption kinetics were perfectly fitted with a pseudo-second-order model, and the adsorption isotherm was well fitted with the Freundlich isotherm model. In general, this study suggested that Odaracha adsorbent can be considered a potential adsorbent to remove Pb2+ ions and it is conceivable to raise its effectiveness by extracting its constituents at the industrial level.

scholarly journals Evaluation of bio-coagulants for colour removal from dye synthetic wastewater: characterization, adsorption kinetics, and modelling approach

Water SA ◽  
2020 ◽  
Vol 46 (2 April) ◽  
Author(s):  
IA Obiora-Okafo ◽  
OD Onukwuli ◽  
NC Eli-Chukwu
Keyword(s):  
Adsorption Kinetics ◽  
Molecular Layer ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Synthetic Wastewater ◽  
Organic Polymer ◽  
Good Prediction ◽  
Colour Removal ◽  
Separation Processes ◽  
Coagulant Dosage

Dye usage for industrial applications has been on the increase and these activities generate large amounts of dye-constituted wastewater that should be treated before environmental discharge or reuse. Various studies have shown the application of natural organic polymer (NOP) coagulants in dye removal from industrial wastewater. In this research, the coagulation performances of Vigna unguiculata (VU) and Telfairia occidentalis (TO) for colour removal from crystal Ponceau 6R dye synthetic wastewater was studied. The proximate compositions, structure, and surface morphologies of the coagulants were investigated using standard methods, i.e. Fourier-Transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM). Colour removal was evaluated through the time-dependent decrease in particle concentration and thus growth of flocs. Effects of the process parameters, including pH, coagulant dosage, dye concentration (DC), settling time, and temperature were preliminarily tested and the best range experimentally determined. The optimal operating conditions established were pH 2, 800 mg∙L−1 coagulant dosage, 100 mg∙L−1 dye concentration, 300 min, and 303 K. The order of greatest removal was VUC > TOC with optimum efficiency of 93.5% and 90.7%, respectively. The values of K and α obtained for VUC and TOC were 8.09 x 10−4 L∙mg−1∙min−1, 1.7 and 9.89 x 10-4 L∙mg−1∙min−1, 1.6, respectively. Coagulation time, Tag, calculated and deduced from the particle distribution plot, showed a rapid coagulation process. Coagulation-adsorption kinetics indicated agreement with the pseudo-second-order model deducing that chemisorption is the rate-controlling step. It further indicates that particle adsorption on the polymer surfaces occurred mostly as a mono-molecular layer and according to the chemisorption mechanism. Cross-validation showed good prediction of the experimental data. The selected coagulants have the potential for application as efficient coagulants while also showing significant adsorption characteristics. The application of kinetics and modelling in separation processes involving particle transfer is especially required in wastewater treatment.

Optimization of a Whole-Stalk Operating System after Sugarcane Base Cutting

2019 ◽  
Vol 62 (1) ◽  
pp. 157-166
Author(s):  
Luxin Xie ◽  
Jun Wang ◽  
Shaoming Cheng ◽  
Jinbing Hu
Keyword(s):  
Operating System ◽  
Response Surface Methodology ◽  
Central Composite Design ◽  
Response Surface ◽  
Fracture Rate ◽  
Cleaning Performance ◽  
Abrasion Rate ◽  
Leaf Stripping ◽  
Predicted Values ◽  
Central Composite

Abstract. Leaf stripping and top breaking are the key procedures in whole-stalk sugarcane harvesting. In this study, a whole-stalk operating system after sugarcane base cutting was developed and tested to improve the leafy trash cleaning performance and adaptability of a whole-stalk harvester. A leaf shredding procedure was proposed before leaf stripping, and an anti-float top breaking device was developed for breaking cane tops. The rotational speeds of the leaf shredding (RL), leaf stripping (RS), and top breaking (RT) rollers were regarded as experimental factors, and the leafy trash content (including leaves, leaf sheaths, and tops in this study), top breaking rate, abrasion rate, and non-fracture rate of the middle or bottom parts were selected as indices. Central composite design combined with response surface methodology and comprehensive evaluation method were employed to conduct experiments and explore the interaction effects of factors on indices. The optimal operating parameters were nonlinearly optimized and determined to be RL of 512.9 rpm, RS of 418.8 rpm, and RT of 307.0 rpm. Under these conditions, the predicted values of leafy trash content, top breaking rate, abrasion rate, and non-fracture rate were 4.98%, 88.39%, 5.19%, and 96.21%, respectively. Verification experiments indicated that the observed values were in agreement with the predicted values. Results suggested that the leaf shredding device and anti-float top breaking device developed in this study were effective for improving the leafy trash cleaning performance and adaptability of the whole-stalk operating system, and there was a good potential for performance improvement of whole-stalk sugarcane harvesters. Keywords: Central composite design, Leaf shredding, Leaf stripping, Response surface methodology, Top breaking, Whole-stalk harvester.

scholarly journals Effect of Electron Beam Method on Processing of Titanium Technogenic Material

Metals ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 683 ◽  
Author(s):  
Katia Vutova ◽  
Vania Vassileva ◽  
Vladislava Stefanova ◽  
Dinesh Amalnerkar ◽  
Takeshi Tanaka
Keyword(s):  
Electron Beam ◽  
Removal Efficiency ◽  
Beam Power ◽  
Melting Time ◽  
Process Conditions ◽  
Technological Parameters ◽  
Electron Beam Processing ◽  
Composition Variation ◽  
High Level

This study reveals the efficiency of the electron beam processing of titanium technogenic material with a high level of impurities and the quality of the obtained metal in correlation to process parameters which are discussed. The influence of the beam power and melting time on the composition variation, morphologies, hardness of metal samples and mass losses is investigated. Based on the different technological parameters, the removal efficiency of impurities is also discussed, and the corresponding experiments are carried out in order to make a comparison. Different thermal process conditions are realized during the single-melt operation. Chemical and metallographic analyses are performed, and the results are discussed. The hardness of the titanium decreases by prolonging the time of the electron beam processing. A maximal overall removal efficiency of 99.975% is seen at 5.5 kW beam power for a 40 min melting time and the best purification of Ti (99.996%) is achieved.

Modeling and Optimization of Poly Electrolyte Dosage in Water Treatment Process by GMDH Type- NN and MOGA

2013 ◽  
Vol 3 (2) ◽  
pp. 94-106 ◽  
Author(s):  
M. Akbarizadeh ◽  
A. Daghbandan ◽  
M. Yaghoobi
Keyword(s):  
Genetic Algorithms ◽  
Water Treatment ◽  
Treatment Process ◽  
Data Sets ◽  
Raw Water ◽  
Multi Objective ◽  
Water Treatment Process ◽  
Coagulant Dosage ◽  
Predicted Values ◽  
Experimental Values

Coagulation-flocculation is the most important parts of water treatment process. Traditionally, optimum pre coagulant dosage is determined by used jar tests in laboratory. However; jar tests are time-consuming, expensive, and less adaptive to changes in raw water quality in real time. Soft computing can be used to overcome these limitations. In this paper, multi-objective evolutionary Pareto optimal design of GMDH Type-Neural Network has been used for modeling and predicting of optimum poly electrolyte dosage in Rasht WTP, Guilan, Iran, using Input - output data sets. In this way, multi-objective uniform-diversity genetic algorithms (MUGA) are then used for Pareto optimization of GMDH networks. In order to achieve this modeling, the experimental data were divided into train and test sections. The predicted values were compared with those of experimental values in order to estimate the performance of the GMDH network. Also, Multi Objective Genetic Algorithms (MOGA) are then used for optimization of influence parameters in pre coagulant (Poly electrolyte) dosage.

Sign in / Sign up

Export Citation Format

Share Document