Removal of ppb-level DDTs from aqueous solution using organo-diatomites

2013 ◽  
Vol 48 (3) ◽  
pp. 266-278
Author(s):  
Lingzhi Tan ◽  
Shihua Qi ◽  
Jiaquan Zhang ◽  
Xinli Xing ◽  
Wei Chen ◽  
...  
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Contact Angle ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Cetyltrimethylammonium Bromide ◽  
Particle Diffusion ◽  
Initial Concentration ◽  
Homogeneous Particle ◽  
Removal Efficiencies

Three modified organo-diatomites (ODs) were used for removal of o,p′ dichlorodiphenyldichloroethylene (o,p′-DDE), p,p′ dichlorodiphenyldichloroethylene (p,p′-DDE) and p,p′ dichlorodiphenyltrichloroethane (p,p′-DDT) from water. It was found that the adsorption of dichlorodiphenyltrichloroethane (DDT) and its metabolites (DDTs) depended greatly on the type and concentration of modifying agent, the concentration of adsorbent and the initial concentration of DDTs. The hydrophobic characteristics of ODs–DDTs interactions were verified by measuring the amounts of DDTs adsorbed on ODs. The analysis of contact angle and total organic carbon (TOC) measurements revealed that the hydrophilic tails on the ODs surface were replaced with hydrophobic ones by surfactants. The following conditions were strongly suggested to provide the optimum performance for adsorption of DDTs: raw diatomite is modified by cetyltrimethylammonium bromide (CTMAB); dosing quantity of OD is no more than 3.0 g/L. The removal efficiencies of the three pesticides on ODs followed the order: p,p′-DDT > o,p′-DDE > p,p′-DDE. The adsorption efficiencies of ODs for the pesticides followed the order: GZY > GZF > GZYI > GZN. This experiment showed that the fittest models for the experimental data were given by the Redlich–Peterson and homogeneous particle diffusion models.

scholarly journals Vertical In-Vessel Composter for Stabilization of Market Vegetable Waste

2020 ◽  
Vol 9 (3) ◽  
pp. 486-490
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Organic Waste ◽  
Research Work ◽  
Chemical Characteristics ◽  
Vegetable Waste ◽  
Initial Concentration ◽  
Mix Proportion ◽  
Physico Chemical ◽  
Seeding Material

Composting can be one of the solutions to tackle the issue of handling solid waste. In the present research work, a bench-scale vertical in-vessel aerobic composter was designed to stabilize the Devaraja market vegetable waste, Mysore using horse dung and plantain leaves as seeding material and bulking agent respectively. On average, Devaraja market generate 4.8-5.6 ton per day. Mix proportion of organic waste, bulking and seeding materials fed into composter was in the ratio of 5: 1: 0.5. Initial and variation in physico-chemical characteristics of waste were monitored during the composting period. The initial concentration of total nitrogen, phosphorous, total organic carbon and C/N ratio which was found to be 1.67%, 0.78%, 1.93%, 43.5% and 26 showed a variation of 2.4%, 1.1%, 2% 29% and 15 respectively at the end of 21 days of composting.

Artificial neural network (ANN) approach for prediction and modeling of breakthrough curve analysis of fixed-bed adsorption of iron ions from aqueous solution by activated carbon from Limonia acidissima shell

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Shilpi Das ◽  
Susmita Mishra
Keyword(s):  
Neural Network ◽  
Experimental Data ◽  
Aqueous Solution ◽  
Artificial Neural Network ◽  
Activated Carbon ◽  
Packed Bed ◽  
Initial Concentration ◽  
Bed Height ◽  
Artificial Neural Network Ann ◽  
Limonia Acidissima

Abstract The present research article explored the potential of activated carbon prepared from Limonia acidissima shell to adsorb total Fe ions from aqueous solution in a packed bed up-flow column. The effect of essential factors such as bed height (3–5 cm), initial concentration (30–50 mg/L), and flow rate (3.32–5.4 mL/min) on the performance of the column bed was investigated. The adsorption capacity augmented with an increase in bed height and initial adsorbate concentration but declined with an increase in flow rate. The maximum uptake capacity of 209.6 mg/g was achieved at 5 cm bed height, 3.32 mL/min, and 50 mg/L initial concentration. The bed depth service time (BDST) model was used to analyze the experimental data and determine the characteristic parameters of the packed bed reactor suitable for designing large-scale column studies. The Adams–Bohart, Thomas, and Yoon–Nelson models were applied to the experimental data to predict breakthrough curves using non-linear regression. The artificial neural network (ANN) based model was able to efficaciously predict the column performance using the Levenberg–Marquardt (LM) algorithm. A comparison between the experimental data and model results contributed to a high degree of correlation, specifying that the preliminary information was in good agreement with the ANN predicted data.

scholarly journals Tubular nanofiltration of highly concentrated C.I. Acid Black 210 dye

2013 ◽  
Vol 67 (4) ◽  
pp. 901-906 ◽  
Author(s):  
A. Y. Zahrim ◽  
N. Hilal ◽  
C. Tizaoui
Keyword(s):  
Organic Carbon ◽  
Total Organic Carbon ◽  
Dye Removal ◽  
Nanofiltration Membrane ◽  
Solution Ph ◽  
Carbon Removal ◽  
Initial Concentration ◽  
Membrane Performance ◽  
Total Organic Carbon Removal ◽  
Fouling Factor

Tubular nanofiltration membrane performance to treat water for reuse was carried out by choosing C.I. Acid Black 210 dye as a model dye. It has been shown that increasing pH causes reduction in irreversible fouling factor (IFF) and the dye removal is also affected by solution pH. The total organic carbon removal for pH 4, pH 7, pH 8 and pH 10 is 97.9, 92.3, 94.5 and 94.6%, respectively. The conductivity removal for pH 4, pH 7, pH 8 and pH 10 is 85.1, 88.3, 87.8 and 90.7% respectively. The increase in the initial dye concentration causes rapid increase in fouling until 100 mg/l. Then the fouling increases gradually as it reaches a maximum IFF around 13%. This study also shows that the colour of permeate changes from colourless to light greenish/yellowish (initial concentration of 2,000 and 4,000 mg/l) as the initial dye concentration increases. The conductivity removal was also reduced as the initial dye concentration increased due to screening of the Donnan effect with the presence of salt.

Adsorption of 2,4-Dichlorophenoxyacetic Acid from Aqueous Solution Using Carbonized Chest Nut as Low Cost Adsorbent: Kinetic and Thermodynamic

2020 ◽  
Vol 234 (3) ◽  
pp. 461-484
Author(s):  
Jale Gülen ◽  
Sabri Aslan
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Low Cost ◽  
Isotherm Models ◽  
Particle Diffusion ◽  
Dichlorophenoxyacetic Acid ◽  
Adsorption Dynamics ◽  
Intra Particle Diffusion ◽  
Different Temperatures ◽  
2,4 Dichlorophenoxyacetic Acid

AbstractThe activated carbon was made of carbonized chest nut shell (CCS) and used as low cost adsorbent for 2,4-D (2,4-dichlorophenoxyacetic acid) removal. The experiments were conducted at different temperatures such as 35, 45 and 55 °C and this system represents as L type adsorption behavior. The experimental data were modelled using several isotherm models such as Langmuir, Freundlich, Temkin and Dubinin Radushkevich. The adsorption dynamics were searched by applying pseudo first, pseudo second and intra particle diffusion models. The thermodynamic approach was conducted for determining the thermodynamic values of ΔH°, ΔS° and ΔG°.

Removal of total organic carbon from aqueous solution containing polyvinyl alcohol by electrocoagulation technology

Desalination ◽  
2010 ◽  
Vol 259 (1-3) ◽  
pp. 103-110 ◽  
Author(s):  
Wei-Lung Chou ◽  
Chih-Ta Wang ◽  
Chia-Wei Hsu ◽  
Kai-Yu Huang ◽  
Te-Chao Liu
Keyword(s):  
Aqueous Solution ◽  
Organic Carbon ◽  
Polyvinyl Alcohol ◽  
Total Organic Carbon

Photodegradation of chlorpyrifos in water by UV/H2O2 treatment: toxicity evaluation

2013 ◽  
Vol 68 (10) ◽  
pp. 2279-2286 ◽  
Author(s):  
J. Femia ◽  
M. Mariani ◽  
C. Zalazar ◽  
I. Tiscornia
Keyword(s):  
Hydrogen Peroxide ◽  
Organic Carbon ◽  
Total Organic Carbon ◽  
Vibrio Fischeri ◽  
Organophosphorus Pesticide ◽  
Toxicity Evaluation ◽  
H2o2 Treatment ◽  
Initial Concentration ◽  
Total Organic Carbon Analysis ◽  
Carbon Analysis

Chlorpyrifos (CP) is an organophosphorus pesticide widely used in agriculture. Due to its toxicity, it has been necessary to develop a treatment to eliminate the environmental wastes generated by this substance. The combination of UV radiation and hydrogen peroxide seemed an interesting option to reduce the concentration of CP in water, as it has proved to be a simple and effective method to degrade other similar pesticides. The purpose of this work is to study the effect of different initial concentrations of H2O2 on the degradation of commercial CP in water using UV/H2O2. Conversions of 93% were achieved in 20 min with 450 mg L−1 of H2O2 initial concentration (0.16 mg of CP degraded per mg of H2O2 consumed). The total organic carbon analysis showed interesting mineralization values, reaching a 70% conversion after 4 h of reaction. In addition, this degradation procedure leads to a clear reduction of the toxicity of the reaction mixture over Vibrio fischeri.

scholarly journals Adsorption of Rhodamine-B from Aqueous Solution by Activated Carbon from Almond Shell

Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 51 ◽  
Author(s):  
Nasim Abdolrahimi ◽  
Azadeh Tadjarodi
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Rhodamine B ◽  
Langmuir Isotherm ◽  
Adsorption Process ◽  
Ph Value ◽  
Test Results ◽  
Almond Shell ◽  
Initial Concentration ◽  
Removal Efficiencies

The activated carbon was prepared from an almond shell, which is chemically activated by H2SO4. In the present study, the adsorption of rhodamine-B from water by activated carbon has been investigated and compared. The effect of pH value, initial concentration of dissolved and amount of adsorbent on the adsorption of rhodamine-B by the mentioned adsorbents were investigated. Results showed that the adsorption process was highly dependent on pH. Maximum rhodamine-B removal was achieved when the final pH is 11. Maximum rhodamine-B removal efficiencies were obtained by an almond shell (70%). Adsorption test results revealed that rhodamine-B adsorption on the studied adsorbents could be better described by Langmuir isotherm.

scholarly journals Sorption of rare-earth erbium from aqueous solution onto sol-gel-derived zirconia

2016 ◽  
Vol 70 (4) ◽  
pp. 383-390 ◽  
Author(s):  
Nafisa Salem ◽  
Sobhy Yakout
Keyword(s):  
Aqueous Solution ◽  
Rare Earth ◽  
Sol Gel ◽  
Particle Diffusion ◽  
Order Model ◽  
Zirconia Powder ◽  
Erbium Ions ◽  
Homogeneous Particle ◽  
Pseudo Second Order ◽  
Alkaline Range

Zirconia powder was synthesized via sol gel method and used for erbium sorption. The adsorption is strongly dependent on pH of the medium where the removal efficiency increases as the pH turns to alkaline range. The process was very fast initially and maximum adsorption was attained within 60 min of contact. Pseudo-second-order model and homogeneous particle diffusion model (HPDM) was found to be the best to correlate the diffusion of erbium into zirconia particles. Adsorption thermodynamic parameters were calculated. Erbium adsorption is an endothermic (?H > 0) and good affinity of erbium ions towards the zirconia (?S > 0).

scholarly journals Investigation of the Adsorption Potentials of an Organic Adsorbent for Phenol Removal from Aqueous Solution

2021 ◽  
pp. 124-134
Author(s):  
C.E. Muko-Okoro ◽  
I.A. Obiora-Okafo ◽  
J.N. Ndive
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Adsorption Kinetics ◽  
Contact Time ◽  
Phenol Removal ◽  
Initial Concentration ◽  
First Order ◽  
Pseudo Second Order ◽  
Pseudo First Order ◽  
Better Than

Phenol is a prevalent pollutant found in many industrial wastewaters, and it is paid singular attention because of its special features including high toxicity, carcinogenic properties, and vital cumulative ability that affects the health of humans and the environment. The current study investigated the removal of phenol from synthetic aqueous solutions using prepared Moringaoleifera seed shell as an adsorbent. The efficiency of phenol removal by Moringaoleifera seed shell was evaluated in a batch system, and different parameters such as initial concentration of phenol (100, 200, 300, 400 and 500 mg/L), contact time (10, 20, 30, 40, 50 and 60 min), and adsorbent dosage (0.2, 0.4, 0.6, 0.8, and 1.0 g) were studied. The results showed that the highest percentage of phenol removal by the ash occurred at 0.8 g dosage, contact time of 40 min, and initial concentration of 500 mg/L giving 87.2% phenol removal. The adsorption process was modeled with Langmuir and Freundlich isotherms and adsorption kinetics (pseudo-first order and pseudo-second order) at controlled temperatures. The results showed that the experimental data fitted the Langmuir (R2 = 0.8338) much better than the Freundlich model (R2 = 0.7314). For the analysis of the adsorption kinetics, the results showed that the experimental data fitted the pseudo-second order kinetics (R2 = 0.999) much better than the pseudo-first order kinetics (R2 = 0.5042). In general, the results of this study revealed that Moringaoleifera seed shell has suitable potential for use in removing phenol from aqueous solution on operation and practical scales due to its availability and organic nature.

Photocatalytic degradation of methylene blue from aqueous solutions using nanopillars-TiO2 thin films: Batch reactor studies

2018 ◽  
Vol 18 (3) ◽  
pp. 81-91 ◽  
Author(s):  
C. Lalhriatpuia
Keyword(s):  
Thin Films ◽  
Methylene Blue ◽  
Photocatalytic Activity ◽  
Organic Carbon ◽  
Photocatalytic Degradation ◽  
Batch Reactor ◽  
Tio2 Thin Films ◽  
Initial Concentration ◽  
Bet Specific Surface Area ◽  
Interfering Ions

Nanopillars-TiO2 thin films was obtained on a borosilicate glass substrate with (S1) and without (S2) polyethylene glycol as template. The photocatalytic behaviour of S1 and S2 thin films was assessed inthe degradation of methylene blue (MB) dye from aqueous solution under batch reactor operations. The thin films were characterized by the SEM, XRD, FTIR and AFM analytical methods. BET specific surface area and pore sizes were also obtained. The XRD data confirmed that the TiO2 particles are in its anatase mineral phase. The SEM and AFM images indicated the catalyst is composed with nanosized pillars of TiO2, evenly distributed on the surface of the substrate. The BET specific surface area and pore sizes of S1 and S2 catalyst were found to be 5.217 and 1.420 m2/g and 7.77 and 4.16 nm respectively. The photocatalytic degradation of MB was well studied at wide range of physico-chemical parameters. The effect of solution pH (pH 4.0 to 10.0) and MB initial concentration (1.0 to 10.0 mg/L) was extensively studied and the effect of several interfering ions, i.e., cadmium nitrate, copper sulfate, zinc chloride, sodium chloride, sodium nitrate, sodium nitrite, glycine, oxalic acid and EDTA in the photocatalytic degradation of MB was demonstrated. The maximum percent removal of MB was observed at pH 8.0 beyond which it started decreasing and a low initial concentration of the pollutant highly favoured the photocatalytic degradation using thin films and the presence of several interfering ions diminished the photocatalytic activity of thin films to some extent. The overall photocatalytic activity was in the order: S2 > S1 > UV. The photocatalytic degradation of MB was followed the pseudo-first-order rate kinetics. The mineralization of MB was studied with total organic carbon measurement using the TOC (total organic carbon) analysis.

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