scholarly journals Aqueous Mercury Removal with Carbonaceous and Iron Sulfide Sorbents and Their Applicability as Thin-Layer Caps in Mercury-Contaminated Estuary Sediment

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1991 ◽  
Author(s):  
Boon-Lek Ch’ng ◽  
Che-Jung Hsu ◽  
Yu Ting ◽  
Ying-Lin Wang ◽  
Chi Chen ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Thin Layer ◽  
Removal Efficiency ◽  
Iron Sulfide ◽  
Aqueous System ◽  
Batch Adsorption ◽  
Overlying Water ◽  
Salinity Levels ◽  
Microcosm Studies ◽  
Aqueous Mercury

This study aimed to investigate the Hg removal efficiency of iron sulfide (FeS), sulfurized activated carbon (SAC), and raw activated carbon (AC) sorbents influenced by salinity and dissolved organic matter (DOM), and the effectiveness of these sorbents as thin layer caps on Hg-contaminated sediment remediation via microcosm experiments to decrease the risk of release. In the batch adsorption experiments, FeS showed the greatest Hg2+ removal efficiencies, followed by SAC and AC. The effect of salinity levels on FeS was insignificant. In contrast, the Hg2+ removal efficiency of AC and SAC increased as increasing the salinity levels. The presence of DOM tended to decrease Hg removal efficiency of sorbents. Microcosm studies also showed that FeS had the greatest Hg sorption in both freshwater and estuary water; furthermore, the methylmercury (MeHg) removal ability of sorbents was greater in the freshwater than that in the estuary water. Notably, for the microcosms without capping, the overlying water MeHg in the estuary microcosm (0.14−1.01 ng/L) was far lesser than that in the freshwater microcosms (2.26−11.35 ng/L). Therefore, Hg compounds in the freshwater may be more bioavailable to microorganisms in methylated phase as compared to those in the estuary water. Overall, FeS showed the best Hg removal efficiency, resistance to salinity, and only slightly affected by DOM in aqueous adsorption experiments. Additionally, in the microcosms, AC showed as the best MeHg adsorber that help inhibiting the release of MeHg into overlying and decreasing the risk to the aqueous system.

scholarly journals Reactive Black 5 (RB5): Pengolahan Air Limbah Tekstil dengan Adsorbsi Menggunakan Powdered Karbon Aktif

2021 ◽  
Vol 22 (2) ◽  
pp. 199-205
Author(s):  
Iva Yenis Septiariva ◽  
I Wayan Koko Suryawan ◽  
Ariyanti Sarwono
Keyword(s):  
Activated Carbon ◽  
Removal Efficiency ◽  
Langmuir Isotherm ◽  
Adsorption Process ◽  
Color Removal ◽  
Coefficient Of Determination ◽  
Batch Adsorption ◽  
Maximum Adsorption Capacity ◽  
Reactive Black 5 ◽  
Synthetic Dyes

ABSTRAK Umumnya, industri tekstil menggunakan berbagai pewarna sintetis yang menghasilkan air limbah yang sangat berwarna. Oleh karenaitu, air limbah tekstil ini harus diolah sebelum dibuang ke lingkungan. Penelitian ini bertujuan untuk mengetahui penyisihan warna dengan teknik adsorpsi menggunakan karbon aktif. Metode ini dianggap sebagai teknologi berbiaya rendah dan perawatan yang mudah untuk pengolahan air limbah. Proses adsorpsi batch dilakukan dengan waktu kontak yang berbeda yaitu 5–60 menit dan variasi konsentrasi awal yang mengandung Reactive Black 5 (RB-5) sebesar 5 mg/L; 10 mg/L; 15 mg/L; dan 20 mg/L. Azo-Reactive Black-5 adalah material pewarna yang digunakan untuk membuat air limbah artifisial. Hasil penelitian menunjukkan bahwa proses adsorpsi menurunkan kadar konsentrasi warna masing-masing sebesar 86,21%, 85,21%, 84,29%, dan 71,07% selama 60 menit. Peningkatan konsentrasi zat warna dalam air limbah menyebabkan efisiensi penghilangan warna yang rendah. Selain itu, penelitian mengevaluasi efektivitas adsorpsi batch oleh karbon aktif karena efisiensi penghilangan warna dapat mencapai lebih dari 50% setelah waktu kontak 30 menit. Hal ini terlihat pada konsentrasi awal 5 mg/L dan 20 mg/L dengan efisiensi penyisihan sebesar 66,18% dan 53,97%. Kinetika adsorpsi yang sesuai untuk pendekatan pemodelan pada penelitian ini adalah Langmuir isotherm dengan nilai r2 yang lebih besar dan mendekati nilai 1 yaitu 0,9756. Estimasi kapasitas adsorpsi maksimum yang diperoleh dari model sebesar 4,353 mg/g. Kata kunci: Air limbah tekstil, warna, adsorpsi, efisiensi penyisihan   ABSTRACT Generally, the textile industry uses various synthetic dyes that produced a large amount of highly colored wastewater. This research aims to investigate the color removal by adsorption using powdered activated carbon. This method is considered viable due to cost effective and ease of maintenance for wastewater treatment. The batch adsorption process was carried out at different contact times of 5–60 minutes and varied initial dye concentration containing azo-Reactive Black 5 (RB-5) of 5 mg/L; 10 mg/L; 15 mg/L; and 20 mg/L. A synthetic RB-5 was prepared  as the artificial wastewater to simulate the actual wastewater. The adsorption  proceeded initially with higher rates and gradually slowed down until reached a constant value due to the carbon surface's saturation with increasing contact time.The results showed that, at different initial dye concentration, the adsorption process decreased color concentration for 60 minutes by 86.21%, 85.21%, 84.29%, and 71.07% respectively. The increase of initial dye concentration lowers color removal efficiency. Besides, the effectiveness of adsorption by activated carbon was found more than 50% after 30 minute of contact time. The efficiency removal presented initial concentration of 5 mg/ and 20 mg/L was 66.18% and 53.97%, respectively. Langmuir and Freundlich isotherm were also plotted to assess the kinetics of adsorption. Langmuir isotherm gave the best modelling approach for adsorption kinetics as indicated by higher coefficient of determination (r2) of 0.9756. An estimated maximum adsorption capacity obtained from the model was 4.353 mg/g. Keywords: Textile wastewater, color, adsorption, removal efficiency

Removal of Colour from Waste Water Using Coconut Shell Activated Carbon (CSAC) and Commercial Activated Carbon (CAC)

2013 ◽  
Vol 60 (1) ◽  
Author(s):  
Mohammed Jibril ◽  
Jaafar Noraini ◽  
Lai Shiou Poh ◽  
Abdullahi Mohammed Evuti
Keyword(s):  
Waste Water ◽  
Activated Carbon ◽  
Removal Efficiency ◽  
Color Removal ◽  
Coconut Shell ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Colour Removal ◽  
Initial Color ◽  
Coconut Shell Activated Carbon

Dalam kajian ini, satu siri eksperimen penjerapan berkelompok telah dijalankan untuk menyiasat kecekapan penyingkiran warna oleh CSAC dan CACs daripada air sisa. Kecekapan penjerapan telah dinilai dengan mengukur peratus penyingkiran warna. Kesan larutan pH, kepekatan adsorben, masa betindak balas dan kepekatan warna asal terhadap kecekapan penyingkiran warna juga telah disiasat. Penjerapan warna optimum dicapai pada pH rendah (pH 1.68), kepekatan warna asal yang rendah (50mg/l) dan 12g/l dos karbon dengan kecekapan penyingkiran sebanyak 75% untuk CAC dan 45% bagi CSAC, dengan pergolakan selama satu jam. Kecekapan penyingkiran warna yang rendah iaitu 25% untuk CAC dan 17% untuk CSAC telah diperoleh pada pH tinggi (ph 9-12), kepekatan warna asal yang tinggi iaitu 100mg/l dan dos karbon yang rendah untuk tempoh penahanan yang sama. Perbandingan antara model isotherm Langmuir dan Freundlich ke atas data penjerapan menunjukkan bahawa model isotermal Langmuir menunjukkan keputusan yang lebih baik dengan pekali korelasi, R2 yang lebih tinggi. Keputusan menunjukkan bahawa CSAC boleh digunakan sebagai alternatif kos rendah untuk CAC untuk menyingkirkan pewarna daripada air sisa tetapi kecekapannya penyingkirannya adalah lebih rendah berbanding CAC. Kata kunci: Warna pengeluaran; air sisa; arang batu; kelapa shell; karbon teraktif; Adsorpsi sesuhu In this study, series of batch adsorption experiment were conducted to examine the color removal efficiency of CSAC and CACs from waste water. The CAC is coal base activated carbon while the CSAC was manufactured in the laboratory. Yellow dye colour (Tartrazine E102) was utilized as the colourant. The adsorption efficiencies of the adsorbents were evaluated and compared by measuring the percentage of color removed. The effects of solution pH, adsorbent concentration, contact time as well as initial color concentration on the colour removal efficiency were also investigated. The optimum adsorption of color was achieved at low pH (pH 1.68), low initial color concentration (50mg/L) and 12g/l carbon dosage with removal efficiency of 75% for CAC and 45% for CSAC, with one hour agitation. Lower colour removal efficiency of 25% for CAC and 17% for CSAC were obtained at higher pH (pH 9-12), higher initial color concentration (100mg/L) and low carbon dosage, under the same retention time. A comparison of the Langmuir and Freundlich isotherm models of the adsorption data shows that Langmuir isotherm shows higher correlation coefficient, R2. The results indicate that CSAC has the potential as a low cost alternative for colour removal but the efficiency is lower than CSAC. Keywords: Color removal; waste water; coal; coconut shell; activated carbon; adsorption isotherm

Utilisation of Biomass and Hybrid Biochar from Elephant Grass and Low Density Polyethylene for the Competitive Adsorption of Pb(II), Cu(II), Fe(II) and Zn(II) from Aqueous Media

2020 ◽  
Vol 13 ◽  
Author(s):  
Joshua O. Ighalo ◽  
Lois T. Arowoyele ◽  
Samuel Ogunniyi ◽  
Comfort A. Adeyanju ◽  
Folasade M. Oladipo-Emmanuel ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Removal Efficiency ◽  
Contact Time ◽  
Competitive Adsorption ◽  
Adsorption Process ◽  
Aqueous Media ◽  
Polluted Water ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Elephant Grass

Background: The presence of pollutants in polluted water is not singularized hence pollutant species are constantly in competition for active sites during the adsorption process. A key advantage of competitive adsorption studies is that it informs on the adsorbent performance in real water treatment applications. Objective: This study aims to investigate the competitive adsorption of Pb(II), Cu(II), Fe(II) and Zn(II) using elephant grass (Pennisetum purpureum) biochar and hybrid biochar from LDPE. Method: The produced biochar was characterised by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The effect of adsorption parameters, equilibrium isotherm modelling and parametric studies were conducted based on data from the batch adsorption experiments. Results: For both adsorbents, the removal efficiency was >99% over the domain of the entire investigation for dosage and contact time suggesting that they are very efficient for removing multiple heavy metals from aqueous media. It was observed that removal efficiency was optimal at 2 g/l dosage and contact time of 20 minutes for both adsorbent types. The Elovich isotherm and the pseudo-second order kinetic models were best-fit for the competitive adsorption process. Conclusion: The study was able to successfully reveal that biomass biochar from elephant grass and hybrid biochar from LDPE can be used as effective adsorbent material for the removal of heavy metals from aqueous media. This study bears a positive implication for environmental protection and solid waste management.

scholarly journals Removal of organic pollutants from produced water by batch adsorption treatment

2021 ◽  
Author(s):  
Eman Hashim Khader ◽  
Thamer Jassim Mohammed ◽  
Nourollah Mirghaffari ◽  
Ali Dawood Salman ◽  
Tatjána Juzsakova ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Produced Water ◽  
Oxygen Demand ◽  
Powdered Activated Carbon ◽  
Pollutant Removal ◽  
Operating Conditions ◽  
Isotherm Models ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Zeolite X

AbstractThis paper studied the adsorption of chemical oxygen demand (COD), oil and turbidity of the produced water (PW) which accompanies the production and reconnaissance of oil after treating utilizing powdered activated carbon (PAC), clinoptilolite natural zeolite (CNZ) and synthetic zeolite type X (XSZ). Moreover, the paper deals with the comparison of pollutant removal over different adsorbents. Adsorption was executed in a batch adsorption system. The effects of adsorbent dosage, time, pH, oil concentration and temperature were studied in order to find the best operating conditions. The adsorption isotherm models of Langmuir, Freundlich and Temkin were investigated. Using pseudo-first-order and pseudo-second-order kinetic models, the kinetics of oil sorption and the shift in COD content on PAC and CNZ were investigated. At a PAC adsorbent dose of 0.25 g/100 mL, maximum oil removal efficiencies (99.57, 95.87 and 99.84 percent), COD and total petroleum hydrocarbon (TPH) were identified. Moreover, when zeolite X was used at a concentration of 0.25 g/100 mL, the highest turbidity removal efficiency (99.97%) was achieved. It is not dissimilar to what you would get with PAC (99.65 percent). In comparison with zeolites, the findings showed that adsorption over PAC is the most powerful method for removing organic contaminants from PW. In addition, recycling of the consumed adsorbents was carried out in this study to see whether the adsorbents could be reused. Chemical and thermal treatment will effectively regenerate and reuse powdered activated carbon and zeolites that have been eaten. Graphic abstract

scholarly journals Comparative studies on the removal of copper (II) by Ulva fasciata activated carbon and commercially activated carbon

2012 ◽  
Vol 14 (4) ◽  
pp. 88-94 ◽  
Author(s):  
R.P. Suresh Jeyakumar ◽  
V. Chandrasekaran
Keyword(s):  
Activated Carbon ◽  
Activated Carbons ◽  
Synthetic Wastewater ◽  
Batch Adsorption ◽  
First Order ◽  
Ulva Fasciata ◽  
Adsorption Data ◽  
Pseudo Second Order ◽  
Pseudo First Order ◽  
Adsorbent Dose

Abstract In this work, the efficiency of Ulva fasciata sp. activated carbons (CCUC, SCUC and SSUC) and commercially activated carbon (CAC) were studied for the removal of Cu (II) ions from synthetic wastewater. Batch adsorption experiments were carried out as a function of pH, contact time, initial copper concentration and adsorbent dose. The percentage adsorption of copper by CCUC, SSUC, SCUC and CAC are 88.47%, 97.53%, 95.78% and 77.42% respectively. Adsorption data were fitted with the Langmuir, Freundlich and Temkin models. Two kinetic models pseudo first order and the pseudo second order were selected to interpret the adsorption data.

Estimation of Dioxins Removal Efficiency by Activated Carbon.

2004 ◽  
Vol 30 (1) ◽  
pp. 54-64 ◽  
Author(s):  
Michitaka FURUBAYASHI ◽  
Kenichi NAGAI
Keyword(s):  
Activated Carbon ◽  
Removal Efficiency

Granular activated carbon (GAC) adsorption in tertiary wastewater treatment: experiments and models

2003 ◽  
Vol 47 (1) ◽  
pp. 113-120 ◽  
Author(s):  
D.S. Chaudhary ◽  
S. Vigneswaran ◽  
V. Jegatheesan ◽  
H.H. Ngo ◽  
H. Moon ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Carbon ◽  
Fixed Bed ◽  
Granular Activated Carbon ◽  
Developed Countries ◽  
Synthetic Wastewater ◽  
Batch Adsorption ◽  
Model Parameters ◽  
Wide Range ◽  
Gac Adsorption

Wastewater treatment has always been a major concern in the developed countries. Over the last few decades, activated carbon adsorption has gained importance as an alternative tertiary wastewater treatment and purification process. In this study, granular activated carbon (GAC) adsorption was evaluated in terms of total organic carbon (TOC) removal from low strength synthetic wastewater. This paper provides details on adsorption experiments conducted on synthetic wastewater to develop suitable adsorption isotherms. Although the inorganics used in the synthetic wastewater solution had an overall unfavourable effect on adsorption of organics, the GAC adsorption system was found to be effective in removing TOC from the wastewater. This study showed that equation of state (EOS) theory was able to fit the adsorption isotherm results more precisely than the most commonly used Freundlich isotherm. Biodegradation of the organics with time was the most crucial and important aspect of the system and it was taken into account in determining the isotherm parameters. Initial organic concentration of the wastewater was the determining factor of the model parameters, and hence the isotherm parameters were determined covering a wide range of initial organic concentrations of the wastewater. As such, the isotherm parameters derived using the EOS theory could predict the batch adsorption and fixed bed adsorption results of the multi-component system successfully. The isotherm parameters showed a significant effect on the determination of the mass transfer coefficients in batch and fixed bed systems.

Sign in / Sign up

Export Citation Format

Share Document