scholarly journals Pengaruh Waktu Proses pada Desalinasi Air Laut dengan Metode Elektrokoagulasi secara Batch

FLUIDA ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 65-72
Author(s):  
Rifki Ardiansyah ◽  
Triyoga Meiditama Putra ◽  
Dian Ratna Suminar ◽  
Agustinus Ngatin
Keyword(s):  
Processing Time ◽  
Raw Material ◽  
Process Time ◽  
Iron Electrodes ◽  
Processing Times ◽  
Fe Content ◽  
Electrocoagulation Process ◽  
Aluminum Electrodes ◽  
A Current ◽  
Better Than

ABSTRAK Salah satu upaya untuk menjaga persediaan air yaitu dengan cara menurunkan parameter air laut agar memenuhi parameter air tawar menggunakan metode elektrokoagulasi. Penelitian ini bertujuan untuk mempelajari pengaruh waktu proses elektrokoagulasi terhadap penurunan TDS, kekeruhan, kadar Cl, dan kadar Fe. Selain itu, untuk mengetahui perbandingan antara elektroda Al dan Fe. Air laut diambil dari Pantai Pelabuhan Ratu. Elektroda yang digunakan adalah Al dan Fe dengan ukuran 15x10 cm2. Tegangan yang digunakan yaitu 5 volt atau rapat arus sebesar 0,137 A/dm2 dengan waktu proses 15, 30, 45, dan 60 menit serta volume bahan bakunya 4 Liter. Penelitian dengan waktu proses 30 menit dan proses pengendapan selama satu hari mampu menurunkan kekeruhan hingga 2,28 NTU (55,07%); TDS hingga 1.010 mg/L (3,71%); kadar Cl hingga 271,98 mg/L (3,52%); dan kadar Fe 0,05 mg/L (40,65%). Proses elektrokoagulasi menggunakan elektroda aluminium lebih baik dibandingkan elektroda besi pada waktu proses 30 menit.   ABSTRACT One of the efforts to maintain water supply is by lowering seawater parameters to meet freshwater parameters using the electrocoagulation method. This study aims to study the effect of electrocoagulation process time on the decrease in TDS, turbidity, Cl content, and Fe content. In addition, to determine the comparison between Al and Fe electrodes. Seawater is taken from Pelabuhan Ratu Beach. The electrodes used are Al and Fe with a size of 15x10 cm2. The voltage used is 5 volts or a current density of 0,137 A/dm2 with processing times of 15, 30, 45, and 60 minutes and the volume of the raw material is 4 liters. Research with a processing time of 30 minutes and sedimentation for one day was able to reduce turbidity up to 2,28 NTU (55,07%); TDS up to 1.010 mg/L (3,71%); Cl content up to 271,98 mg/L (3,52%); and Fe content of 0,05 mg/L (40,65%). The electrocoagulation process using aluminum electrodes was better than iron electrodes at a processing time of 30 minutes.

scholarly journals Effect of various parameters in removing Cr and Ni from model wastewater by using electrocoagulation

2013 ◽  
Vol 15 (4) ◽  
pp. 494-503 ◽  
Keyword(s):  
Removal Rate ◽  
Initial Value ◽  
Effective Surface ◽  
Initial Concentration ◽  
Iron Electrodes ◽  
Electrode Combination ◽  
Initial Ph ◽  
Electrocoagulation Process ◽  
Aluminum Electrodes ◽  
A Current

<p>The performance of a laboratory scale electrocoagulation system for the removal of Cr and Ni from model wastewater was studied systematically using iron and aluminum electrodes with an effective surface area of 13.8 cm2 and a distance of 4 cm. The influence of several parameters, such as initial concentration, electrode combination, current supply and initial pH was investigated during electrocoagulation process. The increase in initial concentration favored removal rate, did not affect nickel removal, but restricted chromium removal, thus indicating its required mechanism of reducing hexavalent ion to trivalent. The best removal efficiency, when metals existed separately in treated solutions, was accomplished with the use of iron electrodes for Cr (50%) and with aluminum electrodes for Ni (90%). When metals co-existed, iron electrodes achieved the best result, which was 76% for Cr and 82% for Ni, leaving 30 mg l-1 and 17 mg l-1 of residual concentrations, respectively, after 180 min of treatment. Solutions&rsquo; nominal pH appeared to be optimal, since increasing or decreasing their initial value did not benefit the electrocoagulation process. Chromium and nickel simultaneous removal was best achieved for conditions of 100 mg l-1 initial concentration, pH 5 and a current of 0.8 A.</p>

scholarly journals Removal Efficiency of Acid Red 18 Dye from Aqueous Solution Using Different Aluminium-Based Electrode Materials by Electrocoagulation Process

2020 ◽  
Vol 20 (3) ◽  
pp. 536
Author(s):  
Nurulhuda Amri ◽  
Ahmad Zuhairi Abdullah ◽  
Suzylawati Ismail
Keyword(s):  
Reaction Time ◽  
Removal Efficiency ◽  
Industrial Wastewater ◽  
Electrode Materials ◽  
Cost Effective ◽  
Aluminium Electrode ◽  
Electrocoagulation Process ◽  
Commercial Aluminium ◽  
A Current ◽  
Better Than

This work compares commercial aluminium electrode for use in the treatment of wastewater by electrocoagulation process against waste aluminium cans electrode. The applicability of the waste aluminium cans electrode was tested for decolorization of Acid Red 18 dye as a model pollutant. The batch electrocoagulation process using both types of electrode was conducted at a current density of 25 mA/cm2, a pH of 3, an initial concentration of 100 mg/L and 25 min of reaction time. The elemental composition and surface morphology of both electrode materials and the sludge produced were analyzed using SEM-EDX to establish the correlation between the properties and characteristics of both electrode materials with their dye removal performance. The results demonstrated that waste aluminium cans performed better than commercial aluminium electrode with a removal efficiency of 100% in 25 min of reaction time. This was due to the higher Al dissolution of waste aluminium cans electrode that contributed to the larger amount of Al3+ released into the solution to consequently form more flocs to remove the dye molecules. In conclusion, the proposed waste aluminium electrode was considered as efficient and cost-effective and had the potential to replace the conventional ones in treating colored industrial wastewater using electrocoagulation process.

scholarly journals A Study on Lithium Hydroxide Recovery Using Bipolar Membrane Electrodialysis

2021 ◽  
Vol 59 (4) ◽  
pp. 223-232
Author(s):  
Yeonchul Cho ◽  
Kihun Kim ◽  
Jaewoo Ahn ◽  
Jaeheon Lee
Keyword(s):  
Sulfuric Acid ◽  
Energy Consumption ◽  
Applied Voltage ◽  
Processing Time ◽  
Volume Ratio ◽  
Lithium Hydroxide ◽  
Raw Material ◽  
Process Time ◽  
Lithium Sulfate ◽  
Material Solution

Bipolar electrodialysis was used in a process of desalting a lithium sulfate solution, converting it to lithium hydroxide and sulfuric acid, and concentrating and recovering them. The effects of the experimental variables such as applied voltage, the concentration of electrode solution, the concentration of raw material solution, volume ratio, and impurity were confirmed. The optimum conditions were investigated by comparing the conversion(%) of lithium hydroxide and sulfuric acid, the process time, and energy consumption. As the applied voltage was increased, the energy consumption tended to increase, but the processing time decreased significantly. As the concentration of lithium sulfate in the raw material solution increased, the conversion(%) of lithium hydroxide decreased. As the concentration of lithium sulfate increased, the energy consumption did not increase linearly, and energy consumption increased significantly. When a raw material solution of 0.5 M Li<sub>2</sub>SO<sub>4</sub> or more is used in the bipolar electrodialysis process, an applied voltage of 25 V is preferable. As the applied voltage increased at a constant process time, the conversion(%) of LiOH and H<sub>2</sub>SO<sub>4</sub> increased. Regarding the effect of the electrode solution concentration, when a 5.0 wt% electrode solution was used rather than a 3.0 wt% electrode solution, energy consumption decreased by more than 10%. When the volume of the raw material solution was increased, the processing time required for desalting increased. By using a low concentration raw material solution, it was confirmed that it was simultaneously possible to recover and concentrate lithium hydroxide and sulfuric acid through volume ratio control. When the raw material solution contained Na as an impurity, it was converted to NaOH with a surface LiOH, and it was not possible to separate the lithium and sodium.

scholarly journals Elimination of chemical oxygen demand from domestic residual water by electrocoagulation with aluminum and iron electrodes

2018 ◽  
Vol 13 (5) ◽  
pp. 1
Author(s):  
Edwar Alejandro Aguilar Ascón
Keyword(s):  
Chemical Oxygen Demand ◽  
Treatment Time ◽  
Treatment Plant ◽  
Oxygen Demand ◽  
Current Intensity ◽  
Residual Water ◽  
Response Variable ◽  
Iron Electrodes ◽  
Electrocoagulation Process ◽  
A Current

This research determined the efficiency of removal of chemical oxygen demand (COD) by an electrocoagulation process. An electrocoagulation reactor with aluminum and iron electrodes was used to treat water from the treatment plant of the Research Center for Wastewater Treatment and Hazardous Waste. The COD removal percentage was a response variable for the experimental factorial design. The factors influencing the process were current intensity, treatment time, and pH. The best results in the percentage of removal of the COD were very similar to that obtained at a pH of 8.2 and 7, with values of 83% and 84%, respectively, with a current intensity of 7 A and a treatment time of 15 min. However, at 5 A and 10 min, values that exceed 80% removal were obtained. Statistical analysis indicates that only current intensity and time were significant for the response variable. Electrocoagulation is a viable process for the treatment of this type of effluent, in addition to being more versatile compared with biological processes.

A new tool for rapid development of electron microscopy negatives and micrographs: Initial impressions of the MOHR/PRO-8 processor

1992 ◽  
Vol 50 (2) ◽  
pp. 972-973
Author(s):  
James C. Long
Keyword(s):  
Electron Microscopy ◽  
Processing Time ◽  
Rapid Development ◽  
Processing Times ◽  
Initial Impressions ◽  
Transport Method

Over the years, many techniques and products have been developed to reduce the amount of time spent in a darkroom processing electron microscopy negatives and micrographs. One of the latest tools, effective in this effort, is the Mohr/Pro-8 film and rc paper processor.At the time of writing, a unit has been recently installed in the photographic facilities of the Electron Microscopy Center at Texas A&M University. It is being evaluated for use with TEM sheet film, SEM sheet film, 35mm roll film (B&W), and rc paper.Originally designed for use in the phototypesetting industry, this processor has only recently been introduced to the field of electron microscopy.The unit is a tabletop model, approximately 1.5 × 1.5 × 2.0 ft, and uses a roller transport method of processing. It has an adjustable processing time of 2 to 6.5 minutes, dry-to-dry. The installed unit has an extended processing switch, enabling processing times of 8 to 14 minutes to be selected.

scholarly journals Substrate adhesion evolves non-monotonically with processing time in millimeter-scale aligned carbon nanotube arrays

Nanoscale ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 261-271
Author(s):  
Ashley L. Kaiser ◽  
Dale L. Lidston ◽  
Sophie C. Peterson ◽  
Luiz H. Acauan ◽  
Stephen A. Steiner ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Adhesion Strength ◽  
Processing Time ◽  
Effective Modulus ◽  
Work Of Adhesion ◽  
Process Time ◽  
Nanotube Arrays ◽  
Substrate Adhesion ◽  
Carbon Nanotube Arrays

Aligned carbon nanotube (CNT) array adhesion strength evolves with CNT process time, decreasing and then increasing during growth and annealing, as captured by models relating CNT diameter, array effective modulus, and CNT–substrate work of adhesion.

Unrelated Parallel-Machine Scheduling with Controllable Processing Times and Impact of Deteriorating Maintenance Activities under Consideration

2016 ◽  
Vol 33 (01) ◽  
pp. 1650001 ◽  
Author(s):  
Chun-Lai Liu ◽  
Jian-Jun Wang
Keyword(s):  
Processing Time ◽  
Machine Scheduling ◽  
Parallel Machine Scheduling ◽  
Parallel Machine ◽  
Controllable Processing Times ◽  
Maintenance Activity ◽  
Processing Times ◽  
Unrelated Parallel Machine Scheduling ◽  
Deteriorating Maintenance ◽  
Maintenance Activities

In this paper, we study the problem of unrelated parallel machine scheduling with controllable processing times and deteriorating maintenance activity. The jobs are nonresumable. The processing time of each job is a linear function of the amount of a continuously divisible resource allocated to the job. During the planning horizon, there is at most one maintenance activity scheduled on each machine. Additionally, if the starting time of maintenance activity is delayed, the length of the maintenance activity required to perform will increase. Considering the total completion times of all jobs, the impact of maintenance activity in the form of the variation in machine load and the amounts of compression, we need to determine the job sequence on each machine, the location of maintenance activities and processing time compression of each job simultaneously. Accordingly, a polynomial time solution to the problem is provided.

scholarly journals Application of Electrocoagulation Process for Dairy Wastewater Treatment

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Edris Bazrafshan ◽  
Hossein Moein ◽  
Ferdos Kord Mostafapour ◽  
Shima Nakhaie
Keyword(s):  
Reaction Time ◽  
Applied Voltage ◽  
Oxygen Demand ◽  
Dairy Wastewater ◽  
Operating Parameters ◽  
Pollution Load ◽  
Reliable Technique ◽  
Electrocoagulation Process ◽  
Aluminum Electrodes ◽  
Industry Wastewater

Dairy industry wastewater is characterized by high biochemical oxygen demand (BOD5), chemical oxygen demand (COD), and other pollution load. The purpose of this study was to investigate the effects of the operating parameters such as applied voltage, number of electrodes, and reaction time on a real dairy wastewater in the electrocoagulation process. For this purpose, aluminum electrodes were used in the presence of potassium chloride as electrolytes. It has been shown that the removal efficiency of COD, BOD5, and TSS increased with increasing the applied voltage and the reaction time. The results indicate that electrocoagulation is efficient and able to achieve 98.84% COD removal, 97.95% BOD5removal, 97.75% TSS removal, and >99.9% bacterial indicators at 60 V during 60 min. The experiments demonstrated the effectiveness of electrocoagulation techniques for the treatment of dairy wastewaters. Finally, the results demonstrated the technical feasibility of electrocoagulation process using aluminum electrodes as a reliable technique for removal of pollutants from dairy wastewaters.

Room Temperature Band-Edge Luminescence from Silicon Grains Prepared by the Recrystallization of Mesoporous Silicon

1996 ◽  
Vol 452 ◽  
Author(s):  
Karen L. Moore ◽  
Leonid Tsybeskov ◽  
Philippe M. Fauchet ◽  
Dennis G. Hall
Keyword(s):  
Room Temperature ◽  
Silicon Oxide ◽  
Crystalline Silicon ◽  
Band Edge ◽  
Applied Bias ◽  
Mesoporous Silicon ◽  
Room Temperature Photoluminescence ◽  
Band Edge Luminescence ◽  
A Current ◽  
Better Than

AbstractRoom-temperature photoluminescence (PL) peaking at 1.1 eV has been found in electrochemically etched mesoporous silicon annealed at 950°C. Low-temperature PL spectra clearly show a fine structure related to phonon-assisted transitions in pure crystalline silicon (c-Si) and the absence of defect-related (e.g.P-line) and impurity-related (e.g.oxygen, boron) transitions. The maximum PL external quantum efficiency (EQE) is found to be better than 0.1% with a weak temperature dependence in the region from 12K to 400K. The PL intensity is a linear function of excitation intensity up to 100 W/cm2. The PL can be suppressed by an external electric field ≥ 105 V/cm. Room temperature electroluminescence (EL) related to the c-Si band-edge is also demonstrated under an applied bias ≤ 1.2 V and with a current density ≈ 20 mA/cm2. A model is proposed in which the radiative recombination originates from recrystallized Si grains within a non-stoichiometric Si-rich silicon oxide (SRSO) matrix.

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