Dark Current and Magnetic Field in Liquid

The dark electric current arising from the contact of aluminum with clean water decreases with an increase in the induction of the external magnetic field. Changing the distance between the source of the magnetic field and the aluminum electrodes makes it possible to determine the region of formation of the dark current. It turns out that this occurs in the area of liquid-metal contact where the curvature of the electrodes is maximal.

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

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.

Influence of the Condition of the Exposed Electrode Edge in the SDBD on the Discharge Operation Mode in Argon

The paper is devoted to the phenomenological study of the operating modes of a surface barrier discharge in argon in the case of treated by the discharge and new aluminum and copper electrodes. It is shown that without preliminary treating of the edges of the electrodes in the case of copper and aluminum electrodes, the discharge has a different spatial structure determined by the self-organization of the DBD. After erosion cleaning of the electrode edges, the identical operating modes are established. Such effects confirm the former assumption that the key factor determining the mode of the discharge operation for various electrode materials is the surface charge built on the oxides deposited on the edge. The different dynamics of oxides in the case of copper and aluminum electrodes is determined by the resistance of the oxides of these metals to sputtering, which is indirectly confirmed by the estimation of the binding energy for these materials.

Investigation of the aluminum electrodes erosion of a plasma gun during the operation of a high-current vacuum arc discharge

The aim of this work was to obtain magnitude quantitative estimates of the “closed-type” plasma gun aluminum electrodes erosion that occurs during the course of a high-current vacuum arc discharge. The experimental setup consisted of two current generators. The first generator capable of generating a current with an amplitude of up to 450 kA and a rise time of 500 ns was used as a current source for a plasma gun. The second one was used as an X-ray radiograph to visualize the object under study in the soft X-ray range (hv ≈ 0.5–3 keV). Quantitative distributions of the plasma linear mass are obtained both along the radius and along the length of the jet at different times. It was shown that the erosion properties of the electrode material are related to the current characteristics of the arc discharge current.

The Use of Electrocoagulation to Remove Fluoride, Nitrates and Phosphorous from Water

In recent times, the concentrations of fluoride, nitrates and phosphates in the water have increased as a result of a decrease in the quantities of water and an increase in industrial waste dumped into the rivers. In the current study, a method of electrocoagulation was depended on to treat water contaminated with fluoride, nitrates, and phosphates, using aluminum electrodes as anode and cathode electrodes. According to the obtained results, it can be noticed that the best fluoride, nitrates, and phosphates removal were 99%, 99%, 100%, respectively. It was obtained with a Hydraulic retention time HRT = 3 hours, an applied voltage = 40 volts, a gap between the used electrodes=2 cm, the anode’s active area= 792 cm2, and the flow angle= zero. By using an initial concentration (5 mg F/l, with pH= 4) for fluoride, (75 mg NO3/l, with pH= 6) for nitrates, and (0.5 mg PO4 / l, with pH=9) for phosphates.

Pengaruh Beda Potensial dan Waktu Kontak terhadap Penurunan Kadar COD dan TSS pada Limbah Batik menggunakan Metode Elektrokagulasi

Batik is one of Indonesia's original cultural heritage that must be preserved. However, the resulting liquid waste has a negative impact on the environment because it contains high levels of phosphate, surfactant, TSS, TDS, turbidity, BOD5 and COD contaminants. An effective method for dealing with batik waste is electrocoagulation, which is coagulation in the presence of an electric current using electrodes. This study treats batik waste by electrocoagulation using aluminum electrodes, which are operated at a current of 5 Ampere, electrode distance is 2 cm, electrode thickness is 0.1 cm, electrode cross-sectional area is 7x10 cm with a waste volume of 500 mL. The effect of potential difference treatment (3 volts, 4.5 volts, 7.5 volts, 9 volts, and 12 volts) and contact time (15 minutes, 20 minutes, 25 minutes, 30 minutes, and 35 minutes) on changes in COD and TSS levels were studied. Optimal conditions were obtained at a potential difference of 12 volts for 35 minutes with a COD reduction efficiency of 84.84% and 91% for TSS.