scholarly journals An Enhanced Electrocoagulation Process for the Removal of Fe and Mn from Municipal Wastewater Using Dielectrophoresis (DEP)

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 485
Author(s):  
Abdulkarim Almukdad ◽  
Alaa H. Hawari ◽  
MhdAmmar Hafiz

In this study the removal of Fe and Mn from primary treated municipal wastewater using a new electrode configuration in electrocoagulation was evaluated. The used electrode configuration induced a dielectrophoretic (DEP) force in the electrocoagulation process. The impact of the electrolysis time, electrodes spacing and applied current on the removal of Fe and Mn was evaluated. The maximum removal percentages of Fe and Mn were obtained using an electrolysis time of 60 min, an electrode spacing of 0.5 cm and an applied current of 800 mA. Under these operating conditions and using the new electrodes configuration, the Fe and Mn removals were 96.8% and 66%, respectively. The main advantage of using the DEP-induced electrode configuration was the minimal consumption of the electrodes. The new electrode configuration showed 42% less aluminum content in the reactor compared to the aluminum electrodes with no DEP effect. The energy consumption at the selected operation conditions was 4.88 kWh/m3. The experimental results were comparable with the simulation results achieved by the COMSOL software.

2017 ◽  
Vol 5 (7) ◽  
pp. 348-353
Author(s):  
Krishna M. K ◽  
Manjunath H.N ◽  
Ayesha Siddiqa

The various electrodes such as iron, aluminium, stainless steel and graphite are used in this study. Main objectives of the present paper is to evaluate the removal of COD, pH, TDS and oil and grease from the automobile wastewater by Electro coagulation using iron as Monopolar configuration at different voltages and electrolysis time. To study the effect of inter electrode spacing and effect of different initial pH for the removal of selected parameter at constant voltage for the iron electrode. The removal efficiency decreases with increase in electrode spacing as 71.2% of COD, 96.5% of TDS and 88.76% of oil and grease removal was achieved with iron electrode.


Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1213
Author(s):  
Michael Betz ◽  
Marco Gleiss ◽  
Hermann Nirschl

This paper presents a study of the use of flow baffles inside a centrifugal air classifier. An air classifier belongs to the most widely used classification devices in mills in the mineral industry, which is why there is a great interest in optimizing the process flow and pressure loss. Using Computational Fluid Dynamics (CFD), the flow profile in a classifier without and with flow baffles is systematically compared. In the simulations, turbulence effects are modeled with the realizable k–ε model, and the Multiple Reference Frame approach (MRF) is used to represent the rotation of the classifier wheel. The discrete phase model is used to predict the collection efficiency. The effects on the pressure loss and the classification efficiency of the classifier are considered for two operating conditions. In addition, a comparison with experimental data is performed. Firstly, the simulations and experiments show good agreement. Furthermore, the investigations show that the use of flow baffles is suitable for optimizing the flow behavior in the classifier, especially in reducing the pressure loss and therefore energy costs. Moreover, the flow baffles have an impact on the classification performance. The impact depends on the operation conditions, especially the classifier speed. At low classifier speeds, the classifier without flow baffles separates more efficiently; as the speed increases, the classification performance of the classifier with flow baffles improves.


2014 ◽  
Vol 79 (5) ◽  
pp. 613-626 ◽  
Author(s):  
K. Thirugnanasambandham ◽  
V. Sivakumar ◽  
Maran Prakash

The main objective of the present study was to investigate the efficiency of electrocoagulation process as a post-treatment to treat biologically pretreated bagasse effluent using iron electrodes. The removal of chemical oxygen demand (COD) and total suspended solids (TSS) were studied under different operating conditions such as amount of dilution, initial pH, applied current and electrolyte dose by using response surface methodology (RSM) coupled with four-factor three-level Box-Behnken experimental design (BBD). The experimental results were analyzed by Pareto analysis of variance (ANOVA) and second order polynomial mathematical models were developed with high correlation of efficiency (R2) for COD, TSS removal and electrical energy consumption (EEC). The individual and combined effect of variables on responses was studied using three dimensional response surface plots. Under the optimum operating conditions, such as amount of dilution at 30 %, initial pH of 6.5, applied current of 8 mA cm-2 and electrolyte dose of 740 mg l-1 shows the higher removal efficiency of COD (98 %) and TSS (93 %) with EEC of 2.40 Wh, which were confirmed by validation experiments.


2013 ◽  
Vol 820 ◽  
pp. 25-29
Author(s):  
Jing Bo Wu ◽  
Mao Quan Li ◽  
Shu Hai Zhang ◽  
Yun Long Mei ◽  
Ze Tao Gao

PTFE/Al reactive material was prepared via a hot pressed sintering process and comparative experiments were conveyed considering heating rate, sintering temperature and heat preservation time. The internal microstructure of the material was investigated using metallurgical microscope and stereomicroscope. From the investigation the influence of process parameters of hot pressed sintering on the properties of the material were deduced, and the analysis was verified by testing the impact initiation property with drop hammer method. The density of the material was measured according to the Archimedean principle. and the results showed that the best operating conditions of these three factors are 80°C/h, 365°C, and 0.5h, This new method has a higher effectively (short process time) and need lower operation conditions (low sintering temperature and pressure) comparing with the traditional cold sintering process.


2021 ◽  
Vol 896 (1) ◽  
pp. 012049
Author(s):  
W Oktiawan ◽  
B P Samadikun ◽  
Junaidi ◽  
I G N Bramahesa ◽  
T A Taqiyya ◽  
...  

Abstract Almost all human life requires water, one of which is washing clothes. However, city people tend to use laundry services. It is necessary to treat laundry wastewater because it contains parameters that can cause environmental pollution. A promising technique has been found to treat urban wastewater, especially laundry wastewater. An electrochemical method for water treatment is known as electrocoagulation, in which a solution of an active coagulant in the form of metal ions (aluminum or iron) is introduced into a solution. In electrocoagulation, the processes of adsorption, coagulation, precipitation, and flotation taking place. This research was conducted to determine the impact of current on electrocoagulation using Al-Al, Fe-Fe, Al-Fe, Fe-Al electrodes in reducing surfactant levels in laundry wastewater with variations in the voltage used were 20 V, 30 V, 40 V, and 60 V. The results showed that the electrocoagulation process could remove surfactants in laundry wastewater. A voltage of 30 volts with Al-Al electrode configuration was used for 30 minutes to obtain optimum conditions so that it will get a surfactant effluent concentration of 5.77 mg/L with a removal efficiency of 72.89%.


2021 ◽  
Vol 24 (6) ◽  
pp. 1199-1208
Author(s):  
L. A. Sladkova ◽  
V. V. Krylov ◽  
F. A. Kuznetsov

The purpose of the paper is to reproduce a standard wind flow (laminar, turbulent, pulsating modes) to study the impact on crane structures, with the aim to obtain the load values of crane elements most closely approximate to real conditions. When creating an installation, which is related to the field of experimental aerodynamics, the "principle of simulating the main factors determined by the operating conditions of the research object" is adopted to ensure the r eproducibility of test results to the maximum extent. To confirm the performance efficiency of the proposed installation device, its computer model is developed using the CAD software SolidWorks. The computer model parameters are in full geometric agreement with the dimensions of the developed real installation. The use of the installation makes it possible to study the dynamic effect of the wind on the stability of crane structures in various operation modes (change in wind speed, in the mode of load operation, in operation conditions at the wall, etc.). The proposed installation allows to simulate the loads on crane equipment with the possibility of characteristics expanding, for example, its carrying capacity. The generated computer model of the installation makes it possible to reveal the physical picture of wind flow distribution at the installation outlet. The results of wind flow simulation on the proposed installation are confirmed on a computer model with a high degree of convergence of results at wind speeds of 2.5 m/s and lower The installation proposed by the authors will allow to simulate: the value of the real average statistical wind load of various intensity; pulsating component of the wind load; vortex excitation; increase of the available aerodynamic research capability for a real crane structure. The developed installation is a calibration device for external impacts of the wind force on the crane structure.


2020 ◽  
Vol 10 (1) ◽  
pp. 86-95
Author(s):  
Shubhrasekhar Chakraborty ◽  
Pratap Kumar Mohanty ◽  
Jawed Iqbal ◽  
R. Naresh Kumar

Abstract A combined process of sequencing batch reactor (SBR) and electrocoagulation for co-treatment of landfill leachate and municipal wastewater was assessed. SBR was used in the first instance for co-treatment of 20% (v/v) landfill leachate and municipal wastewater mixture. Effluent from SBR was subjected to electrocoagulation for post-treatment, with aluminum as sacrificial anode and stainless steel as cathode. Direct current at a density of 257 A/m2 was applied during the electrocoagulation process. In electrocoagulation, spacing between the two electrodes was varied at 5 and 7 cm to assess its influence on treatment efficiency. SBR was effective to remove 65% chemical oxygen demand (COD), 77% total suspended solids (TSS), 89% ammonia, 80% nitrate, 64% phosphate and post-treatment by electrocoagulation resulted in an overall 98% COD, 98% TSS and 99% ammonia, nitrate and phosphate reduction efficiency with 5 cm of electrode spacing. Respectively, final COD, ammonia and TSS was 37, 1 and 98 mg/L after 150 min of electrocoagulation which met the Indian standards for the discharge of treated wastewater. The results highlight that SBR followed by electrocoagulation as post-treatment can be an effective option for the treatment of landfill leachate and municipal wastewater mixture.


2005 ◽  
Vol 33 (3) ◽  
pp. 156-178 ◽  
Author(s):  
T. J. LaClair ◽  
C. Zarak

Abstract Operating temperature is critical to the endurance life of a tire. Fundamental differences between operations of a tire on a flat surface, as experienced in normal highway use, and on a cylindrical test drum may result in a substantially higher tire temperature in the latter case. Nonetheless, cylindrical road wheels are widely used in the industry for tire endurance testing. This paper discusses the important effects of surface curvature on truck tire endurance testing and highlights the impact that curvature has on tire operating temperature. Temperature measurements made during testing on flat and curved surfaces under a range of load, pressure and speed conditions are presented. New tires and re-treaded tires of the same casing construction were evaluated to determine the effect that the tread rubber and pattern have on operating temperatures on the flat and curved test surfaces. The results of this study are used to suggest conditions on a road wheel that provide highway-equivalent operating conditions for truck tire endurance testing.


2019 ◽  
pp. 43-48
Author(s):  
Ben Nengjun ◽  
Zhou Pengfei ◽  
Oleksandr Labartkava ◽  
Mykhailo Samokhin

This work involves an analysis of high-chromium high-temperature deformable wieldable nickel alloys for use in GTE repair assemblies. It is shown that the alloys EP868 (VZh98) and Haynes 230 can be used in welded assemblies with an operating temperature of 800-1100 °C. The alloys Nimonic 81, Nimonic 91, IN 935, IN 939, and Nicrotan 2100 GT also have a high potential for use in welded assemblies. They are characterized by a combination of good weldability, high-temperature strength, and resistance to scaling. There have been conducted studies on high-temperature salt corrosion of model nickel alloys. They allowed establishing the patterns of the impact of base metal alloying with chromium, aluminum, titanium, cobalt, tungsten, molybdenum, niobium, tantalum and rare earth metals on the critical temperature of the start of salt corrosion Tcor and the alloy mass loss. It has been established that alloys with a moderate concentration (13-16%) of chromium can possess satisfactory hightemperature corrosion resistance (HTC resistance) under the operating conditions of ship GTE. The HTC resistance of CrAl-Ti alloys improves upon reaching the ratio Ti/Al ˃ 1. Meanwhile, the ratio Ti/Al ˂ 1 promotes the formation of corrosion products with low protective properties. The positive effect of tantalum on the HTC resistance of alloys is manifested at higher test temperatures than that of titanium, and the total content of molybdenum and tungsten in alloys is limited by the condition 8Mo2 – 2W2 = 89. The presence of refractory elements stabilizes the strengthening phase and prevents formation of the ɳ-phase. However, their excess promotes formation of the embrittling topologically close packed (TCP) phases and boundary carbides of an unfavorable morphology. Based on the studies of the HTC resistance, there has been identified a class of model high-temperature corrosionresistant nickel alloys with a moderate or high chromium content (30%), Ti/Al ˃ 1, and a balanced content of refractory and rare-earth elements.


2014 ◽  
pp. 298-301 ◽  
Author(s):  
Arnaud Petit

Bois-Rouge factory, an 8000 t/d cane Reunionese sugarcane mill, has fully equipped its filtration station with vacuum belt press filters since 2010, the first one being installed in 2009. The present study deals with this 3-year experience and discusses operating conditions, electricity consumption, performance and optimisation. The comparison with the more classical rotary drum vacuum filter station of Le Gol sugar mill highlights advantages of vacuum belt press filters: high filtration efficiency, low filter cake mass and sucrose content, low total solids content in filtrate and low power consumption. However, this technology needs a mud conditioning step and requires a large amount of water to improve mud quality, mixing of flocculant and washing of filter belts. The impact on the energy balance of the sugar mill is significant. At Bois-Rouge mill, studies are underway to reduce the water consumption by recycling low d.s. filtrate and by dry cleaning the filter belts.


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