Influence factors and current response of carbon cloth bipolar plate electro-enhanced bioreactor (CBEEB) for nitrogen removal

2021 ◽  
Author(s):  
Wu Kejia ◽  
Zhu Hongguang ◽  
Wang Bowen
2011 ◽  
Vol 189-193 ◽  
pp. 2613-2620 ◽  
Author(s):  
Hai Ming Huang ◽  
Qian Wu Song ◽  
Chun Lian Xu

Struvite (MgNH4PO4∙6H2O) is an insoluble double salt. It can precipitate in places such as pipes, aerators and pumps, which could lead to substantial problems influencing the normal operation of wastewater treatment equipments. At present, removal of ammonium nitrogen from various wastewaters by the formation of struvite has been widely investigated. This paper reviewed the research and application efforts concerning the treatment of ammonium nitrogen by struvite precipitation, which were obtained at home and abroad in recent years. The mechanism and influence factors of struvite precipitation for ammonium nitrogen removal were discussed. Additionally, the problems that still should be resolved and the research directions in future were pointed out.


Author(s):  
Aris Mukimin ◽  
Nur Zen ◽  
Hanny Vistanty ◽  
Purwanto Agus

Microbial fuel cell (MFC) is a new proposed technology reported to generate renewable energy while simultaneously treating wastewater. Membraneless microbial fuel cell (ML-MFC) system was developed to eliminate the requirement of membrane which is expensive and prone to clogging while enhancing electricity generation and wastewater treatment efficiency. For this purpose, a reactor was designed in two chambers and connected via three pipes (1 cm in diameter) to enhance fluid diffusion. Influent flowrate was maintained by adjusting peristaltic pump at the base of anaerobic chamber. Carbon cloth (235 cm2) was used as anode and paired with gas diffusion layer (GDL) carbon-Pt as cathode. Anaerobic sludge was filtered and used as starter feed for the anaerobic chamber. The experiment was carried out by feeding synthetic wastewater to anaerobic chamber; while current response and potential were recorded. Performance of reactor was evaluated in terms of chemical oxygen demand (COD). Electroactive microbe was inoculated from anaerobic sludge and showed current response (0.55-0.65 mA) at 0,35 V, range of diameter 1.5-2 µm. The result of microscopics can showed three different species. The microbial performance was increased by adding ferric oxide 1 mM addition as acceptor electron. The reactor was able to generate current, voltage, and electricity power of 0.36 mA, 110 mV, and 40 mWatt (1.5 Watt/m2), respectively, while reaching COD removal and maximum coulomb efficiency (EC) of 16% and 10.18%, respectively.


Author(s):  
R. Roshandel

Catalyst layers are one of the most important parts of the PEM fuel cells and the cell performance is highly related to its structure. Catalyst layers are generally made by uniform distribution of catalyst on carbon cloth or carbon papers to form electrodes. In this paper, the idea of using non-uniform catalyst layer instead of common uniform catalyst layers is presented and simulated by a two-dimensional steady-state computational model. The model accounts for species transport, electrochemical kinetics, charge transport and current density distribution. A fuel cell test stand is designed and built to facilitate experimental validation of the model. Modeling results show that electrical current in catalyst layer is non-uniform, influenced by the channel-land patterns in bipolar plate geometry. Our simulations results also suggest that some non-uniform catalyst distribution patterns regarding to bipolar plate configuration will improve the performance of the whole catalyst layer by increasing catalyst utilization factor. Therefore, it is necessary to design non-uniform catalyst layers regarding to specific procedure. Plasma sputtering method is used to fabricate non-uniform catalyst layers. In this method, the platinum is deposited on the carbon cloth in the plasma-processing chamber. Indeed, an experimental procedure is presented to facilitate the fabrication of non-uniform catalyst layers by plasma sputtering.


2012 ◽  
Vol 549 ◽  
pp. 92-95
Author(s):  
Fei Liu ◽  
Tao Hu ◽  
Shi Ying Ren ◽  
Ying Ying Shi

The removal of ammonia-nitrogen (NH4+–N) in water by activated attapulgite was investigated. The study focuses on the effect of different activated attapulgite. The influence factors include microwave power, heating time and pH value in solution. The results show that heating 4 minutes, microwave power of 89 watts, and pH value of 9 are the best conditions to remove NH4+-N in the wastewater and the removal efficiency can above 80%. The attapulgite activated by microwave and alkali can remove NH4+-N in breeding waste effectively and the removal efficiency can reach 84.15%.


2014 ◽  
Vol 955-959 ◽  
pp. 2581-2584
Author(s):  
Ji Ku Zhang ◽  
Jun Lin Wang ◽  
Xiao Tong Zhang

For accurate test on the influence factors of nitrogen removal in constructed wetland technology, experiment to simulate the integrated vertical-flow constructed wetland processing of central drainage water in Shenyang Architecture University, mainly analysis the efficiency of nitrogen removal. The results show that we ultimately determine the influencing factors on the removal rate of nitrogen effect model by analyzing the data through multiple linear regression method. It is proved that the prediction results were exact, and can be used to guide the eutrophic landscape water body treatment and pollution control field Construction of constructed wetland technology in China.


Author(s):  
Terry B. Caston ◽  
Kanthi L. Bhamidipati ◽  
Haley Carney ◽  
Tequila A. L. Harris

The goal of this study is to design a gas diffusion layer (GDL) for a polymer electrolyte membrane (PEM) fuel cell with a graduated permeability, and therefore a graduated resistance to flow throughout the GDL. It has been shown that using conventional materials the GDL exhibits a higher resistance in the through-plane direction due to the orientation of the small carbon fibers that make up the carbon paper or carbon cloth. In this study, a GDL is designed for an unconventional PEM fuel cell stack, where the reactant gases are supplied through the side of the GDL rather than through flow field channels, which are machined into a bipolar plate. The effects of changing in-plane permeability, through-plane permeability, and thickness of the GDL on the expected current density distribution at the catalyst layer are studied. Three different thicknesses are investigated, and it is found that as GDL thickness increases, more uniform reactant distribution over the face of the GDL is obtained. Results also show that it is necessary to design a GDL with a much higher in-plane resistance than through-plane resistance for the unconventional PEM stack studied.


2007 ◽  
Vol 26-28 ◽  
pp. 853-856 ◽  
Author(s):  
Hong Ki Lee ◽  
Soo Heun Chae ◽  
Joong Pyo Shim ◽  
Sung Won Yang

The decrease of material cost for manufacturing fuel cell stack is strongly required for overcoming commercial restriction. The epoxy based graphite bipolar plate (BP) for polymer electrolyte membrane fuel cells (PEMFC) has been prepared and electrical, mechanical and thermal properties were compared. The density of graphite composite bipolar plate showed from 1.67 to 2.54 as graphite content is increased from 60 to 80w/o and decreased as expanded graphite was added. The contact resistance between epoxy/graphite bipolar plate and gas diffusion layer (GDL) had lower value using carbon cloth than carbon paper for GDL. The conformation of thermal stability, improvement of mechanical and electrical properties was accomplished by addition of expanded graphite powder.


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