Upgrade of three municipal wastewater treatment lagoons using a high surface area media

Volumetric diameters Dv and specific surface area SpS of sludge particles formed during chemical coagulation and electrocoagulation of sewage were determined. The obtained aggregate-flocs differed substantially in both Dv and SpS values. The differences in Dv and SpS values of the analyzed particles were interpreted based on theoretical models for expanding aggregates. The most uniform particles were formed under exposure to: (a) optimal and maximal doses of PIX, (b) optimal doses of PAX, (c) maximal doses of the Al electro-coagulant. The lowest PIX dose produced the least uniform particles. Sludge aggregates-particles produced under exposure to minimal doses of PIX and the Al electro-coagulant were characterized by the lowest SpS values. Sludge particles coagulated by PAX and the particles formed at higher doses of PIX and the Al electro-coagulant had higher SpS values. The particles formed at all doses of the applied coagulants and electro-coagulants were generally classified into two size ranges: the main range and the secondary range. Most particles belonged to the main size range. An increase in the percentage of colloidal hydroxide particles in sewage sludge increased SpS.

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Design and Manufacturing of High Surface Area 3D-Printed Media for Moving Bed Bioreactors for Wastewater Treatment

Journal of Contemporary Water Research & Education ◽

10.1111/j.1936-704x.2017.03246.x ◽

2017 ◽

Vol 160 (1) ◽

pp. 144-156 ◽

Cited By ~ 16

Author(s):

Olivia Elliott ◽

Stephanie Gray ◽

Michael McClay ◽

Bakr Nassief ◽

Ann Nunnelley ◽

...

Keyword(s):

Wastewater Treatment ◽

Surface Area ◽

High Surface ◽

High Surface Area ◽

Moving Bed ◽

Printed Media ◽

Design And Manufacturing ◽

3D Printed

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Use of Ash from Sewage Sludge in the Preparation of Desulfurant Sorbents

International Journal of Chemical Reactor Engineering ◽

10.2202/1542-6580.2102 ◽

2010 ◽

Vol 8 (1) ◽

Author(s):

Josefa Fernández Ferreras ◽

Hipolito García Posadas ◽

Jose Luis Rico Gutierrez ◽

Josefina Renedo Omaechevarría

Keyword(s):

Wastewater Treatment ◽

Sewage Sludge ◽

Specific Surface ◽

Surface Area ◽

Specific Surface Area ◽

Municipal Wastewater ◽

Fixed Bed Reactor ◽

Municipal Wastewater Treatment ◽

Bet Specific Surface Area ◽

Two Temperatures

This work aims to develop new uses for sewage sludge, which is a byproduct of municipal wastewater treatment plants, by examining the calcination of this waste, the characterization of ashes is obtained, and its use to prepare desulfurant sorbents. Samples of sewage sludge were obtained from a local municipal wastewater treatment plant. This plant applies a pre-treatment followed by a biological treatment, where anaerobic digestion and centrifugation reduces the sludge. Three samples were characterized (in humidity, volatile and fixed solids content), dried, and ignited at two temperatures, 550 and 750°C. The composition of the ash obtained at both ignition temperatures was studied by x-ray fluorescent spectroscopy and the BET specific surface area of the two ashes and of the prepared sorbents was measured. Ash composition was similar for the two temperatures tested, where the components were Si, Ca, Al, Fe, P, S, Mg, K, Cl, Zn and Ti. BET specific surface area values indicate that the lower temperature of calcination produces ash with the highest SSA values (18 m2/g against near 10 m2/g). Preparation of desulfurant sorbents was carried out by mixing the ash with CaO or Ca(OH)2 at room temperature and different experimental conditions. The BET SSA of the prepared desulfurant sorbents showed higher values for the sorbents prepared with the ashes obtained at the lowest temperature. The behaviour of the ash and the prepared sorbents was tested in a fixed bed reactor at 58°C with a flue gas containing 5000 ppm of SO2 with a relative humidity of 55%. Results in the desulfurization process show that the calcium from the sludge seems more efficient than the calcium added as CaO or Ca(OH)2 to prepare the sorbents.

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Analysis of very-high surface area 3D-printed media in a moving bed biofilm reactor for wastewater treatment

PLoS ONE ◽

10.1371/journal.pone.0238386 ◽

2020 ◽

Vol 15 (8) ◽

pp. e0238386

Author(s):

Gabriel Proano-Pena ◽

Andres L. Carrano ◽

David M. Blersch

Keyword(s):

Wastewater Treatment ◽

Surface Area ◽

High Surface ◽

High Surface Area ◽

Biofilm Reactor ◽

Moving Bed Biofilm Reactor ◽

Moving Bed ◽

Printed Media ◽

3D Printed ◽

Very High

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Continuous bioelectricity production and sustainable wastewater treatment in a microbial fuel cell constructed with non-catalyzed granular graphite electrodes and permeable membrane

Water Science & Technology ◽

10.2166/wst.2010.140 ◽

2010 ◽

Vol 61 (7) ◽

pp. 1819-1827 ◽

Cited By ~ 16

Author(s):

Hung-Thuan Tran ◽

Jae-Hun Ryu ◽

Yu-Hong Jia ◽

Se-Jin Oh ◽

Ji-Youn Choi ◽

...

Keyword(s):

Wastewater Treatment ◽

Surface Area ◽

Microbial Fuel Cells ◽

Removal Rate ◽

High Surface ◽

High Surface Area ◽

Organic Loading Rate ◽

Permeable Membrane ◽

Terminal Electron Acceptor ◽

Organic Removal

Oxygen has been so far addressed as the most preferable terminal electron acceptor in the cathodes of microbial fuel cells (MFCs). However, to reduce the oxygen reduction overpotential at the cathode surface, eco-unfriendly and costly catalysts have been commonly employed. Here, we pursued the possibility of using a high surface area electrode to reduce the cathodic reaction overpotential rather than the utilization of catalyzed materials. A dual chambered MFC reactor was designed with the use of graphite-granule electrodes and a permeable membrane. The performance of the reactor in terms of electricity generation and organic removal rate was examined under a continuous-feed manner. Results showed that the maximum volumetric power of 4.4±0.2 W/m3 net anodic compartment (NAC) was obtained at a current density of 11±0.5 A/m3 NAC. The power output was improved by increasing the electrolyte ionic strength. An acceptable effluent quality was attained when the organic loading rate (OLR) of 2 kgCOD/m3 NAC d was applied. The organic removal rate seemed to be less affected by shock loading. Our system can be suggested as a promising approach to make MFC-based technology economically viable for wastewater treatment applications. This study shows that current generation can be remarkably improved in comparison with several other studies using a low-surface-area plain graphite electrode.

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Tenacious Mass Transfer Limitations Drive Catalytic Selectivity during Electrochemical Carbon Dioxide Reduction

10.26434/chemrxiv.7770338.v1 ◽

2019 ◽

Cited By ~ 1

Author(s):

Kailun Yang ◽

Recep Kas ◽

Wilson A. Smith

Keyword(s):

Surface Area ◽

High Surface ◽

High Surface Area ◽

Catalyst Layer ◽

Active Surface ◽

Active Surface Area ◽

High Concentration ◽

Copper Electrodes ◽

Surface Enhanced ◽

Local Current

This study evaluated the performance of the commonly used strong buffer electrolytes, i.e. phosphate buffers, during CO2 electroreduction in neutral pH conditions by using in-situ surface enhanced infrared absorption spectroscopy (SEIRAS). Unfortunately, the buffers break down a lot faster than anticipated which has serious implications on many studies in the literature such as selectivity and kinetic analysis of the electrocatalysts. Increasing electrolyte concentration, surprisingly, did not extend the potential window of the phosphate buffers due to dramatic increase in hydrogen evolution reaction. Even high concentration phosphate buffers (1 M) break down within the potentials (-1 V vs RHE) where hydrocarbons are formed on copper electrodes. We have extended the discussion to high surface area electrodes by evaluating electrodes composed of copper nanowires. We would like highlight that it is not possible to cope with high local current densities on these high surface area electrodes by using high buffer capacity solutions and the CO2 electrocatalysts are needed to be evaluated by casting thin nanoparticle films onto inert substrates as commonly employed in fuel cell reactions and up to now scarcely employed in CO2 electroreduction. In addition, we underscore that normalization of the electrocatalytic activity to the electrochemical active surface area is not the ultimate solution due to concentration gradient along the catalyst layer.This will “underestimate” the activity of high surface electrocatalyst and the degree of underestimation will depend on the thickness, porosity and morphology of the catalyst layer.

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