scholarly journals A STUDY ON RENEWABLE ENERGY SOURCES AND MICROBIAL FUEL CELLS

2016 ◽  
Vol 2 (7) ◽  
Author(s):  
S Venkata Raju ◽  
K Madhusudhana

Renewable energy is the energy created by sources, which are naturally replenished such as sunlight, rain, wind and tides. Although there is much debate about how  to define and distinguish renewable energy from non-renewable, other energy types such as biomass, biofuel and anaerobic digestion are also widely considered as renewable energy. Microbial fuel cells(MFCs) that generate electricity by the break-down of organic matter(e.g. wastewater) have a great potential for the future energy and environmental challenges. MFCs are often compared with anaerobic digestion, which also uses microbial activity for breaking down organic matter in the absence of oxygen. Unlike anaerobic digestion, which is relatively well understood and already widely used in municipal wastewater treatment plants, MFCs have received far less attention and funding, hence the technology is still at laboratory level in its development.

2004 ◽  
Vol 49 (2) ◽  
pp. 191-199 ◽  
Author(s):  
J.B. Neethling ◽  
M. Benisch

Struvite deposition is a common problem in municipal wastewater treatment plants and can be signi?cant if not anticipated, but struvite deposits are completely manageable if properly addressed. This paper summarises experiences from a number of facilities that have dealt successfully with struvite problems, elaborates on the interrelations between secondary treatment and anaerobic digestion, and outlines an approach to control struvite and available alternatives.


2006 ◽  
Vol 54 (4) ◽  
pp. 119-128 ◽  
Author(s):  
M.S. Fountoulakis ◽  
K. Stamatelatou ◽  
D.J. Batstone ◽  
G. Lyberatos

Di-ethylhexyl phthalate (DEHP) has commonly been found in the sludge of municipal wastewater treatment plants especially during anaerobic processing. It is slowly biodegradable under anaerobic conditions. Due to its high hydrophobicity, sorption-desorption processes can be rate-limiting for the compound biodegradation. In this study, the anaerobic biodegradation of DEHP was investigated through batch kinetic experiments and dynamic transitions of a continuous stirred tank reactor (CSTR) fed with secondary sludge contaminated with DEHP. A widely accepted model (ADM1) was used to fit the anaerobic digestion of secondary sludge and was properly extended to account for DEHP removal, in which mass transfer processes are also involved. It was shown that DEHP removal was limited by the transfer of DEHP within the solid fraction. The criterion selected for the distinction of the two sites was whether the compound sorbed in those sites was bioavailable for biodegradation or not. Thus, the aqueous phase and the surface of the biosolids were considered as suitable sites for the compound to be bioavailable and the main bulk of the solid matrix was regarded as sites, where the compound remains “protected” against biodegradation. The model, fitted to the batch experimental data, was able to predict DEHP removal in the CSTR operated at various HRTs.


2005 ◽  
Vol 5 (1) ◽  
pp. 51-57 ◽  
Author(s):  
K.H. Ahn ◽  
K.Y. Park ◽  
S.K. Maeng ◽  
K.G. Song ◽  
K.P. Kim ◽  
...  

Reuse of wastewater effluents from secondary treatment processes in municipal wastewater treatment plants has been issued because of substantial volumes of relatively clean waters. The major components of criteria for wastewater reclamations are color, organic matter, and pathogens. An advanced oxidation process with low-pressure ultraviolet and hydrogen peroxide addition (UV/H2O2 system) has been employed for removal of the major components in the criteria for reuse of wastewater. Sand filter pretreatment was applied to remove turbidity and to improve performance of UV irradiation. The results showed that total coliforms were effectively inactivated by the UV irradiation alone with the contact time of 30 minutes but color was remained. The addition of H2O2 significantly improved the removal of color and dissolved organic matter in the same contact time.


2021 ◽  
Author(s):  
◽  
Tolulope Adewale Kudoro

Hydropower is a source of renewable energy. It is possible to combine a hydropower installation with an existing wastewater plant while ensuring it still performs its basic purpose. The multipurpose scheme would be integrated into the facility to generate hydropower while also fulfilling its primary role of treating wastewater. The wastewater plant can generate renewable energy and benefit from introducing microturbines. The turbine system is moved by the power in the flowing treated water that is transformed into mechanical energy which rotates the generator and in turn generates electrical power. In this work, the potential for power generation from the energy in the outflow along with the economics of the system in wastewater plants in the state of Missouri was investigated to improve the energy efficiency of the municipal wastewater treatment plants. Data like the daily flow rate, speed of flow, available head, etc about the wastewater plants in Missouri were collected and some interviews held with plant managers of the wastewater treatment plants. The investigation revealed that there are 127 wastewater treatment plants in the state of Missouri with 32 plants discharging less than 1 Mgd, 74 plants discharging between 1 Mgd and 5 Mgd, 13 plants discharging between 5 Mgd and 20 Mgd while just 8 plants had an outflow between 20 Mgd and 120 Mgd range. The flowrate helps in calculating and determining the theoretical and actual amount of power that can be gotten from the micro hydropower system in the wastewater treatment plant. For the actual amount of power gotten, the efficiency factor (efficiency of the turbine, and efficiency of the generator) of the generating system is considered. A brief study on the turbine system was conducted and a crossflow turbine was selected as the most suitable for the wastewater treatment plant as a vast majority of them had low head and high flow capacity. The analysis showed that out of the 127 wastewater treatment plants in the state of Missouri, only 21 treatment plants have the maximum potential to generate power and reduce operating costs. Also, two plants were selected for case studies. The operating cost is reduced because of the decrease in demand for electrical power from the grid. The 21 treatment plants have a daily outflow between 5Mgd to 120Mgd and could produce power through an axial flow turbine that utilizes the kinetic energy in the flow volume.


2019 ◽  
Vol 6 (3) ◽  
pp. 179-184
Author(s):  
Seyed Mostafa Aghili ◽  
Nasser Mehrdadi ◽  
Behnoush Aminzadeh ◽  
Mohammad Ali Zazouli

Background: One of the useful applications of Dewatered sludge (DWS) of municipal wastewater treatment plants (WWTPs) is its use as manure in agriculture; therefore, its quality characteristics should be specified. The aim of this research was to determine biological and physicochemical characteristics of DWS of Sari WWTP and compare them with standards, and also to investigate its potential use in agriculture. Methods: Sludge samples were taken from the sewage sludge of Sari WWTP. Sampling and analysis of samples parameters including fecal coliform, salmonella, helminth ova, carbon, nitrogen, C/N, phosphorus, organic matter, potassium, moisture, electrical conductivity, and PH, were performed during four seasons with three replications based on the standard method. Results: The fecal coliform, salmonella, and helminth ova of the DWS were 2.37×106 ± 1.06×106 MPN/1 g d.s weight, 47±12.92 MPN/4 g d.s weight, and 466±61.85 number/4 g d.s weight, respectively, therefore, the DWS of Sari WWTP was categorized in the class B of the EPA standard. The amounts of C/N, organic matter, carbon, nitrogen, phosphorus, potassium, moisture, electrical conductivity, and PH were obtained to be 12.7±1.15, 42.4±3.27%, 24.6±1.89%, 1.94±0.13%, 2.35±0.6%, 0.57±0.13%, 82±3.12%, 1.34±0.21 ds/m, and 7.41± 0.45, respectively. Conclusion: The DWS of Sari WWTP has a good fertility value but it cannot be safely used in agriculture and should be improved for class A by the Processes to Further Reduce Pathogens (PFRP), especially by composting.


2013 ◽  
Vol 68 (11) ◽  
pp. 2391-2396 ◽  
Author(s):  
Chang Min Park ◽  
John T. Novak

The role of iron addition to sewage sludge prior to anaerobic digestion was evaluated to determine the effect of iron on digestion performance and generation of odor-causing compounds. Hydrogen sulfide (H2S) and volatile organic sulfur compounds (VOSCs) were the odorous gases evaluated in this study. Samples were obtained from seven municipal wastewater treatment plants (WWTPs), and batch anaerobic digestion tests were conducted using primary and secondary sludges at 30 day solids retention time (SRT) under mesophilic conditions. Volatile solid removal (VSR) was highly predictable with background iron concentrations measured in the combined sludge. They were likely to increase as influent iron content increased. 1.25% w/w ferric chloride (FeCl3) was added to the anaerobic digester feed in order to simulate iron addition for sulfide control in full-scale WWTPs. The results showed that it had a positive impact on digestion performance with higher VSR and odor control with reduced H2S and TVOSCs in the headspace gas of dewatered biosolids considered in the tests. Ferric chloride is considered a beneficial additive as a strategy for an odor mitigation, not to mention more efficient digestion under anaerobic conditions.


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