The effect of direct addition of iron(III) on anaerobic digestion efficiency and odor causing compounds

2013 ◽  
Vol 68 (11) ◽  
pp. 2391-2396 ◽  
Author(s):  
Chang Min Park ◽  
John T. Novak
Keyword(s):  
Anaerobic Digestion ◽  
Ferric Chloride ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Positive Impact ◽  
Municipal Wastewater Treatment ◽  
Organic Sulfur Compounds ◽  
Solids Retention ◽  
Municipal Wastewater Treatment Plants ◽  
Iron Addition

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.

Struvite control through process and facility design as well as operation strategy

2004 ◽  
Vol 49 (2) ◽  
pp. 191-199 ◽  
Author(s):  
J.B. Neethling ◽  
M. Benisch
Keyword(s):  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Secondary Treatment ◽  
Operation Strategy ◽  
Municipal Wastewater Treatment ◽  
Facility Design ◽  
Municipal Wastewater Treatment Plants

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.

Simulation of DEHP biodegradation and sorption during the anaerobic digestion of secondary sludge

2006 ◽  
Vol 54 (4) ◽  
pp. 119-128 ◽  
Author(s):  
M.S. Fountoulakis ◽  
K. Stamatelatou ◽  
D.J. Batstone ◽  
G. Lyberatos
Keyword(s):  
Anaerobic Digestion ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Solid Matrix ◽  
Continuous Stirred Tank Reactor ◽  
Municipal Wastewater Treatment ◽  
Secondary Sludge ◽  
Mass Transfer Processes ◽  
Municipal Wastewater Treatment Plants ◽  
Ethylhexyl Phthalate

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.

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

2016 ◽  
Vol 2 (7) ◽  
Author(s):  
S Venkata Raju ◽  
K Madhusudhana
Keyword(s):  
Organic Matter ◽  
Renewable Energy ◽  
Fuel Cells ◽  
Anaerobic Digestion ◽  
Microbial Fuel Cells ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Renewable Energy Sources ◽  
Municipal Wastewater Treatment ◽  
Municipal Wastewater Treatment Plants

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.

Effects of the membrane technology of the dimensioning of municipal wastewater treatment plants

1998 ◽  
Vol 38 (3) ◽  
pp. 173-178
Author(s):  
A. Seyfried ◽  
E. Dorgeloh ◽  
E. Brands ◽  
P. Ohle
Keyword(s):  
Heavy Metals ◽  
Activated Sludge ◽  
Lower Energy ◽  
Membrane Filtration ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Activated Sludge Process ◽  
Municipal Wastewater Treatment ◽  
Solids Retention ◽  
Municipal Wastewater Treatment Plants

The successful application of membrane filtration on the activated sludge process is a recent development. Two processes are most common: separate modules and submerged modules, with the former being the more promising due to the lower energy consumption. While they allow high sludge ages, conventional sludge ages are equally viable, thus allowing the use of tested and reliable dimensioning techniques. The near perfect solids retention of the membrane filtration, however, can lead to problems with the accumulation of inert solids and heavy metals in the activated sludge. In that area, further research is necessary to develop safe dimensioning methods.

scholarly journals Modification of municipal wastewater for improved biogas recovery

2020 ◽  
Vol 15 (3) ◽  
pp. 683-696
Author(s):  
Vaileth Hance ◽  
Thomas Kivevele ◽  
Karoli Nicholas Njau
Keyword(s):  
Anaerobic Digestion ◽  
Energy Demand ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Organic Content ◽  
Municipal Wastewater Treatment ◽  
Naoh Solution ◽  
Municipal Wastewater Treatment Plants

Abstract The energy demand, which is expected to increase more worldwide, has sparked the interest of researchers to find sustainable and inexpensive sources of energy. This study aims to integrate an energy recovering step into municipal wastewater treatment plants (MWWTPS) through anaerobic digestion. The anaerobic digestion of municipal wastewater (MWW), and then co-digestion with sugar cane molasses (SCM) to improve its organic content, was conducted at 25 °C and 37 °C. The results showed a substrate mixture containing 6% of SCM and total solids (TS) of 7.52% yielded a higher amount of biogas (9.73 L/L of modified substrate). However, chemical oxygen demand (COD) of the resulting digestate was high (10.1 g/L) and pH was not stable, and hence needed careful adjustment using 2 M of NaOH solution. This study recommends a substrate mixture containing SCM (2%) and TS (4.34%) having biogas production (4.97 L/L of modified substrate) for energy recovery from MWWTPS, since it was found to have more stable pH and low COD residue (1.8 g/L), which will not hold back the MWW treatment process. The annual generation of modified substrate (662,973 m3) is anticipated to generate about 16,241 m3 of methane, which produces up to 1.8 GWh and 8,193 GJ per annum.

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