Pre-treatment options for halophytic microalgae and associated methane production

2015 ◽  
Vol 177 ◽  
pp. 410-413 ◽  
Author(s):  
Andrew Ward ◽  
David Lewis
Keyword(s):  
Methane Production ◽  
Treatment Options ◽  
Pre Treatment

scholarly journals Efficiency of integrated electrooxidation and anaerobic digestion of waste activated sludge

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
J. A. Barrios ◽  
A. Cano ◽  
F. F. Rivera ◽  
M. E. Cisneros ◽  
U. Durán
Keyword(s):  
Anaerobic Digestion ◽  
Current Density ◽  
Methane Production ◽  
Energy Recovery ◽  
Energy Analysis ◽  
Mathematical Optimization ◽  
Waste Activated Sludge ◽  
Bdd Electrode ◽  
Vs Removal ◽  
Pre Treatment

Abstract Background Most of the organic content of waste activated sludge (WAS) comprises microbial cells hard to degrade, which must be pre-treated for energy recovery by anaerobic digestion (AD). Electrooxidation pre-treatment (EOP) with boron-doped diamond (BDD) electrode have been considered a promising novel technology that increase hydrolysis rate, by the disintegrating cell walls from WAS. Although electrochemical oxidation could efficiently solubilize organic substances of macromolecules, limited reports are available on EOP of WAS for improving AD. In this endeavour, the mathematical optimization study and the energy analysis of the effects of initial total solids concentrations [TS] of WAS and current density (CD) during EOP on the methane production and removal of chemical oxygen demand (COD) and volatile solids (VS) were investigated. Because limited reports are available on EOP of WAS for improving biogas production, it is not well understood; however, it has started to attract interest of scientists and engineers. Results In the present work, the energy recovery as biogas and WAS conversion were comprehensively affected by CD and [TS], in an integrated EOP and AD system. When working with WAS at 3% of [TS] pre-treated at current density of 24.1 mA/cm2, the highest COD and VS removal were achieved, making it possible to obtain the maximum methane (CH4) production of 305 N-L/kg VS and a positive energy balance of 1.67 kWh/kg VS. Therefore, the current densities used in BDD electrode are adequate to produce the strong oxidant (hydroxyl radical, ·OH) on the electrode surface, allow the oxidation of organic compounds that favours the solubilization of particulate matter and VS from WAS. Conclusions The improvement of VS removal and COD solubilization were due to the effects of pre-treatments, which help to break down the microbial cells for faster subsequent degradation; this allows a decomposition reaction that leads to biodegrade more compounds during AD. The balance was positive, suggesting that even without any optimization the energy used as electricity could be recovered from the increased methane production. It is worth noting that this kind of analysis have not been sufficiently studied so far. It is therefore important to understand how operational parameters can influence the pre-treatment and AD performances. The current study highlights that the mathematical optimization and energy analysis can make the whole process more convenient and feasible.

Soil aquifer treatment using advanced primary effluent

2011 ◽  
Vol 64 (3) ◽  
pp. 640-646 ◽  
Author(s):  
Saroj K. Sharma ◽  
Mustefa Hussen ◽  
Gary Amy
Keyword(s):  
Wastewater Treatment ◽  
Soil Column ◽  
Treatment Options ◽  
Suspended Solid ◽  
Head Loss ◽  
Soil Aquifer Treatment ◽  
Effective Option ◽  
Attractive Option ◽  
Pre Treatment ◽  
Sedimentation Basins

Soil aquifer treatment (SAT) using primary effluent (PE) is an attractive option for wastewater treatment and reuse in many developing countries with no or minimal wastewater treatment. One of the main limitations of SAT of PE is rapid clogging of the infiltration basin due to high suspended solid concentrations. Some pre-treatment of PE before infiltration is likely to reduce this limitation, improve performance of SAT and help to implement this technology effectively. The effects of three pre-treatment options namely sedimentation (SED), coagulation (COAG) and horizontal roughing filtration (HRF) on SAT were analyzed by conducting laboratory-scale batch and soil column experiments. The sedimentation and coagulation pre-treatments led to less head loss development and reduction of clogging effect. The head loss development in soil column using PE + COAG and PE + SED was reduced by 85 and 72%, respectively, compared to PE alone without any pre-treatment. The overall dissolved organic carbon (DOC) removal of pre-treatments and soil column collectively were 34, 44, 51 and 43.5% for PE without any pre-treatment, PE + SED, PE + COAG and PE + HRF, respectively. Coagulation pre-treatment of PE was found to be the most effective option in terms of suspended solids, DOC and nitrogen removal. Sedimentation pre-treatment of PE could be attractive where land is relatively less expensive for the construction of sedimentation basins.

Anaerobic digestion of macroalgae: methane potentials, pre-treatment, inhibition and co-digestion

2011 ◽  
Vol 64 (8) ◽  
pp. 1723-1729 ◽  
Author(s):  
H. B. Nielsen ◽  
S. Heiske
Keyword(s):  
Anaerobic Digestion ◽  
Methane Production ◽  
Organic Content ◽  
Saccharina Latissima ◽  
Green Tides ◽  
Volatile Solids ◽  
Continuously Stirred Tank Reactor ◽  
Pre Treatment ◽  
Centralized Biogas Plant ◽  
Chaetomorpha Linum

In the present study we tested four macroalgae species – harvested in Denmark – for their suitability of bioconversion to methane. In batch experiments (53 °C) methane yields varied from 132 ml g volatile solids−1 (VS) for Gracillaria vermiculophylla, 152 ml g VS−1 for Ulva lactuca, 166 ml g VS−1 for Chaetomorpha linum and 340 ml g VS−1 for Saccharina latissima following 34 days of incubation. With an organic content of 21.1% (1.5–2.8 times higher than the other algae) S. latissima seems very suitable for anaerobic digestion. However, the methane yields of U. lactuca, G. vermiculophylla and C. linum could be increased with 68%, 11% and 17%, respectively, by pretreatment with maceration. U. lactuca is often observed during ‘green tides’ in Europe and has a high cultivation potential at Nordic conditions. Therefore, U. lactuca was selected for further investigation and co-digested with cattle manure in a lab-scale continuously stirred tank reactor. A 48% increase in methane production rate of the reactor was observed when the concentration of U. lactuca in the feedstock was 40% (VS basis). Increasing the concentration to 50% had no further effect on the methane production, which limits the application of this algae at Danish centralized biogas plant.

Free ammonia pre-treatment of secondary sludge significantly increases anaerobic methane production

2017 ◽  
Vol 118 ◽  
pp. 12-19 ◽  
Author(s):  
Wei Wei ◽  
Xu Zhou ◽  
Dongbo Wang ◽  
Jing Sun ◽  
Qilin Wang
Keyword(s):  
Methane Production ◽  
Free Ammonia ◽  
Secondary Sludge ◽  
Pre Treatment

scholarly journals Effects of Thickened Excess Sludge Pre-Treatment Using Hydrodynamic Cavitation for Anaerobic Digestion

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2483 ◽  
Author(s):  
Agnieszka Garlicka ◽  
Monika Zubrowska-Sudol ◽  
Katarzyna Umiejewska ◽  
Otton Roubinek ◽  
Jacek Palige ◽  
...  
Keyword(s):  
Methane Production ◽  
Pilot Scale ◽  
Hydrodynamic Cavitation ◽  
Excess Sludge ◽  
Maximum Increase ◽  
Primary Sludge ◽  
Sludge Flocs ◽  
Pre Treatment ◽  
Flocculation Process ◽  
Different Levels

The main purpose of this study was the assessment of the possibility of increasing the production of biogas through the pre-treatment of thickened excess sludge (TES) by means of the hydrodynamic cavitation (HC) conducted at different levels of energy density (EL) i.e., 70, 140 and 210 kJ/L. The experiments were performed on a pilot scale, and a mixture of thickened primary sludge (TPS) and TES was used as digester feed. The results documented that an important parameter determining the possibility of obtaining an enhanced methane production is the value of energy input in the HC process. This parameter determines the changes occurring in sludge as a result of disintegration (i.e., sludge floc deagglomeration, lysis of cells, re-flocculation process and the related release of compounds susceptible to biodegradation from sludge flocs). The maximum increase in methane yield (MY) of 152% was obtained for EL = 140 kJ/L. In this case, HC mainly caused sludge floc deagglomeration. An increase in MY was also recorded when TES was subject to the disintegration process at EL = 210 kJ/L. However, it was 4.3 times lower than that observed for EL = 140 kJ/L. Pre-treatment of TES at EL = 70 kJ/L did not contribute to an increase in methane production.

scholarly journals Innovative Hydrodynamic Disintegrator Adjusted to Agricultural Substrates Pre-treatment Aimed at Methane Production Intensification—CFD Modelling and Batch Tests

Energies ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 4256 ◽  
Author(s):  
Monika Zubrowska-Sudol ◽  
Aleksandra Dzido ◽  
Agnieszka Garlicka ◽  
Piotr Krawczyk ◽  
Michał Stępień ◽  
...  
Keyword(s):  
Methane Production ◽  
Damage Zone ◽  
Positive Energy ◽  
Net Energy ◽  
Maize Silage ◽  
Cfd Modelling ◽  
Study Objective ◽  
Testing Procedures ◽  
Methane Potential ◽  
Pre Treatment

The study objective was to adjust the hydrodynamic disintegrator dedicated to sewage sludge pre-treatment (HDS) to work with agricultural substrate. This involved the development and implementation of a mathematical model of flow via the device’s domain. An innovative disintegrator (HAD—hydrodynamic disintegrator for agriculture) was designed, built, and tested based on the obtained results. The main improvements to the HDS include the implementation of shredding knives in order to overcome clogging by crushed substrate, and the application of ribs in the recirculation zone, contributing to the development of an additional structure damage zone. The challenge of this study was also to determine the operating parameters of the HDA that would provide for an increase in methane production with positive energy balance. The testing procedures, for which maize silage was selected, involved batch disintegration tests and biochemical methane potential tests. No clogging of rotor or spontaneous shutting off of the device, in other words, problems that had occurred in the HDS, were observed. The applied pre-treatment method permitted an increase in the methane potential of maize silage by 34.4%, 27.0%, and 21.6%, respectively for samples disintegrated at energy densities of 10 kJ/L, 20 kJ/L, and 35 kJ/L with net energy profit.

scholarly journals Upgraded Seawater-Alkaline Pre-Treatment of Lignocellulosic Biomass for Bio-Methane Production

2017 ◽  
Vol 138 ◽  
pp. 372-379
Author(s):  
Shahrul Ismail ◽  
Mizan Qistina Saharuddin ◽  
Mohamed Shahrir Mohamed Zahari
Keyword(s):  
Lignocellulosic Biomass ◽  
Methane Production ◽  
Pre Treatment

scholarly journals Impact of pre-treatment technologies on soil aquifer treatment

2016 ◽  
Vol 7 (1) ◽  
pp. 1-10 ◽  
Author(s):  
A. Besançon ◽  
M. Pidou ◽  
P. Jeffrey ◽  
B. Jefferson ◽  
K. S. Le Corre
Keyword(s):  
Treatment Options ◽  
Infiltration Rate ◽  
Soil Aquifer Treatment ◽  
Operational Conditions ◽  
Conventional Activated Sludge ◽  
Treatment Train ◽  
Pre Treatment ◽  
The One ◽  
The Impact

This study investigates the impact of pre-treatment options on the performances of soil columns simulating soil aquifer treatment (SAT). For this purpose a conventional activated sludge (CAS) process, a membrane bioreactor (MBR) and vertical flow reed beds were used as single units or in combination before SAT. The influent and effluent from each treatment train were monitored over three successive 6-month periods, corresponding to changes in the operational conditions of the MBR and CAS units from 6 days' sludge retention time (SRT) to 12 and 20 days. All the columns acted as efficient polishing steps for solids and bacteria. The column receiving effluent from the CAS system running at 6 days' SRT also presented high total nitrogen and total phosphorus removals, but this column was also associated with the lowest infiltration rates over that period. While the quality of the effluent from the column following the CAS process increased over 18 months of operation, the effluent quality of the columns receiving MBR effluent degraded. No correlations were found between variations in SRT of the MBR and CAS processes and the columns' performances. Overall, all columns, except the one receiving CAS effluent, underwent a reduction in infiltration rate over 18 months.

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