scholarly journals Biodrying of the Light Fraction from Anaerobic Digestion Pretreatment in Order to Increase the Total Recovery Rate

Processes ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 276 ◽  
Author(s):  
Isabella Pecorini ◽  
Donata Bacchi ◽  
Renato Iannelli
Keyword(s):  
Anaerobic Digestion ◽  
Pilot Scale ◽  
Light Fraction ◽  
Total Recovery ◽  
Heating Value ◽  
Lower Heating Value ◽  
Average Water ◽  
Pre Treatment ◽  
Refuse Derived Fuels ◽  
Short Time

Two pilot-scale tests were carried out to assess if biodrying could be an effective process for the treatment of light fraction produced by an hydromechanical pre-treatment in an anaerobic digestion plant. The trials were performed using two pilot-scale stainless steel cylindrical reactors of 750 L capacity. Two tests were performed: in Test 1, only the light fraction was used; in Test 2, the light fraction was mixed with a bulking agent composed of garden and pruning waste. In Test 2, the highest temperature (71 °C) in a short time (8 days) was reached. An average water content reduction of 78% in Test 1 and 61% in Test 2 was measured, leading to similar reductions of weight (47–48%) and volume (27–29%). A high biological stability was measured on the final light fraction samples collected from both the tests. Furthermore, the lower heating value obtained after the biodrying treatment complies with the quality specification of the European standard on refuse-derived fuels.

Industrial Process Description for the Recovery of Agricultural Water From Digestate

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Halina Pawlak-Kruczek ◽  
Agnieszka Urbanowska ◽  
Weihong Yang ◽  
Gerrit Brem ◽  
Aneta Magdziarz ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Rural Areas ◽  
Reclaimed Water ◽  
Industrial Process ◽  
Hydrothermal Carbonization ◽  
Full Potential ◽  
Agricultural Water ◽  
Heating Value ◽  
Lower Heating Value ◽  
Lower Heating

Abstract Currently, the reclamation and reuse of water have not reached their full potential, although more energy is needed to obtain and transport freshwater and this solution has a more serious environmental impact. Agricultural irrigation is, by far, the largest application of reclaimed water worldwide, so the proposed concept may result in the production of water that can be used, among others, for crop irrigation. This paper describes a novel installation for the recovery of the agricultural water from the digestate, along with the results of initial experiments. Currently, water is wasted, due to evaporation, in anaerobic digestion plants, as the effluent from dewatering of the digestate is discharged into lagoons. Moreover, water that stays within the interstitial space of the digestate is lost in a similar fashion. With increasing scarcity of water in rural areas, such waste should not be neglected. The study indicates that hydrothermal carbonization (HTC) enhances mechanical dewatering of the agricultural digestate and approximately 900 L of water can be recovered from one ton. Dewatered hydrochars had a lower heating value of almost 10 MJ/kg, indicating the possibility of using it as a fuel for the process. The aim of this Design Innovation Paper is to outline the newly developed concept of an installation that could enable recovery of water from, so far, the neglected resource—i.e., digestate from anaerobic digestion plants.

Ultrasound pre-treatment for anaerobic digestion improvement

2009 ◽  
Vol 60 (6) ◽  
pp. 1525-1532 ◽  
Author(s):  
S. Pérez-Elvira ◽  
M. Fdz-Polanco ◽  
F. I. Plaza ◽  
G. Garralón ◽  
F. Fdz-Polanco
Keyword(s):  
Anaerobic Digestion ◽  
Energy Balance ◽  
Specific Energy ◽  
Biogas Production ◽  
Pilot Scale ◽  
Laboratory Scale ◽  
Net Generation ◽  
Batch Reactors ◽  
Anaerobic Reactors ◽  
Pre Treatment

Prior research indicates that ultrasounds can be used in batch reactors as pre-treatment before anaerobic digestion, but the specific energy required at laboratory-scale is too high. This work evaluates both the continuous ultrasound device performance (efficiency and solubilisation) and the operation of anaerobic digesters continuously fed with sonicated sludge, and presents energy balance considerations. The results of sludge solubilisation after the sonication treatment indicate that, applying identical specific energy, it is better to increase the power than the residence time. Working with secondary sludge, batch biodegradability tests show that by applying 30 kWh/m3 of sludge, it is possible to increase biogas production by 42%. Data from continuous pilot-scale anaerobic reactors (V=100 L) indicate that operating with a conventional HRT = 20 d, a reactor fed with pre-treated sludge increases the volatile solids removal and the biogas production by 25 and 37% respectively. Operating with HRT = 15 d, the removal efficiency is similar to the obtained with a reactor fed with non-hydrolysed sludge at HTR = 20 d, although the specific biogas productivity per volume of reactor is higher for the pretreated sludge. Regarding the energy balance, although for laboratory-scale devices it is negative, full-scale suppliers state a net generation of 3–10 kW per kW of energy used.

scholarly journals Treatment of By-Products Generated from Anaerobic Digestion of Municipal Solid Waste

2019 ◽  
Vol 11 (9) ◽  
pp. 4933-4940 ◽  
Author(s):  
Przemysław Seruga ◽  
Małgorzata Krzywonos ◽  
Marta Wilk
Keyword(s):  
Anaerobic Digestion ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Ph Value ◽  
Pilot Scale ◽  
Air Stripping ◽  
Liquid Digestate ◽  
Initial Ph ◽  
Pre Treatment ◽  
By Products

Abstract Purpose This study aimed to examine the possibilities of the treatment of the by-products generated in the anaerobic digestion (AD) of the organic fraction of municipal solid waste (OFMSW): oxygen stabilization (composting) of the solid digestate and pretreatment with air stripping of the effluents (liquid digestate and leachate from maturation field and reactors from composting). Methods Oxygen stabilization (OS) was performed in full-scale in a mechanical–biological treatment (MBT) plant using three different methods, using an open field or enclosed box reactor with aeration. The ammonia stripping was performed in a pilot-scale installation using effluents from AD (liquid digestate) and OS (leachate from maturation field and reactors). Results The lowest self-heating possibility after the OS was recorded at 28.5 °C, which proves that the most stabilized was the sample after processing with structuring material addition. Due to air stripping, the highest efficiency of ammonium ions removal was noted at the level of 50.6%, with an initial pH value of 10.5, after 12 h. Among the examined factors pH value was found to be significant [the determination coefficient (R2) of 0.93]. Conclusions The oxygen stabilization of the digestate requires the structuring material addition before being placed in the reactor with aeration. The inert fraction from the ballistic separation of the OFMSW can be an interesting solution, as required structuring material. Air stripping as the effluents pre-treatment step can meet the MBT plants expectations. Graphic Abstract

Influence of microwave pre-treatment on sludge solubilization and pilot scale semi-continuous anaerobic digestion

2013 ◽  
Vol 128 ◽  
pp. 598-603 ◽  
Author(s):  
Lise Appels ◽  
Sofie Houtmeyers ◽  
Jan Degrève ◽  
Jan Van Impe ◽  
Raf Dewil
Keyword(s):  
Anaerobic Digestion ◽  
Pilot Scale ◽  
Pre Treatment

Effect of thermal hydrolysis pre-treatment on anaerobic digestion of municipal biowaste: A pilot scale study in China

2013 ◽  
Vol 116 (1) ◽  
pp. 101-105 ◽  
Author(s):  
Yingjun Zhou ◽  
Masaki Takaoka ◽  
Wei Wang ◽  
Xiao Liu ◽  
Kazuyuki Oshita
Keyword(s):  
Anaerobic Digestion ◽  
Pilot Scale ◽  
Thermal Hydrolysis ◽  
Pre Treatment

Digestion of sludge and organic waste in the sustainability concept for Malmö, Sweden

2004 ◽  
Vol 49 (10) ◽  
pp. 163-169 ◽  
Author(s):  
J. la Cour Jansen ◽  
C. Gruvberger ◽  
N. Hanner ◽  
H. Aspegren ◽  
 Svärd
Keyword(s):  
Anaerobic Digestion ◽  
Organic Waste ◽  
Biogas Production ◽  
Treatment Plant ◽  
Pilot Scale ◽  
Anaerobic Treatment ◽  
Household Waste ◽  
Biogas Yield ◽  
Different Types ◽  
Pre Treatment

Anaerobic digestion of sludge has been part of the treatment plant in Malmö for many years and several projects on optimisation of the digestion process have been undertaken in full scale as well as in pilot scale. In order to facilitate a more sustainable solution in the future for waste management, solid waste organic waste is sorted out from households for anaerobic treatment in a newly built city district. The system for treatment of the waste is integrated in a centralised solution located at the existing wastewater treatment plant. A new extension of the digester capacity enables separate as well as co-digestion of sludge together with urban organic waste from households, industry, restaurants, big kitchens, food stores, supermarkets, green markets etc. for biogas production and production of fertiliser. Collection and pre-treatment of different types of waste are in progress together with examination of biogas potential for different types of organic waste. Collection of household waste as well as anaerobic digestion in laboratory and pilot scale has been performed during the last year. It is demonstrated that organic household waste can be digested separately or in combination with sludge. In the latter case a higher biogas yield is found than should be expected from digestion of the two materials separately. Household waste from a system based on collection of organic waste from grinders could be digested at mesophilic conditions whereas digestion failed at thermophilic conditions.

Comparative study of domestic wastewater treatment efficiencies between facultative pond and water spinach pond

1995 ◽  
Vol 32 (3) ◽  
pp. 263-270 ◽  
Author(s):  
Seni Karnchanawong ◽  
Jaras Sanjitt
Keyword(s):  
Growth Rates ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
Organic Content ◽  
Water Spinach ◽  
Removal Rates ◽  
Mass Removal ◽  
Loading Rates ◽  
Tropical Conditions ◽  
Average Water

Two pilot-scale studies were comparatively conducted under tropical conditions during December 1992 to September 1993. One study involved facultative ponds(FP) and the others water spinach ponds(SP). Four rectangular concrete ponds, 0.8 m × 2.4 m × 1.1 m (width × length × depth), were employed to treat the Chiang Mai University campus wastewater. Water spinach (Ipomoea aquatica) was planted in two of the ponds. The influent characteristics noted showed a low organic content, i.e. BOD 25.4-29.9 mg/l, with BOD:N ratio around 1:1. The investigations were conducted using the following hydraulic retention times (HRT): 1.6, 2, 2.7, 4, 8 and 16 d. The results showed that the BOD, COD and SS mass removal rates increased as the mass loading rates increased and the SP was significantly more effective in reducing the organic content than the FP. No relationship was found between TN mass removal and the loading rates. However, the TP mass removal rates in the SP and the FP were rather low and were considered to be insignificant. It was observed that SS accumulated in the water spinach root systems which tended to act as a strainer. This process led to plant growth inhibition and finally die-off. The average water spinach growth rates varied from 37 to 107 g wet wt./(m2.d) and no relationship was established between the growth rates and the HRT.

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.

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