scholarly journals Evaluation of the biogas potential of a lignocellulosic residue

Author(s):  
Nardjes Guendouz ◽  
Hynda Rezzaz-Yazid ◽  
Salima Laib ◽  
Zahra Sadaoui

Abstract Anaerobic digestion (AD) or methanization is a biological process that allows the treatment of organic wastes and the production of renewable energy as biogas. This research describes assessment and optimization of dates pedicels rich in organic components under the conditions of mesophiles in co-digestion in association with the cattle manure and sludge of the wastewater treatment plant (WWTP). To realize this objectives, we investigated the impact of substrate load (date pedicel) on the co-digestion anaerobic of date pedicels and the sludge in wastewater treatment plants. The different parameters of the digester stability such as the pH, VFA, CAT, ammoniacal nitrogen, and the volume of biogas produced were followed. The results show that by increasing the mass of the pedicels and therefore the percentage of the substrate in the reactor, from 0.5 to 1% (W/V), the volume of produced biogas increases by five times. However, an increase in the percentage of the substrate introduced into the digester from 1 to 2% resulted in a slight decrease in the volume of biogas produced. The use of fresh cattle manure as inoculum shown a significant improvement (40%) in the production of biogas, which can be attributed to the nature of the inoculum. Indeed, cattle manure fresh is more adapted for the fermentation of lignocellulosic materials unlike sludge of wastewater treatment plants which may contain toxic substances that limit their use in AD.

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 650 ◽  
Author(s):  
Ioanna Zerva ◽  
Ioanna Alexandropoulou ◽  
Maria Panopoulou ◽  
Paraschos Melidis ◽  
Spyridon Ntougias

Wastewater treatment plants (WWTPs) highly contribute to the transmission of antibiotic resistance genes (ARGs) in the environment. In this work, the diversity of ermF, ermB, sul1 and int1-enconding genes was examined in the influent, the mixed liquor and the effluent of a full-scale WWTP. Based on the clones analyzed, similar genotypes were recorded at all process stages. However, distinct genotypes of int1 were responsible for the expression of sul1 and ermF genes in Gammaproteobacteria and Bacteroidetes, respectively. Due to the detection of similar ARGs profiles throughout the biological process, it is concluded that additional treatment is needed for their retention.


2020 ◽  
Vol 13 ◽  
pp. 117862212093585 ◽  
Author(s):  
Karim M Morsy ◽  
Mohamed K Mostafa ◽  
Khaled Z Abdalla ◽  
Mona M Galal

Although significant progress has been achieved in the field of environmental impact assessment in many engineering disciplines, the impact of wastewater treatment plants has not yet been well integrated. In light of this remarkable scientific progress, the outputs of the plants as treated water and clean sludge have become potential sources of irrigation and energy, not a waste. The aim of this study is to assess the environmental impacts of upgrading the wastewater treatment plants from primary to secondary treatment. The Lifecycle Assessment Framework (ISO 14040 and 14044) was applied using GaBi Software. Abu Rawash wastewater treatment plant (WWTP) has been taken as a case study. Two scenarios were studied, Scenario 1 is the current situation of the WWTP using the primary treatment units and Scenario 2 is upgrading the WWTP by adding secondary treatment units. The study highlighted the influence and cumulative impact of upgrading all the primary WWTPs in Egypt to secondary treatment. With the high amount of energy consumed in the aeration process, energy recovery methods were proposed to boost the circular economy concept in Abu Rawash WWTP in order to achieve optimal results from environmental and economic perspectives.


FACETS ◽  
2018 ◽  
Vol 3 (1) ◽  
pp. 128-138 ◽  
Author(s):  
Claire N. Freeman ◽  
Lena Scriver ◽  
Kara D. Neudorf ◽  
Lisbeth Truelstrup Hansen ◽  
Rob C. Jamieson ◽  
...  

Wastewater treatment plants (WWTPs) have been identified as hotspots for antimicrobial resistance genes (ARGs) and thus represent a critical point where patterns in ARG abundances can be monitored prior to their release into the environment. The aim of the current study was to measure the impact of the release of the final treated effluent (FE) on the abundance of ARGs in the receiving water of a recently upgraded WWTP in the Canadian prairies. Sample nutrient content (phosphorous and nitrogen species) was measured as a proxy for WWTP functional performance, and quantitative PCR (qPCR) was used to measure the abundance of eight ARGs, the intI1 gene associated with class I integrons, and the 16S rRNA gene. The genes ermB, sul1, intI1, blaCTX-M, qnrS, and tetO all had higher abundances downstream of the WWTP, consistent with the genes with highest abundance in the FE. These findings are consistent with the increasing evidence suggesting that human activity affects the abundances of ARGs in the environment. Although the degree of risk associated with releasing ARGs into the environment is still unclear, understanding the environmental dimension of this threat will help develop informed management policies to reduce the spread of antibiotic resistance and protect public health.


2014 ◽  
Vol 69 (7) ◽  
pp. 1359-1372 ◽  
Author(s):  
Oskar Modin ◽  
David J. I. Gustavsson

Microbial bioelectrochemical systems (BESs) utilize living microorganisms to drive oxidation and reduction reactions at solid electrodes. BESs could potentially be used at municipal wastewater treatment plants (WWTPs) to recover the energy content of organic matter, to produce chemicals useful at the site, or to monitor and control biological treatment processes. In this paper, we review bioelectrochemical technologies that could be applied for municipal wastewater treatment. Sjölunda WWTP in Malmö, Sweden, is used as an example to illustrate how the different technologies potentially could be integrated into an existing treatment plant and the impact they could have on the plant's utilization of energy and chemicals.


Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 100
Author(s):  
Horia Andrei ◽  
Cristian Andrei Badea ◽  
Paul Andrei ◽  
Filippo Spertino

Wastewater treatment plants and power generation constitute inseparable parts of present society. So the growth of wastewater treatment plants is accompanied by an increase in the energy consumption, and a sustainable development implies the use of renewable energy sources on a large scale in the power generation. A case study of the synergy between wastewater treatment plants and photovoltaic systems, aiming to improve the energetic, environmental and economic impacts, is presented. Based on data acquisition, the energy consumption analysis of wastewater treatment plant reveals that the highest demand is during April, and the lowest is during November. The placement of photovoltaic modules is designed to maximize the use of free space on the technological area of wastewater treatment plant in order to obtain a power output as high as possible. The peak consumption of wastewater treatment plant occurs in April, however the peak production of the photovoltaic is in July, so electrochemical batteries can partly compensate for this mismatch. The impact of the photovoltaic system connectivity on power grid is assessed by means of the matching-index method and the storage battery significantly improves this parameter. Carbon credit and energy payback time are used to assess the environmental impact. The results prove that the photovoltaic system mitigates 12,118 tons of carbon and, respectively, the embedded energy is compensated by production in 8 ½ years. The economic impact of the photovoltaic system is analyzed by the levelized cost of energy, and the results show that the price of energy from the photovoltaic source is below the current market price of energy.


2006 ◽  
Vol 54 (8) ◽  
pp. 93-100 ◽  
Author(s):  
E.I.P. Volcke ◽  
K.V. Gernaey ◽  
D. Vrecko ◽  
U. Jeppsson ◽  
M.C.M. van Loosdrecht ◽  
...  

In wastewater treatment plants (WWTPs) equipped with sludge digestion and dewatering systems, the reject water originating from these facilities contributes significantly to the nitrogen load of the activated sludge tanks, to which it is typically recycled. In this paper, the impact of reject water streams on the performance of a WWTP is assessed in a simulation study, using the Benchmark Simulation Model no. 2 (BSM2), that includes the processes describing sludge treatment and in this way allows for plant-wide evaluation. Comparison of performance of a WWTP without reject water with a WWTP where reject water is recycled to the primary clarifier, i.e. the BSM2 plant, shows that the ammonium load of the influent to the primary clarifier is 28% higher in the case of reject water recycling. This results in violation of the effluent total nitrogen limit. In order to relieve the main wastewater treatment plant, reject water treatment with a combined SHARON-Anammox process seems a promising option. The simulation results indicate that significant improvements of the effluent quality of the main wastewater treatment plant can be realized. An economic evaluation of the different scenarios is performed using an Operating Cost Index (OCI).


2005 ◽  
Vol 51 (1) ◽  
pp. 81-88 ◽  
Author(s):  
C. Beck ◽  
G. Prades ◽  
A.-G. Sadowski

The principal objective of our study was to optimise a municipal activated sludge wastewater treatment plant (WWTP) to face high organic flows due to viticulture effluents inputs. Treatment file optimization consisted in testing different treatment lines, changing the number and volume of biological basins and clarifiers, with or without a buffer basin upstream, with a view to achieving a better reduction of COD. The actual WWTP biological stage is composed of two aerated basins whose total volume is 1365 m3. The studied cases are successively, the installation of a single basin of 1365 m3, then of several basins whose total volume remains constant and equal to 1365 m3. Another case was also considered, that of an aerated basin followed by a first clarifier and then, by another aerated basin and a second clarifier. All scenarios presented below were evaluated, for standard dry weather conditions and for high organic load conditions, as encountered during the grape harvest period. The method used was to carry out various simulations, using numerical modelling, and to compare the impact of different process line scenarios and management strategies on the activated sludge WWTP efficiencies.


2010 ◽  
Vol 2 (5) ◽  
pp. 97-102
Author(s):  
Ala Sokolova ◽  
Mindaugas Rimeika

The paper analyzes the impact of the way of mounting a tube diffuser, the design of an aeration tank and the presence of a fixed carrier on the operational parameters of aeration systems used in small wastewater treatment plants. It was found out that the vertically mounted tube diffuser decreased standard oxygen transfer rate (SOTR) of the aeration system by approximately 20% and standard oxygen transfer efficiency (SOTE) by 25% comparing to the horizontally mounted tube diffuser. It was also defined that the design of the aeration tank might have an impact on the operation parameters of the aeration system: when the centre shell used to protect a diffuser was dismantled from a test tank, SOTR and SOTE increased by approximately 20%. It was also established that the presence of the fixed carrier in the aeration tank did not have an impact on the performance of aeration systems. Finally, research was carried out to compare the operational parameters of two diffusers of different types offered on the market and used in small wastewater treatment plants. It was found out that the performance different type diffusers might vary considerably.


Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 598 ◽  
Author(s):  
Tomáš Vítěz ◽  
Monika Vítězová ◽  
Markéta Nováčková ◽  
Ivan Kushkevych

Ensuring high quality drinking water sources is important task nowadays. To reach this task, knowledge about the impact of different chemicals on aerobic wastewater treatment is mandatory. A mixture of different chemicals reaches wastewater treatment plant every day. With the growing discharge volume of mobile toilet chemicals, active substances in these products in the past years have been recorded. The respiratory activity of activated sludge was determined to show how mobile toilet chemicals and their active substances may affect the biological wastewater treatment process. The results show negative effect of formaldehyde and bronopol on respiratory activity of activated sludge. The wastewater treatment plants influent composition and size also play important roles. Results shows that activated sludge microorganisms at a wastewater treatment plant in industrial urban area may be adapted to the higher pollutants concentration. When mobile toilet tanks are directly discharged at smaller wastewater treatment plant, an activated sludge process can be affected. For treating mobile toilet wastewater, bacterial degraders can be used. During our respiratory activity experiments, potential degraders were searched. Ralstonia sp. prevails in all samples and it is therefore a potential mobile toilet chemicals degrader.


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