New findings on the anaerobic co-digestion of thermally pretreated sludge and food waste: lab and pilot scale studies

Abstract Co-digestion of thermally pre-treated sewage sludge with food waste is an innovative strategy that could improve the balance and availability of nutrients needed to increase the efficiency of anaerobic digestion in terms of biogas production. In this context, the aim of this research was to evaluate the impact of different proportions of sewage sludge/food waste in lab and pilot scale reactors. Special focus was placed on the impact of the variability of food waste composition on the behavior of the pilot digester. Our results show that by adding 40% of co-substrate, a higher biogas production was possible during laboratory operation. Interestingly, using a co-substrate of variable composition had no negative impact on the reactor's stability at pilot scale, promoting an increase in biogas production through a more efficient use of organic matter. In both the lab and pilot experiences there was an impact on the amount of nitrogen in the digestate compared to digester operating in monodigestion. This impact is more significant as the proportion of cosubstrate rises. Overall, our results show that co-digestion of thermally pretreated sewage sludge with food waste allows better management of food waste, especially when their composition is variable.

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Food Waste Co-Digestion with Microwave Pre-Treated Sewage Sludge to Enhance Biogas Production Through Anaerobic Digestion

2018 International Conference and Utility Exhibition on Green Energy for Sustainable Development (ICUE) ◽

10.23919/icue-gesd.2018.8635752 ◽

2018 ◽

Author(s):

Kumaran Palanisamy ◽

Hephzibah David ◽

Gopinathan Muthaiyah

Keyword(s):

Anaerobic Digestion ◽

Sewage Sludge ◽

Food Waste ◽

Biogas Production ◽

Treated Sewage

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Anaerobic co-digestion of sewage sludge and primary clarifier skimmings for increased biogas production

Water Science & Technology ◽

10.2166/wst.2012.550 ◽

2013 ◽

Vol 67 (1) ◽

pp. 174-179 ◽

Cited By ~ 6

Author(s):

S. Alanya ◽

Y. D. Yilmazel ◽

C. Park ◽

J. L. Willis ◽

J. Keaney ◽

...

Keyword(s):

Water Pollution ◽

Sewage Sludge ◽

Pollution Control ◽

Biogas Production ◽

Control Plant ◽

Treatment Plant ◽

Pilot Scale ◽

Water Pollution Control ◽

Study Results ◽

The Impact

The objective of the study was to identify the impact of co-digesting clarifier skimmings on the overall methane generation from the treatment plant and additional energy value of the increased methane production. Biogas production from co-digesting clarifier skimmings and sewage sludge in pilot-scale fed-batch mesophilic anaerobic digesters has been evaluated. The digester was fed with increasing quantities of clarifier skimmings loads: 1.5, 2.6, 3.5 and 7.0 g COD equivalent/(L·d) (COD: chemical oxygen demand). Average volatile solids reduction of 65% was achieved in the scum-fed digester, compared with 51% in the control digester. Average 69% COD removal was achieved at highest scum loading (7 g COD eq/(L·d)) with approximate methane yield of 250 L CH4/kg COD fed (4 ft3/lb COD fed). The results show that scum as co-substrate in anaerobic digestion systems improves biogas yields while a 29% increase in specific CH4 yield could be achieved when scum load is 7 g COD eq/(L·d). Based on the pilot-scale study results and full-scale data from South East Water Pollution Control Plant and Northeast Water Pollution Control Plant the expected annual energy recovery would be approximately 1.7 billion BTUs or nearly 0.5 million kWh.

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Biogas potential of organic waste onboard cruise ships — a yet untapped energy source

Biomass Conversion and Biorefinery ◽

10.1007/s13399-020-01249-0 ◽

2021 ◽

Author(s):

Kai Schumüller ◽

Dirk Weichgrebe ◽

Stephan Köster

Keyword(s):

Energy Source ◽

Anaerobic Digestion ◽

Sewage Sludge ◽

Food Waste ◽

Energy Demand ◽

Organic Waste ◽

Biogas Production ◽

Biogas Yield ◽

Cruise Ships ◽

Detailed Presentation

AbstractTo tap the organic waste generated onboard cruise ships is a very promising approach to reduce their adverse impact on the maritime environment. Biogas produced by means of onboard anaerobic digestion offers a complementary energy source for ships’ operation. This report comprises a detailed presentation of the results gained from comprehensive investigations on the gas yield from onboard substrates such as food waste, sewage sludge and screening solids. Each person onboard generates a total average of about 9 kg of organic waste per day. The performed analyses of substrates and anaerobic digestion tests revealed an accumulated methane yield of around 159 L per person per day. The anaerobic co-digestion of sewage sludge and food waste (50:50 VS) emerged as particularly effective and led to an increased biogas yield by 24%, compared to the mono-fermentation. In the best case, onboard biogas production can provide an energetic output of 82 W/P, on average covering 3.3 to 4.1% of the total energy demand of a cruise ship.

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Full scale co-digestion of organic waste

Water Science & Technology ◽

10.2166/wst.2000.0072 ◽

2000 ◽

Vol 41 (3) ◽

pp. 195-202 ◽

Cited By ~ 32

Author(s):

H. Kübler ◽

K. Hoppenheidt ◽

P. Hirsch ◽

A. Kottmair ◽

R. Nimmrichter ◽

...

Keyword(s):

Negative Impact ◽

Biogas Production ◽

Electrical Power ◽

Nutrient Content ◽

Primary Energy ◽

Gas Production ◽

Waste Streams ◽

Volatile Solids ◽

Operation Results ◽

The Impact

Operational results of a co-digestion facility were assessed over a period of 18 months. The organic fraction of municipal solid waste (OFMSW) contains a considerable amount of contaminants and grit (up to 6% w/w). A BTA-Pulper efficiently treated the different waste streams and converted a high amount of volatile solids (VS) into the digester feedstock. The seasonal fluctuations of the waste composition significantly influenced the biogas production. The impact of this seasonally variant degradability of VS had to be considered by evaluating the operation results. The waste streams investigated did not show any negative impact on digester performance. The hydraulic retention time (HRT) in the digester considerably affected the VS-reduction. Despite a considerable decrease of VS-degradation a reduction of HRT from 14 to 8 days slightly improves the gas production rate (GPR). An activated sludge system efficiently reduced the pollution of the effluent.The nutrient content of the anaerobic compostwas favourable and the content of pollutants was low. The facility produced surplus electrical power up to 290 MJ/t. An overall energy balance shows that the facility substitutes primary energy.

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Improving biogas production from anaerobic co-digestion of sewage sludge with a thermal dried mixture of food waste, cheese whey and olive mill wastewater

Waste Management ◽

10.1016/j.wasman.2017.08.016 ◽

2018 ◽

Vol 71 ◽

pp. 644-651 ◽

Cited By ~ 43

Author(s):

A.E. Maragkaki ◽

I. Vasileiadis ◽

M. Fountoulakis ◽

A. Kyriakou ◽

K. Lasaridi ◽

...

Keyword(s):

Sewage Sludge ◽

Food Waste ◽

Cheese Whey ◽

Biogas Production ◽

Olive Mill Wastewater ◽

Olive Mill

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Tourism under the Early Phase of COVID-19 in Four APEC Economies: An Estimation with Special Focus on SARS Experiences

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph17207543 ◽

2020 ◽

Vol 17 (20) ◽

pp. 7543

Author(s):

Bao-Linh Tran ◽

Chi-Chung Chen ◽

Wei-Chun Tseng ◽

Shu-Yi Liao

Keyword(s):

Hong Kong ◽

New Zealand ◽

Fixed Effects ◽

Negative Impact ◽

Asia Pacific ◽

International Tourism ◽

Special Focus ◽

Tourism Demand ◽

Data Set ◽

The Impact

This study examines how experience of severe acute respiratory syndrome (SARS) influences the impact of coronavirus disease (COVID-19) on international tourism demand for four Asia-Pacific Economic Cooperation (APEC) economies, Taiwan, Hong Kong, Thailand, and New Zealand, over the 1 January–30 April 2020 period. To proceed, panel regression models are first applied with a time-lag effect to estimate the general effects of COVID-19 on daily tourist arrivals. In turn, the data set is decomposed into two nation groups and fixed effects models are employed for addressing the comparison of the pandemic-tourism relationship between economies with and without experiences of the SARS epidemic. Specifically, Taiwan and Hong Kong are grouped as economies with SARS experiences, while Thailand and New Zealand are grouped as countries without experiences of SARS. The estimation result indicates that the number of confirmed COVID-19 cases has a significant negative impact on tourism demand, in which a 1% COVID-19 case increase causes a 0.075% decline in tourist arrivals, which is a decline of approximately 110 arrivals for every additional person infected by the coronavirus. The negative impact of COVID-19 on tourist arrivals for Thailand and New Zealand is found much stronger than for Taiwan and Hong Kong. In particular, the number of tourist arrivals to Taiwan and Hong Kong decreased by 0.034% in response to a 1% increase in COVID-19 confirmed cases, while in Thailand and New Zealand, a 1% national confirmed cases increase caused a 0.103% reduction in tourism demand. Moreover, the effect of the number of domestic cases on international tourism is found lower than the effect caused by global COVID-19 mortality for the economies with SARS experiences. In contrast, tourist arrivals are majorly affected by the number of confirmed COVID-19 cases in Thailand and New Zealand. Finally, travel restriction in all cases is found to be the most influencing factor for the number of tourist arrivals. Besides contributing to the existing literature focusing on the knowledge regarding the nexus between tourism and COVID-19, the paper’s findings also highlight the importance of risk perception and the need of transmission prevention and control of the epidemic for the tourism sector.

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Anaerobic co-digestion of sewage sludge, food waste and yard waste: Synergistic enhancement on process stability and biogas production

The Science of The Total Environment ◽

10.1016/j.scitotenv.2019.135429 ◽

2020 ◽

Vol 704 ◽

pp. 135429 ◽

Cited By ~ 14

Author(s):

Lan Mu ◽

Lei Zhang ◽

Kongyun Zhu ◽

Jiao Ma ◽

Muhammad Ifran ◽

...

Keyword(s):

Sewage Sludge ◽

Food Waste ◽

Biogas Production ◽

Process Stability ◽

Yard Waste ◽

Synergistic Enhancement

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Rethinking Elective Cataract Surgery Diagnostics, Assessments, and Tools after the COVID-19 Pandemic Experience and Beyond: Insights from the EUROCOVCAT Group

Diagnostics ◽

10.3390/diagnostics10121035 ◽

2020 ◽

Vol 10 (12) ◽

pp. 1035

Author(s):

Daniele Tognetto ◽

Antoine P. Brézin ◽

Arthur B. Cummings ◽

Boris E. Malyugin ◽

Ozlem Evren Kemer ◽

...

Keyword(s):

Cataract Surgery ◽

Negative Impact ◽

Waiting Times ◽

The Elderly ◽

Recovery Phase ◽

Diagnostic Tools ◽

Special Focus ◽

Critical Issues ◽

Precautionary Measures ◽

The Impact

The progressive deterioration of the visual function in patients on waiting lists for cataract surgery has a negative impact on their quality of life, especially in the elderly population. Patient waiting times for cataract surgeries in many healthcare settings have increased recently due to the prolonged stop or slowdown of elective cataract surgery as a result of coronavirus disease 19 (COVID-19). The aim of this review is to highlight the impact of such a “de-prioritization” of cataract surgery and to summarize some critical issues and useful hints on how to reorganize cataract pathways, with a special focus on perioperative diagnostic tools during the recovery phase and beyond. The experiences of a group of surgeons originating from nine different countries, named the European COVID-19 Cataract Group (EUROCOVCAT), have been combined with the literature and recommendations from scientific ophthalmic societies and healthcare institutions. Key considerations for elective cataract surgery should include the reduction of the number of unnecessary visits and examinations, adoption of precautionary measures, and implementation of telemedicine instruments. New strategies should be adopted to provide an adequate level of assistance and to guarantee safety conditions. Flexibility will be the watchword and regular updates would be necessary following scientific insights and the development of the pandemic.

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MBR-Assisted VFAs Production from Excess Sewage Sludge and Food Waste Slurry for Sustainable Wastewater Treatment

Applied Sciences ◽

10.3390/app10082921 ◽

2020 ◽

Vol 10 (8) ◽

pp. 2921 ◽

Cited By ~ 3

Author(s):

Mohsen Parchami ◽

Steven Wainaina ◽

Amir Mahboubi ◽

David I’Ons ◽

Mohammad J. Taherzadeh

Keyword(s):

Wastewater Treatment ◽

Sewage Sludge ◽

Food Waste ◽

Volatile Fatty Acids ◽

Wastewater Treatment Plants ◽

Biogas Production ◽

Economic Assessment ◽

Ph Control ◽

Daily Basis ◽

Solids Concentration

The significant amount of excess sewage sludge (ESS) generated on a daily basis by wastewater treatment plants (WWTPs) is mainly subjected to biogas production, as for other organic waste streams such as food waste slurry (FWS). However, these organic wastes can be further valorized by production of volatile fatty acids (VFAs) that have various applications such as the application as an external carbon source for the denitrification stage at a WWTP. In this study, an immersed membrane bioreactor set-up was proposed for the stable production and in situ recovery of clarified VFAs from ESS and FWS. The VFAs yields from ESS and FWS reached 0.38 and 0.34 gVFA/gVSadded, respectively, during a three-month operation period without pH control. The average flux during the stable VFAs production phase with the ESS was 5.53 L/m2/h while 16.18 L/m2/h was attained with FWS. Moreover, minimal flux deterioration was observed even during operation at maximum suspended solids concentration of 32 g/L, implying that the membrane bioreactors could potentially guarantee the required volumetric productivities. In addition, the techno-economic assessment of retrofitting the membrane-assisted VFAs production process in an actual WWTP estimated savings of up to 140 €/h for replacing 300 kg/h of methanol with VFAs.

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