Week 02 (WASTE): Five Sustainability Research of the week

The theme for this week’s sustainability research is WASTE

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Research in Details

Research #1

Complex odor control based on ozonation/GAC advanced treatment: optimization and application in one full-scale water treatment plant

Highlights

  • Concentration of odorants in low OTC must be achieved to resolve odor problem in drinking water

  • 2-MIB and BCIE have low reactivity towards ozonation directly

  • Combination of pre-ozonation with coagulation, sedimentation and sand filtration with post-ozonation filtered using GAC filter process remove odor in drinking water

Authors: Ping Xia, Shuangyi Zhang, Jianwei Yu, Hui Ye, Dong Zhang, Lei Jiang, Zheng Wang & Daqiang Yin

Date of publication: 25 March, 2020

Summary

Taste and odor problem in drinking water is one major concern for consumers and water supply. Exploring the odor characteristics and the major odor causing compounds in the source water is the base for odor control in drinking water treatment plant (WTP). In this study, focusing on a newly constructed reservoir with Huangpu River as the source water, the occurrence of typical odorants and their variations were first identified. Correspondingly, the removal behavior in an ozone/GAC advanced treatment process was investigated. To resolve the odor problem in the drinking water, the concentrations of the odorants at less than their OTCs need to be achieved. As 2-MIB and BCIE have low reactivity towards direct ozonation, a subsequent GAC is needed with a moderate dosage of post-ozonation (1 mg L−1). Thus, for the odor problem in the source water, the suggested operation is: 1 mg L−1 of pre-ozonation in combination with coagulation, sedimentation, and sand filtration, followed by a 1 mg L−1 dosage of post-ozonation and finished by a GAC process

Research #2

Food waste composting - Is it really so simple as stated in scientific literature? – A case study

Highlights

  • There are gaps in the current knowledge of the food waste composting process.

  • Food waste in electric composter is reduced and hygienized.

  • Composting process in electric composter does not work well.

  •   The value of pH, C/N ratio and phytotoxicity test of final product is obtained.

  • The final product does not exhibit properties for mature compost.

Authors: Stanislava Voberkova, Alzbeta Maxianova, Nikola schlosserova, Dana Adamcova, Martina Vrsanska, Lukas Richtera, Milica Gagic, Jan Zloch, Magdalena Daria Vaverkova

Date of publication:  24 March, 2020

Summary

Food waste has recently gained much worldwide interest due to its influence on the environment, economy and society. Gathering and recycling of food waste is the essential issue in the waste management and the interest in processing food waste arises mainly out of influence of the processes of food putrefaction on the environment. Composting of food waste encounters a number of technical challenges, arising weak physical structure of food waste with weak porosity, high content of water, low carbon-to-nitrogen relation and fast hydrolysis and accumulation of organic acids during composting. Therefore, the aim of this study was to investigate the challenges facing installations intended for food waste composting, with the purpose to their optimization with use of appropriate additives. Physico-chemical, biochemical characteristics and phytotoxicity of the produced compost has been measured. Two additives (20% biochar and 20% sawdust) were chosen from experimental variants I-XII containing different additives (biochar, Devonian sand, sawdust) in diverse concentration. The use of selected additives seems to slightly increase potential of hydrogen value and carbon-to-nitrogen ratio, while decreasing electrical conductivity in comparison with control sample. The results obtained also show that the addition of biochar leads to an increase dehydrogenase, phosphatase and arylsulphatase activities and addition of sawdust has a positive effect on beta-D-glucosidase, protease, phosphatase and arylsulphatase activities. The phytotoxicity test shows that the compost made of food waste (control sample) and with addition of biochar is toxic to plants. By contrast, the addition of sawdust shows that the compost was not phytotoxic. In conclusion, the addition of additives does not provide unambiguous results in terms of the quality of the final product in all monitored parameters. Therefore, we can state that food waste was reduced and hygienized, and that the final product does not meet conditions for mature compost.

Keywords: Food waste, Organic recycling, Additives, Enzymatic activities, Phytotoxicity, Sustainability

Research #3

Passivation of lead and cadmium and increase of the nutrient content during sewage sludge composting by phosphate amendments

Highlights:

  • Both phosphate rock and monopotassium phosphate passivated Cd and Pb.

  •   Changes in Phosphate speciation were observed by XANES spectroscopy.

  • Formation of phosphate precipitates was determined by XRD spectral patterns. 

  • Phosphate promoted organic matter degradation during composting.

 Authors: Guodi Zheng, Xiankai Wang, Tongbin Chen, Jun Yang, Junxung Yang, Junwan Liu, Xiaoxiao Shi

Date of publication: March 23, 2020

Summary

As an efficient and cost-effective biological treatment method for sewage sludge, composting has been widely used worldwide. To passivate heavy metals and enhance the nutrient content in compost, in the present study, phosphate rock, calcium magnesium phosphate, and monopotassium phosphate were added to the composting substrate. According to the Community Bureau of Reference sequential extraction procedure, phosphate rock and monopotassium phosphate amendments exhibit a good passivation effect on Cd and Pb. The X-ray diffraction patterns proved the formation of Pb3(PO4)2 and Cd5(PO4)2SiO4 crystals, and X-ray absorption near-edge structure spectroscopy illustrated the change in P speciation after phosphate amendment. Furthermore, phosphate amendment increased the contents of total P and available P, and it reduced the loss of N during sewage sludge composting. The germination index showed that the target phosphate amendments in sewage sludge compost had no negative effects on seed germination, and this method has great potential to be used as a soil amendment.

Keywords: Sewage, sludge, Composting, Heavy metals, Phosphorus speciation, X-ray absorption near-edge structure

Research #4

Public views and attitudes about municipal waste management: Empirical evidence from Athens, Greece

Highlights:

  • Participation of the public and unity are the major elements to bring about waste management programs

  • The waste management’s programs include recycling, composting, and green centers

  • Recycling was practiced by majority of the Athens

  • Proper awareness can help foster the waste management program

Authors: Efi Drimmili, Ruth H erreror-martin, Juain Suardiaz-muro, Efithimios Zervas

Date of publication: March 23, 2020

Summary

One of the major problems of modern cities is waste management. Cooperation and active public participation are key elements in the effective implementation of waste management programs. The purpose of this work is to investigate the views and attitudes of Athens residents towards recycling, composting and the operation of green centers, which are the key elements of solid waste management as it follows from the recently updated National Waste Management Plan. A structured questionnaire was designed and addressed to the residents of Athens. According to the main findings, half of the respondents involved in recycling, and the majority of the respondents are willing to participate in future composting programs and have a positive opinion about the operation of green centers. The main obstacle for their further participation is their hesitation regarding the proper operation of the programs (recycling, composting, green centers). There is a need to build up the trust between citizens and the state. Active public involvement is required to successfully implement municipal solid waste strategies during all the phases (planning, siting and operation) in order to ensure public acceptance. In addition, targeted information and awareness campaigns can also contribute to this aim.

Keywords: Public view, attitude, municipal waste management, Athens, recycling, composting, National Waste Management Plan


Research #5

Community-scale composting for food waste: A life-cycle assessment-supported case study

Highlights

  • A community-scale organic waste composting system is presented.

  • It takes 7 months to produce compost from food waste, with leaves as bulking agent.

  • The compost yield is 30% and its quality meets the organic fertiliser standards.

  • Socio-cultural, economic, environmental and technical barriers were evaluated.

  • This system could be replicated and scaled up easily for widespread applications.

Authors: Zi Xiang Keng, Siewhui Chong, Chee Guan Ng, Nur Izzati Ridzuan, Svenja Hanzon, Guan-ting pan, Phei Li Lan, Chritina Vimala, Supramaniam, Aijit Singh, Chiew Foam Chin, Hon Loong Lam

Date of publication: 21 March 2020

Summary

Community-scale composting, which can be conducted by the local council or a waste management company, is an effective starting point to divert food waste from landfill, especially for developing countries. This paper successfully demonstrates the feasibility of a community-scale food waste composting system, using the University of Nottingham Malaysia as the case study. The method selected is open-air static pile, using food waste as the substrate and leaf-litter as the bulking agent. The composting model presented in this study is also applicable to other organic wastes. The two feedstocks are mixed at a food waste-to-leaves weight ratio of 4: 1 to result in an initial moisture level of 63% and carbon-to-nitrogen ratio of 27. The composting process can be completed in 7 months, yielding about 30 wt % (on dry basis) of compost from the total organic feedstock. The finished compost is shown to meet Malaysia's organic fertiliser standard, thus demonstrating the feasibility of this low-cost technology. Economic analysis showed that substituting chemical fertilisers with the organic compost produced in-house is a viable option, and that for Malaysia, the composting system would be able to self-sustain financially only when the landfilling cost is increased 2.3 times. The life-cycle assessment showed that using composting to replace landfill for food waste, as well as substituting chemical fertilisers with the organic compost produced, can greatly reduce the environmental impacts, especially on global warming, ecotoxicity, eutrophication and fossil fuel depletion. In order to promote the widespread application of composting for organic wastes, multi-actor partnerships are essential to link governments, organisations and households in working toward a circular economy.

Keywords: Organic waste, Food waste, Composting, Life cycle, Circular economy, Feasibility

Week 01 (CLIMATE): Five Sustainability Research of the Week

The theme for this week’s sustainability research is CLIMATE

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Research in Details:

Research #1

Analysis of the port sustainability parameters through Bayesian networks

Highlights

  • Ports are needed for a sustainable movement of goods

  • The methods to be used for the application of the ports have shortcomings

  • The Bayelsian Network is used to determine the relationship between variables graphically to measure their sustainability

  • The Bayelsian Network enable the port sector to rouse from the state of inactivity

Authors: Beatriz Molina Serranoa, Nicoletta González-Cancelasa, Francisco Soler-Flores

Date of publication: 14 March, 2020

Summary

Transport sector is an important component of the economy because it impacts on the development and well-being of population. However, it generates environmental needs and negative impacts, such as greenhouse gases emissions. A good transportation planning and management makes possible to reduce them.

In this context, ports are called upon to contribute to a more sustainable mobility of goods. The number of variables to be considered in order to carry out the decision making and to make the management of the ports sustainable is very large.

However, the strong methodological limitation existing has not allowed the application of this concept, still being a critical aspect.

The Bayesian networks are one of the possible methodologies to apply. These networks, allow to obtain the relations between variables graphically in order to determine a posteriori values that quantify their sustainability. Bayesian networks allow the relationships between the variables of port planning and operation related to sustainability to be obtained. These relationships, and especially their relationship through influence diagrams that categorize the role of the port sector as a revitalizer of port activity increases.



Research #2

Social and environmental analysis of food waste abatement via the peer-to-peer sharing economy

Highlights

  • Sharing economy can foster reduction of food wastage in an environmental way

  • Food exchange occurs mostly between users of the same income

  • Food insecurity and malnutrition affect the low , medium and the high income countries

Authors: Tamar Makov, Alon Shepon, Jonathan Krones, Clare Gupta & Marian Chertow

Date of publication: 10 March 2020

Summary

Reducing food waste is widely recognized as critical for improving resource efficiency and meeting the nutritional demand of a growing human population. Here we explore whether the sharing economy can provide meaningful assistance to reducing food waste in a relatively low-impact and environmentally-sound way. Analyzing 170,000 postings on a popular peer-to-peer food-sharing app, we find that over 19 months, 90t of food waste with an equivalent retail value of £0.7 million were collected by secondary consumers and diverted from disposal. An environmental analysis focused on Greater London reveals that these exchanges were responsible for avoiding emission of 87–156t of CO2eq. Our results indicate that most exchanges were among users associated with lower income yet higher levels of education. These findings, together with the high collection rates (60% on average) suggest that the sharing economy may offer powerful means for improving resource efficiency and reducing food waste.

Research #3

Assessment of riparian zone dynamics and its flood-related implications in Eleyele area of Ibadan, Nigeria

Highlights

  • The riparian zone increase the vulnerability level to flooding

  • The vulnerability of a riparian zone is analysed using remote sensing data sense

  • Flood vulnerability models were created according to the landcover type

  • The increase In the built up area over the period of the study show the most vulnerable zone to flood as at 2019

Authors: Oluwayemisi S. Olokeogun, Ayansina Ayanlade & Olusola O. Popoola

Date of publication: 10 March, 2020

Summary

This research focused on the assessment of riparian zone dynamics and its flood-related implications in the Eleyele area of Ibadan, Nigeria. The findings reveal the existence of land cover changes within RH and FA zones of the study area over a period of 20 years (1999 and 2019), in which the water body, grassland, and forest land cover class decreased while built-up area increased drastically. These changes are significantly human-induced. There is a significant level of structural change of the riparian zone which increases its vulnerability level to flooding.

This study aims at assessing how riparian zones have been altered through various land use activities and the implications of its capacity to mitigate flood. The study focused mainly on examining the land use/land cover changes within the riparian zone over a period of 20 years. The vulnerability of the riparian zone to flood were analyzed using remote sensing datasets. Flood vulnerability models were created based on the elevation and land cover type. A Euclidean distance (700 m) was created using the shuttle radar topographical mapping (SRTM) digital elevation model (DEM) of the lake and its riparian zone. The flood attenuation (150 m buffer) and riparian habitat (500 m) zones (areas) within the riparian zone of the lake were then created using the extracted lake boundary. Landsat 7 (for 1999) and 8 (for 2019) covering both zones were classified using the Maximum Likelihood Classification method. The results revealed that the built-up area increased from 2.04 to 4.54 km2 by 0.05 to 0.04 km2, 0.37 to 0.12 km2 and 1.84 to 1.82 km2 over the period of the study. The results further show that about 18.9% of built-up areas were within the very high vulnerability zone of flood as of the year 2019. The reping sediments and enhancing infiltration. The pattern of distribution of the land cover classes at different flood vulnerability levels within zones indicates that the more the alteration of both zones’ landscape, the more vulnerable they are to flood. The stuway concluded that there is a significant level of structural change of riparian zone which increases its vulnerability level to flooding.

Research #4

Feasible alternatives to green growth

Highlights

  • Climate change and increasing income inequality tends to affect standards if living

  • Dynamic macrosimulation model was developed to observe the long-term effects of green growth,policies for social equity and degrowth

  • The model was developed to manage a fair Low-carbon transition

  • Green growth policiesfir social equity and degrowth help in improving environmental performance by reducing emission of green house gas

Authors: Simone D’Alessandro, André Cieplinski, Tiziano Distefano & Kristofer Dittmer

Date of publication: 09 March 2020 

Summary

Climate change and increasing income inequality have emerged as twin threats to contemporary standards of living, peace and democracy. These two problems are usually tackled separately in the policy agenda. A new breed of radical proposals have been advanced to manage a fair low-carbon transition. In this spirit, we develop a dynamic macrosimulation model to investigate the long-term effects of three scenarios: green growth, policies for social equity, and degrowth. The green growth scenario, based on technological progress and environmental policies, achieves a significant reduction in greenhouse gas emissions at the cost of increasing income inequality and unemployment. The policies for social equity scenario adds direct labor market interventions that result in an environmental performance similar to green growth while improving social conditions at the cost of increasing public deficit. The degrowth scenario further adds a reduction in consumption and exports, and achieves a greater reduction in emissions and inequality with higher public deficit, despite the introduction of a wealth tax. We argue that new radical social policies can combine social prosperity and low-carbon emissions and are economically and politically feasible.

Research #5

Spatial and temporal drought incidence analysis in the northeastern highlands of Ethiopia

Highlights

  • The use of standardized precipitation index to present the spatio temporal drought risk event in the Northeast highlands of Ethiopia

  •   Highly complex and localized temporal and spatial pattern of drought risk events were discovered

  •   The frequency and magnitude of drought risk events were more strongly marked during rainy months

  • A complex spatial variations of drought risk events were observed between kiremt and belg

  • Documentation and assessment of drought risk events in relation to the zones livelihood is quite important for managing drought risk event

Author: Abebe Arega Mekonen, Arega Bazezew Berlie &Mehrete Belay Ferede 

Date of publication: 03 March 2020

Summary         

This study presented the spatiotemporal drought risk events in the northeastern highlands of Ethiopia using Standardized Precipitation Index, SPI. The results of the study confirm that highly complex and localized temporal and spatial patterns of drought risk events were detected. This helped to identify and characterize local droughts. The majority of 1–4- and 8-months timestep underwent severe and extreme (SPI ≤ − 1.50) drought events. However, the detected frequency and magnitude of drought risk events were more pronounced during the rainy months of the belg season. This study investigated the space-time drought incidence in the northeastern highlands of Ethiopia using monthly rainfall data. It also aims to predict drought events for 100 years. The Standardized Precipitation Index (SPI) was used to compute the drought severity classes of rainy months and seasons at 1-, 4- and 8-months timestep.

 The Mann-Kendall’s test and Sen’s slope estimator were used to analyze the trends of drought events and to determine the magnitude of change. Inverse Distance Weighted spatial analysis tool was used to illustrate the spatial patterns of the drought risk events.The study detected extreme severe droughts in the belg rainy months in March 2008 and April 1984. However, during the belg season, the year 1999 was the driest for the recorded periods. On the other hand, the extremely severe droughts were observed during the kiremt rainy months of July 1987 and 2015, August 1984, and September 2009. In general, 1984, 1987 and 2015 were the driest years recorded in the kiremt season. The study noted that the drought risk events of months in the belg season were threefold greater than that of the months in kiremt season under moderate drought intensity class. Equally, the drought risk events of months in kiremt season were threefold greater than that of the belg season under extreme drought intensity class. Complex spatial variations of drought risk events were also observed in 1-, 4- and 8-months timesteps. During the belg seasons, the southern half was subjected to more frequent drought risk events while the northern half experienced more frequent drought risk events during kiremt season. Almost the eastern half of the livelihood zones experienced high rate to the rainfed agricultural practices that have a great influence on the livelihoods of smallholder farmers. Hence, documentation and assessmentHighlightsfihood zones are essential for drought risk management, early warning responses, local-scale planning and food security management. Finally, the study recommended further research on additional indices of climatic variables such as evapotranspiration and soil water content.