Analysis of the Long-Term Mass Balance and Efficiency of Waste Recovery in a Municipal Waste Biodrying Plant

The aim of this study was to determine the role of an installation based on biodrying of municipal waste in a Circular Economy by taking into account the quantitative and qualitative changes in its selectively collected waste stream. As a case study, the Mechanical-Biological municipal waste treatment installation in Olsztyn, Poland, was selected, which is equipped with a separate section for valorizing the selectively collected waste stream. The scope of the work included a complete mass balance of the waste treatment plant, an assessment of the technological efficiency of the municipal waste biodrying installation, and determination of the changes in the main waste from 2016 to 2020. This paper proposes an empirical method for estimating process loss during biodrying and provides many technological results. The average process loss was 23.47%, and on average, 88.9% of the waste produced by biodrying consisted of the Refuse-Derived Fuel fraction. The recovery of commercial assortments from selectively collected waste increased from 84.82% in 2016 to 89.26% in 2020. Considering the current morphology of municipal waste in this region, the maximum share of waste subjected to material and organic recycling processes in the analyzed region could be increased to around 60%, which indicates that Circular Economy targets can be achieved. This work should provide a compendium of information for countries implementing a Circular Economy.

Renewing Materials: 3D Printing and Distributed Recycling Disrupting Samoa's Plastic Waste Stream

<p>This research addresses the serious issue of plastic waste in the Pacific. Using Samoa as a case study, we hypothesise that distributed recycling combined with 3D printing offers an opportunity to re-purpose and add new value to this difficult waste stream. It is also an opportunity to engage diverse local communities in Samoa by combining notions of participatory design, maker-spaces and ‘wikis’ of parts with traditional Samoan social concepts such as ‘Fa’a Samoa’, or ‘the Samoan way’ and sense of community. The project seeks to explore creative and innovative solutions to re-purposing plastic waste via a range of design research methods. Field work in Samoa has established the scope of the issue through interviews with different stakeholders such as Government, waste management businesses, the arts and crafts community and education. The field work has also helped identify potential product areas and collaborative partners. The different types of plastic in the waste stream have been identified and material experiments such as plastic shredding and filament extrusion are underway using low cost open source processing equipment to transform plastic waste into usable 3D printing filament. From this filament, potential 3D printed end products are explored through a hands-on researching by making process. The experiments inform the design of workable, economically viable, socially empowering and sustainable scenarios for re-purposing and up-cycling plastic waste; printed in the form of useful and culturally meaningful 3D printed objects, artifacts and products.Applications range from creating greater awareness of the issue by way of tourism and the Samoan notion of ‘mea alofa’ or ‘gifting’, through to functional utensils and parts. It is an opportunity to expand Samoa’s traditional forms of craft into new self-sustaining communities, maker-spaces and small scale local industries. The outputs of the initial project are intended to provoke discussion and invite participation in the implementation of these different scenarios of production.</p>

Renewing Materials: 3D Printing and Distributed Recycling Disrupting Samoa's Plastic Waste Stream

<p>This research addresses the serious issue of plastic waste in the Pacific. Using Samoa as a case study, we hypothesise that distributed recycling combined with 3D printing offers an opportunity to re-purpose and add new value to this difficult waste stream. It is also an opportunity to engage diverse local communities in Samoa by combining notions of participatory design, maker-spaces and ‘wikis’ of parts with traditional Samoan social concepts such as ‘Fa’a Samoa’, or ‘the Samoan way’ and sense of community. The project seeks to explore creative and innovative solutions to re-purposing plastic waste via a range of design research methods. Field work in Samoa has established the scope of the issue through interviews with different stakeholders such as Government, waste management businesses, the arts and crafts community and education. The field work has also helped identify potential product areas and collaborative partners. The different types of plastic in the waste stream have been identified and material experiments such as plastic shredding and filament extrusion are underway using low cost open source processing equipment to transform plastic waste into usable 3D printing filament. From this filament, potential 3D printed end products are explored through a hands-on researching by making process. The experiments inform the design of workable, economically viable, socially empowering and sustainable scenarios for re-purposing and up-cycling plastic waste; printed in the form of useful and culturally meaningful 3D printed objects, artifacts and products.Applications range from creating greater awareness of the issue by way of tourism and the Samoan notion of ‘mea alofa’ or ‘gifting’, through to functional utensils and parts. It is an opportunity to expand Samoa’s traditional forms of craft into new self-sustaining communities, maker-spaces and small scale local industries. The outputs of the initial project are intended to provoke discussion and invite participation in the implementation of these different scenarios of production.</p>

Research underpinning the design of an optical sorting plant

In the sorting plant examined during the research, the sorting of the selectively collected mixed packaging waste is done by hand. Studies were performed on the quantitative changes of the waste stream entering and leaving the sorting plant, the composition properties according to the particle size, and lastly the number of pickings. The amount of incoming waste has increased linearly over the years. The sizes preferred by the optical separators were the guideline during the measurements. Sixty percentage of all incoming waste falls in the ideal range of 70–350 mm, 20% in the range of <70 mm and 20% in the range of >350 mm. Because there are significant differences in composition and quantities as the seasons and months alternate, these results provide important information for engineers designing a mechanized technology.

Forward Osmosis: An Approach to Reclaim Dairy Waste Stream Whey

Recognizing the issues with conventional water resources and stricter wastewater effluent disposal standards, the treatment and recovery from wastewater are gaining impetus. The dairy industry consumes a substantial amount of water and generates a massive quantity of wastewater annually. Whey, which is about 94% water, is a waste stream produced in the dairy industry during the manufacture of cheese, paneer, yogurt, etc. Although various wastewater treatment technologies are available in the market, membrane technologies are considered the most advanced and reliable ones, but they are expensive. In recent years, Forward Osmosis (FO) is looked upon as a potential alternative to these costly and energy intensive pressure driven membrane processes. FO works on the principle of natural osmotic pressure where energy is just required to lift the solutions. The present lab-scale study investigates the partial reclamation of water from whey using FO technology. The Continuous Single Pass (CSP) and Recirculation mode (RC) study is conducted using high osmotic pressure (π = 375 bar at 298K) saturated aqueous(aq.) NaCl as the draw solution. The aq. NaCl solution is a potential brine stream in the dairy industry and finds applications in the manufacture of paneer, butter, cheese and ice cream eliminating the need for draw regeneration. The back diffusion study of the Hollow Fibre Forward Osmosis (HFFO) membrane revealed about 0.82% back diffusion of solute. The maximum water recovery of ~ 56% is achieved in CSP mode while 57.6% is achieved for RC mode with Feed/Draw ratio of 4.5:1. For F/D of 10:1, the maximum permeate flux of ~ 8.7 kg m− 2 h− 1 is observed for the CSP mode of operation for 10 minutes of study. Thus, FO is an efficient membrane technique that eliminates the need for draw regeneration and can be applied in the dairy industry.

Segregation of Plastic Waste from Solid Waste Stream: Bangladesh Perspective

Solid waste is an inevitable by-product of human beings, animals and also of industrial-commercial activities. Obviously solid waste creates a greater problem to the environment, if it is not properly managed. Bangladesh being a heavily populated country needs to pay adequate attention to waste management. Waste generation in Bangladesh is increasing because of rapid urbanization and economic development of the country. At present, total solid waste generation in Bangladesh is around 27000 tons/day and in the four important city corporations is about 13,332 tons. Particularly in Dhaka city, it is around 7500 tons/day. This amount is likely to reach about 47000 tons per day in entire Bangladesh and 15000 tons per day for Dhaka city alone by 2030. At present, landfilling is the only method for disposal of heterogeneous waste stream and there are three landfills in Dhaka City. Most of these landfill sites are in open dumps polluting land, water and air. Development of any new landfill site is near to impossible due to land scarcity and increasing of land prices especially in Dhaka City. Improperly disposed waste is posing serious health implications to the people and it may transmit various diseases especially by non-degradable wastes like polythene. Rather, a proper Segregation system to recover of resource from plastic wastes can play a very important role in mitigating the difficulties of solid waste that can act as a raw material for product design in Bangladesh too. Therefore, a comprehensive study report followed by a model of plastic waste segregation system for Bangladesh has been highlighted in the paper.

Study of Novel Separation Technique 'Pervaporation' for Separation of Acetronitrile and Tetrahydrofuran from waste Stream

Pervaporation is a very effective membrane process for the separation of liquid mixtures. Due to its economics, efficiency and simplicity, it can easily be integrated into the distillation and rectification processes and, depending on the specific operating parameters, even partially replace them. Pervaporation technology can effectively recovery acetonitrile from the waste stream and separate a tetrahydrofuran (THF) solvent-water waste stream. Pervaporation technique was used for the mixture of close boiling point and to break the azeotrope in the most economical way. The combination of Distillation columns and pervaporation unit were used for recovery of acetoniritle which was not TDS process and was economically feasible for larger stream. This technique used is economical and energy efficient for the separation.