Municipal Waste Management Strategy Review and Waste-to-Energy Potentials in New Zealand

Exposure to Hazardous Substances and Their Health Effects Among Residents Living Near Three Industrial Waste Incinerators in Korea

BACKGROUND

This study aimed to evaluate exposure to various hazardous substances emitted by incineration facilities and their likely effect on the health for residents of Bugi-myeon, Cheongju, Korea, which has three incineration facilities.

METHODS

Heavy metals, polycyclic aromatic hydrocarbons (PAHs), and dioxin concentrations in the air and soil of exposed and control areas were measured. Moreover, the exposure levels to harmful substances and its effects on health were investigated in 1,124 exposed and 232 control adults.

RESULTS

PAHs and dioxin concentrations in the air in the exposed area were significantly higher than in the control area. Urinary cadmium and PAHs metabolite concentrations were significantly higher in the exposed group than in the control group. The exposure group also had a higher prevalence of depression and self-reported allergic symptoms than the control group.

CONCLUSION

The possibility of residents in Bugi-myeon being exposed to hazardous substances at incineration facilities cannot be ruled out. To prevent them from further exposure to hazardous substances, it is necessary to prohibit the expansion of additional incineration facilities in this area and to implement continuous monitoring projects for residents.

Cooperative environmental governance in urban South Asia: implications for municipal waste management and waste-to-energy

This paper critically discusses the importance of cooperative environmental governance (CEG) for efficient waste management and waste-to-energy (WtE) generation in the context of growing urban South Asia. Focusing on Bangladesh, India and Pakistan experiences, the paper reveals that even though much progress has been done in the urbanisation in the selected countries, the process of waste management (mainly municipal solid waste) has not been effective due to low level of local inclusion. As a result, the WtE generation potential has not been realised to its fullest. In addition, it has been argued that institutional and social reforms are extremely important for strengthening the CEG, and it will eventually lead to effective and optimal WtE generation in the urban cities of the selected South Asian countries for green transition and urban sustainability. Finally, an integrated solid waste management framework has been formulated for policy implications in South Asia.

Municipal solid waste treatment for bioenergy and resource production: Potential technologies, techno-economic-environmental aspects and implications of membrane-based recovery

World estimated municipal solid waste generating at an alarming rate and its disposal is a severe concern of today's world. It is equivalent to 0.79 kg/d per person footprint and causing climate change; health hazards and other environmental issues which need attention on an urgent basis. Waste to energy (WTE) considers as an alternative renewable energy potential to recover energy from waste and reduce the global waste problems. WTE reduced the burden on fossil fuels for energy generation, waste volumes, environmental, and greenhouse gases emissions. This critical review aims to evaluate the source of solid waste generation and the possible routes of waste management such as biological landfill and thermal treatment (Incineration, pyrolysis, and gasification). Moreover, a comparative evaluation of different technologies was reviewed in terms of economic and environmental aspects along with their limitations and advantages. Critical literature revealed that gasification seemed to be the efficient route and environmentally sustainable. In addition, a framework for the gasification process, gasifier types, and selection of gasifiers for MSW was presented. The country-wise solutions recommendation was proposed for solid waste management with the least impact on the environment. Furthermore, key issues and potential perspectives that require urgent attention to facilitate global penetration are highlighted. Finally, practical implications of membrane and comparison membrane-based separation technology with other conventional technologies to recover bioenergy and resources were discussed. It is expected that this study will lead towards practical solution for future advancement in terms of economic and environmental concerns, and also provide economic feasibility and practical implications for global penetration.

Rice Straw Utilisation for Bioenergy Production: A Brief Overview

Unsustainable rice straw management causes environmental impacts; hence, utilisation of rice straw for bioenergy is a promising strategy for sustainable rice straw management. Although rice straw has a high potential for bioenergy generation, the whole production cycle and application may cause environmental damage that is not fully understood. Hence, environmental performance studies are required to determine the most effective rice straw utilisation options. A comprehensive approach, such as life-cycle assessment (LCA), can give comprehensive information on the possible environmental effects of rice straw utilisation for bioenergy. Therefore, this study briefly overviews the LCA of rice straw utilisation for bioenergy production. It is found that utilisation of rice straw for bioenergy could reduce global warming potential compared to energy production from fossil fuels. However, it is suggested that other impact categories in LCA be evaluated in the bioenergy production from rice straw research to determine the overall sustainability of the production.

Risk Analysis of Public–Private Partnership Waste-to-Energy Incineration Projects from the Perspective of Rural Revitalization

In China, more and more waste-to-energy (WTE) incineration plants are being delivered through public–private partnership (PPP) schemes in rural areas, which are focused on rural revitalization. These can not only deal with the ever-increasing solid waste but also provide renewable energy and thus benefit local societies. However, they usually endure a lot of risks due to long concession periods and complex contractual relationships. This research investigates the risk management of PPP WTE incineration projects from the perspective of rural revitalization. First, a preliminary list of 36 risks was derived based on a literature review. Second, a focused group discussion with eight experts was held to obtain the final list of 36 risk factors, taking into account rural revitalization. Third, a structured questionnaire survey was conducted to consult the risk frequency and risk severity. A total of 100 valid questionaries were collected. Finally, risk analysis and discussion were provided on the basis of the survey. The top 10 risks are rural appearance, payment risk, local employment, local economic development, local government succession, operation cost overrun, waste supply, construction cost overrun, revenue risk and price change risk. It indicates that (1) PPP WTE incineration projects can effectively promote rural development; (2) government authorities play a significant role in the sustainable development of PPP WTE incineration projects; and (3) the risk preference of rural PPP WTE incineration projects is social, economic and environmental risks.

COVID-19 and municipal solid waste (MSW) management: a review

Municipal solid waste (MSW) represents an inevitable by-product of human activity and a major crisis for communities across the globe. In recent times, the recycling of MSW has drawn attention as the process can add value through resources from the recovered waste materials and facilitates the process of circular economy. However, during the unprecedented coronavirus (COVID-19) outbreak, the risk of infection with the highly contagious virus has proven detrimental to the continuation of MSW as a valuable resource. The volume of waste, especially household waste, is higher; face masks, PPE (personal protective equipment), and hazardous materials such as batteries and empty chlorine bottles are examples of extra waste that have arisen during the pandemic. Various countries have set up initiatives for MSW management, including safety measurements for employees in the MSW management sector. The use of disinfectant prior to sorting waste, as well as storing waste for 9 days, may help to inactivate the COVID-19 virus, ensuring an appropriate safety level for MSW management. This work aimed at studying different MSW management strategies, specific challenges, and possible solutions for better understanding for those involved in waste management, in addition to providing a possible management strategy during and post-COVID-19 pandemic.

Municipal solid waste recycling: Impacts on energy savings and air pollution

In recent years, recycling of municipal solid waste (MSW) has been recognized as one of the most efficient methods of waste management in terms of environmental benefits. This study investigates the energy savings and other environmental benefits of recycling of dry MSW collected in Shiraz, Iran (2018). The impact of different recycling rates (current = 15%, desirable = 50%, ideal = 80%) on environmental benefits and energy savings were assessed. The annual quantity of recycled components were defined as glass (735 tons), plastic carrier bags (555 tons), cardboard (3,874 tons), paper (3,806 tons), disposable plastic containers (287 tons), other types of metals (785 tons), disposable metallic containers (aluminum) (171 tons), other types of plastics (812 tons) and polyethylene terephthalate (PET) (887 tons). The results confirmed that recycling of paper and glass in three different scenarios resulted in a reduction of 1.01, 2.14, and 3.43 million tons of air pollutant emissions, respectively. By improving the recycling rates from 15 to 80%, overall energy savings can improve by between a factor of 3.5 to 5.5. Also, a reduction of approximately 2-3.5% in air pollutant emissions can be achieved by upgrading the current recycling program (15% recycling rate) to favorable and ideal conditions.Implications: In recent years, recycling of municipal solid waste (MSW) has been recognized as one of the most efficient methods of waste management in terms of environmental benefits. This study investigates the energy savings and other environmental benefits of recycling of dry MSW collected in Shiraz, Iran (2018). According to available data, there has been little effort for recycling in developing countries, and waste landfilling is recognized as the most favorable option in MSW management. The aim of this study was to characterize MSW components in Shiraz, Iran, and to quantify the environmental benefits and energy savings as result of paper, glass, and aluminum recycling. This work is novel in that there are no reports to our knowledge of the environmental benefits and energy savings resulting from different recycling scenarios including current (15%), desirable (50%), and ideal (80%) recycling for aluminum, paper, and glass. The results of this work have broad implications both for other regions owing to the pervasiveness of recycling facilities and also for developing countries that can strive towards the infrastructure needed to reach improved recycling scenarios.

Circular Economy in Poland: Profitability Analysis for Two Methods of Waste Processing in Small Municipalities

The problem of diminishing resources on our plant is now getting due attention from the governments as well as scientists around the world. The transition from a linear economy to a circular economy (CE) is now among the top priorities. This article discusses the implementation of the circular economy paradigm in Poland through the analysis of the existing and planned mechanisms, and actions taken by the Polish government which can be replicated by other young European countries. Further, the article discusses the direction of change and projected measures planned by the Polish government to improve the quality of municipal solid waste management. In this context, profitability analysis is carried out for two methods of waste processing (incineration and torrefaction) intended for small municipalities and settlements in which district heating and trading of generated electricity are not feasible. The results of the analysis shows that torrefaction is clearly a more desirable waste processing option as a step towards the implementation of CE for civic society in the urban context, as well as profitability, in comparison to incineration. The analysis accounts for several scenarios before the lockdown caused due to the COVID-19 pandemic and after it was lifted.

Mixed-integer non-linear programming (MINLP) multi-period multi-objective optimization of advanced power plant through gasification of municipal solid waste (MSW)

Multi-objective optimization is one of the most effective tools for the decision support system. This study aims to optimize the gasification of municipal solid waste (MSW) for advanced power plant. MSW gasifier is simulated using Aspen Plus v11 to produce syngas, to be fed into power generation technologies. Four power generation technologies are selected, solid oxide fuel cell, gas turbine, gas engine, and steam turbine. Mixed-integer non-linear programming (MINLP) multi-objective optimization is developed to provide an optimal solution for minimum levelized cost of electricity (LCOE) and minimum CO2eq emissions. The optimization is conducted with a ε-constraint method using GAMS through time periods of 2020–2050. Decision variables include gasifier temperature, steam to carbon ratio, and power generation technologies. The optimization result demonstrates that the lower steam to carbon ratio gives lower LCOE and higher CO2eq emissions, and temperature variation gives no significant impact on LCOE and as it increases, CO2eq emission is reduced. It demonstrates that a gas turbine is the best option for generating electricity from 2020 to 2040 and beyond 2040 SOFC is the best option.

Energy Utilization of Algae Biomass Waste Enteromorpha Resulting in Green Tide in China: Pyrolysis Kinetic Parameters Estimation Based on Shuffled Complex Evolution

Enteromorpha is a species of algae biomass that is spread widely and has resulted in green tides in China in recent years. It was urgent to explore an appropriate method for taking advantage of the ocean waste as an energy supply in the current sustainable development. Pyrolysis, as the first step of thermochemical conversion in energy utilization, was given attention in order to study its behavior based on thermogravimetric experiments over a wide heating-rate range from 5 to 60 K/min. The whole pyrolysis process was divided into three stages: water evaporation, the main components decomposition, and carbonate decomposition. To estimate the detailed kinetic parameters (activation energy, the pre-exponential factor, and reaction order etc.), the Kissinger method was used to establish the original kinetic parameters at different stages and provide the parameter search range for the next heuristic algorithm, and then the Shuffled Complex Evolution optimization algorithm was coupled and first applied to the algae biomass pyrolysis. Eventually, the predicted results of mass loss rate based on the optimized kinetic parameters agreed well with the thermogravimetric experimental data, with the R2 value being up to 0.92 for all the heating rates.

Assessment of Municipal Solid Waste Generation in Universiti Putra Malaysia and Its Potential for Green Energy Production

The global waste generation keeps increasing over the years and it requires innovative solutions to minimize its impacts on environmental quality and public health. A strategic plan must be ascertained to overcome the future challenges of Municipal solid waste (MSW) locally and globally. Universiti Putra Malaysia (UPM) coined an initiative to demonstrate a showcase pilot plant for green energy production from MSW. The data was obtained from the survey and actual sampling within the UPM compound shows that UPM has generated 5.0–7.0 t/d of MSW generated consist of 30–35% organic fraction. Restaurants are the main source of the organic fraction. Upon separation, the organic fractions were digested into biogas. At a maximum conversion of the organic fraction, 715 kWh of electricity might be generated from the 2.2 t/d of organic waste generated in UPM. In this study, organic components from UPM were proposed to be subsequently used as a substrate via anaerobic digestion to produce green energy in the form of electricity or flammable fuels.

Composting of municipal solid waste by different methods improved the growth of vegetables and reduced the health risks of cadmium and lead

Reutilization of putrescible municipal solid wastes (MSW) in agriculture can provide valuable plant nutrients. However, it may pose serious noncarcinogenic health risks for a human when contaminants, especially the heavy metals in MSW, end up in plants through the waste-soil-plant continuum. This study examined the effects of composting methods viz. aerobically (AC), anaerobically (ANC), and aerobic-anaerobically (AANC) composted MSW material on (i) fertilizer value: vegetable yield, nitrogen (N) mineralization, and apparent N recovery (ANR); and (ii) associated health risks: selected heavy metal concentration, daily intake of metals (DIM), health risk index (HRI), hazard index (HI), and target hazard quotient (THQ) when applied to a loamy soil. All the aforementioned compost materials were incorporated into the sandy loam soil filled in pots and carrot and spinach were cultivated for 85 and 90 days, respectively. After soil application, between 51 and 56% of the applied organic N was mineralized from ANC material, while the values in case of AC and AANC were 26-31% and 34-40%, respectively. Consequently, dry matter yield and vegetable N uptake from composts were in the order ANC > AANC > AC (P < 0.05). Further, vegetable ANR was the highest from ANC (56 and 56%) than AANC (42 and 45%), and AC (30 and 33%) for spinach and carrot, respectively (P < 0.05). Interestingly, plant uptake of lead and cadmium was lowest from ANC as compared to AC or AANC (P < 0.05), irrespective of the vegetable type. Consequently, DIM, HRI, and THQ for these metals were substantially lower in the former as compared to the latter compost materials. Further, HI from ANC material was 50% lower over the unfertilized control indicating the absence of noncarcinogenic human health risks via vegetable intake. This all indicates that from viewpoint of sustainable waste recycling in agriculture, anaerobic composting is superior to the other composting methods.

Waste Fuel Combustion: Dynamic Modeling and Control

The focus of this study is to present the adherent transients that accompany the combustion of waste derived fuels. This is accomplished, in large, by developing a dynamic model of the process, which can then be used for control purposes. Traditional control measures typically applied in the heat and power industry, i.e., PI (proportional-integral) controllers, might not be robust enough to handle the the accompanied transients associated with new fuels. Therefore, model predictive control is introduced as a means to achieve better combustion stability under transient conditions. The transient behavior of refuse derived fuel is addressed by developing a dynamic modeling library. Within the library, there are two models. The first is for assessing the performance of the heat exchangers to provide operational assistance for maintenance scheduling. The second model is of a circulating fluidized bed block, which includes combustion and steam (thermal) networks. The library has been validated using data from a 160 MW industrial installation located in Västerås, Sweden. The model can predict, with satisfactory accuracy, the boiler bed and riser temperatures, live steam temperature, and boiler load. This has been achieved by using process sensors for the feed-in streams. Based on this model three different control schemes are presented: a PI control scheme, model predictive control with feedforward, and model predictive control without feedforward. The model predictive control with feedforward has proven to give the best performance as it can maintain stable temperature profiles throughout the process when a measured disturbance is initiated. Furthermore, the implemented control incorporates the introduction of a soft-sensor for measuring the minimum fluidization velocity to maintain a consistent level of fluidization in the boiler for deterring bed material agglomeration.