Improving the composting process of a treatment facility via an Industry 4.0 monitoring and control solution: Performance and economic feasibility assessment.

The European Union has set ambitious targets for recycling and landfill disposal of urban waste by 2025 and 2035, respectively. Composting is considered one way to achieve these goals. This paper focuses on a case study of a compost industrial treatment facility to identify potential and economically feasible improvements for the process and the factory. Through a thorough analysis of the facility and its production process, a plant section suitable for reengineering intervention has been identified. A technological solution based on Industry 4.0 is proposed to facilitate the monitoring and control of the bio-oxidation phase. An economic and feasibility analysis of this investment has been carried out over a ten-year lifecycle, comparing it with the company's business plan. A hybrid simulation model has been implemented to simulate and evaluate the reengineered plant, revealing that the bio-oxidation phase can be shortened to an average of six days. This result suggests that the adoption of smart technologies to control these types of processes are desirable and should become a standard. The social and economic effects of this investment were also analyzed to evaluate how to reduce the fares keeping the investment still valuable for the community and the private entrepreneurs.

Combining biosolid and mineral sources of phosphorus and potassium in organomineral fertilizers influences the dynamics and efficiency of nutrient release.

Using urban residues to produce organomineral fertilizers (OMF) is an environmentally friendly strategy that can enhance soil fertility by adding organic matter and mineral nutrients. Herein we investigated the availability of N, P, and K, under organomineral fertilization in sandy soils. An incubation study was conducted using OMF formulated with biosolids as organic matrix and N source, rock phosphate, and potassium sulfate as P and K sources, respectively. Two forms of isolated N, P, and K sources (granulated and non-granulated), five N:P:K granulation proportions (1-2-0, 1-4-0, 1-0-2, 1-2-2, 1-2-4), and a control (unfertilized) were mixed with soil and assessed over a 112 days incubation period. Soil samples were collected at 0, 7, 14, 28, 56, and 112 days to quantify available soil concentrations of ammonium (N-NH4+), nitrate + nitrite (N-NO2- + N-NO3-), P, and K. The results showed that OMF formulated with NPK had better nitrogen efficiency indexes (NEI) than other formulations and did not induce N immobilization throughout the experiment. Regarding P and K efficiency, OMFs containing phosphorus and potassium increased the indexes compared to the single fertilizer sources. When comparing non-granulated potassium sulfate with granulated, the latter showed a steadier release due to the granulation process. In comparison with rock phosphate at the end of the experiment, the OMFs 1-2-0 and 1-4-2 had higher P available by 116 and 41%, respectively. Based on these results, OMFs have the potential to alter the dynamics of nutrient availability serving as a strategy for nutrient management in agriculture.

A Real-World Scenario of Citizens' Motivation and Engagement in Urban Waste Management Through a Mobile Application and Smart City Technology.

Circular bioeconomy is a key socioeconomic model for advancing the United Nations Global Sustainability Goals and promoting environmental and resource sustainability. However, circular bioeconomy concepts are unknown to most people and politicians worldwide who still have a fragmented picture of sustainability. Common perception of waste needs a cultural shift from "disposable" to commodity. This can happen with effective communication, active citizens' education, and awareness and engagement in core bioeconomy experiences and activities, like urban waste management and environmental sustainability. Citizen engagement methodologies are multiple. This paper proposes the combined use of Information and Communication Technologies (ICTs), citizens' hands-on project involvement, and a direct rewarding system. Similar European examples are displayed, while our key case study is the bitter orange waste problem in the metropolitan region of Attica in Greece, where approximately 40,000 tons of bitter oranges per year remain unmanageable and unexploited, causing serious problems. The Bitter Orange Project aims to educate citizens on bioeconomy and biomass value, hopefully changing the perception of urban waste through their rewarded engagement in fruit collection to produce high added value materials. This can be a versatile platform for urban waste management projects through citizen science regardless of the type of biomass. The project aims to engage all possible local society stakeholders to multiply awareness. The target of this paper is to highlight that environmental problems related to biomass misuse are closer than the average citizen experiences, and that active involvement of society through rewarding can help raise awareness.

Exposure to bacterial and fungal bioaerosols in facilities processing biodegradable waste.

The aim of the study was to determine the exposure of workers within biodegradable waste processing facilities to bacteria and fungi to identify any exposures of potential concern to health. Occupational measurements were performed in six composting and three bioenergy (bioethanol or methane/biogas) producing facilities. Bioaerosols were measured from breathing zones with Button aerosol or open face cassette filter samplers, and swab specimens were taken from the nasal mucous membranes of the workers. Aspergillus fumigatus, Bacillus cereus group, Campylobacter spp., Salmonella spp., Streptomyces spp., and Yersinia spp. were determined by real-time polymerase chain reaction (qPCR). A. fumigatus, and mesophilic and thermophilic actinobacteria were also cultivated from filters. Bacterial airborne endotoxins collected by IOM samplers were analyzed using a Limulus assay. Bioaerosol levels were high, especially in composting compared to bioenergy producing facilities. Endotoxin concentrations in composting often exceeded the occupational exposure value of 90 EU/m3, which may be harmful to the health. In addition to endotoxins, the concentrations of A. fumigatus (up to 2.4 × 105 copies/m3) and actinobacteria/Streptomyces spp. (up to 1.6 × 106 copies/m3) in the air of composting facilities were often high. Microbial and endotoxin concentrations were typically highest in waste reception and pre-treatment, equal or decreased during processing and handling of treated waste, and lowest in wheel loader cabins and control rooms/outdoors. Still, the parameters measured in wheel loader cabins were often higher than in the control sites, which suggests that the use of preventive measures could be improved. B. cereus group, Salmonella spp., and Yersinia spp. were rarely detected in bioaerosols or nasal swabs. Although Campylobacter spp. DNA was rarely detected in air, as a new finding, Campylobacter ureolyticus DNA was frequently detected in the nasal mucous membranes of workers, based on partial 16S rDNA sequencing. Moreover, especially A. fumigatus and C. ureolyticus spp. DNA concentrations in swabs after the work shift were significantly higher than before the shift, which indicates their inhalation or growth during the work shift. Microbial qPCR analysis of bioaerosols and swab samples of nasal mucosa allowed measuring exposure in various work operations and during the work shift, identifying problems for health risk assessment to improve working conditions, and evaluating the effectiveness of preventive measures and personal protection of workers.

Factors affecting eco-efficiency of municipal waste services in Tuscan municipalities: An empirical investigation of different management models.

The efficient provision of municipal solid waste (MSW) services is essential from an economic and environmental perspective. This paper investigates the effect of ownership type on the eco-efficiency of MSW management in Tuscan municipalities. In the first stage of the analysis, the authors use a data envelopment analysis metafrontier approach with the integration of unsorted waste as an undesirable output. Three different clusters of municipalities are created based on the ownership type of the municipal waste operators: public, private, and mixed. In the second stage of analysis, the paper investigates factors affecting eco-efficiency in order to provide new knowledge that can be used by policy and decision makers to improve eco-efficiency. The results show that eco-efficiency is higher for municipalities that entrust the delivery of waste services to publicly owned firms compared to municipalities with delivery by mixed and private firms. Moreover, eco-efficiency in MSW management is higher for municipalities with younger residents, a larger population, and an overall higher population density. Smaller municipalities and those with less tourism manage their waste services more eco-efficiently than do bigger municipalities and those with more tourism. The results indicate that policy-makers should improve communication and engagement activities with older residents in smaller, less densely populated areas. In municipalities featuring heavy tourism, eco-taxes could be used to support these activities, avoiding any impact on residents.

Motivations for kerbside dumping: Evidence from Brisbane, Australia.

Illegal dumping of waste on kerbsides outside residences is a problem in many urban areas around the world. Despite this, there has been little research undertaken on the reasons behind the practice or the barriers to alternative, legal disposal mechanisms. This study interviewed householders in Brisbane, Australia in an attempt to fill this gap. The interviews revealed that kerbside dumping is a complex behaviour with a variety of motivations. Unlike many other illegal activities, participants and observers of kerbside dumping did not necessarily realise that what they were doing was illegal. They also identified many positive benefits such as sharing items with other people. In addition, some residents felt they had no choice even though they were aware that it was illegal. For them, barriers such as lack of transport to the waste disposal facility and lack of storage until the official kerbside collection meant that the practice continued.

Exploring social and infrastructural factors affecting open burning of municipal solid waste (MSW) in Indian cities: A comparative case study of three neighborhoods of Delhi.

Open municipal solid waste (MSW)-burning is a major source of particulate matter emissions in developing world cities. Despite a legal ban, MSW-burning is observed ubiquitously in Indian cities with little being known about the factors shaping it. This study seeks to uncover social and infrastructural factors that affect MSW-burning at the neighborhood level. We couple physical assessments of the infrastructure provision and the MSW-burning incidences in three different neighborhoods of varying socio-economic status in Delhi, with an accompanying study of the social actors (interviews of waste handlers and households) to explore the extent to which, and potential reasons why, MSW-burning occurs. The observed differences in MSW-burning incidences range from 130 km-2 day-1 in low-income to 30 km-2 day-1 in the high-income areas. However, two high-income areas neighborhoods with functional infrastructure service also showed statistical differences in MSW-burning incidences. Our interviews revealed that, while the waste handlers were aware of the health risks associated with MSW-burning, it was not a high priority in the context of the other difficulties they faced. The awareness of the legal ban on MSW-burning was low among both waste handlers and households. In addition to providing infrastructure for waste pickup, informal restrictions from residents and neighborhood associations can play a significant role in restricting MSW-burning at the neighborhood scale. A more efficient management of MSW requires a combined effort that involves interplay of both social and infrastructural systems.

Três décadas de coleta seletiva em São Francisco (Niterói/RJ): lições e perspectivas / Three decades of source-separation collection of recycling materials in São Francisco (Niterói/RJ, Brazil): lessons and perspectives

RESUMO O artigo apresenta os principais aspectos de uma avaliação da coleta seletiva do bairro de São Francisco em Niterói (RJ), após 28 anos de operação ininterrupta. Destacam-se os seus principais aspectos positivos, como a contribuição na disseminação da importância da coleta seletiva, agora estabelecida como obrigação legal na Política Nacional de Resíduos Sólidos (PNRS), bem como o da participação da população local ao longo dos anos. O fato de ser este trabalho gerenciado pela associação de moradores, o Centro Comunitário de São Francisco (CCSF), estabelece um sentimento de pertinência do morador com o projeto. Também se evidencia a prática de recuperação de materiais culturais que em outras circunstâncias iriam para o lixo, ou, no caso de uma coleta seletiva tradicional, seriam vendidos como material reciclável. Com a receita da venda de, em média, 20 ton/mês de materiais recicláveis, o projeto não consegue cobrir as despesas com quatro empregados registrados e a manutenção dos equipamentos. Depende de apoio externo para subsistir. Isto contribui para a reflexão sobre a necessidade de se definir as fontes de recursos, conforme estabelece a PNRS, para que a coleta seletiva seja implantada nos municípios.

ABSTRACT This work presents the results of an assessment of source-separation collection of recycling materials in São Francisco neighborhood of Niterói municipality in Rio de Janeiro State, Brazil, after 28 years of uninterrupted operation. Main positives aspects are highlighted: its contribution to the dissemination of recycling activity, presently established as a legal municipality obligation by National Policy of Solid Waste (PNRS); the local population participation all these years; and the pertinence feeling of the residents with the project by the fact of the recycling activity be managed by residents' association, the Community Center of São Francisco (CCSF). Also it is highlighted the recovery of cultural materials whose in the mingled waste collection would be thrown out, or in the traditional source-separated collection would be sold as recycling material. Selling an average of 22 tons of recycling materials per month, São Francisco source-separation collection have not been able to cover the costs of the 4 employees and equipment maintenance. So it depends of financial help to exist and may contribute to the reflection about the funding sources to implement recycling collection in the Brazilian municipalities as established by PNRS.