Critical analysis of the integration of residual municipal solid waste incineration and selective collection in two Italian tourist areas

Sustainable tourism in the Tremiti Islands (South Italy)

An analysis of the pressure factors that influence the sustainable tourism in the Tremiti Islands (TI) has been performed. Tourist's fluxes have been investigated in terms of monthly arrival and presences showing a high value of the territorial exploitation index with high number of arrivals, particularly in August, and low occupancy rate. Effects of climatic change has been analyzed in TI with reference to the increase of average air and sea temperature in the islands. Some measures of contrast to climate change and to favour sustainable tourism have been discussed also. The CO2 emissions by ferries transport, solid waste and wastewater treatment have been calculated. Environmental taxation for sustainable tourism aimed tat CO2 content reduction is also assessed identifying the value in 1.47 €/capita on the basis of the tourist arrivals and presences considering the environmental cost for CO2 removal and showing that tourism taxation should be well accepted if funds are destined to environmental purposes.

Low-carbon municipal solid waste management using bio-based solutions and community participation: The case study of cultural tourism destination in Nan, Thailand

Tourism expansion has led to increased municipal solid waste (MSW) generation, which can exacerbate environmental and societal problems if proper waste management systems are not implemented. The study develops a framework for implementing bio-based solutions (BbS) for MSW management in a cultural tourism destination, using the walking street in Nan, Thailand, as a case study. Four low-carbon waste management scenarios were assessed, including increasing recycling rates (RE), using food waste as animal feed (BbS1), using bagasse containers as a soil conditioner (BbS2), and substituting single-use plastics with bamboo products (BbS3). Results showed that the BbS1 scenario had the highest performance in greenhouse gas (GHG) mitigation, reducing 66.3 t CO2e/year, followed by BbS2, RE, and BbS3 scenarios, which reduce GHG by about 12.3, 11, and 1 t CO2e/year, respectively. However, the BbS2 scenario has an additional benefit in returning around 84 kg N/year to the soil. Implementing the combination of RE, BbS1, BbS2, and BbS3 reduced waste to landfills by about 25.5 t MSW/year and reduced GHG emissions by 90.3 t CO2e/year. Enhancing residual waste management is recommended, which can lead to mitigation of about 164.3 t CO2e/year, or 83 % GHG emissions reduction compared to the base case.

Evaluation of greenhouse gas emissions from aerobic and anaerobic wastewater treatment plants in Southeast of Italy

An evaluation of the operative functioning data of 183 Wastewater Treatment Plants (WWTPs) in Apulia (Southeast of Italy) has been carried out aimed to assess their Green House Gases (GHGs) emissions and the level for which the use of anaerobic sludge treatment should be more convenient in terms of electricity consumption and of GHGs emissions. Out of the 183 studies WWTPs, 140 are practicing aerobic digestion of sludge, while the remaining 43 are practicing anaerobic digestion of sludge. WWTPs in Apulia are serving about 4,81 million PE (Population Equivalent), yielding approximately 600,000-ton equivalent CO₂ per annum. The production of GHGs emissions has been estimated by evaluating the contribution of CO₂ deriving from: a) electric energy consumption (fossil CO₂), b) biogenic CO₂, c) N₂O and d) CH₄ emissions. The present study investigates a number of technical measures for upgrading the existing WWTPs, so to reduce GHGs emissions through the amelioration of CH₄ production and capture in the anaerobic step, and through reducing the production of biogenic N₂O and CO₂ emissions in the aerated basin. The methodology employees artificial intelligence-based control for upgrading the aerobic oxidation of the organic carbon and the nitrification-denitrification steps. As a result, GHGs emissions are expected to be reduced by approximately: 71% for CH₄, 57% for N₂O, 20% for biogenic CO₂ and 15% for fossil derived CO₂.

Phytoextraction by Moso Bamboo under high level chromium stress in mediterranean conditions

In this study a bamboo species, Moso Bamboo (MB) - Phyllostachys pubescens - has been selected for its heavy metal accumulation capacity and translocation potential to restore Cr-contaminated soil. Experiments have been conducted so to evaluate the capability of MB to remove Cr from soil, growing under Mediterranean conditions, irrigated with water containing 180 mgCr/L, at flow rate of 600 mm/year. The soil has been contaminated by the irrigation water. When the concentration of Cr in soil reached 300 mgCr/kg, Cr phytoextraction by MB from soil at the same irrigation rate of 600 mm/year with uncontaminated water has been evaluated. Cr removal from soil was approx. 42% after 6 weeks and 60.7% after 12 weeks, starting from a Cr content in soil of approximately 300 mg/kg. MB growing in Cr contaminated soil has shown Cr concentration per gram of dry biomass in aerial parts greater than the underground parts of the plants. After 12 weeks of cultivation, the quantity of Cr in roots and rhizome was measured as 1.79 mg/g, while in stems and leaves as 2.49 mg/g. Results shown a bioconcentration factor of 0.77, 0.65, 0.18, 0.08, after 6 weeks and 0.64, 0.98, 0.53, 0.26 after 12 weeks for roots, rhizomes, stems and leaves, respectively and a translocation factor equal to 0.23 and 0.11 after 6 weeks and 0.83 and 0.40 after 12 weeks, for stems and leaves, respectively.

Chromium phytoextraction using Phyllostachys pubescens (Moso Bamboo)

In this study, a bamboo species, the Phyllostachys pubescens - Moso Bamboo (MB) -, was selected for its heavy metals accumulation and translocation potential to restore Chromium (Cr)-contaminated soil. In order to evaluate the MB Chromium growth, tolerance and the potential for phytoremediation using MB to restore Cr-contaminated soil, pot experiments were carried out in simulated Mediterranean conditions in a laboratory, in a controlled environment, at a temperature of 20 °C. The results showed that MB growth rate was 4.28 cm/week on average, with an irrigation flow of 1.644 mm/d. MB tolerance was tested over a 12-week irrigation period with the addition of Cr-contaminated water. Cr removal from soil was 43% starting from a Cr content of approx. 200 mg/kg dry weight (dw) and the quantity of Cr per gram of root and rhizome was equal to 1.31 mg/g dw, while the quantity of Cr per gram of stem and leaves was equal to 0.86 mg/g dw, after 12 weeks. Pot experiments confirm that phytoremediation using plants such as MB provides an alternative approach for handling Cr-contaminated soil.

Phytoextraction of Cr(VI)-Contaminated Soil by Phyllostachys pubescens: A Case Study

This work presents the results of experimental tests to evaluate the effects of prolonged contamination by Cr on Moso Bamboo (MB) (Phyllostachys pubescens) and the adaptability of the MB to the Mediterranean climate. A preliminary test on the MB was developed in the laboratory, simulating irrigation under Mediterranean conditions (600 mm per year) and tropical conditions (1800 mm per year), to evaluate the rate of growth and the MB’s capability for Cr phytoextraction from contaminated soil. The tolerance of MB to Cr was also performed showing a good response of the plant to 100 mg Cr/L solution, utilized for irrigation of the pots. The results show that the rate of MB’s removal of Cr from soil ranged from 49.2% to 61.7% as a function of the soil degree of contamination, which varied from approx. 100 mg/kg to 300 mg/kg. The distribution of Cr in the various sections of the bamboo revealed that the greater percentage was present in rhizomes: 42%, equal to 114 mg Cr for 600 mm per year, and 50%, equal to 412 mg Cr for 1800 mm per year. A noteworthy diffusion of the metal towards the outermost parts of the plant was shown. The values of Cr retained in the stems and leaves of MB tissues were quite high and varied from 1100 mg/kg to 1700 mg/kg dry weight.

Carbon footprint reduction potential of waste management strategies in tourism

Tourism is one of the major economic factors contributing to growth and jobs worldwide. The number of international travellers has increased more than 50-fold in the past 70 years. However, the contribution of tourism to (municipal) waste generation is also large and is increasing, accompanied by an increase in some environmental and socio-economic impacts. An average value of 1.67 kg waste is now generated per tourist (Obersteiner et al., 2017). Waste prevention and recycling should therefore be major objectives in tourist waste management by municipal authorities. Within the EU H2020-funded project "URBANWASTE - Urban Strategies for Waste Management in Tourist Cities", eco-innovative waste prevention and management strategies were implemented in 10 pilot cities with high levels of tourism, in order to reduce urban waste production and improve municipal waste management. This study examined the potential greenhouse gas (GHG) emissions savings for three selected waste prevention and treatment options: food waste prevention, reductions in single use plastic and increased separate collection and recycling of waste. Benefits were expressed per kg waste prevented or diverted higher up the waste hierarchy and per 1000 tourists. The measures achieved potential GHG emission savings of between 4 and 189 kg CO2-eq. per 1000 tourists, depending on local conditions such as the existing waste management system. Measures tackling food waste reduction and separate collection had low emissions associated with the measure itself, whereas for assessed measures reducing the use of single use plastics by providing reusable alternatives, emissions associated with the measures were relatively high. This was due to the emissions associated with the production of the alternative reusable products. Influencing factors reducing the carbon footprint of waste management in tourism other than the kind of waste focused on were the existing waste management system (especially for biowaste) as well as the practicability and scalability of measures under the divers regional circumstances.

Solid Waste Management Key Indicator Development for Hotels: A Tunisian Case Study Analysis

The main objective of this research was to provide suitable technical, organizational, financial, legal, and social indicators for solid waste management (SWM) systems, which can be used to diagnose the current situation faced by tourist destinations (TD) in Tunisia. To this end, 33 interviews and field visits to hotels in Tunisia were carried out. Specifically, the study covers tourist municipalities, private companies, and environment and tourism authorities. A characterization analysis and a quantification of the solid waste (SW) generated by hotels were also performed. It was found that hotels generate large amounts of mixed SW, especially during the summer period. It represents, for example, 45.5% of the total SW generated per year in Hammamet, and can reach 54.2% during the summer. The interviews indicated that 83% of the hotels collect mixed waste, which is then sent to landfills. The characterization of the SW shows that hotels generate about 58% organic waste, and a minimum of 36% of recyclable waste could be valorized. From a financial point of view, the results indicated that the collected taxes from hotels do not cover the municipalities’ expenses. The findings of the research reported in this paper can be used as a decision-making support.

Gravimetric composition of the rejects coming from the segregation process of the municipal recyclable wastes

Rejects from selective collection are municipal solid waste (MSW) not used for recycling and are, therefore, destined for the landfill in Brazil. Knowledge of the composition and generation of this waste is important for strategically planning public policies that minimize its generation and its negative environmental impacts. However, this portion of MSW is not very well known. Therefore, the aim of this study was to analyze the rejects from the sorting process of the selective waste collection in the municipality of Blumenau, in the State of Santa Catarina, southern Brazil. The studied rejects came from the largest cooperative in the city, and its composition was sorted into 17 categories of 101 samples over the course of one year, with a total of 3893 kg of analyzed rejects. The waste collected by the selective collection of the municipality was evaluated monthly to determine which part of this quantity became rejects and to determine the composition and seasonality of these rejects. The study found that 30.5% of the waste sorted by the cooperative was rejected. Among these rejects, the presence of materials that could be marketed by the cooperative was verified. Hazardous and/or legally prohibited waste were also identified, as were organics, construction and demolition waste, health care waste, electronics, textiles, footwear, batteries, and bulbs. Seasonal analysis indicated a concerning constant generation of health care waste. Aside from that, there was an increase in the generation of waste from electrical and electronic equipment (EEE) during the Christmas period, when a large part of the population discards their EEE. This information is important for the enforcement of the MSW management structure as well as for educational campaigns aimed at the correct separation of waste that should be sent for selective collection.

Sampling, characterisation and processing of solid recovered fuel production from municipal solid waste: An Italian plant case study

This article presents the classification of solid recovered fuel from the Massafra municipal solid waste treatment plant in Southern Italy in compliancy with the EN 15359 standard. In order to ensure the reproducibility of this study, the characterisation methods of waste input and output flow, the mechanical biological treatment line scheme and its main parameters for each stage of the processing chain are presented in details, together with the research results in terms of mass balance and derived fuel properties. Under this study, only 31% of refused municipal solid waste input stream from mechanical biological line was recovered as solid recovered fuel with a net heating value (NC=HV) average of 15.77 MJ kg^-1; chlorine content average of 0.06% on a dry basis; median of mercury <0.0064 mg MJ^-1 and 80th percentile <0.0068 mg MJ^-1. The solid recovered fuel produced meets the European Union standard requirements and can be classified with the class code: Net heating value (3); chlorine (1); mercury (1).

Generation and collection of restaurant waste: Characterization and evaluation at a case study in Italy

Because restaurants (as a division of the hospitality sector) contribute to the generation of commercial and institutional waste, thus representing both a challenge and an opportunity, the objective of the present study was to deepen the knowledge of restaurant waste in terms of the qualitative and quantitative characteristics of waste generation and the performance achievable by the implementation of a separate collection scheme. In this study, the generated waste was characterized and the implemented separate collection was evaluated at a relevant case study restaurant in a coastal tourist area of Central Italy (Marche Region, Adriatic Sea side). The qualitative (compositional) characterization of the generated total restaurant waste showed considerable incidences of, in decreasing order, food (28.2%), glass (22.6%), paper/cardboard (19.1%), and plastic (17.1%). The quantitative (parametric) characterization of the generated restaurant waste determined the unit generation values of total waste and individual fractions based on the traditional employee and area parameters and the peculiar meal parameter. In particular, the obtained representative values per meal were: 0.72kgmeal^-1 for total waste, and ranging, for individual fractions, from 0.20 (for food) to 0.008kgmeal^-1 (for textile). Based on the critical evaluation of some of the resulting unit waste generation values, possible influences of restaurant practices, conditions, or characteristics were pointed out. In particular, food waste generation per meal can likely be limited by: promoting and using local, fresh, and quality food; standardizing and limiting daily menu items; basing food recipes on consolidated cooking knowledge and experience; and limiting plate sizes. The evaluation of the monthly variation of the monitored separate collection, ranging from an higher level of 52.7% to a lower level of 41.4%, indicated the following: a reduction in the separate collection level can be expected at times of high working pressure or the closing of a seasonal business (typical for restaurants in tourist areas); and the monthly variation of the separate collection level is inversely correlated with that of the unit generation of total waste per meal. The interception rates of the different restaurant waste fractions collected separately presented a ranking order (i.e., 96.0% for glass, 67.7% for paper/cardboard, 34.4% for food, 20.6% for metal, and 17.9% for plastic) similar to the order of efficiencies achievable at both small and large urban levels. Finally, the original concept of the customer equivalent person (P_ce) was introduced and behaviorally evaluated at the case study restaurant, providing the values of 0.42 and 0.39kgP_ce^-1day^-1 for the food waste generation and the landfilling of biodegradable waste by the customer equivalent person, respectively. These values were compared, respectively, with the food waste generation per person at the household level and the landfilling of biodegradable waste per inhabitant at the territorial level.

Assessment strategies for municipal selective waste collection schemes

An important strategy to promote a strong sustainable growth relies on an efficient municipal waste management, and phasing out waste landfilling through waste prevention and recycling emerges as a major target. For this purpose, effective collection schemes are required, in particular those regarding selective waste collection, pursuing a more efficient and high quality recycling of reusable materials. This paper addresses the assessment and benchmarking of selective collection schemes, relevant to guide future operational improvements. In particular, the assessment is based on the monitoring and statistical analysis of a core-set of performance indicators that highlights collection trends, complemented with a performance index that gathers a weighted linear combination of these indicators. This combined analysis underlines a potential tool to support decision makers involved in the process of selecting the collection scheme with best overall performance. The presented approach was applied to a case study conducted in Oporto Municipality, with data gathered from two distinct selective collection schemes.

Waste prevention impacts on small municipalities: Three experiences from northern Italy

Waste management is an important issue all over the world and it will become even more urgent in the near future due to the increase of global volumes of waste. Waste prevention is at the top of the European waste hierarchy, followed by reuse, recycling, other recovery (including energy recovery), and safe disposal. In Italy, municipalities are the authorities that concretely choose the prevention actions to be applied in their territory and therefore they are crucial in promoting a decrease in waste amounts. In our research we investigated costs and benefits of prevention actions in three small municipalities in the north of Italy. We found that the "Pay as You Throw" (PAYT) scheme is an effective action in preventing waste production, with many instances, on analyzing the collection data. The specific effect of the other actions (such as the awareness raising campaigns) is difficult to isolate, even if we found positive impacts. We analyzed some external drivers, such as the migration effect, in order to understand the real effectiveness of the implemented actions. One of the objectives of the study was to comprehend the consequences of political choices at a bigger scale than the individual municipality. Analyzing the results obtained in three typical small Italian municipalities, this study suggests that local authorities, with their choices, can greatly affect the efficacy of selected waste collection and waste prevention.

Identification of influencing municipal characteristics regarding household waste generation and their forecasting ability in Biscay

The planning of waste management strategies needs tools to support decisions at all stages of the process. Accurate quantification of the waste to be generated is essential for both the daily management (short-term) and proper design of facilities (long-term). Designing without rigorous knowledge may have serious economic and environmental consequences. The present works aims at identifying relevant socio-economic features of municipalities regarding Household Waste (HW) generation by means of factor models. Factor models face two main drawbacks, data collection and identifying relevant explanatory variables within a heterogeneous group. Grouping similar characteristics observations within a group may favour the deduction of more robust models. The methodology followed has been tested with Biscay Province because it stands out for having very different municipalities ranging from very rural to urban ones. Two main models are developed, one for the overall province and a second one after clustering the municipalities. The results prove that relating municipalities with specific characteristics, improves the results in a very heterogeneous situation. The methodology has identified urban morphology, tourism activity, level of education and economic situation as the most influencing characteristics in HW generation.