The Impact of Solid Waste Generation, Storage and Separation Practices among Households on the Environment in Freetown

As urbanization and population growth continue to increase in Freetown, due to changes in economic, social, environmental, political, and demographic factors, the municipal solid waste (MSW) generation also continues to increase, making its management difficult for the municipal authority. Efficient separation and storage of solid waste at the source of generation can boost resource and energy recovery from MSW. This study examines the municipal solid waste management (MSWM) process, focusing on generation, storage and separation practices among households and their impact on the environment in Freetown. It emphasizes the inclusion of MSWM programs in primary schools to raise public awareness, the implementation of effective waste management practices, and the enforcement of related policies to enhance the MSWM sector, contributing to sustainable MSWM in Freetown. By utilizing both qualitative and quantitative methods, 393 structured questionnaires were administered across three selected sections to collect data on household solid waste storage and separation practices. The analysis employed descriptive statistics, using Origin-Pro9 and MS Excel. The findings show that with a population of 1.53 million people in Freetown, the per capita solid waste generation is 0.58 kg per day. The findings also show that 97% of the households have storage facilities as a result of the increase in awareness and education about the proper storage of solid waste. However, 96% of respondents do not practice separation of solid waste at the source of generation, which has become a concern among researchers in Sierra Leone. Additionally, 88% of respondents are unaware of ISWM principles, with only 12% aware, most of whom have received some education on proper solid waste management. The study recommends improving MSWM in Freetown to protect public health and the environment.

Application of Multivariate Reinforcement Learning Engine in Optimizing the Power Generation Process of Domestic Waste Incineration

Garbage incineration is an ideal method for the harmless and resource-oriented treatment of urban domestic waste.However,current domestic waste incineration power plants often face challenges related to maintaining consistent steam production and high operational costs.This article capitalizes on the technical advantages of big data artificial intelligence,optimizing the power generation process of domestic waste incineration as the entry point,and adopts four main engine modules of Alibaba Cloud reinforcement learning algorithm engine,operating parameter prediction engine,anomaly recognition engine,and video visual recognition algorithm engine.The reinforcement learning algorithm extracts the operational parameters of each incinerator to obtain a control benchmark.Through the operating parameter prediction algorithm,prediction models for drum pressure,primary steam flow,NOx,SO2,and HCl are constructed to achieve short-term prediction of operational parameters,ultimately improving control performance.The anomaly recognition algorithm develops a thickness identification model for the material layer in the drying section,allowing for rapid and effective assessment of feed material thickness to ensure uniformity control.Meanwhile,the visual recognition algorithm identifies flame images and assesses the combustion status and location of the combustion fire line within the furnace.This real-time understanding of furnace flame combustion conditions guides adjustments to the grate and air volume.Integrating AI technology into the waste incineration sector empowers the environmental protection industry with the potential to leverage big data.This development holds practical significance in optimizing the harmless and resource-oriented treatment of urban domestic waste,reducing operational costs,and increasing efficiency.

Synergism of solar-driven interfacial evaporation and photo-Fenton Cr(Ⅵ) reduction by sustainable Bi-MOF-based evaporator from waste polyester

The integration of interfacial solar steam generation and photocatalytic degradation technology has pro-vided a promising platform to simultaneously produce freshwater and degrade pollutants.However,con-structing low-cost,multi-functional evaporators for treating Cr(Ⅵ)-polluted water remains challenging,and the synergistic mechanism on Cr(Ⅵ)reduction is fuzzy.Herein,we propose the combined strategy of ball milling and solution mixing for the sustainable production of Bi-MOF microrod from waste poly(ethylene terephthalate),and construct Bi-MOF-based solar evaporators for simultaneous photo-Fenton Cr(Ⅵ)reduction and freshwater production.Firstly,the evaporator comprised of Bi-MOF microrod and graphene nanosheet possesses high light absorption,efficient photothermal conversion,and good hydro-philic property.Attributing to the advantages,the hybrid evaporator exhibits the evaporation rate of 2.16 kg m^(-2) h^(-1) and evaporation efficiency of 87.5%under 1 kW m^(-2) of irradiation.When integrating with photo-Fenton reaction,the Cr(Ⅵ)reduction efficiency is 91.3%,along with the reaction kinetics of 0.0548 min^(-1),surpassing many advanced catalysts.In the outdoor freshwater production and Cr(Ⅵ)reduction,the daily accumulative water yield is 5.17 kg m^(-2) h^(-1),and the Cr(Ⅵ)reduction efficiency is 99.9%.Furthermore,we prove that the localization effect derived from the interfacial solar-driven evap-oration enhances H_(2)O_(2) activation for the photo-Fenton reduction of Cr(Ⅵ).Based on the result of density functional theory,Bi-MOF microrod provides rich active centers for H_(2)O_(2) activation to produce active sites such as e-or-O_(2).This study not only proposes a new strategy to construct multi-functional solar evaporators for freshwater production and catalytic reduction of pollutants,but also advances the chem-ical upcycling of waste polyesters.

Current Situation Analysis and Suggestions for Solid Waste Management Practices among Households in Freetown

Freetown which is the capital city of Sierra Leone is facing challenges with population growth, urbanization, and industrialization, leading to an increase in municipal solid waste (MSW) generation. The study aims to evaluate MSW generation, composition, and disposal methods, as well as the impact of collection fees, policy implementation, and women’s participation in municipal solid waste management (MSWM). The study used both qualitative and quantitative methods for data collection and analysis. The study administered 393 structured questionnaires in three selected sections to collect data on variables such as family size, education, level of knowledge, etc. The study used door-to-door data collection to determine the rate of solid waste generation, composition, and disposal in 66 households from two of the selected sections and 34 households from the other section to evaluate the current situation of MSWM practices among households in Freetown. The study used a descriptive statistic to analyze the data collected using Origin-Pro9 and MS Excel software. The findings showed that with a 4.2% urban growth rate, Freetown had a population of 1,467,543 in 2023, generating 851 tons of MSW per day, with organic waste accounting for 78% of the total MSW generated. Plastic waste generation also increased from 7.6% in 2020 to 13% in 2023. The study emphasizes the need to sustain the MSWM system by prioritizing solid waste collection fees, policy enforcement, and women’s participation in the MSWM sector. It further suggests and provides recommendations for developing an efficient and sustainable MSWM system in Sierra Leone, including knowledge transfer from countries like China and the US.

Comment on the development and policy of the waste incineration power generation industry

Development space of the waste incineration power generation is expanding. According to the technical route of previous planning and related policies, the principles of our garbage disposal are based on sanitary landfill, supplemented by burning. However, with the accelerated process of urbanization, land resources are increasingly strained and most large cities have been unable to find a suitable landfill within the feasible urban extent, the main equipment for the incinerator and the localization of the overall process greatly reduced its capital investment and these factors will promote the rapid development of waste incineration power generation industry. Waste incineration and power generation technology has the dual benefits of environmental protection and energy and it is the development direction of waste disposal in the future. According to the condition that our country＇s waste incineration power generation started from scratch and developed rapidly in recent years ,there is a introduction about the application of the waste incineration and a brief analysis of the its obstacles in the promotion and financing, as well as the potential for future applications.

Determination and Evaluation of the Rate of Solid Wastes Generation in Health Care Centers in Montevideo, Uruguay

Decree 586/009 establishes the main guidelines related to the management of Health Care Wastes (RAS). For this reason, it is used as a reference in the definition of any methodological proposal that intends to address all the aspects related to Intra-institutional Management of Residues generated in Health Care Centers (CAS) in Uruguay. In the first instance, this paper presents an application case based on the experience of previous work in a CAS in Montevideo. Providing special importance to the Evaluation of rates of sanitary waste removal rates in the hospital centers, which were determined based on historical data for the period from 2008 to 2011, referring to rates of removal of contaminated, common and recyclable sanitary waste. Based on the analysis of these data, information on their behavior is obtained, such as: number of common waste removed per day in the period, evolution of the monthly average of the daily rate of removal of common waste, evolution of the average daily waste removal rate from month to month in the period, average daily waste removal rate for each month of the year in the period considered, average daily rate of common waste removal for each day of the week, evolution of the monthly average of the daily rate of removal of contaminated waste, evolution of the monthly average daily withdrawal rate of contaminated waste in the period and mean of the daily rate of removal of contaminated waste for each month of the year in the period considered. Finally, the conclusions of this article present the procedure to perform a weighing campaign, which should be carried out to determine the common and contaminated waste generation rates in each of the main services of the CAS.

Efficiency analysis of trilateral-cycle power systems for waste heat recovery-to-power generation

Numerous innovative heat recovery-to-power technologies have been resourcefully and technologically exploited to bridge the growing gap between energy needs and its sustainable and affordable supply.Among them,the proposed trilateral-cycle(TLC) power system exhibits high thermodynamic efficiency during heat recovery-to-power from low-to-medium temperature heat sources.The TLCs are proposed and analysed using n-pentane as working fluid for waste heat recovery-to-power generation from low-grade heat source to evaluate the thermodynamic efficiency of the cycles.Four different single stage TLC configurations with distinct working principles are modelled thermodynamically using engineering equation solver.Based on the thermodynamic framework,thermodynamic performance simulation and efficiency analysis of the cycles as well as the exergy efficiencies of the heating and condensing processes are carried out and compared in their efficiency.The results show that the simple TLC,recuperated TLC,reheat TLC and regenerative TLC operating at subcritical conditions with cycle high temperature of 473 K can attain thermal efficiencies of 21.97%,23.91%,22.07% and 22.9%,respectively.The recuperated TLC attains the highest thermodynamic efficiency at the cycle high temperature because of its lowest exergy destruction rates in the heat exchanger and condenser.The efficiency analysis carried out would assist in guiding thermodynamic process development and thermal integration of the proposed cycles.

Effect of Leachate Recirculation on Settlement and Leachate Generation of Municipal Solid Waste from Landfill Lysimeter

The objectives of this study are to determine the settlement and leachate generation from landfill lysimeters of municipal solid waste. Two identical lysimeters with a diameter and height of 0.70 m and 2.40 m were prepared, respectively. The lysimeters were operated with and without leachate recirculation treatment. The settlement and leachate generation were quantified daily. The analysis of settlement was conducted by using hyperbolic function and curve fitting. Based on the experiments result, it is observed that garbage pile settlement in lysimeter treated with leachate recirculation （L-2） is higher than without recirculation treatment （L-1） as showed by the hyperbolic function and curve fitting result. The ultimate settlement （S_wlt） for L-1 and L-2 that used hyperbolic function were 0.487 m and 0.53 m, respectively. Meanwhile （S_wlt） that using curve fitting resulted 0.74 m, and 0.68 m for L-1 and L-2, respectively. The lysimeter which treated with leachate recirculation treatment showed a higher leachate height than without the treatment.

A Situational Assessment of Socioeconomic Factors Affecting Solid Waste Generation and Composition in Freetown, Sierra Leone

The generation of solid waste has become an increasing environmental and public health problem, especially in developing countries. These problems associated with the generation of solid waste are part of social changes where households play an important role. Invariably, these social changes influence the size, structure and characteristics of given households. This paper presents the findings of a study carried out in Freetown municipal area in Sierra Leone to assess socioeconomic factors affecting household solid waste generation and composition in Freetown, Sierra Leone. Structured questionnaires were administered with respect to these socioeconomic factors in four (4) selected constituencies of the city. These are the most populated constituencies that generated 70% of the total quantity of solid waste in the city. Therefore, they are suitable samples of the study area. The rate of waste generation was determined by using door- to-door approach in five (5) selected households from each constituency through sorting and weighing of solid wastes respectively. The dependent variables were solid waste generation and composition, and the independent variables were family size, education, income levels among others. The data obtained were subjected to statistical analysis to determine relationships between independent variables and dependent variables through correlation. The results showed that the solid waste generation and composition in Freetown was significantly affected by average family size, employment status, monthly income, and number of room(s) occupied by households. In general, the paper adequately suggests new insights concerning the role of socioeconomic factors in affecting the generation and composition of household solid waste.

Household Solid Waste Generation and Composition: A Case Study in Palapye, Botswana

The purpose of this case study was to conduct a case study in the generation rate, composition, and characterise solid wastes from low, middle and high income households during weekdays and weekends in Palapye, Botswana. The study was conducted through sampling and analysis of the wastes from sampled households from each of the three categories. Palapye village does not have an engineered solid waste management system in place;hence the study can be used as a starting point. The village is rapidly urbanising with many shopping complexes coming up which will generate high amounts of solid wastes of different compositions. The lowest generation rate was 0.038 kg/capita/day from low income households during weekends and the highest was 0.364 kg/capita/day generated from high income households during weekends. The composition of the wastes was dominated by food wastes ranging from 46.44% to 80.78% with low income households generating the highest percentage during weekdays. The average moisture contents of samples from low, middle and high income households were 71% ± 0.0%, 66.3% ± 1.25% and 74.3% ± 2.2% respectively during weekdays compared to 77% ± 0.0%, 66.5% ± 3.5% and 69.3% ± 3.3% during weekends. The average moisture contents from low, middle and high income households were 71% ± 0.0%, 66.3% ± 1.25% and 74.3% ± 2.2% respectively during weekdays compared to 77% ± 0.0%, 66.5% ± 3.5% and 69.3% ± 3.3% during weekends. The results can be used as part of the waste management planning purpose by the Administrative Council of the area.

Generation, Characterization and Management Practices of Household Solid Wastes in Cowfield, Paynesville City, Liberia

The success of any waste management system requires accurate and up-to-date data on quantity, composition of waste. Waste generation data from household are needed to address issues relating to municipal solid wastes such as management method, performance improvement, policy, regional and local planning, administrative, cost accounting, design and operation of landfill facilities and environmental quality. This study was conducted to provide empirical data on generation rates, quantity and composition, management practices, challenges and strategies from urban household. Waste collection, weighing, questionnaires survey and field observation were methods used during the study. Waste was collected and weighed from 60 households using multi-stage sampling technique for seven days. Questionnaires were analyzed using Statistical Package for Social Sciences version 20 and Excel. A total of 1125.2 kg of waste was recorded. The average household waste generation was 3 kg per day with per capita generation rate of 0.41 kg/cap/day. The compositional analysis showed that Organic (53%), Plastic (11%), Textile (6%), Metal (2%), Glass (1%), Paper and Cardboard 4% and others (22%). Solid waste management practices are very rudimentary. Burning (53.7%) and Open Dumping (30%) were found to be the most commonly used method of disposal with very limited collection service (33.3%) and segregation. The most challenges faced by households were communal disposal area (66.7%) and waste service providers (21.7%) storage bins (11.6%). Waste to energy (48.3%) and compositing (23.3%) were the most considered option for waste management by the respondents.

Estimation of the Solid Waste Generation and Recycling Potential of the Hotel Sector: A Case Study in Hue City, Vietnam

This study examined the solid waste generation and recycling potential of the hotel sector in Hue City, Vietnam. The authors conducted waste measurement, waste composition, and questionnaire surveys for 45 target hotels over ten consecutive days. The waste generation rates (WGRs) by rooms, beds, guests, and workers were assessed by hotel class using the following three waste categories, considering informal waste collection: general waste (GW), separated recyclables (SRe), and separated food residue (SFR). The 5-star hotels exhibited the highest WGR per room at 1.61 kg/room/day, while 1-star hotels exhibited the lowest per-room WGR (0.39 kg/room/day). Spearman Rank correlation test revealed that hotel class and per-room, per-bed, and per-guest WGRs were significantly positively correlated (p < 0.01). The major components of GW were food waste (40.9% to 57.4%), paper (10.1% to 20.3%), and plastic (10.7% to 15.5%). The recycling and composting potentials remaining in the GW were 19.3% to 38.5% and 38.0% to 57.9%, respectively. Based on the WGRs and waste composition determined in this study, the estimated total amount of waste generated was 6.88 tons/day (6.26 to 7.62 tons/day, 95% CI), of which 4.37 (64%), 2.13 (31%), and 0.38 tons/day (6%) were GW, SFR, and SRe, respectively. The recycling and composting potentials remaining in GW were 0.94 (13%) and 2.57 tons/day (37%), respectively. High-class hotels should be considered as the highest priority targets for a “reduce, reuse, recycle” (3R) promotion campaign in the future, with estimated recycling and composting potentials of 0.27 (4%) and 1.10 tons/day (16%), respectively.

Solid Waste Generation and Composition in Mexico： A Comparison between Rural and Urban Communities

This paper reports a generation and composition analysis of household solid waste in Mexico, using as a reference the characterization study performed in two communities, one urban and one rural. Data obtained are fundamental parameters for the planning of urban solid waste management systems in Mexico, complying this way with the established policy in the National Program for Waste Management and Prevention 2009-2012. The study was carried out during five days and two main parameters were assessed： （1） the daily generation rate per person and （2） the waste composition. The per capita waste generation was 0.958 kg for the urban community and 0.631 kg for the rural. The results showed that the mean composition of waste from both locations was statistically similar （a = 0.05）. In both locations the most important contribution was the fraction of food waste. In both locations more than 60% of the waste is potentially recyclable. The results of this study will be used by the municipal waste authorities in order to establish an integrated waste management plan.

Analysis of the Per Capita Generation of Municipal Solid Waste by Socioeconomic Strata in Veracruz, Mexico, Using a Statistical Experimental Design

The management of municipal solid waste （MSW） is currently one of the major environmental concerns in Mexico. Therefore, municipalities must develop local programs for prevention and integrated management of MSW based on the data of MSW generation; however, these are scarce and diffuse. It is known that the MSW generation is affected by many factors, including life level. Given the importance of having reliable data, the objective of this study was to determine the per capita MSW generation of a small urban locality in the state of Veracruz and test whether there were significant statistic differences of per capita M SW generation among the life levels. The households were randomly sampled according to the Mexican standard of reference and were classified as popular, middle and residential. The per capita MSW generation determined was 0.355 kg·inhab^-1.day^-1. This value was lower than the value estimated by the national reference, suggesting that it might be overestimated and consequently lead to errors in estimating installations costs for the MSW treatment. The result of the experimental design revealed that there were significant statistic differences in the per capita MSW generation among the three socioeconomic strata. This study will allow the municipality to establish better strategies within the municipal program and differential rate for the provision of public clean service and it also provides a solid basis for future research under similar conditions.

Comparative Study on Distributed Waste Pyrolysis Cold Emission Energy Station and Incineration Power Generation

The proper terminal disposal of organic solid waste such as domestic waste is a worldwide issue.Landfill covers a large area,with limited capacity,and a single landfill will be filled one day;incineration is costly to build and operate.These methods all need to transfer and centralized treatment,and secondary pollution is difficult to control,against the purification law of the nature."NIMBY effect"is very serious,and the social cost of treatment is increasing,becoming a heavy financial burden."The Distributed Waste Pyrolysis Cold Emission Energy Station"developed by Hunan Zhongzhou Energy-Saving Technology Co.,Ltd.overcomes these disadvantages and constructs a more appropriate environmental economic industrial chain for the treatment of organic solid waste such as urban and rural household waste.Based on its technical characteristics,this paper compares it with waste incineration power generation project in the aspects of secondary pollution control,treatment effect,energy utilization,investment and operation economy,etc.

An empirical analysis of comprehensive benefits of waste power generation

With the rapid development of economy, the scale of city has become more and more large. Meanwhile, the population also grows rapidly. Although the standard of living condition has been improved greatly, industry and domestic waste not only infl uence the quality of life by polluting the environment, but also become a signifi cant obstacle factor for economic development. waste power generation or waste-to-energy(WTE) is using the heat which is from garbage incinerator to generate electricity. This method can solve the problem of waste and generate the social benefi t, but by using the power on the internet to generate the economy benefit. In this paper, combined the method of FAHP and TOPSIS, a quotas system is set up to evaluate the social and economic benefi ts of the WTE project in Xiamen. Some advice is proposed for the Xiamen WTE project.

Study on China＇s Policy Text for Municipal Solid Waster Power Generation

Chinese government has initiated many preferential policies for supporting the circular economy, including the industry of municipal solid waste （MSW） power generation. This paper collects relevant policies for China＇s MSW power generation. It also analyzes the overall environment of policies for the MSW power generation from three aspects---the basic principles for China to develop MSW power generation, the operating mechanism and the specific preferential policies. The analysis establishes foundation for further research toward policy integration.

Power Generation from Municipal Solid Waste Plastics

Generation of electrical energy from imported fossil fuels is subject to the price fluctuations of the global marketplace and, thus, constitutes a major expense in its distribution to the end users. Even with the current low prices of fuel, residents and businesses in the United States pay a significant price for their utilities, if not higher than most other countries in the world. Emissions from the evaporation and combustion of these traditional fossil fuels contribute to a range of environmental and health problems, causing poor air quality, and emitting greenhouse gases that contribute to global warming. Alternative fuel created from domestic sources has been proposed as a solution to these problems and much alternative energy are being developed based on solar, wind, biomass, hydropower, fuel cell, geothermal, etc. A new alternative hydrocarbon fuel which is produced from waste plastics can be used with compatble power plants and generators appliances to produce electricity that can be supplied into homes, businesses, power grids and other sectors.

Assessment of Electric Power Generation via Water Hyacinths and Agricultural Waste

The importance and the necessary of researches on renewable energy have become a hot topic in recent years due to climate change and global warming. In addition, the fossil fuel reserves is facing rapid depletion on the earth. Currently, most researches have concentrated on producing biogas for heating, lighting, drying, cooking but lack in researching on electricity production because the possibility of producing biogas at households are common at small scale. Studying on alternative energy sources to replace traditional fuel for electric power generation brings new chances and great opportunities for development. This study presents an assessment electric power generation via water hyacinths and agricultural waste. In this paper, the evaluation electric power is generated by operating internal combustion engines which use biogas fuel to replace traditional fuel （diesel, gasoline）. The results of the studies were demonstrated by experiments on the renewable energy production system at Hoa An Biotechnology Research and Experimental Center of Cantho University.

Optimal Analysis of Pure Low-Temperature Waste Heat Recovery Generation System

In this paper, a detailed thermodynamic analysis of the pure low-temperature waste heat recovery generation system is presented. The parameters affecting the system performance are compared to obtain the most significant ones; furthermore, parameter values are optimized for the largest power generating capability of the system. It is found that the most important parameters are inlet flue gas temperature, steam pressure and the pinch point temperature difference. There is an optimal superheated steam pressure value for giving the maximum generation power per unit flue gas. With the increase of inlet flue gas temperature, the generating power increases and the optimized steam pressure rises as well. However, with increase in pinch point temperature difference, the generating power decreases and the optimized steam pressure decreases as well. The theoretical calculation provides a theoretical basis for the parameters optimization in the design of the pure low-temperature waste heat recovery eeneration swtem