The use of waste-derived paste as daily cover materials for enhancing geo-environmental performance of sanitary landfills

The use of earth materials as daily covers in sanitary landfills not only consumes valuable landfill space, but also creates a series of technical and operating issues. Column tests were conducted to study fines migration from traditional soil covers. Moisture content at compaction, cover thickness, and soil-waste interface were the most influential parameters on fines migration. The sizes of migratory fines were in the range of 4–140 μm. The majority of migratory fines migrated during first permeations, representing 64–86% of the total mass of fines. Seeping velocity was believed to be responsible for the detachment and transportation processes. An innovative synthetic paste of waste tire chips and paper sludge was, therefore, developed for landfill daily cover applications. The engineering properties and behaviours of the proposed paste were studied through a series of laboratory tests. When compared to traditional soil covers, the paste was: (i) 2–3 times lighter in weight; (ii) at least two orders of magnitude more impermeable; and (iii) comparable in shear resistance. The shear strength of the paste was considerably higher than the parent materials. The reinforcing mechanisms were examined and quantified, suggesting an optimal of tire chips in the paste of about 55%. The environmental benefits of the paste were demonstrated using column tests. An equilibrium deterministic transport model was used to fit the transport parameters from the breakthrough curves of Pb. Analysis of the effluent concentrations displayed retardation effect in all cases, with fitted retardation factors from 19.9 to 59.0. Early arrivals of solute were observed unexpectedly in columns with high paper sludge content and might be attributed to the presence of non-uniform flow. It is believed that a set of operational, mechanical and environmental benefits can be obtained by using the proposed paste. Engineering significances of the work are included

Temporal and Spatial Distributions of Waste Facilities and Solid Waste Management Strategies in Rural and Urban Saskatchewan, Canada

Saskatchewan has the highest number of landfills per capita in Canada. Given the lower population density and the skewed spatial population distribution, comprehensive analysis of municipal solid waste management systems in Saskatchewan is inherently difficult. Most of the published waste studies however focus on city-level waste management, and there is a lack of literature with respect to the rural areas. In this study, landfills and transfer stations are examined temporally and spatially using Geographic Information System. Landfills and transfer stations from 2017 and 2020 were plotted against census division land area, annual budget, and population density to study temporal changes. Saskatchewan witnessed a 54% reduction in the number of landfills and a 55% increase in number of transfer stations between 2017 and 2020. The replacement of landfills with transfer stations are more noticeable in divisions 8, 9, and 16. Regression analysis is conducted, and landfill closure operation show no obvious correlation to division land area, annual budget, or population density. Rural division 18, representing Northern Saskatchewan, has approximately 45% of the land area in the province and has the lowest population density. The findings suggest different waste management strategies are required for urban and rural areas. The results of this study will help policy makers to better implement solid waste management strategies in urban and rural areas

Mapping and Prioritizing Potential Illegal Dump Sites Using Geographic Information System Network Analysis and Multiple Remote Sensing Indices

Due to rapid urbanization and population growth, identification and management of illegal dump sites has been a global challenge. In this study, satellite imagery and geographic information system were used to map potential illegal dump sites (PIDS). An original analytical approach was developed to identify PIDS using a set of remote sensing indices and vector files. The Network Analysis tool was used to prioritize PIDS considering driving distance between PIDS and neighboring populated points. A total of five variables (Landfills, LST, HCHO, Highways, and EVI) were considered. A study area in Saskatchewan, Canada, was selected, and the identified PIDS account for about 37.3% of the total area. Road network intensity and accessibility appear important to the occurrence of PIDS. Overall road densities in identified PIDS ranged from 0.098 to 0.251 km/km2. All five variables have observable effects on the occurrence of PIDS; however, LST and highways are recommended for future studies due to their higher membership grade and spatial sensitivity. The combination of multiple remote sensing indices and network analysis on PIDS prioritization is advantageous. The proposed PIDS mapping and prioritization method can be easily employed elsewhere

Exploring the Market Requirements for Smart and Traditional Ageing Housing Units: A Mixed Methods Approach

The world’s population is getting older these days. Frailty, a gerontologic health condition associated with ageing, has serious consequences. One crucial remedy for the elderly population is the development of ageing-in-place infrastructures. To better understand the market requirements for ageing housing units, the causes of downsizing and the governmental measures to ameliorate the situation, face-to-face in-depth individual and focus group interviews were conducted in this study. Elderly residents of two significant ageing-in-place institutions in Hong Kong, along with their caregivers, were interviewed. The method of methodological triangulation was used to combine interviews, records, and communication tools to increase the reliability and trustworthiness of the findings. The provision of facilities for the elderly has successfully established a pathway for creating and making housing spaces available to families who need larger homes, while the elderly typically downsize from larger homes and relieve their financial needs. It is also found that a digital divide exists; some respondents suggested that they do not know about computers and do not use smart facilities in their homes

Exploring the Market Requirements for Smart and Traditional Ageing Housing Units: A Mixed Methods Approach

The world’s population is getting older these days. Frailty, a gerontologic health condition associated with ageing, has serious consequences. One crucial remedy for the elderly population is the development of ageing-in-place infrastructures. To better understand the market requirements for ageing housing units, the causes of downsizing and the governmental measures to ameliorate the situation, face-to-face in-depth individual and focus group interviews were conducted in this study. Elderly residents of two significant ageing-in-place institutions in Hong Kong, along with their caregivers, were interviewed. The method of methodological triangulation was used to combine interviews, records, and communication tools to increase the reliability and trustworthiness of the findings. The provision of facilities for the elderly has successfully established a pathway for creating and making housing spaces available to families who need larger homes, while the elderly typically downsize from larger homes and relieve their financial needs. It is also found that a digital divide exists; some respondents suggested that they do not know about computers and do not use smart facilities in their homes