The residential energy futures of Bhutan.

It is expected that with the increase in population and modernization of any country, energy consumption would increase. Bhutan is a carbon-negative country and committed to remaining carbon-neutral. Thus, identifying energy-saving potential will increase energy efficiency and contribute to continue fulfilling this pledge for years to come. This study aims to find the energy-saving potential of Bhutan by analyzing future energy demand from the residential building sector using a scenario-based modeling tool called Long-range Energy Alternatives Planning (LEAP). The research was an integration of primary and secondary data calculations. Final energy-savings from Bhutan in 2040 by attaining the efficient scenario is estimated at 830 GWh. Overall, the result suggests that 53% final energy-savings can be achieved in 2040 from all end-uses and energy sources compared to the reference scenario. Cumulatively, 19 TWh final energy-savings can be achieved in the study period (2018-2040) from the efficient scenario while all basic energy needs are fully met in 2040. This result obtained would provide a reference for Bhutan's future energy planning and guidelines for policy-making. It would also provide policy recommendations about the scope of shifting to energy-efficient end-uses.

Review of global sanitation development.

The implementation of the United Nations (UN) Millennium Development Goals (MDGs) and Sustainable Development Goals (SDGs) has resulted in an increased focus on developing innovative, sustainable sanitation techniques to address the demand for adequate and equitable sanitation in low-income areas. We examined the background, current situation, challenges, and perspectives of global sanitation. We used bibliometric analysis and word cluster analysis to evaluate sanitation research from 1992 to 2016 based on the Science Citation Index EXPANDED (SCI-EXPANDED) and Social Sciences Citation Index (SSCI) databases. Our results show that sanitation is a comprehensive field connected with multiple categories, and the increasing number of publications reflects a strong interest in this research area. Most of the research took place in developed countries, especially the USA, although sanitation problems are more serious in developing countries. Innovations in sanitation techniques may keep susceptible populations from contracting diseases caused by various kinds of contaminants and microorganisms. Hence, the hygienization of human excreta, resource recovery, and removal of micro-pollutants from excreta can serve as effective sustainable solutions. Commercialized technologies, like composting, anaerobic digestion, and storage, are reliable but still face challenges in addressing the links between the political, social, institutional, cultural, and educational aspects of sanitation. Innovative technologies, such as Microbial Fuel Cells (MFCs), Microbial Electrolysis Cells (MECs), and struvite precipitation, are at the TRL (Technology readiness levels) 8 level, meaning that they qualify as "actual systems completed and qualified through test and demonstration." Solutions that take into consideration economic feasibility and all the different aspects of sanitation are required. There is an urgent demand for holistic solutions considering government support, social acceptability, as well as technological reliability that can be effectively adapted to local conditions.

Toilet revolution in China.

The wide-spread prevalence of unimproved sanitation technologies has been a major cause of concern for the environment and public health, and China is no exception to this. Towards the sanitation issue, toilet revolution has become a buzzword in China recently. This paper elaborates the backgrounds, connotations, and actions of the toilet revolution in China. The toilet revolution aims to create sanitation infrastructure and public services that work for everyone and that turn waste into value. Opportunities for implementing the toilet revolution include: fulfilling Millennium Development Goals and new Sustainable Development Goals; government support at all levels for popularizing sanitary toilet; environmental protection to alleviate wastewater pollution; resource recovery from human waste and disease prevention for health and wellbeing improvement. Meanwhile, the challenges faced are: insufficient funding and policy support, regional imbalance and lagging approval processes, weak sanitary awareness and low acceptance of new toilets, lack of R&D and service system. The toilet revolution requires a concerted effort from many governmental departments. It needs to address not only technology implementation, but also social acceptance, economic affordability, maintenance issues and, increasingly, gender considerations. Aligned with the ecological sanitation principles, it calls for understanding issues across the entire sanitation service chain. Public-private partnership is also recommended to absorb private capital to make up the lack of funds, as well as arouse the enthusiasm of the public.

Household waste and health risks affecting waste pickers and the environment in low- and middle-income countries.

Household waste has evolved into a core urban challenge, with increased quantities of waste being generated and with more complex material compositions, often containing toxic and hazardous elements. Critical systems theory understands cities as urban metabolisms, with different material and energy flows, highlighting the circularity in production, consumption, and discard. Waste pickers in low- and medium-income countries work on dumps and landfills, sifting through highly contaminated household waste and are exposed to health hazards. This paper discusses the risk factors, hazards, and vulnerabilities waste pickers are exposed to during collection and separation of recyclables, based on the review of literature on waste and environmental health and on findings from participatory research with waste pickers conducted in Brazil. We take a social and environmental justice perspective and identify the vulnerabilities and waste-borne hazards of household waste, associated with these workers, their communities, watersheds, and the environment. Household waste, although not always per se toxic or hazardous, can become a hazard if not collected or inadequately managed. Those communities where household waste is not collected or waste collection is insufficient are the most critical places. Informal and organized waste pickers, municipal or private waste collectors/workers, small waste traders and sometimes residents, particularly small children, may be considered vulnerable if exposed to waste-borne hazards. The results include recommendations to address household waste-borne hazards and vulnerabilities, according to waste workers involved in this research.

Water, sanitation and hygiene for homeless people.

This short communication provides insights into water, sanitation and hygiene (WASH) for homeless people through a scoping study conducted in Dhaka, Bangladesh. It investigates homeless access to WASH through the lens of a rights-based approach. It demonstrates that homeless people's denial of their right to WASH reflects their marginal position in society and an unequal distribution of power and opportunities. The study ultimately suggests a rights-based approach to work toward dealing with the root causes of discrimination and marginalisation rather than just the symptoms. For the homeless, who not only lack substantive rights, but also the means through which to claim their rights, an integrated rights-based approach to WASH offers the possibility for social inclusion and significant improvements in their life conditions. Given the unique deprivation of homelessness it is argued that in addressing the lack of access to adequate WASH for homeless people the immediate goal should be the fulfilment and protection of the right to adequate shelter.

Comparative research on phosphorus removal by pilot-scale vertical flow constructed wetlands using steel slag and modified steel slag as substrates.

This research mainly focused on the phosphorus removal performance of pilot-scale vertical flow constructed wetlands with steel slag (SS) and modified steel slag (MSS). First, bench-scale experiments were conducted to evaluate the phosphorus adsorption capacity. Results showed that the Langmuir model could better describe the adsorption characteristics of the two materials; the maximum adsorption of MSS reached 12.7 mg/g, increasing by 34% compared to SS (9.5 mg/g). Moreover, pilot-scale constructed wetlands with SS and MSS were set up outdoors. Then, the influence of hydraulic retention time (HRT) and phosphorus concentration in phosphorus removal for two wetlands were investigated. Results revealed that better performance of the two systems could be achieved with an HRT of 2 d and phosphorus concentration in the range of 3-4.5 mg/L; the system with MSS had a better removal efficiency than the one with SS in the same control operation. Finally, the study implied that MSS could be used as a promising substrate for wetlands to treat wastewater with a high phosphorus concentration. However, considering energy consumption, SS could be regarded as a better alternative for substrate when treating sewage with a low phosphorus concentration.