Suchergebnisse

Abstract
Nowadays the use of conventional wastewater treatment methods is becoming increasingly challenging mainly due to the presence of organic matter in wastewater. Therefore, an emerging technology is needed to deal with these highly concentrated and toxic non-biodegradable organic matters. In the last few decades, advanced oxidation process (AOP) has emerged to treat wastewaters discharged from industries. Recently, researchers have shown interest to use the application of ultrasound (US) in photocatalysis, i.e. sonophotocatalysis, to improve the performance of the treatment process in the degradation of organic and inorganic contaminants in aqueous streams. Sonophotocatalysis is the combination of the use of ultraviolet (UV) and US.

AbstractFood waste generation and disposal have led to several environmental problems, especially in developing countries. This phenomenon is partly because most cities rapidly urbanize, which results in population increase, urban settlement and waste generation. Improper management of waste has continued to create environmental problems. These problems have indeed interfered with the inadequate measures in managing other organic waste such as food waste. Food waste can be fermented and used for pathogen inactivation in fecal sludge (FS). The continual decrease in global crop production due to soil erosion, nutrient runoff and loss of organic matter has generated interest in using FS for soil amendment. However, due to the high number of pathogens in FS that are harmful to humans, FS must be treated before being used in agriculture. Thus, given the high amounts of food waste generated globally and the lactic acid potential of fermented food waste, several researchers have recently proposed the use of fermented food waste to suppress pathogens in FS. This review presents the various approaches in pathogen inactivation in FS using different types of food waste. On the basis of the literature review, the major problems associated with the generation, collection and application of food waste in pathogen inactivation in FS are discussed. Moreover, the trends and challenges that concern the applicability of each method are critically reviewed.

The biogas project for domestic sewage treatment (BPDST) is considered a promising facility for wastewater management in rural areas of China. This paper explores previous experimental works, cost analysis, and BPDST structure and design based on Chinese literature. Opportunities for developing decentralized or neighborhood-based BPDSTs include fulfilling Millennium Development Goals (MDGs) and Sustainable Development Goals (SDGs), the water pollution situation and deficiency of wastewater treatment facilities, the advantages of BPDSTs compared with centralized sewage plant, government support and policy drive for rural wastewater treatment, and reuse demand for resources. Meanwhile, challenges faced are emphasized as follows: uncertain responsibility for BPDSTs under different governmental departments restricts BPDST development and should be specified; uncertain effluent quality due to low efficiency of nutrient removal requires aerobic post-treatment to some extent; rural environmental awareness is still low and should be heightened; more funds should be invested in R&D for improvement of technology innovation; more reuse and resource recovery elements should be considered during implementation; follow-up services are lacking and should be improved; and BPDST maintenance should be trained. This paper could provide valuable reference for other developing countries.

AbstractDue to world population growth, global climate change and the deteriorated quality of water, water supply struggles to keep up the clean water demand to meet human needs. Ultraviolet (UV) technology holds a great potential in advancing water and wastewater treatment to improve the efficiency of safe treatment. Over the last 20 years, the UV light disinfection industry has shown a tremendous growth. Therefore, reuse of wastewater contributes significantly to an efficient and sustainable water usage. Disinfection is a requirement for wastewater reuse due to the presence of a swarm of pathogens (e.g. bacteria, viruses, worms and protozoa) in secondary effluents. UV technology is widely favoured due to its environmentally friendly, chemical-free ability to provide high-log reductions of all known microorganisms, including chlorine-resistant strains such as Cryptosporidium. The UV disinfection process does not create disinfection by-products and unlike the chlorine UV disinfection process, it is not reliant on water temperature and pH. UV disinfection can eliminate the need to generate, handle, transport or store toxic/hazardous or corrosive chemicals and requires less space than other methods. As UV does not leave any residual effect that can be harmful to humans or aquatic life, it is safer for plant operators.

Abstract
This paper reviews the current issues that involve environmental changes in Nigeria and environmental threats within the country. The fundamental aim of scientific knowledge in environmental studies is to reconcile climate change and environmental sustainability with developmental goals. Therefore, information on impact adaptation to climate change and vulnerability research is required to develop specific, action-oriented, interdisciplinary, successful, sociopolitical and democratic reform for the entire population of a country. This condition requires large inclusion of environmental researchers, institutions, re-inventing of research structures and ideas to dominate the global environmental change research and the critical analysis of present decision making, power, structure and related information structures. This review presents the effect of climate change in Nigeria and encourages adaptation research with challenging innovation, such as the use of energy-efficient renewable energy sources to significantly reduce greenhouse gas emissions. This paper also highlighted the need for researchers to become detailed, action oriented and multiscalar and to attend communications structure problems in enhancing the environmental activity.

The ongoing Toilet Revolution in China offers an opportunity to improve sanitation in rural areas by introducing new approaches, such as urine source separation, that can contribute to achieving SDG6. However, few studies have systematically assessed the social acceptability of managing human excreta collected in new sanitation systems. Therefore, in this study we performed face-to-face interviews with 414 local residents from 13 villages across three provinces in western China, to analyze the current situation and attitudes to possible changes in the rural sanitation service chain. We found that the sanitation chain was predominantly pit latrine-based, with 86.2% of households surveyed collecting their excreta in a simple pit, 82% manually emptying their pits, and 80.2% reusing excreta in agriculture without adequate pre-treatment. A majority (72%) of the households had a generally positive attitude to production of human excreta-derived fertilizer, but only 24% agreed that urine and feces should be collected separately. Multivariate logistic regression indicated that three factors (level of education, number of permanent household residents, perceived social acceptability) significantly influenced respondents' attitudes to reuse of excreta, although only perceived social acceptability had a high strength of association. Overall, our survey revealed that rural households often misuse toilet systems, fail to comply with government-specified sanitation guidelines, have low awareness of alternative solutions, and are over-reliant on the government to fix problems in the service chain. Thus while new sanitation technologies should be developed and implemented, information campaigns that encourage rural households to manage their excreta safely are also important.

The ongoing Toilet Revolution in China offers an opportunity to improve sanitation in rural areas by introducing new approaches, such as urine source separation, that can contribute to achieving SDG6. However, few studies have systematically assessed the social acceptability of managing human excreta collected in new sanitation systems. Therefore, in this study we performed face-to-face interviews with 414 local residents from 13 villages across three provinces in western China, to analyze the current situation and attitudes to possible changes in the rural sanitation service chain. We found that the sanitation chain was predominantly pit latrine-based, with 86.2% of households surveyed collecting their excreta in a simple pit, 82% manually emptying their pits, and 80.2% reusing excreta in agriculture without adequate pre-treatment. A majority (72%) of the households had a generally positive attitude to production of human excreta-derived fertilizer, but only 24% agreed that urine and feces should be collected separately. Multivariate logistic regression indicated that three factors (level of education, number of permanent household residents, perceived social acceptability) significantly influ-enced respondents' attitudes to reuse of excreta, although only perceived social acceptability had a high strength of association. Overall, our survey revealed that rural households often misuse toilet systems, fail to comply with government-specified sanitation guidelines, have low awareness of alternative solutions, and are over-reliant on the government to fix problems in the service chain. Thus while new sanitation technologies should be developed and implemented, information campaigns that encourage rural households to manage their excreta safely are also important. (c) 2021 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http:// creativecommons.org/licenses/by-nc-nd/4.0/).

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 ...