Assessing wastewater pollution from outdoor night markets and its impacts on river quality

Abstract

Night markets are attractive tourist sites in Asian cities. However, the outdoor activities produce different types of pollutants. Air pollution and solid waste in night markets have received much attention, but wastewater pollution from night markets has rarely been examined. The untreated wastewater are discharged into roadside gutters and might contaminate receiving waterbodies. In this study, night markets in Taipei city, Taiwan, were surveyed to clarify the characteristics of wastewater. The sampled wastewater showed high levels of organic substances, oil and grease, and phosphorous but low levels of nitrogen compounds. In addition, the unit pollution loads in night market stalls was obtained. The BOD load of each stall in the night markets was 2,509 g/day, which is higher than the sewage emissions of 50 people. In order to know the impacts of night market wastewater on receiving waterbody, a water quality model, the Water Quality Analysis Simulation Program (WASP), was used in the studied river, Keelung river. If night market wastewater could be collected (not discharged), the BOD concentration could be reduced by 9.8%, but the NH3-N and DO concentration could be reduced by less than 1%.

Operational and Environmental Assessment for Night Markets under the Informal Economy Impacts: Insights from the Case Study of Selangor, Malaysia

“…Studies revealed that informal policies developed in modern urban development as a flexible strategy favored and benefited urban development [4]. As a manifestation of the informal economy, night markets were not only convenient places to attract locals to buy goods but were also places where tourists traveled to experience local characteristics, especially in Asian cities [5]. Traditional night markets were outdoor street markets that generally operated from evening to midnight, and their informal manifestation led to their operation usually being neglected by stakeholder management [5,6,7].…”

“…As a manifestation of the informal economy, night markets were not only convenient places to attract locals to buy goods but were also places where tourists traveled to experience local characteristics, especially in Asian cities [5]. Traditional night markets were outdoor street markets that generally operated from evening to midnight, and their informal manifestation led to their operation usually being neglected by stakeholder management [5,6,7]. In addition, solid waste management is a serious issue not only for developed countries but also for developing countries due to the increasing population [8].…”

“…Night markets, as one of the dynamic economic expressions, were scattered like fireworks worldwide [9]. However, night markets operating outdoors were characterized by severe environmental impacts due to their direct contact with the environment [5], such as plastic packaging hazards [10], vendors' and visitors' views and behavior [11,12], garbage pollution and hygiene problems [13], and environmental degradation [14].…”

“…In addition, the dumping of organic wastes into the environment might contribute to global warming, and policy actions were needed to target air pollution problems at different levels of management to create synergistic effects and reduce the impact of climate change [19,20]. Existing studies involving the night market area included solid waste recycling from garbage bins [21], wastewater pollution generated [5], hazards of exhaust gases generated [18,22,23], sources of electricity for operations [6], tableware materials [24], dangers of plastic packaging for hot food [25], perceptions of using plastic packaging [26], willingness of merchants to have environmentally friendly packaging [10], and biodegradation potential of recycled wastes [27]. Sustainable development is one of the critical environmental challenges to be addressed by all parties, including governments, consumers, and producers, who need to take responsibility for the environment [28].…”