Impact of Wastewater on Surface Water Quality in Developing Countries: A Case Study of South Africa

Abstract

Wastewater effluents are major contributors to a variety of water pollution problems. Most cities of developing countries generate on the average 30-70 mm 3 of wastewater per person per year. Owing to lack of or improper wastewater treatment facilities, wastewater and its effluents are often discharged into surface water sources, which are receptacles for domestic and industrial wastes, resulting to pollution. The poor quality of wastewater effluents is responsible for the degradation of the receiving surface water body. Wastewater effluent should be treated efficiently to avert adverse health risk of the user of surface water resources and the aquatic ecosystem. The release of raw and improperly treated wastewater onto water courses has both short-and long-term effects on the environment and human health. Hence, there should be proper enforcement of water and environmental laws to protect the health of inhabitants of both rural and urban communities. This study reports major factors responsible for the failing state of wastewater treatment facilities in developing countries, which includes poor operational state of wastewater infrastructure, design weaknesses, lack of expertise, corruption, insufficient funds allocated for wastewater treatment, overloaded capacities of existing facilities, and inefficient monitoring for compliance, among others.

Ecological and Public Health Implications of the Discharge of Multidrug-Resistant Bacteria and Physicochemical Contaminants from Treated Wastewater Effluents in the Eastern Cape, South Africa

“…Poor management and maintenance (i.e., inefficient operational, poor design, lack of expertise, inefficient monitoring and poor documentation of compliance, among others) of many existing wastewater treatment facilities remains a concern and often leads to the discharge of poorly treated effluents into the aquatic environments in most developing countries, such as South Africa, with its attendant ecological and public health risks [27,28]. This study is therefore designed to assess the physicochemical qualities and the prevalence of FIB (E. coli) and Vibrio species in the discharged effluents of two wastewater treatment plants in Eastern Cape, South Africa, with particular interest in the release of multidrug-resistant Vibrios species into the aquatic environment, and their associated ecological and public health implications.…”

Atoyac River Pollution in the Metropolitan Area of Puebla, México

“…According to Huang et al [44], the dissolved oxygen decrease in urban rivers is rising in developing countries, which causes strong stresses in aquatic ecosystems. This decrease is due to the bacterial decomposition process in the presence of a large number of organic compounds [39,42,45]. In the case of the Atoyac River, these come mainly from the discharges of the three municipal treatment macro-plants (El Conde, San Francisco, and Atoyac Sur), and effluents of hundreds of different industries (automotive, pharmaco-chemistry, metalworking, food, paint, and so on) that do not have efficient purification systems [20,21].…”

“…This represents a public health threat due to the fact that these water resources are used to irrigate crops. This suggests that the typical self-cleaning process of these ecosystems (dilution and assimilation) does not occur, possibly due to the amount of residual effluents that are discharged along the river exceeding the natural buffering capacity of the aquatic ecosystem [45,55], such that the oxygen concentration in the water remains low, independently of the area of the river or season.…”

Performance of Anaerobic Baffled Reactor for Decentralized Wastewater Treatment in Urban Malang, Indonesia

“…Indonesia is the fourth most populous country in the world with a population of approximately 263 million people in 2017 and a population density of 146 habitants/km 2 . Over 50% of the total Indonesian population lives on Java Island, which is the most populated island in Indonesia with 940 habitants/km 2 [1]. The majority of the population in Java Island live in cities, which has a detrimental impact on public health and environmental quality due to the limited capacity to provide water and sanitation services at a pace to match urban population growth.…”

“…A growing population will demand services like water supply, which in return contributes to increasing wastewater discharges into an already under developed sanitation infrastructure. In addition, untreated wastewater discharges add pressure to environmental ecosystems, particularly surface water and groundwater resources [2].…”