Use of (partially) treated municipal wastewater in irrigated agriculture; potentials and constraints for sub-Saharan Africa

Abstract

This review identifies the potentials and constraints of using (partially) treated or blended wastewater for irrigation in order to assess the potentials in the context of cities in sub-Saharan Africa, specifically Maputo, the capital of Mozambique. Less than 5% of the wastewater produced in the region is being treated. Nonetheless, untreated, partially treated, and/or blended wastewater is extensively being used for agricultural purposes. Despite the last updated WHO 2006 guidelines for 'wastewater use in agriculture', authorities only consider the different water quality parameters at the point of use. Other aspects such as irrigation type, crop management and post harvesting practices, which clearly influence the contaminant log reduction, are simply ignored. Those parameters, however, are considered alternatives to a classic contaminant log reduction, which may be very beneficial for developing countries. In a more holistic approach, trade-off is favoured between the required water quality for irrigation, use of affordable treatment technologies, and adequate post-harvest strategies to reduce the current health risks to acceptable levels. Such a trade-off makes use of multiple barrier approach, whereby wastewater treatment and critical point barriers throughout the supply chain are combined. Thus, there is a long way ahead to achieve proper water reclamation for productive use; the current paradigm has to change. Current restrictive guidelines are unrealistic given current practices, and approaches more appropriate to the location's situation still need to be developed. A multiple barrier approach in combination with master planning is recommended to consider wastewater treatment and critical point barriers throughout the supply chain.

Effect of irrigation with treated wastewater on bermudagrass (Cynodon dactylon (L.) Pers.) production and soil characteristics and estimation of plant nutritional input

“…Climate change has also contributed to creating long periods of water shortage in agricultural areas, emphasizing the need to better manage water resources. In this context, non-conventional water resources generated by specialized processes, such as salt water desalination or wastewater (WW), provide an ideal source of water for irrigation in agriculture [8][9][10][11]. For a series of reasons, treated wastewater (TWW), in particular, is an attractive form of sustainable water management for irrigation purposes.…”

Contribution of Illicit Drug Use to Pharmaceutical Load in the Environment: A Focus on Sub‐Saharan Africa

“…At the start of rapid urbanization in the 1980s, China experienced major pollution due to a big amount of sewage being immediately released into rivers; the same was true in most other developing countries [ 129 ]. So far, most African governments, mostly in sub-Saharan Africa, have not restricted sewage discharge straight into urban rivers and other environmental compartments [ 100 – 102 ]. In the sewage based on the design of sewage treatment, there is the possibility of further transformation of these substances, possibly into more toxic by-products.…”

Urban Wastewater Treatment in African Countries: Evidence from the Hydroaid Initiative

“…Wastewater and sludge reuse are promising options to alleviate water shortage challenges, but their feasibility must be carefully assessed to avoid human health issues. Restrictions and guidance need to be provided for the reuse of the wastewater or sludge that has been removed from the process [52,53].…”