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MENA wastewater treatment and reuse: what nutrient neutrality implies | |
| Nitin Konde |
Simply put, effluent is any water that has been deemed unnecessary. Waste water is water that has already been used and is being discharged from places like homes (after being used for things like bathing, washing, flushing bathrooms, etc.), farms, and factories.
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Nearly all wastewater is water, with only a tiny percentage (less than 1%) being solid refuse. As a result, wastewater has considerable potential to help alleviate the freshwater shortage in arid and semiarid areas.
To repurpose or recycle wastewater is to put it to another use after it has already been used for another purpose. Landscape irrigation, agricultural irrigation, aesthetic uses, groundwater recharge, industrial uses, and fire prevention are all examples of beneficial end uses for which reclaimed water or wastewater must be used in accordance with relevant rules.
Types of wastewater reuse can be divided into the following categories:
The majority of the Middle East and North Africa (MENA) area is classified as arid or semi-arid. Decades ago, the area exhausted its supply of renewable fresh water, meaning that it could no longer produce enough food using only the water found within its borders. There are 6% of the world's people living in the MENA area, but only 1% of the world's freshwater. The countries in the area rely on fragile, and sometimes nonrenewable, aquifers and on seasonal rainfall and a limited number of rivers, some of which carry run-off from other countries. In turn, this makes their economies far more vulnerable to changes in water extraction, transportation, and consumption than those of other areas. The water table drops, the salinity of the groundwater rises, the purity of the groundwater declines, and the environment suffers as a result of the constant over-pumping of groundwater.
Therefore, new non-conventional water resources like water desalination, wastewater, and rain gathering are required to keep up with the expanding demand. Since agriculture is the primary user of water in the area, efforts are being made to find ways to reuse wastewater for purposes such as groundwater recharge and irrigation. Per capita wastewater production is expected to be between 30 and 90 m3 per year in water-scarce regions like the Middle East and North Africa (MENA). Increases in population, urbanization, better living conditions, and economic development have all contributed to a current and future rise in the amount of wastewater from a variety of sources.
Water supply in the Middle East and North Africa
Estimates and projections of country-based populations and annual renewable water resources suggest that the majority of MENA nations will have less than 1,000m3/capita by the year 2025. Iraq, Iran, and Lebanon are the only nations in the world with annual renewable water resources of more than 1,000 m3/capita. Kuwait, Libya, Qatar, Saudi Arabia, the United Arab Emirates, and Yemen are just a few examples of nations with annual renewable water resources of less than 100m3/capita. More than half (14 out of 20) of MENA's nations faced water scarcity that year.
The Intergovernmental Panel on Climate Change found that precipitation in the MENA area would decrease by 10%-25%, runoff would decrease by 10%-40%, and evaporation would increase by 5%-25%. Furthermore, there are no potential avenues for expanding the availability of water. In addition, warmer temps will increase the rates of evaporation from surface water storage reservoirs and soil moisture loss, as well as the rates of evapotranspiration in vegetated areas, which will reduce run-off and groundwater recharge rates, and the water needs of agricultural crops.
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Middle East and North Africa water usage
In most Middle Eastern and North African nations, agriculture is the single largest user of freshwater. Crop production typically accounts for the vast majority (86%) of water withdrawals across all categories of water users. Only 6% of available water is used in manufacturing, while 8% is consumed by households.
The agricultural sector is vital to the economies of most MENA countries, though the tourism and oil industries play significant roles for some. Therefore, agricultural, domestic, and commercial water use all vary considerably. Bahrain, for instance, allocates 29% of its entire renewable water supply for agricultural use. Israel (58%), Qatar (59%), Lebanon (60%), and Jordan (65%) are also comparatively less water-hungry in agriculture than the MENA norm. Three countries use significantly more water than the others for agricultural purposes: Iran (92%), Egypt (86%), and Iraq (79%).
Treatment of wastewater in the Middle East and North Africa
In the Middle East and North Africa (MENA) region, 13.2 billion cubic metres (BCM) of wastewater is produced yearly by the residential and industrial sectors; however, only 5.7BCM (43.2% of the total) is treated. Each year, MENA countries discharge about 7.5BCM of raw sewage into the environment (roughly 57% of the total sewage produced in the area).
Almost eighty-three percent of treated wastewater is put to use in farming, while most partly treated, diluted, or untreated wastewater is put to use by urban and peri-urban farmers. Furthermore, the nations treat their wastewater in various ways. In Bahrain, for instance, all collected wastewater receives treatment via activated sludge and tertiary treatment processes, while in Iran, Lebanon, Morocco, and Libya, less than 10% of collected wastewater is treated.
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Gains for Middle Eastern and North African nations from recycling used water
Reusing effluent has many positive effects. Groundwater recharge helps regulate saltwater intrusion and reduce pollution of water supplies and delicate receiving bodies. Reusing wastewater has monetary value because it conserves freshwater supplies while also supplying a sizable quantity of extra water. The use of synthetic fertilisers is minimised and nutrient-rich water for watering is made available. The economy and society as a whole would profit from the creation of new jobs and the development of exportable goods. Wastewater reuse eliminates the danger to public health posed by mineral and organic trace substances and pathogens in wastewater by properly treating the water before its intended return.
Wastewater treatment and reuse difficulties in the Middle East and North Africa
The rate of wastewater treatment is still low in many MENA countries. Many wastewater treatment plants are poorly maintained and operate beyond the design capacity. The main challenges facing the treatment and reuse of wastewater in MENA countries are:
Inadequate information on the status of reuse and disposal of different forms of wastewater and associated environmental and health impacts: Large discrepancies exist in wastewater evaluations even when data are accessible, due to the various criteria that are applied.
Incomplete economic analysis of the wastewater treatment and reuse options: Certain wastewater treatment and reuse methods come with a price and potential payoff. However, these studies typically only consider the economic viability of a project. The degree of treatment, the ultimate reuse, and the transportation options for treated effluent are all important factors to think about.
Perceived high cost of developing wastewater collection networks and wastewater treatment plants: The infrastructure required, the quality of the wastewater collected, and the expected quality of the treated wastewater all play a role in the varying costs and availability of wastewater treatment facilities from one place to the next.
Lack of wastewater treatment and reuse cost-recovery mechanisms, including commitment to support wastewater treatment programmes: As a result, there is not as much need for reclaimed water that is priced according to its quality, as opposed to treated or untreated wastewater that is given away for free to farms. This is due to the fact that scepticism about the quality of the reclaimed water is shared by farms and homeowners. Furthermore, it is difficult to persuade farmers to pay anything for reclaimed water that is not of high quality due to the availability of free, untreated wastewater.
Preference for freshwater over wastewater: The public has a limited grasp of the environmental benefits of wastewater treatment and reuse of reclaimed water due to a lack of commitment on the part of governments to promote and support comprehensive wastewater treatment initiatives. Moreover, consumers have doubts about the purity of reclaimed water.
The mismatch between water pricing and water scarcity: The worth of water should reflect its scarcity. Particularly relevant in the farming industry. Costs associated with supplying farms with clean water are not reflected in the price charged to farmers. Households in areas of the world where water is scarce do not see the value in wastewater treatment and reuse because it is gathered outside of the cities. Therefore, governments can more easily recoup costs associated with sewer connection and service than the more lengthy process of treating the wastewater itself.
Overall inefficient irrigation and water management schemes, which undermine the potential of water reuse: The potential of reclaimed water as a resource for irrigation, environmental conservation, groundwater recharge, municipal, recreational, and industrial uses is often overlooked in management plans.