The importance of wastewater treatment plants to implement the afforestation program

The afforestation program in Saudi Arabia is one of the important programs in which we have come a long way. 41 million trees have been planted in the past two years. The Saudi Green Initiative aims to plant 10 billion trees and as the steady increase in the amount of water used and wastewater produced by various communities and industries. The importance of wastewater treatment plants and their use in irrigation and afforestation has become apparent. Therefore, we at CareWater work to provide the best types of wastewater treatment plants. Do not hesitate to request a quote. We will be happy to help you at any time.

Definition of wastewater

Sewage refers to the liquid waste discharged from homes, commercial buildings, and factories to individual disposal systems or to municipal sewage pipes.

History of wastewater treatment

The use of wastewater for irrigation may date back to the earliest times of human cultivation. However, the use of wastewater on a large scale and under control for irrigation. The history of wastewater treatment dates back to the last century when the so-called sewage farms were established. This was done in parts of Europe, Australia, India, and the United States to dispose of sewage and prevent river pollution. Although crops were produced on these farms, crop production was a secondary consideration. There are also examples of farms where tree plantations were irrigated with sewage.

In some cases, “sewage farms” refer to sewage treatment plants, but the common usage of the term refers to a farm established to dispose of sewage by irrigating crops and sometimes trees.

During this century, and especially during the past two decades, the practice of irrigating crops with municipal sewage has become more widespread. This is especially true in arid and semi-arid regions of both developed and developing countries. The controlled use of treated and untreated sewage in irrigation is now very common in Europe, the United States, and elsewhere. In China, for example, more than 1.33 million hectares, mostly agricultural land, are irrigated with sewage. The wastewater scheme in Mexico City is the largest in the world (90,000 hectares of irrigated land). It is used throughout the country in most cities with a sewer system.

A number of schemes have been launched to use wastewater for irrigation of crops and landscapes (parks, roadsides, school grounds, golf courses, etc.) in the Near East and parts of North Africa, as a means of effectively disposing of wastewater and conserving and recycling water.

Benefits of urban afforestation

The planting of trees in and around urban areas for environmental protection, recreation, and leisure purposes is increasingly recognized. Although all cities benefit from trees in the urban landscape, the benefits are perhaps most pronounced in arid and semi-arid tropical regions. Where natural vegetation is scarce and needs protection from sandstorms and drying winds. And where high temperatures make shade a matter of health as much as comfort.

In these areas, tree planting requires irrigation at least during the establishment phase, if not throughout the life of the trees. Cities that wish to increase forest plantations, greenbelts, or recreational trees in and around urban areas but cannot justify using scarce freshwater resources for irrigation may be able to use wastewater for this purpose. Irrigation of large forest plantations, greenbelts, and urban green spaces can make a significant contribution to the goal of safe waste disposal and treatment. Because small or scattered trees require relatively limited amounts of water. Their primary benefits will come from the other environmental services they can provide (pollution mitigation, noise, shade, and beautification) rather than from wastewater disposal.

Benefits of using wastewater for irrigation

There are many potential benefits to using municipal wastewater for irrigation, including safe and cost-effective wastewater treatment and disposal; water conservation, and groundwater recharge. And the use of nutrients in wastewater for productive purposes. Irrigation of trees may provide additional benefits. In areas where water is relatively abundant, irrigation of crops or forests may be primarily for treatment and disposal purposes. In arid and semi-arid regions, groundwater recharge and tree and crop production issues may be as important or more important.

Safe and Low-Cost Treatment and Disposal

If inadequately treated or improperly disposed of, wastewater is a source of pollution and a health hazard. However, the cost of treatment using conventional methods is high and is prohibitively expensive for most developing countries. As a result, countries are experimenting with other forms of treatment, including land application methods, and irrigation. When done correctly, they are simple, low-cost, and effective means of disposing wastewater and improving its quality. Once wastewater has already been treated, this practice can improve its quality at a low cost. When limited primary treatment is available, it may provide a means of disposal that poses less risk of disease and environmental damage. Irrigating trees is likely to pose fewer health risks and is more socially acceptable than irrigating crops.

Wastewater Treatment

Conventional water treatment methods are described here in order In terms of intensity (and cost):

Primary treatment

This is a simple sedimentation process in which organic and inorganic solids are allowed to settle out and thus removed from the water. This reduces the biological oxygen demand by 25 to 50 percent. The total suspended solids by 50 to 70 percent, and the oil and grease content by 55 to 65 percent. Some organic nitrogen, phosphorus, and heavy metals are also removed. The primary waste may be of acceptable quality for irrigation of trees, orchards, vineyards, fodder crops, and some processed food crops.

Secondary treatment

The most common level of treatment in industrialized countries, this method consists of additional treatment (after primary treatment). To remove the remaining organic matter and suspended solids using biological processes (i.e. metabolism by aerobic microorganisms, especially bacteria). Secondary treatment is required when the risk of public exposure to the wastewater is high.

Tertiary treatment

This is a more complex and expensive process, which removes certain components of the waste feeders such as nitrogen, phosphorus, additional suspended solids, heavy metals, and dissolved solids. When public exposure to waste is high (e.g. when sprinkler irrigation is used in public parks and golf courses). The tertiary treatment is carried out to reduce the risk of disease. When irrigation with treated wastewater is intended, the removal of plant nutrients during the treatment process is a disadvantage in terms of plant productivity.

Disinfection

This is often done after secondary or tertiary treatment to kill viruses and other pathogens that may remain in the water. This process consists of adding a chemical (usually chlorine) to the water.

A number of non-conventional methods of wastewater purification are being adopted in many countries. As alternatives or supplements to conventional treatment. These include natural biological treatment systems such as stabilization ponds and land treatment, including irrigation. These methods tend to be less expensive and easier to operate and maintain. But are effective in purifying other chemical components of nutrients and pathogens.

In some places, land treatment is used to purify wastewater. In other places, it is used to upgrade primary, secondary, or tertiary wastewater. Irrigating crops or trees with wastewater is particularly attractive in the face of increasing water demands and rising costs of synthetic fertilizers. It represents a means of conserving water and nutrients and using them for productive purposes. Irrigation and other land application methods require much more land than conventional treatment. So lack of available or affordable land may be a constraint in some urban and peri-urban areas.