Hi,

The use of treated wastewater for the irrigation of agricultural soils is an alternative to utilizing better-quality water, especially in semiarid regions where water shortage is a very serious problem. For this reason, it is necessary to know precisely the composition of water before applying it to the soil in order to guarantee minimal impact in terms of contamination and salinization.

Few important research in this area are:

Article Effects of long-term irrigation with treated wastewater. Par...

Effect of irrigation with treated wastewater on soil chemical...

I hope you may get some help.

Thanks

Ankur

The use wast water for irrigation in Agricultural increasing salinity in soil

It enhances sodium and chloride concentration in the soil. The average salinity enhancement if irrigated for long period ranged from 2.5 to 3.69 dS m−1 with an average of 2.8 dS m−1. There was an increase in organic matter content ranging from 17% to 30% in sewage-irrigated soil samples as compared to well water-irrigated ones. It generally helps to lower the soil pH but accumulation of suspended solids may reduce the infiltration rate.

I agree with Ankur Srivastava answer. Increase in salinity may reduce the growth of the vegetation but that may not be the main consequence of using treated wastewater for irrigation purpose. The main consequence is the possibility of plants and vegetable uptaking heavy metals such as Pb, Cd, Zn, As, Se and Co which may contain in the wastewater. Some of these metal are present in wastewater, even though in lower concentrations. On the other hand, some natural and engineered nanoparticle used in wastewater remediation are made of the metals, thus there is high chance that these metals remain in the treated wastewater. Thus, it is very important to ascertain the composition of the treated wastewater before using it for irrigation or any other alternative usage, in order to avoid the risk of heavy metals and toxic anions on human and animal health.

It depend of presence of salt in treated waste water and salts being taken by plants.

Believing that the main problem is that the water from the treated effluents will be evaporated or infiltrated into the soil and then the concentration of nutrients that it captures in the soil may start to occupy its micropores and increase the surface sealing of the soil. Thus, if irrigation is carried out for a long time without soil movement techniques, it can become impoverished due to compaction and less water infiltration.

Salinity of waste water may be reduced by membrane filtration procedure.

I agree with Ankur Srivastava

I agree with Ankur Srivastava ,

and I would like to add a European Regulation.

Regulation applies whenever treated urban waste water is reused, for agricultural irrigation as specified in Section 1 of Annex I to the Regulation (attached)

I think firstly I would like to see the composition of treated wastewater. How do you know that treated wastewater has high salinity in general case scenario? It might not be a problem.

Then it depends on the salt type, some salts definitely affect plants but there are others which are salt tolerant (halophytes). So you have to check the plant phsyiology aspects too.

The acidic nature of treated waste water can be neutralized by adding coal fly ash having basic nature.