To cope with water crisis, wastewater reuse has been introduced as a potential source for irrigation. On the other hand, irrigation with wastewater may negatively affect the surroundings. In this study, reed plant (Phragmits australis) and its biochar were tested as low-cost treatments to enhance the efficiency of wastewater reclamation in wetlands within only 72 h. The investigated water was of low irrigation quality and exhibited high contents of BOD5 and fecal coliform. Moreover, this water contained high levels of soluble cations and anions; besides, being marginally contaminated with Cu, Mn and Cd. After 2 days in the sedimentation unit, wastewater was subjected to three reclamation treatments in parallel (each lasted for 24 h): (1) a “sand & gravel bed”, (2) “reed plants grown on a sand & gravel bed” and (3) “biochar + a sand & gravel bed”. The results showed that all treatments decreased BOD5, fecal coliform, total cations and anions, with superiority for the second and third treatments. The levels of the potentially toxic elements also decreased to values within the permissible levels. Although the aforementioned wastewater treatment processes upgraded the quality of this water, it remained in the poor grade. Biochar or reed plants grown on sand and gravel beds significantly improved wastewater quality to the medium quality grade, with superiority for biochar treatment. In conclusion, investigated treatments are guaranteed in wetlands for wastewater reclamation; yet, further protocols should be followed to achieve safe handling of this water and attain the sustainable goals.

The conventional treatment techniques are efficient in wastewater treatment but their construction and operation costs are high. Natural treatment such as offstream and in-stream wetlands proved to be effective, feasible and require low operation/maintenance costs, and no trained labor or added chemicals are required. These techniques have been applied in Egypt at a pilot scale. Lake Manzala Engineered Wetland (LMEW) on Bahr El-Baqar drain and Passive Instream Wetland (PIW) in Faraa El-Bahwo drain are some of these projects. The objective of this study is to investigate the technical applicability of those two natural treatment techniques in the Nile Delta and assess the suitability of the treated effluent for reuse in agriculture. Both systems were visited to evaluate physical characteristics and design elements of each treatment system. Water samples were collected at different stages of each treatment system. The collected samples were analyzed for the Fecal Coliform (FC), Biological Oxygen Demand (BOD), Total Phosphorus (TP) and Total Suspended Solids (TSS). Monitoring results of LMEW showed that the overall treatment efficiency varies depending on the type and behavior of each pollutant. The removal efficiency in LMEW was as high as 98% for FC and as low as 57% for BOD. For PIW, the results showed that the overall treatment efficiency varies from 97.5% for FC to 38% for TP. For both treatment systems, the results show the possibility of reusing the treated water in irrigation according to the local regulations.

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