Propose canal diversion surface flow constructed wetland for drainage water treatment: a Tala drain Egypt's Nile Delta

Abstract This study proposed a canal diversion surface flow constructed wetland (CWT) to treat the drainage water in the Tala Drain Gharbia Governorate where the Nile Rosetta Branch is its outfall. The treated water will be used for irrigation purposes. The proposed treatment system consists of a sedimentation pond, a CWT with reed plants, and a treated water storage pond. Field data on hydraulic, climatic, and influent concentrations were collected. The first order of P-K-C* relaxed tanks was applied to design the CWT. The results indicated that for a 2400 m 3 /d design discharge, a BOD sedimentation pond of a surface area of 2600 m 2 (260 m long and 10 m broad) is required for one-day hydraulic retention and 1.0 m water depth. The CWT area is controlled by the winter BOD indicated four parallel CWTs each one of a surface of 12,480 m 2 , hydraulic loading rate of 0.05 m/d, and a hydraulic retention period (HT) of 2.76 days. The CWT water balance indicates that minimum and maximum water losses of 3 and 14%, respectively, recorded in January and June and the minimum and maximum operation discharge are 2482 and 2741m 3 /d, respectively. The rates of elimination of BOD, TN, TP, and FC showed 62, 58.4, 43, and 99.8%, respectively indicating good water quality for irrigation uses. The treated drainage water is still far from the drinking water standards and needs purification. The proposed green wastewater treatment system in the study region and similar regions will help decision-makers as a primary strategic water resource management and ecological solution to meet the United Nations' Water Sustainable Development Goals.