The Presence and Distribution of Radioactivity and Radionuclides in Kuwait Wastewater Treatment Plants

Public interest in radioactivity and radionuclides distribution in the environment has increased significantly due to their toxicity, health effects, and related environmental impacts. One of the concerns for wastewater treatment and reclamation is the presence and distribution of contaminants that are not removed by the wastewater treatment plant in case its effluent is reused, particularly, for irrigation or direct potable reclamation. Radionuclides are contaminants that are not effectively removed by wastewater treatment plants. To address radionuclides in wastewater treatment plants of Kuwait, a survey was planned and conducted in five wastewater treatment plants to investigate the presence and distribution of radioactivity in wastewater. The results of gamma, alpha, and beta surveys indicated that the wastewater treatment plants investigated showed normal level of radioactivity concentrations that were below the International Atomic Energy Agency (IAEA) recommended limits for unrestricted use of the treated wastewater. It was found that radionuclides had different fates in treatment plants. Radionuclides like 40K, total 210Pb, 137Cs, 226Ra, 228Ra, 238U, and 235U would likely partition onto sludge and biosolids than be discharged in the liquid effluents. In contrast, 131I would more likely remain in the liquid effluent than partition onto the sludge. Its short half-life of 8 days would, however, mean that it would have limited effects even if the treated wastewater is widely used. Storage to segregate these radionuclides may not be feasible because it will require long periods due to the long half-lives of some of them (e.g., half-life of 137Cs is 30.7 years).