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The essential objective of this study was to estimate 222Rn, 238U, and 226Ra concentrations of plankton samples, along with the risk indices defined by PAEC, Ep, AED and CPPP. These analyzes were carried out on plankton samples from fifteen-alley air conditioner filters in the old Mosul area. In this analysis, using the cumulative monitoring technique of the PM-355 nuclear track detector. The maximum concentrations of radon, uranium, radium and risk indices were observed in Bableksh (sample 5) alley at 77.77(Bq. m−3), 3.74(ppm), 21.46(Bq.kg−1), 0.0084(mWL), 0.3465(WLMY−1), 1.962(mSv.y−1), and 35.31(per 106person). Whereas at Al Hadhira alley the minimum was found to be 39.07(Bq.m−3), 2.05(ppm), (10.78 Bq.kg−1), 0.00422(mWL), 0.1741(WLMY−1), 0.9856 (mSv.y−1), and 17.74(per106 person. The average concentrations of radon, uranium, radium and, risk indices of all studied alleys were 59.156 ± 10.7 (Bq. m−3), 2.803(ppm) ± 0.48, 16.34 ± 4.49(Bq.kg−1), 0.00646((mWL)) ± 0.00011 , 0.2662 (WLMY−1)± 0.0517 , 1.506 (mSv.y−1)± 0.279 , and 27.116 (per 106person)± 5.043 , respectively. Alpha indexes were estimated for all surveyed alleys, in addition to the radioactivity tests and the risk indices. Their values varied between 0.053 and 0.107, with an average 0.081 ± 0.0021. Such levels are significantly smaller than the total dose given by the United Nations Scientific Committee on the effects of atomic radiation, especially at Exposure to 222Rn progeny (Ep) which is within the range of 0.2–10 mSv.y−1 (UNSCEAR). Appropriate correlations between radon concentration with uranium and radium concentration (R2 = 0.8739 and 0.896) have been identified, respectively. The results revealed that the amount of background radioactivity of the alleys of old Mosul area would be within acceptable limits. [ABSTRACT FROM AUTHOR]

The radiological contamination with radium in oil and gas production is challenging environmental and health concerns. This study investigated the synthesis of zeolite NaA modified with Na 2 SO 4 (Na 2 SO 4 @zeolite NaA) hydrothermal method and subsequent use as an adsorbent along with manganese dioxide (MnO 2) for removing radium isotopes (226Ra and 228Ra) from acidic radioactive wastewater (ARW). ARW was generated through acidic sequential leaching of petroleum-based organic soils collected from the South Rumaila fields in the Basra Governorate, Iraq. The optimum adsorption parameters were MnO 2 : Na 2 SO 4 @zeolite NaA mass ratio of 1:0.5 g.g−1 and a pH of 6.3 resulting in maximum removal of 78.7% and 66.7% for 226Ra and 228Ra, respectively. Higher levels of removal were not attainable due to co-elements effect. The adsorption was endothermic with cation exchange of Na+ with Ra2+ being the main mechanism. The incorporation of Na 2 SO 4 increased the exchange sites available for Ra2+ and the surface area and pore size available for facilitating such reactions. The exhausted column was regenerated and subsequently used for five cycles with a small drop in the removal of 226Ra and 228Ra by 11% and 9.5%, respectively highlighting the propitious application of Na 2 SO 4 @zeolite NaA and MnO for treating contaminated wastewater in oil fields. [Display omitted] • Na 2 SO 4 @zeolite NaA was used with MnO 2 at 1:0.5 g/g for 226Ra and 228Ra removal. • A removal of 78.7% and 66.7% for 226Ra and 228Ra was achieved. • Higher removal levels were not attainable due to the competition of co-elements. • The adsorption was endothermic and described by the modified dose-response model. • The column was used for five cycles with a small drop in the removal of Ra nuclides. [ABSTRACT FROM AUTHOR]