Table 2 Comparison of effectiveness of bare NZVI, CS, CS-CMβ-CD and CS-NZVI-CMβ-CD beads for the removal of metal ions.

Activated carbon was synthesized from coconut shells. The Brunauer, Emmett and Teller surface area of the synthesized activated carbon was found to be 1640 m 2 /g with a pore volume of 1.032 cm 3 /g. The average pore diameter of the activated carbon was found to be 2.52 nm. By applying the size-strain plot method to the X-ray diffraction data, the crystallite size and the crystal strain was determined to be 42.46 nm and 0.000489897, respectively, which indicate a perfect crystallite structure. The field emission scanning electron microscopy image showed the presence of well-developed pores on the surface of the activated carbon. The presence of important functional groups was shown by the Fourier transform infrared spectroscopy spectrum. The adsorption of methyl orange onto the activated carbon reached 100% after 12 min. Kinetic analysis indicated that the adsorption of methyl orange solution by the activated carbon followed a pseudo-second-order kinetic mechanism (R 2 > 0.995). Therefore, the results show that the produced activated carbon can be used as a proper adsorbent for dye containing effluents.

Arsenic (As) and cadmium (Cd) are noxious and carcinogenic pollutants that can be removed from water by using emerging, ecofriendly, phytofiltration technology that employs Micranthemum umbrosum. After culturing M. umbrosum for 7 days in a hydroponic experiment, accumulation of 1219±44.11 µg As g -1 and 799.40±30.95 µg Cd g -1 were observed in the leaves, from 1000 µg As L -1 and 1000 µg Cd L -1 of water, respectively. Plant and water samples were analyzed for assessing the As and Cd accumulations, translocations, phytotoxic effects, uptake mechanisms and kinetics, and for evaluating the potential of M. umbrosum in As and Cd phytofiltration. The uptake pattern was leaf > stem > root for both pollutants. The plant showed higher resistance toAs than to that to Cd. Uptake of inorganic As species was much greater than that of organic As and was found at above the substrate concentration. However, Cd showed similar uptake pattern to that of inorganic As species, and the data was better fit to a non-linear than a linear model. Low molecular weight substances that have thiol group(s) may be responsible for the binding of As in plants whereas Cd showed a different mechanism to that of As. M. umbrosum showed good As phytofiltration capabilities without any phytotoxic effects, but it was found to be a moderate accumulator of Cd with some phytotoxic effect compare to some other previously studied plant.

No abstract

This study explores the associations of drinking rainwater with mineral intake and cardiometabolic health in the Bangladeshi population. We pooled 10030 person-visit data on drinking water sources, blood pressure (BP) and 24-h urine minerals. Fasting blood glucose (FBG) was measured in 3724 person-visits, and lipids in 1118 person-visits. We measured concentrations of sodium (Na), potassium (K), calcium (Ca) and magnesium (Mg) in 253 rainwater, 935 groundwater and 130 pond water samples. We used multilevel linear or gamma regression models with participant-, household-and community-level random intercepts to estimate the associations of rainwater consumption with urine minerals and cardiometabolic biomarkers. Rainwater samples had the lowest concentrations of Na, K, Ca and Mg. Rainwater drinkers had lower urine minerals than coastal groundwater drinkers: −13.42 (95% CI: −18.27, −8.57) mmol Na/24 h, −2.00 (95% CI: −3.16, −0.85) mmol K/24 h and −0.57 (95% CI: −1.02, −0.16) mmol Mg/24 h. The ratio of median 24-hour urinary Ca for rainwater versus coastal groundwater drinkers was 0.72 (95% CI: 0.64, 0.80). Rainwater drinkers had 2.15 (95% CI: 1.02, 3.27) mm Hg higher systolic BP, 1.82 (95% CI: 1.19, 2.54) mm Hg higher diastolic BP, 0.59 (95% CI: 0.17, 1.01) mmol/L higher FBG and −2.02 (95% CI: −5.85, 0.81) mg/dl change in high-density lipoprotein cholesterol compared with the coastal groundwater drinkers. Drinking rainwater was associated with worse cardiometabolic health measures, which may be due to the lower intake of salubrious Ca, Mg and K.npj Clean Water (2020) 3:20 ; https://doi.