Fluoride removal efficiency of Tulsi (Ocimum Sanctum) from water

Fluoride concentration in drinking water higher than recommended value imposes different health problems and there are advanced and chemical based defluoridation techniques even if they are not feasible for developing countries and have limitations. Due to this, defluoridation by using locally available plants is one of the most efficient and sustainable options. Therefore, the current study was intended to investigate fluoride removal efficiency of Tulsi (Ocimum Sanctum) from water that can be an alternative means to reduce the problem related to its high concentration. A laboratory based experimental study was implemented by using potentiometric determination in Haramaya University. The leaves of Tulsi were collected, washed with tap water, rinsed with distilled water, and then were dried at room temperature, crushed and sieved through 500-μm stain-less steel sieve. The experiments were conducted on artificially fluoridated water by anhydrous fluoride and natural water samples collected from deep well water sources from Adama and Harar town. Data was analyzed using Design of Expert (DOE) and Microsoft excel. Twenty-nine runs for aqueous solution were conducted at different factor combinations and the optimum combinations were applied for natural water samples. The study depicts that plant has an efficiency of removing 68.4% of fluoride from water. The best factor combinations to achieve this efficiency was 0.2 g/100 ml, 22.6 min, 5.7 and 6.6 mg/l, adsorbent dose, contact time, pH and initial concentration respectively. pH and initial concentration have a negative effect and adsorbent dose and contact time have a positive effect on removing fluoride from water. Hence, people living in fluorosis endemic areas can use the processed plant as a de-fluoridating agent to minimize adverse health effects. HIGHLIGHT This research articles paves way to further study to remove contaminants from water, wastewater, which can pose a substantial effect on public health. The study conducted to investigate removal mechanism of fluoride from drinking water with low cost locally available plant and the software technologies were applied to find the optimum conditions at which the adsorbent works best.

New Strategies for the Simple and Sensitive Voltammetric Direct Quantification of Se(IV) in Environmental Waters Employing Bismuth Film Modified Glassy Carbon Electrode and Amberlite Resin

An analytical procedure regarding the determination of selenium(IV) by anodic stripping voltammetry exploiting the in situ plated bismuth film electrode is described. Since organics are commonly present in untreated natural water samples, the use of Amberlite XAD-7 resin turns out to be quite important to avoid problems such as the adsorption of these compounds on the working electrode. The optimum circumstances for the detection of selenium in water using differential pulse voltammetry techniques were found to be as follows: 0.1 mol L−1 acetic acid, 1.9 × 10−5 mol L−1 Bi(III), 0.1 g Amberlite XAD-7 resin, and successive potentials of −1.6 V for 5 s and −0.4 V for 60 s, during which the in situ formation of the bismuth film on glassy carbon and the accumulation of selenium took place. The current of the anodic peak varies linearly with the selenium concentration ranging from 3 × 10−9 mol L−1 to 3 × 10−6 mol L−1 (r = 0.9995), with a detection limit of 8 × 10−10 mol L−1. The proposed procedure was used for Se(IV) determination in certified reference materials and natural water samples, and acceptable results and recoveries were obtained.

Fluorophores in surface freshwaters: Importance, likely structures, and possible impacts of climate change

Fluorescence spectroscopy is one of the most useful techniques that are currently available for the characterisation of organic matter in natural water samples, because it combines easy availability of instrumentation,...