Mentha is the most common plant species grown in Saudi Arabia's Madinah city. Locally, the two popular types of mint are commercially called (Hasawi or Habaq) and (Mograbi). Both species are used in herbal teas, alone or as spice mixtures for many foods to offer aroma and flavour. In this research Hasawi mint samples were collected from three different locations and digested by two methods (acid digestion method and a microwave digestion system). Then, they were analysed for their metal contents by ICP-MS. The results from both digestion methods revealed that the following 10 metals were presented: V, Cr, Mn, Co, Ni, Cu, Zn, As, Cd and Pb. The microwave digestion system was the best for all studied heavy metals in term of sample preparation procedures, linearity (≥ 0.999), recovery (97%-101%, n=2) and precision (R.S.D% ≈ 1-2 %, n=2). Mint samples from first location contained 7 metals within the permissible limit while the remaining three metals (Cr, Cu and Zn) had higher levels. The second location contained 9 metals within the permissible limit but only one metal (Cu) had a higher level. The third location contained 6 metals within the permissible limit while it had 4 metals (Cr, Ni, Cu, Cd) with higher level. All locations contained As, Cd and Pb within permissible limit except the third location which had a cadmium amount of (0.6 mg/kg) while the cadmium permissible level is (0.3 mg/kg). Some farmers use composts (from inorganic sources), fertilizers and plant nutrients in relatively large amounts that are rich in some metals and this might explain some of the higher value of metals in the mint. Moreover, contamination from industrial activities nearby mint farms might also be expected.

UV-Vis spectrophotometer was used to determine chlorpropham (CIPC) concentration in aqueous solution. The method was validated in term of linearity, precision and limit of detection and limit of quantitation. The correlation coefficient of standards calibration curve of (1.0–10.0 µg/mL CIPC) was R2 = 1 with a precision (RSD%, n=10) ranged from (0.87–0.53%). The limit of detection (LOD) and limit of quantitation (LOQ) based on the regression statistics of the calibration curve data of (1.0–10.0 µg/mL CIPC) were 0.04 µg/mL and 0.11 µg/mL respectively. The activated carbon adsorbent was found to be effective for the removal approximately 80% of CIPC from aqueous solution. Several isotherm models (Langmuir, Freundlich, Tempkin and Dubinin–Radushkevich) were evaluated. The maximum monolayer sorption capacity (Qm) from the Langmuir isotherm model was determined to be (44316.92 µg/g). The separation factor (RL) is 0.11 which indicates a favorable equilibrium sorption with the R2 value of 0.99, indicating that the Langmuir isotherm model fit the experimental sorption data well.

No abstract

No abstract

Background: Chloroaniline is a crucial organic additive commonly applied in medicine, chemical industries, plastics and pesticides. Besides, it is also a widespread pollutant, which has a high degree of persistence, toxicity, accumulation and it is hard to be naturally degraded. Result: 3-chloroaniline (3CA) concentrations were measured in aqueous solution by UV/Vis spectrophotometer. Validation of the calibration curve's linearity, instrumental precision (RSD%), limits of detection and quantification were accomplished. The coefficient of calibration curve (1.0–10.0 mgL-1 3CA) had a high correlation (R² = 0.9997) and the instrumental precision was in the range (RSD% = 0.50–0.74%, n=10). The LOD and LOQ from the regression analysis were 0.20 mgL-1 and 0.61 mgL-1, respectively. A treated coffee waste adsorbent was utilized for 3-chloroaniline removal by process of sorption from aqueous solution. The major components of the coffee waste are the hemicellulose, cellulose, and lignin. The temperature effect (25°C, 35°C and 45°C) on sorption was evaluated, with sorption decreasing by increasing of temperature. Isotherms type L were found and associated with monolayer sorption. The parameters of sorption were examined by employing Langmuir, Freundlich and Dubinin-Radushkevich sorption models. The isotherm models of Langmuir and Dubinin-Radushkevich had acceptable correlation coefficients (R2). The Langmuir and Dubinin-Radushkevich sorption capacities of 3-chloroaniline were found to be 44 to 50 mgg−1. The values of separation factor (RL) were ranging from (0-1) which indicated a favourable sorption. In thermodynamic study the physical sorption process was confirmed by van’t Hoff equation. In addition, the free energy ∆G° and enthalpy ∆H° had negative values which suggested that the sorption was spontaneous, and the process was exothermic. Conclusion: Since the adsorbent used in this study is abundant and available, it is considered a potential adsorbent material for 3CA removal from aqueous fluids and suitable for the wastewater treatment.