Most efficient mesoporous Mn/Ga-PCH catalyst for low-temperature selective catalytic reduction of NO with C3H6

The impregnation method was used to prepare a new Mn/Ga-PCH catalyst by using montmorillonite as a host clay for the synthesis of porous clay heterostructures (PCH) as catalyst support, and low-temperature selective catalytic reduction (SCR) of NO by C3H6 over PCH-based catalyst was explored. The effect of the Mn and Gaporous clay heterostructures supported catalysts were studied by ICP, XRD, SEM, N-2 adsorption-desorption, XPS, and Py-FTIR. The 8Mn/3Ga-PCHs (8 wt% Mn and 24 wt% Ga loading) catalyst exhibited 95% NO conversion at 300 degrees C and noticed that above 70% conversion of NO was achieved at low-temperature (150-250 degrees C). The active Mn metal addition resulted in high NO conversion at low temperature for the 8Mn/3Ga-PCH catalyst due to more surface acidic sites, amorphous Ga and Mn formation, and Mn4+ and Mn3+ ratio. In addition, the catalytic activity sequence is consistent with Mn3+/Mn4+, implying that high-valence manganese may represent the active sites for NO conversion at low temperature

Statistical Analysis and Health Risk Assessment: Vegetables Irrigated with Wastewater in Kirri Shamozai, Pakistan

One of the primary environmental routes through which humans are exposed to metals and may be exposed to health risks is the food chain’s contamination with heavy metals. The study observed the risks posed by contaminants in vegetables produced in soil that received wastewater irrigation, as well as their origins and the human health impacts. Eight harmful metals (Cu, Fe, Zn, Mn, Pb, Cd, Ni, and Cr) were tested for concentration levels in water, soil, and vegetable samples using analytical techniques and an atomic absorption spectrophotometer. The present study investigated the potential health implications associated with the consumption of vegetables irrigated using wastewater containing heavy metals. The results indicated a notable accumulation of heavy metals in plant and soil samples obtained from Kirri Shamozai, Pakistan. In comparison to vegetables cultivated in soil irrigated with fresh water, the concentration levels of heavy metals in vegetables grown on soil irrigated with untreated wastewater were considerably higher at (P ≤ 0.001) and above the World Health Organization (WHO) recommended limits. The results showed that heavy metals had significantly accumulated in the soil and had permeated into the crops. Heavy metal concentrations in vegetables cultivated on land irrigated with wastewater were more significant than those grown on land irrigated with freshwater. They exceeded US EPA and World Health Organization (WHO) limits. PCA results for Pb, Cu, and Cr are the main issues impacting water quality and health hazards. The PCA results show that the soil has an extensive loading of heavy metals Cd, Ni, and Mn

Remediation of Emerging Heavy Metals from Water Using Natural Adsorbent: Adsorption Performance and Mechanistic Insights

The presence of potentially toxic metals in water causes a strong impact on environment and human health. In this study, activated biochar was produced by using chemical oxidation method from wheat straw as natural adsorbent and was employed for heavy metals competitive remediation. The morphology, structure, and chemical properties of biochar before and after adsorption were characterized by FTIR, XRD, SEM and EDX mapping techniques. The competitive adsorption efficiency of adsorbent for divalent cadmium (Cd) and lead (Pb) from contaminated water was investigated by using wide range of several initial metal concentration, contact time and pH. Maximum adsorption of Cd(II) and Pb(II) was found in the pH range of 6–8. The adsorption capacity for Cd(II) and Pb(II) was 8.85 and 9.03 mg/g, respectively. Thermodynamics parameters and kinetic models were applied to adsorption data. The isotherm data followed Langmuir model, corresponding to monolayer adsorption of the two ions in the contaminated water. The kinetic data followed the pseudo 2nd order kinetics model, which authenticates the chemisorption nature. The thermodynamic study indicated that Cd adsorption is a spontaneous exothermic process while Pb adsorption is an endothermic process. Mineral precipitation, surface complexation, and cation-π interactions are the major remediation strategies for Cd(II) and Pb(II)