It is still challenging to develop strongly alkali-resistant catalysts for selective catalytic reduction of NO x with NH 3 . It is generally believed that the maintenance of acidity is the most important factor because of neutral effects of alkali. This work discovers that the redox properties rather than acidity play decisive roles in improving alkali resistance of some specific catalyst systems. K-poisoned Fedecorated SO 4 2À -modified CeZr oxide (Fe/SO 4 2À /CeZr) catalysts show decreased acidity but reserve the high redox properties. The higher reactivity of NH x species induced by K poisoning compensates for the decreased amount of adsorbed NH x , leading to a desired reaction efficiency between adsorbed NH x and nitrate species. This study provides a unique perspective in designing an alkali-resistant deNO x catalyst via improving redox properties and activating the reactivities of NH x species rather than routinely increasing acidic sites for NH x adsorption, which is of significance for academic interests and practical applications.

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).

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One of the key concerns in public health is food security in the food sector. Due to the large amounts of potentially hazardous metals in wastewater, this practice may pose serious environmental and health risks to neighboring residents. In this study, the health effects of heavy metals in vegetables irrigated with wastewater were studied. The findings indicated a massive accumulation of heavy metals in wastewater-irrigated soil and vegetables collected from Bhakkar, Pakistan. The current study looked at the effects of wastewater irrigation on metal buildup in the soil–plant continuum and the health hazards that come with it (Cd, Co, Ni, Mn, Pb, and Fe). Heavy metal concentrations in vegetables cultivated on soil irrigated with untreated wastewater were not significantly lower (p ≥ 0.05) than in vegetables grown on wastewater-irrigated soil and were below the World Health Organization’s recommended limits. A considerable amount of the selected hazardous metals was also swallowed by adults and children who consumed these vegetables, according to the research. On soil that had received wastewater irrigation, Ni and Mn were substantially different at p ≥ 0.001 levels. Pb, Ni, and Cd had health risk scores higher than the ones in all ingested vegetables, while Mn had a health risk score greater than the ones in turnips, carrots, and lettuce. The results also showed that both adults and children who consumed these vegetables absorbed a significant amount of the chosen toxic metals. Pb and Cd were shown to be the most dangerous chemical compounds to human health, and everyday consumption of agricultural plants irrigated with wastewater may pose a health risk, according to the health risk criteria.