A novel modified fenton-like process for efficient remediation of anthracene-contaminated soils before analysis by ultraviolet–visible spectroscopy

Due to the persistence of polycyclic aromatic hydrocarbons (PAHs) in soil and sediments, and their toxic, mutagenic, and carcinogenic effects, the remediation of PAH-contaminated sites is an important role for environment pollution. In this study, the chemical oxidative remediation of anthracene-contaminated soils was investigated by magnetite nanoparticles (Fe3O4) catalyzed Fenton-like oxidation in the presence of hydrogen peroxide 30% (H2O2) and urea-hydrogen peroxide (UHP) at neutral pH. Urea-hydrogen peroxide (UHP), as a safer oxidizing agent, is used for the first time in the Fenton process. The magnetite nanoparticles improved the production of hydroxyl radicals, and the removal of polycyclic aromatic hydrocarbons (anthracene as a model compound) from the soil samples. The structure of Fe3O4 nanoparticles was characterized by FT-IR, XRD, SEM, and vibrating sample magnetometer (VSM). The removal efficiency of anthracene at an initial concentration 2500 (mg kg-1) was 95% for 2.5 mmol by using hydrogen peroxide and 93% for 0.1 mmol of UHP at the optimum oxidation condition. The anthracene reaction was analyzed by ultraviolet-visible spectroscopy (UV-Vis). The UHP safety and efficiency, neutral pH condition, the limited iron leaching and its easy magnetic separation makes magnetite nanoparticles-UHP a promising catalytic system in remediation of polycyclic aromatic hydrocarbons in contaminated soils.

Nutrient Dynamics in Sandy Soil and Leaf Lettuce following the Application of Urea and Urea-Hydrogen Peroxide Impregnated Co-Pyrolyzed Animal Manure and Bone Meal

There is a paucity of data regarding the effect of nutrient-enriched biochar amendments on nutrient dynamics in both soil and crops. This is important because unlike pristine biochar, nutrient-enriched biochar is applied to the soil in minute quantities as large amounts may led to over application of the nutrients loaded in it. The current study examined the effects of both phosphorus- and nitrogen-enriched biochars on the dynamics of both macro and micronutrients in the sandy soil and leaf lettuce grown thereon. The phosphorus enrichment followed co-pyrolysis of animal manure (cow dung) with 25% and 50% bone meal (w/w), while the nitrogen enrichment was achieved by soaking the co-pyrolyzed biochar into urea and urea-hydrogen peroxide. The performances of the nutrient-enriched biochar were compared with the conventional amendment of urea and triple superphosphate (TSP) in the production of leaf lettuce over a period of two seasons in a pot experiment. The nutrient-enriched biochar amendments resulted into higher microbial biomass carbon and carbon to nitrogen ratios than the conventional amendment. The conventional amendment caused more phosphorus, potassium, and magnesium accumulations in the leaf lettuce than the nutrient-enriched biochar amendments. The nutrient-enriched biochar amendments led to more accumulations of nitrogen, calcium, and micronutrient elements in the leaf lettuce and availabilities of all the nutrient elements in the soil and thus, nutrient-enriched biochar acted as a reservoir that could provide nutrients to the growing lettuce beyond a single growing season.