Lignocellulose Nanofiber Media for the Enhanced Removal of Copper From Aqueous Solutions

Nowadays, the entry of heavy metals entry into aqueous environments has jeopardized the health of human societies. The experiment was conducted in discontinuous conditions, and the study focused on examining the effect of five parameters including initial concentration, temperature, contact time, pH, and adsorbent dose on the adsorption of Cu heavy metals. In addition, the two-parameter models of Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich were studied and compared to evaluate isothermal absorption. The highest correlation coefficients were obtained for Freundlich (0.969) and Dubinin-Radushkevich (0.9603) models. Finally, thermodynamic parameters such as enthalpy and entropy changes and Gibbs-free energy were calculated as well. The pH parameters, adsorption dose, contact time, temperature, and initial Cu concentrations in the discontinuous system had a statistically significant effect on the adsorption process. The results showed that the maximum efficiency of Cu adsorption by Lignocellulose nanofiber (LCNF) occurred at the pH of 6, contact time of 60 minutes, the ambient temperature of 25°C, and adsorption dose of 0.2 g. In the case of adsorption kinetics, the pseudo-second order model and intra-particle diffusion had more fitness with the experimental data indicating a chemical equilibrium between the adsorbate and the absorbent. Thermodynamic studies demonstrated that the process (negative ∆G) is spontaneous (negative ∆G), endothermic (negative ∆H), and non-random (positive ∆S). Thus, LCNF can be used as an effective adsorbent in the removal of metals by having an extremely high surface area

Application of Chitosan and Activated Carbon Nano-composite in Removal of Nitrite, Phosphate, and Ammonia From Aquaculture Wastewater

Developing an adsorbent with natural components is one of the effective methods to reduce the amount of wastewater pollutants. Wastewater reuse can improve the quality of water prior to entering the natural environment. The aim of this study was to evaluate the efficiency of chitosan nano-composite and activated carbon adsorbent in the removal of nitrite, phosphate, and ammonia pollutants from fish farms of Aq-Qala. To prepare the adsorbents, the shrimp shells were converted to nano-chitosan. The date palm kernel was prepared and activated with oxalic acid in pyrolysis furnace by injecting nitrogen gas into activated carbon, then, the nano-composite was prepared from nanochitosan and activated carbon. A field-laboratory study was conducted during the winter of 2018, and then, batches of synthesized nano-composite were investigated and the effects of pH, initial effluent concentration, and adsorption time were investigated. The experiments were performed in the pH range of 5-8, effluent concentration of 25-100 mg/L, and contact time of 15-90 minutes. The results showed that at optimum conditions (pH of 7, effluent concentration of 50 mg/L, and contact time of 60 minutes), the highest removal percentage and adsorption capacity for nitrite, phosphate, and ammonia contaminants were 99.98%, 99.77%, and 65.65%, and 6.65, 6.14, and 7.32 mg/g , respectively. Due to the high removal percentage (99.98%) of the chitosan and activated carbon nano-composite, the adsorbent was highly capable of removing pollutants (nitrite, phosphate, and ammonia)

Virulence factors of Fusarium spp., causing wheat crown and root rot in Iran

Crown and root rot of wheat, caused by Fusarium spp., limit crop yields worldwide, from rotting of seeds, seedlings, crowns, roots and basal plant stems. Virulence factors and virulence and aggressiveness of Fusarium spp. were investigated for isolates from Iran, obtained from wheat plants with crown and root rot symptoms. Forty isolates of Fusarium were used in this research. Among the isolates, nivalenol (NIV) was detected as the dominant trichothecene chemotype produced. Production of trichothecenes and zearalenone (ZEA) in autoclaved rice cultures of Fusarium isolates was analyzed using high performance liquid chromatography. The levels of NIV ranged from 258 to 1246 μg kg−1, of deoxynivalenol (DON) from 45 to 1411 μg kg−1, and of ZEA from 53 to 3220 μg kg−1. All Fusarium isolates produced cellulase and pectinase enzymes. Positive correlation was observed between activity of cell wall degrading enzymes (CWDEs) produced by the isolates and their pathogenicity on wheat leaf segments. Virulence of trichothecene-producing isolates was greater than that of non-trichothecene-producing isolates. Considerable association was detected between the capability of Fusarium spp. isolates to produce virulence factors (such as mycotoxins and CWDEs) and their pathogenicity on wheat