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Struvite crystallization method is used to effectively remove high concentration of ammonia nitrogen from leachate during the pretreatment stage of industrial solid waste landfill (ISWL) leachate. The effects of molar ratio of phosphorus to nitrogen (P:N), molar ratio of magnesium to nitrogen (Mg:N) and pH value on ammonia nitrogen removal were discussed. The results indicate that compared with pH adjustment later, pH adjustment first increases the removal rate of ammonia nitrogen by 30–54%. When pH value is 9.5, the removal of ammonia nitrogen reaches 82%; When P:N is 0.9 ∼ 1.1, the removal of ammonia nitrogen is maintained at 78 ∼ 82%; When Mg: N is 1.1 ∼ 1.3, the removal of ammonia nitrogen reaches 90%; When the pH value is 10 and P:N:Mg is 1.1:1:1.2, the removal rate of ammonia nitrogen reaches the highest, reaching 95.9%. [ABSTRACT FROM AUTHOR]

Ferrimagnetic CoFe2O4 (CFO) and ferroelectric Pb(Mg1/3Nb2/3)0.35Ti0.65O3 (PMNT) composite ceramics, [xCFO-(1-x) PMNT for x = 20, 30, 40 and 50 wt.%], were prepared using conventional ceramic processing. The phase structures, surface morphology, dielectric, piezoelectric, and magnetoelectric properties of CFO/PMNT composite ceramics were analyzed. It was found that the phase structures of the CFO/PMNT were mix phase structure of spinel phase and perovskite phase. The maximum value of the piezoelectric constant d33, 212 pC/N, was obtained for the composite with x = 0.2. However, the maximum value of the ME voltage coefficient, 14.4 mV/cm.Oe, was observed for the composite with x = 0.5. [ABSTRACT FROM AUTHOR]

Antimony modified (Na0.5K0.5)NbO3 lead-free piezoelectric ceramics were prepared by conventional electroceramic process. The role of Sb5+ in (Na0.5K0.5)NbO3 perovskite structure B site was discussed. The degree of crystalline structural symmetry increased with Sb5+ content increasing, changing from orthorhombic to pseudocubic. As a result, the thermal stability of crystalline structure and ferroelectric properties of (Na0.5K0.5)NbO3 ceramics decreased. (Na0.5K0.5)NbO3 ceramics with 3 mol% Sb5+ displayed enhanced piezoelectric properties, the piezoelectric constant d33 was 144 pC/N, planar electromechanical coupling coefficient kp was 49%, mechanical quality factor Qm was 160, and Tc = 344°C, respectively. [ABSTRACT FROM AUTHOR]