Phosphate Removal from Digested Sludge Supernatant Using Modified Fly Ash
The removal of phosphate in digested sludge supernatant by modified coal fly ash was investigated in this study. Modification of the fly ash by the addition of sulfuric acid could significantly enhance its immobilization ability. The experimental results also showed that adsorption of phosphate by the modified fly ash was rapid with the removal percentage of phosphate reaching an equilibrium of 98.62% in less than 5 minutes. The optimum pH for phosphate removal was 9 and the removal percentage increased with increasing adsorbent dosage. The effect of temperature on phosphate removal efficiency was not significant from 20 to 40 °C. X‐ray diffraction and scanning electron microscope analyses showed that phosphate formed an amorphous precipitate with water‐soluble calcium, aluminum, and iron ions in the modified fly ash.
Comparison of the efficiency of modified clinoptilolite with HDTMA and HDP surfactants for the removal of phosphate in aqueous solutions
Abstract Clinoptilolite (CP) and its modified forms with two cationic surfactants (HDTMA-Br and HDP-Br) were used to remove phosphate as an important anionic environmental contaminant using batch and continuous methods. The modification was analyzed by FT-IR and DTG characterization techniques. The effects of some interfering anions on the removal extent of phosphate were investigated and more interference was observed by arsenate so the removal extent of phosphate decreased to 0.3 mmol/kg. The removal efficiency of phosphate confirmed that HDTMA-modified zeolite (SMZ-HDTMA) was more efficient than HDP-modified zeolite (SMZ-HDP). ΔG values of −6.4, −9.5 and −12.0 kJ/mol for the raw CP, SMZ-HDP and SMZ-HDTMA, respectively, confirm that the removal reaction of phosphate is spontaneous for the raw and modified sorbents. Results of study of pH showed that stronger basic pHs are suitable for removal of phosphate by the raw and modified adsorbents so the removal efficiencies of 8.1, 376 and 675 mmol/kg were, respectively, obtained for CP, SMZ-HDP and SMZ-HDTMA at pH 12.
Two weddings and a lawsuit: Marriage litigation in fourteenth-century Portugal
Based on one of the few surviving records of marriage cases brought before
 ecclesiastical courts in fourteenth-century Portugal, this article offers a rare
 glimpse of marriage practice in a small village in a remote corner of Western Europe
 and the complex ties that bound its inhabitants and which secular and ecclesiastical
 authorities sought to regulate. Clear parallels can be drawn with the patterns of
 marriage litigation observed in England and Northern France, but evidence also
 suggests that royal legislation played an important part in the resolution of marital
 disputes and in the shaping of conjugal behaviour.