Study of struvite precipitation in anaerobic digesters

Abstract

Abstract--In this paper struvite formation and crystal forms in anaerobic digesters under differing feed types and support media have been studied. Struvite appears when the medium contains magnesium, ammonium and phosphate ions. NH + can be supplied from protein degradation, phosphate from bacterial exudation and Mg 2+ by the supports. The precipitation of struvite has also been checked with real feeding solid wastes plus domestic sewage.

Adsorption kinetics of maxilon yellow 4GL and maxilon red GRL dyes on kaolinite

“…Therefore, the affinity of dyes for kaolinite may be ascribed to Van der Waals forces, electrostatic attractions or hydrogen bonds between the dye and the surface of the particles. These values are consistent with the values in the literature where the activation energy was found to be 43.0 kJ/mol for the adsorption of reactive red 189 on crosslinked chitosan beads [48], 5.6-49.1 kJ/mol for the adsorption of polychlorinated biphenyls on fly ash [49] and 33.96 kJ/mol for the adsorption of maxilon blue GRL on sepiolite [28]. Another aim of this paper is to consider the effect of solution temperature on the transport/kinetic process of dye adsorption.…”

Adsorption kinetics and mechanism of maxilon blue 5G dye on sepiolite from aqueous solutions

“…Therefore, the affinity of maxilon blue 5G for sepiolite may be ascribed to Van der Waals forces, electrostatic attractions or hydrogen bonds between the dye and the surface of the particles. These values are consistent with the values in the literature where the activation energy was found to be 43.0 kJ/mol for the adsorption of Reactive Red 189 on crosslinked chitosan beads [65], 5.6-49.1 kJ/mol for the adsorption of polychlorinated biphenyls on fly ash [66] and 33.96 kJ/mol for the adsorption of maxilon blue GRL on sepiolite [29].…”

Anaerobic Treatment in Decentralised and Source-Separation-Based Sanitation Concepts

“…Formation of struvite forms was observed during biological treatment of hog wastes (Webb & Ho 1992;Wrigley et al 1992;Maqueda et al 1994), poultry wastes (Manninen et al, 1989, wine distillery effluents (Lowenthal et al 1994) and biosolids from biological phosphorus removal processes (Fujimoto et al 1991). A high degree of ammonia removal via MAP was observed from anaerobic sequencing batch reactor (ASBR) effluent with a molar ratio for NH 3 :Mg:(PO 4 -P) of 1:1.25:1 and an optimum pH of 9.5 Miles and Ellis (2001).…”