Le Fang

TL;DR: Sulphuric acid was the most efficient for P recovery and achieved 94% of total extraction under the optimal conditions, which were 2-h reaction with 0.2 mol/L H2SO4 and liquid-to-solid ratio of 20:1.

TL;DR: In this paper, a two-step extraction method was developed to produce highly purified P-extract where ISSA is treated first with ethylenediaminetetraacetatic acid (EDTA) and then with sulphuric acid.

TL;DR: In this paper, the authors used Mg/Ca-modified biochars to take up P from the acid-extract from incinerated sewage sludge ash (ISSA) at low pH.

TL;DR: In this article, a novel procedure for phosphorus (P) recovery as struvite from incinerated sewage sludge ash (ISSA) was proposed and investigated, which is divided into three steps: transform P in the ISSA to amorphous iron phosphate (Fe P) and aluminum phosphate (Al P) by acid washing followed by alkali precipitation, re-dissolve Fe P and Al P via acid washing and adsorption of Fe and Al ions by a cation exchange resin (CER), and struvites crystallization.

TL;DR: The results showed that a low hydraulic and pozzolanic potential was associated with the ISSA and APCR due to the presence of low contents of SiO2, Al2O3 and CaO and high contents of P, S and Cl, which rendered them classifiable as non-hazardous according to the U.S. EPA and Chinese national regulatory limits.