Research progress on phosphorus recovery from incinerated sewage sludge ash based on wet-chemical techniques

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Research progress on phosphorus recovery from incinerated sewage sludge ash based on wet-chemical techniques

Journal Title: Energy Environmental Protection - Year 2023, Vol 37, Issue 5

Abstract

As one of the essential nutrients for plant growth, phosphorus plays an in dispensable role inthe development of modern agriculture and is in great demand. Since global phosphorus reserves are limited and phosphorus resources are not renewable, incinerated sewage sludge ash (ISSA) is considered to be a potential secondary phosphorus resource due to its high phosphorus content and huge annual production. The paper summarizes the current status of research on the recovery of phosphorus from ISSA based on wet-chemical technology, which mainly includes the phosphorus extraction process and the subsequent production process of phosphorus products. The phosphorus extraction process mainly involves acid extraction using acidic reagents, alkaline extraction based on alkaline reagents, and continuous extraction with a combination of various methods. The phosphorus production process primarily yields phosphorus products from phosphorus-rich solutions by means of chemical precipitation and crystal precipitation, generally yielding calcium phosphorus (Ca-P), struvite (MgNH_4PO_4·6H_2O) and vivianite (Fe_3(PO_4) 2·8H_2O), all of which can be used as phosphorus fertilizers to promote plant growth. The difficulty of recovering phosphorus products from ISSA based on wet-chemical technology is that sludge incineration ash is enriched with a large number of heavy metals and other impurity elements, and it is necessary to reduce the content of impurities in the solution through various purification pretreatment means, so as to improve the purity of the subsequently recovered phosphorus products. Inthis paper, various purification pretreatment means based on wet-chemical technology are reviewed, mainly including ion exchange impurity removal technology (CER), phosphorus adsorption-desorption technology, and precipitation impurity removal technology through pH control. In conclusion, this paper discusses the feasibility and necessity of recovering phosphorus products from ISSA, summarizing the methods and technical routes of recovering phosphorus products from ISSA based on wet- chemical technology, revealing the basic principles of recovering phosphorus products from ISSA using wet-chemical technology, and providing technical references for developing new technologies for recovering phosphorus from ISSA.

Authors and Affiliations

HU Shaogang|School of Environmental Science and Engineering, Peking University, China, ZHANG Jing|School of Environmental Science and Engineering, Peking University, China, YANG Wulin*|School of Environmental Science and Engineering, Peking University, China,

Keywords

EP ID EP738015
DOI 10.20078/j.eep.20230905
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