Nutrient removal from digested swine wastewater by combining ammonia stripping with struvite precipitation

Leipeng Cao, Jingjing Wang, Shuyu Xiang, Zhenghua Huang, Roger Ruan, Yuhuan Liu

Research output: Contribution to journalArticle

15 Scopus citations

Abstract

Typical biological processing is often challenging for removing ammonia nitrogen and phosphate from swine wastewater due to inhibition of high ammonia on activity of microorganisms, exhaustion of time, and low efficiency. In this study, a physicochemical process by combining ammonia stripping with struvite precipitation has been tested to simultaneously remove ammonia nitrogen, phosphate, and chemical oxygen demand (COD) from digested swine wastewater (DSW) with high efficiency, low cost, and environmental friendliness. The pH, temperature, and magnesium content of DSW are the key factors for ammonia removal and phosphate recovery through combining stripping with struvite precipitation. MgO was used as the struvite precipitant for NH 4 + and PO 4 3− and as the pH adjusted for air stripping of residual ammonia under the condition of 40 °C and 0.48 m 3  h −1  L −1 aeration rate for 3 h. The results showed that the removal efficiency of ammonia, total phosphate, and COD from DSW significantly increased with increase of MgO dosage due to synergistic action of ammonia stripping and struvite precipitation. Considering the processing cost and national discharge standard for DSW, 0.75 g L −1 MgO dosage was recommended using the combining technology for nutrient removal from DSW. In addition, 88.03% NH 4 + -N and 96.07% TP could be recovered from DSW by adsorption of phosphoric acid and precipitation of magnesium ammonium phosphate (MAP). The combined technology could effectively remove and recover the nutrients from DSW to achieve environmental protection and sustainable and renewable resource of DSW. An economic analysis showed that the combining technology for nutrient removal from DSW was feasible.

Original languageEnglish (US)
Pages (from-to)6725-6734
Number of pages10
JournalEnvironmental Science and Pollution Research
Volume26
Issue number7
DOIs
StatePublished - Mar 8 2019

Keywords

  • Digested swine wastewater
  • NH -N
  • Phosphorus recovery
  • Stripping
  • Struvite precipitation
  • Volatile solid

PubMed: MeSH publication types

  • Journal Article

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