Recycling sludge on cropland as fertilizer – advantages and risks

Mahmoud Seleiman, Arja Santanen, Pirjo Mäkelä

Research output: Contribution to journalReview ArticleScientificpeer-review

Abstract

Background: Digested sludge is a good source of plant nutrients. However, depending on the feedstock, it might contain heavy metals, metalloids, organic compounds, pathogens, and pharmaceuticals, which can cause adverse effects on crop growth and contaminate the groundwater, soil, and food chain.

Scope: The aim of this review is to focus on the potential risks of inorganic and organic contaminants to plant growth, soil, groundwater, and consequently the food chain and environment related to the utilization of digested sludge as a fertilizer on cropland.

Conclusions: Inorganic compounds, such as metals and metalloids, in sludge can occasionally cause reductions in soil microbial biomass. In general, the uptake of metals and organic contaminants does not appear to cause a significant hazard to the plants and the concentrations do not surpass the maximum values allowed in soil. Organic compounds, harmful for human health or the environment, are to a large extent decomposed or volatilized from the land treated with sludge, which decreases their leaching into the environment. Many of the organic compounds are lipophilic and can be bound to soil organic matter. In conclusion, the application of sludge on cropland might be a sustainable management practice; however, further investigations are needed to determine the accumulation and persistence of possible hazardous emerging chemicals and pathogens in the environment and formation of harmful intermediate reaction of inorganic and organic compound products.

Original languageEnglish
Article number104647
JournalResources, Conservation and Recycling
Volume155
Number of pages10
ISSN0921-3449
DOIs
Publication statusPublished - Apr 2020
MoE publication typeA2 Review article in a scientific journal

Fields of Science

  • 415 Other agricultural sciences
  • Digestate
  • Food chain
  • Nutrient cycling
  • Pollutants
  • Sustainable agriculture
  • MUNICIPAL SEWAGE-SLUDGE
  • EMERGING ORGANIC CONTAMINANTS
  • WASTE-WATER SLUDGE
  • AGRICULTURAL SOILS
  • HEAVY-METALS
  • CHLORINATED PARAFFINS
  • ANAEROBIC-DIGESTION
  • AQUATIC ENVIRONMENT
  • NITROGEN-FERTILIZER
  • PLANT ACCUMULATION

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