Performance evaluation of various individual and mixed media for greywater treatment in vertical nature-based systems

Snigdhendubala Pradhan, Mohamed I. Helal, Sami G. Al-Ghamdi, Hamish R. Mackey

Research output: Contribution to journalArticle

Abstract

Nature-based systems (NBS) are a cost-effective, energy efficient and aesthetically pleasing approach for greywater treatment, but they are space intensive. Vertical NBS overcome this issue but must utilize lightweight media to reduce their construction costs. This study evaluates four common plant growing media: perlite, coco coir, LECA and sand, and compares them with two new media derived from local waste materials: date seeds and spent coffee grounds (SCG). The media are characterized and tested for their removal of various greywater pollutants. Further tests are conducted comparing mixtures of perlite-coco coir and date seeds-SCG. SCG was found to be an excellent media for greywater treatment, providing a similar degree of treatment as the best traditional media, coco coir and providing improved drainage. Drainage was further improved by mixing SCG with date seeds, which performed better than any mixture of perlite and coco coir. Most pollutants showed a slight deterioration in treatment performance with this mixture, although the removal of suspended solids and chemical oxygen demand was improved. An increased bed height improved the treatment performance with SCG, while increased hydraulic loading resulted in decreased treatment performance for all media. This study demonstrates the potential of date seeds and SCG as locally recycled waste materials to realize treatment of greywater in vertical NBS.

Original languageEnglish
Article number125564
JournalChemosphere
Volume245
DOIs
Publication statusPublished - Apr 2020

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Keywords

  • Date seed
  • Greywater treatment
  • Hydraulic loading
  • Plant growing media
  • Spent coffee ground
  • Urban greening

ASJC Scopus subject areas

  • Environmental Engineering
  • Environmental Chemistry
  • Chemistry(all)
  • Pollution
  • Health, Toxicology and Mutagenesis

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