Designing activated carbon and zeolite amended biosand filters: optimization using response surface methodology

• Published in: Desalination and water treatment 2017-10, Vol.93, p.48-60
• Main Authors: Mirbagheri, Seyed Ahmad, Malekmohamadi, Sima, Ehteshami, Majid
• Format: Article
• Language: English
• Subjects: Activated carbon; Biosand filter; Box-Behnken; Response surface methodology; Runoff; Zeolite
• ISSN: 1944-3986
• DOI: 10.5004/dwt.2017.21458

Biosand filters can be amended with activated carbon and zeolite in order to improve their efficiency at removing micropollutants. The tested pollutants here include ammonia (5 mg/L), lead (210 μg/L), phosphate (12 mg/L), COD (400 mg/L), and iron (0.4 mg/L). The response surface methodology (RSM) is used to evaluate the influence of the adsorbents’ column heights (H) and lead ([Pb]) on system efficiency. The results show that (i) increased H values enhanced filter efficiency; (ii) increased [Pb] values only influenced the lead concentration of the effluent; (iii) there was a higher removal of ammonium, COD, and phosphate; and (iv) the removal of iron was below the allowable level. The RSM results suggest that heights of 33 cm and 26 cm could be considered optimal for zeolite and activated carbon, respectively. The optimized filter quantitatively removed biological pollutants and was capable of removing ammonium, lead, COD, and phosphate pollutants at upto 98, 98, 97, and 87%, respectively. Amending biosand filters with efficient adsorbents enables them to be used to remove micropollutants.