Development of attapulgite composite ceramsite/quartz sand double-layer biofilter for micropolluted drinking source water purification

Abstract

This study compared start-up and steady-state affecting factors of attapulgite composite ceramsite/quartz sand double-layer biofilter (ACC/QSDLBF) and quartz sand single-layer biofilter (QSSLBF) on micropolluted drinking source water treatment. Results showed that the ACC has suitable pore size distribution in the range of 5-850 nm which is conducive to biofiltration. Turbidity removal efficiency of ACC/QSDLBF was a little lower than QSSLBF, but organic matters and ammonia removal efficiencies of ACC/QSDLBF were much higher than QSSLBF due to biodegradation and nitrification by microorganisms colonizing on the ACC. At stable state, the growth of head loss for ACC/QSDLBF was lower than that of QSSLBF. The complete filtration cycle of ACC/ QSDLBF was 52 h. The total COD Mn removal rate of ACC/QSDLBF was 20.93 %, in which 90 % of removed total COD Mn was achieved at the upper 60 cm of ACC filter layer. The removal of COD Mn decreased from 35.89 to 13.16 % in ACC/QSDLBF when increasing hydraulic loading from 2 to 16 m/h. After analysis of efficient EBCT in ACC/QSDLBF, optimized hydraulic loading was 12 m/ h. These conclusions would be helpful to practical application of ACC as functional material for new construction of waterworks, especially upgrading of existing waterworks treating micropolluted drinking source water.

Rainwater treatment: an approach for drinking water provision to indigenous people in Ecuadorian Amazon

“…The clay spheres were dried at room temperature (20 ± 2 °C). The spheres were calcined at 850 °C for 2 h (at 5 °C/min rate) (Ajayi and Lamidi 2015;Wang et al 2016). It was used a column configuration similar to that of GF column.…”