Fine mesh rotating belt sieves (RBS) offer a very compact solution for removal of particles from wastewater. This paper shows examples from pilot scale testing of primary treatment, chemically enhanced primary treatment (CEPT) and secondary solids separation of biofilm solids from MBBRs.
Maximum sieve rate tested was 288 m³/m²-h and maximum particle load was 80 kg TSS/m²-h. CEPT is a simple and effective way of increasing the removal efficiency of RBS. Adding about 1 mg/L of cationic polymer and about 2 min of flocculation time the removal of TSS typically increased from 40-50 % without polymer to 60-70 % with polymer.
Authors: Rusten B., Rathnaweera S., Rismyhr E., Sahu A. K. and Ntiako J.
Fine mesh rotating belt sieves (RBS) offer a very compact solution for removal of particles from wastewater. This paper shows examples from pilot-scale testing of primary treatment, chemically enhanced primary treatment (CEPT) and secondary solids separation of biofilm solids from moving bed biofilm reactors (MBBRs).
Primary treatment using a 350 microns belt showed more than 40% removal of total suspended solids (TSS) and 30% removal of chemical oxygen demand (COD) at sieve rates as high as 160 m³/m²-h. Maximum sieve rate tested was 288 m³/m²-h and maximum particle load was 80 kg TSS/m²-h.
When the filter mat on the belt increased from 10 to 55 g TSS/m², the removal efficiency for TSS increased from about 35 to 60%. CEPT is a simple and effective way of increasing the removal efficiency of RBS. Adding about 1 mg/L of cationic polymer and about 2 min of flocculation time, the removal of TSS typically increased from 40–50% without polymer to 60–70% with polymer.
Using coagulation and flocculation ahead of the RBS, separation of biofilm solids was successful. Removal efficiencies of 90% TSS, 83% total P and 84% total COD were achieved with a 90 microns belt at a sieve rate of 41 m³/m²-h.
Read the full publication:
Rusten, Bjørn; Rathnaweera, Subhash S.; Rismyhr, Eirik; Sahu, Ashish K. and Ntiako, Jonas: Rotating belt sieves for primary treatment, chemically enhanced primary treatment and secondary solids separation. Water Science & Technology, Vol. 75, No. 11, pp. 2598-2606, 2017.