Introduction of Plug-flow Anaerobic Sludge Blanket (PASB) reactor for wastewater treatment

Abstract

Plug-Flow Anaerobic Sludge Blanket Reactor (PASB) was used as the experimental reactor for the treatment as a replacement for Up-flow Anaerobic Sludge Blanket Reactor (UASB). The novelty of this study is to analyse the applicability of a novel post-treatment for anaerobically treated water by modifying UASB reactor which might be cost-effective, sustainable, and time-saving in the field of anaerobic treatment. Low-strength and high-strength (Leachate) wastewater (WW) were anaerobically treated under ambient temperature (28ºC-32ºC) with different Hydraulic Retention Time (HRT) values using a PASB and UASB setup. Chemical Oxygen Demand (COD) removal efficiency, biogas production rate, and gas composition were recorded and analysed. The average influent COD concentration of the low-strength wastewater was about 2070 ± 70 mg/L during the operation period of the reactor, and the COD removal efficiency of PASB was 90 ± 0.2 % which was 16 % enhancement at 10 h (hrs) HRT compared to UASB. The maximum biogas production recorded at this HRT was 13.72 ± 0.16 mL/h/L, which was 30.7 % higher than UASB. For leachate, COD concentration was about 6270 ± 220 mg/L, and COD removal efficiency was 97.2 ± 0.2 %. It is about a 23 % increase compared to UASB, at 8 hrs HRT and the maximum biogas production rate obtained for leachate treatment was 71.57 ± 1.53 mL/h/L and it was 30 % escalation than UASB. Hence, the PASB Reactor seems to be a desirable technique in compared with UASB to reach a comprehensive treatment efficiency, with efficient biogas exploitation to meet goals of renewable energy especially in tropical nations where less reactor heating is needed.