Treatment of screened dairy manure by upflow anaerobic fixed bed reactors packed with waste tyre rubber and a combination of waste tyre rubber and zeolite: Effect of the hydraulic retention time
The research paper presents a study on the treatment of dairy manure using two laboratory-scale upflow anaerobic fixed bed reactors (AFBRs). One reactor (R1) was packed with a combination of waste tyre rubber and zeolite, while the other (R2) used only waste tyre rubber as a support for microorganism immobilization. The study aimed to evaluate the impact of hydraulic retention time (HRT) on the reactors' performance, specifically focusing on the removal efficiencies of chemical oxygen demand (COD), biochemical oxygen demand (BOD5), total solids (TS), volatile solids (VS), and methane yield.
The results indicated that increasing the HRT from 1.0 to 5.5 days improved effluent quality, with R1 consistently outperforming R2 in terms of removal efficiencies. The study found that the COD removal efficiency increased with HRT, achieving a maximum of 82.1% in R1 at 5.5 days, compared to 76.9% in R2. Methane yield was also significantly higher in R1, with increases of 12.5% and 40% at HRTs of 5.5 and 1.0 days, respectively. The reactors demonstrated the ability to operate efficiently at HRTs five times lower than conventional digesters, highlighting the advantages of using a combination of waste tyre rubber and zeolite as a support medium.
The study concludes that AFBRs can effectively treat dairy waste with reduced reactor volumes and lower HRTs, making them a viable alternative to traditional anaerobic digestion methods.
This research paper is significant in the field of waste management and renewable energy, particularly in the context of anaerobic digestion of agricultural waste. It contributes to ongoing discussions about sustainable waste treatment methods by demonstrating the effectiveness of innovative reactor designs that utilize waste materials as support media. The findings offer practical insights for improving the efficiency of biogas production from dairy manure, which is crucial for reducing environmental impacts associated with livestock farming. The study's results can inform the design of pilot-scale reactors and encourage the adoption of more sustainable practices in the agricultural sector.
