Performance of Agricultural Wastes as a Biofilter Media for Low-Cost Wastewater Treatment Technology

摘要

Aims: The main objective of this work is to evaluate the performance of biofilters with different agricultural wastes media, which widely exist in many regions without being economically used, namely rice straw, date palm fiber and wood chips of orange trees. Using agriculture waste as a biofilter media for municipal wastewater treatment and reducing the accumulation of agricultural waste is an important option to reduce the wastewater treatment cost and for the environmentally safe disposal of agricultural waste in Egypt. Study Design: Pilot study is conducted to investigate the efficiency of three types of agricultural wastes; rice straw, wood chips, orange trees and date palm fiber as a filter media and bio-film material carrier for municipal wastewater treatment. Place and Duration of Study: Benha Faculty of engineering, Benha university, Egypt. Between March 21th and October 10th, 2015. Methodology: The removal efficiency of different municipal wastewater parameters is evaluated through column experiments under different operational conditions for hydraulic rates of 4.8, 6, 8 and 12 m3/m2/d and medium size of fibers of 2 cm, 4 cm, 6 cm and 8 cm. Samples from four different depths for each media are tested to study the effect of depth change in the removal efficiency. Results: The removal efficiency of the Biological Oxygen Demand (BOD₅) was (81.5%±4.8, 88.3%±2.8, and 66.7±5.2) for rice straw, date palm fiber and wood chips of orange trees, respectively. The removal efficiency of the studied biofilter media for Chemical Oxygen Demand (COD) removal was (79.7±5 for rice straw, 88.3±3 for date palm fiber and 64.6±7.24 for wood chips of orange trees. Moreover, the removal efficiency of Total Suspended Solid (TSS) was (82.43±4.9, 86.6±3.9, and 68.3±3.5) for rice straw, date palm fiber and wood chips of orange trees, respectively. The removal efficiency of total nitrogen (N) was (50.21%±2.32, 55%±1.31 and 45±2.38) for rice straw, date palm fiber and wood chips of orange trees, respectively. While The percentage of total phosphorus (P) removal efficiency was 41.92±4.14 for rice straw, 50.52±1.32 for date palm fiber and 32.45±2.30 for wood chips of orange trees. Conclusion: The study revealed that the using of agricultural wastes as biofilter media could be a favorable choice for the biological treatment of municipal wastewater. Date palm fiber was the most efficient media in the removal of wastewater pollutions.