Research on Improving the Removal Efficiency of Nitrogen and Phosphorus in Hanoi Brewery Wastewater by Using Nano Fe0

Abstract

The brewery is one of the industries that generates enormous amounts of wastewater. Brewery wastewater contains high concentrations of organic matter, but low concentrations of heavy metals. Without proper treatments before discharging, the wastewater from this industry can pose serious risks to human health, the environment, and aquatic life. At present, the Hanoi brewery in Hung Yen province is producing beer with 50 million liters/year and discharging about 450m³ of wastewater per day. The effluent from the current wastewater treatment system of the brewery can only meet the National Technical Regulation QCVN 40: 2011/BTNMT (column B), especially for nitrogen and phosphorus. Thus, this study focused on improving the removal efficiency of nitrogen and phosphorus from the brewery wastewater by using nano zero-valent iron (nZVI). The results showed that the concentrations of TSS, BOD₅, COD, N_TS, NH₄⁺, total P and Coliform in the brewery wastewater were 10.4, 36.7, 24.3, 3.2, 5.96, 8.02 and 100.7-fold (respectively) higher than those of the National Technical Regulation QCVN 40:2011/BTNMT (Column A). With a dose of 0.2 g/L of the nZVI added to the sedimentation tank, the concentrations of N-NO₃^- and P-PO₄^3- in the effluent decreased to 14.02 and 2.4 mg/L, respectively; total N and P decreased to 19.96 and 2.54 mg/L, respectively, meeting the National Technical Regulation.