Simultaneous removal of nutrients from milking parlor wastewater using an AO₂sequencing batch reactor (SBR) system

Abstract

The feasibility of using a lab-scale, anaerobic-aerobic-anoxic-aerobic sequencing batch reactor ((AO)2 SBR) to simultaneously remove biological organics, nitrogen and phosphorus from dairy milking parlor wastewater was investigated in this study. Three hydraulic retention times (HRT = 2.1, 2.7, and 3.5 days) and three mixing-to-process time ratios (TM/TP = 0.43, 0.57, and 0.68) were evaluated as two controlling factors using a 3 × 3 experimental design to determine the optimal combination. Results showed that the HRT of 2.7 days with TM/TP = 0.57 was the best to achieve simultaneous nutrients removal for the influent with initial soluble chemical oxygen demand (SCOD) of about 2000 mg L(-1) (only 0.55 mg L(-1) NH4-N, < 0.1 mg L(-1) nitrate, and 0.14 mg L(-1) soluble phosphorus in the effluent). Good correlations between pH and ORP, and ORP and DO, were also obtained with correlation coefficients all higher than or equal to 0.975. These relationships could be used to develop real-time control strategies to optimize the duration of each operating phase in the (AO)2 SBR system to save energy and enhance treatment efficiency.

Food‐Processing Wastes

“…An AO 2 -SBR system was used to treat wastewater from a milk-parlor operation at different HRTs (2.1, 2.7, and 3.5 days) at three mixing-to-processing time ratios (0.43, 0.57 and 0.68), using a 3x3 factorial design (controlling two factors) to evaluate the optimal combination (Wu and Zhu, 2015). Results showed that the best results were obtained at an HRT of 2.7 days with a mixing-to-processing time ratio of 0.57 for an influent SCOD of 2000 mg/L.…”

Mezclas microbianas en el tratamiento de los residuos líquidos de una sala de ordeño

“…ilking parlors produce several types of waste as the sewage with solid waste (faeces, food remains and mud) and liquids (water, urine, milk remains and cleaning solutions for milking equipment), which IntroductIon M are a consequence of milking (Charlón, 2009). The wastewater from the milking parlor is rich in nutrients, such as protein, fat and lactose, originating from wasted milk, which contributes to organic matter, phosphorous and nitrogen present in liquid waste, bringing about contamination problems due to the high values of biochemical oxygen demand (BOD) or chemical oxygen demand (COD), in addition to representing a source of harmful bacteria, such as the coliforms (Kern, Idler & Carlow, 2000;Shah & Patel, 2013;Wu & Zhu, 2015).…”