Authors: Amelie Shawcross, Chris Kinsley
Published in: CSBE-SCGAB Technical Conferences » 5th CIGR and AGM Quebec City 2021 » Regular Sessions
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Description: As of January 1st, 2011, new dairy farms are required to comply with Part VII.I of the Regulation for Managing Milking Centre Washwater. The new regulation prohibits the direct disposal of milking centre washwater into streams, drainage ditches, or field drainage tiles (OMAFRA, 2016), forcing farmers to construct washwater treatment systems for their operations. Horizontal subsurface flow constructed wetlands (HSSFCW) with pretreatment tanks are proving to be effective in treating dairy parlour washwater.
One farm using a HSSFCW system is the Twin Hill Dairy Farm (THDF) located in Richmond, Ontario. The operation produces approximately 1200 L of washwater daily, which is treated by a septic system followed by a horizontal subsurface flow wetland and finally a tile drainage bed. While the installed system is effective in treating carbon and solids, the system does not effectively remove phosphorus (P) or nitrogen (N).
To remove phosphorus from the washwater, an alum dosing system was designed and installed in the milkhouse. The system doses an alum solution every two hours into the milkhouse collection tank. The system is proving to be effective in treating P, however does not remove N. The following table displays the resulting average phosphorus concentrations (as P) pre and during alum dosing:
Table 1: Pre and with Alum Dosing Concentrations in Milkhouse and Wetland Outlet
Milkhouse Wetland Outlet
Pre-Alum Alum Pre-Alum Alum
TP (mg/L as P) 47.0 5.2 34.2 14.8
Orthophosphate (mg/L as P) 44.0 5.0 35.0 14.0
The results show an 89 % removal of total phosphorus and 89% removal of orthophosphate in the milkhouse. At the wetland outlet, there was a 57 % removal of total phosphorus and 60 % removal of orthophosphate.
Conference name: 5th CIGR International Conference and CSBE-SCGAB AGM 2021, Quebec City,QC, 11-14 May 2021.
Session name: Soil and Water 3 - Water Management & Pollution Control
Publication type: Presentation
Language 1: en
Rights: Canadian Society for Bioengineering