Investigating bioreactor substrates for water quality applications

Johnson, Philip H (2021) Investigating bioreactor substrates for water quality applications. MRes thesis, University of Lincoln.

Investigating bioreactor substrates for water quality applications
MRes Thesis
27.5.21 Johnson Philip - Agri Food Technology March FINAL.pdf - Whole Document

Item Type:Thesis (MRes)
Item Status:Live Archive


Woodchip bioreactors and other edge-of-field water treatment solutions are being increasingly used to address nutrient pollution in freshwater caused by agricultural subsurface drainage. This study evaluates the efficacy of low-cost bioreactor substrates and a steel-waste filter in reducing levels of nitrates and phosphorus in water. In addition to this, the effect of these substrates on the breakdown of clopyralid herbicide is also investigated. Small-scale laboratory bioreactors and steel-waste filters were used to simulate the conditions of a full-size bioreactor while testing different substrate combinations. The woodchip bioreactor achieved average nitrate removal efficiencies of 40.2%, rising to 60.5% with the addition of biomass bottom ash (straw) from an influent water concentration of 42.73mg Nitrate(N)/l. Both of these results are following a hydraulic retention time (HRT) of 48hrs. The steel-waste phosphate filter successfully reduced soluble phosphorus concentrations from an average of 2.84±0.41 to 4.30±0.44 mg/l P after 30 minutes of exposure yielding a max reduction of 87%. The woodchip bioreactor also demonstrated an increase in the rate of clopyralid breakdown. An average reduction in clopyralid concentration of 60% was achieved in a 36-hour period, this equates to a vastly reduced half-life (D50) compared with laboratory and field conditions. The results indicate that edge-of-field woodchip bioreactors, paired with steel-waste filters could be effective in treating agricultural wastewater for nutrient and clopyralid herbicide pollution.

Keywords:bioreactor, water treatment, nutrient pollution, freshwater
Subjects:D Veterinary Sciences, Agriculture and related subjects > D443 Water Resource Management
Divisions:College of Science > Lincoln Institute for Agri-Food Technology
ID Code:48579
Deposited On:16 Mar 2022 11:27

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