An innovative solar energy-powered floating media bed reactor for nutrient removal (I): reactor design

Nutrient impairment of Florida's surface waters due to urban stormwater runoff is a growing concern, resulting in the development of new regulatory policies. Several best management practices (BMPs), such as stormwater retention/detention ponds, help reduce the impact of flooding but may not reduce nutrient loadings sufficiently to meet water quality goals. This paper presents the design and implementation of a floating media bed reactor (FMBR) as a supplementary treatment unit for stormwater wet detention ponds to enhance the removal efficiency of total phosphorus (TP) and total nitrogen (TN). This effort mitigates the adverse effects of stormwater runoff on downstream impaired waterbodies. The FMBR was filled with an engineered mixture of adsorption media made of natural and recyclable materials and operates on a 24 h continuous cycle, powered by a small photovoltaic pumping system. Significant reductions in TP and TN were documented across the FMBR achieving varying degree of removal efficiencies for storm and non-storm events with fluctuating temperatures. The outcome expands the state of the art stormwater treatment technology and encourages stormwater reuse as an alternative source of freshwater.