Cost of ingredients for synthetic wastewater.

The wastewater used for experimental research is typically collected from a wastewater treatment plant or prepared as a synthetic solution in the lab. These options represent transportation and cost challenges, respectively, particularly for experiments requiring large volumes of wastewater. Here, we describe a method for creating inexpensive synthetic wastewater from readily available household products. The base solution, synthesized by soaking dog food pellets for 24 hours and straining the solution, had average nutrient values of 9.7 mg/L ammonia as N, 12.2 mg/L nitrate as N, 227 mg/L total nitrogen, and 4870 mg/L chemical oxygen demand (COD). Degradation tests demonstrated that soluble COD was biodegradable. The base solution was then used to prepare synthetic wastewater that met the requirements for two experimental applications; (1) anaerobic treatment of primary effluent and (2) land-application treatment of secondary effluent. Cost analysis indicated that the single-ingredient synthetic wastewater cost 92% less to produce than synthetic wastewater recipes that used laboratory chemicals, and reduced preparation time. These results demonstrated that use of commercial products can simplify the wastewater synthesis process and reduce experimental costs for large-volume research applications while still maintaining consistent wastewater characterization.