Phosphorus removal/recovery from swine manure

Lab and pilot experiments were conducted to develop an efficient, easy-operation process to remove phosphorous from swine manure, while enable simultaneously recovery of the phosphorous, via struvite precipitation. The characteristic of the diluted and pre-settled swine manure were also investigated in this research. The performance of two different reactors was investigated, one was cone-shaped fluidized bed crystallizer (CFB), and another was enhanced struvite crystallizer (ESC). The study results showed that CFB can be applied to treat diluted swine manure, which supposed to have similar characteristic with swine waste lagoon effluent, while ESC can be applied for both pre-settled and diluted swine manure. Up to 64% and 70% total phosphorous removal were reached by CFB and ESC, respectively. Higher Mg dose (up to 2.0) or higher pH value in range of 7.7 ∼ 8.8, would increase the phosphorus removal, while the treatment flow rate would not affect the phosphorus removal significantly in the design range.