Moisture Effects on Nitrogen Availability in Municipal Biosolids from End-of-Life Municipal Lagoons

作者：Jeke Nicholson N; Zvomuya Francis^*; Ross Lisette

来源：Journal of Environmental Quality, 2015, 44(6): 1883-1891.

DOI：10.2134/jeq2015.02.0084

Nitrogen (N) availability affects plant biomass yield and, hence, phytoextraction of contaminants during phytoremediation of end-of-life municipal lagoons. End-of-life lagoons are characterized by fluctuating moisture conditions, but the effects on biosolid N dynamics have not been adequately characterized. This 130-d laboratory incubation investigated effects of three moisture levels (30, 60, and 90% water-filled pore space [WFPS]) on N mineralization (N-min) in biosolids from a primary (PB) and a secondary (SB) municipal lagoon cell. Results showed a net increase in N-min with time at 60% WFPS and a net decrease at 90% WFPS in PB, while N-min at 30% WFPS did not change significantly. Moisture level and incubation time had no significant effect on N-min in SB. Nitrogen mineralization rate in PB followed three-half-order kinetics. Potentially mineralizable N (N-0) in PB was significantly greater at 60% WFPS (222 mg kg(-1)) than at 30% WFPS (30 mg kg(-1)), but rate constants did not differ significantly between the moisture levels. Nitrogen mineralization in SB followed first-order kinetics, with N 0 significantly greater at 60% WFPS (68.4 mg kg(-1)) and 90% WFPS (94.1 mg kg(-1)) than at 30% WFPS (32 mg kg(-1)). Low N-min in SB suggests high-N-demanding plants may eventually have limited effectiveness to remediate biosolids in the secondary cell. While high N-min in PB would provide sufficient N to support high biomass yield, phytoextraction potential is reduced under dry and near-saturated conditions. These results have important implications on the management of moisture during phytoextraction of contaminants in end-of-life municipal lagoons.

• 出版日期2015-12