In this paper, we prove that mesocompactness is inversely preserved under paracompact mappings with regular images. As an application of this result, we prove that mesocompactness is inversely preserved under closed Lindelof mappings with regular domains and images, which answers a question on mesocompactness posed by S. Lin. We also give a counterexample to show that the regularity of domains in this application can not be omitted.
The effects of species compositions (two-species mixtures or monocultures) and hydraulic retention times (HRT; 1, 4, 8, 16, 24, 48 hours) on total nitrogen (TN) and total phosphorus (TP) removal from eutrophic water were studied in a constructed wetland. Two species mixtures showed higher efficiency to remove TN and TP than monocultures. Average removal efficiency of TN and TP was 49.6% and 34.0%, respectively. A longer HRT enhanced the removal efficiency of TN and TP, which suggested that species mixtures, HRT, and species mixtures × HRT interaction were useful for increasing the wastewater TN and TP removal.