The phosphorus distribution of substrate in different area of both constructed wetland with plant and one without plant

摘要

@@ 1 Introduction The constructed wetlands are made up by aquatic plant, substrate and their associated microbial assemblages, with low-cost for treating municipal, industrial and agricultural wastewater. The removal mechanisms of phosphorus in wastewater are mostly by plant take up and retention of substrate. Comparatively, the latter has more proportion. Except for the surface adsorption of the particles, some chemical elements of these materials, such as iron (Fe), calcium (Ca) and aluminium (Al), could conduct precipitation reaction with soluble phosphate. Both of them mainly form substrate phosphorus retention capacity. But the organic substances biodegradation and oxygen from plant root in constructed wetland in using could lead to active migration and transformation of chemical elements on surface of the substrate, such as oxide iron, which could impact the retention of phosphorus. The objective of this study is to investigate spatial distribution of total phosphorous (TP) and different forms of inorganic phosphorous in substrate of both horizontal sub-surface flow constructed wetland with plant and one without plant after they treating wastewater five months.