摘要

Three indoor filter dam mesocosms, filled with volcanic rock and slag with good adsorption capacity, were constructed to study the effects of different packing arrangements on the purification of slightly-polluted water. Accordingly, we set three different matrix combinations: uniform mixing of volcanic rock and slag, volcanic rock followed slag and slag followed volcanic rock along the water flow, respectively. The results showed that all three mesocosm systems had obvious purification effects on the simulated slightly- polluted water. The highest removal rates of total nitrogen (TN), total phosphorus (TP), ammonium nitrogen (NH3-N) and chemical oxygen demand (COD) were 85.7%, 46.5%, 47.2% and 53.4%, respectively. The packing arrangements had a limited effect on the removal of COD and NH3-N. However, the uniform mixing configuration mesocosm system had the best performance on TP removal, and the mesocosm system filled with slag followed volcanic rock along water flow showed the highest average TN removal rate. The dominant bacteria identified in the mesocosm system filled with mixed slag and volcanic rock were Aeromonas, which could contribute to TP removal. Meanwhile, the dominant bacteria Enterobacterium were found in the other two mesocosm systems. Enterobacterium can produce N2, which accounted for the better TN removal performance in the mesocosm system filled with slag followed volcanic rock along water flow.

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