ZHAOQing,SUNYong-li,HUANGPeng,et al.Diurnal Variation of Vallisneria and Microorganisms Attached to the Stems and Leaves for Water Purification[J].China Water & Wastewater,2024,40(9):98-106.
Diurnal Variation of Vallisneria and Microorganisms Attached to the Stems and Leaves for Water Purification
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第40卷
Number:
第9期
Page:
98-106
Column:
Date of publication:
2024-05-01
- Keywords:
- submerged plants; microorganism attached to the stems and leaves; nitrogen and phosphorus removal; diurnal variation
- Abstract:
- A large number of microorganisms are attached to the stems and leaves of submerged plants, and their main photosynthetic sites are in the stems and leaves. At present, the diurnal variation of nitrogen and phosphorus removal performance of stem and leaf attached microorganisms under photosynthesis and respiration of submerged plants is still unclear. In this paper, part of the stems and leaves of a typical submerged plant Vallisneria were cleaned after culture for a period of time to make a comparison with the uncleaned stems and leaves. The changes of DO, ORP and other indicators of the water bodies with two kinds of Vallisneria were observed within 24 h. The nitrogen and phosphorus removal reactions of the microorganisms attached to stems and leaves were characterized by changes in N and P concentrations, and combined with microscopy and high?throughput sequencing technology for comprehensive analysis. The diurnal difference of DO in the water with less stem and leaf attached microorganisms was 9.1 mg/L, and the other indexes fluctuated little. The DO and ORP of the water with abundant stems and leafs attached microorganisms fluctuated in the range of 0-3.7 mg/L and 0-150 mV, respectively. During the daytime, the NH3+-N in water decreased, the NO3--N in water increased, and PO43--P and TP in water decreased, indicating that nitrification, aerobic denitrification and phosphorus removal reactions occurred. The changes of N and P indexes at night were opposite to those during the daytime, and denitrification and phosphorus release reactions occurred. There were many types of aerobic, facultative and anaerobic microorganisms attached to the stems and leaves of Vallisneria. The dominant bacterial phylum was Proteobacteria, and the dominant bacterial genus was norank_f__Rhizobiales_Incertae_Sedis. Among the top 20 dominant bacterial genera in terms of abundance, there were 14 functional bacteria related to nitrogen and phosphorus removal, of which 10 were denitrifying bacteria with relative abundance of 36.43%, including 3 aerobic denitrifying bacteria Hyphomicrobium, Rhodobacter and unclassified_f__Rhizobiaceae. The mechanism of diurnal change of water purification under the joint action of submerged plants and stem and leaf attached microorganisms was similar to the operation principle of attached growth SBR process with intermittent aeration and cyclic time of 24 h.
Last Update:
2024-05-01