Characterization of the Spatial Variation of Microbial Communities in a Decentralized Subtropical Wastewater Treatment Plant Using Passive Methods

Abstract

Septic tanks (STs), up-flow anaerobic filters (UAFs), and horizontal-flow constructed wetlands (HFCWs) are cost-effective wastewater treatment technologies especially efficient in tropical and sub-tropical regions. In this study, the bacterial communities within a decentralized wastewater treatment plant (WWTP) comprising a ST, a UAF, and a HFCW were analyzed using high-throughput sequencing of the V3–V4 region of the 16S rRNA gene. Bacterial diversity and its spatial variation were analyzed at the phylum and family level, and principal component analysis (PCA) was applied to nitrogen- and organic-matter-degrading families. The highest percentage of nitrogen removal was seen in the HFCW (28% of total Kjeldahl nitrogen, TKN, and 31% of NH3-N), and our results suggest that families such as Rhodocyclaceae (denitrifying bacteria), Nitrospiraceae (nitrifying bacteria), and Rhodospirillaceae (sulfur-oxidizing bacteria) contribute to such removal. The highest percentage of organic matter removal was seen in the UAF unit (40% of biological oxygen demand, BOD5, and 37% of chemical oxygen demand, COD), where organic-matter-degrading bacteria such as the Ruminococcaceae, Clostridiaceae, Lachnospiraceae, and Syntrophaceae families were identified. Redundancy analysis demonstrated that bacterial communities in the HFCW were more tolerant to physicochemical changes, while those in the ST and the UAF were highly influenced by dissolved oxygen and temperature. Also, pollutant removal pathways carried out by specific bacterial families and microbial interactions were elucidated. This study provides a detailed description of the bacterial communities present in a decentralized WWTP located in a subtropical region.

Enhancing nitrogen removal in constructed wetlands: The role of influent substrate concentrations in integrated vertical-flow systems

“…The dominant bacterial groups at the genus level in both systems were unclassified_ Clostridiales , Lactobacillus , unclassified_ Lachnospiraceae , and Faecalibacterium . At the genus level, most of these genera were heterotrophic bacteria able to utilize C and N compounds through fermentation [ 46 ], demonstrating that anaerobic denitrification was the primary denitrification process in the N-6 and N-3 systems. Because of its sensitivity to organic C concentration ( Fig.…”

Role of soil nutrient elements transport on Camellia oleifera yield under different soil types

“…The vertical projection length of the explanatory variable arrow segment on the response variable factor arrow segment is used to represent the degree of influence of the explanatory variable on the response variable. The longer the length, the greater the influence [ 81 ].…”

Tracking the Evolution of Microbial Communities on Microplastics through a Wastewater Treatment Process: Insight into the “Plastisphere”

“…An interesting finding is that the proportion of Firmicutes in the PS was notably increased compared to the background water samples, particularly in the primary treatment. Firmicutes are known to be chemically degrading bacteria and are strongly resistant to extreme environments [56,57]. Therefore, it is plausible that Firmicutes preferentially a ach to the PS due to their capability to degrade organic functional groups in the However, unlike the background water samples, the biofilm PS samples exhibit a closer distance between the PS deployed in the primary treatment and those subsequently deployed in the secondary treatment.…”