Effect of earthworm loads on organic matter and nutrient removal efficiencies in synthetic domestic wastewater, and on bacterial community structure and diversity in vermifiltration

2013 ◽  
Vol 68 (1) ◽  
pp. 43-49 ◽  
Author(s):  
L. M. Wang ◽  
X. Z. Luo ◽  
Y. M. Zhang ◽  
J. J. Lian ◽  
Y. X. Gao ◽  
...  

In this paper, we studied the effect of earthworm loads on the removal rates of chemical oxygen demand (COD), ammonia nitrogen (NH3-N), total nitrogen, and total phosphorus from synthetic domestic sewage and on the bacterial community structure and diversity of substrates in earthworm packing beds. The different vermifiltrations (VFs), including the control, are successful in removing both organic matter (OM) and nutrients. The removal rate of NH3-N at 12.5 g of earthworm/L of soil VF is higher compared with that at 0 and 4.5 earthworm load VFs. The highest Shannon index, in the earthworm packing bed, occurred at 16.5 earthworm load VF. Furthermore, the COD removal rate is significantly correlated with the Shannon index, which reveals that OM removal for synthetic domestic sewage treatment at VF might be more dependent on bacterial diversity at the earthworm packing bed. The band distributions and diversities of the bacterial community for samples from different earthworm loads in VFs suggest that the bacterial community structure was only affected within the earthworm packing bed when the earthworm load reached a certain level. The present study adds to the current understanding of OM and nutrient degradation processes in VF domestic wastewater treatment.

2012 ◽  
Vol 46 (3) ◽  
pp. 1914-1922 ◽  
Author(s):  
Sara J. Dunaj ◽  
Joseph J. Vallino ◽  
Mark E. Hines ◽  
Marcus Gay ◽  
Christine Kobyljanec ◽  
...  

2020 ◽  
Vol 85 ◽  
pp. 1-18
Author(s):  
RC Seballos ◽  
KH Wyatt ◽  
RJ Bernot ◽  
SP Brown ◽  
S Chandra ◽  
...  

Heterotrophic bacteria play a key role in ecosystem processes, but little is known about the factors that shape bacterial community structure in aquatic biofilms, especially in lakes. We used molecular techniques (16S rRNA) to evaluate resource controls on biofilm bacterial community structure in an oligotrophic subalpine lake. We manipulated nutrients (nitrogen and phosphorus; NP) and glucose (G) on inorganic (rock) and organic (wood) substrates under light and dark conditions (i.e. with and without autotrophy, respectively) in a full factorial design using nutrient diffusing substrates in situ for 20 d. Distinct patterns of separation in community structure between treatments with nutrients (NP, NP+G) and without nutrients (control, G-only) indicated that community structure was more strongly influenced by nutrients than organic matter irrespective of substrate type or light availability. Further separation in community structure between treatments with nutrients only (NP) and nutrients with glucose (NP+G) on both organic and inorganic substrates indicated that once nutrient limitation was alleviated, organic matter quality played an important role in shaping community structure. Differences in the relative abundance of 6 phyla, 3 classes, and 19 genera among treatments revealed (1) contrasting taxa-specific resource requirements, (2) the influence of interspecific interactions on composition, and (3) the potential for individual taxa to participate in the decomposition of recalcitrant organic matter. Our findings provide insight into the role that nutrients and organic matter quality play in shaping bacterial community structure, which is a critical step in bridging the knowledge gap between microbial composition and ecosystem function within aquatic environments.


2018 ◽  
Vol 169 ◽  
pp. 46-54 ◽  
Author(s):  
Yibo Wang ◽  
Bin Wang ◽  
Lisa M. Dann ◽  
James G. Mitchell ◽  
Xiaoke Hu ◽  
...  

2014 ◽  
Vol 89 (1) ◽  
pp. 111-126 ◽  
Author(s):  
Tanja Shabarova ◽  
Jörg Villiger ◽  
Oleg Morenkov ◽  
Jutta Niggemann ◽  
Thorsten Dittmar ◽  
...  

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 671
Author(s):  
Jun Liu ◽  
Yong Sun ◽  
Sanjiang Yv ◽  
Jiaquan Wang ◽  
Kaixuan Hu

Industrial wastewater contains high concentrations of inorganic salts and organic matter. This experiment studied a system for treating wastewater containing high concentrations of inorganic salts and organic matter. The setup consists of a closed-cycle humidification and dehumidification system and a filter press. Chemical wastewater was used as the treatment solution, and the treatment performance of the system was tested and analyzed. The system effectively reduced the chemical oxygen demand (COD), electric conductivity (EC), total nitrogen (TN), and ammonia nitrogen (NH4-N) in the wastewater and, at the same time, dehydrated sludge was obtained through a filter press. The system maintains a stable removal rate of each index (COD, EC, TN, and NH4-N) in wastewater and can remove inorganic salts and organic matter from wastewater. The system can successfully treat industrial wastewater containing high concentrations of inorganic salts and organic matter.


2019 ◽  
Vol 11 (3) ◽  
pp. 632 ◽  
Author(s):  
Marina Carrasco-Acosta ◽  
Pilar Garcia-Jimenez ◽  
José Alberto Herrera-Melián ◽  
Néstor Peñate-Castellano ◽  
Argimiro Rivero-Rosales

In this study, the effects of plants on the performance and bacterial community structure of palm mulch-based vertical flow constructed wetlands was studied. The wetlands were built in August 2013; one of them was planted with Canna indica and Xanthosoma sp., and the other one was not planted and used as a control. The experimental period started in September 2014 and finished in June 2015. The influent was domestic wastewater, and the average hydraulic surface loading was 208 L/m2d, and those of COD, BOD, and TSS were 77, 57, and 19 g/m2d, respectively. Although the bed without plants initially performed better, the first symptoms of clogging appeared in December 2014, and then, its performance started to fail. Afterwards, the wetland with plants provided better removals. The terminal restriction fragment length polymorphism (T-RFLP) analysis of Enterococci and Escherichia coli in the effluents suggests that a reduction in their biodiversity was caused by the presence of the plants. Thus, it can be concluded that the plants helped achieve better removals, delay clogging, and reduce Enterococci and E. coli biodiversity in the effluents.


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