An assessment of mosquito breeding and control in four surface flow wetlands in tropical-subtropical Australia

2003 ◽  
Vol 48 (5) ◽  
pp. 249-256 ◽  
Author(s):  
M. Greenway ◽  
P. Dale ◽  
H. Chapman
Keyword(s):  
Constructed Wetlands ◽  
Open Water ◽  
Surface Flow ◽  
Mosquito Larvae ◽  
Subtropical Climate ◽  
Macroinvertebrate Communities ◽  
Breeding Sites ◽  
Climatic Regions ◽  
Invertebrate Biodiversity ◽  
And Control

In Queensland, Australia, the tropical-subtropical climate is ideal to promote macrophyte growth in surface flow wetlands; however, there have been concerns that constructed wetlands are potential breeding sites for disease-bearing mosquitoes. The aim of this study was to assess whether mosquitoes were breeding in these constructed wetlands, and if so, where they breed, and what parameters might influence breeding: e.g. water quality, vegetation, or macroinvertebrate communities. A study of four surface flow constructed wetlands located in different climatic regions was undertaken. Mosquito larvae were sampled using 240 ml dippers and macroinvertebrates using dip nets. The wetland with the greatest biodiversity of macrophytes and macroinvertebrates had the least number of mosquito larvae (< 1% of all dips). Samples with most mosquito larvae occurred amongst dense mats of Paspalum grass or dead Typha. Despite the presence of larvae in some parts of these wetlands very few late instars or pupae were found i.e. completion of the mosquito life cycle to adult mosquitoes was unsuccessful. This study has shown that the presence of mosquito larvae can be minimised by increasing macro-invertebrate biodiversity, by planting a variety of macrophyte types and species, excluding aggressive plant species, and maintaining at least 30% open water. Macroinvertebrates are probably a crucial factor in the control of mosquito larvae ensuring that predation of the early instars prevents or limits the development of pupae and the emergence of adults.

Comparison of maturation ponds and constructed wetlands as the final stage of an advanced pond system

2005 ◽  
Vol 51 (12) ◽  
pp. 307-314 ◽  
Author(s):  
C.C. Tanner ◽  
R.J. Craggs ◽  
J.P.S. Sukias ◽  
J.B.K. Park
Keyword(s):  
Constructed Wetlands ◽  
Algal Biomass ◽  
Suspended Solids ◽  
Geometric Mean ◽  
Open Water ◽  
Surface Flow ◽  
Effluent Quality ◽  
Treatment Performance ◽  
Pond System ◽  
Load Removal

The treatment performance of a maturation pond (MP), the typical final polishing stage of an Advanced Pond System (APS), is compared with that of a surface-flow constructed wetland (CW) over 19 months. Both received ∼67 mm d−1 of wastewater after passage through upstream stages of the APS. The MP, with greater sunlight exposure, had higher algal biomass (and associated suspended solids) than the CW, showed higher dissolved oxygen (DO) concentrations and greater diurnal variation in DO and pH. Neither polishing stages reduced nutrients markedly, with the CW exporting slightly more NH3-N and DRP, and less NO3-N than the MP. Disinfection was more efficient in the MP (geometric mean 1 log load removal, 12 MPN (100 ml)−1) compared to the CW (0.47 log load removal, 53 MPN (100 ml)−1). Incorporation of a final rock filter (28% of area) reduced median solids levels to <10 g m−3 in both the MP and CW. A hybrid between MPs and CWs with alternating zones of open-water (for enhanced disinfection and zooplankton grazing of algal solids) and wetland vegetation (promoting sedimentation and denitrification, and providing refugia for zooplankton) may provide more consistent effluent quality that either stage alone.

IDENTIFYING THE MOST SUITABLE AREAS FOR SURFACE FLOW WETLAND CONSTRUCTION IN LITHUANIA

2015 ◽  
Author(s):  
Antanas DUMBRAUSKAS ◽  
Nijolė BASTIENĖ ◽  
Petras PUNYS
Keyword(s):  
Constructed Wetlands ◽  
Ecological Status ◽  
Surface Flow ◽  
Gis Analysis ◽  
Proximity Analysis ◽  
Wetland Construction ◽  
The Mean ◽  
Two Phases ◽  
Terrain Features ◽  
Surface Flow Constructed Wetlands

GIS-based approach to find the suitable sites for surface flow constructed wetlands was employed for the Lithuanian river basins with low ecological status. According to the nature of the analysed criteria the flowchart consists of two phases. Criteria used include hydrographical network, soil properties, terrain features, land use, etc. Some of them have strictly defined values (constraints), and other ranges within certain limits (factors). Limited criteria were analysed using rejection principle and influencing factors using proximity analysis and overlay methods. Selecting the potential sites using standard GIS analysis tools there was estimated about 3286 sites for possible wetlands with the mean area of inflow basin about 4 km2 in the basins of water bodies at risk.

scholarly journals Evaluating the performance of horizontal sub-surface flow constructed wetlands: A case study from southern India

2021 ◽  
Vol 162 ◽  
pp. 106170
Author(s):  
Priyanka Jamwal ◽  
Anjali V. Raj ◽  
Lakshmi Raveendran ◽  
Shahana Shirin ◽  
Stephanie Connelly ◽  
...  
Keyword(s):  
Constructed Wetlands ◽  
Surface Flow ◽  
Southern India ◽  
Surface Flow Constructed Wetlands

scholarly journals COLREG-Compliant Optimal Path Planning for Real-Time Guidance and Control of Autonomous Ships

2021 ◽  
Vol 9 (4) ◽  
pp. 405
Author(s):  
Raphael Zaccone
Keyword(s):  
Path Planning ◽  
Real Time ◽  
Collision Avoidance ◽  
Autonomous Navigation ◽  
Optimal Path ◽  
Open Water ◽  
Optimal Path Planning ◽  
Guidance And Control ◽  
Real Time Applications ◽  
And Control

While collisions and groundings still represent the most important source of accidents involving ships, autonomous vessels are a central topic in current research. When dealing with autonomous ships, collision avoidance and compliance with COLREG regulations are major vital points. However, most state-of-the-art literature focuses on offline path optimisation while neglecting many crucial aspects of dealing with real-time applications on vessels. In the framework of the proposed motion-planning, navigation and control architecture, this paper mainly focused on optimal path planning for marine vessels in the perspective of real-time applications. An RRT*-based optimal path-planning algorithm was proposed, and collision avoidance, compliance with COLREG regulations, path feasibility and optimality were discussed in detail. The proposed approach was then implemented and integrated with a guidance and control system. Tests on a high-fidelity simulation platform were carried out to assess the potential benefits brought to autonomous navigation. The tests featured real-time simulation, restricted and open-water navigation and dynamic scenarios with both moving and fixed obstacles.

scholarly journals Enhanced Benzofluoranthrene Removal in Surface Flow Constructed Wetlands with the Addition of Carbon

ACS Omega ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 2865-2872
Author(s):  
Qingqing Cao ◽  
Yan Li ◽  
Yan Kang ◽  
Zizhang Guo
Keyword(s):  
Constructed Wetlands ◽  
Surface Flow ◽  
Surface Flow Constructed Wetlands

Evaluation of submerged surface flow (SSF) constructed wetlands for recirculating tilapia production systems

2008 ◽  
Vol 39 (1) ◽  
pp. 16-23 ◽  
Author(s):  
W.H. Zachritz ◽  
A.T. Hanson ◽  
J.A. Sauceda ◽  
K.M. Fitzsimmons
Keyword(s):  
Constructed Wetlands ◽  
Production Systems ◽  
Surface Flow

scholarly journals Variation of Bacterial and Archaeal Community Structures in a Full-Scale Constructed Wetlands for Wastewater Treatment

Archaea ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Xiu-lu Lang ◽  
Xiang Chen ◽  
Ai-ling Xu ◽  
Zhi-wen Song ◽  
Xin Wang ◽  
...  
Keyword(s):  
Microbial Community ◽  
Constructed Wetlands ◽  
Relative Abundance ◽  
Constructed Wetland ◽  
Free Surface Flow ◽  
Archaeal Community ◽  
Illumina Miseq ◽  
Surface Flow ◽  
Community Structures ◽  
Soil And Water

Microorganisms play important roles in the reduction of organic and inorganic pollutants in constructed wetlands used for the treatment of wastewater. However, the diversity and structure of microbial community in constructed wetland system remain poorly known. In this study, the Illumina MiSeq Sequencing of 16S rDNA was used to analyze the bacterial and archaeal microbial community structures of soil and water in a free surface flow constructed wetland, and the differences of bacterial communities and archaeal compositions between soil and water were compared. The results showed that the Proteobacteria were the dominant bacteria, making up 35.38%~48.66% relative abundance. Euryarchaeotic were the absolute dominant archaea in the influent sample with the relative abundance of 93.29%, while Thaumarchaeota showed dominance in the other three samples, making up 50.58%~75.70%. The relative abundances of different species showed great changes in bacteria and archaea, and the number of dominant species in bacteria was much higher than that in archaea. Compared to archaea, the community compositions of bacteria were more abundant and the changes were more significant. Meanwhile, bacteria and archaea had large differences in compositions between water and soil. The microbial richness in water was significantly higher than that in soil. Simultaneously, soil had a significant enrichment effect on some microbial flora.

Functions of Macrophytes in Constructed Wetlands

1994 ◽  
Vol 29 (4) ◽  
pp. 71-78 ◽  
Author(s):  
Hans Brix
Keyword(s):  
Constructed Wetlands ◽  
Microbial Growth ◽  
Surface Flow ◽  
Wetland Plant ◽  
Intrinsic Properties ◽  
Treatment Processes ◽  
Flow Systems ◽  
Physical Effects ◽  
Uptake Of Nutrients ◽  
Quantitative Importance

Macrophytes have several intrinsic properties that makes them an indispensable component of constructed wetlands. The most important functions of the macrophytes in relation to the treatment of wastewater are the physical effects brought about by the presence of the plants. The macrophytes stabilise the surface of the beds, provide good conditions for physical filtration, prevent vertical flow systems from clogging, insulate against frost during winter, and provide a huge surface area for attached microbial growth. Contrary to earlier belief, the growth of macrophytes does not increase the hydraulic conductivity of the substrate in soil-based subsurface flow constructed wetlands. The metabolism of the macrophytes affects the treatment processes to different extents depending on the design of the constructed wetland. Plant uptake of nutrients is only of quantitative importance in low-loaded systems (surface flow systems). Macrophyte-mediated transfer of oxygen to the rhizosphere by leakage from roots increases aerobic degradation of organic matter and nitrification. The macrophytes have additional site-specific values by providing habitat for wildlife and making wastewater treatment systems aesthetically pleasing.

Sign in / Sign up

Export Citation Format

Share Document