How ‘Green’ Are Aquaculture, Constructed Wetlands and Conventional Wastewater Treatment Systems?

1999 ◽  
Vol 40 (3) ◽  
pp. 45-50 ◽  
Author(s):  
Hans Brix
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Constructed Wetlands ◽  
Plant Biomass ◽  
Renewable Energy Sources ◽  
Energy Requirements ◽  
Life Cycle Approach ◽  
Treatment Technologies ◽  
Recycling Potential ◽  
Conventional Wastewater Treatment

The term ‘green’ is nowadays widely used (and misused) in connection with many types of technologies. If a technology is ‘green’ it usually means that the technology requires less non-renewable energy sources than other alternatives. However, other parameters need to be considered as well, such as sustainability, recycling potential, treatment capacity and potential, conservation of ecosystems, etc. In this paper the energy requirements and nutrient recycling potential of constructed wetlands and wastewater aquaculture facilities are compared with that of conventional wastewater treatment technologies. The energy requirements of constructed wetlands are very low, but if significant reuse of nutrients is included (aquaculture), the energy requirements increase significantly and usually beyond the energy equivalent of the biomass produced. This is especially true in cold temperate climates where the aquaculture systems need to be housed in heated greenhouses and artificial light must be provided to secure operation throughout the year. In countries where fresh water itself is a limiting resource and where the economic capability may limit the use of artificial fertilisers, the reuse potential of wastewater may be more important. The potential for sustainable cropping of the plant biomass is excellent in tropical wetlands as the plants have a high productivity and a continuous growing season. In order to evaluate in more detail the ‘greenness’ of the different wastewater treatment technologies, the life-cycle approach might be applied. However, because constructed wetlands, besides the water quality improvement function, perform a multitude of other functions such as biodiversity, habitat, climatic, hydrological and public use functions, methodologies need to be developed to evaluate these functions and to weigh them in relation to the water quality issues.

Constructed wetland for water quality improvement: a case study from Taiwan

2010 ◽  
Vol 62 (10) ◽  
pp. 2408-2418 ◽  
Author(s):  
C. Y. Wu ◽  
J. K. Liu ◽  
S. H. Cheng ◽  
D. E. Surampalli ◽  
C. W. Chen ◽  
...  
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Constructed Wetlands ◽  
Constructed Wetland ◽  
Water Reuse ◽  
Oxygen Demand ◽  
Sediment Oxygen Demand ◽  
Nucleotide Sequence Analysis ◽  
Sediment Samples ◽  
Wetland System

In Taiwan, more than 20% of the major rivers are mildly to heavily polluted by domestic, industrial, and agricultural wastewaters due to the low percentage of sewers connected to wastewater treatment plants. Thus, constructed or engineered wetlands have been adopted as the major alternatives to clean up polluted rivers. Constructed wetlands are also applied as the tertiary wastewater treatment systems for the wastewater polishment to meet water reuse standards with lower operational costs. The studied Kaoping River Rail Bridge Constructed Wetland (KRRBCW) is the largest constructed wetland in Taiwan. It is a multi-function wetland and is used for polluted creek water purification and secondary wastewater polishment before it is discharged into the Kaoping River. Although constructed wetlands are feasible for contaminated water treatment, wetland sediments are usually the sinks for organics and metals. In this study, water and sediment samples were collected from the major wetland basins in KRRBCW. The investigation results show that more than 97% of total coliforms (TC), 55% of biochemical oxygen demand (BOD), and 30% of nutrients [e.g. total nitrogen (TN), total phosphorus (TP)] were removed via the constructed wetland system. However, results from the sediment analyses show that wetland sediments contained high concentrations of metals (e.g. Cu, Fe, Zn, Cr, and Mn), organic contents (sediment oxygen demand = 1.7 to 7.6 g O2/m2 d), and nutrients (up to 18.7 g/kg of TN and 1.22 g/kg of TN). Thus, sediments should be excavated periodically to prevent the release the pollutants into the wetland system and causing the deterioration of wetland water quality. Results of polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and nucleotide sequence analysis reveal that a variation in microbial diversity in the wetland systems was observed. Results from the DGGE analysis indicate that all sediment samples contained significant amounts of microbial ribospecies, which might contribute to the carbon degradation and nitrogen removal. Gradual disappearance of E. coli was also observed along the flow courses through natural attenuation mechanisms.

Introduction to Conventional Wastewater Treatment Technologies: Limitations and Recent Advances

2021 ◽  
pp. 1-36
Keyword(s):  
Wastewater Treatment ◽  
Human Health ◽  
Efficient Method ◽  
Rapid Growth ◽  
Municipal Wastewater ◽  
Pathogenic Microorganisms ◽  
Tertiary Treatment ◽  
Inorganic Substances ◽  
Treatment Technologies ◽  
Conventional Wastewater Treatment

The rapid growth of the industries and population leads to increasing generation of industrial and municipal wastewater. This wastewater threatens directly or indirectly the human health and industrial processes. Therefore, it is necessary to develop a rapid, simple, eco-friendly, effective, and efficient method for eliminating pollutants from industrial and municipal wastewater. The wastewater treatment aims to remove pollutants including particles, organic/inorganic substances, and pathogenic microorganisms, and finally returned to the cycle. This chapter presents a brief introduction to the issue associated with municipal and industrial wastewater. Also, this chapter presents detailed information about the conventional wastewater treatment methods. Specifically, it discusses the steps involved in the wastewater treatment viz. primary, secondary, and tertiary treatment.

Experience in non-conventional wastewater treatment techniques used in the Czech Republic

2007 ◽  
Vol 56 (5) ◽  
pp. 149-156
Author(s):  
L. Felberova ◽  
J. Kucera ◽  
E. Mlejnska
Keyword(s):  
Wastewater Treatment ◽  
Czech Republic ◽  
Constructed Wetlands ◽  
Algal Bloom ◽  
Horizontal Flow ◽  
Legal Regulations ◽  
The Czech Republic ◽  
Treatment Techniques ◽  
Removal Efficiencies ◽  
Conventional Wastewater Treatment

Among the most common non-conventional wastewater treatment techniques used in the Czech Republic are waste stabilisation ponds (WSP), subsurface horizontal flow constructed wetlands (CW) and vertical flow groundfilters (GF). These extensive systems can be advantageously used for treatment of waters coming from sewerages where the ballast weighting commonly makes more than half of dry-weather flow. The monitoring was focused at 14 different extensive systems. Organics removal efficiencies were favourable (CW–82%; GF–88%); in the case of WSP only 57% due to the algal bloom. Total nitrogen removal efficiencies were 43 and 47% for WSP and GF; in the case of CW only 32% due to often occurring anaerobic conditions in filter beds. Total phosphorus removal efficiencies were 37, 35 and 22% for WSP, GF and CW, respectively. Often occurring problems are the ice-blockage of surface aerators at WSP during wintertimes, the pond duckweed-cover or the algal bloom at WSP during summers; a gradual colmatage of filter systems; and the oxygen deficiency in beds of subsurface horizontal flow constructed wetlands. Czech legal regulations do not allow treated wastewater disposal into underground waters. There is only an exception for individual family houses. Up to now, knowledge gained by monitoring of a village (which uses the infiltration upon a permission issued according to earlier legal regulations) have not shown an unacceptable groundwater quality deterioration into the infiltration areas.

Conventional Wastewater Treatments

2020 ◽  
pp. 220-259
Keyword(s):  
Wastewater Treatment ◽  
Biological Processes ◽  
Organic Loading ◽  
Nutrient Contents ◽  
Industrial Activities ◽  
Treatment Technologies ◽  
Aerobic And Anaerobic ◽  
Conventional Wastewater Treatment

Conventional wastewater treatment consists of chemical, biological, physicochemical, and mechanical processes to remove organic loading, solids, and nutrient contents from wastewater. Biological processes are more commonly used in wastewater treatment as secondary or tertiary treatments, as it is more effective and more economical than chemical and mechanical processes. In this chapter, several types of wastewaters generated from municipal or industrial activities are discussed. Wastewater has different pollutant contents depending on the point of generation which consequently requires different ways of treatment. Some commonly used conventional wastewater treatment technologies are introduced. A particular focus is given to both aerobic and anaerobic treatments.

Using a constructed wetland for non-point source pollution control and river water quality purification: a case study in Taiwan

2010 ◽  
Vol 61 (10) ◽  
pp. 2549-2555 ◽  
Author(s):  
C. Y. Wu ◽  
C. M. Kao ◽  
C. E. Lin ◽  
C. W. Chen ◽  
Y. C. Lai
Keyword(s):  
Water Quality ◽  
Wastewater Treatment ◽  
Quality Improvement ◽  
Point Source ◽  
River Water ◽  
Constructed Wetlands ◽  
Constructed Wetland ◽  
River Water Quality ◽  
Water Quality Improvement ◽  
Wetland System

The Kaoping River Rail Bridge Constructed Wetland, which was commissioned in 2004, is one of the largest constructed wetlands in Taiwan. This multi-function wetland has been designed for the purposes of non-point source (NPS) pollutant removal, wastewater treatment, wildlife habitat, recreation, and education. The major influents of this wetland came from the local drainage trench containing domestic, agricultural, and industrial wastewaters, and effluents from the wastewater treatment plant of a paper mill. Based on the quarterly investigation results from 2007 to 2009, more than 96% of total coliforms (TC), 48% of biochemical oxygen demand (BOD), and 40% of nutrients (e.g. total nitrogen, total phosphorus) were removed via the constructed wetland system. Thus, the wetland system has a significant effect on water quality improvement and is capable of removing most of the pollutants from the local drainage system before they are discharged into the downgradient water body. Other accomplishments of this constructed wetland system include the following: providing more green areas along the riversides, offering more water assessable eco-ponds and eco-gardens for the public, and rehabilitating the natural ecosystem. The Kaoping River Rail Bridge Constructed Wetland has become one of the most successful multi-function constructed wetlands in Taiwan. The experience obtained from this study will be helpful in designing similar natural treatment systems for river water quality improvement and wastewater treatment.

Introduction to Conventional Wastewater Treatment Technologies: Limitations and Recent Advances

2021 ◽  
pp. 1-36
Keyword(s):  
Wastewater Treatment ◽  
Human Health ◽  
Efficient Method ◽  
Rapid Growth ◽  
Municipal Wastewater ◽  
Pathogenic Microorganisms ◽  
Tertiary Treatment ◽  
Inorganic Substances ◽  
Treatment Technologies ◽  
Conventional Wastewater Treatment

The rapid growth of the industries and population leads to increasing generation of industrial and municipal wastewater. This wastewater threatens directly or indirectly the human health and industrial processes. Therefore, it is necessary to develop a rapid, simple, eco-friendly, effective, and efficient method for eliminating pollutants from industrial and municipal wastewater. The wastewater treatment aims to remove pollutants including particles, organic/inorganic substances, and pathogenic microorganisms, and finally returned to the cycle. This chapter presents a brief introduction to the issue associated with municipal and industrial wastewater. Also, this chapter presents detailed information about the conventional wastewater treatment methods. Specifically, it discusses the steps involved in the wastewater treatment viz. primary, secondary, and tertiary treatment.

Conventional wastewater treatment technologies

2021 ◽  
pp. 47-75
Author(s):  
Supriya Gupta ◽  
Yamini Mittal ◽  
Rupobrata Panja ◽  
Kalp Bhusan Prajapati ◽  
Asheesh Kumar Yadav
Keyword(s):  
Wastewater Treatment ◽  
Treatment Technologies ◽  
Conventional Wastewater Treatment

scholarly journals Quantifying the Log Reduction of Pathogenic Microorganisms by Constructed Wetlands: A Review

Proceedings ◽  
2019 ◽  
Vol 48 (1) ◽  
pp. 9
Author(s):  
Sotirios Paraskevopoulos ◽  
Patrick Smeets
Keyword(s):  
Wastewater Treatment ◽  
Case Studies ◽  
Constructed Wetlands ◽  
Water Reuse ◽  
Fecal Coliforms ◽  
Operational Parameters ◽  
Pathogen Removal ◽  
Knowledge Gaps ◽  
Climatic Zones ◽  
Conventional Wastewater Treatment

Over the last 30 years, constructed wetlands (CWs) have been used as an alternative, cost-efficient way of treating wastewater, often in combination with conventional wastewater technologies. When CWs are attached at the end of conventional wastewater treatment plants, they treat the effluent and thus provide a polishing step. However, recent studies have shown that when CWs are used as the main wastewater treatment method for the agricultural reuse of effluents, they perform poorly on meeting the accepted limit of microbial contamination. Moreover, CWs are increasingly used within the scope of the circular economy and water reuse applications. Therefore, there is a need for a comprehensive exploration of the performance of CWs on pathogen removal. This paper explores relevant case studies regarding pathogen removal from constructed wetlands to create a comprehensive dataset that provides a complete overview of CWs performance under various conditions. After a systematic literature review, a total of 48 case studies were qualified for both qualitative and quantitative analyses. From the dataset, the general performance, optimal conditions, and knowledge gaps were identified. The review confirmed that constructed wetlands (as a standalone treatment) cannot meet the accepted limits of pathogen removal. However, they can be a credible choice for wastewater polishing when they are combined with conventional wastewater treatment systems. Regarding the most common indicators that were recorded, the removal of Escherichia coli ranged between 0.01–5.6 log; the removal of total and fecal coliforms was 0.2–5.32 log and 0.07–6.08 log, respectively; while the removal of fecal streptococci was 0.2–5.2 log. The great variability of pathogen removal indicates that the complexity of CWs makes it difficult to draw robust conclusions regarding their removal efficiency. Potential correlations were identified between influent and effluent concentrations, as well as between log removal and hydraulic characteristics. Additionally, no correlations between pathogen removal and temperature/climatic zones were found since average pathogen removal per country showed high variation throughout the various climatic zones. The dataset can be used as a benchmark of CWs’ performance as a barrier against the spreading of pathogens in the environment. The knowledge gaps identified in this review can provide direction for further research. Finally, a potential meta-analysis of the dataset using statistical analysis can pave the way for a better understanding of the design and operational parameters of CWs in order to fine-tune and quantify the factors that influence the performance of these systems.

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