Water Quality In Tanks Research Articles

Fuzzy Logic Harmony in Water: Mamdani Inference System Applied to Evaluate Pristine Pond Water Quality

Aquatic ecosystems that are subject to urbanization and environmental changes, such as the Kapaleeswarar and Chitrakulam tanks, depend on evaluating water quality. Their complicated data present challenges for conventional approaches. The usefulness of the Mamdani fuzzy inference system in determining the water quality in these tanks is investigated in this work. It creates a comprehensive assessment based on subject-matter expertise by handling ambiguous descriptors with linguistic variables and fuzzy sets. The system’s procedures for implementation are described in detail, with an emphasis on how well they can manage interrelated variables. The study shows how well the system measures the water quality in tanks and suggests ways to improve it. Tank evaluation that incorporates the Mamdani system encourages comprehensive resource management and cultural preservation.

Analysis of the Evolution of Water Quality in Tanks According to the Connections and Operation Mode: Application to the Most Suitable Design

The analysis and simulation of water quality in distribution networks is a complex issue of great concern today. The analysis of the evolution of water age as a simple indicator of water quality in the network is of great interest in both the design and operation phases. Understanding the factors that have the strongest influence on water quality is key to developing adequate strategies aimed at preserving it. This paper first analyses the factors with the biggest influence on the tank’s water age to support the selection of the most appropriate configuration from the point of view of water quality during design phases. Then, the main considerations when modelling tanks following the different mixing models considered in Epanet are presented. Also, real tank behaviour is characterised through field measurements and Epanet simulations in order to determine the best-fitting mixing model.

Water quality and microecosystem of water tanks in karst mountainous area, Southwest China.

Karst mountainous areas in Southwest China, the world's largest bare karst area, are faced with growing water shortages. Rainwater harvesting plays an important role in alleviating water shortage. However, there remains a substantial gap in the research regarding the water quality of tanks. Water samples were seasonally collected from ten tanks to investigate the physicochemical properties, microbial communities, and their key influencing factors. The result showed that pH, turbidity, chroma, DOC, and CODMn exceeded drinking water guidelines. The alkaline pH value and the deterioration of sensory properties was the main feature of tank water, from which the over-standard rate of the uncleaned water tanks was higher. Moreover, principal component analyses suggested that tank water quality was influenced by human activities, catchment areas, and material cycling processes within the tanks, of which in-tank microbial activities were the most important driving factors in water quality variation. Proteobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria, Firmicutes, and Verrucomicrobia were the predominant bacterial phyla in water tanks. Acinetobacter, Cyanobium-PCC-6307, CL500-29-marine-group, Candidatus-Aquiluna, and Exiguobacterium were the most abundant genera. The bacterial communities were significantly affected by the management practices. Higher relative abundance of Cyanobacteria and lower relative abundance of Proteobacteria was detected in the uncleaned tanks, which was a sign of tank water quality deterioration. The microbial community structure was closely related to the environmental factors. There was evidence that the water quality was affected by the existence of a microecosystem dominated by photosynthetic microorganisms in the water tanks. In addition, Acinetobacter, Enterobacter, Pseudomonas, and Legionella identified as the potential opportunistic pathogenic genera were frequently detected but the relative abundances except Acinetobacter were low in the tanks. Overall, our findings indicated that management style influences water quality and bacterial communities of tank water.

Synergistic Combination of Plants and Microbial-Rich Substrates Improves Water Quality in an Integrated Plant-Substrate System

Nutrient enrichment is one of the main reasons causing water quality deterioration and eutrophication in aquaculture systems, such as tanks, ponds, and natural water bodies where cage aquaculture is located. The integration of aquatic plants and substrates synergistically utilises nutrients for the development of biofilm and plant growth, thus improving the water quality in tanks. The experiment was performed in three trials to assess the use of commercial plants integrated with substrates in enhancing nutrient removal in nutrient-enriched mesocosms. Among the plants, the combination of water spinach and lemon basil exhibited significantly higher (P < 0.05) nutrient removal without causing adverse effects on plant growth when compared to the other treatments. For the substrates, the lava rock and bamboo showed the highest (P < 0.05) periphyton development and productivity. The integration of water spinach and lava rock resulted in the highest (P < 0.05) nutrient removal and plant relative growth rates indicating the positive effects of synergistic interaction between plants and microbial-periphyton colonised substrates. A total of 27 bacterial phyla (mainly non-pathogenic) were identified in the integrated water spinach and lava rock substrate treatment. Microbial community structure analysis showed that Proteobacteria, Planctomycetota, Verrucomicrobiota and Bacteroidota were the main groups found in water, roots of water spinach, and substrates. The highest (P < 0.05) bacterial diversity was observed in the substrates, followed by plant roots and water. This study illustrated that the water quality could be significantly improved by integrating suitable plants and microbial-periphyton colonised substrates in tanks.

Design And Development Of A Quality And Quantity Water Monitoring System For Water Tank Based On Internet Of Things

In the context of urban life, the quality and quantity of water stored in tanks play an indispensable role. However, concerns over the lack of effective monitoring of water conditions in tanks have garnered significant attention. This research aims to design a monitoring system utilizing Internet of Things (IoT) technology to ensure continuous monitoring of water quality and quantity within tanks.
 The study zeroes in on developing a solution that overcomes the limitations of traditional methods, known for their time and cost constraints. This solution hinges on a real-time monitoring system that integrates sensors and the NodeMCU ESP32 microcontroller. Measurements of water quality parameters, such as turbidity and total dissolved solids (TDS), along with assessments of water quantity through tank volume, are integrated into the system. Software development is carried out using the Arduino IDE platform.
 Through this research, an increased awareness of the importance of monitoring water quality in tanks is anticipated, and this solution is expected to make a significant contribution to the development of efficient and effective monitoring technology. Thus, a crucial step toward more accurate and up-to-date water monitoring in urban environments can be achieved.

IOT Monitoring Systems in Fish Farming Case Study:” University of Rwanda Fish Farming and Research Station (Ur-FFRs)”

Purpose: Fish farming refers to the farming of aquatic organisms such as fish. It involves cultivating freshwater and saltwater populations under controlled conditions. The purpose of this research is to provide a solution to the fish farmer by developing an application that would be easy to monitor water quality during the fish farming process. This will help the fish farmers to intervene timely, and therefore increase their production. The design and implementation of IoT Monitoring Systems in Fish farming helps to observe the farming system remotely by using different sensors for the water parameters. The research focused on developing a system for real time monitoring of culture tank water quality as a proof of concept and testing the basic functionalities of the system.
 Methodology: The research adopted the Rapid application methodology, which was deemed best due to its iterative approach to applications development as it also delivers systems faster at a lower cost in time-constrained projects. This methodology was suitable for our research given the time constraints in developing the application. Secondary data was used to determine the water quality aspects that require monitoring. Interviewing the operators of the culture tank also provided information on what should be incorporated in the model. by developing an application that would be easy to monitor water quality during the fish farming process. The application dashboard is the graphical user interface that the users shall use to interact with application components.
 Findings: This research proposes a solution, which is a real-time culture tank (hatchery) water quality-monitoring model, which utilizes a web application that shall be adopted by the staff of the University of Rwanda Fish Farming and Research Station and farmers. The model utilizes the IoT concept, which enables information gathering about water quality through the corresponding sensors. The status of the water quality aspects shall then be relayed on a real-time basis through a cloud platform. The farmer can then act based on the information provided, or the model can act on the farmer's behalf based on predetermined actions. The model's data can be extracted and analysed in a variety of different ways.
 Recommendations: This research contributed in developing a technological solution for real time monitoring water quality aspects of culture tank (hatchery) that can be adopted by fish farmers in Rwasave Fish Farming and Research Station by providing them with real time data whenever they are within or away from the culture tank (hatchery) site. This helps to eliminate or minimize the risk of losing fish and wastages due late interventions.it was validated by supervisors of the project.

Smart Aquarium Monitoring System Using IoT

The automatic system that is coordinated with the smart aquarium monitoring system is Fish aquarium maintenance which is a laborious procedure that must be set up and maintained correctly if you want your pet fish to have a long life. As a result, it's crucial to keep an eye on the aquarium's conditions and raise the micro aquarium tank's water quality. Fish need special circumstances such as an appropriate range of temperature, pH, and oxygen, and they demand the utmost care. To maintain its health, the aquarium where they are maintained needs to have sufficient monitoring settings. Automatic indicators for pH, dissolved oxygen level, and fish feed motor temperature are among the parameters. They are accessible through a database that holds the values generated by the indicators, and we can connect the database to an IoT mobile application we have developed to access them via the mobile device. This lessens the work and mistakes made by people when maintaining an aquarium full of aquatic creatures and avoid odd fish deaths.

Survey of float tank operating practices

Abstract Float tanks are recreational water baths with high concentrations of MgSO4 used for sensory deprivation. Documentation on standard operating practices within float tank facilities is lacking, which is useful for understanding the need for regulation. The goal of this study was to explore typical float tank operating practices by issuing a questionnaire to US float facilities on water treatment, testing, replacement and other maintenance methods. The survey was completed by 45 float tank operators across the US. Results show a spectrum of operating practices across float tank facilities and operational and risk distinctions from swimming pools and spas. To date, only one case of Pseudomonas aeruginosa associated with float tank use, and one outbreak associated with exposure to an art exhibition mimicking a float tank, have been published. Although float tanks pose a lower risk to users than swimming pools, they still pose some risk and health authorities should consider licensing float facilities. Knowledge gaps in float tank water quality best management practices were also observed. Most facilities use micron bag filtration, yet the contaminant removal efficacy of these systems is understudied. Additionally, more research is needed exploring chlorine, pH and alkalinity test kit accuracy in water with MgSO4.

Assessment of Chemical Retention of Riparian Area (Thaulla) in a Small Tank: A Study in Kankanam Tank, Weeraketiya, Sri Lanka

The agriculture sector in Sri Lanka utilizes a considerable amount of land cover (27,400 km2), allowing a significant contribution to the national economy. Most of these agricultural fields are cultivated via irrigation schemes, especially in the Dry Zone of Sri Lanka, which receives limited rainfall throughout the year. In ancient days, communities in these areas used their techniques to develop tanks as a strategy to store and conserve the rainwater. The riparian area or “Thaulla” located in the upper peripheral region of the tank, is one of the basic and vital components that help filter nutrient pollutants and sediments in the water inflow of the tank. This study aimed to assess the chemical retention of Thaulla in a small tank viz. Kankanam tank, located in Hambantota District in Sri Lanka. The extent in the Thaulla area of the selected tank is about 2,185.3 m2. Surface soil (0-30 cm) samples from eleven locations within the Thaulla area and water samples from three tank locations were collected randomly. As the control, typical soil samples near the sampling site were collected. These samples were tested using standard methods for nine parameters: pH, EC, NO3--N, NH4+-N, Total N, P, Na, K, and Ca. ArcMap Software prepared a spatial distribution map for each parameter to identify their spatial variations in the studied area. Results revealed that concentrations of nutrients in Thaulla area were high compared to the typical soil and water in the tank indicating that it was highly contributed to retaining chemicals such as P (29.88 ppm), Ca (447.55 ppm), Na (5.14 ppm), and K (4.17 ppm). According to the spatial variation, it was noted that various external sources around the tank influenced the nutrient retention in the Thaulla area. The nutrient retention was high in the areas, closer to the landfills, paddy fields, and leachate canals. Further, the functionality of the Thaulla area as a constructed wetland could be identified. The tank water quality was satisfied with the tested parameters and in accordance with the irrigation water quality guidelines. Therefore, the Thaulla/riparian area is an important component of a tank allowing substantial chemical retention to control the pollution of water in the tank. Further studies need to be conducted to understand the seasonal variation of the chemical retention in Thaulla area.
 Keywords: Constructed wetland, Riparian area, Small tank, Soil parameters, Water quality parameters

Cascade Tank Water Quality Management: A Case Study in Thirappane Tank Cascade System, Sri Lanka

Tank cascade system (TCS) is a series of tanks located in a mesocatchment and has been accepted as a Globally Important Agricultural Heritage System found in Sri Lanka. Ecosystem components of the TCS play a major role in purifying water within the system. This study attempted to investigate the water quality status and the farmers’ willingness to rehabilitate the ecosystem components of the Thirappane TCS. Drinking and irrigation water quality parameters were tested in 34 locations and drinking and irrigation water quality indexes were calculated. Participatory rural appraisal and a questioner survey were conducted to gather social data. Water of TCS was observed to be appropriate for irrigation but not for drinking during the Maha cropping season. Based on the results of the Nitrate (as NO3 - ) and Total Phosphate (as PO4 3-), water of TCS can be categorized as eutrophic. Presence of ecosystem features of tank cascade system, annual income of the respondents, satisfaction on the quality of water for drinking, and the awareness about the tank cascade system significantly influenced the participatory decisions of the community on the rehabilitation of TCS. This study shall be an example and an eye opener to formulate sustainable tank cascade management plan.

Wood and sulfur-based cyclic denitrification filters for treatment of saline wastewaters

This study investigated the performance and microbiome of cyclic denitrification filters (CDFs) for wood and sulfur heterotrophic-autotrophic denitrification (WSHAD) of saline wastewater. Wood-sulfur CDFs integrated into two pilot-scale marine recirculating aquaculture systems achieved high denitrification rates (103 ± 8.5 g N/(m3·d)). The combined use of pine wood and sulfur resulted in lower SO42− accumulation compared with prior saline wastewater denitrification studies with sulfur alone. Although fish tank water quality parameters, including ammonia, nitrite, nitrate and sulfide, were below the inhibitory levels for marine fish production, lower survival rates of Poecilia sphenops were observed compared with prior studies. Heterotrophic denitrification was the dominant removal mechanism during the early operational stages, while sulfur autotrophic denitrification increased as readily biodegradable organic carbon released from wood chips decreased over time. 16S rRNA-based analysis of the CDF microbiome revealed that Sulfurimonas, Thioalbus, Defluviimonas, and Ornatilinea as notable genera that contributed to denitrification performance.

Polyculture culture of black tiger shrimp Penaeus monodon and red seaweed Gracilaria tenuistipitata under different densities: effects on water quality, post-larvae performance and their resistance against Vibrio parahaemolyticus

The integration of seaweeds (extractive, low-footprint species) into aquaculture systems has been considered an alternative approach for the sustainable development of the shrimp industry, which aims to expand in an environmentally friendly way. Two consecutive experiments were conducted to evaluate the effects of integrating various densities of black tiger shrimp Penaeus monodon post-larvae (PL) and red seaweed Gracilaria tenuistipitata on water quality and shrimp performance in the nursery phase. The first experiment involved a 3 × 4 factorial design with three levels of shrimp density (1000; 2000 and 3000 PL m−3) and four levels of red seaweed density (0, 1.0, 1.5 and 2.0 kg m−3) randomly allocated in triplicate tanks for 30 days. Shrimp PL (with a mean weight of 0.012 ± 0.002 g and length of 1.12 ± 0.09 cm) and red seaweed were reared in 150 L tanks at a salinity of 15 g L−1. Significant synergistic effects between shrimp and seaweed densities were observed for the NO3− total nitrogen (TN) and PO43− contents, as well as for the survival (p < 0.05) and production of shrimp (p < 0.01). The integration of shrimp and red seaweed significantly decreased the concentrations of nitrogen and phosphorus in the rearing tanks and greatly enhanced the survival and growth rate of shrimp. In particular, increased stocking density resulted in poorer growth performance but enhanced production. Applying stocking densities of 1000 and 2000 PL m−3 obtained larger shrimp size, while a density of 3000 PL m−3 achieved the highest production output in the integrated system. In the second experiment, which followed the 30-day growth trial, shrimp quality was assessed via an immersion challenge test using pathogenic Vibrio parahaemolyticus (a concentration of 2 × 108 CFU mL−1) on the shrimp groups previously stocked at a density of 3000 PL m−3 and integrated with different quantities of seaweed. After 14 days of challenge, the cumulative mortality in the monoculture system averaged 75.6%, which was significantly higher (p < 0.05) than those in the integrated groups (17.8–31.1%). It is concluded that the integration of P. monodon shrimp and G. tenuistipitata improved tank water quality as well as shrimp survival and growth while also enhancing the antibacterial activity of shrimp against V. parahaemolyticus infection in the nursery phase.

The Effect of Goldfish (Carassius auratus) on Water Quality in Horse Stock Tanks

Goldfish (Carassius auratus) have been reported as a method to keep water tanks clean; however, little information exists on this approach. The objectives were to evaluate the efficacy of goldfish on maintaining water quality in tanks and to evaluate the frequency that this method is used. The first objective was completed during June through October 2017 in St. Paul, MN, using plastic and metal 379 L stock tanks, each with and without goldfish in a drylot that housed six adult horses. The stocking rate was 5 goldfish per tank. Daily readings of total dissolved solids (TDS) and water turbidity (NTU), and weekly samples to measure chlorophyll a were taken. At the end of each 28-day period, tanks were cleaned and rotated. Plastic tanks had lower TDS than metal tanks (P < .001); however, metal tanks had lower NTU and chlorophyll a (P ≤ .008). Adding goldfish resulted in lower TDS (P < .001); however, there was no effect on NTU or chlorophyll a (P ≥ .097). No parameters had an impact on horse preference (P ≥ .108). The second objective was completed using an online survey that was open from October 31 until December 15, 2018. Of the 672 completed surveys, 56% had not tried using goldfish in water tanks, 26% had utilized goldfish in the past, and 18% currently used goldfish. The inclusion of goldfish in water tanks did not affect all water quality parameters; however, 44% of survey respondents had tried, or were currently using, this management method.

Assessing the Effects of Grass Carp Excretion and Herbivory of Submerged Macrophytes on Water Quality and Zooplankton Communities

Grass carp (Ctenopharyngodon idella) play an important role in the ecological restoration of water bodies, and it is crucial to understand the mechanism behind this. An experiment was performed in tanks consisting of three treatments: 1) without fish (control treatment, CON), 2) with fish unable to feed on submerged macrophytes (excretion treatment, EXCR), and 3) with fish swimming free (herbivory plus excretion treatment, HERB-EXCR). Treatments were conducted with varying macrophytic compositions (Vallisneria natans (Lour.) Hara, Ceratophyllum demersum L., and both species) and carp densities (low, medium, and high: 0.15, 0.30, and 0.45 g.L-1 respectively, in EXCR and HERB-EXCR). Results indicated that in EXCR and HERB-EXCR, water quality was better with a lower density of grass carp. In EXCR, the water quality in tanks with V. natans was worse than in other tanks, and water quality in C. demersum tanks was better under the HERB-EXCR treament. Compared to EXCR, grass carp in HERB-EXCR significantly increased concentrations of NH4+-N, NO2--N, and chlorophyll a. The effects on biomasses of protozoa, copepods, and total zooplankton in HERB-EXCR were greater than in the other treatments. Integrated analysis showed that grass carp herbivory on submerged macrophytes could be the central mechanism accounting for the changes in water quality and zooplankton communities.

Suitability Analysis of Ground and Tank Water Quality for Domestic Purpose along Downstream Side of Coimbatore City

Suitability Analysis of Ground and Tank Water Quality for Domestic Purpose along Downstream Side of Coimbatore City

Evidence of Avian and Possum Fecal Contamination in Rainwater Tanks as Determined by Microbial Source Tracking Approaches.

Avian and possum fecal droppings may negatively impact roof-harvested rainwater (RHRW) water quality due to the presence of zoonotic pathogens. This study was aimed at evaluating the performance characteristics of a possum feces-associated (PSM) marker by screening 210 fecal and wastewater samples from possums (n = 20) and a range of nonpossum hosts (n = 190) in Southeast Queensland, Australia. The host sensitivity and specificity of the PSM marker were 0.90 and 0.95 (maximum value, 1.00), respectively. The mean concentrations of the GFD marker in possum fecal DNA samples (8.8 × 10(7) gene copies per g of feces) were two orders of magnitude higher than those in the nonpossum fecal DNA samples (5.0 × 10(5) gene copies per g of feces). The host sensitivity, specificity, and concentrations of the avian feces-associated GFD marker were reported in our recent study (W. Ahmed, V. J. Harwood, K. Nguyen, S. Young, K. Hamilton, and S. Toze, Water Res 88:613-622, 2016, http://dx.doi.org/10.1016/j.watres.2015.10.050). The utility of the GFD and PSM markers was evaluated by testing a large number of tank water samples (n = 134) from the Brisbane and Currumbin areas. GFD and PSM markers were detected in 39 of 134 (29%) and 11 of 134 (8%) tank water samples, respectively. The GFD marker concentrations in PCR-positive samples ranged from 3.7 × 10(2) to 8.5 × 10(5) gene copies per liter, whereas the concentrations of the PSM marker ranged from 2.0 × 10(3) to 6.8 × 10(3) gene copies per liter of water. The results of this study suggest the presence of fecal contamination in tank water samples from avian and possum hosts. This study has established an association between the degradation of microbial tank water quality and avian and possum feces. Based on the results, we recommend disinfection of tank water, especially for tanks designated for potable use. The use of roof-harvested rainwater (RHRW) for domestic purposes is a globally accepted practice. The presence of pathogens in rainwater tanks has been reported by several studies, supporting the necessity for the management of potential health risks. The sources of fecal pollution in rainwater tanks are unknown. However, the application of microbial source tracking (MST) markers has the potential to identify the sources of fecal contamination in a rainwater tank. In this study, we provide evidence of avian and possum fecal contamination in tank water samples using molecular markers. This study established a potential link between the degradation of the microbial quality of tank water and avian and possum feces.

Quality assessment and primary uses of harvested rainwater in Kleinmond, South Africa

water security, reaching the Millennium Development Goals (MDGs) and sustaining water resources. The microbial and chemical quality of RWH samples collected from tanks in a sustainable housing development in Kleinmond, South Africa, were monitored. Results indicated that the tank water quality was within all the chemical standards (cations and anions) analysed for potable water. However, the counts of the indicator organisms, for example, total coliforms and Escherichia coli, exceeded the guidelines stipulated by the Department of Water Affairs and Forestry (1996). The microbial analysis results thus indicate that the tank water was not fit for potable use without treatment. A social research project was then conducted to describe, amongst others, the condition of the tank and the users’ knowledge of the RWH system. In addition, demographic data, viz., gender, household size and employment status, etc., were gathered in order to provide a socio-economic background description of the study population. Data were gathered by means of face-to-face interviews with 68 respondents. Generally, RWH was used for washing clothes and for cleaning inside and outside the houses. This study noted that without acceptance and necessary training to maintain and use the tank optimally, it is possible that social development projects, such as the one in Kleinmond, will not be sustainable.Keywords: domestic rainwater harvesting; microbial and chemical quality; social perception; acceptance

Evaluation of Current Industry Practices for Maintaining Tomato Dump Tank Water Quality during Packinghouse Operations

Maintenance of adequate sanitizer levels in tomato dump tanks is critical to preventing pathogen survival and transfer, and internalization in the fruit. However, the rapid accumulation of organic matter in dump tanks can cause a significant decline in sanitizer concentration, thus leaving wash solutions vulnerable to becoming a reservoir for pathogens. This study investigated the dynamic changes in wash water quality and sanitizer concentration during routine operations of three medium to large tomato packinghouses in Florida in 2010 and 2011. Overall, water quality declined continuously during packinghouse operations, as exhibited by significant increases in chemical oxygen demand and turbidity. Free chlorine concentration, oxidation reduction potential and pH fluctuated largely as a consequence of periodic addition of sodium hypochlorite and citric acid, and the rapid loss of free chlorine caused by organic matter. Although the packinghouses differed significantly in system configuration, operation and chlorine dosing rates, at least 25 mg/L of free chlorine concentrations were maintained in all of the dump tanks surveyed. Practical Applications Wash water quality and sanitizer strength are important factors influencing food safety of tomatoes washed in packinghouses. Soil, debris and juices from damaged fruits entering dump tanks along with tomatoes can cause water quality and sanitizer strength to decline dramatically, leaving wash solutions vulnerable to the growth of harmful bacteria. Maintenance of adequate sanitizer levels in tomato dump tanks is critical to reducing pathogen survival, transmission and incidence of internalization in the fruit. The researchers surveyed the water quality and sanitizer concentrations during routine operations of three major tomato packinghouses in Florida in 2010 and 2011. The results are useful for the regulatory agency and tomato industry in developing packinghouse handling guidelines to maintain the quality and food safety of tomatoes.

Characterisation of retention tank water quality: particle settling velocity distribution and retention time

Retention tanks (RTs) are commonly used to reduce combined sewer overflows, management of which is an important way of reducing the impacts of urban development on receiving waters. However, overflow characteristics and the processes affecting them are not yet fully understood. In a context of integrated urban wastewater systems, the management of RTs is mainly done to satisfy hydraulic constraints even if the idea behind such structures is to limit the discharge of pollutants to the environment. This study reports new insights in the settling processes and the pollutant behaviour occurring in an off-line RT. The authors first focus on the total suspended solids (TSS) and the total chemical oxygen demand (CODt) dynamics at the inlet and the outlet of a RT. Secondly, they focus on the possible relationship between the variation of the particle settling velocity distribution of particles and the TSS concentration dynamics. Finally, analyses of the TSS and CODt concentration evolution during tank emptying give information on the interaction between wastewater retention time and the settling performance.

Quality and Quantity Monitoring of Five Rainwater Tanks in Western Sydney, Australia

AbstractRainwater tanks are a fundamental component of integrated water cycle management, but the quality of harvested water is little understood and is potentially affected by many factors such as roofing material, site temperature, frequency of tank use, and surrounding land use. There has been limited study of the first flush, overflow water and harvested water quality from rainwater tanks in Australia. This paper presents the water quality results of a yearlong data collection and analysis study involving five rainwater tanks located in Western Sydney, Australia. The results show that tank water quality was impacted by the construction materials used to fabricate both the tanks and roofs. Furthermore, the overflow and first flush water quality were found to be of a lower standard than the tank samples, with implications for the cleaning of the first flush device and overflow diversion. Finally, the issues identified with the maintenance of the tanks are highlighted and discussed.