Search Results (16)

Floods generated by rain cause significant economic and human losses. The campus of the Escuela Superior Politécnica del Litoral (ESPOL) has a drainage system that conducts stormwater to two discharge points outside the campus. The system works effectively at the macro-drainage level. However, a very crowded area is deficient at the micro-drainage level, which has registered flooding and the proliferation of vectors that affect people’s health. This work aimed to design a masterplan for stormwater sewerage by analyzing the existing situation and applying technical criteria that allow the establishment of solutions and strategies to control floods at the university campus. The methodology consisted of: (i) data collection and processing for the stormwater drainage system diagnosis; (ii) a design proposal for micro-drainage and (iii) a SWOT analysis to propose improvement strategies in water management. The resulting flows for return periods of 5 years, 10 years, and 25 years are 9.67 m³/s, 11.85 m³/s, and 15.85 m³/s, respectively. In the latter, as the most critical area (presence of flooding), the implementation of a trapezoidal channel 80.20 m long, with a capacity of 1.00 m³/s, for a return period of 25 years was proposed. The stormwater masterplan will contribute to the execution of activities within the campus and prevent accidents and the proliferation of diseases, constituting a water-management model that can be replicated locally, regionally, and internationally. Full article

Sewerage systems-related solid waste accumulates in considerable quantities in urban water systems, including rainwater drainage pipes, pumping stations, grease traps, grit chambers, and septic tanks. Traditional management methods, such as sanitary landfilling, incineration, and composting, not only endanger the environment but also consume a significant amount of land. To address this problem, a variety of waste was collected from a terminal and different facilities in sewerage systems, and the characteristics of solid waste were tested and analyzed. The corresponding appropriate approaches to resource recovery strategies were proposed in detail. The solid waste in the wastewater treatment plant (WWTP) contains low organic matter content and a certain quantity of heavy metals, making recycling difficult. Before the solid waste enters the WWTP, the strategy of pre-sorting, treating, and recycling the solid waste is worth recommending. The waste was divided into three categories based on its nature, and corresponding resource utilization strategies were proposed. A small part of solid waste that is not suitable for pre-recycling can be discharged normally and enter the WWTP for treatment. This paper provides a scientific basis for the green resource utilization of solid waste in the field of sewerage systems in developing countries. Full article

This study determined the influences of Bacillus sphaericus Laboratorium voor Microbiologie Gent (LMG) 22257 bacteria activity on mortar samples cured in various media regarding compressive strength, porosity, water absorption, and water permeability. Three types of curing media were utilized, namely distilled water (D.W.), deposition water (D.M.), and run-off water (R.W.). The compressive strength was measured using 100 mm mortar cubes. The water porosity, water absorption, and water permeability were analyzed using the Leeds permeability cell with dimensions of the mortar cylindrical specimens of 55 mm diameter and 40 mm thickness. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometry (EDX) were utilized, respectively, for microstructure analysis and quantifying the elements with atomic numbers. The results indicated the presence of calcium carbonate and more calcium silicate hydrate (CSH) depositions on bacterial mortars. The inclusion of Bacillus sphaericus LMG 22257 bacteria activity and curing media type affected mortar properties through compressive strength and durability improvements, as well as the reduction in water porosity, water absorption, and water permeability of mortar. The comparison of CaCO₃ precipitation, such as a sufficient growth nutrient requirement and hostile bacteria environment, was observed. Curing in R.W. produced the most significant bio-based cement (BBC) mortar improvement, followed by D.M. BBC curing in runoff water had a 40% improvement in strength compared to normal curing. As a conclusion, runoff water is a highly promising sufficient nutrient to bacteria for the biomineralization process to produce CaCO₃. This work also aims to apply this approach in the field, especially in sewerage and drainage systems. Full article

The increase in the frequency and intensity of hazardous hydrometeorological phenomena is one of the most dangerous consequences of climate instability. In this study, we summarize the data on severe weather phenomena using the data from 23 meteorological stations in Crimea from 1976 to 2020. Particular attention was paid to the precipitation phenomena descriptions. For the last 45 years, a significant positive trend of interannual variability of the annual occurrence of severe weather phenomena was estimated to be +2.7 cases per decade. The trend for severe precipitation phenomena was estimated to be +1.3 cases per decade. The probable maximum annual daily precipitation as a quantitative indicator of hazardous events was estimated for each station by using both the stationary and the non-stationary GEV models. For at least half of the meteorological stations, a non-stationary GEV model was more appropriate for the estimation of the precipitation extremes. An analysis of the main synoptic processes that drive severe weather phenomena of precipitation was carried out. The greatest contribution to the formation of severe precipitation was made by Mediterranean–Black Sea cyclones. At the same time, half of all of the cases of extreme precipitation were caused by cyclones generated over the Black Sea only, in all seasons apart from winter. In the mid-troposphere, four types of meridional circulation were identified depending on the location of troughs and ridges, with respect to the Black Sea region. More than 42% of severe precipitation phenomena were accompanied by an isolated high-altitude cyclone in the mid-troposphere over the Black Sea region. The main recommendation that can be drawn from this study is that long-term climatic non-stationarity should be taken into account whenever the risk assessment or hazard analysis is to be carried out. The results can also favor the designing of drainage and sewerage systems in urban areas. The findings of atmospheric patterns can be used for the improvement of extreme precipitation forecasts. Full article

In this review, hydro-technological advancements in the Hellenic world throughout the millennia are considered in relation to the scientific developments and perceptions of the natural world articulated by Greek thinkers. Starting with the advanced hydro technologies of the Minoan civilization, this review presents the state-of-the-art evaluation of the hydro technologies in Greek historical contexts. More precisely, this review focus on how, when, and where modern hydro technologies developed based on ancient technological achievements, and subsequently when technological achievements were totally forgotten in specific periods, such as the Iron Age (ca 1200–800 BC), only to be reinvented or rediscovered in subsequent periods. In most cases, information has been collected from different sources and was cross-matched with each other. The results observed from the literature and material evidence are compiled and presented in the form of a critical review study. With a few examples, comparisons to hydrologic and hydraulic developments in other civilizations are considered and discussed. Full article

Urban sanitation is a major challenge during the rapid urbanization being experienced by developing countries, as a low sewerage infrastructure capacity and irregular onsite wastewater treatment raise the risk of surface water contamination. The application of specific sewage markers to characterize contaminant sources is therefore essential for managing urban sanitation issues. In this study, we investigated the concentrations of eight sewage markers (acetaminophen, caffeine, carbamazepine, cotinine, sulfamethoxazole, sulfapyridine, atenolol, and acesulfame) in various water sources within urban area of the Galle City, Sri Lanka. The total concentration of the eight markers was in the order of hospital discharge > sewage treatment plant (STP) influent > surface drainage system. Among the eight selected markers, acetaminophen was dominant in hospital discharge (70.2–123.6 µg/L) while caffeine was the largest contributor to STP influent (16.2–68.7 µg/L) and surface drainage (0.95–21.73 µg/L). We then proposed and tested a set of criteria for evaluating the applicability of markers, including removal efficiency, concentration magnitude, excretion rate, and wastewater burden. The labile markers caffeine and acetaminophen were suitable for characterizing domestic gray and black wastewater, respectively. These results imply that the city’s drainage system receives both domestic graywater and human excretion, likely due to insufficient on-site sanitation systems. The conservative marker carbamazepine was useful for tracking hospital residues over long distances; these results imply that hospital wastewater treatment was not working properly, accounting for pharmaceutical residues reaching surface water via a hidden discharges connected to the drainage system. Full article

Nature (ecosystem) based processes for wastewater treatment include constructed wetlands (CWs), waste stabilization ponds, vegetated drainage ditches, buffer zones, instream or bankside river techniques, and mixotrophic systems, where light and CO₂ are utilized, in addition to organic carbon compounds, by algal cultures. Algae-based systems can simultaneously remove organic matter, N, and P and may offer substantial energetic advantages compared to traditional biological treatment systems, require small spatial footprint, and contribute to biofuels production and CO₂ emissions mitigation. Bioelectrochemical systems (BES) such as microbial fuel cells (MFCs) present characteristics compatible with the use in isolated realities for water and wastewater treatment with contextual energy recovery and may be combined with other nature-based process technologies to achieve good treatment and energy efficiencies. Despite that their application in real-scale plants has not been assessed yet, the most probable outcome will be the in situ/on site treatment (or pretreatment) of wastes for small “in house” plants not connected to the sewerage network. This paper focuses on the current practices and perspectives of hybrid nature-based systems, such as constructed wetlands and microalgae integrated phytoremediation plants, and their possible integration with microbial electrochemical technologies to increase recovery possibilities from wastes and positively contribute to a green economy approach. Full article

High prevalence of chronic and infectious diseases in Indigenous populations is a major public health concern both in global and Australian contexts. Limited research has examined the role of built environments in relation to Indigenous health in remote Australia. This study engaged stakeholders to understand their perceptions of the influence of built environmental factors on chronic and infectious diseases in remote Northern Territory (NT) communities. A preliminary set of 1120 built environmental indicators were systematically identified and classified using an Indigenous Indicator Classification System. The public and environmental health workforce was engaged to consolidate the classified indicators (n = 84), and then sort and rate the consolidated indicators based on their experience with living and working in remote NT communities. Sorting of the indicators resulted in a concept map with nine built environmental domains. Essential services and Facilities for health/safety were the highest ranked domains for both chronic and infectious diseases. Within these domains, adequate housing infrastructure, water supply, drainage system, reliable sewerage and power infrastructure, and access to health services were identified as the most important contributors to the development of these diseases. The findings highlight the features of community environments amenable to public health and social policy actions that could be targeted to help reduce prevalence of chronic and infectious diseases. Full article

The mechanical-biological waste treatment plants (MBTP), which include the municipal waste biogas plants, have an important role in sustainable urban development. Some plants are equipped with a sewage pre-treatment plant, which is then directed to the sewerage system and the treatment plant. Others, on the other hand, have only a non-drainage tank. The parameters of technological sewage (TS) or processing technology could reduce sewage contamination rates. In addition to the quality of sewage from waste treatment plants, the emission of odours is also an important problem, as evidenced by the results obtained over the sewage pumping station tank. The conducted statistical analysis shows a significant positive correlation between odour concentration (c_od) and volatile organic compounds (VOCs). Analysing the individual compounds, a high positive correlation was also found—the strongest being between H₂S, NH₃ and VOCs. In the case of sewage compounds, the insignificant correlation between P total and other parameters was found. For the rest of the compounds, the highest positive correlation was found between COD and BOD and N-NO₂ and N-NH₃ as well as COD and N-NO₂. The dilution of sewage is only an ad hoc solution to the problem. Further work should be aimed at reducing sewage pollution rates. The obtained results indicate large pollution of technological sewage and a high level of odour and odorants concentration. The novelty and scientific contribution presented in the paper are related to analyses of various factors on technological sewage parameters and odour and odorant emission from TS tank at biogas plant processing municipal waste, which may be an important source of knowledge on the management of TS, its disposal and minimisation of emitted compound emissions. Full article

Water and sewage management in Poland has systematically been transformed in terms of quality and quantity since the 1990s. Currently, the most important problem in this matter is posed by areas where buildings are spread out across rural areas. The present work aims to analyse the process of changes and the current state of water and sewage management in rural areas of Poland. The author intended to present the issues in their broader context, paying attention to local specificity as well as natural and economic conditions. The analysis led to the conclusion that there have been significant positive changes in water and sewage infrastructure in rural Poland. A several-fold increase in the length of sewage and water supply networks and number of sewage treatment plants was identified. There has been an increase in the use of water and treated sewage, while raw sewage has been minimised. Tap-water quality and wastewater treatment standards have improved. At the same time, areas requiring further improvement—primarily wastewater management—were indicated. It was identified that having only 42% of the rural population connected to a collective sewerage system is unsatisfactory. All the more so, in light of the fact that more than twice as many consumers are connected to the water supply network (85%). The major ecological threat that closed-system septic sewage tanks pose is highlighted. It is pointed out that they are mainly being replaced by household wastewater treatment systems with ineffective filtering drainage. Furthermore, recommendations were also made for the future development of selected aspects of water and sewage management, including the legal and the political. Full article

The main source of water to the peri-urban areas of Bengaluru is groundwater. Access to groundwater is through tankers, private borewells, Bruhat Bengaluru MahanagaraPalike (Urban Local Body) borewells, and public stand posts. All modes other than tankers provide water to the community free of charge. Reclaimed water from sewage treatment plants (STPs) is in use by industries and some gated communities and multistoried apartments for toilet flushing and landscaping. For individual households in peri-urban areas of Bengaluru, it could be an additional water source replacing expensive water supply through tankers; reducing demand for groundwater (a finite resource); improving the sanitation system by providing drainage systems and preventing groundwater contamination from black and grey water. Consequently, this research paper investigates the willingness of residents in peri-urban areas of Bengaluru to use reclaimed water for non-potable end uses. To investigate residents’ willingness and key motivations for the use of reclaimed water, a survey of residents in the peri-urban ward of Bellandur was conducted. In this region, the sewerage board had prepared a media advertisement to create awareness of—and to sell—reclaimed water to other users, including local residents. This advertisement was shown to respondents, asking if they were willing to accept and buy the reclaimed water at 15 Indian Rupees (INR) per kiloliter. Sixty-seven percent of residents who were household owners were willing to buy reclaimed water, 20% were concerned about hygiene, and 33% of respondents lacked trust in the public agency with respect to water quality standards. The study concludes that public awareness from key stakeholders is essential for the reuse of reclaimed water. It also recommends stringent regulation by levying fees for groundwater extraction in addition to making reclaimed water readily available and supplied free of charge to the consumers. In addition, the quality of reclaimed water should meet international standards to gain the confidence of the people. Full article

Although Sustainable Drainage Systems (SuDS) are used in cities across the world as effective flood adaptation responses, their economic viability has frequently been questioned. Inclusion of the monetary value of ecosystem services (ES) provided by SuDS can increase the rate of return on investments made. Hence, this paper aims at reviewing the enhancement of the economic value of large-scale investments in SuDS through inclusion of ecosystem services. This study focuses on the flood reduction capacity and the ES benefits of green roofs and rain barrels in the combined sewerage network of Montevideo Municipality in Uruguay. The methodology comprises a cost–benefit analysis—with and without monetised ES provided by SuDS—of two drainage network configurations comprising: (i) SuDS; and (ii) SuDS and detention storage. The optimal drainage design for both these drainage configurations have been determined using SWMM-EA, a tool which uses multi-objective optimisation based evolutionary algorithm (EA) and the storm water management model (SWMM). In both design configurations, total benefits comprising both flood reduction and ES benefits are always higher than their costs. The use of storage along with SuDS provides greater benefits with a larger reduction in flooding, and thus is more cost-effective than using SuDS alone. The results show that, for both of the drainage configurations, the larger investments are not beneficial unless ES benefits are taken into account. Hence, it can be concluded that the inclusion of ES benefits is necessary to justify large-scale investments in SuDS. Full article

This paper presents a critical review of the physical impacts of decentralized water supply systems on existing centralized water infrastructures. This paper highlights the combination of centralized and decentralized systems, which is referred to as hybrid water supply systems. The system is hypothesized to generate more sustainable and resilient urban water systems. The basic concept is to use decentralized water supply options such as rainwater tanks, storm water harvesting and localized wastewater treatment and reuse in combination with centralized systems. Currently the impact of hybrid water supply technologies on the operational performance of the downstream infrastructure and existing treatment processes is yet to be known. The paper identifies a number of significant research gaps related to interactions between centralized and decentralized urban water services. It indicates that an improved understanding of the interaction between these systems is expected to provide a better integration of hybrid systems by improved sewerage and drainage design, as well as facilitate operation and maintenance planning. The paper also highlights the need for a framework to better understand the interaction between different components of hybrid water supply systems. Full article

Although there is evidence of surface-based storm drainage systems in early Babylonian and Mesopotamian Empires in Iraq (ca. 4000–2500 BC), it is not until after ca. 3000 BC that we find evidence of the well organized and operated sewer and drainage systems of the Minoans and Harappans in Crete and the Indus valley, respectively. The Minoans and Indus valley civilizations originally, and the Hellenes and Romans thereafter, are considered pioneers in developing basic sewerage and drainage technologies, with emphasis on sanitation in the urban environment. The Hellenes and Romans further developed these techniques and greatly increased the scale of these systems. Although other ancient civilizations also contributed, notably some of the Chinese dynasties, very little progress was made during the Dark ages from ca. 300 AD through to the middle of the 18th century. It was only from 1850 onwards that that modern sewerage was “reborn”, but many of the principles grasped by the ancients are still in use today. This paper traces the development of the sewer from those earliest of civilizations through to the present day and beyond. A 6000 year technological history is a powerful validation of the vital contribution of sewers to human history. Full article

Pluvial flooding already challenges the capacity of drainage and sewerage system in urban areas in Scandinavia. For system owners this requires a stricter prioritization when improving the systems. Experts seem to agree that a regime shift from improving old combined sewers by piped solutions to more sustainable drainage systems (SuDS), must take place. In this paper results from an investigation amongst the largest cities in Norway, Denmark and Sweden concerning drivers and preferred methods for improving the old system are presented. The results indicate that Norway ranks flood prevention lower than the other Scandinavian countries. During the last decades, Norwegian authorities have had a strong focus on pollution from wastewater treatment plants (WWTP). The attention to drainage and sewerage system regarding flooding, water leaks, infiltration or pollution has been neglected. Renewal or rate of investment in relation to existing drainage and sewerage system is easy to register, and provides a measure of the activity. In order to optimize flood prevention, and may be promoting the use of SuDS, the cities should be required to measure the efficiency, either by monitoring or modeling the impact of stormwater to the system. Lack of such requirements from Norwegian authorities seem to be a plausible explanation to why Norwegian cities are less focused on flood prevention compared to Swedish and Danish cities. Full article