Strengthening of Sewerage Systems with Composites Plates:Numerical Optimization

Sewerage systems are subject to many types of degradation. In France, an estimated 10% of the total systems length requires work due to structural degradation. At present, there is no method to localised rehabilitation of man-entry sewers. Laboratory tests have validated localised methods that involve bonding composite plates to the sewer. Those tests were performed on pre-damaged (multi-cracked) ovoid test pieces. The degradation observed was a longitudinal crack opened at the crown. The tests were performed under vertical loading. Our Study concerns the application of partial lining of sewer with composites plates. The composite strengtheners used were 1.2 mm thick pultruded carbon plates. A series of experiments were carried out on reinforced-concrete ovoids (T180) strengthened and unstrengthened by carbon plates in the keystone. After this test, a vertically-loaded ovoid was subjected to three-dimensional modelling in order to determinate its structural behavior and collapse mechanism. Knowledge of the latter make it possible to limit the areas in need of strengthening. An ovoid strengthened by composite plates adhered to the damaged areas was also modelled. Using real case data, modelling was carried out using a finite-element computational software program. This program allows cracking to be monitored until the structure collapses. Many conventional approaches using intensity factors k and contour integrals J have already been reported in the literature. We used methods for restituting energy G. Because nonlinear elasticity was being calculated, the constitutive laws of the various materials had to be taken into account. These constitutive laws describe the evolution of the materials. Moreover, those laws are subject to deformation limits. The simulated models were homogeneously meshed with physically nonlinear, triangular elements. The test results were then compared to those of the digital models. Partial lining of a sewer with composite plates, compared to a traditional reinforced-concrete lining, achieves a cost reduction of about 55%.

Estimation and optimization operation in dealing with inflow and infiltration of a hybrid sewerage system in limited infrastructure facility data

Inflow and infiltration （I/I） are serious problems in hybrid sewerage systems. Limited sewerage information impedes the estimation accuracy of I/I for each catchment. A new method dealing with I/I of a large-scale hybrid sewerage system with limited infrastructure facility data is proposed in this study. The catchment of representative pump stations was adopted to demonstrate the homological catchments that have similar wastewater fluctuation characteristics. Homological catchments were clustered using the self-organizing map （SOM） analysis based on long-term daily flow records of 50

Urban Stormwater and Sewerage Modelling: An Approach for Peak Runoff and Volume Assessment

In this study, an integrated approach for runoff estimation using the storm water management model (SWMM) was applied to undertake a stormwater and sewerage modelling in urban setting. The main objectives of the research and this manuscript include overload detection of sewer systems during extreme rainfall events with SWMM and to model and predict the relationship between precipitation parameters and overflooding of sewer collection system that includes emergency ponds to relieve flow from pump stations. The study takes into account monitored concurrent extreme rainfall event data and peak wet weather flows observed at outfall of collection system entering a wastewater treatment plant draining the urban centre. In the study SWMM was modified and adapted for the Tati and Ntshe confluence rivers draining the urban centre of Francistown in Northern Botswana. Landuse, soil, geological, drainage and sewerage network and imperviousness data sets were acquired and developed in GIS database. The runoff coefficient is found to range between 0.12 and 0.24 in the studied catchments. The calibrated model was able to predict the observed outputs with reasonable accuracy for calibration datasets of two peak flood events of 2016-Jan 12 and 2017-Feb 16 and verification flood events of 2016-Feb 05 and 2017-Feb 26. For six watersheds that drain the study area considered with a seventh entire collection system catchment area, we have evaluated the model performance using different criteria. We have found that correlation coefficients range from 0.539 to 0.813 and NSE ranges from 40.9% to 89.0%, and RSR ranges from 0.330 to 0.812 for the calibration datasets. Whereas, for the verification dataset, the correlation coefficients range from 0.539 to 0.813 and NSE values range from 40.9% to 89.0%, and RSR values range from 0.330 to 0.812. Using the criteria adopted, the SWMM-simulated runoff values are in acceptable agreement with the observed hydrographs.

Application of SimaPro7 on Al-Hilla City Sewerage Network, Iraq

SimaPro is a software package designed to make a valuable contribution for analyzing the environmental impact on products during their whole life cycle. A huge amount of knowledge about the environment is built into the program and database, enabling to analyze a product with a minimum of specialized knowledge. In this study, SimaPro was used to analyze and evaluate the impacts that resulted from sewerage network in Al-Hilla city, Iraq. The results of Life Cycle Assessment (LCA) showed that sewerage network had an impact and damage on the environment by 291 points for every cubic meter of collect wastewater. The most potential environmental impacts were global warming, respiratory inorganics and non-renewable energy, contributing to the sewerage network. The study also showed that most of the effects were as a result of energy consumption in the pumping of wastewater, pipes used and diesel using for network operation.

Synchronous municipal sewerage-sludge stabilization

A study on a pilot plant accomplishing synchronous municipal sewerage sludge stabilization was conducted at a municipal sewerage treatment plant. Stabilization of sewerage and sludge is achieved in three step process: anaerobic reactor, roughing filter and a microbial earthworm ecofilter. The integrated ecofilter utilizes an artificial ecosystem to degrade and stabilize the sewerage and sludge. When the hydraulic retention time(HRT) of the anaerobic reactor is 6 h, the hydraulic load(HL) of the bio filter is 16 m 3/(m 2·d), the HL of the eco filter is 5 m 3/(m 2·d), the recycle ratio of nitrified liquor is 1 5, the removal efficiency is 83%—89% for COD Cr , 94%—96% for BOD 5, 96%—98% for SS, and 76%—95% for NH 3\|N. The whole system realizes the zero emission of sludge, and has the characteristics of saving energy consumption and operational costs.

Influence of Temperature on the Growth of Hydrilla verticillata in the Wastewater Treatment

[Objective] The research aimed to study the influence of temperature on the growth of Hydrilla verticillata in the wastewater treatment process.[Method] By using the single factor experiment design,four temperatures which were 5,15,25 and 35 ℃ were set.The growth situation of H.verticillata under the different temperatures was observed in the treatment process of domestic sewerage.[Result] H.verticillata grew luxuriantly at 35 and 25 ℃.Via the cultivation of 15 days,the plant length,branch number,root number and biomass of H.verticillata respectively increased 2.8 and 1.2 cm,7.0 and 5.9 branches,6.2 and 3.7 roots,21% and 25%,which were all significantly or extremely significant higher than that at 5 ℃.Under the cultivation condition of 15 ℃,H.verticillata grew slowly.The increment of plant length,branch number and root number were higher than that at 5 ℃,but they had no significant difference.[Conclusion] During 5-35 ℃,the higher temperature could promote the growth of H.verticillata in wastewater treatment process.

Behavior of Millstone Masonry Vaults Strengthened by Composite Materials

Sewerage systems first appeared in Paris in the middle of 19th century. Even if the majority of structures are still in working order, their general state will deteriorate inexorably, and as reconstruction is not always possible for cost and social impact reasons, rehabilitation is a solution adopted by many clients. It is necessary to resort to new rehabilitation techniques. Reinforcement by bonding composite materials has many advantages compared to other techniques. The objective of the experimental campaign presented in this paper is to study the addition of a lining by means of mortar reinforced by thin composite materials so as to restore masonry structures. To that purpose, crushing tests on masonry vaults have been carried out. The application of a lining made of mortar reinforced with composite materials has allowed increasing the breaking load and delaying the occurrence of the first cracks. This article presents the characterization of the materials. Moreover, the results of the breaking tests applied to masonry vaults are shown in this paper. A comparison with a traditional type of rehabilitation by a 6 cm-thick shotcrete lining will be performed.

Evaluation of Drinking Water Pollution and Health Effects in Baghdad, Iraq

Contamination of water reserves by biological, chemical, and radiologic agents may affect the health of millions of residents in the Iraq as well as many others throughout the world. Fatal outbreaks of cholera struck several provinces of the country, including Baghdad. The United Nations Environment Programme (UNEP) also says air pollution, resulting from burning oil and aggravated by war, is cause for concern. The study area Baghdad has been divided into two parts: Central Baghdad and Outskirts of Baghdad (included in Baghdad but near the boundaries of Baghdad). The outskirts of Baghdad comprises of 4 cities: Al-Hussaniya located in northern part of Baghdad, Abu-Gurabe located in the western side of Baghdad, Jissr Diyala located in the eastern side of Baghdad and finally Al-Mahmodiya located in the southern side of Baghdad. These cities are in very poor situation in terms of water supply. The quality of water supplied is bad as no attention is given to WTP's in these places, which is also because of the fact that given the insecure war conditions, these areas are inaccessible. The sewage is thrown directly into the river because these areas do not have sewage treatment plants. In case of central Baghdad the water supply and sewerage network are broken in some places. Due to this there is mixing of water between the two networks. For this study we taking water supply samples and collect all the samples from WTPs and water supply network (houses, shops and different places). We made the analysis to parts first bacteriologies, second chlorine and after analysis these samples in lab we will give in our study numbers of fail samples, type of diseases and how many case during year 2007 in Baghdad City. Also in this study we will give Estimated Deaths from Water-Related Diseases 2010 to 2035.

Multidisciplinary Approach for a Solution to Floods in SampathéDistrict (Thiès-Est, Senegal)

In recent years (2003), Senegal has been confronted with many urban flooding problems that have become recurrent due to the configuration of its settlement. This is due to galloping population growth, climate change and a lack of planning and rainwater drainage networks. To fix these phenomena, Senegalese government has initiated rainwater drainage programs. In the city of Thiès, particularly in Sampathé district, flooding problem is a reality that is observed during every winter period. It is within this framework that we have proposed a project for the design and dimensioning of a rainwater evacuation network in Sampathé. The network will be integrated into a Geographic Information System for efficient management of project. This study involved identifying flood zones, determining geotechnical characteristics of the soil, and exploiting rainfall data in order to propose a storm water drainage network that will be integrated into a database management system. Thus, we carried out topographical and geotechnical studies, then designed and dimensioned the drainage network, and finally set up a geographic information system. At the end of this project, we designed a sewerage network consisting of two primary pipelines, four secondary pipelines, one tertiary pipeline, ninety-two manholes and a retention basin. To manage the network, we set up a geographic information system to geolocate various elements for rapid intervention in the field in event of a problem, make requests, generate thematic maps, and perform spatial analyses for good decision-making.

Conceptual Modelling and Data Based Techniques to Understand Urban Water Use and Wastewater Production

A systems approach is used to describe the generation and variation of wastewater in an urban area. This is a multivariable system and its combined response at the outlet of this system, which is usually the entrance ofa wastewater treatment plant, depends on a number of environmental （precipitation and temperature） as well as social （size of the urban area, population changes, water consumption per capita） variables. There is a large number of available models and tools for describing the urban water system, however, the interactions between the individual components are rarely considered within the same modelling framework. In this paper a parsimonious methodology is proposed in order to understand and estimate the wastewater generation and its characteristics in an urban area using any information provided by the available data. The model incorporates both the flows of stormwater discharge and wastewater production that arrive to the wastewater treatment plant. A state dependent variable is introduced to simulate the consumptive uses in the urban area. Data availability and system＇s complexity affect the ability to achieve enhanced model performance, however, in the presented case study, preliminary results from the application of the presented model in the Greater Athens Area illustrate the potential of the conceptual modelling approach.

Sulfuric Acid Resistance of Concrete with Blast Furnace Slag Fine Aggregate

The deterioration of concrete by sulfuric acid attack in sewage environments has become a serious problem for many existing sewage structures. In this study, the properties of concrete using the blast furnace slag have been examined. It was shown that by using the blast furnace slag fine aggregate and blast furnace slag fine powder, it is possible to enhance the resistance of mortar and concrete to sulfuric acid. The resistance to sulfuric acid of mortar and concrete can be improved by using a blast-furnace slag fine aggregate in the total amount of fine aggregate. When mortar or concrete reacts to sulfuric acid, dihydrated gypsum film is formed around the particulate of the fine aggregate. This dihydrated gypsum film could retard the penetration of sulfuric acid, thus, improving the resistance to sulfuric acid. Furthermore, it has been proved that the relationship between the erosion depth by sulfuric acid attack and the product of immersion period and concentration of sulfuric acid can be expressed linearly. However, this relationship is dependent on the type of materials of concrete.

Effects of carbonation on mechanical properties of CAC-GGBFS blended strain hardening cementitious composites

Calcium aluminate cement(CAC)—based strain hardening cementitious composites(SHCC)has been developed and used for the rehabilitation of sewerage pipelines.In addition to well-known microbiologically induced corrosion,CO_(2)concentration in the sewerage environment is high,which may cause significant carbonation of pipelines.Thus,this paper aims to investigate the effects of carbonation on the mechanical performance of CAC-based SHCC.Two types of CAC-based SHCC with different strength grades and a referenced OPC-based SHCC were prepared.The accelerated carbonation test was conducted in a carbonation chamber with a 5%CO_(2)concentration.The compressive and tensile behaviour of SHCC was tested first,and microstructure analysis,e.g.,X-ray diffraction and scanning electron microscopy,was then performed.The results showed that CAC-based SHCC specimens exhibited robust strain-hardening performance as well as large deformation capacity in tension due to the fiber-bridging effect.Also,the compressive and tensile strength was significantly improved as well as achieving a higher tensile strain capacity after carbonation when compared with OPC-based SHCC.Microstructure analysis revealed that the metastable phases in carbonated CAC-based SHCC were converted into stable phases and calcium carbonate polymorphs,densifying the binder matrix.The obtained results of this paper may provide new insight into utilizing carbonation to avoid the unstable conversion of hydrates in calcium aluminate cement.