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In Indonesia’s slum areas, Inadequate sanitation is a major challenge. This study introduces an interactive web-based platform, UPSS (“Upgrading Slum Sanitation”), to aid in selecting appropriate sanitation technologies for these regions. UPSS integrates a Decision Support System (DSS) to streamline the decision-making process. Our objective was to create UPSS to facilitate the selection of suitable sanitation technologies, tailored to the specific needs of Indonesia slum areas. We employed a mixed-methods approach to develop UPSS, focusing on user-friendly interfaces and streamlined decision-making processes. The first screen will help identify the slum classification (high, middle and low slum) by using the questionnaire. The following screens will identify alternative sanitation technologies. After that we apply the UPSS in the case study area, Manado Indonesia. The application of UPSS in slum areas of Indonesia demonstrated its effectiveness in reducing planning time for sanitation improvement. The results, presented in an easily interpretable format, showed a range of sanitation options and were well-received by facilitators in these areas. UPSS proves significant in improving sanitation planning in slums. It offers a quick, efficient, and user-friendly tool for stakeholders to identify and implement the most suitable sanitation technologies, thereby addressing a critical need in urban sanitation management

Using wastewater in response to water-related challenges from climate variation has gained significance. Various sophisticated technologies have been developed to meet the demand for wastewater treatment and reuse. Graywater, an intrinsic component of wastewater, is acknowledged for its practical potential in the context of reuse. Decentralized wastewater treatment systems, exemplified by Moving Bed Biofilm Reactors (MBBRs), have emerged as efficient alternatives in urban settings. By comparing the physicochemical analyses conducted in the three treatment units and evaluating the treatment efficiency of each unit, we will first establish the validity of the MBBR system for treating and recycling graywater, achieving up to 98% elimination rates for BOD5. Subsequently, the possibility of optimizing the system will be explored by evaluating the different treatment stages of MBBR reactors. [ABSTRACT FROM AUTHOR]

The environmental impact of tire wear emissions has become increasingly apparent, and efforts to reduce their impact on the environment are on the rise. To minimise the generation of tire wear, it is essential to consider the influencing factors. However, as it cannot be entirely prevented, measures to reduce immissions are also necessary. This paper summarises possible measures derived from the literature, stakeholder workshops, and the authors' own conclusions, taking into account the different perspectives: tire, vehicle, road, sustainable mobility and emissions treatment. The presentation of the entry paths of tire wear into the environment and the hotspots of generation can be used to prioritise reduction measures. Measures should be implemented at a political level, technical solutions applied, and awareness raised among the general public. It is evident that reducing tire wear is a complex task that requires a transdisciplinary approach. [ABSTRACT FROM AUTHOR]

Microplastic (MP) has emerged as a significant environmental challenge due to increased plastic production and its widespread presence in the environment. This study aimed to assess MP concentrations throughout the treatment process at nine wastewater treatment plants (WWTPs) in Germany, from influent to effluent. A customized sampling technique was employed, followed by field and laboratory preparation and the quantification of polymers (PE, PP, PS, PMMA, and PET) using TED-GCMS. MP concentrations decreased progressively in the WWTPs, with influent concentrations ranging from 2.5 to 13.6 mg/L. Effluent concentrations in the conventional WWTPs ranged from 0.001 to 0.051 mg/L, while advanced treatment via filtration yielded concentrations below the limit of quantification at 0.005 mg/L. All tested of the WWTPs demonstrated an over 99% removal efficiency for microplastics. Despite effective retention by the WWTPs, a critical evaluation of the results is necessary. There is a need to optimize existing technologies and enhance the standardization of sampling, processing, and measurement methods, as well as intensify efforts towards creating preventive measures to reduce plastic emissions. [ABSTRACT FROM AUTHOR]

The paper is discussing microplastics in the effluent of wastewater treatment plants and other discharges from urban areas. The aim of the discussion is to expose the challenges related to sampling and detecting plastic particles in treated wastewater. The different types of microplastics and a rough estimation of the amount of plastic which could end up in the aquatic environment is given. The work is based on a literature review of microplastic particles in treated wastewater and discusses their consequences on the aquatic ecosystem.

Wastewater treatment companies are particularly confronted by the energy and supply crisis resulting from the war in the Ukraine. More specifically, production and supply problems with precipitant production have shown that today's wastewater treatment technology in Germany is not crisis-proofed and must become more resilient. The aim of this paper was to determine a required precipitant quantity for Germany with regard to chemical phosphorus elimination, as well as the expected shortfalls due to the shortage situation. Furthermore, possible solutions were identified for how the precipitant can be saved or substituted. Study surveys were conducted to gather data for a meaningful response regarding the operators (wastewater treatment plants, industry, and water suppliers), manufacturers, and the German federal states. A recommendation is given on what a path to more resilient wastewater management with a focus on phosphorus elimination could look like. Based on the data obtained, the report focused on wastewater engineering issues for wastewater treatment plants and industry. The results of the study are relevant for decision-makers, researchers, and operators in the wastewater sector in order to intervene in the market themselves if necessary, e.g., money for production or conversion to biological phosphorus elimination. [ABSTRACT FROM AUTHOR]

The management of water resources is crucial for sustainable development, necessitating innovative solutions to address the increasing demand for safe water. Alternative approaches must be adopted to effectively engage young generations in understanding the importance of water resources. This chapter reports on an experiment that aimed to promote sustainability education by linking wastewater treatment and reuse with an educational garden. In particular, an undertaking was executed to establish a decentralized wastewater treatment system wherein purified water was employed for the purpose of irrigation. The study's primary focus is on the association between urban water management, wastewater recycling, and environmental education. The study has two distinct components. The first segment discusses three examples of projects that have employed urban wastewater treatment and reuse to generate environmental education materials using various approaches. The second component features a case study of a public high school in Casablanca, where students participated in a questionnaire and participatory workshops to design an educational garden. The study's outcomes include a proposed educational garden design that will be presented to the relevant authorities and project partners. [ABSTRACT FROM AUTHOR]

Plastic in the environment poses an increasing challenge. Microplastics, which include tire wear, enter the aquatic environment via different pathways, and increasing vehicle traffic leads to increased tire wear. This paper describes an approach for how inner-city tire wear hotspots can systematically be identified by sampling road-deposited sediments (RDS) by sweeping. Within the investigations herein described, six inner-city monitoring sites were sampled. The total masses of solids as well as the amount of styrene-butadiene rubber (SBR) representing Tire and Road Wear Particles (TRWP) were determined. It was shown that the sites differ significantly from each other with regard to SBR parts. The amount of SBR in the curve was on average eight times higher than in the slope, and in the area of the traffic lights, it was on average three times higher than in the slope. The RDS mass results also differ but with a factor of 2 for the curve and of 1.5 for the traffic light. The investigations and the corresponding results in this paper are unique, and the monitoring approach can be used in the future to derive and optimize sustainable measures in order to reduce the discharge of TRWP into the environment by road runoff. [ABSTRACT FROM AUTHOR]

Due to the country's expanding population, inadequate urban water management practices, limited community knowledge of water management, and urbanization, urban water management in Ethiopia is of great importance to the administration of the country. This study draws on a qualitative and quantitative research approach to evaluate the available water supply resources and management techniques in three Ethiopian metropolitan districts, factor in the sustainability of the urban water supply services, and then recommend a workable plan for a sustainable urban water management system. Open-ended and semi-structured questionnaires were used to interview urban water utility officials to reveal important information on water demand management and current water supply services. Documented secondary data analysis and field observations are also used to identify the existing problem in order to draw future suggestions. The findings of this study indicate that some of the common issues with urban water supply systems in towns include outdated water supply infrastructures, rapid population growth and corresponding water demand, high water losses in the distribution system, poor water management practices, and a lack of appropriate institutional framework. The assessments of the three study regions demonstrate that while the percentage of water supply coverage hasn't changed significantly over the previous 10 years, both the number of customers and the overall population growth have increased by nearly 50%. In order to address this, the Ethiopian government would need to put up a lot of effort into developing water use policies and raising consumer understanding of water demand management techniques. [ABSTRACT FROM AUTHOR]

This paper describes an innovative Decentralized Technical Sustainable Drainage System (SuDS) concept, which is based on technical devices, such as sieves, sedimentation barriers, floating barriers and a magnetic module, which addresses, mainly, the fine matter. The SuDS is designed as a retrofit system so that no costly and time-consuming conversion measures are necessary. Due to the possibility of free configurability of individual modules in the three levels, road, gully and drain, a novel solution approach is presented, which is not available on the market, for a reduction in solids in general and microplastics in particular. The retention performance of selected modules and their combinations is demonstrated by means of bench tests according to the test procedure of the German Institute for Construction Engineering (DIBt) for the evaluation of decentralized treatment systems. Four different rain intensities, from light to medium up to heavy rain, are charged to the filter modules. Collected and fractionated road-deposited sediment (RDS) was selected as the test substance (10 kg). Additional tests with tyre powder, PE pellets, cigarette butts and candy wrappers helped to make clear the filter process of the particulate matter. The retention performance was determined by the mass balance between the defined dosage and at the outlet. For this purpose, the total volume flow of the effluent was passed over a stainless-steel sieve with a diameter of 600 mm and a mesh size of 20 µm. For the test substance, RDS retention rates up to 97% were measured. Very fine matter, particularly, was technically challenging to obtain; <63 µm up to 66% could be retained by the filter modules. Modules in the road space, such as porous asphalt or additional retention spaces, in the area of the curb as well as direct infiltration in the road drainage shaft are theoretically described and discussed. The outlook also addresses the potential of an intelligent network to reduce the input of pollution from urban stormwater runoff. [ABSTRACT FROM AUTHOR]

The need to support existing sewage systems is obvious due to the noticeable consequences of climate change, such as extreme rainfall, which is causing more urban flooding. It is believed that these phenomena will intensify in the long-term, and that sewage systems will be overloaded with stormwater. Consequently, cities will need more opportunities to protect themselves from flooding. Moreover, longer periods of drought will increase the temperatures in towns. The use of blue and green infrastructure is being used to adapt to climate change and to limit its effects in cities. However, it is important not to apply these solutions indiscriminately. They have obvious advantages, but are also limited in their uses. Facilities are also being developed for the design and construction of green infrastructure. This article presents the benefits of using rain gardens in urban spaces and in relation to other forms of blue–green infrastructure; it also explored the problems that may occur while using them. More important facilitations in the implementation of rain gardens into urban fabrics are discussed, particularly in the context of the existing inconveniences. A holistic approach to the issue was applied addressing technical, economic, environmental, and social aspects. [ABSTRACT FROM AUTHOR]

Agricultural reuse of dewatered sludge is a valid route for sludge valorization for small and mid-size wastewater treatment plants (WWTPs) due to the direct utilization of nutrients. A more stringent of German fertilizer ordinance requires the degradation of 20% of the synthetic additives like polymeric substance within two years, which came into force on 1 January 2017. This study assessed the use of starch-based polymers for full-scale dewatering of municipal sewage sludge. The laboratory-scale and pilot-scale trials paved the way for full-scale trials at three WWTPs in Germany. The general feasibility of applying starch-based 'green' polymers in full-scale centrifugation was demonstrated. Depending on the sludge type and the process used, the substitution potential was up to 70%. Substitution of 20-30% of the polyacrylamide (PAM)-based polymer was shown to achieve similar total solids (TS) of the dewatered sludge. Optimization of operational parameters as well as machinery set up in WWTPs is recommended in order to improve the shear stability force of sludge flocs and to achieve higher substitution potential. This study suggests that starch-based biodegradable polymers have great potential as alternatives to synthetic polymers in sludge dewatering. [ABSTRACT FROM AUTHOR]

Phosphorus (P) is a limited resource, which can neither be synthesized nor substituted in its essential functions as nutrient. Currently explored and economically feasible global reserves may be depleted within generations. China is the largest phosphate fertilizer producing and consuming country in the world. China's municipal wastewater contains up to 293,163 Mg year of phosphorus, which equals approximately 5.5% of the chemical fertilizer phosphorus consumed in China. Phosphorus in wastewater can be seen not only as a source of pollution to be reduced, but also as a limited resource to be recovered. Based upon existing phosphorus-recovery technologies and the current wastewater infrastructure in China, three options for phosphorus recovery from sewage sludge, sludge ash and the fertilizer industry were analyzed according to the specific conditions in China. [ABSTRACT FROM AUTHOR]

The removal performance and the selectivity sequence of separate metal ions (Fe2+, Cr3+, Cu2+, Zn2+ and Ni2+) in aqueous solution were studied by adsorption process on untreated and natural volcanic tuff. A series of experiments were conducted in batch-wise and fixed-bed columns to investigate the removal efficiency of natural Jordanian volcanic tuff as low cost and an effective adsorbent for heavy metal ions and to examine its economical application in water purification and treatment practices. Water and wastewater samples containing metal ions with concentrations ranging from 1 to 15 mg/L were used. The plexi glas columns were filled with natural occurring volcanic tuff particles ranging between (0.350 - 3.000) mm. Photometric methods were used for laboratory analysis of samples. The experiments were carried out under changing conditions as a function of different pH-values (2,4,6 and 7), initial solute concentrations (1, 5, 10, 15) mg/L, and different room temperatures (20, 25 and 30 C°), and varying tuff particle sizes (0.35 -3.0) mm. The breakthrough curves were derived by plotting the normalized effluent metal concentrations (C/C0) versus bed volume. Obtained results showed that natural Jordanian volcanic tuff has an adsorption capacity of 0.417 mg/g for Fe 2+ and 0.151mg/g for C 2+. Factors in the reaction medium such as pH and ionic strength influenced the adsorption process. The quantity of particular ionic species (Cu2+, Pb2+, Cr2+ ,Fe2+, Zn2+) bound in dependence on the initial concentrations, indicates that the removal efficiency from the liquid phase follows the sequence Fe2+>Cu2+>Pb2+> Cr2+>Zn2+ when keeping the pH at 4 and follows the sequence Cu2+>Zi2+>Fe2+>Cr2+>Pb2+ when keeping the pH at 6. Equilibrium modeling of the removal showed that the adsorption of the metal cations Cr2+, Pb2+, Zn2+ , Cu2+ and Fe2+ were fitted to one of the adsorption isotherms. [ABSTRACT FROM AUTHOR]

In rural areas, the quality of the water bodies will continue to be influenced by the purification performances of small and smaller wastewater treatment plants (WWTPs). In this paper, the different methods of wastewater discharge and treatment currently available for rural areas were presented. Today, both technical and natural methods achieve purification results which are equivalent to, if less stable than those of larger technical pants, provided that dimensioning, design, and operation are optimally cared for. The general question will be to decide for a centralized wastewater system or for local, on-site solution installing small treatment plants. Important criteria for this decision as the distance between the houses and also crucial dimensioning parameters like the amount of wastewater will be given within the report. Several wastewater treatment technologies will be explained and also results from the SBR-System, which are applied in Germany special in smaller communities, are discussed. The evaluation of monitoring values showed that on average the required effluent qualities could be obtained. But still one has to consider that there are technical and economic limits of the degree to which WWTPs can be cared for in rural areas. For on-site treatment the main reasons is the organization of a good operation, maintenance and surveillance. [ABSTRACT FROM AUTHOR]

In rural areas, small wastewater treatment plants (SWWTPs) are a cost-efficient solution to sewage disposal issues. In Europe, SWWTPs are defined as plants for treating domestic wastewater up 50 PE. In Germany, about 2.2 million SWWTPs are in operation or are being installed. In France about 10-12 million people are served by decentralized systems. There are many different technical solutions on the market, ranging from artificial wetlands, reed bed filters to activated sludge systems. All systems available on the European market have to meet the EU-Certification EN 12566-3, which regulates a minimum standard of operation reliability and purification limits. Furthermore, additional guidelines have to be considered, depending on national and regional specifications. There is still a lack of information about performance, operation reliability and maintainability of the different types of SWWTP under real operating conditions. These parameters are however, of particular importance to both customers and service providers. To fill this gap, during a duration time of 14 mon in this study 12 different treatment systems were simultaneously compared and evaluated under real operating conditions. The study delivers now detailed information about the performances of different plant models with regard to purification capacity, effluent values, operating expenditures, sludge treatment etc. The study was performed at the Training and Demonstration Centre for Decentralized Sewage Treatment (BDZ) in Leipzig with a special range of small wastewater treatment plant, already installed at BDZ for training purposes as well as two additional plants, which has been installed there especially for the compass study. [ABSTRACT FROM AUTHOR]

Hydrogen sulphide (H2S) emissions are one of the major problems associated with sewer networks. This gas, with its characteristic smell of rotten eggs is highly toxic and leads to the corrosion of sewer infrastructures. To protect cities and ensure the safety of sewer workers, sewers are commonly monitored using H2S gas sensors. In this work, three commercial H2S gas sensors for air quality monitoring were compared at two different sites in Berlin, Germany. Two of the sensors provide online access to data, while the other one is a data logger. Moreover, based on statistical measures (RMSE, MAE, MB, and a graphical analysis), we evaluated whether a rotation/exchange between data logger (reference) and online sensors is possible without significant differences in the gas measurements. Experimental evaluation revealed that measurement differences are dependent on the H2S concentration range. The deviation between sensors increases as the H2S concentration rises. Therefore, the interchange between reference and online sensors depends on the application site and the H2S levels. At lower ranges (0–10 ppm) there were no observed problems. Finally, to support practitioners on-site, a management procedure in the form of a decision-making tool is proposed for assessing whether gas sensors should be exchanged/rotated. [ABSTRACT FROM AUTHOR]

Sulphide build-up in pressure sewers has been identified as the main cause for the occurrence of odour and corrosion in sewer systems. Despite the efforts to optimize commonly used control technologies such as nitrate and iron salts to reduce sulphide emission, continuous addition of these chemicals is still required. A biocidal agent such as free nitrous acid can be added intermittently, less frequently, and in smaller quantities whilst achieving total sulphide control. So far, laboratory and field studies in Australia and the USA have successfully proven and applied the use of this control technology, exhibiting its strong biocidal effects during intermittent addition. In this study, nine trials were made to assess the application of the free nitrous acid (FNA) as an alternative sulphide control technology in Germany. The sewer pilot plant of the Berlin Water Utility Company was used to perform the trials at a technical scale using a supply of raw sewage. FNA exposure times ranging from 5 to 24 h in varying concentrations were investigated. The effectiveness of the FNA treatment was monitored using the online hydrogen sulphide (H2S) gas and dissolved-sulphide sensors installed in the sewer pilot plant. Effective sulphide control was only possible during dosing periods, with rapid resumption of sulphide production for the trials with exposure times of <12 h and concentrations ranging from 0.08 to 0.56 mg HNO2-N L−1 suggesting a slight inhibitory effect. A more pronounced biocidal effect was observed for the trials exposed to FNA treatment for 24 h at concentrations >0.29 mg HNO2-N L−1. Overall, the trials of this study demonstrated that the biofilms were FNA resistant and that the concentrations and exposure times used were inadequate to develop an effective intermittent dosing strategy. [ABSTRACT FROM AUTHOR]

A part of the sustainable drainage systems (SuDS) are used to treat stormwater and must be tested for their hydraulic performance and the removal efficiency to assess serviceability and retention of the pollutants efficacy for in situ use. Current test procedures provide a good basis for laboratory testing SuDS on the test stand. However, the evaluation is not sufficiently representative to compare different SuDS with each other or for in situ use. The individual steps and specifications of an applied test procedure in Germany were considered and evaluation and optimizations for the test substance and sampling methodology of SuDS on the test stand were proposed. A comparison of the particle size distribution of the test substance Millisil W4 currently in use and total suspended solids of real road runoff was made, which showed that the presented test substance of real road-deposited sediments (RDS) provides a better reference for the test conditions and they could be the basis for more representative test methods. A particle size distribution was proposed for this new test substance. Furthermore, two methods of sampling were compared, which showed that a full flow sampling is preferable to a discrete sample. At the same time, it was shown that a separation limit of 20 µm is sufficient for the determination of TSS63. [ABSTRACT FROM AUTHOR]

• Three ensemble learners were evaluated in predicting concrete corrosion in sewers. • Five soft computing base learners were employed. • Network-based and tree-based machine learning methods were assessed. • The random forests (RF) model performed better than the other models. • Ensemble learners acted better in alleviating the problem of over/under-simulating. This research aims to evaluate ensemble learning (bagging, boosting, and modified bagging) potential in predicting microbially induced concrete corrosion in sewer systems from the data mining (DM) perspective. Particular focus is laid on ensemble techniques for network-based DM methods, including multi-layer perceptron neural network (MLPNN) and radial basis function neural network (RBFNN) as well as tree-based DM methods, such as chi-square automatic interaction detector (CHAID), classification and regression tree (CART), and random forests (RF). Hence, an interdisciplinary approach is presented by combining findings from material sciences and hydrochemistry as well as data mining analyses to predict concrete corrosion. The effective factors on concrete corrosion such as time, gas temperature, gas-phase H 2 S concentration, relative humidity, pH , and exposure phase are considered as the models' inputs. All 433 datasets are randomly selected to construct an individual model and twenty component models of boosting, bagging, and modified bagging based on training, validating, and testing for each DM base learners. Considering some model performance indices, (e.g., Root mean square error, RMSE ; mean absolute percentage error, MAPE ; correlation coefficient, r) the best ensemble predictive models are selected. The results obtained indicate that the prediction ability of the random forests DM model is superior to the other ensemble learners, followed by the ensemble Bag-CHAID method. On average, the ensemble tree-based models acted better than the ensemble network-based models; nevertheless, it was also found that taking the advantages of ensemble learning would enhance the general performance of individual DM models by more than 10%. [ABSTRACT FROM AUTHOR]

Hydrogen sulphide (H 2 S) emissions in sewer systems lead to several problems such as corrosion, odour nuisances, and health damage to sewer workers. Although the gas is formed in the liquid phase, its effects are noticeable when released into the sewer atmosphere. Until recently, the lack of analytical procedures for continuous monitoring of H 2 S in the liquid phase, as well as its toxicity, have challenged the quantification of the mass transfer coefficient under real conditions. Because of this, most studies have mainly focused on batch experiments with artificial wastewater and/or oxygen. The aim of this study was to experimentally determine the overall mass transfer coefficient for H 2 S during intermittent pumping events common in actual sewer systems, using the two-film theory approach and employing online sensors for liquid and gas phase measurements. The mass transfer coefficient was quantified by carrying out 21 experiments with actual wastewater in a 25 m long gravity pipe of a sewer pilot plant located in Berlin (Germany). Results show that the corrected mass transfer coefficient (K L a 20 ) during a pumping event ranged between 0.1 and 8 h -1 with a median value of 4.2 h -1 , within the range of the results obtained by the most common empirical models.

UV/Vis spectrometers are powerful tools for online monitoring of wastewater constituents and processes. However, most studies only focus on typical parameters such as chemical oxygen demand (COD) and total suspended solids. This work presents a multi-parameter approach for calibration of a UV/Vis spectrometer for online monitoring of sewer systems. Parameters studied include soluble and total COD, nitrate, ammonium, sulphate and orthophosphate, as well as total dissolved sulphide, bisulphide and hydrogen sulphide, because they are one of the main causes for odour and corrosion in sewer systems. Two calibration methods are compared: multiple linear regression included in the manufacturer's software, and partial least square (PLS) computed using the pls package of the R library. Performance of the methods is evaluated for calibration and validation data sets employing four different criteria: relative root mean square error (RMSE rel ), RMSE-observations standard deviation ratio, Nash-Sutcliffe efficiency and percentage bias. A method-parameter dependency was revealed during the calibration phase but, when predicting new data, the PLS method showed higher robustness for almost all parameters. Both methods were able to predict concentration trends associated with sewer processes, some of which are strongly correlated to the sulphide species.