Several local groundwater studies within the EU project AquaTerra in the Basins of the Meuse, Elbe point at significant influences of groundwater on surface water, while the Brévilles Catchment shows a distinct problematic of pesticide loading to groundwater. Further modeling studies are currently being developed. In the Danube Basin no specific groundwater studies were carried out in the framework of AquaTerra. However on larger scales geochemical proxies such as strontium isotope ratios can give an insight into groundwater contributions to the river that reflects an integral signal of the environmental status of the Basin. Future local groundwater studies should be further correlated to the environmental status of rivers nearby.
This paper explains how the results of the source water characterisation for the Western Corridor Recycled Water Project in South East Queensland was used to augment the qualitative water quality risk assessment process and design of the monitoring programs. Results were evaluated against health standards published in 2008 by Queensland Health and also against level of reporting. This determined the relative risk of exceeding the health standard for parameters detected in the source. The relative risk was used to inform the qualitative risk assessment as well as the frequency of monitoring in both the source and purified water. Categorising hazards using their ionic charge and hydrophobicity enabled the selection of indicators for both source and purified water compliance monitoring programs. Yes Yes
The National Biosolids Research Program (NBRP) was established by the CSIRO Centre for Environmental Contaminants Research in 2002 in order to coordinate research relating to the benefits and risks of using biosolids for Australian agriculture. Prior to the establishment of the NBRP, research on biosolid use in agriculture had been concentrated in one state (New South Wales), with pockets of uncoordinated activity in other states. The NBRP is a coalition of seven research agencies around Australia, with support from several metropolitan and regional water authorities, and from several state environmental and natural resource management agencies. In terms of potential environmental risks, the NBRP initially concentrated on metals and focussed field experimentation on cadmium, copper and zinc. The research has subsequently moved onto examining potential risks from pathogens, pharmaceuticals, endocrine disrupting compounds and personal care products. As well as potential risks, the benefits of nutrients and organic matter in biosolids on crop growth are also being assessed, with various cropping systems around Australia being evaluated.
Sewage sludge is a serious problem due to the high treatment costs and the risks to environment and human health. Looking to the future the question arises of which sludge research and development issues are most important. Based on a brief evaluation of current sludge treatment systems and research results it can be concluded that land application of sewage sludge remains one of the most attractive options. However, more research into the health risks is necessary to make this method worldwide more acceptable. Recovery of energy from sludge is becoming more and more attractive. High thermal processes are interesting if sludge does not satisfy the guidelines for land application. Integration of these high thermal processes with existing industrial activities or other thermal waste treatment processes can be very attractive. Research into dewatering and drying can make the energy recovery more efficient. Processes for recovery of valuable products from sludge such as aquatic worms and P-compounds are potentially very attractive but their feasibility strongly depends on the marketing and market value of these products. It is expected that supercritical sludge treatment and direct production of electricity require still a long research and development path.
4th IWA Specialist Conference on the Efficient Use and Management of Urban Water Supply, Jeju Island, Korea, 21 – 23 May 2007 There is a need in South Africa for institutional innovations aimed at increasing the coverage and reliability of water services, and sustaining those services. The paper describes an alternative service delivery institutional concept, viz the franchising of the operation and maintenance of water services, and outlines the need to formulate a franchise model that could be developed and made available to emerging entrepreneurs as the basis of a viable business. The franchise would be in respect of components of the water services value chain that are suitable for small business in that they can be readily systematised
The fouling of a reverse osmosis membrane after one year of service in a brackish water treatment plant was investigated. It has been found that the extent of fouling was uneven across the membrane surface with regions underneath or near the strands of the feed spacer being more severely affected. This is attributed to the local variations in the hydrodynamic conditions, partly due to the effect of the feed spacer. Microscopic examination of the cross-sections of the fouled membrane revealed that the fouling developed through different stages as suggested by the multi-layered structure of the surface deposits. In particular, the initial fouling stage involved the formation of a surface layer less than about 7 μm thick which consisted of an amorphous matrix comprising organic–Al–P complexes with embedded particulate matter, mostly aluminium silicates. Subsequent fouling involved the deposition of further amorphous material on top of the existing fouling layer. This secondary amorphous material did not seem to contain any particulate matter nor any inorganic elements, and is suggested to include extracellular polymeric substances. As the fouling proceeded further, aluminium silicate crystals started to grow exclusively on top of the secondary amorphous material in the absence of other foulants.
This paper presents the results of research into the social impacts of stormwater management techniques applied within urban environments. The main aim of the study was to compare public and professional attitudes of stormwater management practices such as Sustainable Urban Drainage Systems (SUDS) and river management techniques. Any new and innovative technology used in residential areas, besides being economically and environmentally acceptable, must also be accepted by the residents. There has been considerable interest in the assessment of the public perception of SUDS in the UK by consultants, developers, the Environment Agency of England and Wales as well as by the Scottish Environment Protection Agency (SEPA). This research was undertaken to inform such interest and also to obtain a more holistic view of the perception by professionals of SUDS. A comparative study of the perceptions of river management in three densely populated European cities facing similar storm water management problems was carried out. The selected cities were Glasgow in Scotland – U. K., an area in west London, England - U.K., and part of Athens - Greece. All sites were located within flood-prone suburban areas, and different river management techniques have been proposed or adopted.
It was confirmed experimentally that Roughing Filter (RF) is effective as a pre-treatment system for Slow Sand Filter (SSF) with coagulant dosing and mixing with raw water. This RF system can pre-treat high turbidity raw water (1000 NTU) to generate low turbidity (10 NTU) pre-treated water for SSF treatment. In the experiment, the types of filter media, height of the filter media, filtration rate and coagulant dosing were varied and the characteristics of each item were evaluated and the design guidelines were formulated. Water Treatment Plants (WTPs) consisting of pre-treatment with RF followed by SSF to treat river water were designed and constructed in Myanmar based on the design guidelines, and the operational performance was confirmed as effective to generate treated water with a turbidity under 5 NTU which is in compliance with the WHO guideline despite the rather short working period of about one year. Sand scraping of SSF at a frequency of about once in every 1 to 2 months was implemented to maintain the design filtration rate.
Eutrophication is a serious problem in Lake Victoria as a result of enrichment by nutrients transported by the rivers draining into it. River Nzoia is one of the main rivers draining into the lake. The main aim of this study was to simulate the level of nitrates using MIKE 11 and to establish relationship between nitrogen and phosphorus. The model was calibrated using water quality data for 2009 and validated with March 2013 data and then it was used to simulate nitrate concentration for the wet month of April 2013. The model performance was good with R2 values of between 0.87 and 0.98 and EF values of between 0.73 and 0.96. From the simulations, the effluent discharge from municipal and industrial wastewater ponds elevated the concentration of the nitrates in the river. Analysis of the concentrations of nitrates for wet and dry periods showed significant variations indicating significant contributions from the catchment through run-off. The relationship between total nitrogen and total phosphorus was analysed and found to have a strong positive correlation (r = 0.714, p < 0.05) indicating that both originate from similar sources or are influenced by the same factors such as agriculture.
In order to understand the isotopic characteristics of coal mine water in diverse aquifers, ten groundwater samples were collected from three aquifers – Quaternary (QA), Coal-bearing (CA), and Limestone (LA) – in Xutuan coal mine, Anhui Province, China. The geochemical characteristics of major ions and isotopes were determined, and the results showed that all of the groundwater samples are HCO3-Na·K or Cl-Na·K types. The concentrations of Na+ + K+ decreased in the order CA > QA > LA, whereas the content of Ca2+ and Mg2+ increased from CA to LA. Groundwater in LA is meteoric in origin, while that in QA is clearly influenced by surface water. The δ 13Cdic and δ 18Odic in groundwater samples from LA, QA and CA are influenced by the surrounding strata, CO2 and microorganism activity, respectively. The strontium concentration decreases in the sequence LA > CA > QA, but water samples from CA give the highest value of 87Sr/86Sr. Strontium is released by dissolution from the surrounding rock, and the 87Sr/86Sr ratio could be used to identify the groundwater source.
Dye-containing wastewater has been known as a serious environmental treat. There are many treatment methods, but they are not practical in many developing countries. In this study, batch adsorption of acid yellow 17 dye from aqueous solution has been carried out on a laboratory scale using activated water hyacinth root powder. The dye removal efficiency was measured using a UV-Vis spectrometer. Adsorption experiments were carried out in a batch process at different operating parameters including initial dye concentration, adsorbent dose, contact time, and solution pH. From the experimental data, the maximum dye removal efficiency achieved was 92.26% at pH 2, initial dye concentration 50 mg/L, contact time 120 min, and adsorbent dose 20 g/L. Experimental studies indicated pseudo-second-order kinetic (R2 = 1) and Langmuir isotherm (R2 = 0.953) models could better describe acid yellow 17 dye adsorption on the activated water hyacinth. Adsorption experiments revealed that activated water hyacinth prepared from locally available infesting water bodies had a high potential for removing acid yellow 17 dye from aqueous solution. HIGHLIGHTS
Activated carbon was prepared from water hyacinth root using phosphoric acid.;
The removal efficiency of acid yellow 17 dye was evaluated using activated carbon at different operation conditions.;
Isotherm and kinetic studies of the removal of acid yellow 17 dye onto activated carbon from water was investigated.;
With the continuous increase in environmental requirements and regulations for wastewater treatment a lot of wastewater treatment plants in Austria had to be extended. Extension of the plant requires in general an additional area, which is not always available. This study shows the extension of the WWTP Hard Hofsteig and doubling its capacity by using the Hybrid concept, which is a special two stage activated sludge process for extensive nutrient removal. The plant was extended from 170,000 PE to 270,000 PE without changing the footprint of the plant and the extension costs could be kept very low. Operational data shows that by operating the plant in the two stage Hybrid mode the energy balance of the plant can be improved.
In this study, the adsorption abilities of Russula brevipes (RB), Agaricus augustus (AA), and Fomes fomentarius (FF) were evaluated in Basic Red 18 (BR18) and Remazol Brilliant Blue R (RBBR) biosorption from textile effluent. The adsorbents were characterized via Scanning Electron Microscopy (SEM), Energy Dispersive Spectrometer (SEM-EDS), and Fourier transform infrared spectroscopy (FT/IR). Fomes fomentarius presented a low sorption capacity contrary to the two other fungi (RB and AA). RB and AA were selected as potential adsorbents for BR18 and RBBR, respectively. The maximum BR18 removal efficiencies for 10, 25, and 50 mg/L were obtained after 60 min to be 90, 88, and 86%, respectively. The RBBR adsorption efficiencies were 96.4, 96, and 90% for dye concentrations of 10, 25, and 50 mg/L. The adsorption of BR18 onto the RB biomass followed the Freundlich isotherm, while Langmuir is the best isotherm for RBBR sorption's elucidation onto AA fungus biomass. The removal of BR18 by BR biomass was found to follow the pseudo-second order. In contrast, the adsorption of RBBR onto the AA biomass followed Lagergren's pseudo-first order. For both adsorbents, the adsorption was exothermic, feasible, and spontaneous in nature. Finally, the dyes' biosorption process was perfectly achieved onto fungi biomass via physisorption. HIGHLIGHTS
Three fungi, Russula brevipes (RB), Agaricus augustus (AA), and Fomes fomentarius (FF) were used for dye adsorption.;
Basic Red BR18 and Remazol Brilliant Blue RBBR dyes were tested for adsorption.;
Freundlich describe perfectly the sorption process of BR18 dye onto RB fungus.;
Langmuir is the best isotherm for RBBR sorption's elucidation onto AA fungus biomass.;
The Tuojiang River has multiple water sources and serious pollution problems, but its hydrological mechanism in the upper reaches is still unclear. To better understand the hydrological characteristics of the Tuojiang River, the isotopic compositions of its precipitation, river water and groundwater in the upper reaches have been investigated from May 2018 to April 2019. The results indicated that the isotope values of precipitation, river water and groundwater fluctuate significantly throughout the year with depleted value in the wet season and enriched value in the dry season. Spatially, the isotope values of river water increase gradually from upstream to downstream. River water is the main source of recharge to groundwater and precipitation is the minor one. The isotope-based hydrograph separation shows that the Mianyuan River and Pihe River contribute more greatly to Tuojiang River than the Shiting River and Yazi River. The mean residence time of river water from the Tuojiang River varies from 0.95 to 1.49 years, which indicates that rivers in the upper reaches of the Tuojiang River respond to precipitation quickly. This study proved the usefulness of stable isotopes to identify the different water cycle components and reflect the pollution problem in multiple water source confluence areas.
Analysis of the spatio-temporal characteristics of isotope values in the Tuojiang river basin. Exploration of the seasonal variation of recharge source to groundwater in the Tuojiang River. Analysis of the temporal variation in the relative contribution of tributaries over total river flow. Estimation of the mean residence time of the Tuojiang River and its tributaries.
Ceramic membrane technology is used in water treatment due to the robustness of ceramic membranes, but ceramic membrane systems are costly as each membrane module is housed in individual casing. PWNT has developed a ceramic membrane system called the CeraMac which greatly reduced the capital cost of installing the system by housing up to 200 modules in a single stainless steel vessel. PWNT and PUB have jointly started a 18-month operation at Choa Chu Kang Waterworks (CCKWW). In this paper, the results of the optimization runs using settled water as feed has shown that membrane operation at flux of 200 lmh can be sustained with stable transmembrane pressure (TMP) and permeability, and the proposal to apply 0.5 mg/L residual ozone to the feed to investigate the effect of ozonated feed on membrane operational performance and fouling will be discussed.
Adsorption offers an efficient, cost-effective, and eco-friendly method for the treatment of dye-laden wastewater. This work presents reactive red 198 (RR198) removal by adsorption using bentonite clay (BC) blended with sugar cane bagasse ash (SCBA). The adsorbent's surface morphologies, crystalline phase structures, functional groups, and specific surface before and after adsorption were examined using SEM, XRD, FTIR, and BET respectively. Central composite design (CCD) under response surface methodology (RSM) was applied to optimize independent and dependent variable values. The optimal parameters for RR198 removal using the blended adsorbent were 107 minutes contact time, 0.934 g/L adsorbent dose, and 15 mg/L initial dye concentration, and 85.2% RR198 removal efficiency was achieved. The sorption isotherms and kinetics were evaluated using various existing models. The Freundlich isotherm model (R2 = 0.95) and the pseudo-second-order equation best described the adsorption parameters and the RR198 adsorption kinetic mechanism, respectively. Desorption and reusability experiments in batch study confirmed that BC blended with SCBA can be used multiple times for dye removal from wastewater. HIGHLIGHTS
Bentonite blended with SCBA as adsorbent removed RR198 from synthetic solution successfully.;
The highest RR 198 removal efficiency from water was at pH 2.;
CCD under RSM was applied to determine optimal parameters of independent and dependent variables.;
An overview of the REclaimed Water Management Scheme (REMS), Stages 1A & 1B undertaken by Shoalhaven Water, the water utility of Shoalhaven City Council, NSW, Australia, after its first twenty years of operation. REMS is one of the largest recycled effluent projects undertaken by a local government in Australia. REMS utilises tertiary treated re-claimed sewage water from the urban centres and utilises it, in lieu of potable water, for agricultural and sports field irrigation, while diverting discharge away from sensitive waterways. The REMS project was initiated to address three primary issues: Public outcry over sewage discharge into sensitive Bay/River/Ocean environments including Jervis Bay and the Shoalhaven River. To assist the Dairy industry though providing resistance to drought. To upgrade the sewerage system to enable development and address the demands of a greatly increased population. This paper places the scheme in the context of an integrated Water Utility and Local Government body, engaging stakeholders in extensive consultation, and embarking on a large project designed to have significant Environmental and Economic outcomes, culminating in an integrated multi-plant capture, treatment and distribution system. The project is focussed upon agricultural use of recycled water that has wide support public support, and benefits to both the Dairy farmers and Oyster farmers of the region. The paper examines REMS' success, its future expanded capabilities, and its application as a scalable model elsewhere.
River flooding is a key topic for water managers because of social and economic losses it can cause. The complex topography and dynamics of mountain rivers has limited the analysis of their behavior during flood events (e.g., sediment transport, flooding). This study aims to test the performance of three hydraulic 1D models (HEC-RAS, MIKE 11, and Flood Modeller) to estimate inundation water levels for a mountain river. The evaluation of these models was performed considering steady state conditions through 10 scenarios, i.e. five discharge return periods, and two types of cross sections data: (a) type I, a detailed field survey complemented with information extracted from DEM, derived from LiDAR; and (b) type II, cross sections exclusively derived from the DEM. The research was conducted for a reach of 5 km of the Santa Bárbara River, with an average slope of 0.25%. HEC-RAS model results for cross sections type I, were previously validated and therefore used as reference for comparison between other models and scenarios. The goodness-of-fit between models was measured based on the Nash-Sutcliffe model efficiency coefficient (EF). The main goal of the current study was to determine the variability of inundation levels results compared with a validated model as reference, using the same input data for the three modelling packages. Our analysis shows that, when using cross sections type I, the evaluated modeling packages yield similar results (EF were between 0.94 and 0.99). On the other hand, the goodness of fit decreased when using type II data, with an average EF of 0.98 (HEC-RAS), 0.88 (Flood Modeller) and 0.85 (MIKE 11) when compared to the reference model. The authors conclude that it is highly recommend for practitioners to use geometric data type I instead of type II in order to obtain similar performance in the tested models. Only HEC-RAS type II has the same performance as type I models (average EF of 0.98).
Tangki NAHRIM, a desktop application developed in 2008, is widely used for the calculation of optimal tank size for rainwater harvesting in Malaysia. Here we present an overview of the updated version, Tangki NAHRIM 2.0 (TN2) which was developed in R computing environment. In TN2, rainwater harvesting system is simulated using daily water balance model with rainfall input from a built-in database by adopting the yield-after-spillage (YAS) convention. Proposed tank sizes are evaluated based on water-saving and storage efficiencies. These results are then visualised in charts showing the relationships between tank sizes and both efficiency measures to help users select the optimal tank size based on their criteria of choice. A simulation was conducted based on a typical Malaysian household for domestic non-potable use as a case study. A web-based GUI for TN2 was developed in R Shiny framework for the public. The GUI has the advantage of being accessible online from any device, and will be able to facilitate the adoption of rainwater harvesting system by the public at large.
Membrane technology has emerged as a dominant solution to seawater desalination due to its superior advantages such as stable output water quality, lower energy consumption, ease of operation and smaller footprint. However, the design of spiral wound reverse osmosis (RO) membranes used in desalination does not allow for backwash or air scouring, thus rendering the RO membrane highly susceptible to fouling. Pretreatment for the RO system is therefore essential to ensure a long service life of the RO membranes. For waters containing suspended solids of up to 75 mg/L (such as that in the SingSpring Desalination Plant at Tuas, Singapore), conventional pretreatment methods (such as dissolved air floatation and filtration (DAFF), chemical dosing and cartridge filtration) require regular operator intervention to produce a permeate of reasonably quality. Ultrafiltration (UF) as a pretreatment for seawater desalination can offer better treated water, lower operating costs, a smaller footprint, and flexibility in dealing with poor or varying feed water quality. By improving the pretreatment permeate water quality, reducing operating costs and the footprint, capital expenses can be lowered. Greater stability is also achieved during times of poor or variable feed water conditions (such as periods of algalbloom). A pilot study was conducted at SingSpring to track the performance of Hyflux’s Kristal ® 2000 hollow fiber UF membranes as pretreatment for the seawater reverse osmosis (SWRO) system. The results of the pilot study will enable the design of future large-scale UF-SWRO membrane projects for seawater desalination.
For the first time in its modern history, water restriction measures were implemented during the summer 2006 in Paris. This article describes the weather conditions and the decision making of such an unprecedented event. Furthermore, the new approach to solidarity with the areas where water is extracted and derived to supply the urbanized region of Paris.
Assessment of water quality is a major step in the water industry to ensure the suitability of water for human use. In this study, statistically evaluate the quality of raw and treated drinking water of the Al-Mussaib drinking water treatment plant, Babylon city, Iraq, from January to December 2020. Additionally, the water quality of treated water was assessed according to
World Health Organization (WHO) and Iraqi standards for drinking water. The results showed the plant has a good efficiency in removing the studied parameters, such as alkalinity, calcium and hardness. It is noteworthy to mention that although the measured concentrations/levels met the WHO and Iraqi standards, they were higher than the favourable limits. For example, the measured sulphate concentration in the produced water was 248 mg/L, which is higher than the favourable concentration (200 mg/L) (WHO). The statistical analysis indicated significant differences between the quality of raw and treated water (p-value 0.05) in terms of alkalinity, pH, calcium and sulphates concentrations. The results of this work could be useful for water authorities and decision-makers in Iraq and national and international environmental agencies. HIGHLIGHTS
Water quality of Al-Mussaib drinking water treatment plant, Iraq was studied.;
Water quality was acceptable according to WHO and Iraqi standards.;
Significant differences between the influent and effluent turbidity, hardness, magnesium and dissolved solids concentrations.;
No significant differences between influent and effluent alkalinity, pH, calcium and sulphate concentrations.;
The last decade has brought many changes to Colorado's water supply outlook. Despite the recent economic recession, the state has experienced significant population growth, and Colorado's population is expected to nearly double within the next 40 years. Other pressures on Colorado's water supply include severe drought, a desire to meet multiple needs (i.e., municipal, environmental, recreational) with existing resources, and impacts to agriculture due to water shortages, urbanization, and transfers to new users. To address these challenges, the Colorado Water Conservation Board (CWCB) has undertaken a visioning process to explore solutions to these future water supply challenges. As part of this process, CWCB has led the state in identifying demand and supply strategies to meet the state's future water needs while considering agriculture and the environment. These strategies have been combined into varying portfolios that include methods such as conservation, local water projects, new Colorado River development, and agricultural transfers. This paper details the development and evaluation of these portfolios and describes stakeholder's efforts to balance meeting Colorado's water needs in the future.
The City of Baltimore, Maryland is one of many US cities faced with challenges related to increasing potable water demands, diminishing fresh water supplies, and aging infrastructure. To address these challenges, the City recently undertook a $7M study to evaluate water supply and treatment alternatives and develop the conceptual design for a new 120 million gallon per day (MGD) water treatment plant. As part of this study, an innovative raw water management tool was constructed to help model source water availability and predicted water quality based on integration of a new and more challenging surface water supply. A rigorous decision-making approach was then used to screen and select appropriate treatment processes. Short-listed treatment strategies were demonstrated through a year-long pilot study, and process design criteria were collected in order to assess capital and operational costs for the full-scale plant. Ultimately the City chose a treatment scheme that includes low-pressure membrane filtration and post-filter GAC adsorption, allowing for consistent finished water quality irrespective of which raw water supply is being used. The conceptual design includes several progressive concepts, which will: 1) alleviate treatment limitations at the City's existing plants by providing additional pre-clarification facilities at the new plant; and 2) take advantage of site conditions to design and operate the submerged membrane system by gravity-induced siphon, saving the City significant capital and operations and maintenance (O&M) costs. Once completed, the new Fullerton Water Filtration Plant (WFP) will be the largest low-pressure membrane plant in North America, and the largest gravity-siphon design in the world.
Stockholm is currently one of Europe’s fastest growing cities, with its population increasing by approximately 1.5% per year, corresponding to 15,000 to 20,000 people. Sweden’s commitment to the Baltic Sea Action Plan and the EU Water Directive will lead to more stringent effluent requirements (6 mg-Tot-N/l, 0.2 mg-Tot-P/l and 6 mg-BOD7/l), and wastewater treatment in Stockholm will require major investment to handle these challenges. As Stockholm Vatten’s two wastewater treatment plants (WWTPs) – Bromma, 320,000 people, and Henriksdal, 780,000 people – are both located in or near residential areas in the city, plant development must be coordinated with its needs on economic, political, sustainable and long-term bases. Both WWTPs being facilities located underground also pose a challenge for any extension works.
This paper presents one case of wastewater management approach in rural area. The design and the implementation of the solution have been developed in close consultation with the stakeholders and national authorities. The objectives are (i) to solve the problems of the uncontrolled wastewater discharged into nature without treatment, and (ii) to set up a robust solution to be recommended for application in rural school in Tunisia, devoid of sanitation system and characterized by limited financial resources for water supply and sanitation services. Several equipments to save water (push-button taps, waterless urinals, rainwater harvesting) is set up. The sanitation system consists of septic tank followed by horizontal subsurface flow constructed wetland. The treated wastewaters are used in the irrigation of the garden. The evaluation of the performances of the system after 3 years is presented.
Advanced Oxidation Processes (AOP) are known as an effective treatment barrier for micropollutants. Well known AOP combinations are UV/H 2O 2 and O 3/H 2O 2. This paper will present a more detailed view on how to use the different options combining UV; ozone and H 2O 2. The focus of this investigation is on treatment effects (reduction of specific contaminats), water matrix, energy consumption and cost calculation (CAPEX, OPEX). The presented data are extracted from extended pilot trials carried out at DUNEA in 2009 and 2010. Dunea (The Netherlands,The Hague) produces drinking water from the Meuse River, which contains a variety of organic micropollutants as a result from upstream activity. Dunea is performing research to extend the current multiple barrier treatment (e.g. pre-treatment, artificial recharge and recovery (ARR), posttreatment) with an advanced oxidation processes (AOP), situated at the pre-treatment location in Bergambacht, before ARR. The degradation of organic micropollutants as a result of advanced oxidation using different combinations of hydrogen peroxide, ozone, low pressure (LP) UV lamps has been assessed by means of pilot-scale (5 m 3/h) experiments. The influent was pre-treated river water, with an yearly average UVtransmission of 80% and a DOC concentration of 4 mg/L.The peroxide doses were varied as 0, 5 and 10 ppm, the ozone doses were varied as 1, 2 and 3 g ozone/m 3. The UV doses were varied between 300 and 650 mJ/cm 2. The installed power for the LP reactor was 0.26 kWh/m 3. Atrazine, bromacil, ibuprofen and NDMA were spiked (10-20 μg/L) and used as model compounds. Bromacil was completely (>99%) removed by ozone/peroxide. Atrazine and ibuprofen were good (58% and 85% respectively) removed by O 3/H 2O 2 and NDMA was not (9%) removed by this technique, whereas NDMA showed good (82%) removal by UV/H 2O 2. Atrazine, bromacil and ibuprofen were degraded by UV/H 2O 2 at 53, 46 and 59%, respectively. In addition also combined AOP was tested; spiked water was treated by O 3/H 2O 2 first and let over the LP-UV reactor directly afterwards. All four compounds showed highest degradation during combined AOP treatment. With this combined AOP, lower ozone dose and lower UV dose result in comparable degradation compared to single AOP treatment. For all these techniques a detailed capital expenditure operational expenditure (CAPEX/OPEX) evaluation was carried out based on a daily water flow of 240,000 m 3. This evaluation resulted in the finding, that the combined AOP is the most economical solution with the best treatment result. Other advantages of the combined AOP are limited by-product formation, especially bromate, and a future barrier against OMPs encompassing a broad spectrum of properties.
Ever-increasing coffee consumption results in the generation of a significant amount of solid residue in the form of spent coffee grounds (SCG) and their subsequent disposal causes environmental pollution. Valorization of SCG through pyrolysis could be one of the solutions to this challenge. Pristine biochar of SCG shows less efficiency to remove dyes from aqueous solutions. Herein, iron(III) salt was used as a catalyst during the carbonization of SCG and has a good graphitization efficiency and thus enhanced the formation of aromatic structures, which provide adsorption sites for the dye. The physical characteristics of the prepared biochar were analyzed by FTIR, XRD, and BET. A predictive model for the removal of the dye was investigated with the Design Expert 11.0 software through the central composite design (CCD) - response surface methodology (RSM) by conducting a batch adsorption study, and the suggested optimum values of the CCD were 10 ppm initial dye concentration, 1 g per 100 ml adsorbent dose, and contact time of 101 min with optimum predicted dye removal of 99%. The Langmuir model was the best fitted isotherm model with an adsorption capacity of 2.07 mg/g, and the adsorption kinetic equilibrium data was better described by the pseudo-second-order model and from the thermodynamic study, it has been suggested that the adsorption process was spontaneous, favorable, endothermic, and a physicochemisorption in nature. The possible adsorption mechanisms governing the adsorption process of the dye with biochar are π – π electron donor-acceptor interactions and hydrogen bonding.
Groundwater resources along the coast of Cameroon (Kribi–Campo Sub-Basin) are under siege from point and non-point pollution sources, climate change, urbanization and infrastructure development. This situation is made worse by the absence of a water management and development strategy. Managing and monitoring the area's water resources requires an understanding of the groundwater systems, and thus a thorough understanding of the geology. In this study, a 3D geological model was built from electro-seismic data and the structure of the area's aquifer system developed. The aquifer system structure was transferred into Visual MODFLOW Flex and then used to develop a typical hydrogeological model, which will help the management and monitoring of the area's groundwater resources. As more geological data become available, the current model can be updated easily by editing and recomputing. This work is expected to have a positive impact quite quickly on the provision of potable water and on public health.
Good practice and standards set strict requirements for optimization and continuous improvement of physical asset management. The new international standard for asset management provides a framework for asset intensive industries to develop and implement sound asset management systems. Unlike the largest and most global industries, there are very few, if any, providers of services in the water sector that have developed and implemented a full set of best practices, in compliance with specifications created by the standard. Oslo Water and Sewerage Works (Oslo VAV) has worked systematically to evolve its asset management system by standardizing work processes and operating procedures in its Business Process Management System, implementing good practice in infrastructure asset management, and by improved management and control of the private contractor that operates the wastewater treatment plant's processes and activities. This paper provides insight into Oslo VAV's asset management system, assessment of current practice vs. best practice for complying with the standard and high priority areas for improvement.
In the second half of the 2000s EPAL developed an Integrated Approach to Asset Management, designed according to the logic of PAS 55. Since then, Asset Management has been recognized as an invaluable function within the company and the portfolio of measures identified in the above-mentioned Integrated Approach has been implemented. With the release, in 2014, of ISO 55001, certification of the Asset Management System was made possible. Given the work already developed towards the deployment of Asset Management at EPAL, and because this had been based in the PAS 55 philosophy, EPAL was well positioned to obtain the ISO certification. The key challenges regarding the above-mentioned process were associated more with the implementation of the Asset Management at EPAL, rather than with the certification in itself. Because Asset Management was already an established practice at EPAL, key benefits of the certification are related to the documentation of such practice, which is something very important that was missing. Preparing for the certification also enabled the redesign of the Corporate Management System in order to meet the ISO and appendix SL requirements, making it more robust. And, of course, ISO 55001 certification became an asset in terms of Image and Reputation for EPAL!.
Águas de Portugal (AdP) group was responsible, during 2014, for the treatment of 547 million cubic meters of wastewater, operating more than 1,000 wastewater treatment plants (WWTPs) in Portugal. Electrical energy (EE) consumption was evaluated in 219 gigawatt hours, representing the largest part of OPEX in these plants. Improving energy efficiency is an ongoing challenge for AdP, being a major challenge for such huge number of facilities as well as for the large number of different technologies applied. However, this scenario has allowed, during the last five years, a systematic analysis and benchmarking of the operational information, and has outputted an important management tool regarding EE consumption, based on real data from more than 800 WWTP. This tool is used to leverage consumptions and identify efficiency opportunities, and represents an operational asset, not only for future EE consumptions prediction, but also as a driver for energy efficiency plans and to the design of new WWTPs.
The operational retrofits to improve nitrogen and phosphorus removal of AB process treating low concentration municipal wastewater in Luofang WWTP, in Shenzhen China, are described in this paper. The problems occurred during the 5-year operation since its start-up and the specific efforts devoted to the troubleshooting are presented roundly as well. As a result, a steady and efficient performance of AB process can be assured and a novel method of operation to improve phosphorus and nitrogen removal is developed. With the effluent quality of TN <14mg/L, NH3-N<2.5mg/L and TP<1.0mg/L, the operational retrofits are surely of practical value to those facilities that apply AB process and are poorly operated.
A study was made of the possibility of using natural materials (vermiculites, zeolite) and wastes (ash from the Partizansk Coal-Burning Power Plant) as sorbents in geochemical barriers to manage discharges (technogenic waters) from abandoned coal mines and reduce metal concentrations to established, acceptable standards. Vermiculite from the Kovdor deposit was shown to reduce the concentrations of Fe, Co, Ni, Cu, and Zn cations, in both direct and inverse soil column models, by between two and five times.
A Wastewater Risk Abatement Plan (WWRAP) has become an integral part in the operation of wastewater treatment plants across South Africa with the introduction of the Green Drop initiative. With each successive Green Drop season the WWRAP has become more of a focal point of the assessments and is intended to engender a more risk aware and risk averse philosophy into the operation of wastewater plants. The WWRAP, itself, is intended to be used as a tool to prioritize the deployment of limited resources and funds to achieve better compliance and management of wastewater treatment plants across the country. This is only effective if the method used for rating risk successfully identifies risks inherent on the plants. In essence the WWRAP will not achieve its objectives unless risks are properly identified. This paper explores the two successive WWRAPs produced by the eThekwini Municipality and the evolution of the risk rating systems employed. In 2011 the eThekwini Municipality’s WWRAP was based on a modified risk matrix as proposed in the Draft Guidelines for the development of WWRAPs by DWA and the WRC. While the results of this assessment generally correlated with the Department of Water Affairs’ Cumulative Risk Rating assessments, the rating system was based primarily on health targets and as a result was ineffectual as a tool for prioritization of resources. In 2012 with the next revision of the WWRAP there was a need to further ‘tweak’ the risk matrix used in order to more accurately reflect and identify risks on the various plants. This entailed increasing the complexity of the risk rating methodology and care was taken to ensure usability while still enhancing the efficacy of the risk assessment process. It was decided that ‘Administrative’ or ‘Reputational’ risk be taken into account when evaluating risk at the various plants and the risk assessment matrix was adjusted accordingly. It was decided that both administrative and reputational risk could be adequately represented by the influence that a particular risk had on the Affairs’ potential Green Drop score. Multiple permutations and approaches were evaluated to determine which method would best reflect the ‘on the ground situation’. Using the new rating system, a total of 1,235 low risks were identified over the previous year’s 913, medium risks numbered 223 over the 17 from 2011 and 105 high risks were identified for 2012 as compared to 2011 where no high risks were identified at all. The new rating system was thus deemed a more appropriate tool for the prioritization of resources for the municipality.
One route to establishing the economic level of odour abatement around a problem site requires that a monetary value per property be ascribed to the benefit of odour reduction. The literature on the monetary value of odour abatement was relatively sparse but a number of hedonic pricing studies into reductions in house prices produced an area weighted price reduction for the alleviation of impact in the region of £6,000 per property. No information could be obtained as to the level of odour or the degree of reduction involved. Studies into noise suggested a value of £350 per property per dB reduction, though with a high relative standard deviation. An odour-noise equivalence was established based on equal levels of community annoyance. A 1dB reduction in noise levels was equivalent to a reduction in odour concentration by a factor of 1.11. Applying the value per dB directly to odour results in a value for a 90% reduction in odour of £7,600 per property. A dispersion model was used to establish the relative reductions in odour levels associated with the hedonic pricing studies into odour. This produced the larger value of £790 per dB equivalent or £17,400 per property for a 90% reduction in odour levels.
The study's aim was to assess the impact of using water from Lake Abaya for irrigation and its impact on soil quality at Mirab Abaya, Ethiopia. Six water samples from the edge of Lake Abaya and 30 (18 irrigated and 12 rain-fed) composite soil samples from farm lands in Wajifo, Fura and Algae were collected. Analyses showed that the use of water from Lake Abaya will bring a soil salinity hazard in future. The soil analyses showed variations in space and time in the physico-chemical components in the study area. The highest salinity was reported from Algae, the closest site to the Lake. The highest soil alkalinity was reported from Wajifo, which has a long irrigation history. The irrigated soils reported higher salinity than the rain-fed soils, indicating that water from Lake Abaya can affect irrigated soil quality. In general, Lake Abaya water is not suitable for salt-sensitive crops and caution is required in using it for irrigation. HIGHLIGHTS
Irrigation water quality is equally important as drinking water quality for sustainable and efficient irrigation project implementation.;
If the irrigation water quality deteriorates it has its own impact on soil quality.;
Due to that, irrigation water quality assessments will be mandatory for the implementation of efficient irrigation projects.;
Chromium and its compounds are among the most well known strategic and critical materials in the world having a wide range of uses in the metals and chemical industries accompanied with chromium containing byproducts resulted in pollution of the environment. Chromium exists in the environment commonly in two oxidation states; Chromium (III) and chromium (VI), the later with the most toxic. The level of chromium contamination of water and soil samples in the peripheral of Abbay River were analyzed using inductively coupled plasma optical emission spectroscopy (ICP-OES), Horiba Scientific Ultima 2. The level of total chromium at the riparian of upper Abbay River both in the water and soil samples indicated higher concentrations near the wastewater discharge points from industries compared to the control site (above the industries). A sample taken near the discharge point of Habesha Tannery wastewater (S7), an average of 8.420 ± 5.409 mg/L total chromium was analysed, which is beyond the permissible limit to the surface water discharge set by WHO. It was also at this point, maximum chromium contamination in the soil was identified with an average of 232.465 ± 56.219 mg/kg. This was much higher than the control 7.60 ± 0.47 mg/kg. This study showed that the two tanneries discharge high chromium containing wastewater resulted from low treatment potential of the existing treatment plants established by the industries.
Drainage to lower water pressure is an effective measure for preventing and controlling water ingress when mining above a confined aquifer. The deep limestone aquifer in the Huaibei mining area, China, generally has high pressure, low permeability and variable water abundance, so it is difficult to meet single-borehole drainage requirements. In order to achieve good drainage, and take into account engineering and environmental protection requirements, a multi-objective optimization model of group borehole drainage was established. The model takes the minimization of single-hole flow and borehole numbers as the objective functions, and the drawdown in drainage boreholes and the water level control point as the constraint conditions. The particle swarm optimization algorithm was used to solve the model. The results indicate that, for a low permeability aquifer, measures such as using partially penetrating wells, increasing the number of drainage boreholes appropriately and reducing individual borehole yield have good drainage effects. The extent of drilling and amount of drainage are also relatively small. This is all to the good for the drainage. When the optimization results were applied to coal-face drainage in Huaibei the outcome was good.
Cyanobacteria blooms can complicate the economical or recreational use of waters. Many of the bloom forming species are also potential producers of harmful cyanotoxins. The standard method for quantifying phytoplankton biomass, based on inverted microscopy, has high accuracy and is the only one producing biomass results on taxonomic level, but it requires specialized expertise and is time-consuming. Phycocyanin (PC) pigment concentration has been proven as a useful proxy for the concentration of cyanobacteria. Since 2006, we have studied practical solutions of in-situ monitoring of cyanobacteria using PC fluorescence probes. We have studied two eutrophic lakes, Lake Littoistenjärvi and Lake Kuralanjärvi in southwestern Finland using stationary monitoring stations equipped with PC probes. The fluorescence results were compared to independent water samples analyzed using standard methods. The PC fluorescence was positively correlated to cyanobacteria biomass in both lakes. Using site-specific post-calibrations of biomass, PC fluorescence can be used to estimate the absolute biomass of cyanobacteria. The monitoring techniques used in these studies are an applicable and relatively low-cost method to monitor cyanobacteria abundance. With nearly real-time data transfer possibilities, they can be used in management and early warning applications to minimize the harmful effects of cyanobacteria blooms.
Soil is a powerful and active absorber of many substances, assumes the pressure of industrial and municipal emissions and waste, and performs the important role of a buffer and a detoxicant. It accumulates heavy metals, pesticides, hydrocarbons and other chemical polluting substances and due to the soil absorbing complex (SAC) strongly captures and protects natural waters and the atmosphere from harm. Applying sewage sludges in our research will enable us to strengthen the capacity of SAC and to reduce the toxicity of heavy metals when they enter a reservoir via a drain from anthropogenically polluted territory.
Hexavalent chromium Cr (VI) is a toxic heavy metal that discharged by many industries into the water streams. It is the most toxic form of chromium compound, which causes significant damage to receiving ecosystems. A microalgal species, Chlorella sp., was used as a biosorbent material to remove Cr (VI) from Cr-contaminated effluents. Furthermore, different variables: pH, temperature, contact time, Cr (VI) concentration and algal dose, were optimized in order to determine the optimum conditions that achieve the highest removal efficiency. The optimization process was achieved through two steps: one factor at a time (OFAT) experiments followed by 25 general full factorial. Moreover, molecular identification was performed using 18S rRNA in order to demonstrate the species of Chlorella, and it was identified as Chlorella sorokiniana. The highest chromium removal efficiency of 99.6793% was achieved at 100 ppm Cr (VI) after three days' contact time. Chlorophyll ‘a’ estimation as a growth indicator stated that Chlorella sorokiniana can tolerate 100 ppm Cr (VI) for three days' exposure. The results suggested that Chlorella sorokiniana is a good biosorbent material and it distinguished by its high ability to uptake Cr (VI) from solutions.
Thermal stripping – acid absorption is a novel technology recently developed to recover ammonia as marketable ammonium sulfate granules from anaerobic digester effluent. Taking a large-size dairy farm in New York State, USA, as an example, this study evaluates the costs and benefits of ammonia recovery from a recirculation line of mesophilic anaerobic digesters. Option 1 is the baseline without ammonia recovery. Option 2 is to draw digester effluent at 28% of the liquid manure loading rate, heat to 101 °C for ammonia recovery, and return the ammonia-recovered dairy manure to the digesters. Under option 2, the returned hot manure eliminates the need to heat the digesters. Option 3 is similar to Option 2, but the recirculation rate is only 14% of the manure loading rate. In this case, additional heating is needed for the digesters. Engineering unit cost and revenue models are developed for the thermal stripping – acid absorption process. Options 2 and 3 have benefit/ cost ratios of 1.90 and 1.86, respectively. Option 2 produces greater net present value (NPV) ($1.34 million) than Option 2 ($0.72 million), while Option 1 yields a negative NPV (_$0.23 million). Ammonia recovery on this farm can create 1.5–3 jobs. Labor costs account for 62–70% of the total operating costs. Option 2 can generate a benefit of $0.018/L manure digestate or $0.50/d/cow. Any uncertainties relating to NPV and benefit/cost ratio are mainly associated with the sale price of ammonium sulfate and hourly wage rate.
As water abundance of aquifer of coal roof significantly influences roof water hazard, evaluating and grading the degree of water abundance are important in practical application. By analyzing the influencing factors of water abundance of aquifer, an evaluation index system and a grading standard for the water abundance were established integrating quantitative and qualitative indexes. Meanwhile, according to the grey relation characteristics of the major factors influencing water abundance, a multi-factor evaluation model for water abundance was constructed based on grey relational analysis and analytic hierarchy process. The model can objectively reveal the influences of the multiple factors on the evaluation of water abundance. Furthermore, the method was verified by comprehensively evaluating the water abundance of the aquifer of coal roof in a working face of Pingshuo Coal Mine in Shanxi, China using the model. The method provides basis for the research on the evaluation of water abundance of aquifer in coal roof.
An eSOS (emergency Sanitation Operation System) Smart Toilet experimental prototype, aimed at improving the provision of safe sanitation in emergency settings, was field tested in a temporary settlement in Tacloban City, Philippines. The design, usage, and user acceptance of the toilet were all evaluated. Quantitative and qualitative data were collected through interviews and questionnaires, supported by the research-team’s observations. The survey results indicated that 98% of users (both first-time users and those who tried it a few times) intended to use the toilet again. There were more features that the users liked than disliked. The in-built water supply and user-operated smart toilet features were liked, but the bad smell was disliked. User-operated smart features were an important factor in user acceptance although they were not the main incentives. Key recommendations are to improve the toilet’s design to address the odor and cleanliness issues, make handwashing more convenient, and lower the height of the toilet bowl.
This paper deals with the concept of 'community acceptance testing (CAT)' which is perhaps a new concept in the water supply sector. To understand this it is necessary to accept the water supply system as a product of engineering works and water as social goods. While the engineering approach verifies the product against predefined specifications, the CAT validates the capability of that product to satisfy user expectations. In the water supply, sanitation and hygiene sector, there is a culture of verification, but validation should also be given due importance. The validation process is based on user stories and is done before handing over the project to the community. It establishes the community's supremacy over system decision-making and service delivery. The CAT approach promotes the designing of community-engineered systems.
To overcome the problem of water scarcity in a rural karst area located in Gunung Sewu, Yogyakarta, Indonesia, water from an underground cave (Bribin Cave) is pumped and distributed to the people. Since karst aquifers are often considered as highly vulnerable to contamination from human activities, potential problems caused by current sanitation and hygiene practices in the recharge region must be anticipated. About 90% of the people in the recharge area use pour flush syphon toilets with poorly designed septic tanks and the rest have simple pit latrines. However, the existing septic tanks are very poorly designed and are actually only improved infiltration pits.
One possible option to reduce the risk of aquifer contamination is to promote sustainable sanitation, which combines hygienic aspects with recycling of nutrients from human feces and urine. Sustainable sanitation comprises different technologies including low cost technology, which can be afforded by the community and provide economic benefit to the low income inhabitants in Gunung Sewu. The technology proposed is urine diverting and composting toilets. This paper presents the existing condition of rural domestic wastewater treatment and the opinion/ acceptance of the community in karst area of Gunung Sewu towards urine diverting and composting toilets. The results of the survey shows that although the acceptance of using the composting toilet is not high (25% to 43%), the interest of the community in using the end product is relatively high. While the acceptance of composting fertilizer from feces (humanure) ranges from 37% to 57%, urine fertilizer attracts 42%-71% respondents' interest.