Cost Of Wastewater Treatment Research Articles

Wastewater recycling technology for fermentation in polyunsaturated fatty acid production

To reduce fermentation-associated wastewater discharge and the cost of wastewater treatment, which further reduces the total cost of DHA and ARA production, this study first analyzed the composition of wastewater from Aurantiochytrium (DHA) and Mortierella alpina (ARA) fermentation, after which wastewater recycling technology for these fermentation processes was developed. No negative effects of DHA and ARA production were observed when the two fermentation wastewater methods were cross-recycled. DHA and ARA yields were significantly inhibited when the wastewater from the fermentation process was directly reused. In 5-L fed-batch fermentation experiments, using this cross-recycle technology, the DHA and ARA yields were 30.4 and 5.13gL−1, respectively, with no significant changes (P>0.05) compared to the control group, and the water consumption was reduced by half compared to the traditional process. Therefore, this technology has great potential in industrial fermentation for polyunsaturated fatty acid production.

Optimisation of filter design and operation for wastewater treatment sludge

Abstract Wastewater treatment (WWT) produces a biomass or sludge that must be dewatered in order to reduce its volume and subsequent disposal costs. Although WWT sludges can be compressed to high solids concentrations under enough force, they are also highly impermeable such that it takes a long time to remove the water. This leads to low throughputs for dewatering devices such as filters and centrifuges, which means that dewatering contributes a significant proportion of the overall cost of WWT. Improvements to throughput at a given final solids concentration or higher solids concentrations at a given throughput can represent substantial cost savings to the WWT industry. Recent developments in understanding the highly compressible nature of WWT sludges have led to a fundamentally rigorous description of their dewaterability. In addition, methods have been developed for measuring their compressibility and permeability over a broad range of solids concentrations, which allows the prediction of their behaviour using models of dewatering devices. In this work, the dewatering properties of an Australian WWT sludge are used in a validated model of flexible-membrane or diaphragm plate-and-frame filtration. The model is used to optimise the filtration time to give the maximum throughput for various values of cavity width and handling time. Flexible-membrane filtration is versatile in that there is a given squeeze time to reach a certain solids concentration for each fill time, but there is only one combination of fill and squeeze that maximises the throughput. This work shows that, due to the highly impermeable nature of WWT sludges, the maximum throughput is when the fill time is the shortest such that filter presses for WWT sludges are optimally operated by loading enough sludge to fill the press and then immediately squeezing. For slow-filtering materials such as WWT sludges, the maximum throughput varies inversely with cavity width such that small cavity widths, within the constraints of cake release, are preferable.

Spatially resolved air-water emissions tradeoffs improve regulatory impact analyses for electricity generation

Coal-fired power plants (CFPPs) generate air, water, and solids emissions that impose substantial human health, environmental, and climate change (HEC) damages. This work demonstrates the importance of accounting for cross-media emissions tradeoffs, plant and regional emissions factors, and spatially variation in the marginal damages of air emissions when performing regulatory impact analyses for electric power generation. As a case study, we assess the benefits and costs of treating wet flue gas desulfurization (FGD) wastewater at US CFPPs using the two best available treatment technology options specified in the 2015 Effluent Limitation Guidelines (ELGs). We perform a life-cycle inventory of electricity and chemical inputs to FGD wastewater treatment processes and quantify the marginal HEC damages of associated air emissions. We combine these spatially resolved damage estimates with Environmental Protection Agency estimates of water quality benefits, fuel-switching benefits, and regulatory compliance costs. We estimate that the ELGs will impose average net costs of $3.01 per cubic meter for chemical precipitation and biological wastewater treatment and $11.26 per cubic meter for zero-liquid discharge wastewater treatment (expected cost-benefit ratios of 1.8 and 1.7, respectively), with damages concentrated in regions containing a high fraction of coal generation or a large chemical manufacturing industry. Findings of net cost for FGD wastewater treatment are robust to uncertainty in auxiliary power source, location of chemical manufacturing, and binding air emissions limits in noncompliant regions, among other variables. Future regulatory design will minimize compliance costs and HEC tradeoffs by regulating air, water, and solids emissions simultaneously and performing regulatory assessments that account for spatial variation in emissions impacts.

Lithium recovery from shale gas produced water using solvent extraction

Shale gas produced water is hypersaline wastewater generated after hydraulic fracturing. Since the produced water is a mixture of shale formation water and fracturing fluid, it contains various organic and inorganic components, including lithium, a useful resource for such industries as automobile and electronics. The produced water in the Marcellus shale area contains about 95 mg/L lithium on average. This study suggests a two-stage solvent extraction technique for lithium recovery from shale gas produced water, and determines the extraction mechanism of ions in each stage. All experiments were conducted using synthetic shale gas produced water. In the first-stage, which was designed for the removal of divalent cations, more than 94.4% of Ca2+, Mg2+, Sr2+, and Ba2+ ions were removed by using 1.0 M di-(2-ethylhexyl) phosphoric acid (D2EHPA) as an extractant. In the second-stage, for lithium recovery, we could obtain a lithium extraction efficiency of 41.2% by using 1.5 M D2EHPA and 0.3 M tributyl phosphate (TBP). Lithium loss in the first-stage was 25.1%, and therefore, the total amount of lithium recovered at the end of the two-step extraction procedure was 30.8%. Through this study, lithium, one of the useful mineral resources, could be selectively recovered from the shale gas produced water and it would also reduce the wastewater treatment cost during the development of shale gas.

Controlling seawater intrusion by treated wastewater recharge. Numerical modelling and cost-benefit analysis (CBA) at Korba case study (Cap Bon, Tunisia)

Treated wastewater (TWW) reuse for managed aquifer recharge (MAR) is becoming an important measure for integrated water management in areas with water scarcity. Among reuse applications, interest in aquifer recharge to control seawater intrusion in coastal aquifers is growing worldwide. At the Korba-Mida aquifer (Tunisia), local aquifer recharge with treated urban wastewater has taken place through three infiltration ponds since 2008. An ex post Cost–Benefit Analysis (CBA) is presented to assess the recharge impact at the groundwater level in a coastal aquifer after 3 years of recharge. A MODFLOW-based groundwater numerical model was developed to guide the impact assessment. The local model results showed that the recharged volume was slightly higher than extractions. The economic results indicated that the internal rate of returns accounted for 14.46%, while the discount rate of project investment was 4%. According to the sensitivity analysis, this project is feasible for the present wastewater treatment cost (0.1 TND per m3, Tunis Dinar) and up to 0.25 TND per m3. Possible effects on groundwater quality as an added influential final externality cost were not considered.

Integrated treatment processes for coal-gasification wastewater with high concentration of phenol and ammonia

Coal gasification wastewater treatment process, especially for the wastewater produced by pressurized fixed bed gasification, has already become one of the key factors which restrict the development of coal chemical industry. This wastewater has all along been regarded as one of the most difficult to be treated with because of the high concentration of phenol and ammonia in it. The most efficient treatment method is distillation and extraction. Phenols and ammonia are recovered as products. However, energy consumption, in the form of low-pressure steam and mid-pressure steam, is relatively high in this process. Technological and economic performance of the wastewater treatment process developed by South China University of Technology (SCUT) was analyzed in this paper. Two integration processes based on SCUT wastewater treatment process are proposed in which solvent recovery system is thermally integrated. The results indicate that the energy consumption via these integrations is decreased by approximately 18% compared with the conventional SCUT process. The cost of wastewater treatment can be reduced to 0.2 CNY/ton of wastewater. An on-site trial-plant is constructed to test the feasibility of the processes. The competitiveness of the technology for wastewater treatment is improved.

Construction and Operation Costs of Wastewater Treatment and Implications for the Paper Industry in China.

This paper aims to develop a construction and operation cost model of wastewater treatment for the paper industry in China and explores the main factors that determine these costs. Previous models mainly involved factors relating to the treatment scale and efficiency of treatment facilities for deriving the cost function. We considered the factors more comprehensively by adding a regional variable to represent the economic development level, a corporate ownership factor to represent the plant characteristics, a subsector variable to capture pollutant characteristics, and a detailed-classification technology variable. We applied a unique data set from a national pollution source census for the model simulation. The major findings include the following: (1) Wastewater treatment costs in the paper industry are determined by scale, technology, degree of treatment, ownership, and regional factors; (2) Wastewater treatment costs show a large decreasing scale effect; (3) The current level of pollutant discharge fees is far lower than the marginal treatment costs for meeting the wastewater discharge standard. Key implications are as follows: (1) Cost characteristics and impact factors should be fully recognized when planning or making policies relating to wastewater treatment projects or technology development; (2) There is potential to reduce treatment costs by centralizing wastewater treatment via industrial parks; (3) Wastewater discharge fee rates should be increased; (4) Energy efficient technology should become the future focus of wastewater treatment.

Joint pollution control in the Lake Tai Basin and the stabilities of the cost allocation schemes

This paper provides insights into the allocation of benefits derived from joint wastewater treatment in the Lake Tai Basin of China and the acceptability and stability of different cost allocation schemes in a trans-jurisdictional water system context. First, the wastewater treatment cost function is estimated and coalition costs are compared to the cost of stand-alone wastewater treatment in each province. Second, two standard and five game theoretical cost allocation schemes are applied to the grand coalition. Results suggest that a cost savings of US $46.46 million can be obtained by forming a grand coalition. All allocation schemes were found to be acceptable. Results also suggest that both Shanghai and Jiangsu Province would prefer a proportional allocation scheme based on pollutant discharge, because it would offer them the largest cost savings. But this allocation scheme is the least stable one. Based on the criterion of stability, the Nash-Harsanyi scheme emerges as providing the optimal allocation. Finally, calculation of power and stability indexes suggests Jiangsu Province as an agent is critical to the success of grand coalition formation.

Towards Rational Optimization of a Wastewater Treatment Electrocatalyst for the Chlorine Evolution Reaction Using a Method for Finding Active Sites on Brush Coated Samples

Electrocatalytic systems show promise for addressing global environmental problems by offering waste free mechanisms for processes like fuel production and modular wastewater treatment in developing countries. Although several catalysts have been developed for these tasks their catalytic mechanisms are poorly understood which makes rational optimization and design of a given electrocatalyst a very difficult undertaking. This problem is universal, but it is crucially important for wastewater treatment in the developing world. Currently, 4.2 billion people lack access to adequate sanitation; poor sanitation is now the largest killer of children under five. Human waste pollution in natural waters will, according to UNESCO, lead to two thirds of the world’s population entering a state of water scarcity by 2025. Most water pollution issues are localized in the developing world where human wastewater treatment infrastructure is poor or nonexistent. For practical reasons, developed world style solutions to wastewater problems are largely infeasible in the developing world. For example, it is an enormous challenge to lay sewer lines in cities like Delhi where millions of people live in buildings often constructed without rebar. It is therefore attractive to consider a technological solution to this problem where water is treated and recycled or discharged on site without sewer lines. This would reduce the demand for water and eliminate the largest source of water pollution without displacing millions of people to dig sewer lines. One convenient option for onsite wastewater treatment is electrochemical chlorine evolution from chloride naturally found in urine. This technology is especially beneficial because in addition to providing oxidation power to mineralize organics, chlorine can also remove nitrogen compounds through breakpoint chlorination and phosphorous compounds through cathodic electroplating of hydroxyapatite. All of this can be accomplished while recycling water with no external input of chemicals, with off grid solar energy, and a sanitary flush toilet and hand-wash station. Unfortunately, good chlorine evolution reaction (CER) electrocatalysts for wastewater treatment need to be highly stable to withstand the harsh wastewater environment, and the only catalyst so far discovered that has met this requirement is TiO2 coated IrO2 which is far too expensive for applications in the developing world. One obvious way to make these electrodes affordable is to optimize their efficiency such that much less material is needed to treat the same amount of wastewater. In recent years, active site based optimization has proved to be an attractive strategy for catalytic optimization. Catalytic “active sites” are regions of a catalyst that have a “sweet spot” of topography and/or chemical composition which leads to heightened catalytic activity. This sweet spot has the chemical and physical characteristics to bind neither reactant nor product neither too tightly nor too loosely and can stabilize intermediates. This method of optimization involves first finding the structure or chemical composition that best catalyzes the reaction of interest and then optimizing the catalyst to maximize the active sites. Unfortunately, there are not currently methods of active site discovery for the general catalyst and complexity in identifying an active site becomes high when multiple sites work together or where both structure and chemical composition play strong roles in the observed activity. In our work, we have used a scanning electrochemical microscope to identify electrocatalytic hotspots on a brush coated sample and then used electron microscopy and energy dispersive x-ray spectroscopy to determine what is unique about structure and function of the hotspots. With this information we were able to determine that the thickness of the overlying TiO2 layers play a crucial role in the CER active site formation. By tuning the TiO2 thickness we then rationally engineered a catalyst that is as much as 20 times more active than the state of the art IrO2 CER catalyst. We believe that this increase in activity has to do with the strain that the underlying IrO2 puts on the overlying TiO2 layer. This theory is consistent with computational results that indicate the Metal-O bond strength is a crucial indicator of CER activity. This innovation could lead to a significant decrease in the amount Ir needed to treat wastewater and therefore the cost of electrocatalytic wastewater treatment could become affordable in the developing world. Furthermore, using this method, we were able to increase the activity of a catalyst that has been around for decades by 20 fold by interrogating the brush coated version of the catalyst. It is therefore possible that this active site based optimization method could be used to optimize the numerous other catalysts that could be prepared by brush coating.

Recycling of pad-batch washing textile wastewater through advanced oxidation processes and its reusability assessment for Turkish textile industry

Water management, recycling, and reuse in industrial facilities is a hot topic in today's growing economy because of declining water levels, regulation pressure, and increasing cost of wastewater treatment and supply. In this study, recyclability and direct reuse of washing/bleaching wastewater from reactive dyeing of cotton fabric through advanced oxidation processes (AOPs) (O3, UV-O3, O3-H2O2, and O3-H2O2-UV) has been investigated. Dyeing trials with treated wastewater were carried out at laboratory scale and no undesirable effects on fabric dyeing quality (ΔE ≤ 1 for color variation) were found for all AOPs. The O3-H2O2-UV process removed COD at a higher rate (55%) than other studied AOPs while color removal was similar (>95%). In pad batch washing/rinsing, 100% water could be recycled (i.e.40% of the total water consumption at facility), reducing fresh water demand for washing operations. Despite this, energy saving, reduced salt consumption and reduction of the cycle time are in favor of recycling/reusing the washing/rinsing effluent.

Cluster analysis of urban water supply and demand: Toward large-scale comparative sustainability planning

The sustainability of urban water systems is often compared in small numbers of cases selected as much for their familiarity as for their similarities and differences. Few studies examine large urban datasets to conduct comparisons that identify unexpected similarities and differences among urban water systems and problems. This research analyzed a dataset of 142 cities that includes annual per capita water use (m3/yr/cap) and population. It added a 0.5° grid annual water budget value (P-PET/yr) as an index of hydroclimatic water supply. With these indices of urban water supply and demand, we conducted a hierarchical cluster analysis to identify relative similarities among, and distances between, the 142 cases. While some expected groupings of climatically similar cities were identified, unexpected clusters were also identified, e.g., cities that use water at greater rates than local climatic water budgets provide. Those cities must seek water from greater distances and greater depths. They face greater water and wastewater treatment costs. To become more sustainable they must increase water use efficiency, demand management, reuse, and recycling. The significance of the population variable suggests that adding other explanatory socio-economic variables, as well as more precise water system indices, are logical next steps for comparative analysis of urban water sustainability.

Application of Magnetic Hydrogel for Anionic Pollutants Removal from Wastewater with Adsorbent Regeneration and Reuse

AbstractA novel magnetic hydrogel coupling with a wastewater treatment prototype is proposed in this study for the removal of various types of anionic pollutants from wastewater. Within 5 min of kinetic studies, 97.5, 99.9, 100.0, 81.7, and 98.9% of Cr(VI), amaranth, methyl orange, nitrate, and phosphate were removed from wastewater, whereas these adsorbed anions were desorbed to varying extents using NaCl for 15 min. The maximum adsorption capacities of Cr(VI), amaranth, methyl orange, nitrate, and phosphate were 205 mg/g, 830 mg/g, 1,390 mg/g, 188 mg/g, and 227 mg/g, respectively. An industrial wastewater treatment prototype was developed featuring a magnetic separation unit for the recovery of spent magnetic hydrogel. A separation efficiency over 98% can be maintained throughout 60 adsorption-desorption cycles of Cr(VI) wastewater treatment. The estimated wastewater treatment cost in consideration of chemical usage only is USD 0.58/m3. The chemical cost of the treatment is comparatively less expen...

Wave generation in subsurface aeration system: a new approach to enhance mixing in aeration tank in wastewater treatment

Energy crises in the early 1970’s created awareness of the cost of wastewater treatment and the energy required for each stage. Aeration process was the focal point of energy saving research, due to its high power consumption, which led to change the use of coarse bubble aeration system to fine bubble aeration. Until now, all commercially existing aeration systems use continuous airflow. Meanwhile, the system investigated in this paper uses pulsation flow to reduce energy consumption in aeration tank by improving oxygen transfer efficiency (OTE). In this study, a new innovative air injection method is proposed to improve OTE in the aeration basin without extra power depletion. The suggested method is simply to inject air alternatingly from two adjacent diffusers into the aeration system. It was found that OTE was improved using this method. This improvement could be attributed to water agitation caused by transient condition operation. Timing the separation between two injections is a very important aspect of the proposed system. The optimum separation time was found by varying the timing between these injections. The highest OTE was obtained at a separation time of 1.5 s and a volumetric flow rate of 42 LPM with a 57.1% enhancement in comparison to the steady state traditional aeration system.

Performance Evaluation of Alternative Disinfectants in Reducing Microbial Contamination of Vegetables Supplied from City of Kermanshah

Background: In recent decades, due to the scarcity of fresh water resources and high costs of wastewater treatment, cases of irrigation of cultivation of vegetables using raw sewage and polluted effluents or the use of human and animal faeces have been reported. Vegetables are important sources of exposure of human pathogenic pathogens such as fecal coliforms. The aim of this study was to evaluate the performance of three different disinfectant on several kinds of vegetables that would normally be released in Kermanshah. Methods: In this cross sectional study, 180 randomly selected vegetable samples were collected from mobile and fixed stores of vegetables in Kermanshah. Then, to evaluate the effectiveness of disinfectants in eliminating microbial samples, three types of disinfectants containing active ingredient Benzalconium chloride, were studied. Heterotrophic plate count (HPC) surface culture method, coliform count (VRBA) Violet Red Bile Agar purplate method and Yeast Glucose Chloramphemicole Agar (YGCA) surface culture method was used in order to count the microbial load. Results: The findings of this study suggest that the overall average performance of all three disinfectants was less than 75 and most disinfection efficiency was observed in two-fold concentrations of proposed by manufacturer. Based on the analysis of the resulting data, disinfectants examined in this study had an average efficiency of 76.13 for the removal of coliforms as an indicator of gram-negative bacteria and 100 for the removal of Streptococcus bacteria as indicators gram positive bacteria. Conclusion: Disinfection can not solely guarantees the maintaining the health of the consumer. We could have declared that recommended disinfection conditions and existing facilities can effectively reduce the microbial load of vegetables. However, preparing vegetables from safe and ensure proper burial are recommended. Moreover, consuming the raw vegetables in sensitive seasons and precarious conditions should be avoided.

The yield and decay coefficients of exoelectrogenic bacteria in bioelectrochemical systems

In conventional wastewater treatment, waste sludge management and disposal contribute the major cost for wastewater treatment. Bioelectrochemical systems, as a potential alternative for future wastewater treatment and resources recovery, are expected to produce small amounts of waste sludge because exoelectrogenic bacteria grow on anaerobic respiration and form highly populated biofilms on bioanode surfaces. While waste sludge production is governed by the yield and decay coefficient, none of previous studies have quantified these kinetic constants for exoelectrogenic bacteria. For yield coefficient estimation, we modified McCarty's free energy-based model by using the bioanode potential for the free energy of the electron acceptor reaction. The estimated true yield coefficient ranged 0.1 to 0.3 g-VSS (volatile suspended solids) g-COD−1 (chemical oxygen demand), which is similar to that of most anaerobic microorganisms. The yield coefficient was sensitively affected by the bioanode potential and pH while the substrate and bicarbonate concentrations had relatively minor effects on the yield coefficient. In lab-scale experiments using microbial electrolysis cells, the observed yield coefficient (including the effect of cell decay) was found to be 0.020 ± 0.008 g-VSS g-COD−1, which is an order of magnitude smaller than the theoretical estimation. Based on the difference between the theoretical and experimental results, the decay coefficient was approximated to be 0.013 ± 0.002 d−1. These findings indicate that bioelectrochemical systems have potential for future wastewater treatment with reduced waste sludge as well as for resources recovery. Also, the found kinetic information will allow accurate estimation of wastewater treatment performance in bioelectrochemical systems.

Optimum synthesis of an electrodialysis framework with a Background Process II: Optimization and synthesis of a water network

The water-energy nexus considers the relationship between water and energy resources. The tightening environmental regulations and social pressures have made it necessary to develop processes that are conservative with respect to both these resources. In the first part of this series, a multi-contaminant electrodialysis (ED) model was developed. In this second part of the series, the application of the developed ED model for the partial purification of contaminated water within a water network synthesis (WNS) and optimization problem is explored. The optimization model is based on a superstructure framework, where the objective is to minimize freshwater consumption, wastewater production, energy consumption and the operating and capital costs involved in the process integration. A comparison is made between the framework presented in this manuscript and the more common black box model, which simplifies regeneration units to linear expressions. The results show that the black box approach can lead to inaccuracies of up to 85% in the costing of regeneration units. ED optimization performed within the WNS problem results in a more comprehensive design than if the design is developed as a standalone model. Furthermore, it is shown that there are significant environmental and financial benefits in the simultaneous minimization of water and energy in water networks. When applied to a pulp and paper case study, the integrated approach resulted in 38% reduction in total freshwater consumption and 67% savings in wastewater treatment costs.

Cultivation of Chlorella vulgaris in wastewater with waste glycerol: Strategies for improving nutrients removal and enhancing lipid production

To improve nutrients removal from wastewater and enhance lipid production, cultivation of Chlorella vulgaris in wastewater with waste glycerol generated from biodiesel production using scum derived oil as feedstock was studied. The results showed that nutrients removal was improved and lipid production of C. vulgaris was enhanced with the addition of waste glycerol into wastewater to balance its C/N ratio. The optimal concentration of the pretreated glycerol for C. vulgaris was 10gL−1 with biomass concentration of 2.92gL−1, lipid productivity of 163mgL−1d−1, and the removal of 100% ammonia and 95% of total nitrogen. Alkaline conditions prompted cell growth and lipid accumulation of C. vulgaris while stimulating nutrients removal. The application of the integration process can lower both wastewater treatment and biofuel feedstock costs.

Decentralized Low Cost Wastewater Treatment Plant Based on Phytoremediation and Bagasse Fly Ash as Natural Filtering Media

Decentralized Low Cost Wastewater Treatment Plant Based on Phytoremediation and Bagasse Fly Ash as Natural Filtering Media

Added-value from linking the value chains of wastewater treatment, crop production and bioenergy production: A case study on reusing wastewater and sludge in crop production in Braunschweig (Germany)

The limited availability of natural water resources and dependency on mineral fertilizer challenge agricultural value chains in arid and nutrient-poor areas. Reusing wastewater in agriculture may help and could reduce costs and lead to increased added-value. The objective of this analysis is to assess the economic impact of linking the value chains of wastewater treatment, crop production and the generation of bioenergy by reusing treated municipal wastewater and sludge. The assessment was based on the cost/benefits and the added-value from the reused wastewater by the Braunschweig Wastewater Association (Germany). Benefits were assessed by comparing the costs of wastewater irrigation and sludge application with conventional disposal options, as well as comparing the costs of irrigation and fertilization with treated wastewater to groundwater irrigation and mineral fertilization. The added-value was calculated by ascertaining the remunerations received by the stakeholders in the various value chains. The results indicate that the reuse of wastewater and sludge results in: (a) the development of linked regional value chains; (b) lower costs of wastewater treatment and sludge disposal; (c) higher profitability and added-value in crop production; and (d) a high share (77%) of regional added-value. However, the results also show that the reuse of wastewater and sludge within linked value-chains can restrict actors and lead to crowding out effects on the added-value. Agricultural reuse schemes should provide additional opportunities that enable farmers to increase their scope of possibilities and compensate for missed economic potential.

Valuing environmental damage remediation and liability using value estimates for ecosystem services

The European Environmental Liability Directive aims to ensure that damaged habitats are restored where possible, but allows for complementary remediation with replacement habitat where restoration is not possible within a reasonable time. It also allows for compensatory remediation of the resource based on an assessment of environmental values in cases where there are interim social losses. This paper concurs with the argument that physical remediation without consideration of social values can fail to be equivalent to the resource that has been lost. Using, as a case study, a river in Ireland, it demonstrates that estimating social value can be challenging in practice, noting also differences between the value of environmental gains and losses. The paper argues that estimates of final ecosystem service values, including wastewater treatment costs, can provide a measure of social value and makes a case for the systematic collection of these data to inform decision-making.