Water recycling goes mainstream Harris-Lovett, Sasha
Science (American Association for the Advancement of Science),
01/2024, Volume:
383, Issue:
6678
Journal Article
Peer reviewed
Public health and public relations are key to successful potable water reuse programs
No other resource is as necessary for life as water, and providing it universally in a safe, reliable and affordable manner is one of the greatest challenges of the twenty-first century. Here, we ...consider new opportunities and approaches for the application of nanotechnology to enhance the efficiency and affordability of water treatment and wastewater reuse. Potential development and implementation barriers are discussed along with research needs to overcome them and enhance water security.
In this study, the effectiveness of integrating electrocoagulation (EC) and ultrafiltration (UF) membranes for palm oil mill effluent (POME) wastewater treatment was investigated. The impact of ...various parameters on contaminant removal efficiency, including electrode configuration (monopolar and bipolar), number of anodes, agitation rate, and current density, was studied. The findings demonstrated that using bipolar (BP) electrodes in the EC reactor improved coagulation efficiency. However, an increase in agitation rate led to a decrease in removal efficiency. The electrode configuration of 2A-2C–2B achieved high contaminant removal with a lower electrode consumption compared to the 4A-2C and 4A-2C–2B configurations. The removal efficiencies for total dissolved solids (TDS), total suspended solids (TSS), chemical oxygen demand (COD), and biological oxygen demand (BOD) were 59.1%, 99.9%, 96.8%, and 96%, respectively. The operating cost for the electrode configuration of 2A-2C–2B was estimated to be 2.71 US$ m−3 at an effluent capacity of 50 m3 d−1 and 20 h d−1 of operating time, while the energy requirement was 6.20 kWh m−3. An increase in operating time from 5 to 24 h d−1 raised the specific operating cost from 2.17 to 2.85 US$ m−3. This study provides valuable insights into optimizing EC and UF processes for POME wastewater treatment, which could have significant implications for sustainable industrial practices.
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•Integration of electrocoagulation (EC) and ultrafiltration (UF) was used for POME treatment.•Influence of electrode configuration and current density on effluent quality studied.•Electrode 2 A-2C–2B achieved high contaminant removal with lower electrode consumption.•TDS, TSS, COD, BOD removed by 59.1%, 99.9%, 96.8%, and 96%, respectively.•Operating cost was 2.71 US$ m−3 at 50 m3 d−1 effluent capacity and energy demand of 6.20 kWh m−3.
Technological innovation that is incongruous with established social rules and practices is often confronted with strong skepticism and a lack of societal legitimacy. Yet, how the early actors in a ...new technological field create legitimacy for new products is not well researched. This paper addresses this gap by proposing an analytical framework for the early technology legitimation phase that combines recent insights from innovation studies and institutional sociology. Both literatures agree that technology legitimation depends on a complex alignment process in which the technology and its institutional context mutually shape each other. Innovation system studies recently proposed to explore these processes in more detail. So far, this literature has mainly treated legitimacy as an outcome of overall system maturation and has not ventured into assessing legitimation as an active process. The framework we put forward in this paper conceptualizes technology legitimation as being enacted by different actors in a technological innovation system through specific forms of institutional work. This framework is illustrated with a case study on potable water reuse, in this case the injection of treated wastewater into drinking water reservoirs — a technology most consumers confront with revulsion. California is among very few regions worldwide where this technology is becoming common practice. Interviews with 20 key stakeholders and content analysis of 124 newspaper articles reveal how technology proponents worked on legitimizing this controversial technology by engaging in system building and institutional work at various levels. We outline how the legitimation process interrelates with other core development processes of a technological innovation system and discuss how our framework informs recent work in innovation and transition studies.
•Legitimation of radically new technologies is not well explained in the literature.•Institutional work and innovation studies are combined in a new legitimacy framework.•A case study on potable water reuse in California illustrates the framework.•Legitimacy for the innovation resulted from early actors' targeted institutional work.•Embedded agency in embryonic innovation systems explains successful legitimation.
This paper evaluates the metabolism-based performance of a number of centralised and decentralised water reuse strategies and their impact on integrated urban water systems (UWS) based on the nexus ...of water-energy-pollution. The performance assessment is based on a comprehensive and quantitative framework of urban water metabolism developed for integrated UWS over a long-term planning horizon. UWS performance is quantified based on the tracking down of mass balance flows/fluxes of water, energy, materials, costs, pollutants, and other environmental impacts using the WaterMet
2
tool. The assessment framework is defined as a set of key performance indicators (KPIs) within the context of the water-energy-pollution nexus. The strategies comprise six decentralised water reuse configurations (greywater or domestic wastewater) and three centralised ones, all within three proportions of adoption by domestic users (i.e. 20, 50, and 100%). This methodology was demonstrated in the real-world case study of San Francisco del Rincon and Purisima del Rincon cities in Mexico. The results indicate that decentralised water reuse strategies using domestic wastewater can provide the best performance in the UWS with respect to water conservation, green house gas (GHG) emissions, and eutrophication indicators, while energy saving is almost negligible. On the other hand, centralised strategies can achieve the best performance for energy saving among the water reuse strategies. The results also show metabolism performance assessment in a complex system such as integrated UWS can reveal the magnitude of the interactions between the nexus elements (i.e. water, energy, and pollution). In addition, it can also reveal any unexpected influences of these elements that might exist between the UWS components and overall system.
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•Correlations of water reuse to local water resource and GDP levels were analysed.•Centralized water reuse framework and utilization patterns were identified.•Characteristics and ...applications of centralized water reuse systems were discussed.•A case study on the multiple-application water reuse model is conducted.•The importance of water reuse for urban sustainable management was highlighted.
In the context of rapid urbanization and water shortage, many cities of the world, especially megacities in rapidly developing zones, have urgent needs in improving their sustainable water management without compromising the local socioeconomic development. Water reuse has been increasingly recognized as a sustainable water management strategy. The results of this paper have shown that the development of water reuse in China is found to have positive correlations to local water resource availability and GDP levels, and the water reuse rate in some megacities has already reached 35–60%. Centralized water reuse systems have widely gained favor. Thus, a centralized water reuse framework with three utilization patterns is proposed. Particularly, a multiple-utilization model that applies a hierarchical use structure is found to be viable for meeting multiple water quality requirements. Other patterns address environmental and cascading ways in maximizing the value of reclaimed water use. A case study in a Chinese megacity, Tianjin, is demonstrated where a large-scale centralized water reuse project with a multiple barrier treatment approach and a hierarchical distribution and use structure has contributed to water reuse development in a safe, reliable and economical manner. This paper can be beneficial to water authorities and practitioners for long-term urban water management in other rapidly developing cities and regions that have encountered similar water-related problems.
•Oilfield PW sources, characteristics, and discharge regulations are reviewed.•Oilfield PW management including the state-of-the-art approaches are discussed.•Single treatment methods cannot meet all ...reuse and disposal requirements.•Design of an efficient hybrid system needs a structured and a risk-based approach.
Various stages of oil production and processing in petroleum industry produce an enormous amount of oilfield produced water (PW). Discharge of this huge amount of PW has an adverse impact on the surrounding environment as it contains different types of toxic and complex organic and inorganic compounds. For a long time, conventional treatment methods have been used to purify PW; however, these techniques could not meet the environmental regulations especially when the purpose is to reuse water. Therefore, more research efforts are required to select an effective technology that can mitigate the challenges through the best management strategy. In this study, the oilfield PW sources and characteristics, discharge regulations, treatment management, and recent advancements, challenges, and future needs in physical, chemical, thermal, biological, membrane, and hybrid treatment techniques are reviewed. Since the wastewater includes different recalcitrant pollutants, single technologies to date have not been successful enough in rendering it to a reusable form or meeting disposal requirements. Therefore, combined technologies might offer a promising process not only to meet the regulatory criteria but also to provide opportunities to use PW as a non-conventional water source. Furthermore, PW management needs a structured framework and a risk-based approach considering environmental, technical, and economic aspects to choose and design the most efficient strategy(ies).
Hypersaline brines are of growing environmental concern. While high-salinity desalination and zero liquid discharge (ZLD) are increasingly attractive treatment options, the high salt and scalant ...contents pose considerable technical difficulties to existing desalination techniques. In this review, we introduce sources of hypersaline brines, examine factors driving high-salinity desalination, and present the thermodynamic minimum energy of hypersaline desalination and ZLD, highlighting effects of mineral precipitation and imperfect salt rejection. We then critically examine prospects and challenges of 10 alternative technologies for hypersaline desalination: electrodialysis, osmotically-mediated reverse osmosis, forward osmosis, membrane distillation, humidification-dehumidification, solvent extraction desalination, supercritical water desalination, freeze desalination, clathrate hydrate desalination, and solar thermal desalination. Although electrodialysis and osmotically-mediated reverse osmosis show promise of having competitive energy efficiencies, these membrane-based techniques are still constrained by concentrate salinity limits. Recovery and reuse of heat will be vital for competitiveness of thermally-driven approaches. Technologies that intrinsically precipitate salts in bulk solution, namely solvent extraction desalination, supercritical water desalination, and humidification-dehumidification, can advantageously avoid mineral scaling. Due to the highly heterogeneous nature of hypersaline streams and the wide array of end-use goals, the high-salinity desalination market will ultimately be best served by a range of different technologies with distinctive capabilities.
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•Ten emerging technologies for high-salinity desalination are critically reviewed.•ED and OMRO show most promise in achieving high energy efficiencies.•SED, HDH, FO, MD, and STD can be driven by low-grade heat.•SED, SCWD, and HDH can potentially sidestep scaling issues.•High-salinity brines are diverse and will require different desalination approaches.
The separation properties of polyamide reverse osmosis and nanofiltration membranes, widely applied for desalination and water reuse, are constrained by the permeability-selectivity upper bound. ...Although thin-film nanocomposite (TFN) membranes incorporating nanomaterials exhibit enhanced water permeance, their rejection is only moderately improved or even impaired due to agglomeration of nanomaterials and formation of defects. A novel type of TFN membranes featuring an interlayer of nanomaterials (TFNi) has emerged in recent years. These novel TFNi membranes show extraordinary improvement in water flux (e.g., up to an order of magnitude enhancement) along with better selectivity. Such enhancements can be achieved by a wide selection of nanomaterials, ranging from nanoparticles, one-/two-dimensional materials, to interfacial coatings. The use of nanostructured interlayers not only improves the formation of polyamide rejection layers but also provides an optimized water transport path, which enables TFNi membranes to potentially overcome the longstanding trade-off between membrane permeability and selectivity. Furthermore, TFNi membranes can potentially enhance the removal of heavy metals and micropollutants, which is critical for many environmental applications. This review critically examines the recent developments of TFNi membranes and discusses the underlying mechanisms and design criteria. Their potential environmental applications are also highlighted.
•SWAT was modified for the multi-source water irrigation system with paddy rice.•A method was proposed to calculate return flow and its reuse amount based on the modified SWAT.•Two indicators were ...employed to analyze the spatial scale effect of reuse of return flow.•With the increase of spatial scale, the reuse rate of return flow increased and tended to stabilize.
Return flows in irrigation systems are often reused contributing to overall efficiency. To investigate the fate of return flows and the scale effects of reuses, the SWAT (Soil and Water Assessment Tool) model was modified to better represent the characteristics of paddy rice irrigation systems, which includes a simulation module for automatic multi-source irrigation (AMSIM). The modified SWAT model was used to simulate the hydrological processes in the Yangshudang (YSD) watershed of the Zhanghe Irrigation System (ZIS) in China. Furthermore, we proposed a method to calculate the amounts of return flows and the reused amount based on the output of the model. The sub-basins nesting method was used to divide the study area into six scales. We calculated the rainfall & irrigation water reuse rates (ηI+P) and the irrigation water reuse rates (ηI) at different scales and analyzed the changes of these two indicators over different scales. The results revealed that the modified SWAT model succeeded in simulating hydrological processes in a paddy rice irrigation system. ηI+P and ηI increased with the increase of scale. ηI+P was higher in the wet years and lower in the dry years, while ηI was higher in the dry years and lower in the wet years. The reason for increase of ηI+P and ηI as the scales increases were due to the fact that the return flows was repeatedly intercepted by downstream paddy fields, farm ponds, and drainage channels at larger scales, This reuse rates however reach the upper limit at a scale of 3500 ha, after which ηI+P and ηI no longer increase.
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