{"title":"How the Sponge City becomes a supplementary water supply infrastructure","authors":"Stephan Köster","doi":"10.1016/j.wen.2021.02.002","DOIUrl":"10.1016/j.wen.2021.02.002","url":null,"abstract":"<div><p>While in today’s Sponge Cities flood control works effectively, the sponge-based rainwater harvesting is associated with substantial challenges. In addition to water management, the pollution of collected stormwater counts as one of the major barriers for urban water augmentation. The aim of this communication is to outline how this constraint can be overcome and how the water service portfolio of the Sponge City can successfully undergo feasible expansion considering technical and also economic aspects. Innovative engineered solutions for a sponge-based rainwater harvesting are the key to an adaptive and flexible water supply infrastructure for Sponge Cities especially to preserve its manifold urban water and life quality services. The complementary water service, emerged from the Sponge City, can provide an imperative contribution to compensate the high capital investments and to cover the operation and maintenance costs. This enables a tremendous funding opportunities that can be invested for the preservation of the blue-green future city. Moreover, this would offer a feasible way of urban water service development over the negative impacts caused by climate change.</p></div>","PeriodicalId":101279,"journal":{"name":"Water-Energy Nexus","volume":"4 ","pages":"Pages 35-40"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.wen.2021.02.002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87524673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mandar S. Bhagat, Arvind K. Mungray, Alka A. Mungray
{"title":"Effect of sound waves and inclination of membrane on the performance of the osmotic microbial fuel cell","authors":"Mandar S. Bhagat, Arvind K. Mungray, Alka A. Mungray","doi":"10.1016/j.wen.2021.07.003","DOIUrl":"10.1016/j.wen.2021.07.003","url":null,"abstract":"<div><p>This study aimed to explore the effect of the sound wave and membrane inclination i.e., 45° and 90° (MI45 and MI90) on the performance of osmotic microbial fuel cell (OMFC). The vibrations were given by a sound intensity of 60–80 dB and 20–1000 Hz in an anode compartment for a period of 5–6 h per day. Membrane inclination was given to maximizing the effective surface area under a fixed plane without changing its volumetric capacity to enhance water flux. Membrane inclination increased the effective surface area up to 33.33%, therefore, water flux was increased by 10% by using 45° inclination. The OMFC produced maximum water flux, reverse salt flux and power density of 0.750 ± 0.02 and 0.666 ± 0.02 Lm<sup>-2</sup>h<sup>−1</sup>, 3.18 ± 0.02 and 3.10 ± 0.02 gm<sup>-2</sup>h<sup>−1</sup>, 35.22 ± 12 and 24.22 ± 08 mW.m<sup>−2</sup> for MI45 and MI90 respectively with the effect of sound. The chemical oxygen demand (COD) removal was found 66.85 ± 1% and 59.51 ± 1% with and without the effect of sound. Therefore, sound reduced the OMFC start-up time by 2–3 days based on open-circuit voltage data and also increased the anaerobic degradation by 6–9%. Overall, sound stimulates bacterial growth for the degradation of organic matter, and membrane inclination gives a more effective surface area for water flux.</p></div>","PeriodicalId":101279,"journal":{"name":"Water-Energy Nexus","volume":"4 ","pages":"Pages 113-122"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.wen.2021.07.003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91419229","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Comparative evaluation of wastewater and bioventing system for the treatment of acid mine drainage contaminated soils","authors":"Ifeanyi Michael Smarte Anekwe , Yusuf Makarfi Isa","doi":"10.1016/j.wen.2021.08.001","DOIUrl":"10.1016/j.wen.2021.08.001","url":null,"abstract":"<div><p>The increasing rate of soil pollution poses a prolific threat to the sustenance of the ecosystem. Acid mine drainage (AMD) is an environmental problem that has contributed immensely to soil pedogenesis and contamination associated with mining activities. Physical, chemical, and thermal methods of soil treatment have some rooms for improvement to meet remediation purposes. Contrary to other methods, bioremediation is a cost-effective and a sustainable biological approach that utilizes microorganisms for the remediation of a contaminated environment and does not recontaminate or further degrade the soil after application. This study aims to comparatively evaluate the application of wastewater and bioventing system for the the treatment of AMD contaminated soils. A microcosm containing 1 kg of contaminated soil was amended with wastewaters of varying (biostimulation (BSTa)) while bioventing treatment (BVTa) consists of the injection of atmospheric air through the vadose zone into bioreactors and amended with wastewater effluents. The treatment was conducted at ambient condition for 28 days. The result of the treatment recorded 28–67% and 58–70% metal (Mn, Fe, Al, Cu and Zn) removal efficiencies with 51% and 34% sulfate removal efficiencies for BSTa and BVTa treatments, respectively. However, attempts to improve the sulfate removal efficiencies through the injection of atmospheric air were not effective. This study showed that wastewater and bioventing can be effectively applied as a potential alternative for the treatment of AMD contaminated soils.</p></div>","PeriodicalId":101279,"journal":{"name":"Water-Energy Nexus","volume":"4 ","pages":"Pages 134-140"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.wen.2021.08.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81099578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jaydeep Jivani, Meka Srinivasarao, Anand P. Dhanwani
{"title":"Optimal methodology for water recycling and reusability of multiproduct batch plant","authors":"Jaydeep Jivani, Meka Srinivasarao, Anand P. Dhanwani","doi":"10.1016/j.wen.2021.10.001","DOIUrl":"10.1016/j.wen.2021.10.001","url":null,"abstract":"<div><p>Multiproduct batch plants are seriously affected by improper production schedules and inefficient wastewater handling. These batch process industries consume massive amounts of fresh water for process and multiple washings of process equipment. Primary objective of the present work is to minimize freshwater intake through proper handling and reuse of wastewater. This paper proposes an optimal methodology of wastewater recycle to address the environmental and economic issues. We explore the possibility of recycling reusable water before sending it to Effluent Treatment Plant (ETP) for treatment. We formulated a constraint, mixed integer non-linear programming (MINLP) optimization model, to simultaneously address environmental and economic issues for a multiproduct batch plant. The model applied to a process involving multiple washes and multiple storage tanks having pre-specified concentration limits. This model provides the amount of recyclable wash water, overall freshwater demand and effluent generation. The reported case study suggests that the freshwater reduction is in the range of 40–60%. We also performed dynamic simulations using the MATLAB-GAMS interface to monitor dynamic variation in the height of waste water in segregation tanks due to dynamic variation in wash water generation.</p></div>","PeriodicalId":101279,"journal":{"name":"Water-Energy Nexus","volume":"4 ","pages":"Pages 141-148"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2588912521000138/pdfft?md5=c64b56e9cab29ad648de9c83f8f7ac42&pid=1-s2.0-S2588912521000138-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77352923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Modelling the adsorption of iron and manganese by activated carbon from teak and shea charcoal for continuous low flow","authors":"Worlanyo Kwadjo Siabi , Emmanuel Degraft-Johnson Owusu-Ansah , Helen Michelle Korkor Essandoh , Nana Yaw Asiedu","doi":"10.1016/j.wen.2021.02.001","DOIUrl":"10.1016/j.wen.2021.02.001","url":null,"abstract":"<div><p>Nearly 6494 boreholes with iron (Fe) and manganese (Mn) concentrations above permissible limits of 0.3 mg/L and 0.4 mg/L respectively in Ghana have been abandoned because of ineffective water treatment solutions. Activated carbon prepared from teak (Tectona grandis) and shea (Vitellaria paradoxa) charcoal (ACM), of effective grain sizes 0.075–0.2 mm and 0.2–2.0 mm was found to achieve 92.5–100% Fe and Mn removal in batch tests. The experiments, which were repeated for natural groundwater with a low flow similar to boreholes simulated with handpumps and limited mechanized water systems achieved similar Fe and Mn adsorption levels. Data on Fe and Mn adsorption for varying ACM mass and grain sizes, using fixed columns in continuous flow tests were fitted to Adam-Bohart, Thomas and Yoon-Nelson adsorption models to generate data for improvement in water treatment designs. The objective of this modelling process is to develop a prediction mechanism for ACM mass and grain size needed for the design of Fe and Mn removal plants for groundwater with various characteristics. Adsorption constants obtained for Yoon-Nelson; 0.3095 and Adams-Bohart; 0.07335 at R<sup>2</sup> values of 0.9728 and 0.9841 respectively are appropriate for generating ACM mass needed, when the target contaminant is Fe and Mn</p></div>","PeriodicalId":101279,"journal":{"name":"Water-Energy Nexus","volume":"4 ","pages":"Pages 88-94"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.wen.2021.02.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85606240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Thillai Sivakumar Natarajan , Praveen Kumar Gopi , Kalithasan Natarajan , Hari C. Bajaj , Rajesh J. Tayade
{"title":"TiO2/graphene oxide nanocomposite with enhanced photocatalytic capacity for degradation of 2,4-dichlorophenoxyacetic acid herbicide","authors":"Thillai Sivakumar Natarajan , Praveen Kumar Gopi , Kalithasan Natarajan , Hari C. Bajaj , Rajesh J. Tayade","doi":"10.1016/j.wen.2021.07.001","DOIUrl":"10.1016/j.wen.2021.07.001","url":null,"abstract":"<div><p>The present study investigates the photocatalytic degradation of 2,4-Dichlorophenoxyacetic acid (2,4-D), a hazardous herbicide using TiO<sub>2</sub>/Graphene oxide nanocomposite photocatalysts. The nanocomposite photocatalysts were synthesized via solvothermal method by varying the weight percentage of graphene oxide. The nanocomposite photocatalysts were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer Emmet Teller (BET) adsorption isotherm, Fourier-transform infrared (FT-IR) and UV–visible-diffuse reflectance spectroscopy (UV–Vis-DRS) analysis. The XRD pattern of nanocomposite was found unaltered, whereas a significant change around 33–91% was observed in the surface area of nanocomposites as compared to the pristine TiO<sub>2</sub>. The UV–Vis DRS study showed a blue shift in the band edge of the composites around 21–29 nm. The complete photocatalytic degradation of 2,4-D was achieved using TiO<sub>2</sub>/GO<sub>7%</sub> catalyst within 4 h of reaction under UV-light irradiation. The photocatalytic activity of the synthesized nanocomposite photocatalysts was also compared with the standard Degussa P-25 TiO<sub>2</sub> photocatalyst. The order of photocatalytic activity of the synthesized photocatalysts were TiO<sub>2</sub>/GO<sub>7%</sub> > P25-TiO<sub>2</sub> > TiO<sub>2</sub>/GO<sub>5%</sub> > TiO<sub>2</sub>/GO<sub>2%</sub> > TiO<sub>2</sub>/GO<sub>1%</sub> > TiO<sub>2</sub>/GO<sub>10%</sub> > TiO<sub>2</sub>/GO<sub>0.5%</sub> > Pristine-TiO<sub>2</sub>. This study offers a better platform for the synthesis of new composite photocatalytic materials for environment abatement by the degradation of organic pollutants.</p></div>","PeriodicalId":101279,"journal":{"name":"Water-Energy Nexus","volume":"4 ","pages":"Pages 103-112"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.wen.2021.07.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82700528","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Long term relationship between food, energy and water inflation in South Africa","authors":"Saul Ngarava","doi":"10.1016/j.wen.2021.07.002","DOIUrl":"10.1016/j.wen.2021.07.002","url":null,"abstract":"<div><p>The food-energy-water (FEW) nexus provides leeway into the lateral transmission of price volatilities within the sectors. The problem is that any inflationary price tendencies in one of the FEW sectors will have direct and indirect effect on the others. The objective of the study was to ascertain the relationship between inflation in food, energy and water, and determine whether there were spill-overs, in South Africa. Monthly consumer price indices for food, energy and water for the period spanning from January, 2002 to December, 2020, were used. Parsimonious vector autoregressive (VAR) model was used in data analysis. The study found that prior to 2013, inflation rate was higher for food relative to water and energy, respectively. After 2017, water had a higher inflation rate relative to energy and food, respectively. Furthermore, energy inflation had positive impact on both water and food inflation, whilst water inflation also had positive impact on food inflation. The study concludes that there is a nexus in the lateral inflation between food, energy and water. Recommendations include building resilience within the nexus through decoupling food and other sectors from fossil fuel-derived energy. It is needed to strike a balance in biofuel and energy production policy to foster complementarities. Operational efficiencies within the sectors also need to be fostered.</p></div>","PeriodicalId":101279,"journal":{"name":"Water-Energy Nexus","volume":"4 ","pages":"Pages 123-133"},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.wen.2021.07.002","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77182819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Michael H. Kim , Chihhao Fan , Shu-Yuan Pan , Ingyu Lee , YuPo Lin , Hyunook Kim
{"title":"Kinetics of competitive cometabolism under aerobic conditions","authors":"Michael H. Kim , Chihhao Fan , Shu-Yuan Pan , Ingyu Lee , YuPo Lin , Hyunook Kim","doi":"10.1016/j.wen.2020.04.001","DOIUrl":"10.1016/j.wen.2020.04.001","url":null,"abstract":"<div><p>Commonly observed competitive substrate inhibition in cometabolism of organic contaminants is used as rate- and reducing-power-determining factors to develop a kinetic model of the competitive cometabolism. Analogous to the well-known theory of Leudeking-Piret kinetics where the product formation demands reducing power, cometabolism is modeled as a reducing power demanding process that also competes with microbial growth for the available reducing power from the degradation of energy-yielding primary substrate. The model further incorporates other growth-associated phenomena such as substrate inhibition and multiple growth/nongrowth substrate interactions that may occur during cometabolic transformation processes. The kinetic model is used successfully to predict a variety of degradation patterns of growth/nongrowth substrates, displayed by microbial cultures when exposed to different concentration ratios of growth to nongrowth substrate: a complete degradation of nongrowth substrates that coincides with the simultaneous depletion of a growth substrate and, in some other cases, an incomplete degradation of a nongrowth substrate following the complete depletion of a growth substrate. These distinct patterns of substrate degradation are attributed to intrinsic specificities of enzymes for cometabolism and lack of reducing power available from the growth substrate degradation. The efficacy of cometabolic capabilities of actively growing microbial cultures and pre-cultured resting cells is discussed in terms of reducing power available in such systems.</p></div>","PeriodicalId":101279,"journal":{"name":"Water-Energy Nexus","volume":"3 ","pages":"Pages 62-70"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.wen.2020.04.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72816638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Saif W. Mohammed Ali , Nasser Vahedi , Carlos Romero , Alparslan Oztekin
{"title":"An optimization for water requirement in natural gas combined cycle power plants equipped with once-through and hybrid cooling systems and carbon capture unit","authors":"Saif W. Mohammed Ali , Nasser Vahedi , Carlos Romero , Alparslan Oztekin","doi":"10.1016/j.wen.2020.08.001","DOIUrl":"10.1016/j.wen.2020.08.001","url":null,"abstract":"<div><p>A water-energy nexus analysis for a Natural Gas Combined Cycle power plant equipped with Post-Combustion Carbon Capture unit was studied. Once-through and hybrid indirect dry and wet cooling systems were considered. An optimization model was developed to minimize the water requirement in each of the cooling system. The model and numerical method were validated with previously reported experimental measurements. In once-through cooling system, the optimized mass flow rates were slightly less than the original operating condition. For hybrid cooling system, the effects of air to water ratio, humidity content, air wet bulb temperature, and the number of cycles of concentration on the water requirements were studied for a wide range of cooling load split factors. The difference in water requirement becomes insignificant when the cooling load exceeds 60%. It was shown that the increase in the number of cycles of concentrations reduces water losses within 5–6 cycles. It is recommended to consider dynamic control for the cooling system using the developed optimization algorithm to maintain optimum operating conditions. For the once-through cooling system, maintaining the least water withdrawal while protecting aquatic life is suggested. For hybrid cooling systems, keeping the split factor below 0.5 and optimizing water consumption and power penalty are recommended.</p></div>","PeriodicalId":101279,"journal":{"name":"Water-Energy Nexus","volume":"3 ","pages":"Pages 117-134"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.wen.2020.08.001","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86276520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yongjun Sun , Li Deng , Shu-Yuan Pan , Pen-Chi Chiang , Shailesh S. Sable , Kinjal J. Shah
{"title":"Integration of green and gray infrastructures for sponge city: Water and energy nexus","authors":"Yongjun Sun , Li Deng , Shu-Yuan Pan , Pen-Chi Chiang , Shailesh S. Sable , Kinjal J. Shah","doi":"10.1016/j.wen.2020.03.003","DOIUrl":"10.1016/j.wen.2020.03.003","url":null,"abstract":"<div><p>In the past few decades, urban flooding and water shortages caused by the rapid expansion of cities and the destruction of construction ecology have been harshly lost. The current ecological rainwater management system is based on the traditional gray infrastructure and cannot effectively solve the water problems of different scales. Sponge city, as an advanced rainwater management technology, plays a vital role in urban transformation and new construction. While building a sponge city, the gray infrastructure will be integrated to form a gray-green infrastructure integration, and the relationship between water and energy in the sponge city will be coordinated. This paper proposes the problems encountered in the transformation of the gray infrastructure of the sponge city to the green infrastructure and the measures to be taken. The integrated indicator system is used to comprehensively evaluate the integration of the gray-green facilities.</p></div>","PeriodicalId":101279,"journal":{"name":"Water-Energy Nexus","volume":"3 ","pages":"Pages 29-40"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.wen.2020.03.003","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90958105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}