Water Resources and Industry最新文献

Traditionally, industrial processes produce wastes that, even though often containing useful materials, are discarded, contributing to environmental pollution and depletion of natural resources. An example of such wastes are brines, flows of concentrated salts, produced in water treatment processes, which are now routinely discharged into receiving water bodies. Brines however can also be considered as flows of reusable materials which should be recovered, and the Zero Brine cooperation project aims to develop processes for that purpose. For a demineralized water production plant in the port of Rotterdam (the Netherlands), a closed water processing cycle was proposed to treat the large volume of spent Ion Exchange (IEX) regenerant brine which, apart from recovering demineralized water, is also intended to produce magnesium (Mg²⁺) and calcium (Ca²⁺) salts, with the highest purity possible, from the otherwise discharged brine. The process scheme includes nanofiltration (NF) for separating mono- and multivalent ions, followed by sequential chemical precipitation of Mg²⁺ and Ca²⁺ ions from the NF concentrate, and production of demineralized water by evaporation of the NF permeate. The concentrate of monovalent ions produced in the evaporator, essentially a concentrated sodium chloride solution, in its turn might be reused for IEX regeneration. Part of the supernatant of the sequential precipitation may be fed to the evaporator as well, but bleeding the other part of this supernatant is essential in order to maintain process stability, avoid accumulation of minor pollutants, and reduce scaling. In this study, various scenarios to operate the process were modeled, using PHREEQC and Excel. According to the simulation results, recovery of ≈97% of Mg²⁺ and Ca²⁺ is possible, the latter with a higher purity than the former. The main factors affecting the results are the concentration of carbonate present in the spent IEX regenerant, as well as characteristics of the NF membrane and the dosing of sodium hydroxide in the sequential precipitation steps. The results of the simulations were used for the design and operation of a pilot plant, comprising all mentioned process steps.

It is critical that the development of new technologies to solve environmental problems do not shift the burdens (impacts) to other mediums. Therefore, to ensure the optimum environmental design of water treatment and recovery systems, it is pertinent to apply life cycle assessment (LCA) at an early stage of development. Using LCA at an early developmental stage is known as prospective LCA and is particularly challenging due to the low data availability or quality. The aim of this study is to highlight the opportunities and challenges of using prospective LCA in the development of water treatment and recovery technologies. To do this we utilise two case studies from the EU Zero Brine project and apply LCA at two developmental stages. The treatment systems are specifically tailored for each case to treat the individual brine compositions and selectively recover its constituents. The first stage LCAs are based on laboratory experiments and engineering-based calculations, whilst the second stage assessments use improved input data from pilot plants and simulation. The paper compares the analyses of both stages, identifies key differences and discusses these disparities. In addition, it provides insights on the challenges of applying LCA for the design and development of wastewater treatment and recovery systems.

Bioelectrochemical systems (BESs) are considered as the potential approaches to remediate the environments contaminated by hydrocarbons. This review addresses the application of BESs particularly microbial fuel cells (MFCs) in degradation of petroleum hydrocarbons, including BTEXs, from soil, water, wastewater and sediments. Details on reactor design and critical issues are discussed. Aspects on electrodes, redox mediators and membranes are evaluated, including economic feasibility. The microbial community is considered in detail. It can be concluded, that comparing to classic configurations, single-chamber air-cathode reactors are more cost-effective. Secondly, systems based on small-scale units are recommended for future developments.

This work employs the data envelopment analysis technique to assess the water use efficiency of companies and the water reduction potential of industrial categories in industrial zones. Fifty-eight companies were selected from four industrial categories: wearing apparel (WA,18), fabricated metal (FM,12), rubber and plastic (RP,12), and other manufacturing (OM,12) based on six variables: monthly water usage, two types of effluent contaminant loadings, monthly production capacity, number of employees, and surface occupied by a company. The results indicate that significant numbers of companies are inefficient in water use, namely WA(28%), OM(42%), FM(43%), and RP(46%). Implementing technical measures to improve water use efficiency at these companies offers a varying water reduction potential per industrial category, namely in the order RP(25%) > FM(17%) ≫ WA(7%) > OM(4%). These results show that improving water efficiency by water use minimization is not the only ptential measure for improving the industrial zone's water metabolism towards self-sufficiency.

Water sterilisation requires the inactivation of waterborne pathogens, like E.coli, to such low levels that its use will not cause illness. Here, we examine a potential methodology for disinfecting water through the combined effect of hot expanding gases and shock waves from underwater explosions. Water pathogens located within the proximity of the explosive charge will be exposed to two different sterilisation conditions: firstly, the high-pressure shock wave moving within the fluid, and secondly, the expanding hot N₂, O_2, and CO₂ bubbles that are products of the explosion. To simulate the first case, we used a flyer-plate technique to understand the lower threshold for inactivation. We did this with a novel capsule design in a single-stage light gas-gun and observed 0.813 Logs of E.coli inactivation after subjecting an entire bacterial broth to a minimum pressure of 3.53 GPa thereby indicating a lower threshold for shock pressure-induced inactivation. For the second case, we show that hot gas bubbles from different explosive gaseous products at 150°C in a bubble column established the minimum gas temperature thresholds required to successfully inactivate E.coli. This work shows that any benefit of using explosives to sterilise water will principally come from the release of hot gaseous bubbles rather than the effect of the shock. This new approach could be used in conflict areas or remote locations with no access to standard sterilisation technologies or power.

In this study, metallic iron nanoparticles (Fe NPs) and metallic copper nanoparticles (Cu NPs) were prepared, characterized, and used in the removal of methyl orange (MO) dye. The experiments investigated first the UV–Vis spectra of dye molecules in three types of solvents (water, water-ethanol, and water-dimethyl sulfoxide). The removal of MO was then conducted under various experimental conditions to investigate the effects of solvent type, nanoparticles dosage, salinity of the solutions, temperature, and shaking time. The highest extent of MO removal was achieved in water solutions. Under all experimental conditions, Fe NPs showed higher efficiency than Cu NPs in MO removal. Moreover, heterogeneous Fenton process led to smaller MO removal when compared with the direct use of the nanoparticles, for both water and water-ethanol solutions. From a kinetic perspective, the dye removal process was much faster in water than in water-ethanol mixtures, and the data followed pseudo-second order rate equation.

This paper presents a hybrid advanced oxidation process (AOP) based on sonocavitational activation of persulfate (PS) for degradation of 1,4-dioxane during wastewater treatment. Application of sono-cavitation effectively convert PS to radical species demonstrating synergistic effect by increasing the reaction rate and reducing the required energy for activation. It is economically feasible and deployed alternative to the direct thermal activation method. A single and two-stage injection of PS were compared to eliminate self-scavenging effects related to excess of oxidant in system. A GC-MS analysis was used to determine the degradation products of dioxane and to propose the degradation mechanism. The studies revealed that the degradation was significantly enhanced by the addition of PS at molar ratio of oxidant to pollutant 4 with a two-stage injection. Under optimal conditions at US density of 105 W/cm², dioxane with an initial concentration of 100 mg/L was completely degraded in 120 min.

Water sector planning and policy making in arid and semi-arid regions are challenging because many drivers and decision criteria require consideration. In this study, a multi-period mixed-integer linear programming model was developed to integrate and economically evaluate water management options for water supply in arid regions. The applicability of the proposed approach was demonstrated through a case study in the Emirate of Abu Dhabi (EAD), United Arab Emirates. The model was programmed in general algebraic modeling system (GAMS) and solved using the Cplex solver. The model determined the optimal economic and environmental costs, capacity expansion of treatment plants and water transmission systems, and other environmental aspects including the carbon footprint and brine discharge. Results show that the capacity contribution of reverse osmosis for desalination is expected to increase from 5.1% in 2021 to 18.1% in 2050. Based on the model's results for the case study, it was concluded that even with moderate consideration of environmental aspects, desalination plants in the EAD need a major technology transformation from thermal desalination to reverse osmosis The proposed model is proved to be effective for integrated water resources management and infrastructure planning in the EAD, and has the potential for effective application in other arid or semi-arid countries.