scholarly journals Treatment Technologies for Cooling Water Blowdown: A Critical Review

2021 ◽  
Vol 14 (1) ◽  
pp. 376
Author(s):  
Mariam Soliman ◽  
Fadwa Eljack ◽  
Monzure-Khoda Kazi ◽  
Fares Almomani ◽  
Elalim Ahmed ◽  
...  

Cooling water blowdown (CWBD) generated from different industries and district cooling facilities contains high concentrations of various chemicals (e.g., scale and corrosion inhibitors) and pollutants. These contaminants in CWBD streams deem them unsuitable for discharge into surface water and some wastewater treatment plants. The pollutants present in CWBD, their sources, and the corresponding impacts on the ecosystem are discussed. The international and regional (Gulf states) policies and regulations related to contaminated water discharge standards into water bodies are examined. This paper presents a comprehensive review of the existing and emerging water treatment technologies for the treatment of CWBD. The study presents a comparison between the membrane (membrane distillation (MD), reverse osmosis (RO), nanofiltration (NF), and vibratory shear enhanced membrane process (VSEP)) and nonmembrane-based (electrocoagulation (EC), ballasted sand flocculation (BSF), and electrodialysis (ED)) technologies on the basis of performance, cost, and limitations, along with other factors. Results from the literature revealed that EC and VSEP technologies generate high treatment performance (EC~99.54% reduction in terms of silica ions) compared to other processes (membrane UF with reduction of 65% of colloidal silica). However, the high energy demand of these processes (EC~0.18–3.05 kWh/m3 and VSEP~2.1 kWh/m3) limit their large-scale applications unless connected with renewable sources of energy.

2005 ◽  
Vol 187 (17) ◽  
pp. 5937-5945 ◽  
Author(s):  
Ana Segura ◽  
Patricia Godoy ◽  
Pieter van Dillewijn ◽  
Ana Hurtado ◽  
Nuria Arroyo ◽  
...  

ABSTRACT Pseudomonas putida DOT-T1E is tolerant to toluene and other toxic hydrocarbons through extrusion of the toxic compounds from the cell by means of three efflux pumps, TtgABC, TtgDEF, and TtgGHI. To identify other cellular factors that allow the growth of P. putida DOT-T1E in the presence of high concentrations of toluene, we performed two-dimensional gel analyses of proteins extracted from cultures grown on glucose in the presence and in the absence of the organic solvent. From a total of 531 spots, 134 proteins were observed to be toluene specific. In the absence of toluene, 525 spots were clearly separated and 117 proteins were only present in this condition. Moreover, 35 proteins were induced by at least twofold in the presence of toluene whereas 26 were repressed by at least twofold under these conditions. We reasoned that proteins that were highly induced could play a role in toluene tolerance. These proteins, identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry, were classified into four categories: 1, proteins involved in the catabolism of toluene; 2, proteins involved in the channeling of metabolic intermediates to the Krebs cycle and activation of purine biosynthesis; 3, proteins involved in sugar transport; 4, stress-related proteins. The set of proteins in groups 2 and 3 suggests that the high energy demand required for solvent tolerance is achieved via activation of cell metabolism. The role of chaperones that facilitate the proper folding of newly synthesized proteins under toluene stress conditions was analyzed in further detail. Knockout mutants revealed that CspA, XenA, and Tuf-1 play a role in solvent tolerance in Pseudomonas, although this role is probably not specific to toluene, as indicated by the fact that all mutants grew more slowly than the wild type without toluene.


2020 ◽  
Vol 1 (1) ◽  
pp. 33-47
Author(s):  
Tran Viet Dung

AbstractVietnam has experienced an economic growth accompanied by increasing energy demand and inadequate supplies. Like most developing countries, the increased inefficient use of energy in Vietnam leads to increased greenhouse gas emissions and high energy costs for consumers. Also, the traditional sources of energy are not sufficient to satisfy the demand of the economic sectors.With the negative impact of climate change on water resources and the depletion of coal, oil and gas reserves, Vietnam must diversify and integrate other forms of renewable energies into its energy mix. The efficient use of renewable energy resources can boost economic development. Thus, the policies for endorsing renewable energies and energy efficiency are playing a vital role in ensuring the sustainable development for Vietnam’s future. This paper examines the legal and policy framework influencing the deployment of renewable energies and energy efficiency in Vietnam. The paper also attempts to identify major barriers to a large scale deployment of renewable energies and energy efficiency technologies and offers some possible solutions.


2015 ◽  
Vol 713-715 ◽  
pp. 118-121
Author(s):  
You Wei Chen

This paper carries on the simulation and optimization of hydraulic system, which focuses on the high energy consumption problem of large-scale blow molding machines. According to the characteristics of long work period and great fluctuation of flow demand, the paper designs the oil supplying system that can match the actuators’ hydraulic energy demand, introduces the working process of each component in the system, and analyzes the key technology of hydraulic system as well. The design and research avoids the shortcomings such as more components, complex debugging, discontinuous control and unstable operation, substantially reduces the installed capacity of variable pump and driving motor, and in the meantime, solves the impact problem of actuators effectively, which can make hydraulic system high efficiency, energy saving and run steadily.


2021 ◽  
Author(s):  
Karin van der Wiel ◽  
Laurens Stoop ◽  
Bas van Zuijlen ◽  
Russel Blackport ◽  
Mechteld van den Broek ◽  
...  

<p>To mitigate climate change a renewable energy transition is needed. Existing power systems will need to be re-designed to balance variable renewable energy production with variable energy demand. I will describe the meteorological sensitivity of a highly-renewable European energy system based on large ensemble simulations from two global climate models. From 2×2000 years of simulated weather conditions, we calculated daily wind and solar energy yields and energy demand and selected events of high societal impact: extreme high energy shortfall (residual load, i.e. demand minus renewable production). High energy shortfall days are characterized by large-scale high pressure systems over central Europe, with lower than normal wind speeds and below normal temperatures, driving up energy demands. The events typically occur mid-winter, locked to the coldest months of the year. Near-stationary high pressure situations occur that cause long lasting periods of high energy shortfall. A spatial redistribution of wind turbines and solar panels cannot prevent these high-impact events, options to import renewable energy from remote locations during these events are therefore limited. Projected changes due to climate change are substantially smaller than interannual variability. Future power systems with large penetration of variable renewable energy must be designed with these events in mind.</p>


2021 ◽  
Vol 2042 (1) ◽  
pp. 012019
Author(s):  
G Peronato ◽  
R Boghetti ◽  
J H Kämpf

Abstract Aggregated building energy demand is a useful indicator for urban energy planning. It can be used by planners and decision-makers to identify clusters of high energy demand in a given urban area and efficiently plan, for example, district heating networks. Various data sources exist at the pan-European level describing land use and built areas. Combined with statistical data, such maps have been used in previous research for estimating building energy performance aggregated at the hectare level, using engineering assumptions. In this paper, we show that large-scale land-use maps alone can be used for predicting annual building energy demand with an accuracy comparable to the one of previous engineering models. We hence present a preliminary method based on Convolutional Neural Networks at different spatial resolutions. The resulting model was trained and tested in an area of about 170 km1 in Geneva (Switzerland) using a local annual heating demand dataset comprising 16239 buildings. On a 300-m aggregation tile, the obtained mean error (14.3%) is significantly reduced compared to the one of a simple linear model (37.2%). Using solely land-use data, we also achieve similar results for a 100-m tile as those of an engineering model from the literature.


Molecules ◽  
2019 ◽  
Vol 24 (20) ◽  
pp. 3702 ◽  
Author(s):  
Ana S. Mestre ◽  
Ana P. Carvalho

The presence of pharmaceutical compounds in the environment is a reality that calls for more efficient water treatment technologies. Photocatalysis is a powerful technology available but the high energy costs associated with the use of UV irradiation hinder its large scale implementation. More sustainable and cheaper photocatalytic processes can be achieved by improving the sunlight harvesting and the synthesis of semiconductor/carbon composites has proved to be a promising strategy. Carbamazepine, diclofenac, and sulfamethoxazole were selected as target pharmaceuticals due to their recalcitrant behavior during conventional wastewater treatment and persistence in the environment, as properly reviewed. The literature data on the photocatalytic removal of carbamazepine, diclofenac, and sulfamethoxazole by semiconductor/carbon materials was critically revised to highlight the role of the carbon in the enhanced semiconductor performance under solar irradiation. Generally it was demonstrated that carbon materials induce red-shift absorption and they contribute to more effective charge separation, thus improving the composite photoactivity. Carbon was added as a dopant (C-doping) or as support or doping materials (i.e., nanoporous carbons, carbon nanotubes (CNTs), graphene, and derived materials, carbon quantum dots (CQDs), and biochars) and in the large majority of the cases, TiO2 was the semiconductor tested. The specific role of carbon materials is dependent on their properties but even the more amorphous forms, like nanoporous carbons or biochars, allow to prepare composites with improved properties compared to the bare semiconductor. The self-photocatalytic activity of the carbon materials was also reported and should be further explored. The removal and mineralization rates, as well as degradation pathways and toxicity of the treated solutions were also critically analyzed.


2012 ◽  
Vol 573-574 ◽  
pp. 120-125 ◽  
Author(s):  
Shuang Jiang Lü ◽  
Qi Jun Gao ◽  
Xiao Long Lü

Based on the high energy consumption of membrane distillation (MD) process and the excessive cooling water consumption issues, a new type of vacuum multiple-effect membrane distillation (MEMD) process was designed. The process set up a special multiple-effect evaporation zone for the first time where heat exchange and MD happened at the same time. The experiment studied the effects of the membrane area in main evaporation zone, feed fluid flow of the lumen side of membrane module and module length of multiple-effect evaporation zone on MEMD process. The equivalent flux of the system can reach the maximal value (34.8 kg•m-2•h-1) and the additional cooling water consumption is only 30.8% of traditional VMD process when the feed inlet temperature of the module and the membrane area in the main evaporation zone are 345 K and 0.10 m2, feed fluid flow is 4.0 L•h-1, and the module length is 868 mm of multiple-effect evaporation zone. The MEMD process has a wonderful industrial application prospect.


2010 ◽  
Vol 10 (3) ◽  
pp. 416-427 ◽  
Author(s):  
R. Kempton ◽  
D. Maccioni ◽  
S. M. Mrayed ◽  
G. Leslie

Three alternative approaches to desalinating seawater were evaluated with respect to their thermodynamic efficiencies and greenhouse-gas emissions. The technologies considered were multistage flash distillation (MSF), reverse osmosis (RO), and membrane distillation (MD). The analysis was based on published stream data from large-scale operational MSF and RO facilities and experimental-scale data for the MD process. RO was found to be the most exergy-efficient (30.1%) followed by MD (14.27%) and MSF (7.73%). RO and MD required less power consumption to produce water (3.29 kWh/m3 and 5.9 kWh/m3, respectively) compared to MSF which had a much higher energy demand (16.7 kWh/m3). Similar results were obtained when comparing equivalent carbon dioxide emissions from each process; MD and RO accounted for 5.22 and 2.91 kg CO2eq/m3, respectively, whereas MSF generated three to four times that amount. The results indicate that MD has potential as a commercially viable technique for seawater desalination provided a source of waste heat is available. This study provides an overview of the use of thermodynamic efficiency analysis to evaluate desalination processes and provides insight into where energy may be saved with developed desalination processes and areas of research for emerging desalination techniques.


Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 6056 ◽  
Author(s):  
Adam Masłoń ◽  
Joanna Czarnota ◽  
Aleksandra Szaja ◽  
Joanna Szulżyk-Cieplak ◽  
Grzegorz Łagód

The improvement of energy efficiency ensuring high nutrients removal is a great concern for many wastewater treatment plants (WWTPs). The energy balance of a WWTP can be improved through the application of highly efficient digestion or its intensification, e.g., through the introduction of the co-substrates with relatively high energy potential to the sewage sludge (SS). In the present study, the overview of the energetic aspect of the Polish WWTPs was presented. The evaluation of energy consumption at individual stages of wastewater treatment along with the possibilities of its increasing was performed. Additionally, the influence of co-digestion process implementation on the energy efficiency of a selected WWTP in Poland was investigated. The evaluation was carried out for a WWTP located in Iława. Both energetic and treatment efficiency were analyzed. The energy balance evaluation of this WWTP was also performed. The obtained results indicated that the WWTP in Iława produced on average 2.54 GWh per year (7.63 GWh of electricity in total) as a result of the co-digestion of sewage sludge with poultry processing waste. A single cubic meter of co-substrates fed to the digesters yielded an average of 25.6 ± 4.3 Nm3 of biogas (between 18.3 and 32.2 Nm3/m3). This enabled covering the energy demand of the plant to a very high degree, ranging from 93.0% to 99.8% (98.2% on average). Importantly, in the presence of the co-substrate, the removal efficiency of organic compounds was enhanced from 64% (mono-digestion) to 69–70%.


2015 ◽  
Vol 713-715 ◽  
pp. 764-767
Author(s):  
Lin Qiu

Through the analysis of molding process of large-scale plastic hollow containers, this paper carries on the simulation and optimization of hydraulic system, which focuses on the high energy consumption problem of large-scale blow molding machine. According to the characteristics of long work period and great fluctuation of flow demand, the paper designs the oil supplying system that can match the actuators’ hydraulic energy demand, introduces the working process of each component in the system, and analyzes the key technology of hydraulic system as well. The design and research avoids the shortcomings such as more components, complex debugging, discontinuous control and unstable operation, substantially reduces the installed capacity of variable pump and driving motor, and in the meantime, solves the impact problem of actuators effectively, which can make hydraulic system high efficiency, energy saving and run steadily.


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