AbstractThe Noor III solar tower of the Ouarzazate Solar Power Station in Morocco is a very slender structure sensitive to wind excitations. Hence, tuned mass dampers (TMDs) were employed to reduce ...its wind-induced response. Finite-element modeling and wind-tunnel test results were employed to design the parameters of the TMD system. Four 10-t TMDs with eddy-current damping (EC-TMD) were selected for implementation (via a customized steel frame) at the top of the solar tower (i.e., inside the receiver). The effectiveness of the designed TMDs in controlling the tower was numerically studied under free vibration and forced vibration. Then, considering design and modeling errors and the possible need for on-site adjustments of EC-TMD parameters, pendulum-type EC-TMDs were fabricated. Dynamic properties of the tower were identified based on field measurements. With the installation and adjustment of the four designed EC-TMDs, the damping ratio of the Noor III solar tower was enhanced from 0.72% to 3.78%. Field measurements of tower vibrations under strong winds with/without participation of the EC-TMDs showed that significant mitigation of wind-induced response was effectively achieved by the TMDs with eddy-current damping. In addition, the on-site acceleration measured on the prototype tower was compared with the acceleration obtained for the scale model in a wind tunnel to highlight the significant Reynolds number effects on the prediction of the wind-induced response of the solar tower structure.
Extracellular polymeric substances (EPSs) are key biological substances, which largely determine properties of sludge flocs, including hydrophobicity, adhesion, flocculation, settling and dewatering ...properties, and therefore significantly affect membrane fouling in membrane bioreactors (MBRs). Much progress has been achieved in understanding of EPSs and their interrelations with membrane fouling due to a large number of systematic papers published in the last three decades. In this paper, the fundamentals of EPSs including definitions, compositions and properties are summarized. The interrelations of EPSs with other foulants in MBRs are clarified. Roles of EPSs in membrane fouling mechanisms in MBRs are critically assessed. Furthermore, factors affecting EPSs production and characteristics are summarized, and based on which, EPSs control towards membrane fouling mitigation in MBRs are comprehensively discussed. Finally, future research perspectives regarding EPSs and membrane fouling are proposed.
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•Fundamentals of EPSs including composition and properties are summarized.•Roles of EPSs in membrane fouling in MBRs are addressed.•Factors affecting EPSs in MBRs are summarized.•Strategies of EPSs control towards fouling mitigation are discussed.•Research directions regarding fouling caused by EPSs are identified.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Membrane bioreactor (MBR) technology has been extensively employed for various industrial wastewater treatments due to its distinct advantages over conventional technologies. To provide present state ...and development trends of MBR technology used for industrial wastewater treatments, the authors reviewed and analyzed more than 300 scientific publications. They present an overview of the most recent development of MBR technology for treatment of industrial wastewaters (e.g., food processing, pulp and paper, textile, tannery, landfill leachate, pharmaceutical, oily and petrochemical wastewaters). Moreover, they discuss the operational characteristics, fouling characteristics, fouling control strategies, and costs of MBRs in industrial wastewater treatments. Based on the present information on MBR technology, the authors discuss further research aspects of MBRs in industrial wastewater treatments.
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
•Air-scoured washing has been proposed and tested for scale detachment in the electrochemical water softening process.•Effective scale detachment was achieved.•High softening efficiency and low ...energy consumption could be obtained stably.
Treatment of recirculate cooling water using electrochemical method has obtained great attentions in recent years due to its environmental friendliness and easy operation. In order to ensure persistent hardness removal efficiency, periodical cleaning of cathode surface is essential. However, currently available electrode cleaning techniques are either inefficient or laborious. In this work, air-scoured washing was proposed to replace conventional scale detachment methods in the electrochemical water softening process. Mirror stainless steel was found to be the most suitable cathode material because it could enhance scale detachment significantly. Effective water softening and scale detachment were achieved. The precipitation rate was as high as 25.5–34.3g/h/m2. After the air-scoured washing scale detachment, the cathode could resume their ability to soften. The energy consumption and the total removal efficiency were 17.6–22.3kWh/kg CaCO3 and 12.2–15.2%, respectively. Repetitive experimental results indicated the electrochemical water softening process using air-scoured washing could run steadily without any performance decay detected after repetitive operation.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Based on the daily measured data of meteorological stations and the reanalysis data of forecast factors, a statistical downscaling and a decision tree model were used to predict the future change of ...extreme climate index in the Yellow River Delta region of China, and the two models' performance were compared. The results showed that the decision tree was more accurate in predicting extreme climate at regional scale than those of the statistical downscaling model.
