Ruey-fang Yu - Academia.edu (original) (raw)

Papers by Ruey-fang Yu

Desalination and Water Treatment, Jun 1, 2011

Zenodo (CERN European Organization for Nuclear Research), Oct 1, 2015

Recovering resources from water purification sludge (WPS) have been gradually stipulated in envir... more Recovering resources from water purification sludge (WPS) have been gradually stipulated in environmental protection laws and regulations in many nations. Hence, reusing the WPS is becoming an important topic, and recovering alum from WPS is one of the many practical alternatives. Most previous research efforts have been conducted on studying the amphoteric characteristic of aluminum hydroxide for investigating the optimum pH range to dissolve the Al(III) species from WPS, but it has been lack of reaction kinetics or mechanisms related discussion. Therefore, in this investigation, water purification sludge (WPS) solution was broken by ultrasound to make particle size of reactants smaller, specific surface area larger. According to the reaction kinetics, these phenomena let the dissolved aluminum salt quantity increased and the reaction rate go faster.

Separation Science and Technology, Oct 1, 2007

Abstract Polyaluminum Silicate Chloride (PASiC) is a new water treatment coagulant. It contains s... more Abstract Polyaluminum Silicate Chloride (PASiC) is a new water treatment coagulant. It contains silica that can be hydrolyzed to produce SiO2 as coagulant aid. Hence, this coagulant consumes little alkalinity and is effective at low dosages. It is, therefore, ...

Environmental Engineering Science, Jun 1, 2010

International Journal of Mineral Processing, Sep 1, 2011

Three coagulants, polyaluminum chloride (PACl), aluminum sulfate (Alum) and cationic polyacrylami... more Three coagulants, polyaluminum chloride (PACl), aluminum sulfate (Alum) and cationic polyacrylamide (cPAM) are used in this investigation. A nephelometric turbidity monitoring system (NTMS), assembled from a nephelometric turbidimeter and a data acquisition unit, is used continuously to monitor online the turbidity data in a jar test. Both calculated standard deviation (SD) of the measured turbidity data and results of an

Colloids and Surfaces A: Physicochemical and Engineering Aspects, 2008

The coagulants of poly-aluminum-chloride (PAC), poly-aluminum-silicate-chloride (PASiC) and poly-... more The coagulants of poly-aluminum-chloride (PAC), poly-aluminum-silicate-chloride (PASiC) and poly-aluminum-ferric-silicate-chloride (PAF-SiC) were prepared in this study to evaluate their coagulation efficiencies and mechanisms in synthetic low-turbidity and low-alkalinity water containing organic matter. The experimental results show that PASiC and PAFSiC could remove the kaolin turbidity of the synthetic water with or without salicylic acid present. On the other hand, when the synthetic water contained both kaolin and humic acid in low turbidity and alkalinity, PAC would remove the turbidity but charge reversal of the colloidal particles would occur easily. Also, effective coagulation was limited to a very narrow dosage range. Conversely, the dosage range for the effective coagulation of both PASiC and PAFSiC was wider, although a higher dosage was required to remove the turbidity of wastewater. Therefore, the effective removal of turbidity was not only related to the kind of coagulant, but also to the types of organic matter. The coagulants PASiC and PAFSiC, particularly, proved themselves to be superior to the PAC in the treatment of low-turbidity water.

Journal of Hazardous Materials, Mar 1, 2012

The use of ultraviolet (UV) irradiation as a physical wastewater disinfection has increased in re... more The use of ultraviolet (UV) irradiation as a physical wastewater disinfection has increased in recent years, especially for wastewater reuse. The UV-TiO(2) can generate OH radicals, which is highly effective to inactivate microorganisms in wastewater disinfection. However, both UV and UV-TiO(2) disinfections create multiple physical, chemical, and bio-chemical phenomena that affect their germicidal efficiency. It is difficult to build a precise control model using existing mathematic models. This study applies artificial neural network (ANN) models to control UV and UV-TiO(2) disinfections. Experimental results indicate that the ANN models, which precisely generate relationships among multiple monitored parameters, total coliform counts in influent and effluent, and UV doses, can be used as control models for UV and UV-TiO(2) disinfections. A novel ANN control strategy is applied to control UV and UV-TiO(2) disinfection processes to meet three total coliform count limits for three wastewater reuse purposes. The proposed controlled strategy effectively controls UV and UV-TiO(2) disinfection, resulting in acceptable total coliform counts in effluent for the three wastewater reuse purposes. The required UV doses for UV-TiO(2) disinfection were lower than those for UV disinfection, resulting in energy saving and capacity reduction of 13.2-15.7%.

Environmental Engineering Science, Mar 1, 2012

Abstract A nephelometric turbidimeter monitoring system (NTMS) was utilized to measure the standa... more Abstract A nephelometric turbidimeter monitoring system (NTMS) was utilized to measure the standard deviation (SD) of turbidity of suspension solutions. Experimental results demonstrated that turbidity SD was consistent with the theory that underlay the “turbidity fluctuation technique.” The NTMS was also used at a full-scale drinking water treatment plant to continuously monitor turbidity in all flocculation tanks. Experimental results revealed that under coagulant dosages of 0.33, 0.92, 1.67, and 2.67 mg/L, turbidity SD was strongly correlated with floc diameter in the flocculation tank. Turbidity SD and floc diameter increased to their maximum values at a coagulant dosage of 0.92 mg/L. This result suggested that turbidity SD obtained by using an NTMS could be used to determine the operational important parameters of water treatment plants.

Environmental Engineering Science, May 1, 2003

This study evaluated the effect of enhanced coagulation on reservoir water using Al2(SO4)3, PACl,... more This study evaluated the effect of enhanced coagulation on reservoir water using Al2(SO4)3, PACl, FeCl3, and PFS as coagulants. The treatment efficiencies were evaluated by the removals of soluble organic mat-ter, turbidity, and bacteria. PFS was found to give better dissolved ...

Chemical Engineering Journal, Nov 1, 2014

Environmental Engineering Science, Apr 1, 2008

This study elucidates an ultrasonic vibration system to promote in alkalinity dosing, which is a ... more This study elucidates an ultrasonic vibration system to promote in alkalinity dosing, which is a new method for preparing polyaluminum chloride (PACl). The ultrasonic vibrating system breaks up the NaOH solution into a fine mist, which may be more evenly dispersed into ...

Water Science & Technology: Water Supply, Mar 1, 2003

Chlorination is the most practical way for the destruction of pathogenic and other harmful organi... more Chlorination is the most practical way for the destruction of pathogenic and other harmful organisms in water and wastewater treatment plants. However, highly erratic concentrations of ammonia is contained in most water and wastewater treatment plants, which will react to chlorine and seriously alter the required chlorine dosages in the control of chlorination. The conventional control of chlorine dosage is widely practical throughout the batch breakpoint chlorination test in the laboratory, which is not feasible for the requirement of real-time regulation of the chlorine demands. In this study, a simple automatic oxidation-reduction potential (ORP) titration system was developed for on-line determination of the chlorine demand. The experimental results showed that different decrease tendencies on ORP slope profiles were found to correlate to the ammonia concentrations in samples. In addition, the required chlorine demands were found to correlate to ammonia concentrations with a linear relationship. The ORP control strategy was, therefore, developed for on-line determination of the chlorine demands. Applying this ORP control strategy, the required chlorine demands were precisely predicted, and good disinfection efficiency was obtained in the wastewater chlorination experiments.

Advances in environmental research, 2016

Large amounts of aluminum hydroxide (Al(OH) 3) exist in water purification sludge (WPS) because o... more Large amounts of aluminum hydroxide (Al(OH) 3) exist in water purification sludge (WPS) because of the added aluminum coagulant in water treatment process. Notably, Al(OH) 3 is an amphoteric compound, can be dissolved in its basic condition using sodium hydroxide to form aluminate ions (Al(OH) 4-). However, in a process in which pH is increasing, the humid acid can be dissolved easily from WPS and will inhibit the recovery and reuse of the dissolved aluminate ions. This study attempts to fix this problem by a novel approach to separate Al(OH) 4 ions using nanofiltration (NF) technology. Sludge impurity in a alkaline solution is retained by the NF membrane, such that the process recovers Al(OH) 4 ions, and significantly decreases the organic matter or heavy metal impurities in the permeate solution. The Al(OH) 4 ion is an alkaline substance. Experimental results confirm that a recovered coagulant of Al(OH) 4 ion can effectively remove kaolin particles from slightly acidic synthetic raw water.

Japan Geoscience Union, Mar 14, 2019

Journal of Natural Gas Science and Engineering, Sep 1, 2016

Constructing new urban facilities requires precise study of the proper sitting in different parts... more Constructing new urban facilities requires precise study of the proper sitting in different parts of a city. The first point for the accurate allocation of urban facilities, is to select the optimal site regarding different conditions and it matters when it comes to important factors such as saving lives and safety of the people. Therefore, the optimal site selection of fire stations is essential because of the importance of the people who are in danger of fire and hazards. This research is applied in terms of purpose and in terms of method, is descriptive and in terms of data collection is a survey research. For this purpose, using the Analytic hierarchy process analysis in GIS, the results were analyzed by questionnaire. Using the overlapping method, the weighted criteria were combined and the optimal sites for the constructing of fire stations are specified. Results determined areas that have a higher priority and better conditions for the constructing of fire stations. The areas which have the most suitable conditions because of their proximity to the road, residential areas, the existence of health centers, as well as commercial centers, along with the existence of worn out structures, were in the first priority for the construction of new stations. However, other parts of the district are wellsuited for construction of new stations that are compatible and in fact confirm the current situation and the status.

Environmental Forensics, 2019

Groundwater quality in coastal area has been an issue of interest because of excessive groundwate... more Groundwater quality in coastal area has been an issue of interest because of excessive groundwater extraction for human use, for example, industrialization, irrigation, which can lead to saltwater intrusion. The study develops an integrated data analysis procedure based on multivariate statistics principal component analysis (PCA), hierarchical cluster analysis (HCA) and redundancy analysis (RDA), to determine the effects of key environmental conditions on the formulation of groundwater pollutants. This proposed method was demonstrated by analyzing groundwater quality monitoring data collected between 2011 and 2014 from four coastal industrial areas in Changhua county of Taiwan, namely Chuansing, Xianxi, Lukang and Fangyuan industrial parks. First, different environmental conditions in each industrial region were explored by PCA. The spatial hierarchy and spatial distribution of pollutant categories were then identified using HCA with the kriging method. Finally, the effect of environmental conditions on constitutive pollutants were identified with RDA. The three environmental patterns identified from the analytical results in Chuansing, Lukang and Xianxi were the salination factor (including conductivity and general hardness (GH)), water level and redox condition (including dissolved oxygen and oxidation-reduction potential). Fangyuan industrial park had only two patterns, namely salination (including conductivity and GH) and oxygen content (including DO and depth). The pollutant category indicated high concentrations of all pollutants in Chuansing and Fangyuan, and higher concentration of SO 4 2À , TDS, Cl À in Xianxi, and of NH 3-N, Mn, Fe and TOC in Lukang. According to RDA results, salination caused the high concentrations of NH 3 N, Cl À , TDS in Chuansing, and of Cl À , TDS and SO 4 2À in Xianxi and Lukang. Additionally, salination caused high concentrations of Fe in both Lukang and Fangyuan industrial parks in combination with those three pollutants. The redox condition was linked to high content of NO 3 À in Chuansing and Lukang, and of TOC in Xianxi. In Fangyuan industrial park, NO 3 À was also linked to high oxygen concentration. In summary, the combination of PCA, HCA and RDA enables the analysis of monitoring data to support policy decision-making.

International Journal of Environmental Science and Technology, Aug 12, 2014

Chemical coagulation is one of the most important processes for industrial wastewater treatment p... more Chemical coagulation is one of the most important processes for industrial wastewater treatment plants to remove the suspended solids (SS), which depend significantly on particle characteristics. A digital image analysis system was set up in this study for the on-line measurements of particle characteristics, including particle size distribution, equivalent diameter, total area, total volume, and the fractal dimension in the both coagulation and flocculation periods in chemical coagulation. Two real industrial wastewaters, textile wastewater and landfill leachate, were used for conducting the coagulation and flocculation processes with different polyaluminum chloride dosages in a batch reactor. The artificial neural network (ANN) models were used to construct the correlations between the monitoring data acquired and the SS removal efficiencies. The experimental results indicated that the ANN models were able to precisely predict the SS removal efficiencies and effluent SS concentration after the chemical coagulation, with the correlation coefficient (R 2) of 0.96-0.97 for real landfill leachate and R 2 of 0.93-0.97 for real textile wastewater, which provided significant benefits for the control of chemical coagulation.

[[abstract]]Coagulant dosing is one of the major operation costs in water treatment plant, and co... more [[abstract]]Coagulant dosing is one of the major operation costs in water treatment plant, and conventional control of this process for most plants is generally determined by the jar test. However, this method can only provide periodic information and is difficult to apply to automatic control. This paper presents the feasibility of applying artificial neural network (ANN) to automatically control the coagulant dosing in water treatment plant. Five on-line monitoring variables including turbidity (NTUin), pH (pHin) and conductivity (Conin) in raw water, effluent turbidity (NTUout) of settling tank, and alum dosage (Dos) were used to build the coagulant dosing prediction model. Three methods including regression model, time series model and ANN models were used to predict alum dosage. According to the result of this study, the regression model performed a poor prediction on coagulant dosage. Both time-series and ANN models performed precise prediction results of dosage. The ANN model with ahead coagulant dosage performed the best prediction of alum dosage with a R2 of 0.97 (RMS=0.016), very low average predicted error of 0.75 mg/L of alum were also found in the ANN model. Consequently, the application of ANN model to control the coagulant dosing is feasible in water treatment.[[notice]]補正完

Expert Systems with Applications, 2021

Abstract The adverse effects of dust storms such as air quality degradation, reduced visibility a... more Abstract The adverse effects of dust storms such as air quality degradation, reduced visibility and property damage are particularly prominent in estuarian regions. To reduce significant property and health risks posed by such river dust storms, an early-warning system is a useful tool that is urgently needed. In this case study of an area near an estuary, an artificial neural network with various sampling strategies is proposed for building an early-warning model. Records of past river episodes involving high concentrations of airborne particulate matter were collected and used for modeling. Among the three models developed, Model III which considers the characteristics of both environmental media and pollution sources was most accurate among other Models in predicting the severity of an estuarian dust events. The results revealed that the proposed forecasting model can efficiently predict high-pollution events and thus provide useful information enabling administrators and the public to implement preemptive disaster mitigative measures to avoid the negative health consequences of dust storms within estuarian regions.