Beijing Waterworks Group Co.

Beijing, China

Beijing Waterworks Group Co.

Beijing, China
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Xie J.,Xi'an University of Architecture and Technology | Xie J.,CAS Research Center for Eco Environmental Sciences | Chen Y.,Beijing Waterworks Group Co. | Bi Z.,China Institute of Metrology | And 2 more authors.
Chinese Journal of Environmental Engineering | Year: 2014

The water turbidity and temperature of a reservoir in Beijing are low in winter, and this results in excessive residual aluminum in finished water during this period of time. To solve this problem, the performances of polyaluminium chloride (PAC) and new coagulants consisting of PAC and ferric chloride (FeCl3) were studied by jar tests. The results show that the best coagulation performance was achieved at a molar ratio of 1/5 for Fe/Al, with the lowest residual aluminum and the highest organic matter removal efficiencies. At this ratio, at the dosage of PAC 0.03 mmol/L, the lowest residual aluminum was at a very low concentration of 0.0063 mg/L. The turbidity removal efficiencies of iron and aluminum composite coagulants were lower than those of PAC at the same dosage. When the dosage of the composite coagulant with a Fe/Al molar ratio of 1/5 was at 0.06 mmol/L, the treated water turbidity could be decreased to 0.4 NTU. In addition, the effective dosage cover range, thus easy for coagulant control in treatment plants. It is also suitable for treating source waters with normal water temperature with a mild alkalinity. Pilot plant tests with a capacity of 5 m3/h demonstrated the effectiveness of the Fe-Al composite coagulant after long time and continuous run.

Zhou Z.,Beijing University of Technology | Yang Y.,Beijing University of Technology | Li X.,Beijing University of Technology | Wang W.,Beijing University of Technology | And 3 more authors.
Separation and Purification Technology | Year: 2014

This research innovatively investigated the coagulation performance of recycling pre-sonicated condensate drinking water treatment sludge under different ultrasound (US) conditions (ultrasonic time of 5, 10, 15, 20 and 30 min and US frequencies of 25, 40, 125 and 160 kHz) for low-turbidity surface water treatment. The formation, breakage and re-growth of re-coagulated flocs generated by recycling processes were examined using photometric dispersion analyzer to explore flocs growth properties, flocs strength and re-aggregation potential. The morphological analysis was further conducted to study the structural properties of the broken flocs to elucidate the reversibility/ irreversibility of re-growth process. The results indicated that 25 or 40 kHz within 5 min sonication was more favorable for turbidity removal, while 125 or 160 kHz with 10 or 15 min for organics removal. The recoverability of broken flocs was irreversible for the recycling processes regardless of US frequencies. Additionally, the flocs formed preliminarily exposed to 25 or 40 kHz were stronger and more resistant to breakage, and the recoverability was more irreversible. Furthermore, the flocs formed at 25 or 40 kHz were larger and more irregular with more porous and ramose structure. The average size obtained from morphological analysis could also strongly demonstrate the irreversibility of recovery process. © 2013 Elsevier B.V. All rights reserved.

Yu J.,CAS Research Center for Eco Environmental Sciences | An W.,CAS Research Center for Eco Environmental Sciences | Cao N.,Beijing Waterworks Group Co. | Yang M.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Journal of Environmental Sciences (China) | Year: 2014

Taste and odor (T/O) in drinking water often cause consumer complaints and are thus regulated in many countries. However, people in different regions may exhibit different sensitivities toward T/O. This study proposed a method to determine the regional drinking water odorant regulation goals (ORGs) based on the odor sensitivity distribution of the local population. The distribution of odor sensitivity to 2-methylisoborneol (2-MIB) by the local population in Beijing, China was revealed by using a normal distribution function/model to describe the odor complaint response to a 2-MIB episode in 2005, and a 2-MIB concentration of 12.9. ng/L and FPA (flavor profile analysis) intensity of 2.5 was found to be the critical point to cause odor complaints. Thus the Beijing ORG for 2-MIB was determined to be 12.9. ng/L. Based on the assumption that the local FPA panel can represent the local population in terms of sensitivity to odor, and that the critical FPA intensity causing odor complaints was 2.5, this study tried to determine the ORGs for seven other cities of China by performing FPA tests using an FPA panel from the corresponding city. ORG values between 12.9 and 31.6. ng/L were determined, showing that a unified ORG may not be suitable for drinking water odor regulations. This study presents a novel approach for setting drinking water odor regulations. © 2014.

Zhang J.,CAS Research Center for Eco Environmental Sciences | Yang M.,CAS Research Center for Eco Environmental Sciences | Guo Z.,CAS Research Center for Eco Environmental Sciences | Yu J.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Ozone: Science and Engineering | Year: 2011

Diatoms were shown to be responsible for clogging the sand filtration tanks in the waterworks of Beijing treating reservoir source water. The effect of pre-ozonation on the performance of the sand filter was investigated using a continuous-flow (200 L h-1) pilot experimental system. At the optimum ozone dose of 1.0 mg L-1, the filter run time was prolonged 2.7-2.8-fold, the number of 2-5 μm diameter particles decreased from 353-829 ml-1 to 53-269 ml-1 and the turbidity in the filtrate decreased from >0.2 NTU to < 0.1 NTU. Laboratory tests showed that ozone was able to break the cells of the diatoms, including Fragilaria sp., Diatoma sp. and Navicula sp., into smaller particles, and the optimum ozone dose was also 1.0 mg L-1. Decomposition of algae is likely to be the main reason for the significantly improved performance of filtration. © 2011 International Ozone Association.

Chen Y.,CAS Research Center for Eco Environmental Sciences | Chen Y.,Beijing Waterworks Group Co. | Xiao F.,CAS Research Center for Eco Environmental Sciences | Liu Y.,Beijing Waterworks Group Co. | And 4 more authors.
Frontiers of Environmental Science and Engineering | Year: 2014

The continuous variations of dissolved oxygen (DO), manganese (Mn), pH, and their effect on manganese removal by different water treatment processes are investigated. The results show that the declined DO concentration and pH value in the bottom of reservoir results in the increasing release of Mn from sediment to source water. Manganese concentration increased from 0.1 to 0.4 mg·L-1 under the condition that DO concentration decreased from 12.0 to 2.0 mg·L-1 in raw water. The different water treatment processes exhibited different efficiency on manganese removal. The processes with recycling of the suspended sludge, low elevation velocity in settling tank and slow filter rate, will benefit the manganese removal. During a high release of manganese in raw water, traditional coagulation-sedimentation and filtration could not completely remove Mn, although granular activated carbon filtration (GAC) had been applied. At that case, preoxidation with chlorine or potassium permanganate (KMnO4) was necessary to address the high manganese concentration. © 2014 Higher Education Press and Springer-Verlag Berlin Heidelberg.

Bu Q.,CAS Research Center for Eco Environmental Sciences | Wang D.,CAS Research Center for Eco Environmental Sciences | Wang Z.,CAS Research Center for Eco Environmental Sciences | Gu J.,Beijing Waterworks Group Co.
Frontiers of Environmental Science and Technology | Year: 2013

The Danjiangkou reservoir was selected to provide the source water for the middle routes of the South to North Water Transfer Project, which has provoked many environmental concerns. To date, investigations of water contamination of the source water of the Danjiangkou reservoir with organic micro-pollutants have been limited. This study was conducted to identify and rank organic contaminants that pose risks in the Danjiangkou reservoir. To this end, the Chemical Hazard Evaluation and Management Strategies (CHEMS-1) approach was adapted to integrate the deconvolution technology of qualitative identifying contaminants for site-specific environmental matrices. The samples were screened for the presence of 1093 contaminants using deconvolution technologies and the hazard values of the identified contaminants were calculated using the adapted CHEMS-1 approach according to their hazardous properties and occurrence in source water. The results showed that 46 contaminants from 1093 targets were present in Danjiangkou water, 23 of which appeared at frequencies higher than 50%, and 15 of which were identified as priorities. Over half (53%) of the highranked contaminants were polycyclic aromatic hydrocarbons (PAHs), with chrysene ranked highest on the list. Health risk assessment of the top-ranked PAHs was conducted and revealed that cancer risks of PAHs detected in the source water of Danjiangkou to different populations ranged from 10-7 to 10-6, indicating a low cancer risk to consumers. The results of this study indicated that the adapted CHEMS-1 approach was feasible for site-specific screening of organic contaminants to identify and rank potential priority pollutants. © 2013 Higher Education Press and Springer-Verlag Berlin Heidelberg.

Yu J.,CAS Research Center for Eco Environmental Sciences | An W.,CAS Research Center for Eco Environmental Sciences | Yang M.,CAS Research Center for Eco Environmental Sciences | Gu J.,Beijing Waterworks Group Co. | And 2 more authors.
Clean - Soil, Air, Water | Year: 2014

Taste and odor have been a recurring problem for many water utilities. This paper established an optimized strategy to cope with 2-methylisoborneol (2-MIB) by combining the determination of the control goal according to native population sensitivity and the prediction of the optimum powdered activated carbon (PAC) dose using the homogeneous surface diffusion model (HSDM). The results showed that the population in Beijing was very sensitive to 2-MIB. Based on flavor profile analysis result conducted by a local panel, the odor threshold concentration (OTC) for Beijing population was determined to be 7.1 ng/L. This value was further certified by the significant odor complaint evaluation using a logit model and set as the control goal for the water treatment plant. According to the OTC level, a 2-MIB removal prediction curve was then constructed for estimating the optimum PAC dose based on the HSDM. This study can provide a practical technical solution for the control of seasonable odor problems in waterworks. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Wu J.,Beijing Waterworks Group Co. | Wu J.,Technical University of Denmark | Lind M.,Technical University of Denmark | Zhang X.,Technical University of Denmark | And 2 more authors.
Computer Aided Chemical Engineering | Year: 2015

Qualitative modeling paradigm offers process systems engineering a potential for developing effective tools for handling issues related to Process Safety. A qualitative functional modeling environment can accommodate different levels of abstraction for capturing knowledge associated with the process system functionalities as required for the intended safety applications. To provide the scientific rigor and facilitate the acceptance of qualitative modelling, this contribution focuses on developing a scientifically based validation method for functional models. The Multilevel Flow Modeling (MFM) methodology is adopted in the paper as a formalized qualitative functional modeling methodology for dynamic process systems. A functional model validation procedure is proposed to assess whether the intended modeling purpose indeed represents a relevant proposal and whether the model represents the system behavior sufficiently well. With the reasoning capability provided by the MFM syntax and semantics, the validation procedure is illustrated on a three-phase separator system of an MFM model. The MFM model reasoning results successfully compares against analysis results from API RP. 14-C. © 2015 Elsevier B.V.

Wang Y.L.,Beijing Forestry University | Yan W.L.,Beijing Forestry University | Qian X.,Beijing Forestry University | Sheng Y.Q.,Beijing Forestry University | Chen Y.J.,Beijing Waterworks Group Co.
Journal of Water Process Engineering | Year: 2015

Three types of polyacrylamide (PAM) flocculants of cationic PAM WD4960, non-ionic PAM M351, and anionic PAM WDA110 had different performances on the Ferric hydroxide gel (FHG) dewaterability and that M351 was the best one. The optimum dosages of these PAMs did not completely depend on the FHG total suspended solid (TSS) content of 0.2-1.5. g/L. The amount of PAM absorbed on the FHG surface linearly increased with an increase in its dosage, and saturation adsorption did not occur at the tested PAM dosages. The rise in PAM dosage can increase the size of conditioned FHG flocs/aggregates, while can decrease their compactness. The conditioned FHG aggregates at the optimum M351 dosage exhibited a moderate size, the smoothest surface, and the least compact structure among the three types of PAM. Conditioning the raw FHG with the cationic PAM of WD4960 increased its positive charge and decreased its hydrophilicity and specific surface area (S). However, M351 or WDA110 conditioning only increased the negative surface charge and hydrophilicity and decreased the S value of the conditioned FHG. The osmotic pressure variations indicated that, as a hydrogel, the optimum WD4960-conditioned FHG had stronger potential to absorb water from outside than the M351 or WDA110-conditioned FHG. Compared with that in the raw FHG, the free water content (FWC) reduction in the M351- or WD4960-conditioned FHG contributed entirely to the increase in bound water content (BWC) and the water release outside the hydrogel. © 2015 Elsevier Ltd.

Yan W.L.,Beijing Forestry University | Yan W.L.,Beijing Waterworks Group Co. | Wang Y.L.,Beijing Forestry University | Wang Y.L.,Beijing Waterworks Group Co. | Chen Y.J.,Beijing Waterworks Group Co.
Water Research | Year: 2013

Three types of polyacrylamide (PAM) flocculants with different charges (cationic PAM WD4960, nonionic PAM M351, and anionic PAM WDA110) were used for water treatment residuals (WTRs) conditioning, and the physicochemical, morphological and structural characteristics of raw and conditioned WTRs were investigated. Rheological methods were employed to analyze the internal structural transition between the raw and conditioned WTRs under a typical dosage of WD4960. Results showed that when the raw WTRs were conditioned with the polymers, the optimum dosage of WD4960 was 4.82g/kg total suspended solid (TSS) while that of both M351 and WDA110 was 7.24g/kg TSS. The residual PAM content in the supernatant of the WTR matrix conditioned at the optimum WD4960 dosage was 5.59mg/L, which is the least among the supernatants obtained with the three types of PAM. Furthermore, the visible fulvic acid (FA) in the supernatant disappeared and the intensity of the ultraviolet FA decreased. The average diameter of irregularly shaped aggregates in the WTR suspensions increased from 35.73μm to several hundred micrometers with increasing PAM dosage. The size of WTR aggregates conditioned at the optimum WD4960 dosage was much larger than that of aggregates obtained at the optimum M351 or WDA110 dosages. Two-dimensional fractal dimension (D2) values presented an increasing trend with increasing PAM dosage. D2 values of the conditioned WTR aggregates were 1.87, 1.76, and 1.83 at optimum WD4960, M351, and WDA110 dosages, respectively. The cationic PAM (CPAM) WD4960 thus appears to be a more ideal conditioner for WTRs. Consistent relationships were observed among the capillary suction time (CST), average particle size, and D2 values of the conditioned WTR aggregates at the optimum WD4960 dosage. Mass fractal dimensions (Df) indicated that both the raw and WD4960-conditioned WTRs behave like weak-link flocs/aggregates. Df values (log G'-log TSS) of the WTR aggregates before and after conditioning with the optimum WD4960 dosage were 2.79 and 2.81, respectively. Although the transition from an alum/ferric hydrogel to a cross-linked gel occurred during the WD4960-conditioning process, only a small amount of the alum/ferric hydrogel was destroyed, and the conditioned WTR aggregates showed a gel-like matrix in which residual alum-ferric hydrogels were embedded in cross-linked WD4960 molecules. © 2013 Elsevier Ltd.

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