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Applying chemical sedimentation process in drinking water treatment plant to address the emergent arsenic

Pengfei LIN,Xiaojian ZHANG,Hongwei YANG,Yong LI,Chao CHEN

《环境科学与工程前沿(英文)》 2015年 第9卷 第1期   页码 50-57 doi: 10.1007/s11783-014-0733-2

摘要: Arsenic (As) spills occurred more frequently and sometimes polluted water sources in recent years in China. It is as urgent need to develop emergency treatment technologies to address the arsenic threat for large-scale water treatment plants. In response, we developed a chemical sedimentation technology to remove arsenic contaminants for water treatment plants. Bench-scale experiments were conducted to investigate the efficiency of arsenic removal and the influencing factors of the chemical sedimentation treatment process. The influencing factors included the choice and dosage of coagulants, the valence of arsenic and pH value of solution. The As(V) contaminants can be almost completely removed by ferric or alum coagulants. The As(III) contaminants are more recalcitrant to chemical sedimentation, 75% for ferric coagulant and 40% for alum coagulant. The quantitative results of arsenic removal load by different ferric or alum coagulants were presented to help determine the parameters for arsenic treatment technology. The dominant mechanism for arsenic removal is static combination, or adsorption of negative arsenic species onto positive ferric hydroxide or alum hydroxide flocs. The efficiency of this treatment technology has also been demonstrated by a real production test in one water treatment plant with arsenic-rich source water and one emergency response. This technology was verified to be quick to set-up, easy to operate and highly efficient even for high concentration of arsenic.

关键词: Arsenic spill     chemical sedimentation     coagulation     drinking water     emergency treatment    

Classification of contaminants and treatability evaluation of domestic wastewater

WANG Xiaochang, JIN Pengkang, ZHAO Hongmei, MENG Lingba

《环境科学与工程前沿(英文)》 2007年 第1卷 第1期   页码 57-62 doi: 10.1007/s11783-007-0011-7

摘要: Long-term sampling and analysis were conducted in a domestic wastewater treatment plant for the investigation on the characteristics of the representative contaminants in raw sewage such as SS, COD, BOD5, TP, and TN. All these constituents were classified into dissolved and suspended groups by using a 0.45-µm membrane filter, and the concentration of each constituent in each group was analyzed. As a result, almost 100% of the SS was found to be suspended matter, as well as about 65% of COD, 60% of BOD, 50% of P, and 20% of N. All these could be easily removed by sedimentation or coagulation/sedimentation. A treatability evaluation diagram was proposed for a rational selection of wastewater treatment process in accordance with raw water quality.

关键词: Long-term sampling     selection     accordance     wastewater treatment     coagulation/sedimentation    

Preparation and sedimentation behavior of conductive polymeric nanoparticles

WANG Jixiao, LIU Rui, ZHANG Xiaoyan, ZHOU Zhibin, WANG Zhi, WANG Shichang

《化学科学与工程前沿(英文)》 2008年 第2卷 第3期   页码 231-235 doi: 10.1007/s11705-008-0055-7

摘要: A facile route to prepare FeO/polypyrrole (PPY) core-shell magnetic nanoparticles was developed. FeO nanoparticles were first prepared by a chemical co-precipitation method, and then FeO/PPY core-shell magnetic composite nanoparticles were prepared by in-situ polymerization of pyrrole in the presence of FeO nanoparticles. The obtained nanoparticles were characterized by scanning electronic microscopy (SEM), transmission electronic microscopy (TEM) and laser particle size analyzer. The images indicate that the size of FeO particles is about 10 nanometers, and the particles are completely covered by PPY. The FeO/PPY core-shell magnetic composite nanoparticles are about 100 nanometers and there are several FeO particles in one composite nanoparticle. The yield of the composite nanoparticles was about 50%. The sedimentation behavior of FeO/PPY core-shell magnetic nanoparticles in electrolyte and soluble polymer solutions was characterized. The experimental results indicate that the sedimentation of particles can be controlled by adjusting electrolyte concentration, solvable polymers and by applying a foreign field. This result is useful in preparing gradient materials and improving the stability of suspensions.

Aortic aneurysm and chronic disseminated intravascular coagulation: a retrospective study of 235 patients

null

《医学前沿(英文)》 2017年 第11卷 第1期   页码 62-67 doi: 10.1007/s11684-017-0498-7

摘要:

Chronic disseminated intravascular coagulation (DIC) is a rare but devastating complication of aortic aneurysm (AA). This study investigated the clinical manifestations, laboratory findings, and treatment of patients with AA-associated chronic DIC (AA-DIC) and explored the mechanisms, duration, and therapeutic response of AA-DIC. We retrospectively reviewed the medical records of 235 AA patients admitted at the Peking Union Medical College Hospital between September 2009 and January 2015. The patients were classified as those with DIC (AA-DIC) and those without DIC (non-DIC). The AA-DIC group showed a significantly higher proportion of female patients and a significantly longer AA disease course than the non-DIC group did. The AA-DIC patients presented mural thrombi, dissecting aneurysms, a family history of AA, and diabetes significantly more frequently than the non-DIC patients did. Furthermore, multiple regression analyses revealed that sex, mural thrombus, aneurysm type, diabetes, and stent surgery are possible independent risk factors for AA-DIC patients. Fifty-two (22.1%) patients presented AA-DIC. Among these patients, 43 had non-typical DIC and 9 had typical DIC; the mortality rate of the latter was 22.2%. The mean age of the patients with typical DIC was significantly higher than of that of patients with non-typical DIC. The non-typical DIC patients also presented abnormal coagulation disorders of varying degrees. Furthermore, heparin or low-molecular-weight heparin improved the clinical symptoms and laboratory parameters in patients with AA and typical DIC. Thus, chronic DIC should be considered in patients with AA.

关键词: aortic aneurysm     disseminated intravascular coagulation     anticoagulation therapy    

Enhanced cross-flow filtration with flat-sheet ceramic membranes by titanium-based coagulation for membrane

《环境科学与工程前沿(英文)》 2022年 第16卷 第8期 doi: 10.1007/s11783-022-1531-x

摘要:

• Ceramic membrane filtration showed high performance for surface water treatment.

关键词: Ceramic membrane     Coagulation     Polytitanium chloride     Membrane fouling    

Performance evaluation on the pollution control against wet weather overflow based on on-site coagulation

Zongqun Chen, Wei Jin, Hailong Yin, Mengqi Han, Zuxin Xu

《环境科学与工程前沿(英文)》 2021年 第15卷 第6期 doi: 10.1007/s11783-021-1400-z

摘要: Abstract • A way for overflow control based on on-site coagulation/flocculation was proposed. • Coagulant and flocculant dose were optimized based on pollutant removal performance. • Settling time of 5 min is enough in a proper transmission distance. • Fast removal of particulate pollutants could be achieved under varied flow. The pollution caused by wet weather overflow in urban drainage systems is a main factor causing blackening an odorization of urban rivers. The conventional overflow treatment based on coagulation/flocculation in terminal drainage systems requires relatively large space and long retention time demand that makes it not applicable in crowded urban drainage systems or under heavy rains. On-site coagulation/flocculation in terminal drainage pipes was proposed in this study which was aimed to transfer the coagulation/flocculation process to the inside of pipes at the terminal drainage system to save space and reduce the retention time of the coagulation/flocculation process. The optimized dose of chemicals was studied first which was 80 mg/L of coagulant and 0.8 mg/L of flocculant. Settling for only 5 min can remove most of the pollutants at 406.5 m of transmission distance. In addition, the relation of wet weather overflow rate and concentration of pollution load on the on-site coagulation/flocculation process was investigated, which indicated that high removal of pollutant was gained at a large range of flow velocity and pollutant concentration. Finally, the study confirmed electric neutralization, bridging, and net capture as the major mechanisms in this process, and further optimization was proposed. The proposed process can reduce much turbidity, chemical oxygen demand, and total phosphorous, but hardly remove soluble ammonia and organics. This work provides scientific guidance to address wet weather overflow in terminal drainage pipes.

关键词: Wet weather overflow     On-site coagulation/flocculation     Fast removal of particulate pollutants    

Surface water treatment benefits from the presence of algae: Influence of algae on the coagulation behavior

Yanxia Zhao, Huiqing Lian, Chang Tian, Haibo Li, Weiying Xu, Sherub Phuntsho, Kaimin Shih

《环境科学与工程前沿(英文)》 2021年 第15卷 第4期 doi: 10.1007/s11783-020-1350-x

摘要: Abstract • Emerging titanium coagulation was high-efficient for algae-laden water treatment. • Polytitanium coagulation was capable for both algae and organic matter removal. • Surface water purification was improved by around 30% due to algae inclusion. • Algae functioned as flocculant aid to assist polytitanium coagulation. • Algae could enhance charge neutralization capability of polytitanium coagulant. Titanium-based coagulation has proved to be effective for algae-laden micro-polluted water purification processes. However, the influence of algae inclusion in surface water treatment by titanium coagulation is barely reported. This study reports the influence of both Microcystis aeruginosa and Microcystis wesenbergii in surface water during polytitanium coagulation. Jar tests were performed to evaluate coagulation performance using both algae-free (controlled) and algae-laden water samples, and floc properties were studied using a laser diffraction particle size analyzer for online monitoring. Results show that polytitanium coagulation can be highly effective in algae separation, removing up to 98% from surface water. Additionally, the presence of algae enhanced organic matter removal by up to 30% compared to controlled water containing only organic matter. Polytitanium coagulation achieved significant removal of fluorescent organic materials and organic matter with a wide range of molecular weight distribution (693–4945 Da) even in the presence of algae species in surface water. The presence of algae cells and/or algal organic matter is likely to function as an additional coagulant or flocculation aid, assisting polytitanium coagulation through adsorption and bridging effects. Although the dominant coagulation mechanisms with polytitanium coagulant were influenced by the coagulant dosage and initial solution pH, algae species in surface water could enhance the charge neutralization capability of the polytitanium coagulant. Algae-rich flocs were also more prone to breakage with strength factors approximately 10% lower than those of algae-free flocs. Loose structure of the flocs will require careful handling of the flocs during coagulation-sedimentation-filtration processes.

关键词: Coagulation     Polytitanium chloride     Coagulation behaviour     Algae     Floc property    

Fouling mechanisms in the early stage of an enhanced coagulation-ultrafiltration process

Haiqing CHANG,Baicang LIU,Wanshen LUO,Guibai LI

《环境科学与工程前沿(英文)》 2015年 第9卷 第1期   页码 73-83 doi: 10.1007/s11783-014-0692-7

摘要: We investigated the fouling performances of ultrafiltration (UF) membrane for treating in-line coagulated water in an enhanced coagulation-UF hybrid process. Then we analyzed the fouling mechanisms in the early stage of UF using mathematical models and microscopy observation methods. Finally, we discussed the impact of aeration on membrane fouling in this paper. The results showed that a two-stage of trans-membrane pressure (TMP) profile during the operation of enhanced coagulation-UF membrane was observed, and the relationship between permeability and operation time fitted well with a logarithmic curve. Membrane pores blocking and cake filtration were confirmed as main membrane fouling mechanisms using the mathematical models. The two stages of membrane fouling mechanisms were further deduced, namely, the membrane pore narrowing followed by the formation of cake layer. Membrane autopsy analysis using scanning electron microscopy (SEM) images of the membrane surface sampled from different filtration cycles also confirmed the mechanisms of pores blocking and cake filtration. Moreover, according to the variations of the permeability and membrane fouling resistance, aeration was able to mitigate and control the membrane fouling to a certain extent, but the optimization of aeration conditions still needs to be studied.

关键词: coagulation-UF     trans-membrane pressure (TMP)     permeability     membrane fouling resistance     scanning electron microscopy (SEM)    

Clinical study on the related markers of blood coagulation in the patients with ANFH after SARS

WU Lianhua, GAO Chunjin, WANG Guozhong, YANG Lin, HOU Xiaomin, GE Huan, XIA Chengqing, QI Man

《医学前沿(英文)》 2007年 第1卷 第4期   页码 410-412 doi: 10.1007/s11684-007-0080-9

摘要: The aim of this research was to investigate the blood coagulation function in the patients with avascular necrosis of the femoral head (ANFH) after severe acute respiratory syndrome (SARS). The expression of CD31, CD61, CD62p, CD63 and PAC-1 on platelet membrane was measured respectively by flowcytometry, and the plasma prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT) and fibrinogen (Fbg) were measured by blood clotting instrument in 26 patients with ANFH after SARS and in 17 healthy adults. The expression of CD31, CD61, CD 62p, CD63 and PAC-1 on platelet membrane in 26 patients was all lower than that in 17 healthy subjects (<0.01). The levels of PT, APTT, TT and Fbg in 26 patients were all normal. There is no significant difference (>0.05) in those markers between patients and 17 healthy adults. The blood may not be in hypercoagulable state in patients with ANFH after SARS.

关键词: significant difference     partial thromboplastin     coagulation function     femoral     healthy    

Effects of water quality on the coagulation performances of humic acids irradiated with UV light

Wendong WANG,Qinghai FAN,Zixia QIAO,Qin YANG,Yabo WANG,Xiaochang WANG

《环境科学与工程前沿(英文)》 2015年 第9卷 第1期   页码 147-154 doi: 10.1007/s11783-014-0749-7

摘要: The presence of humic acid in drinking water treatment has received significant attention in recent years because of its adverse effects on the removal of many pollutants in coagulation. In this paper, the effects of water quality including pH, turbidity, alkalinity, and hardness on the removal of humic acid were investigated in a UV light hybridized coagulation process. Our results suggested that UV light radiation could effectively improve the removal rate of humic acid in coagulation under both neutral and basic conditions, and the variations of the selected water quality parameters had little adverse effect on the function of UV light. After UV light radiation, the removal rate of the nitro-humic acid (NHA) increased from 20% to 60% in coagulation, and increased further to 75% and 85% for the raw waters with 10.0 NTU kaolin and 100 mg·L hardness, respectively. In addition to NHA, the removal rates of the humic acid extracted from peat coal (PHA) and the humic acid provided by Japan metals and chemicals company (JHA) in coagulation were also improved, both in the range of 80%–90% after undergoing UV light radiation. By changing the radiation location from prior to coagulation to the flocculation process, similar experimental results were obtained. The formation of positive charged sites after UV light radiation was considered to be the primary factor that led to an enhanced removal of the humic acid in coagulation.

关键词: coagulation     drinking water     humic acid     UV light radiation     water quality    

Influence of coagulation bath on morphology of cellulose membranes prepared by NMMO method

LU Yangcheng, WU Yingxin

《化学科学与工程前沿(英文)》 2008年 第2卷 第2期   页码 204-208 doi: 10.1007/s11705-008-0027-y

摘要: To control the morphology of cellulose membranes used for separation, they were prepared by the NMMO method using water, methanol, ethanol and their binary solution as coagulation baths. Morphologies of the surface and cross section of dry membranes were observed. The pore structure parameters of wet membranes were determined. By comparison, the process and mechanism of pore formation in dry membranes were suggested, and the relativity of cellulose crystal size to average pore diameter in wet membranes and their influences were discussed. The results show that the morphology of dry membranes is clearly varied with coagulation baths, while the porosity of wet membranes is almost constant. Porous structures can appear in the compact region of dry membranes due to swelling from water. These pores have a virtual effect on the average pore diameter of wet membranes. By changing the composition of coagulation baths, the microstructure of cellulose membranes in a dry or wet environment can be adjusted separately.

关键词: comparison     NMMO     constant     diameter     process    

Development of combined coagulation-hydrolysis acidification-dynamic membrane bioreactor system for treatment

Xue Shen, Lei Lu, Baoyu Gao, Xing Xu, Qinyan Yue

《环境科学与工程前沿(英文)》 2019年 第13卷 第1期 doi: 10.1007/s11783-019-1093-8

摘要:

• We created a combined system for treating oilfield polymer-flooding wastewater.

• The system was composed of coagulation, hydrolysis acidification and DMBR.

• Coagulant integrated with demulsifier dominated the removal of crude oil.

• The DMBR proceed efficiently without serious membrane fouling.

关键词: Coagulation     Hydrolysis acidification     Dynamic membrane bioreactor     Polymer flooding    

Optimization and modeling of coagulation-flocculation to remove algae and organic matter from surface

Ziming Zhao, Wenjun Sun, Madhumita B. Ray, Ajay K Ray, Tianyin Huang, Jiabin Chen

《环境科学与工程前沿(英文)》 2019年 第13卷 第5期 doi: 10.1007/s11783-019-1159-7

摘要: Charge neutralization and sweep flocculation were the major mechanisms. Effect of process parameters was investigated. Optimal coagulation conditions were studied by response surface methodology. ANN models presented more robust and accurate prediction than RSM. Seasonal algal blooms of Lake Yangcheng highlight the necessity to develop an effective and optimal water treatment process to enhance the removal of algae and dissolved organic matter (DOM). In the present study, the coagulation performance for the removal of algae, turbidity, dissolved organic carbon (DOC) and ultraviolet absorbance at 254 nm (UV254) was investigated systematically by central composite design (CCD) using response surface methodology (RSM). The regression models were developed to illustrate the relationships between coagulation performance and experimental variables. Analysis of variance (ANOVA) was performed to test the significance of the response surface models. It can be concluded that the major mechanisms of coagulation to remove algae and DOM were charge neutralization and sweep flocculation at a pH range of 4.66–6.34. The optimal coagulation conditions with coagulant dosage of 7.57 mg Al/L, pH of 5.42 and initial algal cell density of 3.83 × 106 cell/mL led to removal of 96.76%, 97.64%, 40.23% and 30.12% in term of cell density, turbidity, DOC and UV254 absorbance, respectively, which were in good agreement with the validation experimental results. A comparison between the modeling results derived through both ANOVA and artificial neural networks (ANN) based on experimental data showed a high correlation coefficient, which indicated that the models were significant and fitted well with experimental results. The results proposed a valuable reference for the treatment of algae-laden surface water in practical application by the optimal coagulation-flocculation process.

关键词: Algae     Coagulation-flocculation     Response surface methodology     Artificial neural networks    

Prediction of hydro-suction dredging depth using data-driven methods

《结构与土木工程前沿(英文)》 2021年 第15卷 第3期   页码 652-664 doi: 10.1007/s11709-021-0719-7

摘要: In this study, data-driven methods (DDMs) including different kinds of group method of data handling (GMDH) hybrid models with particle swarm optimization (PSO) and Henry gas solubility optimization (HGSO) methods, and simple equations methods were applied to simulate the maximum hydro-suction dredging depth (hs). Sixty-seven experiments were conducted under different hydraulic conditions to measure the hs. Also, 33 data samples from three previous studies were used. The model input variables consisted of pipeline diameter (d), the distance between the pipe inlet and sediment level (Z), the velocity of flow passing through the pipeline (u0), the water head (H), and the medium size of particles (D50). Data-driven simulation results indicated that the HGSO algorithm accurately trains the GMDH methods better than the PSO algorithm, whereas the PSO algorithm trained simple simulation equations more precisely. Among all used DDMs, the integrative GMDH-HGSO algorithm provided the highest accuracy (RMSE = 7.086 mm). The results also showed that the integrative GMDHs enhance the accuracy of polynomial GMDHs by ~14.65% (based on the RMSE).

关键词: sedimentation     water resources     dam engineering     machine learning     heuristic    

Alteration of heat shock protein 20 expression in preeclamptic patients and its effect in vascular and coagulation

Fanfan Li, Mengzhou He, Meitao Yang, Yao Fan, Yun Chen, Xi Xia, Yin Xie, Dongrui Deng

《医学前沿(英文)》 2018年 第12卷 第5期   页码 542-549 doi: 10.1007/s11684-017-0576-x

摘要:

Preeclampsia (PE) is a pregnancy-specific, multi-system disorder and the leading cause of maternal and perinatal morbidity and mortality in obstetrics worldwide. Excessive vasoconstriction and dysregulated coagulation function are closely associated with PE. Heat shock protein 20 (HSP20) is ubiquitously expressed under normal physiological conditions and has important roles in vascular dilatation and suppression of platelet aggregation. However, the role of HSP20 in the pathogenesis of PE remains unclear. In this study, we collected chorionic plate resistance arteries (CPAs) and serum from 118 healthy pregnant women and 80 women with PE and detected the levels of HSP20 and its phosphorylated form. Both HSP20 and phosphorylated HSP20 were downregulated in CPAs from women with PE. Comparison of the vasodilative ability of CPAs from the two groups showed impaired relaxation responses to acetyl choline in preeclamptic vessels. In addition to the reduced HSP20 in serum from women with PE, the platelet distribution width and mean platelet volume were also decreased, and the activated partial thromboplastin time and thromboplastin time were elevated. With regard to the vital roles of HSP20 in mediating vasorelaxation and coagulation function, the decreased HSP20 might contribute to the pathogenesis of PE.

关键词: preeclampsia     heat shock protein 20     vascular relaxation     coagulation-fibrinolytic system    

标题 作者 时间 类型 操作

Applying chemical sedimentation process in drinking water treatment plant to address the emergent arsenic

Pengfei LIN,Xiaojian ZHANG,Hongwei YANG,Yong LI,Chao CHEN

期刊论文

Classification of contaminants and treatability evaluation of domestic wastewater

WANG Xiaochang, JIN Pengkang, ZHAO Hongmei, MENG Lingba

期刊论文

Preparation and sedimentation behavior of conductive polymeric nanoparticles

WANG Jixiao, LIU Rui, ZHANG Xiaoyan, ZHOU Zhibin, WANG Zhi, WANG Shichang

期刊论文

Aortic aneurysm and chronic disseminated intravascular coagulation: a retrospective study of 235 patients

null

期刊论文

Enhanced cross-flow filtration with flat-sheet ceramic membranes by titanium-based coagulation for membrane

期刊论文

Performance evaluation on the pollution control against wet weather overflow based on on-site coagulation

Zongqun Chen, Wei Jin, Hailong Yin, Mengqi Han, Zuxin Xu

期刊论文

Surface water treatment benefits from the presence of algae: Influence of algae on the coagulation behavior

Yanxia Zhao, Huiqing Lian, Chang Tian, Haibo Li, Weiying Xu, Sherub Phuntsho, Kaimin Shih

期刊论文

Fouling mechanisms in the early stage of an enhanced coagulation-ultrafiltration process

Haiqing CHANG,Baicang LIU,Wanshen LUO,Guibai LI

期刊论文

Clinical study on the related markers of blood coagulation in the patients with ANFH after SARS

WU Lianhua, GAO Chunjin, WANG Guozhong, YANG Lin, HOU Xiaomin, GE Huan, XIA Chengqing, QI Man

期刊论文

Effects of water quality on the coagulation performances of humic acids irradiated with UV light

Wendong WANG,Qinghai FAN,Zixia QIAO,Qin YANG,Yabo WANG,Xiaochang WANG

期刊论文

Influence of coagulation bath on morphology of cellulose membranes prepared by NMMO method

LU Yangcheng, WU Yingxin

期刊论文

Development of combined coagulation-hydrolysis acidification-dynamic membrane bioreactor system for treatment

Xue Shen, Lei Lu, Baoyu Gao, Xing Xu, Qinyan Yue

期刊论文

Optimization and modeling of coagulation-flocculation to remove algae and organic matter from surface

Ziming Zhao, Wenjun Sun, Madhumita B. Ray, Ajay K Ray, Tianyin Huang, Jiabin Chen

期刊论文

Prediction of hydro-suction dredging depth using data-driven methods

期刊论文

Alteration of heat shock protein 20 expression in preeclamptic patients and its effect in vascular and coagulation

Fanfan Li, Mengzhou He, Meitao Yang, Yao Fan, Yun Chen, Xi Xia, Yin Xie, Dongrui Deng

期刊论文