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EFFICIENT CONTAMINANT REMOVAL FROM LIQUID DIGESTATE OF PIG MANURE BY CHEMICAL PRECIPITATION AND CO MINERALIZATION

《农业科学与工程前沿(英文)》 2023年 第10卷 第3期   页码 479-491 doi: 10.15302/J-FASE-2023480

摘要:

● LFD was treated by fly ash-based chemical precipitation and CO2 mineralization.

关键词: anaerobic digestion     chemical oxygen demand     fly ash     ion removal     total phosphate    

Modification of the activated sludge model for chemical dosage

Shuai MA,Siyu ZENG,Xin DONG,Jining CHEN,Gustaf OLSSON

《环境科学与工程前沿(英文)》 2015年 第9卷 第4期   页码 694-701 doi: 10.1007/s11783-014-0732-3

摘要: Full-scale experiments have been carried out to adapt the activated sludge model ASM2d to include the influence of metal dosage (Fe and Al ) for phosphorus removal. Phosphorus removal rates, nitrification rates, as well as pH and sludge settling performance, were evaluated as functions of the metal dosages. Furthermore, models relating certain parameters to the dosage of chemicals have been derived. Corresponding parameters in the ASM2d and the secondary settler models, included in the Benchmark Simulation Model No 1 (BSM1), have been modified to take the metal influence into consideration. Based on the effluent limits and penalty policy of China, an equivalent evaluation method was derived for the total cost assessment. A large number of 300-day steady-state and 14-day open-loop dynamic simulations were performed to demonstrate the difference in behavior between the original and the modified BSM1. The results show that 1) both in low and high mole concentrations, Fe addition results in a higher phosphorus removal rate than Al ; 2) the sludge settling velocity will increase due to the metal addition; 3) the respiration rate of the activated sludge is decreased more by the dosage of Al than Fe ; 4) the inhibition of Al on the nitrification rate is stronger than that of Fe ; 5) the total operating cost will reach the minimum point for smaller dosages of Fe , but always increase with Al addition.

关键词: chemical precipitation     benchmark simulation model     phosphorus removal     respiratory rate     sludge settling     activated sludge model    

Modeling radiative effects of haze on summer-time convective precipitation over North China: a case study

Xuying WANG, Bin ZHANG

《环境科学与工程前沿(英文)》 2016年 第10卷 第4期 doi: 10.1007/s11783-016-0840-3

摘要: We modeled the impact of haze radiative effects on precipitation in North China. Shortwave heating induced by haze radiative effects would reduce heavy rainfalls. Convection was the key factor that whether precipitation was enhanced or suppressed. Precipitation was often suppressed where CAPE, RH and updraft velocities were high. The impact of haze radiative effect on summertime 24-h convective precipitation over North China was investigated using WRF model (version 3.3) through model sensitivity studies between scenarios with and without aerosol radiative effects. The haze radiative effect was represented by incorporating an idealized aerosol optical profile, with AOD values around 1, derived from the aircraft measurement into the WRF shortwave scheme. We found that the shortwave heating induced by aerosol radiative effects would significantly reduce heavy rainfalls, although its effect on the post-frontal localized thunderstorm precipitation was more diverse. To capture the key factors that determine whether precipitation is enhanced or suppressed, model grids with 24-h precipitation difference between the two scenarios exceeding certain threshold (>30 mm or<-30 mm) were separated into two sets. Analyses of key meteorological variables between the enhanced and suppressed regimes suggested that atmospheric convection was the most important factor that determined whether precipitation was enhanced or suppressed during summertime over North China. The convection was stronger over places with precipitation enhancement over 30 mm. Haze weakened the convection over places with precipitation suppression exceeding 30 mm and caused less water vapor to rise to a higher level and thus further suppressed precipitation. The suppression of precipitation was often accompanied with relatively high convective available potential energy (CAPE), relative humidity (RH) and updraft velocities.

关键词: Haze     Aerosol radiative effects     Convective precipitation    

Changes in hourly precipitation may explain the sharp reduction of discharge in the middle reach of the

Lin LUO, Zhongjing WANG

《环境科学与工程前沿(英文)》 2013年 第7卷 第5期   页码 756-768 doi: 10.1007/s11783-013-0563-7

摘要: The Hekou-Longmen reach, together with local floods, is the main source area for coarse sedimentations into the Yellow River. When total rainfall slightly increased in the area, discharge dramatically decreased by 40%–70% after the year of 2000, and attracting extensive attention in the context of global climate change. High temporal resolution precipitation (timescales between 1 and 4 h) data from the June to September period from 270 rain gauges over the past three decades was mined in order to help explain the phenomenon. Each rainfall event was classified as light/moderate rain, large rain, heavy rain or rainstorm by the event’s rainfall amount, and further classified as low intensity rain, medium intensity rain and high intensity rain by the event’s rainfall intensity. The Mann-Kendall trend test was applied to detect the presence and significance of monotonic trends, and to find the change points in the mean and variance of the precipitation characteristics series, including the amount, intensity, frequency and duration of each rainfall category. Results show that although the total amount of precipitation has slightly increased, the average rainfall intensity has significantly decreased. The larger change happened in light/moderate rain events and low/medium intensity rain events, and the intensity changes have a great extent occurred around the threshold of Non-Runoff Rainfall regime, which was proposed for the approximate calculation of initial losses. Changes in rainfall distribution between different classes of the Runoff Rainfall regime in the 2000s could lead to 0.9 mm less runoff depth (17.3% of the total reduction) than the 1980–1999 period. The study indicates that changes in hourly precipitation may be responsible for the sharp reduction of discharge.

关键词: precipitation intensity     Mann-Kendall rank statistic     spatial and temporal distribution     climatic change    

Evaluation of precipitation behavior of zirconium molybdate hydrate

Liang ZHANG, Masayuki TAKEUCHI, Tsutomu KOIZUMI, Izumi HIRASAWA

《化学科学与工程前沿(英文)》 2013年 第7卷 第1期   页码 65-71 doi: 10.1007/s11705-013-1314-9

摘要: In the dissolution step of spent nuclear fuel, there is a world-concern problem that zirconium molybdate hydrate precipitates as a byproduct, and accumulates in some reprocessing equipments. In order to prevent this accumulation, we have developed a new method based on the controlled reaction crystallization of zirconium molybdate hydrate (ZMH) in the reprocessing solution, followed by solid liquid separation. In order to measure the particle size of ZMH, batch crystallization experiments were conducted by varying nitric acid concentration and operating temperature. In result, almost all particle sizes scatter around 1 μm on average, despite the higher concentration of nitric aid and operating temperature, and then small particles grow up as an aggregate sticking to the crystallizer. Moreover, polymorph and color changing were observed by varying the concentration of nitric acid and reaction time. These results suggest that crystal color and adhesiveness are closely related to the particle size of ZMH. And the control of nitric acid concentration and small particle growth would be the useful technique to prevent the ZMH sticking.

关键词: spent nuclear fuel     zirconium molybdate hydrate     cleaning method     accumulation    

of vanadium and manganese from high-manganese containing vanadium wastewater by a solvent extraction-precipitation

Zishuai Liu, Yimin Zhang, Zilin Dai, Jing Huang, Cong Liu

《化学科学与工程前沿(英文)》 2020年 第14卷 第5期   页码 902-912 doi: 10.1007/s11705-019-1887-z

摘要: High-manganese containing vanadium wastewater (HMVW) is commonly produced during the vanadium extraction process from vanadium titano-magnetite. HMVW cannot be reused and discharged directly, and is harmful to the environment and affect product quality due to heavy metals in the wastewater. The wastewater is usually treated by lime neutralization, but valuable metals (especially V and Mn) cannot be recovered. In this study, an efficient and environmentally friendly method was developed to recover valuable metals by using a solvent extraction-precipitation process. In the solvent extraction process, 98.15% of vanadium was recovered, and the V O product, with a purity of 98.60%, was obtained under optimal conditions. For the precipitation process, 91.05% of manganese was recovered as MnCO which meets the III grade standard of HG/T 2836-2011. Thermodynamic simulation analysis indicated that MnCO was selectively precipitated at pH 6.5 while Mg and Ca could hardly be precipitated. The results of X-ray diffraction and scanning electron microscopy demonstrated that the obtained V O and MnCO displayed a good degree of crystallinity. The treated wastewater can be returned for leaching, and resources (V and Mn) in the wastewater were utilized efficiently in an environmentally friendly way. Therefore, this study provides a novel method for the coextraction of V and Mn from HMVW.

关键词: high-manganese containing vanadium wastewater     solvent extraction     carbonate precipitation     vanadium titano-magnetite     valuable metal recovery    

LiFePO/C cathode materials synthesized by co-precipitation and microwave heating

XU Yunlong, TAO Lili, MA Hongyan, HUANG Huaqing

《化学科学与工程前沿(英文)》 2008年 第2卷 第4期   页码 422-427 doi: 10.1007/s11705-008-0082-4

摘要: LiFePO/C cathode materials were synthesized by a combination of co-precipitation and microwave heating using polyethylene glycol (PEG) as a carbon resource and the influence of microwave heating time on the structure and electrochemical performance of the materials was also discussed. The samples were characterized by X-ray diffraction (XRD), TEM, particle-size analysis and constant current charge-discharge experiment. The results show that the LiFePO/C heated for 9 min has a pure olive-type phase and excellent electrochemical performance. The initial discharge capacities of this sample are 154.3, 139.7, 123.9 mAh/g at the rates 0.1C, 0.2C, 1C at room temperature, respectively, and after 20 cycles remain 152.3, 134.3, 118.5 mAh/g, respectively.

关键词: polyethylene     electrochemical performance     combination     co-precipitation     diffraction    

CLIMATE-CHANGE-INDUCED TEMPORAL VARIATION IN PRECIPITATION INCREASES NITROGEN LOSSES FROM INTENSIVE CROPPING

《农业科学与工程前沿(英文)》 2022年 第9卷 第3期   页码 457-464 doi: 10.15302/J-FASE-2022452

摘要:

● A simple model was used to evaluate how increasing temporal variability in precipitation influences crop yields and nitrogen losses.

关键词: crop yield     fertilizer timing     nitrogen loss     precipitation variability     toy model    

热带测雨卫星搭载的仪器及其探测结果

傅云飞,刘奇,王雨,孙亮,李锐,马明,刘国胜

《中国工程科学》 2012年 第14卷 第10期   页码 43-50

摘要:

针对降水遥感和探测,简要介绍了卫星红外遥感方法和被动微波遥感方法,着重讨论了热带测雨卫星及其搭载仪器。随后介绍了热带测雨卫星多仪器探测结果的应用,并以夏季热对流降水为例,分析了其降水结构、云顶高度和雨顶高度及其与地表降水之间的关系,同时也阐述了如何利用热带测雨卫星和测雨雷达长时间资料,来分析亚洲地区降水的气候分布。最后对卫星主动微波探测降水的发展做了简要展望。

关键词: 热带测雨卫星     测雨雷达     微波成像仪     光谱     降水    

Separation of 1,3-propanediol from glycerol-based fermentations of Klebsiella pneumoniae by alcohol precipitation

GAO Sujun, SUN Yaqin, XIU Zhilong

《化学科学与工程前沿(英文)》 2007年 第1卷 第2期   页码 202-207 doi: 10.1007/s11705-007-0037-1

摘要: The separation of 1,3-propanediol from the glycerol-based fermentation broth of plays an important role during the microbial production of 1,3-propanediol. In this paper, the separation of 1,3-propanediol from fermentative broth by a combination of ultrafiltration and alcohol dilution crystallization was investigated. The broth was first filtered by ultrafiltration, and 99% of cells, 89.4% of proteins and 69% of nucleic acids were removed. The obtained broth was further condensed by vac uum distillation, and then alcohol was added. The macromolecular impurities, such as nucleic acids, polysaccharides and proteins, were precipitated, and inorganic and organic salts were crystallized. The optimal volume ratio of alcohol added to the condensed fermentation broth was determined to be 2:1. As a result, proteins, nucleic acids and electric conductivity decreased by 97.4%, 89.7% and 95.8%, respectively, compared with the fermentative broth. The influences of pH and water content in condensed broth on alcohol precipitation and dilution crystallization were also investigated. The experimen tal results indicated that alcohol precipitation and dilution crystallization was feasible and effective for the separation of 1,3-propanediol from actual fermentation broth.

Preparation of ultrafine α-AlO using precipitation-azeotropic distillation method

XIAO Jin, QIN Qi, ZHOU Feng, CHEN Yanbin, WAN Ye

《机械工程前沿(英文)》 2008年 第3卷 第2期   页码 226-231 doi: 10.1007/s11465-008-0029-y

摘要: Ammonium aluminum carbonate hydroxide (AACH) was prepared by a precipitation-azeotropic distillation method, which uses aluminum sulfate as the Al source and ammonium carbonate as the precipitant. Then, AACH was calcined into ultrafine ?-AlO powder. The factors that influence the dispersion property of ultrafine ?-AlO powder are discussed in this paper, such as the methods of adding materials, surfactant, and drying methods. The changes of the structure and property of ultrafine alumina in the thermal treatment process are also studied. The morphological structure and properties of AACH are characterized by DTA/TGA, SEM, XRD, and ICP measurements. The results show that ultrafine ?-AlO powder with a uniform particle size and well-distributed property can be synthesized only after aluminum sulfate atomizes into ammonium carbonate, proper amount of PEG1000 is added as the dispersant, and the product is treated by azeotropic distillation. The phase transformation of alumina during the calcination process can be described as amorphous AlO → ?-AlO → ?-AlO → ?-AlO. The crystal grain size and density of ultrafine alumina powder increase with the increase of the calcination temperature. After AACH has been calcined at 1200°C for 2 h, the ultrafine ?-AlO with uniform particle size, spherical shape, and more than 99.97% purity is obtained and its powder is well dispersed.

关键词: calcination temperature     spherical     AACH     carbonate hydroxide     ammonium carbonate    

Combined Fenton process and sulfide precipitation for removal of heavy metals from industrial wastewater

Huosheng Li, Hongguo Zhang, Jianyou Long, Ping Zhang, Yongheng Chen

《环境科学与工程前沿(英文)》 2019年 第13卷 第4期 doi: 10.1007/s11783-019-1130-7

摘要:

Addition of alkali to pH 10 is effective for precipitation of precipitable metals.

Fenton treatment is effective for substantial removal of Tl, Cd, Cu, Pb, and Zn.

Sulfide precipitation is a final step for removal of trace Tl, Cd, Cu, Pb, and Zn.

Bench and pilot studies demonstrated the effectiveness of this combined technique.

关键词: Thallium     Pilot     Fenton     Sulfide precipitation     Heavy metal     Industrial wastewater    

Numerical investigation of the influence of kinetics and shape factor on barium sulfate precipitation

Zheng WANG, Zai-Sha MAO, Chao YANG, Qinghua ZHANG, Jingcai CHENG

《化学科学与工程前沿(英文)》 2009年 第3卷 第3期   页码 272-281 doi: 10.1007/s11705-009-0023-x

摘要: The effect of kinetics and shape factor on barium sulfate precipitation in a continuous stirred tank has been investigated numerically through solving the standard momentum and mass transport equations in combination with the moment equations for crystal population balance. The numerical method was validated with the literature data. The simulated results include the distribution of the local supersaturation ratio in the reactor, the mean crystal size, and the coefficient of variation. The simulation results show that the value of shape factor used in the model affected greatly the mean crystal size and the moments of the crystal size distribution. The influence of the kinetic expressions on the simulation is also analyzed. It is important to investigate the relationship of the shape factor with the precipitator type and other operation conditions to obtain reliable simulation results and suitable kinetic equations of crystal nucleation and growth rates.

关键词: stirred tank     numerical simulation     precipitation     shape factor     crystal kinetics    

Effect of wastewater composition on the calcium carbonate precipitation in upflow anaerobic sludge blanket

Shucheng YANG, Yanling HE, Charles CHOU, Pengxiang ZHANG, Dongqi WANG, Yonghong LIU,

《环境科学与工程前沿(英文)》 2010年 第4卷 第2期   页码 142-149 doi: 10.1007/s11783-010-0026-3

摘要: Calcium carbonate often precipitates in anaerobic reactors treating wastewater with high calcium content. The aim of this paper is to study the effect of wastewater composition on calcium carbonate precipitation in upflow anaerobic sludge blanket (UASB) reactors. Two laboratory-scale UASB reactors were operated with calcium-containing influents using acetate and carbohydrate as substrate, respectively. There was an obvious accumulation of inorganic precipitate observed in the biogranules. Observations via scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) showed that the acclimated biogranules in the two reactors differed in microstructure. Calcium carbonate was found to have precipitated on the surface of acetate-degrading biogranules, but precipitated at the core of the carbohydrate-degrading biogranules. The results indicated that substrates had significant influence on the location of calcium carbonate precipitation in anaerobic granular sludge, which was expected due to the different methanogens distribution and pH gradient within the granular sludge degrading various substrates. Moreover, the location of calcium carbonate precipitation substantially affected the specific methanogenic activity (SMA) of the granular sludge. The SMA of the acetate-degrading biogranules dropped from 1.96 gCOD·gVSS·d to 0.61 gCOD·gVSS·d after 180-d of operation in the reactor. However, the SMA of the carbohydrate-degrading biogranules was not adversely affected by calcium carbonate precipitation.

关键词: calcium carbonate     precipitation     anaerobic granular sludge     wastewater composition     microstructure     upflow anaerobic sludge blanket (UASB)    

混酸溶浸—硫化沉锡工艺处理ITO废料回收铟锡

王树楷

《中国工程科学》 2009年 第11卷 第9期   页码 34-37

摘要:

采用混酸溶浸—硫化沉锡工艺处理ITO废料,解决了料液难滤和有效回收铟和锡的问题。

关键词: ITO     废料             混酸溶浸—硫化沉锡工艺    

标题 作者 时间 类型 操作

EFFICIENT CONTAMINANT REMOVAL FROM LIQUID DIGESTATE OF PIG MANURE BY CHEMICAL PRECIPITATION AND CO MINERALIZATION

期刊论文

Modification of the activated sludge model for chemical dosage

Shuai MA,Siyu ZENG,Xin DONG,Jining CHEN,Gustaf OLSSON

期刊论文

Modeling radiative effects of haze on summer-time convective precipitation over North China: a case study

Xuying WANG, Bin ZHANG

期刊论文

Changes in hourly precipitation may explain the sharp reduction of discharge in the middle reach of the

Lin LUO, Zhongjing WANG

期刊论文

Evaluation of precipitation behavior of zirconium molybdate hydrate

Liang ZHANG, Masayuki TAKEUCHI, Tsutomu KOIZUMI, Izumi HIRASAWA

期刊论文

of vanadium and manganese from high-manganese containing vanadium wastewater by a solvent extraction-precipitation

Zishuai Liu, Yimin Zhang, Zilin Dai, Jing Huang, Cong Liu

期刊论文

LiFePO/C cathode materials synthesized by co-precipitation and microwave heating

XU Yunlong, TAO Lili, MA Hongyan, HUANG Huaqing

期刊论文

CLIMATE-CHANGE-INDUCED TEMPORAL VARIATION IN PRECIPITATION INCREASES NITROGEN LOSSES FROM INTENSIVE CROPPING

期刊论文

热带测雨卫星搭载的仪器及其探测结果

傅云飞,刘奇,王雨,孙亮,李锐,马明,刘国胜

期刊论文

Separation of 1,3-propanediol from glycerol-based fermentations of Klebsiella pneumoniae by alcohol precipitation

GAO Sujun, SUN Yaqin, XIU Zhilong

期刊论文

Preparation of ultrafine α-AlO using precipitation-azeotropic distillation method

XIAO Jin, QIN Qi, ZHOU Feng, CHEN Yanbin, WAN Ye

期刊论文

Combined Fenton process and sulfide precipitation for removal of heavy metals from industrial wastewater

Huosheng Li, Hongguo Zhang, Jianyou Long, Ping Zhang, Yongheng Chen

期刊论文

Numerical investigation of the influence of kinetics and shape factor on barium sulfate precipitation

Zheng WANG, Zai-Sha MAO, Chao YANG, Qinghua ZHANG, Jingcai CHENG

期刊论文

Effect of wastewater composition on the calcium carbonate precipitation in upflow anaerobic sludge blanket

Shucheng YANG, Yanling HE, Charles CHOU, Pengxiang ZHANG, Dongqi WANG, Yonghong LIU,

期刊论文

混酸溶浸—硫化沉锡工艺处理ITO废料回收铟锡

王树楷

期刊论文