共查询到20条相似文献,搜索用时 31 毫秒
1.
Marla C. MANIQUIZ Lee-Hyung KIM Soyoung LEE Jiyeon CHOI 《Frontiers of Environmental Science & Engineering》2012,6(5):612-619
A structured stormwater infiltration system was developed and constructed at a university campus and monitoring of storm events was performed during a one-year operation period. The flow and pollutant mass balances were analyzed and the overall efficiency of the system was assessed. While significant positive correlations were observed among rainfall, runoff and discharge volume (R 2= 0.93-0.99; p <0.05), there was no significant correlations existed between rainfall, runoff, discharge volume and pollutant load. The system was more effective in reducing the runoff volume by more than 50% for small storm events but the difference between the runoff and discharge volume was significant even with rainfall greater than 10 mm. Results showed that the pollutant reduction rates were higher compared to the runoff volume reduction. Average pollutant reduction rates were in the range of 72% to 90% with coefficient of variation between 0.10 and 0.46. Comparable with runoff reduction, the system was more effective in reducing the pollutant load for small storm events, in the range of 80% to 100% for rainfall between 0 and 10 mm; while 65% to 80% for rainfall between 10 and 20 mm. Among the pollutant parameters, particulate matters was highly reduced by the system achieving only a maximum of 25% discharge load even after the entire runoff was completely discharged. The findings have proven the capability of the system as a tool in stormwater management achieving both flow reduction and water quality improvement. 相似文献
2.
Xue BAI Hanchang SHI Zhengfang YE Qiujin SUN Qing WANG Zhongyou WANG 《Frontiers of Environmental Science & Engineering》2013,7(6):844-850
In this study, microorganisms (named B111) were immobilized on polyvinyl alcohol microspheres prepared by the inverse suspension crosslinked method. The biodegradation of bisphenol A (BPA) and 4-hydro- xybenzaldehyde, a degradation product of BPA, by free and immobilized B lll was investigated. The BPA degradation studies were carried out at initial BPA concentrations ranging from 25 to 150 mg·L^-1. The affinity constant Ks and maximum degradation rate Rmax were 98.3 mg·L^-1 and 19.7mg·mg^-1VSS·d^-1 for free B111, as well as 87.2mg·L^-1 and 21.1mg·mg^-1VSS·d^-1 for immobilized B 111, respectively. 16S rDNA gene sequence analyses confirmed that the dominant genera were Pseudomonas and Brevundimonas for BPA biodegradation in microorganisms B 111. 相似文献
3.
In this paper, a study was conducted on the effect of polyhydroxyalkanoates (PHA) and glycogen transformations on biologic nitrogen and phosphorus removal in low dissolved oxygen (DO) systems. Two laboratory-scale sequencing batch reactors (SBR1 and SBR2) were operating with anaerobic/aerobic (low DO, 0.15–0.45 mg·L-1) configurations, which cultured a propionic to acetic acid ratio (molar carbon ratio) of 1.0 and 2.0, respectively. Fewer poly-3-hydroxybutyrate (PHB), total PHA, and glycogen transformations were observed with the increase of propionic/acetic acid, along with more poly-3-hydroxyvalerate (PHV) and poly-3-hydroxy-2-methyvalerate (PH2MV) shifts. The total nitrogen (TN) removal efficiency was 68% and 82% in SBR1 and SBR2, respectively. In the two SBRs, the soluble ortho-phosphate (SOP) removal efficiency was 94% and 99%, and the average sludge polyphosphate (poly-P) content (g·g-MLVSS-1) was 8.3% and 10.2%, respectively. Thus, the propionic to acetic acid ratio of the influent greatly influenced the PHA form and quantity, glycogen transformation, and poly-P contained in activated sludge and further determined TN and SOP removal efficiency. Moreover, significant correlations between the SOP removal rate and the (PHV+ PH2MV)/PHA ratio were observed (R 2>0.99). Accordingly, PHA and glycogen transformations should be taken into account as key components for optimizing anaerobic/aerobic (low DO) biologic nitrogen and phosphorus removal systems. 相似文献
4.
Guangyin ZHEN Xueqin LU Baoying WANG Youcai ZHAO Xiaoli CHAI Dongjie NIU Tiantao ZHAO 《Frontiers of Environmental Science & Engineering》2014,8(2):267-276
In this work, the enhanced dewaterabing characteristics of waste activated sludge using Fenton pretreatment was investigated in terms of effectiveness and statistical optimization. Response surface method (RSM) and central composite design (CCD) were applied to evaluate and optimize the effectiveness of important operational parameters, i.e., H202 concentrations, Fe2+ concentrations and initial pH values. A significant quadratic polynomial model was obtained (R2= 0.9189) with capillary suction time (CST) reduction efficiency as the response. Numerical optimization based on desirability function was carried out. The optimum values for H202, Fe2, and initial pH were found to be 178 mg-g-1 VSS (volatile suspended solids), 211mg.gI VSS and 3.8, respectively, at which CST reduction efficiency of 98.25% could be achieved. This complied well with those predicted by the established polynomial model. The results indicate that Fenton pretreatment is an effective technique for advanced waste activated sludge dewatering. The enhancement of sludge dewaterability by Fenton's reagent lies in the migration of sludge bound water due to the disintegration of sludge flocs and microbial cells lysis. 相似文献
5.
为研究乌鲁木齐市米东区大气降水中的化学组分特征及来源,对2017-2019年降水中主要离子浓度及来源进行了分析.研究结果显示,米东区2017-2019年降水的雨量加权pH年均值为7.95,雨量加权平均电导率年均值为16.15 mS·m-1,雨量加权平均总离子浓度为72.75-95.89 μeq·L-1,年均浓度为81.... 相似文献
6.
Jinzhong LI Xueju LI Shujuan SUN Xuegong LIU Suiliang HUANG 《Frontiers of Environmental Science & Engineering》2011,5(4):573-584
A modularized and air adjustable constructed submerged plant bed (CSPB) which can be used to restore the eutrophic water is introduced in this paper. This plant bed helps hydrophyte grow under poor conditions such as frequently changed water depth, impaired water transparency, algae bloom and substantial duckweed in summer, which are not naturally suitable for growing hydrophyte. This pilot study in Waihuan River of Tianjin, China, revealed that reduction of Chemical Oxygen Demand (COD), Total Nitrogen (TN) and Total Phosphorus (TP) by the use of CSPB could be reached 30%–35%, 35%–40%, 30%–40% respectively in the growing season (from March to October) and 5%–10%, 5%–15%, 7%–20% respectively in the winter (from November to February) when the detention time was 6 d. The relationships between the concentration of COD, TN, TP and the detention time fit the first-order kinetic equation well and the coefficients of determination (R 2) were all above 0.9. The attenuation coefficients k of the kinetic equation were a function of the water temperature. When the water temperature was quite low or quite high, k was not significantly changed with increasing or decreasing water temperature. While when the temperature was in a moderate range, an increase or decrease of water temperature would lead to a rapid increase or decrease in k . 相似文献
7.
Jinghuan ZHANG Mengchang HE Chunye LIN Ke SUN Bin MEN John L. ZHOU 《Frontiers of Environmental Science & Engineering》2009,3(4):434-442
Black carbon (BC) in ten contaminated sediments from the Song-Liao watershed, NE China, was isolated upon treatments using a combustion method at 375°C, and the isolates’ sorption isotherms for phenanthrene (Phen) were determined. All sorption isotherms were nonlinear and fitted well by the Freundlich model. A negative relation was found between Freundlich sorption nonlinearity parameter (n values) and BC/total organic carbon (TOC) content of the original sediments (r2=0.687, p<0.01), indicating the dominance of BC in Phen sorption nonlinearity. The BC isolates from this industrialized region had n values of 0.342 to 0.505 and logKFOC values of 6.02 to 6.42(μg·kg−1·OC−1)/(μg·L−1) n for Phen. At a given Ce, the BC had higher Koc value than the original sediments, revealing a higher sorption capacity for BC. BC was responsible for 50.0% to 87.3% of the total sorption at Ce=0.05 Sw, clearly indicating the dominance of BC particles in overall sorption of Phen by sediments. 相似文献
8.
Keke Li Huosheng Li Tangfu Xiao Gaosheng Zhang Aiping Liang Ping Zhang Lianhua Lin Zexin Chen Xinyu Cao Jianyou Long 《Frontiers of Environmental Science & Engineering》2020,14(2):34
9.
为研究嘉兴地区嘉善冬季污染时段和清洁时段PM2.5化学组分特征,结合气象数据对2019年1月嘉兴市嘉善县善西超级站在线自动监测PM2.5及化学组分数据、气态污染物(NO2和SO2)进行了分析.结果表明,2019年1月嘉善善西超级站污染时段PM2.5浓度(97.18μg·m-3)为清洁时段(36.77μg·m-3)的2.6倍.污染时段水溶性离子浓度(41.58μg·m-3)较清洁时段(19.82μg·m-3)高21.76μg·m-3,但占比有所降低,含碳组分比例增加.OC;EC比值为3.93,可能受到燃煤及机动车排放的共同影响.低风速及高湿有利于NO2和SO2等气态污染物进行二次转化,污染时段硫转化率和氮转化率均比清洁时段高,分别增高7.93%和54.11%,说明NOx向硝酸盐二次转化较为明显,导致颗粒物浓度升高.聚类分析结果显示67.34%气流来自北方,且相应的气流轨迹上污染物浓度比周边高,说明污染物存在一定的长距离输送.结合风玫瑰图可以看出,污染主要为本地及其周边的输送,污染物的长距离输送在短时会使污染浓度突增.因此,在重点关注本地及周边污染的同时,偏北气流下的污染物区域输送不可忽视. 相似文献
10.
微生物诱导碳酸盐沉淀(MICP)可将游离的重金属离子转化为稳定的矿化物,在修复土壤重金属污染方面具有广阔的应用前景.本研究从铜陵矿区周边土壤中筛选得到1株产脲酶且耐镉矿化菌株CZW-1,16S rDNA鉴定为芽孢杆菌(Bacillus sp.),并将其利用于添加外源Ca2+的矿化固结Cd2+实验中.通过扫描电镜(SEM)、傅立叶红外光谱(FT-IR)以及X射线衍射(XRD)对矿化产物进行表征和分析.结果表明,添加一定浓度的Ca2+可促进细菌的生长,其最佳浓度为20 mmol·L-1.且Ca2+的添加可提高细菌的最小抑制浓度和促进脲酶活性,提高对Cd2+的矿化率,加钙前后的矿化率由68.93%提高到75.95%.通过对矿化物的定性分析,可知加钙前后的矿物沉淀由单一CdCO3变为CdCO3和CaCO3的复合沉淀,其表面也由严密紧实变成填满了小颗粒CdCO3的多孔状. 相似文献
11.
Fengjie ZHANG Xiaoxia OU Shuo CHEN Chunqiu RAN Xie QUAN 《Frontiers of Environmental Science & Engineering》2012,6(4):484-492
The competitive adsorption and desorption of Pb(II) and Cu(II) ions in the soil of three sites in North China were investigated using single and binary metal solutions with 0.01 mol·L-1 CaCl2 as background electrolyte. The desorption isotherms of Pb(II) and Cu(II) were similar to the adsorption isotherms, which can be fitted well by Freundlich equation (R 2>0.96). The soil in the three sites had greater sorption capacities for Pb(II) than Cu(II), which was affected strongly by the soil characteristics. In the binary metal solution containing 1∶1 molar ratio of Pb(II) and Cu(II), the total amount of Pb(II) and Cu(II) adsorption was affected by the simultaneous presence of the two metal ions, indicating the existence of adsorption competition between the two metal ions. Fourier transform infrared (FT-IR) spectroscopy was used to investigate the interaction between soil and metal ions, and the results revealed that the carboxyl and hydroxyl groups in the soil were the main binding sites of metal ions. 相似文献
12.
Yang Li Yixin Zhang Guangshen Xia Juhong Zhan Gang Yu Yujue Wang 《Frontiers of Environmental Science & Engineering》2021,15(1):1
13.
Chen Zhou Ermias Gebrekrstos Tesfamariam Youneng Tang Ang Li 《Frontiers of Environmental Science & Engineering》2023,17(9):107
14.
Comparing the adsorption behaviors of Cd,Cu and Pb from water onto Fe-Mn binary oxide,MnO2 and FeOOH
Wei XU Huachun LAN Hongjie WANG Hongming LIU Jiuhui QU 《Frontiers of Environmental Science & Engineering》2015,9(3):385
The adsorption potential of FMBO, FeOOH, MnO2 for the removal of Cd2+, Cu2+ and Pb2+ in aqueous systems was investigated in this study. Comparing to FMBO and FeOOH, MnO2 offered a much higher removal capacity towards the three metal ions. The maximal adsorption capacity of MnO2 for Cd2+, Cu2+ and Pb2+ were 1.23, 2.25 and 2.60 mmol·g-1, respectively. And that for FMBO were 0.37, 1.13, and 1.18 mmol·g-1 and for FeOOH were 0.11, 0.86 and 0.48 mmol·g-1, respectively. The adsorption behaviors of the three metal ions on the three adsorbents were all significantly affected by pH values and heavy metal removal efficiency increased with pH increased. The Langmuir and Freundlich adsorption models were used to describe the adsorption equilibrium of the three metal ions onto the three adsorbents. Results showed that the adsorption equilibrium data fitted well to Langmuir isotherm and this indicated that adsorption of metal ions occurred on the three metal oxides adsorbents limited to the formation of a monolayer. More negative charged of MnO2 surface than that of FMBO and FeOOH could be ascribed by lower pHiep of MnO2 than that of FMBO and FeOOH and this could contribute to more binding sites on MnO2 surface than that of FMBO and FeOOH. The higher metal ions uptake by MnO2 than FMBO and FeOOH could be well explained by the surface charge mechanism. 相似文献
15.
水环境中阴离子的快速便捷检测对评估流域水环境污染、提出相关流域治理对策具有重要意义.提出一种以镧系金属离子Eu3+作为配位金属离子,采用水热法与2,6-吡啶二羧酸合成镧系配合物,对水环境中9种常见阴离子进行定性和定量分析的方法.结果表明,制备的配合物吡啶二羧酸铕[Eu(DPA)3]在水中具有良好分散性,280 nm激发... 相似文献
16.
Rongfang YUAN Beihai ZHOU Duo HUA Chunhong SHI 《Frontiers of Environmental Science & Engineering》2015,9(5):850
The effect of ion-doping on TiO2 nanotubes were investigated to obtain the optimal TiO2 nanotubes for the effective decomposition of humic acids (HA) through O3/UV/ion-doped TiO2 process. The experimental results show that changing the calcination temperature, which changed the weight fractions of the anatase phase, the average crystallite sizes, the Brunauer-Emmett-Teller surface area, and the energy band gap of the catalyst, affected the photocatalytic activity of the catalyst. The ionic radius, valence state, and configuration of the dopant also affected the photocatalytic activity. The photocatalytic activities of the catalysts on HA removal increased when Ag+, Al3+, Cu2+, Fe3+, V5+, and Zn2+ were doped into the TiO2 nanotubes, whereas such activities decreased as a result of Mn2+- and Ni2+-doping. In the presence of 1.0 at.% Fe3+-doped TiO2 nanotubes calcined at 550°C, the removal efficiency of HA was 80% with a pseudo-first-order rate constant of 0.158 min−1. Fe3+ in TiO2 could increase the generation of ·OH, which could remove HA. However, Fe3+ in water cannot function as a shallow trapping site for electrons or holes. 相似文献
17.
森林被誉为"地球之肺",在防霾治污方面有其独特不可替代的作用,不同树种沉降PM2.5的功能有很大差别.本文选取代表性城市森林——奥林匹克森林公园为研究对象,设置垂直监测塔观测大气PM2.5的浓度垂直分布,以考察不同季节城市森林对PM2.5中各组分的影响.在冬季、春季和夏季各采集PM2.5样品,分析并计算PM2.5中Na+、NH4+、K+、Mg2+、Ca2+、Cl-、NO3-和SO42-等典型水溶性无机离子的浓度.结果表明,PM2.5中水溶性无机离子总浓度呈规律性变化特征:冬季((56.90±27.38)μg·m-3)>春季((46.69±12.24)μg·m-3)>夏季((23.16±8.75)μg·m-3).其中SO42-和NO3-浓度和占PM2.5主要水溶性无机离子总浓度的50%以上.3个季节中,除冬季外,在春季和夏季,8种离子有明显的垂直方向上的沉降,夏季的沉降速率高于春季,但是春季由于大气颗粒物浓度高,沉降通量高于夏季.NO3-和SO42-垂直方向的沉降量在所有可溶性无机离子中最高.植被密度、叶面积指数、气象条件等因素对于PM2.5的沉降特征有明显影响. 相似文献
18.
John WANG Peng JIN Paul L. BISHOP Fuzhi LI 《Frontiers of Environmental Science & Engineering》2012,6(2):288-293
Lagoon-based municipal wastewater treatment plants (WWTPs) are facing difficulties meeting the needs of rapid population growth as well as the more stringent requirements of discharge permits. Three municipal WWTPs were modified using a high surface area media with upgraded fine-bubble aeration systems. Performance data collected showed very promising results in terms of five-day biochemical oxygen demand (BOD5), ammonia (NH3) and total suspended solids (TSS) removal. Two-year average ammonia effluents were 4.1 mg·L-1 for Columbia WWTP, 4 mg·L-1 for Larchmont WWTP and 2.1 mg·L-1 for Laurelville WWTP, respectively. Two- year average BOD5 effluents were 6.8, 4.9 and 2.7 mg·L-1, and TSS effluents were 15.0, 9.6 and 7.5 mg·L-1. The systems also showed low fecal coliform (FC) levels in their effluents. 相似文献
19.
Xi Luo Ao Li Xue Xia Peng Liang Xia Huang 《Frontiers of Environmental Science & Engineering》2023,17(9):108
20.
Tianhao Xi Xiaodan Li Qihui Zhang Ning Liu Shu Niu Zhaojun Dong Cong Lyu 《Frontiers of Environmental Science & Engineering》2021,15(4):55