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1.
Endocrine disrupting compounds(EDCs) and pharmaceuticals pose a challenge for water and wastewater treatment because they exist at very low concentrations in the presence of substances at much higher concentrations competing for adsorption sites.Sub-micron sized resin particles(approximately 300 nm in diameter)(SMR) were tested to evaluate their potential as a treatment for EDCs including:17-β estradiol(E2),17-α ethinylestradiol(EE2),estrone(E1),bisphenol A(BPA),and diethylstilbestrol(DES) as well as 12 pharmaceuticals.SMR were able to remove 98%of spiked E2,80%of EE2,87%of BPA,and up to 97%of DES from water.For a 0.5 ppm mixture of E2,EE2,E1,BPA and DES,the minimum removal was24%(E2) and the maximum was 49%(DES).They were also able to remove the pharmaceuticals from deionized water and wastewater.Overall,SMR are a promising advanced treatment for removal of both EDCs and pharmaceuticals. 相似文献
2.
The kinetics of adsorption and parameters of equilibrium adsorption of Methylene Blue(MB)on hybrid laponite-multi-walled carbon nanotube(NT)particles in aqueous suspensions were determined.The laponite platelets were used in order to facilitate disaggregation of NTs in aqueous suspensions and enhance the adsorption capacity of hybrid particles for MB.Experiments were performed at room temperature(298 K),and the laponite/NT ratio(X_l)was varied in the range of 0–0.5.For elucidation of the mechanism of MB adsorption on hybrid particles,the electrical conductivity of the system as well as the electrokinetic potential of laponite-NT hybrid particles were measured.Three different stages in the kinetics of adsorption of MB on the surface of NTs or hybrid laponite-NT particles were discovered to be a fast initial stage Ⅰ(adsorption time t=0–10 min),a slower intermediate stage Ⅱ(up to t=120 min)and a long-lasting final stage Ⅲ(up to t=24 hr).The presence of these stages was explained accounting for different types of interactions between MB and adsorbent particles,as well as for the changes in the structure of aggregates of NT particles and the long-range processes of restructuring of laponite platelets on the surface of NTs.The analysis of experimental data on specific surface area versus the value of X_l evidenced in favor of the model with linear contacts between rigid laponite platelets and NTs.It was also concluded that electrostatic interactions control the first stage of adsorption at low MB concentrations. 相似文献
3.
活性炭催化氧化处理电镀厂含氰废水 总被引:8,自引:0,他引:8
本文在理论研究成果基础上尝试活性炭催化氧化处理电镀厂含氰废水的运行试验,结果表明三相流化床工艺由于传质性能优越,处理效率高,配合固定床可连续实现废水的达标排放,给企业带来了良好的环境与经济效益. 相似文献
4.
Song Cheng Libo Zhang Aiyuan MaHongying Xi Jinhui PengChunyang Li Jianhua Shu 《环境科学学报(英文版)》2018,30(3):92-102
The methylene blue(MB)removal abilities of raw activated carbon and iron/cerium modified raw activated carbon(Fe–Ce-AC)by adsorption were researched and compared.The characteristics of Fe–Ce-AC were examined by N_2adsorption,zeta potential measurement,FTIR,Raman,XRD,XPS,SEM and EDS.After modification,the following phenomena occurred:The BET surface area,average pore diameter and total pore volume decreased;the degree of graphitization also decreased.Moreover,the presence of Fe_3O_4led to Fe–Ce-AC having magnetic properties,which makes it easy to separate from dye wastewater in an external magnetic field and subsequently recycle.In addition,the equilibrium isotherms and kinetics of MB adsorption on raw activated carbon and Fe–Ce-AC were systematically examined.The equilibrium adsorption data indicated that the adsorption behavior followed the Langmuir isotherm,and the pseudo-second-order model matched the kinetic data well.Compared with raw activated carbon,the maximum monolayer adsorption capacity of Fe–Ce-AC increased by27.31%.According to the experimental results,Fe–Ce-AC can be used as an effective adsorbent for the removal of MB from dye wastewater. 相似文献
5.
Removal of airborne microorganisms emitted from a wastewater treatment
oxidation ditch by adsorption on activated carbon 总被引:1,自引:0,他引:1
Bioaerosol emissions from wastewater and wastewater treatment processes are a significant subgroup of atmospheric aerosols. Most
previous work has focused on the evaluation of their biological risks. In this study, however, the adsorption method was applied to reduce
airborne microorganisms generated from a pilot scale wastewater treatment facility with oxidation ditch. Results showed adsorption
on granule activated carbon (GAC) was an e cient method for the purification of airborne microorganisms. The GAC itself had a
maximum adsorption capacity of 2217 CFU/g for airborne bacteria and 225 CFU/g for fungi with a flow rate of 1.50 m3/hr. Over 85%
of airborne bacteria and fungi emitted from the oxidation ditch were adsorbed within 80 hr of continuous operation mode. Most of them
had a particle size of 0.65–4.7 m. Those airborne microorganisms with small particle size were apt to be adsorbed. The SEM/EDAX,
BET and Boehm’s titration methods were applied to analyse the physicochemical characteristics of the GAC. Relationships between
GAC surface characteristics and its adsorption performance demonstrated that porous structure, large surface area, and hydrophobicity
rendered GAC an e ective absorber of airborne microorganisms. Two regenerate methods, ultraviolet irradiation and high pressure
vapor, were compared for the regeneration of used activated carbon. High pressure vapor was an e ective technique as it totally
destroyed the microorganisms adhered to the activated carbon. Microscopic observation was also carried out to investigate original and
used adsorbents. 相似文献
6.
Chompoonoot Nanthamathee 《环境科学学报(英文版)》2019,31(7):68-79
In this research, for the first time, a series of Co(Ⅱ) doped copper terephthalate(Co X-Cu BDC,where X is doping percentage) were successfully synthesized via solvothermal method and were tested for dye removal application. The physical properties of Co X-CuBDC were studied by several techniques including X-ray diffraction(XRD), field emission scanning electron microscopy(FESEM), energy-dispersive spectroscopy(EDS), thermogravimetric analysis(TGA)and Brunauer–Emmett–Teller(BET) surface area analysis. The incorporation of Co(Ⅱ) dopant leads to isomorphic substitution of Cu(II) in the CuBDC framework with the maximum doping percentage of 22. Doping and parent MOFs which are non-porous were used for removal of Methylene Blue(MB) from aqueous solution. Adsorption capacity of Co22-CuBDC and CuBDC are 52 and 58 mg/g, respectively, both of which are higher than the adsorption capacity recorded from several high porosity MOFs. Adsorption kinetic studies indicate that adsorption process follows pseudo-second order model while the adsorption mechanism is dominated by electrostatic attraction. Overall, even though these materials show non-porous characteristic,it can be used effectively in wastewater treatment application. 相似文献
7.
Aluminum and ferric salts are commonly used in municipal wastewater treatment plants(WWPTs) for phosphorus(P) removal. In this study, on-site jar tests were conducted to determine the removal of different P species from the fresh samples in the presence and absence of activated sludge(AS) with different doses of alum, poly-aluminum chloride,and ferric chloride at different p H. The soluble P(SP) concentration in the samples was about 0.63 mg/L. When the mixed liquor containing AS was treated with 8 mg/L of Al, SP could be reduced to 0.13 mg/L, while it was reduced to 0.16 mg/L with only 1 mg/L of Al after sedimentation removal of AS from sample. Chemical analysis determined that AS contained 59.8 mg-P/g-TSS and 43.8 mg-Al/g-TSS and most of the P was associated with the aluminum hydroxide. We discovered that the phosphate in the AS could readily be released from it, which was mainly responsible for ineffective removal of P to low levels in mixed liquor even with very high alum dose. This study provides new insight into the behavior and fate of P in the wastewater treatment plants that use alum to enhance P removal in the final effluent. 相似文献
8.
以核桃壳为原料,利用溶剂热法制备了磁性炭微球(MCMs),结合表面印迹技术制备了基于MCMs的磁性炭微球表面分子印迹材料(MMIPs).通过FT-IR、TGA、VSM和TEM等表征手段对其理化性能进行了表征,结果表明MMIPs为球形,印迹聚合层厚度50~80 nm,具有热稳定性和磁稳定性.采用吸附实验研究了MMIPs对AMP的识别与选择性吸附性能.Langmuir等温模型能较好地描述MMIPs对AMP的吸附平衡数据,25℃时MMIPs的单分子层最大吸附容量为40.96 mg·g-1.准二级动力学模型能较好的描述MMIPs对AMP吸附动力学行为.选择性分析结果表明,MMIPs对AMP具有较好地选择识别性,并且MMIPs可以循环使用5次.结合高效液相色谱分析技术,MMIPs已成功应用于牛奶样品中痕量AMP的分离、富集和回收,AMP的回收率为92.78%. 相似文献
9.
Xiaoyan Y.Ma Ke Dong Lei Tang Yongkun Wang Xiaochang C.Wang Huu Hao Ngo Rong Chen Na Wang 《环境科学学报(英文版)》2020,32(8):119-127
Currently, the wastewater treatment plants(WWTPs) attempt to achieve the shifting from general pollution parameters control to reduction of organic micropollutants discharge. However, they have not been able to satisfy the increasing ecological safety needs. In this study, the removal of micropollutants was investigated, and the ecological safety was assessed for a local WWTP. Although the total concentration of 31 micropollutants detected was reduced by 83% using the traditional biological trea... 相似文献
10.
Stereoscopic porous carbons have shown good potential in humic acid (HA) removal. In this work, a novel stereoscopic porous activated carbon (SPAC) was designed and synthesized via the self-assembly of a hydrogel based on food waste during in-situ polymerization, vacuum drying, carbonization, and activation. Then, the SPAC was functionalized with 3-aminopropyltriethoxysilane (APTES) and the adsorption behavior of the modified SPAC (SPAC-NH2) was studied systematically. The effects of pH, contact time, initial concentration of HA, and adsorbent dose were investigated, showing that optimal HA removal efficiency (> 98.0%) could be achieved at an initial HA concentration of 100?mg/L. The experimental adsorption isotherm data was fitted to the Langmuir model with a maximum adsorption capacity of 156.0?mg?HA/g SPAC-NH2. Analysis of the mechanism indicated that the removal of HA was mainly realized through the amidization reaction between the COOH groups of HA and the NH2 groups of APTES. All of the above results showed that SPAC-NH2 powder is an efficient, eco-friendly, and reusable adsorbent which is suitable for the removal of HA from wastewater. 相似文献
11.
根据炭黑疏水性的特点 ,本试验采用油团聚工艺成功地处理了炭黑废水。经处理后 ,出水中炭黑含量小于 5.0 mg/ L,出水可回用 ,回收的炭黑用四氯化碳处理后 ,经过滤干燥可得到含水率小于 1 .0 %的炭黑 ,油相可回用。 相似文献
12.
Chunxu Wu Lanfeng Li Hao Zhou Jing Ai Hongtao Zhang Jialin Tao Dongsheng Wang Weijun Zhang 《环境科学学报(英文版)》2021,33(2):340-352
This study aimed to explore the adsorption performance of sludge-based activated carbon (SBC) towards dissolved organic matters (DOMs) removal from sewage, and investigated the modification effect of different types of chemicals on the structure of synthesized SBC. Waste activated sludge (WAS) was used as a carbon source, and HCl, HNO3, and NaOH were used as different types of chemicals to modify the SBC. With the aid of chemical activation, the modified SBC showed higher adsorption performances on DOMs removal with maximum adsorption of 29.05 mg/g and second-order constant (k) of 0.1367 (L/mol/sec) due to the surface elution of ash and minerals by chemicals. The surface elemental composition of MSBC suggested that the content of C-C and C-O functional groups on the surface of modified sludge-based activated carbon (MSBC) played an important role on the adsorption capacities of MSBC towards DOMs removal in sewage. Additionally, the residual molecular weight of DOMs in sewage was investigated using a 3-dimension fluorescence excitation-emission matrix (3D-EEM) and high-performance size exclusion chromatography (HP-SEC). Results showed that the chemical modification significantly improved the adsorption capacity of MSBC on humic acids (HA) and aromatic proteins (APN), and both of NaOH-MSBC and HCl-MSBC were effective for a wide range of different AMW DOMs removal from sewage, while the HNO3-MSBC exhibited poorly on AMW organics of 2,617 Da and 409 Da due to the reducing content of macropore. In brief, this study provides reference values for the impact of the chemicals of the activation stage before the SBCs application. 相似文献
13.
采用Fe2+激活过硫酸盐(PS)耦合活性炭处理焦化废水生化出水.在原水TOC为86.4mg/L,色度338倍的条件下,研究PS和Fe2+投加量,初始pH值等因素对处理效果的影响.结果表明:PS和Fe2+投加量分别为1.5和4mmol/L,不调节pH值(8.0),反应60min,色度和TOC去除率可达87.17%和68.16%.经Fe2+/PS体系处理的废水采用A,B两种活性炭进行吸附处理,结果表明:B炭的吸附效果较好,且可去除Fe2+/PS体系残留的PS.B炭15g/L,反应120min时,出水色度为14倍,TOC 11.86mg/L.Fe2+激活PS氧化法耦合活性炭吸附深度处理焦化废水时,总色度去除率95.86%,总TOC去除率86.27%.对生化出水,Fe2+/PS体系出水和活性炭吸附出水进行三维荧光光谱扫描分析,结果表明:Fe2+/PS体系能氧化分解废水中部分类腐植酸物质,而活性炭吸附则可进一步去除了废水中残留的类腐植酸物质. 相似文献
14.
采用活性碳纤维(ACF)活化过硫酸盐(PMS)深度处理焦化废水生化出水,并考察了PMS浓度、ACF投加量、pH值对焦化废水生化出水中COD和色度去除效果的影响.结果表明,ACF/PMS体系比ACF/PS体系更能有效去除焦化废水中的有机物和色度.在PMS浓度为8.0 mmol·L-1、ACF投加量为4.0 g·L-1、pH约为8.0、温度为30 ℃的条件下,反应120 min后焦化废水生化出水中COD和色度的去除率分别达到88.7%和91.2%.ACF表征分析和重复利用实验结果说明,ACF具有较好的吸附和催化性能,且重复使用稳定性较好.自由基鉴定实验表明,SO4-· 和·OH均为反应体系中起主导作用的活性自由基.三维荧光光谱显示,焦化废水生化出水中的类富里酸和类腐殖酸物质可被有效降解转化为小分子物质. 相似文献
15.
Effect of oxidation treatment on the adsorption and the stability of mercury on activated carbon 总被引:1,自引:0,他引:1
HU Chang-xing ZHOU Jin-song LUO Zhong-yang HE Sheng WANG Guang-kai CEN Ke-fa 《环境科学学报(英文版)》2006,18(6):1161-1166
Oxidation treatment on the adsorption and the stability of Hg on activated carbon (AC) was inrestigated. Both MnO2-AC and FeCl3-AC were produced during oxidation treatment. The measurement of modified AC's mercury adsorption capacity was conducted in a simulated coal-fired flue gas by adsorbing test apparatus. TCLP and column leaching methods were used to test the stability of mercury adsorbed on ACs. The results indicate that the oxidation treatment changed the pore structure of the AC and modified the carbon surface by creating chemical components such as MnO4^-, Mn^4+, O, NO^3-, Fe^3+, Cl^-, etc. The Hg sorption capacity on MnO2-AC or FeCl3-AC was about three times higher than that of untreated carbon. In addition, the mercury control cost of each of the formers was about the half cost of the untreated carbon. The stability of Hg absorption was studied, it found that mercury adsorbed on the oxidation treated AC was not better than that of untreated carbon. It could concluded that the insoluble form of Hg is very important to the stability of mercury adsorbed on AC. This study suggests that the FeCl3-AC is the best absorbent for Hg with high adsorption capacity, better Hg adsorption stability in leaching environment, and lower cost among the three ACs tested. 相似文献
16.
Xi Yang Honghong Yi Xiaolong Tang Shunzheng Zhao Zhongyu Yang Yueqiang M Tiecheng Feng Xiaoxu Cui 《环境科学学报(英文版)》2018,30(5):104-114
This work was undertaken to investigate the behaviors and kinetics of toluene adsorption and desorption on activated carbons with varying pore structure. Five kinds of activated carbon from different raw materials were selected. Adsorption isotherms and breakthrough curves for toluene were measured. Langmuir and Freundlich equations were fitted to the equilibrium data, and the Freundlich equation was more suitable for simulating toluene adsorption. The process consisted of monolayer, multilayer and partial active site adsorption types. The effect of the pore structure of the activated carbons on toluene adsorption capacity was investigated. The quasi-first-order model was more suitable for describing the process than the quasi-second-order model. The adsorption data was also modeled by the internal particle diffusion model and it was found that the adsorption process could be divided into three stages. In the external surface adsorption process, the rate depended on the specific surface area. During the particle diffusion stage, pore structure and volume were the main factors affecting adsorption rate. In the final equilibrium stage, the rate was determined by the ratio of meso-and macro-pores to total pore volume. The rate over the whole adsorption process was dominated by the toluene concentration. The desorption behavior of toluene on activated carbons was investigated,and the process was divided into heat and mass transfer parts corresponding to emission and diffusion mechanisms, respectively. Physical adsorption played the main role during the adsorption process. 相似文献
17.
Nabisab Mujawar Mubarak Jaya Narayan Sahu Ezzat Chan Abdullah Natesan Subramanian Jayakumar 《环境科学学报(英文版)》2016,28(7):143-155
Multiwall carbon nanotubes(MWCNTs) were synthesized using a tubular microwave chemical vapor deposition technique, using acetylene and hydrogen as the precursor gases and ferrocene as catalyst. The novel MWCNT samples were tested for their performance in terms of Pb(Ⅱ)binding. The synthesized MWCNT samples were characterized using Fourier Transform Infrared(FT-IR), Brunauer, Emmett and Teller(BET), Field Emission Scanning Electron Microscopy(FESEM) analysis, and the adsorption of Pb(Ⅱ) was studied as a function of p H,initial Pb(Ⅱ) concentration, MWCNT dosage, agitation speed, and adsorption time, and process parameters were optimized. The adsorption data followed both Freundlich and Langmuir isotherms. On the basis of the Langmuir model, Qmaxwas calculated to be 104.2 mg/g for the microwave-synthesized MWCNTs. In order to investigate the dynamic behavior of MWCNTs as an adsorbent, the kinetic data were modeled using pseudo first-order and pseudo second-order equations. Different thermodynamic parameters, viz., ΔH0, ΔS0and ΔG0were evaluated and it was found that the adsorption was feasible, spontaneous and endothermic in nature. The statistical analysis revealed that the optimum conditions for the highest removal(99.9%) of Pb(Ⅱ) are at p H 5, MWCNT dosage 0.1 g, agitation speed 160 r/min and time of 22.5 min with the initial concentration of 10 mg/L. Our results proved that microwave-synthesized MWCNTs can be used as an effective Pb(Ⅱ) adsorbent due to their high adsorption capacity as well as the short adsorption time needed to achieve equilibrium. 相似文献
18.
用20%硝酸改性活性碳毡,利用扫描电镜和傅里叶红外光谱等技术对其改性后的结构进行了表征;利用改性活性碳毡作为吸附电极,进一步研究了其应用于电吸附的除盐效果和影响因素.结果表明,改性后的活性碳毡上的羰基和羧基增多,比表面积增大了32.2%,平均孔径提高了2.5%,微孔体积增大了23.1%.在电压为1.2V,pH值为6~8,极板间距为5mm时电吸附装置对水中Zn2+的吸附效果最优,动力学分析表明改性活性碳毡吸附Zn2+更符合准二级动力学方程,吸附等温线符合Langmuir等温吸附模型,除此以外,电吸附循环实验表明用20%硝酸为再生液,通过电极反接,改性活性碳毡的再生率> 74%,说明在电吸附Zn2+过程中改性活性碳毡具有良好的再生性. 相似文献
19.
To use stabilized nanoparticles(NPs) in water as disinfectants over a very long period, the amount of coating agent(for NP stabilization) needs to be optimized. To this end, silver nanoparticles(Ag-NPs) with two different coating densities of tri-sodium citrate(12.05 and46.17 molecules/nm~2, respectively), yet of very similar particle size(29 and 27 nm, respectively)were synthesized. Both sets of citrate capped NPs were then separately impregnated on plasma treated activated carbon(AC), with similar Ag loading of 0.8 and 0.82 wt.%, respectively. On passing contaminated water(containing 10~4 CFU Escherichia coli/m L of water) through a continuous flow-column packed with Ag/AC, zero cell concentration was achieved in 22 and 39 min, with Ag-NPs(impregnated on AC, named as Ag/AC) having lower and higher coating density, respectively. Therefore, even on ensuring similar Ag-NP size and loading, there is a significant difference in antibacterial performance based on citrate coating density in Ag/AC.This is observed in lower coating density case, due to both:(i) higher Ag~+ ion release from Ag-NP and(ii) stronger binding of individual Ag-NPs on AC. The latter ensures that, Ag-NP does not detach from the AC surface for a long duration. TGA-DSC shows that Ag-NPs with a low coating density bind to AC with 4.55 times higher adsorption energy, compared to Ag/AC with a high coating density, implying stronger binding. Therefore, coating density is an important parameter for achieving higher antibacterial efficacy, translating into a faster decontamination rate in experiments, over a long period of flow-column operation. 相似文献
20.
活性炭负载纳米TiO2对腐殖酸光催化降解动力学 总被引:1,自引:0,他引:1
采用溶胶-凝胶法制备了以颗粒活性炭(GAC)为载体的纳米TiO2/AC复合催化剂,并将其用于腐殖酸的光催化降解.动力学研究表明,TiO2/AC光催化降解腐殖酸过程可用Langmuir-Hinshelwood(L-H)动力学模式表示.L-H表观反应速率常数KLH=0.1124mg·L-·1min-1,吸附平衡常数K*=0.3402L·mg-1.活性炭负载TiO2对腐殖酸的光催化降解过程,体现了活性炭与TiO2的协同作用,活性炭的吸附作用提高了光催化反应速率. 相似文献