共查询到20条相似文献,搜索用时 578 毫秒
1.
A novel cellulose-based adsorbent, iron(III)-coordinated amino-functionalised poly(glycidylmethacrylate)-grafted cellulose [Fe(III)–AM-PGMACell] was developed for the removal of phosphate from water and wastewater. The scanning electron micrograph showed that AM-PGMACell has a rougher surface than cellulose and the adsorption of Fe(III) on AM-PGMACell made the surface even rougher. Infrared spectroscopy revealed that amino groups on the surface of AM-PGMACell complexed with Fe(III) played an important role in the removal of phosphate from solutions. X-Ray diffraction patterns showed a decrease in crystallinity after graft copolymerisation onto cellulose. The effects of contact time, initial sorbate concentration, pH, agitation speed, dose of adsorbent and temperature on the removal process were investigated. Maximum removal of 99.1% was observed for an initial concentration of 25 mg·L ?1 at pH 6.0 and an adsorbent dose of 2.0 g·L ?1. A two-step pseudo-first-order kinetic model and Sips isotherm model represented the measured data very well. Complete removal of 11.6 mg·L ?1 phosphate from fertiliser industry wastewater was achieved by 1.6 g·L ?1 Fe(III)–AM-PGMACell. The adsorbent exhibited very high reusability for several cycles. Overall, the study demonstrated that Fe(III)–AM-PGMACell can be used as an efficient adsorbent for the removal and recovery of phosphate from water and wastewater. 相似文献
2.
杭锦2~#土复合吸附剂对磷的吸附动力学 总被引:1,自引:0,他引:1
通过静态试验考察杭锦2#土/聚合硫酸铝复合吸附剂对生活污水中磷酸根的吸附特性,研究吸附过程的动力学模型,并从动力学角度探讨其吸附机理。结果表明,在杭锦2#土/聚合硫酸铝复合吸附剂用量5 g.L-1、吸附时间60 min、废水pH值6.0、温度25℃、磷初始质量浓度小于16.72 mg.L-1条件下,磷酸根的去除率在96%以上;复合吸附剂对磷酸根的吸附动力学特征符合假二级方程,吸附速率在前10 min为内扩散控制,后期由膜扩散和内扩散共同控制,且膜扩散占主导地位;磷酸根的初始浓度越高,吸附质粒子的表观内扩散系数和表观传质系数越小;使用不同再生次数的再生吸附剂(添加量为5 g.L-1)处理16.72 mg.L-1含磷生活污水,随着再生次数的增加,吸附能力有所下降,但磷酸根的去除率均大于89%。 相似文献
3.
Pollution of water bodies by trace metals is an established problem and several studies have been conducted to deal with it. South Africa is amongst those countries whose water systems are most affected as a result of intensive mining activities. This research was dedicated to the development of an insoluble chelating polymer for use as an adsorbent for abstraction of metal ions from mining and industrial wastewaters. Polyethylenimine (PEI), well known for its metal chelating potential, was cross-linked by epichlorohydrin (ECH) in order to convert it into a water-insoluble form for direct use as an adsorbent. The binding affinity of the cross-linked polyethylenimine (CPEI) to heavy metal ions was assessed as well as its ability to be regenerated for re-use. CPEI exhibited good complexation ability to metal ions with high affinity to Cr and most divalent metal ions. The observed order of complexation was: Cr?>?Zn>?Fe?>?Ni?>?Mn?>?Pb. On the other hand, it showed very poor ability to bind oxo-anions such as SeO3 2? and AsO2 ? which has been attributed to the unavailability of suitable functional groups to interact with these ions. 相似文献
4.
Jiachuang Shao Penghui Shao Mingming Peng Min Li Ziwei Yao Xiuqin Xiong Caiting Qiu Yufan Zheng Liming Yang Xubiao Luo 《Frontiers of Environmental Science & Engineering》2023,17(3):33
5.
In this study, high capacity Chestnut shell, a waste product from the chestnut sugar production industry, was successfully applied to remove Pb (II) and Cd (II) ions from aqueous solutions. Maximum adsorption capacities were found as 541.25?mg/g and 75.86?mg/g for Pb(II), and Cd(II) respectively. Several important parameters influencing the adsorption of Pb(II) and Cd(II) ions such as contact time, pH, temperature and effect of metal concentration were investigated systematically by batch experiments. Langmuir and Freundlich adsorption models were used to describe adsorption isotherms and constants. The thermodynamic parameters, such as standard free energy (ΔG°), standard enthalpy (ΔH°), and standard entropy (ΔS°), of the adsorption process were calculated. The adsorbents were characterised by scanning electron microscopy. It has been observed from the experimental results that in case of both Cd (II) and Pb (II), pseudo 2nd order kinetic model. From the results, Chestnut Shell are considered as an effective, low cost and environmental friendly adsorbent for the removal of Pb (II) and Cd (II) from wastewater. 相似文献
6.
改性活性氧化铝除磷性能的试验 总被引:3,自引:0,他引:3
为提高活性氧化铝对废水中磷的去除效果,以硫酸铝为改性剂,采用浸渍法对其进行改性;测定了改性前后活性氧化铝的比表面积及孔容孔径;考察了吸附时间、pH、废水初始浓度、改性剂投加量等因素对去除废水中磷的影响;探讨了改性活性氧化铝对磷的吸附机理.结果表明,改性后活性氧化铝的比表面积为398.364 m2/g,提高了14.22%... 相似文献
7.
活性污泥吸附预处理重油裂化制气废水 总被引:2,自引:0,他引:2
利用剩余活性污泥对含有高浓度芳香族化合物的重油裂化制气废水进行预处理的研究并提出了合适的吸附条件。结果表明,活性污泥吸附预处理对COD和悬浮物有明显的去除效果,而且可以提高废水BOD5/COD的比值,另外还有降解芳香族化合物的作用,使进入生物处理系统的废水的可生物降解性有明显的改善。这一方法为利用普通废水生物处理系统中产生的剩余活性污泥来预处理难降解的工业废水提供了一条有效的途径。 相似文献
8.
The use of Rooibos shoots, a natural adsorbent, for cadmium removal from wastewater is proposed. The effects of initial pH, adsorbent dosage, contact time, and initial concentration were investigated in the batch adsorption mode. The optimum pH was found to be 5.5. Isotherm and kinetic data were modeled; the data fitted best to the Freundlich model, and, kinetically, the adsorption was of pseudo-second order as shown by the high R2 value of 0.9928 along with close agreement between the experimental qe (13.9 mg g?1) and calculated qe (14.24 mg g?1) values. The studied biomass material was found to be effectively used for removal of cadmium from contaminated mine wastewater. 相似文献
9.
Ganesan Surendran 《Chemistry and Ecology》2018,34(8):762-785
Sorghastrum Nutans L. Nash is used as an adsorbent for the removal of Cr(VI) from wastewater. Adsorption coupled reduction i.e. indirect reduction is the mechanism of Cr(VI) removal by the biomaterial. The adsorbent surface became highly positively charged at lower pH, adsorption rate of Cr(VI) is faster and reduction reaction also accelerates at lower pH since the binding of negatively charged Cr(VI) ion species to the cationic groups is enhanced and protons take part in this reaction. The adsorbent is characterised by using XRD, FTIR, SEM and EDAX analysis. OH bending, CN stretching/bending and NH stretching play a major role in Chromium adsorption. Experimental values follow pseudo-second order reaction and Langmuir adsorption isotherm. Surface diffusion is the rate controlling mechanism for the process. The maximum percentage of Cr(VI) removal obtained is 75.5% with 7?g/L dosage at pH 1.3 and adsorbate concentration was 100?mg/L. From the normal probability, residual, contour, 3D surface, main effect and interaction plot along with t-test, ANOVA, and F-test, it is observed that pH has the most significant effect on the percentage removal followed by adsorbent dosage and time. The adsorbate concentration has the least effects and interaction effects are found to be significant. 相似文献
10.
The present work describes the removal of Novacron Golden Yellow (NGY) dye from aqueous solutions using peanut hulls. The experiments were performed with native, pretreated and immobilised forms of peanut hulls. The effect of various operational parameters (pH, biosorbent dose, initial dye concentration and temperature etc.) was explored during batch study. NGY showed maximum removal at low pH and low biosorbent dose. High initial dye concentration facilitated the biosorption process. Maximum dye removal with native, pretreated and immobilised biomass was found to be 35.7, 36.4 and 15.02 mg/g respectively. The experimental data were subjected to different kinetic and equilibrium models. The kinetic data confirmed the fitness of pseudo-second-order rate law for NGY biosorption. The equilibrium modelling was carried out by Freundlich, Langmuir and Temkin models. The isothermal data of NGY removal were best described by Freundlich adsorption isotherm. Negative values of Free energy change (Δ G0) for NGY with native and pretreated biomass depicted the spontaneous nature of biosorption process. In column mode, the effects of bed height, flow rate and initial dye concentrations were optimised. Maximum NGY biosorption (7.28 mg/g) was observed with high bed height, low flow rate and high initial concentration in continuous mode. Bohart–Adams model best fitted to the data obtained from column studies. The results indicated that the peanut hulls could be used effectively for the removal of dyes containing wastewater. 相似文献
11.
Fatih Ilhan Kubra Ulucan-Altuntas Yasar Avsar Ugur Kurt Arslan Saral 《Frontiers of Environmental Science & Engineering》2019,13(5):73
12.
Md. Lutfor RAHMAN Shaheen M. SARKAR Mashitah Mohd YUSOFF 《Frontiers of Environmental Science & Engineering》2016,10(2):352-361
Poly(hydroxamic acid)-poly(amidoxime) chelating ligands were synthesized from poly(methyl acrylate-co-acrylonitrile) grafted acacia cellulose for removing toxic metal ions from industrial wastewaters. These ligands showed higher adsorption capacity to copper (2.80 mmol?g−1) at pH 6. In addition, sorption capacities to other metal ions such as iron, zinc, chromium, and nickel were also found high at pH 6. The metal ions sorption rate (t1/2) was very fast. The rate of adsorption of copper, iron, zinc, chromium, nickel, cobalt, cadmium and lead were 4, 5, 7, 5, 5, 8, 9 and 11 min, respectively. Therefore, these ligands have an advantage to the metal ions removal using the column technique. We have successfully investigated the known concentration of metal ions using various parameters, which is essential for designing a fixed bed column with ligands. The wastewater from electroplating plants used in this study, having chromium, zinc, nickel, copper and iron, etc. For chromium wastewater, ICP analysis showed that the Cr removal was 99.8% and other metal ions such as Cu, Ni, Fe, Zn, Cd, Pb, Co and Mn removal were 94.7%, 99.2%, 99.9%, 99.9%, 99.5%, 99.9%, 95.6% and 97.6%, respectively. In case of cyanide wastewater, the metal removal, especially Ni and Zn removal were 96.5 and 95.2% at higher initial concentration. For acid/alkali wastewater, metal ions removing for Cd, Cr and Fe were 99.2%, 99.5% and 99.9%, respectively. Overall, these ligands are useful for metal removal by column method from industrial wastewater especially plating wastewater. 相似文献
13.
富磷污泥生物炭去除水中Pb(Ⅱ)的特性研究 总被引:9,自引:0,他引:9
以城市污水厂富磷剩余污泥为研究对象,考察高温热解制备生物炭吸附剂对水中Pb(Ⅱ)的去除效果.研究表明,随着热解温度升高,制备的生物炭对Pb(Ⅱ)的吸附能力增强;在相同热解温度下,生污泥生物炭对Pb(Ⅱ)的吸附能力比消化污泥生物炭大.采用700℃热解1 h制备生污泥生物炭以研究对Pb(Ⅱ)吸附的影响因素,结果显示:吸附180 min达到吸附平衡;富磷污泥生物炭对Pb(Ⅱ)的去除率随pH增加而升高;生物炭投加量增加,对Pb(Ⅱ)去除率上升,而单位吸附容量迅速减小.污泥生物炭对Pb(Ⅱ)的吸附符合准二级反应动力学,Langmuir模型比Freundlich模型能更好地拟合等温吸附线.在pH 5.0、吸附时间3 h、生物炭投加量20 g.L-1条件下,对Pb(Ⅱ)的最大吸附量为34.5 mg.g-1,表明富磷污泥生物炭可以作为一种廉价的吸附剂. 相似文献
14.
Soon-An Ong Eiichi Toorisaka Makoto Hirata Tadashi Hano 《Environmental Chemistry Letters》2007,5(2):95-99
We studied the feasibility of using biological granular activated carbon-packed column in treating methylene blue-containing
wastewater. The granular activated carbon with immobilized microbes was packed into a column and fed with 3 liter methylene
blue-containing wastewater daily. With initial 1350 mg/l of methylene blue and 1550 mg/l of chemical oxygen demand, it was
observed that the colour and chemical oxygen demand removal efficiencies were 99 and 78%, respectively. The high treatment
performance of the system could be due to the simultaneous adsorption and biodegradation processes and advantages of immobilized
microbes compare to suspended cell system. 相似文献
15.
The heavy metal ions Zn(II), Pb(II), Cr(III) and Hg(II) were examined in regard of their adsorption behaviour towards Kaolin W from Lohrheim (51% illite, 31% kaolinite and 18% quarz). By means of the Langmuir and Freundlich models the determined adsorption isothermes could be linearized. The ability of glycine and histidine solutions to release heavy metal ions, pre-adsorbed on Kaolin W (36,1–2300 mg kg?1 Zn, Pb, Cr and Hg), was specified. It was found a low influence of glycine, but an evident influence of histidine to the metal release, expecially of Pb and Cr, depending on the metalcoating, metal-amino acid-ratio, experimental pH and testing period. The highest remobilisation fraction, up to 98%, could be found in the case of Zn. This elucidates an enhancement of the zinc release compared with the blank solution, without containing amino acids, to a factor of maximal 9,3. As far as Pb and Cr were concerned the histidine extraction exeeded the remobilisation in the blank solution by a maximum of 50,8 or 40. As Hg develops strong covalent bondings to illite by OH-bridges, the release of Hg was not affected by the amino acids. 相似文献
16.
This study evaluated the feasibility of integrating amorphous magnesite and bentonite clay (composite) as an alternative technology for removing arsenic from industrial effluents. The removal of arsenic from industrial effluents by using magnesite–bentonite clay composite was carried out in batch mode. The effects of equilibration time, adsorbent dosage, adsorbate concentration, and pH on removal of arsenic were investigated. The experiments demonstrated that ≈100% arsenic removal is optimum at 30 minutes of agitation, 2 g of adsorbent dosage (2 g: 100 mL, S/L ratio), and 20 mg L?1 of arsenic concentration. The adsorption data fitted well to both Langmuir and Freundlich adsorption models, hence proving monolayer and multilayer adsorption. The kinetic studies revealed that the data fitted better to a pseudo-second-order reaction than to a pseudo-first-order reaction, hence proving chemisorption. At optimized conditions, the composite was able to remove arsenic to below World Health Organization water quality guidelines, hence depicting that the composite is effective and efficient in removing arsenic from contaminated water. Based on that, this comparative study proves that the composite is a promising adsorbent with high adsorption capacity for arsenic and can be a suitable substitute for the conventional treatment methods. 相似文献
17.
Huan Xi Fanlu Min Zhanhu Yao Jianfeng Zhang 《Frontiers of Environmental Science & Engineering》2023,17(6):71
18.
The adsorption of lead and copper from aqueous solution on modified peat-resin particles 总被引:5,自引:0,他引:5
Raw peat was modified with sulfuric acid, then mixed modified with resin to prepare the modified peat-resin particles. Using the batch experimental systems, the removal of heavy metals (copper and lead) on the modified peat-resin particles was investigated. The data of the adsorption isotherm could be fitted by the Langmuir equation well. The adsorption rate of heavy metals on modified peat-resin particles was very swift. The removal processes of heavy metals on modified peat-resin particles could be well described by pseudo-second order model. The adsorption rate of lead was affected by the initial heavy metal concentration, initial pH, particle size, agitation speed and particle mass. In the adsorption of heavy metals (lead and copper) on the modified peat-resin particles, ion exchange was the major reaction mechanism. Desorption data showed that the lead adsorbed by modified peat-resin particle could be desorbed by 0.5 N or 1.0 N HNO3. The desorption rate was swift. The experiments indicated that the modified peat-resin particles have great potential for the removal of heavy metals from wastewater. 相似文献
19.
Xinyou Mao Lan Wang Chuanyi Wang Eric Lichtfouse 《Environmental Chemistry Letters》2018,16(4):1429-1434
Minamata disease is caused by methylmercury, which is produced by microorganisms from inorganic mercury ions, Hg(II), in the aquatic environment. Adsorption is a feasible method to remove Hg(II) from waters, but there are some drawbacks when using conventional adsorbents, for example, tedious solid–liquid separation, slow response, and excessive residual levels of mercury. In this work, a novel spongy adsorbent has been developed for Hg(II) removal via surface functionalization of melamine formaldehyde sponge by glutathione. This material mimics a natural antidote that removes trace heavy metals in the human body. Results show that the functionalized sponge displays a 99.99% removal efficiency for low concentrations of Hg(II) of 10 mg/L. As a consequence, the residual Hg concentration is lower than 0.005 mg/L, which is slightly below the standard for total mercury in drinking water, of 0.006 mg/L, formulated by the World Health Organization, and much lower that the discharge regulation standard, of 0.01 mg/L, set by the ministry of environmental protection of China. Adsorption kinetic studies indicate that the functionalized sponge has a fast response. Indeed, the adsorption equilibrium can be reached within 10 min, and about 80% of total adsorption capacities are reached in 1 min. Moreover, the maximum adsorption capacity of the glutathione-functionalized sponge is as high as 240.02 mg/g, as shown by adsorption isotherm. Overall our findings disclose the great potential of the developed sponge adsorbent for rapid and efficient removal of Hg(II) from water. 相似文献
20.
Adsorption of toluene, ethylbenzene and xylene isomers on multi-walled carbon nanotubes oxidized by different concentration of NaOCl 总被引:2,自引:1,他引:1
Multi-walled carbon nanotubes (MWCNTs) were fabricated and oxidized by different concentrations of sodium hypochlorite (NaOCl) solutions. The untreated MWCNTs and modified MWCNTs were employed as adsorbents to study their characterizations and adsorption performance of toluene, ethylbenzene and xylene isomers (TEX) in an aqueous solution. The physicochemical properties of MWCNTs were greatly affected after oxidation, which influences TEX adsorption capacity. The 3% NaOCl-oxidized MWCNTs shows the greatest enhancement in TEX adsorption, followed by the 30% NaOCl. More interestingly, the 15% NaOCl-oxidized MWCNTs has lower adsorption capacities than untreated MWCNTs. The adsorption mechanism of TEX on treated MWCNTs is attributed to the combined action of hydrophobic interaction, π-π bonding interaction between the aromatic ring of TEX and the oxygen-containing functional groups of MWCNTs and electrostatic interaction. 3% NaOCl solution could not only introduce much oxygen-containing functional groups on MWCNTs, but also lead to less damage for the pore structure. This suggests that the CNTs-3% NaOCl is efficient adsorbent for TEX and that they may possess good potential for TEX removal in wastewater treatment. 相似文献