Removal of Metal Ions From Wastewater With Roadside Tree Leaves

This paper reports on research related to the removal of heavy metal ions, such as lead, nickel, and zinc from wastewater by using tree leaves. Twelve different kinds of tree leaves were tested at room temperature. The experiments were carried out with 2 g of 40-50 mesh leaves in 200 mL synthetic wastewater containing about 50 mg/L metal ions. The initial pH of the synthetic wastewater was about 5. The experiments showed that the highest removal rates were 96% for lead (Pb ++ ), 61.7% for nickel (Ni ++ ), and 71.3% for zinc (Zn ++ ), compared with 93.9% for lead, 68.5% for nickel, and 72.1% for zinc achieved by activated carbon. Tree leaves appear to beagoodadsorbent for metal ion removal from wastewater.     

Evaluation of the Efficiency of a Combined Adsorption–Ultrafiltration System for the Removal of Heavy Metals,Color, and Organic Matter from Textile Wastewater

In this work an ultrafiltration (UF) membrane system was investigated for the treatment of textile wastewater. UF membranes were assisted by activated sludge and minerals, which were employed as sorbents, to remove Cu(II), Pb(II), Zn(II), Ni(II), color, and organics. Significant variations were observed in metal removal efficiencies among the textile wastewater samples of different origin, even at the same pH (= 6) due to the presence of different compounds in wastewater. At the examined pH range (5.63–9.21), the dominant mechanism for copper and lead removal was the formation of insoluble metals due to precipitation and complexation of metal ions with wastewater compounds, including adsorption of metals on suspended solids and colloidal matter. The adsorption process of metals on minerals and activated sludge was the dominant process for nickel and zinc removal at low pH, while precipitation/complexation prevailed at higher pH. The examined adsorption-UF system could produce a treated effluent having low metal concentrations that could be safely discharged into municipal sewers. COD removal ranged from 76%–92% for the five textile wastewater samples. The color removal accomplished was significant (45%–70%), and depended on the type of dye.     

Treatment of wastewater containing copper,zinc, nickel and cobalt using Duolite ES‐467

Duolite ES‐467 was used to treat wastewater containing heavy metal ions. Sorption experiments were carried out at varying pH values, agitation speeds, reaction times, and metal ion and sorbent concentrations. Each of the parameters affects the sorption behaviour of individual metal ions. Copper sorption was greater compared with other metal ions such as zinc, nickel and cobalt. The presence of other metal ions affects copper sorption. Equilibrium isotherm curves were developed. These were used to predict that the metal ion concentration would be reduced from 100 to less than 1 mg dm^?3. Fixed bed tests were conducted to investigate the efficiency of Duolite ES‐467 for the selective removal of copper ions from multi‐metal solutions. Breakthrough curves were obtained using Duolite ES‐467 for solutions containing copper, nickel and copper, zinc, nickel and cobalt. Elution studies were also carried out using sulfuric acid. © 2002 Society of Chemical Industry     

丙烯酰胺-丙烯酸-丙烯羟肟酸共聚物乳液脱除电镀废水中的重金属离子

采用反相乳液聚合法合成了丙烯酰胺(AM)-丙烯酸(AA)- 丙烯羟肟酸(AHA)共聚物乳液。考察了该共聚物配方中丙烯羟肟酸用量、共聚物乳液的投量和pH值对电镀废水中重金属离子的脱除效果。结果表明：pH=10,丙烯羟肟酸在共聚物乳液中的用量≥15%,共聚物乳液的投量为20～30 mg/L时,脱除电镀废水中重金属离子的效果最好,Cr、Cu、Ni和Zn等重金属离子的脱去率≥99.5%,处理后的水中每种重金属离子浓度≤0.2 mg/L。     

Application of iron-coated zeolites (ICZ) for mine drainage treatment

To evaluate iron-coated zeolite (ICZ) for the treatment of mine drainage contaminated arsenic (As), cadmium (Cd) and lead (Pb), a full scale treatment system was installed and operated for nine months. Because it is well known that ICZ can remove As from the water stream, the removal characteristics of cationic metal ions (Cd(II), Cu(II), and Pb(II)) using ICZ were investigated by batch and column experiments before the field test. In the batch test, over 99% of the heavy metal ions were removed by the ICZ within 30 min. The results for the adsorption kinetics and adsorption isotherms were fitted well by a pseudo-second-order model and the Langmuir equation, respectively. An affinity analysis showed that the adsorption of heavy metal ions onto ICZ was favorable. In the column experiments, the cadmium breakthrough point was about 50 bed volumes, while the copper breakthrough occurred immediately in the zeolite column. The lead was not detected in any of the columns in the experiments. In the field experiment, the removal efficiency of arsenic onto ICZ was approximately 99% and the removal of heavy metals onto ICZ field-scale experiments was quite lower compared to the results of laboratory experiments. The value of pH in influent and effluent was about 7.0. Based on the results, ICZ is a suitable material to treat the mine drainage or wastewater bearing As(V) and slightly higher concentration of heavy metals simultaneously.     

Removal of Heavy Metals from a Chelated Solution with Electrolytic Foam Separation

Abstract

An experimental study was conducted on the chelation and electrolytic foam separation of trace amounts of copper, nickel, zinc, and cadmium from a synthetic chelated metal wastewater. Sodium ethylenediaminetetraacetate (EDTA), citrate, sodium diethyldithiocarbamate (NDDTC), and potassium ethyl xanthate (KEtX) were used with sodium dodecylsulfate (NaDS) as a foam-producing agent. Experimental results from an electrolytic foam separation process showed that chelating agents NDDTC and KEtX, due to their higher chelating strength and hydrophobic property, can efficiently separate Cu and Ni from chelated compounds (Cu, Ni/EDTA, and Cu, Ni/citrate). In a Cu-EDTA-NDDTC system with a chelating agent/metal ratio of 4, the residual Cu(II) concentration is 0.7 mg/L. The effects of chelating agent types and different chelating agents concentrations on the removal of metal ions were studied. The effect of NaDS dosage on flotation behavior and the efficiency of metal removal were also investigated.     

高分子重金属絮凝剂对镍离子螯合能力的研究

研究了高分子重金属絮凝剂(PEX)对镍离子螯合能力的大小,以含镍水样作为处理对象,通过一系列试验证明:PEX对镍离子的螯合能力强,生成的螯合体溶解度小,对低浓度的镍离子废水处理效果好。废水中一定量的EDTA或Ca2+的存在,不仅不会影响PEX对镍离子的去除,而且会大大促进这一过程。     

铁氧体法去除废水中的镍、铬、锌、铜离子

采用铁氧体法处理含镍、铬、锌、铜的废水,研究了pH及硫酸亚铁投加量对重金属离子去除效果的影响.对于镍、锌、铜离子,最佳絮凝pH分别为8.00～9.80、8.00～10.50和10.00,投加的亚铁离子与其摩尔比均为2～8;六价铬的最佳还原pH为4.00～5.50,最佳絮凝pH则为8.00～10.50,最佳投料比为20....     

Combined Adsorption and Ultrafiltration Processes Employed for the Removal of Pollutants from Metal Plating Wastewater

This work investigated the use of combined sorption and ultrafiltration (UF) processes for the treatment of electroplating wastewater. The combined vermiculite – UF and bentonite – UF treatment schemes were assessed for their ability to remove nickel, zinc, organic, matter, and color. UF significantly reduced nickel and zinc concentration from wastewater at alkaline environment with removal efficiencies higher than 89% at pH ≥ 8 for both metals. Mineral addition increased metal removal efficiency to higher values (> 97% at pH ≥ 8). The presence of organic compounds and cations in wastewater limited the adsorption efficiency of minerals. Binary metal solutions suppressed the adsorption process for both nickel and zinc. The adsorption of metals on minerals was a multi-stage process where intraparticle diffusion was not the only rate limiting step. Isotherm examination showed that the best fit to the experimental data was obtained by the Langmuir model, and the three parameter models of Redlich-Peterson, Toth, and Sips converged to the Langmuir model. UF combined with minerals resulted in significant removal of organics and color. Furthermore, UF of wastewater resulted in limited membrane fouling.     

Crossflow Surfactant-Based Ultrafiltration of Heavy Metals from Waste Streams

Abstract

Five heavy metals (cadmium, lead, copper, nickel, and zinc) in a simulated wastewater, alone and together, were substantially removed by surfactant-based ultrafiltration using natural surfactants such as a derivative of cholesterol (deoxycholic acid) and lecithins. Selective and total removal of metal ions has been achieved by applying an appropriate level of surfactant-to-metal ratio (S/M). The underlying principle is to increase the size of the target metal ions by fixing them to larger surfactant macromolecules so they can be retained by a compatible membrane. Deoxycholic acid exhibited more efficiency in metal removal than did lecithin and sodium dodecyl sulfate. This research showed that transmembrane pressure had a minimal effect on metal removal whereas S/M had a substantial influence. The optimal S/M for considerable metal removal (99.9 + rejection ratio) is around 2.5 and 5 for deoxycholic acid and sodium dodecyl sulfate, respectively. The binding of metals to surfactant in the absence of membrane interferences was also determined by a centrifuge method.     

Removal of heavy metals by polysaccharide: a review

ABSTRACT

Industries produce large amounts of heavy metal waste that are hazardous to the environment. Thus, heavy metal ions such as nickel (II), lead (II), copper (II), cadmium (II), and zinc (II), must be removed from wastewater. One commonly employed method is biosorption, which is the adsorption of metal ions by biomaterials such as polysaccharides. In this review, polysaccharides are classified into four groups: polysaccharide homopolymers, polysaccharide blends, copolymers, and polysaccharide composites. Pristine natural polysaccharides like chitin, chitosan, cellulose, starch, and alginate which have multiple functional groups. Additional functionalization is introduced in the form of blending, grafting, or mixing with various nanomaterials having additional functional group to make it more efficient for heavy metal ion adsorption. Introduction of second component onto the main polymer chain not only introduce functionality but enhance mechanical strength which is one of the vital requirements for the recyclability of adsorbent. Longer the time adsorbent is reused more economical is the removal process of metal ions from wastewater. Heavy metal ions undergo various types of interaction like π-π interactions, dipole–dipole interaction, hydrogen bonding or van der walls force with homopolymer, copolymers, blends, or nanocomposite having anions or electron-rich group. Adsorption process is studied by adsorption kinetics and adsorption isotherms. This review represents the adsorption behavior of chitosan, cellulose, starch, alginate, and their derivatives.     

Biosorption of Zinc on Palm Tree Leaves: Equilibrium,Kinetics, and Thermodynamics Studies

Abstract

The efficiency of using palm tree leaves to remove zinc ions from aqueous solution was studied. Adsorption isotherms, kinetics, and thermodynamics studies were conducted. The influence of different experimental parameters, such as equilibrium pH, shaking rate, temperature, and the presence of other pollutants such as chelating agents on the biosorption of zinc on palm tree leaves was investigated.

Batch biosorption experiments showed that palm tree leaves used in this study proved to be suitable for the removal of zinc from dilute solutions where a maximum uptake capacity of 14.7 mg/g was obtained at 25°C. Zinc biosorption on palm tree leaves was found to be highly pH dependent. The biosorption process was found to be rapid with 90% of the adsorption completed in about 10 min. Dynamics studies of the biosorption of zinc on palm tree leaves showed that the biosorption process followed the pseudo second‐order kinetics with little intraparticle diffusion mechanism contribution. The equilibrium results indicated that zinc biosorption on palm tree leaves could be described by the Langmuir, Freundlich, Gin et al., and Sips models. Using the Langmuir equilibrium constants obtained at different temperatures, the thermodynamics properties of the biosorption (ΔG⁰, ΔH⁰, and ΔS⁰) were also determined. The values of these parameters indicated the spontaneous and endothermic nature of zinc biosorption on palm tree leaves.     

Factorial experimental design for biosorption of iron and zinc using Typha domingensis phytomass

Typha domingensis phytomass was used as a biosorbent for metal ions removal from wastewater. A full 2³ factorial design of experiments was used to obtain the best conditions of biosorption of Fe³⁺ and Zn²⁺ from water solutions. The three factors considered were temperature, pH, and biosorbent dosage. Two levels for each factor were used; pH (2.5 and 6.0), temperature (25 and 45 °C), and phytomass loading weight (0.5 and 1 g/50 ml). Batch experiments were carried out using 50 ml solutions containing 10 mg/l Fe³⁺ and 4 mg/l Zn²⁺ simulating the concentration of those metals in a real wastewater effluent. The removal percentages of iron and zinc after 120 min of contact time were then evaluated. The results were analyzed statistically using the Minitab 15 statistical software to determine the most important factors affecting the metals removal efficiency. The pH was found to be the most significant factor for the two studied metal ions.     

含铜/铬电镀废水的处理与分离研究

电镀废水中含有铬铜锌镍等金属离子,其中铬存在的形式有C r（Ⅲ）和C r（Ⅵ）两种,C r（Ⅵ）的毒性最大。本文介绍了以N a2CO3为沉淀剂,去除电镀废水中除C r（Ⅵ）以外的金属离子,在碱性条件下将滤渣用双氧水氧化,将C r（Ⅲ）氧化为C r（Ⅵ）,向滤液中加入硝酸铅沉淀C r（Ⅵ）离子,再以N aOH为沉淀剂去除电镀废液中铜镍锌三种金属离子,使净化后的电镀废液达到GB8978-1996中一级排放标准,从而进行达标排放。     

Synthesis and Characterization of Novel Thermoplastic Films for Removal of Heavy Metal Ions

The main objective of this study is to establish the applicability of novel thermoplastic films based on extracted gelatins from bovine (G_b) and bird (G_c) bones in addition to hide powder (HP), which blended with modified polyethylene (MPE) for the removal of heavy metal ions such as copper (II), chromium (VI), nickel (II) and zinc (II) from aqueous media. The chemical reaction between 2-oxoglutaric acid with furfural in presence of methyl amine, via Mannich reaction mechanism, resulted in chemical compound I. The chemical structure of product I was confirmed by different spectroscopic tools such as: nuclear magnetic resonance (¹³C- and ¹H-NMR) and Fourier transform infrared spectroscopy (FT-IR). The synthesized chemical product I was used as compatibilizing agent for blending G_b, G_c and Hp with MPE to obtain thermoplastic films using a polymer melting technique. The efficiency of the prepared films for absorption of different heavy metal ions from aqueous solution was investigated. The results indicated that the compatibilized films (MPE/I/HP) illustrated a maximum removal of zinc metal ions (～100%) under conditions of initial metal concentration about 240 mg/l. While, at initial metal concentration of about 150 mg/l, they exhibited excellent efficiency for removal of mixed metal ions of about 97–100% relative to the uncompatibilized ones (MPE/HP) 0%.     

Poly(hydroxamic acid) ligand from palm-based waste materials for removal of heavy metals from electroplating wastewater

Heavy metals pollutants are nonbiodegradable and their bioaccumulation results in detrimental environmental consequences. Therefore, it is important to effectively remove toxic heavy metal waste from industrial sewage. Thus, the main goal of this research is to synthesize an ideal cellulose-based adsorbent from palm-based waste materials (agro waste) in order to be utilized in real-life practical applications with low cost as such removing common toxic heavy metals from industrial effluents. A poly(methyl acrylate) grafted palm cellulose was synthesized via a free-radical initiation process, followed by an oximation reaction to yield poly(hydroxamic acid) ligands. The adsorption capacity (q_e) of poly(hydroxamic acid) ligands for metal ions such as copper (Cu²⁺), iron (Fe³⁺), and lead (Pb²⁺) were 325, 220, and 300 mg g⁻¹, respectively at pH 6. In addition, the X-ray photoelectron spectrometry results are to be proved the binding of metal ions, for instance, Cu(II) ions showed typically significant BEs of 932.7 and 952.0 eV corresponding to the Cu2p3/2 and Cu2p1/2 species. The heavy metal ions adsorption followed a pseudo-first-order kinetic model pathway. The adsorption capacity (q_m) is also derived from the Langmuir isotherm linear plot, which does not showed good correction coefficients. However, the results were correlated to the Freundlich isotherm model, where the R² value showed significance (>0.98), indicating that multiple layer adsorption occurs on the synthesized ligand. The synthesized polymeric ligand is an excellent adsorbent for the removal of heavy metals from the industrial wastewater. In addition, the metal analysis results showed that about 98% removal of copper and iron ions from electroplating wastewater including lead, nickel, and chromium can be removed up to 85–97%.     

The use of exhausted olive cake ash (EOCA) as a low cost adsorbent for the removal of toxic metal ions from aqueous solutions

The removal characteristics of cadmium (Cd(II)) and nickel (Ni(II)) ions from aqueous solution by exhausted olive cake ash (EOCA) were investigated under various conditions of contact time, pH, initial metal concentration and temperature. Batch kinetic studies showed that an equilibrium time of 2 h was required for the adsorption of Ni(II) and Cd(II) onto EOCA. Equilibrium adsorption is affected by the initial pH (pH₀) of the solution. The pH₀ 6.0 is found to be the optimum for the individual removal of Cd(II) and Ni(II) ions by EOCA. The adsorption test of applying EOCA into synthetic wastewater revealed that the adsorption data of this material for nickel and cadmium ions were better fitted to the Langmuir isotherm since the correlation coefficients for the Langmuir isotherm were higher than that for the Freundlich isotherm. The estimated maximum capacities of nickel and cadmium ions adsorbed by EOCA were 8.38 and 7.32 mg g⁻¹, respectively. The thermodynamic parameters for the adsorption process data were evaluated using Langmuir isotherm. The free energy change (ΔG°) and the enthalpy change (ΔH°) showed that the process was feasible and endothermic respectively. As the exhausted olive cake is discarded as waste from olive processing, the adsorbent derived from this material is expected to be an economical product for metal ion remediation from water and wastewater.     

Removal of Lead and Nickel Ions Using Zeolite Tuff

The capacity of Jordanian zeolite tuff for the removal of lead and nickel ions from aqueous solutions has been investigated under different conditions, namely zeolite particle size, initial solution pH, initial metal ion concentration, slurry concentration and solution temperature. Equilibrium data obtained have been found to fit both the Langmuir and Freundlich adsorption isotherms. It has been found that this zeolite (phillipsite) tuff is an efficient ion exchanger for removing both lead and nickel ions. Its removal capability is considerably higher for lead ions than for nickel ions under all conditions tested; however, the actual exchange capacities are far below the theoretical values. The finer the zeolite particles used, the higher the metal exchange capacity. An initial solution pH of 4·0 is favourable for obtaining high metal removal. © 1997 SCI.     

Binding of metal cations by natural substances

The binding of mercuric chloride and other metal salts to bark, activated sludge (Milorganite), chitosan, poly(p-aminostyrene), and other natural and synthetic materials was investigated by specific atomic absorption and x-ray fluorescence spectroscopy. The synthetic poly(aminostyrene) was included for comparison with the natural polyamine chitosan. Our results show that a wide range of natural materials are potentially useful for the removal of toxic and precious metals that may be present in industrial effluents, mine waters, or other water supply. Such metal salts include those of mercury, lead, zinc, cadmium, copper, nickel, cobalt, iron, manganese, silver, platinum, palladium, and gold.     

Sorptive removal and recovery of nickel(II) from an actual effluent of electroplating industry: Comparison between <Emphasis Type="Italic">Escherichia coli</Emphasis> biosorbent and Amberlite ion exchange resin

The removal and recovery of nickel(II) from wastewater of an electroplating factory was investigated using the waste Escherichia coli biomass as the biosorbent. The results were compared with those from using Amberlite IRN-150 as a commercial sorbent resin. The resin showed better performance with a q _max value of 30.48 mg/g compared to 26.45 mg/g for the biomass, as predicted by the Langmuir isotherm model. Kinetic experiments revealed that the biosorption equilibrium was attained within 15 min. In the recycling of the sorbents, the desorption of nickel(II) from Amberlite was only 50%, which is too low for the adsorption performance of the resin to be maintained at an economic level in subsequent cycles. In contrast, the biomass exhibited reasonable adsorption-desorption performance over three repeated cycles. The capability for repeated use of the sorbent over several cycles and for recovery of the metal ions is the main advantage of the waste biomass.