Monitoring the Physicochemical and Chemical Treatment of Textile Wastewater using GC/MS,LC/MS and ‐MS/MS Techniques

Abstract

Conventional biological wastewater treatment processes often fail in the elimination of finishing agents contained in textile wastewater such as dyes, surfactants, and softeners. Therefore, discharges from the textile industry are known as a major source of water pollution reaching groundwater and even drinking water treatment. Physicochemical treatment and advanced treatment processes (AOP) were applied to eliminate the pollutants prior to discharge. Ozone (O₃), O₃/UV, hydrogen peroxide/UV (H₂O₂/UV), Fenton's reagent (Fe²⁺/H₂O₂) were applied to eliminate by oxidation while ultrasonication (US) alone, US/UV or powdered activated carbon (PAC) were used for the physicochemical treatment. Elimination was monitored by a conventional sum parameter analyses (COD, BOD, DOC) while gas chromatography/mass spectrometry (GC/MS) and liquid chromatography coupled with MS and tandem mass spectrometry (LC/MS and ‐MS/MS) was applied for follow‐up of pollutants and their degradation products. The application of PAC, Fenton, and O₃/UV resulted in the highest dissolved organic carbon elimination. A complete or partial elimination and/or degradation of non‐polar or polar pollutants was observed by GC/MS or flow injection analysis/MS (FIA/MS) respectively. LC/MS and MS/MS analyses confirmed that ethoxylated surfactants (AEO) present in the original wastewater could be oxidized or destroyed resulting in carboxylated AEO and polyethylene glycol (PEG) or even carboxylated PEG.     

Fixed‐bed column study of the removal of anions and heavy metals from cotton textile waste water by using polyaniline and its nanocomposite containing nanometer‐size Fe3O4

Preparation of polyaniline (PAn) and its nanocomposite containing nanometer‐size Fe₃O₄ is discussed, and their capability of separating anions and heavy metals from cotton textile industry waste water is studied. The removal of anions and heavy metals from the waste water was investigated and compared when PAn, nanometer‐size Fe₃O₄, and PAn/Fe₃O₄ nanocomposite were used. The results indicated that PAn and its composite were able to remove the anions and heavy metals. The anion and heavy metal removal percentages were increased by using PAn and nanometer‐size Fe₃O₄. The morphology and chemical structure of the adsorbents were investigated by scanning electron microscopy and Fourier transform infrared spectroscopy. J. VINYL ADDIT. TECHNOL., 2010. © 2010 Society of Plastics Engineers     

Effect of sonication assisted by titanium dioxide and ferrous ions on polyaromatic hydrocarbons (PAHs) and toxicity removals from a petrochemical industry wastewater in Turkey

BACKGROUND: In Izmir (Turkey) polyaromatic hydracarbon (PAH) removal efficiencies are low in petrochemical industry aerobic biological wastewater treatment plants because bacteria are not able to overcome the inhibition of these toxic and refractory organics. In order to increase PAHs removal, sonication process was chosen among other advanced treatment processes include sonication processes. The effects of ambient conditions, increasing sonication time, sonication temperature, TiO₂ and Fe⁺² concentrations on sonication at a petrochemical industry wastewater treatment plant in Izmir (Turkey) was investigated in a 650 W sonicator, at a frequency of 35 kHz and a 500 mL glass reactor. RESULTS: Increasing the temperature improved PAH removal after 150 min sonication at 30 °C and 60 °C. The maximum total PAH removal efficiencies were the same in a reactor containing 20 mg L^?1 TiO₂ and in a TiO₂‐free reactor at 30 °C and 60 °C after 150 min sonication. Maximum 91% and 97% total PAH removals were obtained in a control reactor and a reactor containing 20 mg L^?1 Fe⁺² at 30 °C and 60 °C, respectively, after 150 min sonication. The PAH concentration was toxic to Daphnia magna, so that the EC₅₀ value decreased significantly from 342.56 ng mL^?1 to EC₅₀ = 9.88 ng mL^?1 and to EC₅₀ = 3.35 ng mL^?1, at the lowest TiO₂ (0.1 mg L^?1) and Fe⁺² (2 mg L^?1) concentrations, respectively, after 150 min sonication at 30 °C. CONCLUSION: PAHs and the acute toxicity in a petrochemical industry wastewater were removed efficiently through sonication. Copyright © 2010 Society of Chemical Industry     

Recent studies in adsorption of Pb(II), Zn(II) and Co(II) using conventional and modified materials:a review

ABSTRACT

Heavy metal contamination and its detrimental effects on human health and environment have been a worldwide concern. Over the years, various technologies have been adapted to tackle this problem. Adsorption is still considered to be one of the most feasible and cost-effective methods for treating wastewater contaminated with heavy metals. Adsorbents such as activated carbon, clay, zeolites and silica have been studied extensively in the past. Modification of these conventional adsorbents and the synthesis of nonconventional adsorbents such as nanocomposites and metal organic frameworks (MOF’s) have been the main focus of study in recent times. This review article attempts to present a detailed account of various adsorbents and their removal efficiencies for the treatment of wastewater contaminated with lead(II), zinc(II) and cobalt(II) in the current decade. Influence of various parameters, adsorption isotherms and kinetics best described for their removal have also been reviewed in detail. It is observed that most of the adsorbents followed pseudo second order kinetics suggestive of a chemisorption process. After conducting a thorough review of more than 120 recently published papers, it can be inferred that nanomaterials and nanocomposites have shown excellent adsorption capacity for removal of these heavy metals.     

Control of the Fenton process for textile wastewater treatment using artificial neural networks

BACKGROUND: The Fenton process is a popular advanced oxidation process (AOP) for treating textile wastewater. However, high consumption of chemical reagents and high production of sludge are typical problems when using this process and in addition, textile wastewater has wide‐ranging characteristics. Therefore, dynamically regulating the Fenton process is critical to reducing operation costs and enhancing process performance. The artificial neural network (ANN) model has been adopted extensively to optimize wastewater treatment. This study presents a novel Fenton process control strategy using ANN models and oxygen reduction potential (ORP) monitoring to treat two synthetic textile wastewaters containing two common dyes. RESULTS: Experimental results indicated that the ANN models can predict precisely the colour and chemical oxygen demand (COD) removal efficiencies for synthetic textile wastewaters with correlation coefficients (R²) of 0.91–0.99. The proposed control strategy based on these ANN models effectively controls the Fenton process for various effluent colour targets. For treating the RB49 synthetic wastewater to meet the effluent colour targets of 550 and 1500 ADMI units, the required Fe⁺² doses were 13.0–84.3 and 5.5–34.6 mg L^?1 (Fe⁺²/H₂O₂ = 3.0), resulting in average effluent colour values of 520 and 1494 units. On the other hand, an effluent colour target of 550 ADMI units was achieved for RBB synthetic wastewater. The required Fe⁺² doses were 14.6–128.0 mg L^?1; the average effluent colour values were 520 units. CONCLUSION: The Fenton process for textile wastewater treatment was effectively controlled using a control strategy applying the ANN models and ORP monitoring, giving the benefit of chemical cost savings. Copyright © 2009 Society of Chemical Industry     

Facile fabrication of highly efficient bifunctional polydopamine–polyethyleneimine copolymerization-modified magnetic material and its effective applications for both adsorption of gold ions and catalytic reduction of 4-nitrophenol

The heavy metal ions and organic pollutants are major harmful substances in wastewater because of their toxicity on human health and environment. Nowadays, the adsorption–catalysis treatment to remove them simultaneously is still a challenge because of their different reaction mechanisms. Herein, a novel bifunctional polymer magnetic material Fe₃O₄@PDA-PEI was successfully developed through a facile co-deposition method by the copolymerization modification of polydopamine (PDA) and polyethyleneimine (PEI) on magnetic ferroferric oxide, which can both be utilized for both heavy metal ion removal from simulated industrial wastewater and further effective catalytic reduction of toxic 4-nitrophenol (4-NP) to useful 4-aminophenol. The maximum adsorption capacity of Fe₃O₄@PDA-PEI for gold ions was 465.12 mg/g at 35°C, and the adsorption thermodynamic parameters ΔG, ΔH, and ΔS of Fe₃O₄@PDA-PEI (m(PDA):m(PEI) = 2:1) were −5.28 (35°C), 25.58, and 111.30 J K⁻¹ mol⁻¹, respectively. In addition, a sustainable strategy of converting gold ions to gold nanoparticles has been demonstrated for additional catalytic functionality of Fe₃O₄@PDA-PEI, and Fe₃O₄@PDA-PEI-Au could effectively catalyze the reduction of 4-NP at ambient temperature within 9 min. Fe₃O₄@PDA-PEI with the advantages of facile fabrication, easy separation, excellent adsorption, and catalysis performance could be used as a promising polymer composite material in complicated wastewater environment. © 2023 Wiley Periodicals LLC.     

多羟基结构态亚铁处理含重金属废水的应用

结构态亚铁是一种具有高活性结构的亚铁化合物,具有比表面积大、还原性强等优点,被广泛应用于研究处理重金属废水和有机废水.然而,目前结构态亚铁处理含高浓度重金属的实际工业废水的重金属去除效果、作用条件、处理工艺还缺乏深入探究.文中选取3种具有代表性的实际工业废水,探究结构态亚铁对废水中重金属的去除效果,设计能够满足排放要求...     

Biotechnology group meeting. Biochemistry and genetics for increasing productivities of industrial fermentation

Biosorption of heavy metals by microbial cells has been recognized as a potential alternative to existing technologies for removing heavy metals from industrial waste waters. Many aquatic microorganisms, such as algae, can take up dissolved metals from their surroundings to their cells. In this study, the adsorption of lead(II) ions was investigated in a single-staged batch reactor. Chlorella vulgaris, a green alga, was used as the sorbent. The sorption phenomenon was expressed by the Freundlich adsorption isotherm and this expression was used for the calculation of residual or adsorbed metal ion concentration at equilibrium (C_eq or C_x,eq) at a given ‘volume of waste water containing heavy metal ion/quantity of alga (V₀/X₀)’ ratio in a single-staged batch reactor. Experimental C_eq and C_x,eq values were compared to calculated ones. Applications in waste water treatment for lead(II) removal have been suggested.     

Removal of heavy metals from wastewater by membrane processes: a comparative study

Wastewater containing copper and cadmium can be produced by several industries. The application of both reverse osmosis (RO) and nanofiltration (NF) technologies for the treatment of wastewater containing copper and cadmium ions to reduce fresh water consumption and environmental degradation was investigated. Synthetic wastewater samples containing Cu²⁺ and Cd²⁺ ions at various concentrations were prepared and subjected to treatment by RO and NF in the laboratory. The results showed that high removal efficiency of the heavy metals could be achieved by RO process (98% and 99% for copper and cadmium, respectively). NF, however, was capable of removing more than 90% of the copper ions existing in the feed water. The effectiveness of RO and NF membranes in treating wastewater containing more than one heavy metal was also investigated. The results showed that the RO membrane was capable of treating wastewater with an initial concentration of 500 ppm and reducing the ion concentration to about 3 ppm (99.4% removal), while the average removal efficiency of NF was 97%. The low level of the heavy metals concentration in the permeate implies that water with good quality could be reclaimed for further reuse.     

Effect of Precipitant Additives on the Sludge Settling and Compacting Performance for Heavy Metal Wastewater Treatment

The purpose of this study is to investigate the impact of precipitant additives, i.e., calcium hydroxide (Ca(OH)₂), calcium carbonate (CaCO₃) and recycled sludge (RS), on the settling and compacting performance of sludge formed in the process of heavy metal wastewater treatment using bio-polymer ferric sulfate (BPFS). The results show that CaCO₃ is the most suitable additive since heavy metal removal, sludge settling performance, and compacting performance is improved by 20%, 83.3%, 23.5%, respectively. In addition, scanning electron microscopy and X-ray diffraction were measured for contrasting the sludge morphology and crystallinity. The results suggest that CaCO₃ acted as seeding material produces the largest flocs. Moreover, the flocculation theory combined with zeta potential measurement was used to explain the sludge formation mechanism, which is proposed as charge neutralization by BPFS, sweep flocculation by amorphous precipitate, and bridging flocculation by polyacrylamide (PAM) in sequence. The improvement of sludge properties by adding CaCO₃ benefits from the enhancement of sweep flocculation. In summary, the interaction mechanism between precipitant additives and sludge performance is well understood, thus providing useful information about adding precipitant additives to improve both the sludge settling properties and the quality of the treated water during the heavy metal wastewater treatment.     

Retention of Pb(II) by a Low-Cost Magnetic Composite Prepared by Environmentally-Friendly Plasma Technique

A low-cost magnetic composite (gelatin/Fe₃O₄) is prepared by Fe₃O₄ nanoparticles treated with gelatin using an environmentally-friendly plasma technique, and is applied for the removal of toxic Pb(II) ions from aqueous solutions. Not only that it originates from cheap and abundant raw materials, the gelatin/Fe₃O₄ composite also has advantages in convenient magnetic separation from aqueous solution, which can hopefully reduce water treatment expenses. The batch experimenta results indicate that the maximum adsorption capacity (q_max) of Pb(II) on this gelatin/Fe₃O₄ composite is ～115 mg/g, higher than most of the other bare and modified magnetic materials, which is considered to be attributed to the strong interaction between Pb(II) and the abundant functional groups introduced by gelatin. When exposed to acidic solutions, the dissolution of the gelatin/Fe₃O₄ nanoparticles is minimal due to the protective character of the grafted gelatin layer on the Fe₃O₄ nanoparticles. The utilization of the plasma technique in the synthesis of magnetic composite agrees well with the tenet of green chemistry. It is promising that this gelatin/Fe₃O₄ composite would become an efficient and economic material for heavy metal ion removal in the practical environmental remediation.     

Removal of Arsenic from Wastewaters by Airlift Electrocoagulation: Part 3: Copper Smelter Wastewater Treatment

The arsenic content in wastewater is of major concern for copper smelters. A typical complex wastewater treatment is needed with a combination of chemical and physical processes. Electrocoagulation (EC) has shown its potential for arsenic removal due to the formation of ferric hydroxide-arsenate precipitates. This work evaluates the feasibility of EC as a treatment process at various stages during conventional copper smelter wastewater treatment – with a focus on arsenic. The reactor used is a batch airlift electrocoagulator. The results showed that raw copper smelter wastewater was difficult to treat for arsenic and heavy metals with EC, mainly due to the very low pH. On the other hand, after a preliminary Ca(OH)₂ treatment for sulphate and heavy metal removal, arsenic could be removed totally by EC. In addition, EC could also be applied as a final remediation control tool for arsenic since the national threshold value for wastewater discharge could rapidly be reached when the conventional method did not clean the wastewater sufficiently.     

Rapid Adsorption of Heavy Metals by Fe3O4/Talc Nanocomposite and Optimization Study Using Response Surface Methodology

Fe₃O₄/talc nanocomposite was used for removal of Cu(II), Ni(II), and Pb(II) ions from aqueous solutions. Experiments were designed by response surface methodology (RSM) and a quadratic model was used to predict the variables. The adsorption parameters such as adsorbent dosage, removal time, and initial ion concentration were used as the independent variables and their effects on heavy metal ion removal were investigated. Analysis of variance was incorporated to judge the adequacy of the models. Optimal conditions with initial heavy metal ion concentration of 100, 92 and 270 mg/L, 120 s of removal time and 0.12 g of adsorbent amount resulted in 72.15%, 50.23%, and 91.35% removal efficiency for Cu(II), Ni(II), and Pb(II), respectively. The predictions of the model were in good agreement with experimental results and the Fe₃O₄/talc nanocomposite was successfully used to remove heavy metals from aqueous solutions.     

The sonochemical decolorisation of textile azo dye CI Reactive Orange 127

In the present study, Fenton and sono‐Fenton processes were applied to the oxidative decolorisation of synthetic textile wastewater including CI Reactive Orange 127 and polyvinyl alcohol. Process optimisation [pH, ferrous ion (Fe²⁺) and hydrogen peroxide (H₂O₂)], kinetic studies and their comparison were carried out for both of the processes. The sono‐Fenton process was performed by indirect sonication in an ultrasonic water bath, which was operated at a fixed 35‐kHz frequency and 80 W power. The optimum conditions were determined as [Fe²⁺] = 20 mg l^?1, [H₂O₂] = 15 mg l^?1 and pH = 3 for the Fenton process and [Fe²⁺] = 25 mg l^?1, [H₂O₂] = 5 mg l^?1 and pH = 3 for the sono‐Fenton process. The colour removals were 89.9% and 91.8% by the Fenton and sono‐Fenton processes, respectively. The highest decolorisation was achieved by the sono‐Fenton process because of the production of some oxidising agents as a result of sonication. Consequently, ultrasonic irradiation in the sono‐Fenton process slightly increased the colour removal to 91.8%, while decreasing the hydrogen peroxide dosage to one‐third of that of the Fenton process.     

Removal of heavy‐metal ions from aqueous solution with nanochelating resins based on poly(styrene‐alt‐maleic anhydride)

Chelating resins have been considered to be suitable materials for the recovery of heavy metals in water treatments. A chelating resin based on modified poly(styrene‐alt‐maleic anhydride) with 2‐aminopyridine was synthesized. This modified resin was further reacted with 1,2‐diaminoethan or 1,3‐diaminopropane in the presence of ultrasonic irradiation for the preparation of a tridimensional chelating resin on the nanoscale for the recovery of heavy metals from aqueous solutions. The adsorption behavior of Fe²⁺, Cu²⁺, Zn²⁺, and Pb²⁺ ions were investigated by the synthesis of chelating resins at various pH's. The prepared resins showed a good tendency for removing the selected metal ions from aqueous solution, even at acidic pH. Also, the prepared resins were examined for the removal of metal ions from industrial wastewater and were shown to be very efficient at adsorption in the cases of Cu²⁺, Fe²⁺, and Pb²⁺. However; the adsorption of Zn²⁺ was lower than those of the others. The resin was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X‐ray diffraction analysis, and differential scanning calorimetry analysis. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Use of Electrodialysis to Remove Heavy Metals from Water

Abstract

The removal of heavy metals from water by using electrodialysis is discussed. Parameters studied include current efficiency, stack resistance, and osmotic water transfer. Four single-electrolyte systems are investigated: CdCl₂ and CdSO₄ are used as representative heavy metal salts; NaCl and CaCl₂ are studied in order to enhance the understanding of physical electrodialytic processes in general and to provide a basis of comparison. The variables of electrolyte type, electrolyte concentration, pH, temperature, and elapsed time of membrane usage are examined. Results indicate that the purification of cadmium-laden waters can be achieved while maintaining high current efficiencies and reasonable stack resistances. The osmotic water transfers (in units of liter/mole) of the above cadmium salts are small enough to allow a high percentage of a wastewater stream to be reclaimed as purified water. but are higher than the water transfers of NaCl and CaCl₂ due to increased hydration effects.     

Continuous preparation of Fe3O4 nanoparticles combined with surface modification by L-cysteine and their application in heavy metal adsorption

L-cysteine functionalized Fe₃O₄ magnetic nanoparticles (Cys–Fe₃O₄ MNPs) were continuously fabricated by a simple high-gravity reactive precipitation method combined with surface modification through a novel impinging stream-rotating packed bed with the assistance of sonication. The obtained Cys–Fe₃O₄ MNPs was characterized by XRD, TEM, FTIR, TGA and VSM, and further used for the removal of heavy metal ions from aqueous solution. The influence of pH values, contact time and initial metal concentration on the adsorption efficiency were investigated. The results revealed that the adsorption of Pb(II) and Cd(II) were pH dependent process, and the pH 6.0 was found to be optimum condition. Moreover, the adsorption kinetic for Cys–Fe₃O₄ MNPs followed the mechanism of the pseudo-second order kinetic model, and their equilibrium data were fitted with the Langmuir isothermal model well. The maximum adsorption capacities calculated from Langmuir equation were 183.5 and 64.35 mg g⁻¹ for Pb(II) and Cd(II) at pH 6.0, respectively. Furthermore, the adsorption and regeneration experiment showed there was about 10% loss in the adsorption capacity of the as-prepared Cys–Fe₃O₄ MNPs for heavy metal ions after 5 times reuse. All the above results provided a potential method for continuously preparing recyclable adsorbent applied in removing toxic metal ions from wastewater through the technology of process intensification.     

Al2O3/Yttria‐Stabilized Zirconia Hollow‐Fiber Membrane Incorporated with Iron Oxide for Pb(II) Removal

Removal by absorptive ceramic membranes can simultaneously absorb and separate metal ions from water. Alumina/yttria‐stabilized zirconia (Al₂O₃/YSZ) hollow‐fiber membranes, fabricated using phase inversion and sintering process, were deposited with iron oxide by an in‐situ hydrothermal process. The results showed that α‐Fe₂O₃ was produced and incorporated across the membranes. A reduction in flux was recorded with the deposition of α‐Fe₂O_3. However, it improved the adsorption capacity for heavy metal adsorption. The adsorption‐separation test demonstrated that the optimized membrane is able to completely remove Pb(II) ions after two hours.     

Removal of Trace Concentrations of Heavy Metals Using Complexing Ion‐Exchange Resins

Abstract

Oak Ridge National Laboratory is examining potential new technologies for treating radiologically‐contaminated process wastewater. The current treatment facility is aging and is optimized to remove ⁹⁰Sr, but future wastewaters are likely to contain mostly activated metals, such as ⁵¹Cr and ⁶⁴Cu. Other low‐volume wastewaters may contain trace concentrations of Hg and U. Complexing ion‐exchange resins and other specialized sorbents were tested for removing trace concentrations of heavy metals. Short‐term column tests and batch loading tests were conducted using a surrogate wastewater and various sorbents. These tests showed that metal uptake was very rapid, and that good removal and relatively high loadings could be achieved from a very dilute wastewater surrogate. Forager M‐TU (Dynaphore, Inc.) showed the best overall results, removing 91.9% of the Cr, 99.3% of the Cu, >99.7% of the Hg, and >99.9% of the U with a contact time of 120 seconds in a short‐term column test.     

PCB废水处理及回用技术方案设计

针对IT行业中的PCB生产废水中含有大量的重金属离子,从而给环境带来极大的污染,并严重威胁居民的健康的问题,在总结目前工艺处理流程的基础上,提出一种联合废水处理工艺。针对PCB废水中重金属含量多的问题,采用重金属沉淀--过滤的方法对重金属水进行反复清洗;针对废水中的高浓度有机物,采用BAF-A/O工艺-化学除磷的方式,对其中的有机废水进行处理。最后,通过选取经济和技术指标对上述的废水处理工艺进行评价,验证了上述方案的可行性。