Printing Wastewater Research Articles

The effect of mixing speed to adsorption heavy metal Cu2+ and color using kepok banana peel waste

Home industry of screen printing generally disposes wastewater directly into drainage without being processed first. Wastewater from screen printing industry has a high metal content exceeding the quality standards of Minister of Environment Regulation no. 5 of 2014 concerning Waste Water Quality Standards which are being problem for the environment. This study aims to analyze the effect of mixing speed on adsorption of heavy metal Cu2+ (Copper) using adsorbents from the utilization of kepok banana peel waste in batch reactors and mixed using the jartest tool. In the process of making the adsorbent, the kepok banana peel was dried for 2 days and carbonized by using furnace at 400°C for 2 hours to become powder. After the carbonization process, the size was uniformed into 100 mesh and activated using H2SO4 with an immersion process for 24 hours. The adsorbent powder was then used as much as 10 grams in 250 mL of screen printing wastewater with variations in mixing speed (rpm): 100,150,200 and variations in contact time (minutes): 30,60,90. The result showed that the optimum mixing speed is 100 rpm with a time of 60 minutes. The initial concentration of heavy metals Cu2+ of 3.52 mg/L and after the adsorption process it becomes 0.0716 mg/L, that meet the quality standards of 0.8 mg/L.

Treatment of real printing wastewater using electrocoagulation process with titanium and zinc electrodes

Electrocoagulation (EC) has numerous benefits over traditional coagulation. It is noteworthy that most researchers have studied EC using either iron electrodes or aluminum electrodes. The key objective of this study is to investigate the performance of the EC process with zinc and titanium electrodes for treating real printing wastewater through several experimental conditions. Experiments were done through batch systems. The effects of the operating variables, inclusive of varying current densities (CDs), spacing between electrodes, electrolysis time, and varying electrode materials (titanium and zinc) on the efficiency of the removal of different parameters were studied. Oil and grease, total dissolved solids (TDS), and chemical oxygen demand (COD) were among these parameters. The highest removal efficiency for COD after 90 min using a zinc electrode was approximately 50 % attained at 20 mA/cm2. For the titanium electrode, after 90 min, the highest removal efficiency for COD was 46 % attained at 15 mA/cm2. For the removal efficiency of TDS, the zinc electrode performance was better than that of the titanium electrode for every CD. After 90 min, the optimal TDS removal efficiencies were 9 % and 19 % for titanium and zinc electrodes, respectively. The titanium electrode offers the maximum efficiency of removal for oil and grease. The highest efficiencies of removal were attained at a separation distance of 4 cm. At a CD of 15 mA/cm2, the best COD elimination efficiencies using the titanium electrode at the separation distances of 6, 4, and 2 cm were 24 %, 47 %, and 30 %, respectively. At a CD of 15 mA/cm2, the best COD removal efficiencies using the zinc electrode at the separation distances of 6, 4, and 2 cm were 27 %, 41 %, and 38 %, respectively. In both the zinc and titanium electrodes, following the experiments, corrosion occurred in the anodes, which is evidence that the process of treatment took place. The EC performance was observed to be much better than that of conventional coagulation during the treatment of printing wastewater. Zinc and titanium electrodes demonstrated a good capability of removing pollutants when used in the EC process.

Modification of Manila Grass Activated Carbon for Reactive Dye Adsorption from Textile Printing Wastewater

The aim of this research is to focus on the activated carbon modification for the elimination of Novacron Brilliant Red EC-3GL which is a reactive red dye onto Manila Grass carbonaceous as an adsorbent with chemical activation. The Manila grass waste from the football field was obtained to carbonize at 400 °C. Three-types of chemicals, such as sodium chloride (NaCl), potassium hydroxide (KOH), and phosphoric acid (H3PO4) were used to soak for 1 h before pyrolysis at 700 °C for 2 h. The analysis of activated carbon properties and effects of dye adsorption, such as pH of the feed solution, time to adsorb, the amount of adsorbent, concentration and temperature were studied. Langmuir isotherm and Freundlich isotherm were applied to consider the adsorption mechanism. From the analysis, activated carbon with sodium chloride activation was a high surface area of 148.6 m2/g and a low porosity of 25.72 °A. From the experiments were found that pH for adsorption of 2, absorption time 90 minutes, concentrations used in the adsorption of 50 ppm and the adsorption temperature 30 °C were optimum for dye adsorption. The NBR adsorption percentages from aqueous solution and textile printing wastewater were 77.87 and 85.52, respectively. The adsorption mechanisms of activated carbon were consistent with Langmuir isotherm for an aqueous solution and Freundlich for textile printing wastewater.

Rhodamine B Adsorptive Removal and Photocatalytic Degradation on MIL-53-Fe MOF/Magnetic Magnetite/Biochar Composites

MIL-53-Fe metal–organic framework (MOF) was grown using the terephthalic acid linker and FeCl3 into an already prepared, high surface area, magnetic, Douglas fir biochar/Fe3O4 (MBC) adsorbent hybrid. This resulting triphase hybrid, multifunctional, magnetically recoverable, sorptive, photocatalytic and degradative, adsorbent (MOF–MBC) was used both to remove and catalyze the photodegradation of Rhodamine B (Rh B) with or without Cr6+ present. Rh B is a widely used colorant in textile, printing and tanning industries that is also associated with deleterious health effects. Batch aqueous sorption studies were performed at various pHs, Rh B concentrations and temperatures in-order to determine the optimum adsorption pH, kinetics, thermodynamics and sorption capacity. This adsorption followed pseudo-2nd-order kinetics and exhibited a Rh B Langmuir adsorption capacity of ~ 55 mg/g at pH 6, 200 rpm agitation and 25 °C. This MOF–MBC hybrid was characterized by SEM, TEM, EDS, XRD, FT-IR, TGA, BET, Elemental Analysis and XPS. Deethylated and carboxylic compounds were identified as photodegradation intermediates. Electrostatic and π–π stacking interactions are thought to play a significant role in Rh B sorption. Hexavalent chromium (Cr6+) and Rh B often co-exist in tannery and printing waste water. Cr6+ can trigger the photo-degradation of Rh B into CO2 and H2O in the presence of both MIL-53-Fe MOF and MOF–MBC. Hence, adsorbent stripping regeneration can be minimized in real world applications. The biochar phase, aids to disperse the MOF, to minimize particle aggregation, to provide extra stability to the MOF, and serves as secondary adsorption site for heavy metal, oxy anion and organic contaminants. Large biochar particles allow reasonable flow through column beds while supporting other nanophases, which would cause large pressure drops when used alone.

Removal of pollutants in banknote printing wastewater by mesoporous Fe/SiO2 prepared from rice husk pyrolytic residues.

Iron-incorporated silica (Fe/SiO2) with different Fe/Si molar ratio was successfully prepared from rice husk pyrolytic residues (RHR) through alkali pretreatment, co-precipitation, and calcination. Various characterization methods indicated that the Fe/SiO2 samples possessed mesoporous structure with Fe species incorporated into the framework of silica. The obtained materials were applied in the treatment of hazardous banknote printing wastewater, and under the optimal conditions, colored pollutants, humic acid-like and soluble microbial by-product-like organics were removed significantly. It was found that Fe/SiO2 acted as both flocculant and catalyst, and the framework iron species catalyzed the oxidative degradation of refractory organics in the presence of H2O2. A heterogeneous Fenton-like system was formed in the wastewater treatment process.

Oxidative degradation of cyan flexo dye with Heterogeneous Fenton reagent - Fe2(MoO4)3 particle

Heterogeneous Fenton catalyst Fe2(MoO4)3 was prepared and the process efficiency was evaluated for oxidation of water-based Cyan flexo dye in synthetic aqueous solution and printing wastewater. The removal process of printing dye was analyzed by UV/VIS spectrophotometry, while dye mineralization was evaluated by the determination of total organic carbon content and chemical oxygen demand. Four determinants of the heterogeneous Fenton system, including initial dye concentration, iron concentration, pH and hydrogen peroxide concentration were investigated. Statistical method, definitive screening design was applied to generate optimal operational conditions of the four variables, which maximizes the process of dye removal. The initial dye concentration of 20 mgL-1, catalyst dosage of 0.75 mgL-1, pH of 2 and H2O2 concentration of 11 mM were chosen as the best operational conditions, contributing to 82% of the process efficiency. The Fenton process efficiency of 79% was achieved within the treatment of printing wastewater under optimal conditions for a 90 minute reaction time. The maximum COD removal efficiency was 61.1%, while 67% mineralization was achieved. The obtained results confirmed synergistic effect of Fe3+ and MoO4 2? which contributed to high catalytic activity and high heterogeneous Fenton efficiency.

Electrocoagulation/electroflotation of real printing wastewater using copper electrodes: A comparative study with aluminum electrodes

ABSTRACTMost studies investigated electrocoagulation/electroflotation process (EC/EF) using either aluminum or iron electrodes. The main aim of this study is to investigate the performance of EC/EF to treat printing wastewater under various experimental conditions using copper electrodes. The effects of several variables, including different electrode materials (copper and aluminum), different current densities, electrolysis time, and spacing between electrodes on the removal efficiency of various parameters were investigated. The results showed that the maximum removal efficiencies for COD,TDS, and oil and grease were obtained when using a copper electrode. The maximum removal efficiencies were obtained at a gap distance of 4 cm.

Performance of Nanofiltration Membrane for Printing Wastewater Treatment

Almost every manufacturing process is the major origin of wastewater with certain characteristic. Printing facility provides a wide range of waste component that is harmful to the environment and people. Those harmful waste component contains high concentration of heavy metals and dye. This paper presents one of the most promising methods to remove the heavy metals and dyes from a printing wastewater before discharging to the environment. The feasibility of commercially available NF270 membrane to treat both heavy metals and dye was thoroughly investigated. The study was carried out using a cross-flow nanofiltration membrane system at operating pressure and temperature set at 5 bar and 24 ˚C, respectively. Experimental results showed that the permeate flux of NF270 is decreased from 6.2 to 5.0 L/m2.h after 1-h operation. Whilst, the rejection of both iron and zinc ions could be obtained up to 96.9% and 97.8%, respectively. Additionally, almost complete elimination of colour (99.6%) could be achieved using NF270 membrane. Thus, it can be concluded that the commercial NF270 membrane is promising in removing both heavy metal ions and dye from printing wastewater.

APPLICATION OF ELECTRO-COAGULATION FOR TREATMENT OF WASTEWATER FROM PACKAGE PRINTING PROCESS

Printing wastewater is generally considered as hazardous waste whose treatment and disposal are strictly regulated. Although electro-coagulation (EC) process has been successfully applied for the treatment of different types of wastewater, its application for printing wastewater is rarely reported. In this study, EC was applied to treat the printing ink wastewater, taken from a paper packing factory in An Giang Plant Protection Join Stock Company, which was highly colored and contaminated with organic compounds. The treatment process was performed using aluminum electrodes for two hours. Effects of applied voltage (5 - 40 V), pH (5 - 9), electrodes distance (1 - 5 cm), salt concentration in electrolyte solution (0.05 - 0.4 g/L), and the rotational speed of stirring (0 - 400 rpm) on the removal efficiencies of color and COD were investigated. Based on the effects of various factors, optimum condition for the treatment was given. Results showed that the EC process can effectively remove color and COD for 30 min. The effluent quality in terms of color and COD met well National Technical Regulation on Industrial Wastewater (QCVN 40-2011/BTNMT, column B). Finally, a comparison in removal efficiencies between the processes of EC and chemical-coagulation was also presented.

Investigating the influences of electrode material property on degradation behavior of organic wastewaters by iron-carbon micro-electrolysis

The degradation of Sunset Yellow (SY) wastewater was carried out using Fe-C micro-electrolysis process under the optimal conditions: initial pH 6, Fe/C ratio 1:1, Fe/C total mass 500 g·L−1 and the air flow rate 45 L·h−1. Effects of particle size, particle shape and material species of activated carbon (AC) on degradation and chemical oxygen demand (COD) removal efficiencies of SY by the Fe-C micro-electrolysis process were studied. The degradation and COD removal efficiencies of 500 mg·L−1 SY were approximately 99.0% and 77.5% after 90 min treatment with 3–6 mm spherical coal-based AC particles. Additionally, the degradation and COD removal efficiencies of SY maintained over 99.0% and 65.0% after 90 min treatment with any other types of AC. The stability of the Fe-C micro-electrolysis process was preferably and the AC surfaces before used and after used for 20 times were characterized by SEM, XPS, and XRD. In addition, the decomposition and degradation process was determined by UV–Vis analysis of the treated SY wastewaters. In conclusion, the particle size, particle shape and material species of AC indeed have influences on the degradation and COD removal efficiencies of SY by the Fe-C micro-electrolysis process and 3–6 mm coal-based spherical AC was selected as the optimal electrode material. Moreover, the antibiotic and printing wastewaters were selected to investigate the feasibility of degradation of other refractory organic wastewaters by Fe-C micro-electrolysis process.

Photocatalytic decolorization of cationic and anionic dyes over ZnO nanoparticle immobilized on natural Tunisian clay

In the present work we describe a simple and low-cost method for the decolorization of textile dyeing and printing wastewaters, using ZnO as photocatalyst supported on natural Tunisian clay (ZnO/Clay). This composite ZnO/Clay material was synthesized through a sol–gel method. X-ray diffraction (XRD), Nitrogen Physisorption (BET), Infrared Spectroscopy (FTIR), Scanning Electronic Microscopy (SEM) and High-Resolution Transmission Electron Microscopy (HRTEM) linked with Energy Dispersive X-ray (EDX), were performed in order to explain the characteristics of the ZnO/Clay photocatalyst. The XRD patterns, pointing to the presence of ZnO of very small crystal sizes, i.e. highly dispersed on the clay surface. The photocatalytic activity of ZnO/Clay was assayed in the decolorization of a cationic dye (Malachite Green, MG) and anionic dyes (Red Congo, RC) in aqueous solution as models pollutants under UV irradiation. In addition, the effects of different parameters such as pH of the solution, catalyst dosage, concentration of the dyes, irradiation source, as well as the influence of the presence of inorganic ions were investigated. The ZnO/Clay photocatalyst exhibited high photocatalytic activity of MG and CR decolorization under simulated solar compared to UV irradiation. The recyclability of the ZnO/Clay photocatalyst was as well validated.

Application of a full-scale electrocatalytic reactor as real batik printing wastewater treatment by indirect oxidation process

Batik printing wastewater is mainly characterized by toxic dyes; hence an effective treatment technology with simple operation is needed as a suitable solution. Electrochemical-based advanced oxidation process is a simple and easy method to degrade dyes without generating any harmful sludge as by-products. A full-scale electrocatalytic reactor was constructed as a sub-set of 6 tubes (1.2m3) to treat actual batik printing wastewater; Ti/RuIrO2 electrode is designated as anode and stainless steel plate as cathode. The electrodes were positioned vertically with electrode gap of 30mm and evenly installed inside the tubes. Surface-area-to-volume ratio (S/V) was 6.28m−1. Each tube was equipped with single motor mixer using a fan belt. Optimum operational parameters were investigated, i.e., hydraulic retention time (30, 60, 90, 120, 150 and 180min), electrolyte (salt) concentration (2500, 3000, 3500, 4000mgL−1) and initial pH (3, 5, 7, 9); color and COD was used as indicators of process efficiency. Reactor achieved a complete decolourization and COD reduction of 60.8% at potential of 5V, HRT of 120min, salt concentration of 4000mgL−1 and pH 5. Three intermediate products were detected after electrodegradation with particular m/z values of 388, 300, and 256. The specific design and configuration of reactor employed in this research resulted in voltage and energy losses of 15.35% and 15.25%, respectively.

In Situ Growth of Flexible Polyphenylene-Conjugated Microporous Polymer Films for Fluorescence Detection of the Total Quantity of Developing Agents and Their Oxidation Products

Conjugated microporous polymers (CMPs) are a kind of porous skeleton polymers, which are characterized by extended conjugated skeletons, large specific surface area and structure stability. In this work, a facile and versatile method was developed to fabricate flexible conjugated microporous polymer films for fast detecting the total quantity of developing agents and their oxidation products. Conjugated microporous polymer films were synthesized through in situ one-step approach by Suzuki coupling reaction. With such merits such as intense luminescence, easy synthesis and disposability, the polymer films were employed to detect developers based on fluorescence quenching in the printing wastewater. A linear response to p-benzoquinone, oxidation product of developers, was obtained in the range of 0.05–0.5 μmol·L−1, with a detection limit of 0.015 μmol·L−1. The strategy for in situ growth of flexible polyphenylene-conjugated microporous polymer (PP-CMP) films seems to be a very portable and general method for meeting different analytic purposes.

Complete Autotrophic Process for Nitrogen Removal from Ink- jet Printing Wastewater

Complete Autotrophic Process for Nitrogen Removal from Ink- jet Printing Wastewater

Statistical methods as indicator of offset printing wastewater quality

This study presents the application of different chemometric approaches on the dataset obtained during the monitoring of offset printing wastewater quality in Pozarevac, Serbia. Collecting of wastewaters was performed during a working week, five working days, in five offset printing facilities. Twenty five physico-chemical parameters were analyzed in wastewaters using the standard analytical and instrumental methods. The obtained dataset were subjected to cluster analysis and principal component analysis. Cluster analysis showed four groups of similarity between the printing facilities reflecting the different physico-chemical characteristics and pollution levels of studied wastewaters. Principal component analysis identified two principal components responsible for the data structure explaining 86 % of total variance of offset printing wastewaters. The obtained principal components indicate the parameters that are the most responsible for variation of offset printing wastewaters. This study clearly demonstrates the usefulness of chemometric methods in analysis of printing wastewater quality, identification of the main sources and understanding of spatial variations in wastewater quality. Also, it could be useful for the selection of an appropriate wastewater treatment plant.

Treatment of Dyes Wastewater with TiO<sub>2</sub> Photocatalytic Membrane Reactors

TiO2 photocatalytic membrane reactors (PMRs) are prospective technology of treating dyeing and printing wastewater. The type and structure of the PMRs currently used for dyes wastewater treating were introduced. In these systems TiO2 was successfully separated from water by means of excellent separation performance of membrane, reducing TiO2 loss, enhancing the utilization ratio of catalysts and improving effluent water quality. At the same time dyes and other macromolecular substances were degraded photocatalyticly, greatly improving the stain resistance to membrane and extending membranes service life.

Primary–secondary amino silica nanoparticle: synthesis and dye removal from binary system

In this paper, primary–secondary amino silica nanoparticle (PSASN) was synthesized, and its dye removal ability from single and binary systems containing printing dyes was investigated. The synthesized PSASN was characterized by means of Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and BET analyses. Acid blue 92 (AB92), Direct Black 22 (DB22), Direct Red 31 (DR31), and Direct Red 80 (DR80) were used. The kinetics and isotherm of dye adsorption were studied. The effects of PSASN dosage, pH, salt, and initial dye concentration on dye removal were evaluated. Adsorption kinetic was found to conform to pseudo-second-order kinetics. The maximum dye adsorption capacity (Q0) of PSASN for AB92, DB22, DR31, and DR80 were 113.636, 37.453, 114.943, and 41.152 mg/g, respectively. It was found that dye adsorption on PSASN followed Langmuir isotherm. The results showed that the PSASN as an adsorbent with dye adsorption capacity might be a suitable alternative to remove dyes from colored printing wastewater.

Treatment of real printing wastewater with an electrocatalytic process

Many chemicals used in modern printing processes are either toxic or difficult to decompose, which results in the production of complicated and refractory printing wastewater. In this study, an electrocatalytic technology with different catalytic electrodes was employed to treat a real printing wastewater, and the production rates of hydroxyl radicals were determined. The results indicate that under a voltage gradient of 11Vcm−1, the production concentration of hydroxyl radicals by various electrodes followed a decreasing order of TiO2>DSA (dimensional sustainable anode with IrO2)>graphite, with the values of 8.21×10−3, 5.24×10−3, and 0.86×10−3M, respectively. A lower wastewater conductivity could lead to a greater electric voltage thus contributing to a higher removal efficiency of TOC and chroma. At a current density of 50mAcm−2 and using one pair of electrodes (IrO2+stainless steel), the TOC and chroma removal efficiencies reached 71% and 53% after 60min treatment. Under the same operation conditions but using two pairs of electrodes, the removal efficiencies of TOC and chroma were increased to 75% and 82%, respectively. The removal efficiencies of TOC and chroma could be further raised to 90% and 92% if the electrocatalytic effluent was polished by powder activated carbon absorption.

Optimization of Operating Conditions on Ceramic Printing Wastewater Treatment with Coagulation and Sedimentation Method

The ceramic printing wastewater was treated with coagulation sedimentation method by adopted AlCl3 polymerization (PAC) as a coagulant. In order to optimize the wastewater treatment of operating conditions, with absorbance, turbidity and conductivity for testing index, the PAC dosing quantity, stirring time, stirring intensity and influx water pH value on the influence of the wastewater treatment. The results show that the wastewater absorbance and turbidity with PAC dosing quantity increase, mixing time extension and stirring intensity increase present reduced trend, with the water pH increases present first decreases trend of increase; Proper operating conditions of wastewater treatment: PAC dosing quantity 90 mg/L, mixing time 15 min, mixing strength medium speed and influx water pH value is about seven. On this condition, ceramic printing wastewater treatment of effluent decolorization rate reached 86.9%, turbidity removal rate reached 92.5%, conductivity is 2.05 x 103 s/cm.

Research on Metal Ion Removal of Ceramic Printing Wastewater

The removal of the metal ions in the ceramic printing wastewater was influenced by using, stirring and precipitating of the solution pH, coagulant PAC, coagulant aid PAM and heavy metal scavenger. This experiment investigated the removal effect of the metal ions in the wastewater under different conditions. Flame atomic absorption spectrometry was adopted for the determination of the concentration of metal ions in the wastewater. The studies have shown that alkalization, PAC coagulation treatment have a role in the removal of metal ions in the ceramic printing wastewater. And the chromium and iron removal rate can reached 74.0% and 61.6% respectively. Heavy metal scavenger also have a better role in the removal of metal ions. And the chromium and iron removal rates were 82.3% and 76.2% respectively without dosing PAC. The number of reaction cell has no significant effect on the removal of metal ions.