Color Removal Process Research Articles

Effects of finishing processes on physical properties of knitted fabrics produced by recycled cotton fibers

This study examines conventional wet-finishing processes applicable to fabrics containing recycled cotton fibers. The knitted fabrics were produced using open-end and compact yarns, with up to 80% of the cotton fibers being obtained from mechanical recycling of pre-consumer textile wastes. The study evaluated the effects of these finishing processes on the physical properties of the fabrics based on the recycled fiber ratio, yarn type, and yarn count. After determining the parameters for enzymatic bio-polishing, scouring, and color removal processes, two sequential finishing routes were designed: using the fabrics as mélange without a dyeing process (F1) or coloring them with color stripping and subsequent dyeing (F2). The resulting fabrics were tested for bursting strength, pilling resistance, weight, thickness, air permeability, and abrasion resistance, and the results were evaluated statistically. The study demonstrated that compact yarns provide superior strength, particularly when the F2 process was employed. The F2 process resulted in high pilling resistance and increased breathability of recycled knitted fabrics. The study concluded that the quality of fabrics containing recycled cotton fibers could be optimized by the selection of the appropriate finishing processes.

Removal of Cochineal Dye Color through Atmospheric Pressure Plasma Discharge Jet

The extensive utilization of dyes across diverse industries has resulted in environmental pollution, leading to the degradation of water bodies. To prevent environmental contamination, the use of eco-friendly dyes and innovative processes for dye degradation is crucial. This study aimed to investigate the color removal process of cochineal dye (Dactylopius coccus Costa) using the atmospheric pressure plasma jet (APPJ: Atmospheric Pressure Plasma Jet) technique. The dye extracted from the cochineal insect was treated with APPJ and the resulting color removal process was analyzed. Optical emission spectroscopy (OES) was used to investigate the plasma emission lines, and UV-Vis spectroscopy was used to monitor the color removal process. The results revealed that the decolorization of cochineal dye was a result of an oxidative degradation process caused by the interaction of the reactive species (NO3− and NO2−) generated by the APPJ plasma discharge with the dye molecules. This color removal process occurs in an acidic medium, leading to a pH change from 5.4 to 2.7. These pH changes can be attributed to fluctuations in the concentrations of reactive species such as nitrates and nitrites in the liquid phase. UV-Vis spectroscopy measurements showed that 90% of the cochineal color was removed within the first 10 min of treatment. This study enhances our understanding of natural color removal and provides insights into its mechanism, opening up possibilities for controlled modification and applications in various fields.

Brewing sustainability and strength: Biocomposite development through tea waste incorporation in polylactic acid

This study aims to enhance the mechanical properties of polylactic acid by incorporating black tea waste as an economical and sustainable additive capable of being recycled. The black tea waste, after the hot water color removal process, is milled to a fine and uniform powder size. The combination of these particles with polylactic acid is carried out using a twin-screw extruder. Specimens of pure polylactic acid and biocomposites containing 3 and 5 wt% black tea waste are manufactured using a hot press machine at a temperature of 200 °C. The filaments are also successfully extruded for three-dimensional printing purposes. Scanning electron microscopy images reveal that in the polylactic acid–3% tea biocomposite, the tea particles are appropriately dispersed within the polylactic acid matrix. The tensile test results indicate that biocomposite polylactic acid-3% tea has the highest mechanical properties, with a tensile strength of 67 MPa, demonstrating a 34% increase compared to polylactic acid. Furthermore, the biocomposite of polylactic acid–3% tea waste exhibits the best performance with a fracture energy of 2.5 kJ/m2 in the impact test. Hence, polylactic acid–3% tea biocomposite can be recommended as a suitable sustainable substitute. Finally, numerical simulations are performed on biocomposites containing double keyhole notches. This analysis is conducted to observe the behavior of biocomposite models with double keyhole notch under mixed-mode loading. The critical fracture load of the models is calculated using the strain energy density criterion. It is observed that an increase in the notch inclination angle and notch radius leads to a decrease in the fracture load in the models.

Integrated Fuzzy AHP-TOPSIS for selecting the best color removal process using carbon-based adsorbent materials: multi-criteria decision making vs. systematic review approaches and modeling of textile wastewater treatment in real conditions

ABSTRACT Here, Fuzzy AHP-TOPSIS methodology proposed for selecting the best colour treatment process using carbon-based adsorbent materials. Cost, safety, accessibility, reuse and adsorption capacity were identified as the main criteria for decision making. The priority of the criteria based on the experts’ opinions ordered as accessibility, reuse, adsorption capacity, environment safety, human safety, material cost, equipment cost with BNP = 0.250, 0.217, 0.172, 0.144, 0.105, 0.070 and 0.049, respectively. The consistency ratio was found 0.7% (less than 10%), which was acceptable to prioritise the criteria results. Fuzzy TOPSIS decision matrix with respect to criteria for evaluating the performance of eight carbon-based adsorbent materials in colour removal was formed and adsorbents ranked according to the NCCi as powder activated carbon>granular activated carbon >carbon nano tube >graphene oxide > graphene >reduced graphene oxide >graphite>coal. Finally, the effect of key factors in the treatment of real textile wastewater using PAC was investigated and optimised with RSM-CCF modelling. The optimal value of the parameters for the best productivity (81.60%) were as follows: pH: 3, PAC dose: 9.99 g L−1 and contact time: 83.19 min, respectively. The adsorption equilibrium and kinetic data were fitted with the Langmuir monolayer isotherm model (qmax: 127.431 ADMI/g, R2: 0.999) and Pseudo-first-order kinetics (R2: 0.998). Thermodynamic parameters, i.e. R2 > 0.995, ΔH°> 0, ΔS°> 0 and ΔG°< 0 also indicated colour adsorption are feasible, spontaneous and endothermic in nature.

Removal of Congo Red and Rhodamine B dyes from aqueous solution using unmodified and NH3/HCl-modified wood charcoal: a kinetic and thermodynamic study

In recent years, color removal processes from industrial wastewater which contains dyestuffs have gained great importance. Especially, textile industry wastewater with high volume and variable composition comes first among these wastewaters. These waters bring along many ecological and esthetic problems. In this study, unmodified and acid/base-modified wood charcoal derived from oak wood has been utilized as an eco-friendly adsorbent for removal of anionic dye Congo Red (CR) and cationic dye Rhodamine B (RhB) from aqueous solution. The characterization of raw charcoal was performed using FT-IR, BET and SEM/EDS analysis. The optimum conditions were determined by investigating the effect of adsorption parameters (initial dye concentration, temperature, adsorbent amount, pH and contact time) for efficient removal of dye molecules from aqueous solution by batch adsorption experiments carried out under different conditions and the experimental results were investigated in terms of Langmuir and Freundlich isotherm models. Together with the calculated thermodynamic parameters, the experimental data were applied to pseudo first order, pseudo second order, intra-particle diffusion, Boyd kinetic models and the adsorption mechanism was tried to be explained. The highest removal efficienciency of CR and RhB was achieved as 98% and 92%, respectively. As a result of this study, in which the effectiveness of modified and unmodified adsorbents was compared, it was determined that CR dye was removed at higher efficiency with HCl-modified charcoal. On the other hand, the RhB dye was better removed with NH3-modified charcoal.

Pulsed electrochemical oxidation of acid Red G and crystal violet by PbO2 anode

Present work investigates the application of pulsed electrochemical oxidation technique using DSA anode, titanium coated with PbO2layer, for degradation of Acid Red G (anionic dye) and Crystal Violet (cationic dye). Decolorization efficiency, COD and TOC removal efficiency were measured and contrasted by varying process parameters such as current density, initial organic concentration, pulse frequency, pulse duty cycle and NaCl dosage. Furthermore, decay kinetics for color and COD removal process, average current efficiency and energy consumption were evaluated under diverse arguments. The results indicated that current density, pulse duty cycle and NaCl dosage exerted a positive influence on the performance of pulse electrochemical degradation for ARG and CV, namely, with the growth of relevant influencing factors, the corresponding removal efficiency, kinetic constant of decolorization and COD removal reaction, and specific energy consumption increased accordingly, whereas the average current efficiency gradually decreased. However, the initial concentration of ARG and CV had a negative influence on the pulse electrochemical degradation process, that is, with the increase of initial dye concentration could lead to the reduction of the corresponding removal efficiency, kinetic constant of decolorization and COD removal reaction and energy consumption, on the contrary, the average current efficiency went up. Being different from ARG degradation process, there were some substances adhering to the cathode during CV electrochemical degradation process due to its positive charge. Under same conditions, the degradation indexes of pulse constant current power supply mode were better than those of direct constant current mode, which was coincident for both ARG and CV.

Treatment of Real Textile Wastewater Using Electron Beam Irradiation

Abstract Textile wastewater is known to have a large number of hazardous pollutants, intense color and high chemical oxygen demand (COD) concentration. The electron beam method is considered useful in treatment textile wastewater through chemical oxidation process. In this study, three real textile wastewaters (Sample 1: Reactive Black 5, Reactive Red 10, and Reactive Orange 13; Sample 2: Reactive Red 10 and Yellow GR; Sample 3: Reactive Black 5 and Turquoise Blue HF–G) from textile dyeing company in Ho Chi Minh city were treated by electron beam method. The effect of absorbed doses and hydrogen peroxide (H2O2) at different concentrations on the change of pH, removal capacity, COD and five day’s biological oxygen demand (BOD5) were investigated. The results indicated that color, COD, BOD5 and pH decreased with increasing absorbed dose. A sufficient amount of H2O2 in the radiation process could accelerate the color removal process. In the same condition, a color removal efficiency of ~90% was obtained with EB/H2O2, in contrast with color loss by using EB alone (~71%). These results highlighted the potential of EB radiation technology for treatment of textile dyeing wastewater.

Synthesis of new imine-linked covalent organic framework as high efficient absorbent and monitoring the removal of direct fast scarlet 4BS textile dye based on mobile phone colorimetric platform

Synthesis of a high adsorption capacity material for pollutions removal is temping research and practical field due to increasing the environmental pollution in industrial communities. In this study, a new covalent organic framework based on triazine rings was synthesized and characterized by FT-IR spectra, X-ray diff ;raction pattern, elemental analysis, and nitrogen adsorption/desorption isotherm. Because of the nitrogen riched surface, mesoporous structure, and large surface area, the synthesized N-riched triazine-based COF had a super adsorption capacity. The adsorption properties were examined with the removal of DFS-4BS from textile wastewater. The effective parameter on adsorption performance and color removal processes such as pH, contact time, temperature, and adsorbent dosage were optimized with Central Composition Design. The optimum condition was pH 2; Temperature: 35 °C; Absorbent dosage: 0.01 g; and contact time: 360 min. The obtained maximum adsorption capacity was 8501 mg g−1 (850 wt %) that indicates the super adsorption ability of synthesized N-riched TCOF. To reduce the colorimetric test price and develop the presented adsorbent for field applicability, a mobile phone colorimeter was constructed with accessible equipment and investigate the accuracy of that by comparing the data of mobile phones with the obtained result from UV–vis spectrometer.

Decolorization of dark green Rit dye using positively charged nanobubbles technologies

This study aimed to prove color reduction of dark green Rit dye using nanobubbles (NBs) in comparison with using Al3+ alone and H2O2 alone, and to observe the role of positive NBs, reactive species on decolorization ratio in the processes using NBs alone, ultrasonic NBs, and NBs/H2O2. The color removal processes with Al3+ alone and H2O2 alone were performed using a jar tester while bubbling solutions were injected at a bubble rate of 30% through the bottom of a column reactor containing Rit dye at concentrations of ~500 and ~1200 CU. Our experimental results indicated greater color removal for weaker colors. Further, the decolorization rate using NBs systems was more efficient than that using conventional processes. In both dye concentrations, positive ultrasonic NBs (ZPs of +15 mV to +20 mV) and positive NBs/H2O2 (1 mM) systems were found to be effective treatment processes. The color removal mechanisms were owing to the electrostatic attraction between the positive NBs and dye components; furthermore, reactive species such as OH, HO2, and O2 were fundamental in enhancing Rit dye degradation in ultrasonic NB and NBs/H2O2 systems. More than 90% of Rit dye removal was obtained within 30 min and after 60 min in the ultrasonic NB and NBs/H2O2 systems, respectively. Different decolorization times under various NBs presences were attributed to the transfer from the bubbly regime to aggregate regime, and the reaction kinetics of the reactive species and Rit dye components. The NBs processes were confirmed to be reliable evidence for the decolorization of polluted waters.

Investigation of removal of anthocyanin in turnip juice wastewater by using different adsorbents

The aim of this study is to eliminate the colour pigment of anthocyanin in the composition of turnip juice under different experimental conditions using low cost adsorbents (eggshells, pumpkin seed hulls, almond shells, black–green–red tea wastes, natural clay material). For this purpose, a series of discrete adsorption experiments were performed. Contact time for each set of experiments, adsorbent amount, mixing speed and temperature were fixed at 30 min, 2 g, 150 rpm and 20 °C. The effects of pH change of wastewater (acidic-neutral-basic) on colour removal and adsorption process were examined. The most important advantage of using such adsorbents is their ability to solve colour pollution problem as effective and economical adsorption. As a result of the studies, the colour parameter of the anthocyanins was removed from the wastewater at a low rate (14.08%).

Decolorization and degradation analysis of Disperse Red 3B by a consortium of the fungus Aspergillus sp. XJ-2 and the microalgae Chlorella sorokiniana XJK.

Disperse Red 3B, an anthraquinone dye, was decolorized by a consortium, which was constituted of the fungus (Aspergillus sp. XJ-2) and the microalgae (Chlorella sorokiniana XJK). The consortium performed better than the single system in terms of decolorization and nutrient removal simultaneously in the simulated wastewater of Dispersed Red 3B. The decolorization rate could reach 98.09% by the consortium under the optimized conditions. The removal rate of COD (Chemical Oxygen Demand), TP (Total Phosphorus), and ammonia nitrogen reached 93.9%, 83.9% and 87.6%. Also, the consortium could tolerate higher salt and dye concentration than the single system did. In this co-cultural system, the lignin peroxidase and manganese peroxidase enzyme activities contributed to the degradation of Disperse Red 3B, which reached 86.7 U L−1 and 122.5 U L−1. The result of fermentation liquid analysis with UV-vis, FTIR and GC-MS showed that the colored functional group of the dye was broken and the Dispersed Red 3B was degraded into small molecular compounds with low toxicity. It was suggested that degradation plays a major role during the color removal process. The consortium exhibited greater potential in terms of color removal and water pollutant removal than the separate system did.

INVESTIGATION OF ELECTROCHEMICAL COLOR REMOVAL FROM ORGANIZED INDUSTRIAL DISTRICT (OID) WASTEWATER TREATMENT PLANTS USING NEW GENERATION Sn/Sb/Ni-Ti ANODES

&lt;p&gt;In this study, the application of Sn/Sb/Ni-Ti electrodes for the treatment of waste streams were investigated which is promising for ozone production by electrolysis of water because of their stability and high potential for ozone evolution reaction. These series of anodes have a high electrochemical ozone generation potential at ambient conditions (approximately up to 40% current efficiency). But using and testing of these novel anodes for real wastewater are too limited in the literature. Titanium mesh substrate coated with Sn/Sb/Ni-Ti alloy was used as anode immersed in wastewater at room temperature with platinized titanium cathode. These electrodes used for COD and color removal from OID wastewater in Inegol, Bursa, Turkey. Five operational parameters were evaluated for electrochemical COD and color removal processes, such as pH, salt content, applied voltage/current, current efficiency and contact time. Experimental results showed that after 30 min the electrochemical oxidation efficiency of COD and color could reach up to 98% and 99% respectively at pH 8.2 and temperature of 25°C as the optimum conditions. Current density observed as the most effective parameter for COD and color removal efficiencies. The lowest energy consumption was between 10-25 mA cm-2 of current density with only 0.6 kWh gCOD−1, while the highest energy consumption was 100 mA cm-2 of current density with 9.12 kWh gCOD−1 . The optimum current density value has been found as 50 mA cm-2 with 4.05 kWh gCOD−1 . These results were also supported with ANOVA test.&lt;/p&gt;

Modelling dye removal by adsorption onto water treatment residuals using combined response surface methodology-artificial neural network approach

In this study, response surface methodology (RSM)–artificial neural network (ANN) approach was used to optimise/model disperse dye removal by adsorption using water treatment residuals (WTR). RSM was first applied to evaluate the process using three controllable operating parameters, namely WTR dose, initial pH (pHinitial) and dye concentration, and optimal conditions for colour removal were determined. In the second step, the experimental results of the design data of RSM were used to train the neural network along with a non-controllable parameter, the final pH (pHfinal). The trained neural networks were used for predicting the colour removal. A colour removal of 52.6 ± 2.0% obtained experimentally at optimised conditions (pHinitial 3.0, adsorbent dose 30 g/L and dye concentration 75 mg/L) was comparable to 52.0% and 52.2% predicted by RSM and RSM-ANN, respectively. This study thus shows that optimising/predicting the colour removal process using the RSM–ANN approach is possible, and it also indicates that adsorption onto WTR could be used as a primary treatment for removal of colour from dye wastewater.

Impact of Microaeration and the Redox Mediator Anthraquinone‐2,6‐Disulfonate on Azo Dye Reduction and By‐Products Degradation

This work assessed the impact of microaeration and the redox mediator anthraquinone‐2,6‐disulfonate (AQDS) on both azo dye reduction and by‐products degradation (aromatic amines) in a mesophilic reactor. The experiment was carried out in an up‐flow anaerobic sludge blanket (UASB) reactor with 3.2 L of working volume and hydraulic retention time (HRT) of 24 h. The synthetic effluent contained 50 mg L−1 of the dye Reactive Red 2 (RR2). The reactor was initially operated under anaerobic conditions and, subsequently, was microaerated with atmospheric air (1 mL min−1) and then supplemented with the redox mediator (AQDS) at a concentration of 25 μM. The microaeration effect on dye reduction and by‐products formed was not evident. However, AQDS considerably enhanced RR2 reduction, and its regeneration is not affected by the presence of oxygen. It seems that the cleavage of the double bond between nitrogen groups is a much easier way to start the attack of the azo dye, and it is independent of the presence of oxygen. Thus, the introduction of hydroxyl groups into the aromatic ring was not playing a role in the color removal process. In terms of ecological parameters, the ecological niches were maintained, and the distribution of species increased, despite the majority being generalists, i.e., not specialized in dye degradation. Furthermore, anaerobic species are dominant over facultative species, which explains why there was no population diversity recovery after the microaeration started.

Optimization of batch process parameters for Congo red color removal by Neurospora crassa live fungal biomass with wheat bran dual adsorbent using response surface methodology

The present work deals with the application of response surface methodology (RSM) to study the effects of various operational parameters on the decolorization of Congo red (CR) from dye wastewater. The live fungal biomass of Neurospora crassa along with wheat bran was used as a dual adsorbent for the removal of CR color from aqueous solution. Decolorization experiments were conducted in batch mode by varying experimental factors such as initial pH, initial dye concentration, wheat bran dosage, live biomass dosage, wheat bran particle size, and agitation speed. The process parameters were optimized using central composite design (CCD) to attain the maximum percentage decolorization. Predicted values of percentage color removal were found to be in good agreement with experimental values, which indicates that the suitability of the model and the success of CCD in optimization of CR color removal process. Graphical response surface and contour plots were used to locate the optimum points. The regression model equation for percentage CR color removal was established. The optimum pH, dye concentration, wheat bran dosage, live biomass dosage, wheat bran particle size and agitation speed were found to be 6, 200 mg L–1, 12.5 g L–1, 2% (w/v), 150 μm, 150 rpm, respectively for CR color removal. Further, the batch experiments were conducted to study the effect of electrolytes, surfactants, mixture of dyes, and temperature on dye decolorization. We concluded that the live fungal biomass of Neurospora crassa with wheat bran was shown to be suitable dual adsorbent for adsorption of CR and it can be used effectively in wastewater treatment.

Hydraulic retention time influence on azo dye and sulfate removal during the sequential anaerobic–aerobic treatment of real textile wastewater

In the present study, we evaluate the behavior of real textile wastewater treatment using a system composed of two sequential pilot-scale reactors (anaerobic followed by aerobic) during 622 days. The work focused on the competition between color and sulfate removal processes, when the hydraulic retention time (HRT) was increased in the anaerobic/aerobic reactors from 16/12 hours in phase I (PI) to 4/3 days in phase II (PII). The organic matter was successfully removed in both phases through the system, and the highest efficiency (75%) was achieved in PII. The increase in the HRT did not improve azo dye degradation under anaerobic conditions. Instead, it favored sulfate reduction, which removal efficiency increased from 26% in PI to 75% in PII. Aromatic amines were detected in the anaerobic reactor effluent and removed in the aerobic reactor.

Decolourization of aerobically treated palm oil mill effluent (AT-POME) using polyvinylidene fluoride (PVDF) ultrafiltration membrane incorporated with coupled zinc-iron oxide nanoparticles

Palm oil mill effluent (POME), which is rich in organic matter, is one of the major contributors of water pollution. To date, biological treatment has been employed before it is released into water bodies to minimize the environmental hazards. However, the dark brownish colour of the effluent is still a big challenge to be addressed. In regard to this concern, membrane separation can serve as an attractive solution for this issue. This paper aims to investigate the performance of ultrafiltration nanocomposite membrane embedded with coupled zinc-iron oxide (ZIO) for the decolourization of POME. The ZIO was synthesized through the solution combustion technique by employing zinc nitrate hexahydrate and iron (III) nitrate nonahydrate as the precursors and urea as the fuel. The nanocomposite flat sheet membrane was prepared via phase inversion process. The physico-chemical properties of the MMMs were analysed using zeta potential analysis, SEM, BET and contact angle. Continuous filtration test was carried out to evaluate the capability of the MMMs for colour and COD removal. The results showed that the increase in the ZIO loading has drastically increased the membrane surface negativity and led to the colour removal of 70%. In addition, with the addition of M0.5, the permeation and colour removal had increased 25% and 17% respectively, compared to the pristine PVDF membrane. However, the long term filtration test revealed that the structure of M0.5 collapsed after 4 cycles of washing, but M2.0 still retained its performance. In a nutshell, this study demonstrated that negative surface charge has improved the antifouling properties meanwhile hydrophilicity has contributed to increased water flux during the colour removal process.

Mucilaginous seed of Ocimum basilicum as a natural coagulant for textile wastewater treatment

In this study, Ocimum basilicum L. (basil) has been evaluated as an active natural coagulant for the removal of dye from a model textile wastewater containing congo red. The effect of three parameters including pH, coagulant dose and dye concentration on the color removal and COD reduction were analyzed. A cubic equation could model the color removal process with a R2 of 0.89. The dye concentration was found to be the most significant parameter affecting the color removal. A high color (68.5%) and COD (61.6%) removal efficiency was obtained by using a low amount of the coagulant, 1.6mg/L. The mucilage of O. basilicum was also found to be highly effective in treating real textile wastewater as a sole coagulant and in combination with alum.

Impacto da adição de caulim nas propriedades físico-mecânicas do papel formado por sequências ECF

A indústria de papel é a principal consumidora de caulim. Sua maior utilização no papel é como enchimento, pelo fato de ser mais barato do que a polpa celulósica. O processo de remoção de cor da celulose conhecido como branqueamento é determinante nas características da polpa final. Muito esforço tem sido feito para que processos de branqueamento menos tóxicos sejam viabilizados. No presente trabalho, objetivou-se avaliar a influência de três sequências de branqueamento de polpa kraft de eucalipto na retenção de caulim e nas propriedades do papel formado. A polpa industrial de eucalipto pré-deslignificada com oxigênio foi branqueada pelas sequências D(E+P)DP (referência), A HT D(E+P)DP (A-ECF) e A HT D(E+P)P (ECF-Light). O caulim foi adicionado às polpas celulósicas após seu refino em moinho PFI para 40°SR, correspondendo a uma quantidade mássica de 20% de caulim para cada folha formada. Os resultados apontaram que a adição de 20% de caulim apresentou retenção significativamente menor para a amostra ECF-Light, permanecendo a sequência referência igual à A-ECF; quanto maior o teor de finos, maior foi a retenção da carga; a sequência ECF-Light apresentou maior custo, menor resistência ao rasgo e menor resistência interna das fibras; a lisura e a compressão não foram influenciadas pela escolha da sequência de branqueamento, tanto quanto pela adição de caulim.

In Situ Platinum Recovery and Color Removal from Organosilicon Streams

Resource limitations, increased demand, and the high cost of precious metals (e.g., platinum) have led to the focus on recovery of platinum from organosilicon hydrosilylation streams as a potentially important source of cost savings in the organosilicon industry. In this work, in situ fixed-bed adsorption technology is demonstrated to be an effective platinum recovery and product color removal process. With the in situ Pt recovery process and using a functionalized silica gel scavenging material, a Pt recovery greater than 90% can be obtained both from silane distillation heavy wastes (with initial Pt concentration of around 50 ppm) and from organosilicon products (with initial Pt concentration of around 5 ppm), with suitable temperature and residence time. Long-term bed volume (BV) experiments were also carried out, and very high BV operations of the corresponding streams could be achieved, still with reasonably high Pt recovery at the end of the long-term run, and a Pt loading of about 2% could be obtai...