Dye Sludge Research Articles

A Short Review on Dye-Wastewater Valorization Using Up-Flow Anaerobic Sludge Blanket Reactors

Dye-containing effluent generated in textile industries is polluting and complex wastewater. It should be managed adequately before its final destination. The up-flow anaerobic blanket (UASB) reactor application is an ecofriendly and cost-competitive treatment. The present study briefly reviews the UASB application for dye-containing wastewater valorization. Bioenergy and clean-water production potential during dye-containing wastewater treatment are emphasized to promote resource recovery in textile industries. Hydraulic retention time (HRT), organic loading rate (OLR), pH, temperature, and hydraulic mixing influence sludge granulation, microbial activity, and dye removal. HRT and OLR ranges of 6–24 h and 1–12 kg m−3 d−1 of chemical oxygen demand (COD) at a mesophilic temperature (30–40 °C) are recommended for efficient treatment. In these conditions, efficiencies of color and COD of 50–97% and 60–90% are reported in bench-scale UASB studies. Complex dye structures can hinder biomineralization. Pretreatment may be necessary to reduce dye concentration. Carbon-source and redox mediators are added to the UASB reactor to expedite kinetic reactions. A biogas yield of 1.48–2.70 L d−1 in UASB, which treats dye-containing effluents, is documented. Cotreatment of dye wastewater and locally available substrate could increase biogas productivity in UASB reactors. Organic waste generated in the textile industry, such as dye sludge, cotton, and starch, is recommended to make cotreatment cost competitive. Bioenergy production and water reuse allow environmental and economic benefits. Studies on combined systems integrating UASB and membrane processes, such as ultrafiltration and nanofiltration, for the production of reusable water and pretreatment of wastewater and sludge for improvements in biogas production might realize the complete potential for resource recovery of UASB technology. UASB bioenergy usage for integrated treatment trains can reduce operating costs and assist process sustainability in the textile industry.

ZnS modified N, S dual-doped interconnected porous carbon derived from dye sludge waste as high-efficient ORR/OER catalyst for rechargeable zinc-air battery

Facile and rational design of high-efficient oxygen reduction reaction (ORR)/oxygen evolution reaction (OER) bifunctional electrocatalysts is significant for rechargeable Zinc-air batteries. In this study, ZnS modified N, S dual-doped interconnected porous carbon (ZnS/NSC) derived from the dye sludge waste is successfully fabricated via a facile ZnCl2-assisted pyrolysis process. The effect of ZnCl2 and carbonization temperature on the microstructure and electrocatalytic performance is systematically investigated. By virtue of the synergistic effect between ZnS nanoparticles and N, S dual-doped porous carbon network, the obtained catalyst ZnS/NSC calcined at 1000 °C exhibits a decent bifunctional electrocatalytic performance with potential gap (ΔE=EOER,10-EORR,1/2) of 0.76 V comparable with commercial electrocatalysts (Pt/C and RuO2). In addition, a rechargeable zinc-air battery employed ZnS/NSC-1000 as the air cathode also displays the favorable electrochemical performance, in which the power density is 125 mW cm−2, the specific capacity is 763.27 mAh g−1 and the cycling stability at 10 mA cm−2 is more than 85 h, indicating a promising application prospect in rechargeable Zinc-air batteries.

Comparative assessment for removal of anionic dye from water by different waste-derived biochar vis a vis reusability of generated sludge

In this study, four biochars prepared from different crop residue waste i.e. sugarcane bagasse (SBB), coconut shell (CNB), paddy straw (PDB), and distilled waste of lemongrass (LGB) were evaluated for removal of Remazol Brilliant Blue R from the aqueous system. The RBBR adsorption capacities of biochar were 97–79% for SBB, 99.9–99.47% for CNB, 66.1–48% for PDB, and 78–68% for LGB, dominantly controlled by their aromaticity and mineral content. The Langmuir and Freundlich isotherms and pseudo-second-order kinetic models have described the chemisorption of RBBR on biochar surfaces. The thermodynamic data suggested that adsorption was spontaneous and endothermic. These biochars demonstrated excellent reusability (till four cycles with 50–61% regeneration). The purified water and biochar dye sludge demonstrated no phytotoxicity. The findings obtained in this study may provide supports for the potential of biochars for anionic dye removal from water and utilization of generated sludge for zero waste-producing technologies in the future.

Sustainable biotreatment of textile dye effluent water by using earthworms through vermifiltration

ObjectiveA research was conducted to explore the reuse possibilities of the textile dye effluent propagated from the textile dye industry. The current study reports vermiculture based effluent treatment method through the chief intention of interconversion of contaminated effluent water into ecologically harmless water. MethodsHence a new and typical technology, vermifiltration of effluent using wastewater eating earthworms has been evolved. ResultsOutcome recommended that vermifilter revealed maximal chemical oxygen demand (126 mg L−1), Biological oxygen demand (56 mg L−1), Total suspended solids (181 mg L−1) and Total dissolved solids (298 mg L−1) decreased by 85–89%, 76–80%, 73–77% and 71–76% by the result of vermifiltration. Bioavailability of some heavy metallic compounds such as Ni, Cd, Cu, Zn, Pb, and Cr brought down considerably during vermifiltration. Vermifilter and control metal accumulations ranged from 0.2 ppm to 2.34 ppm and from 0.10 ppm to 2.98 ppm respectively. The SEM illustration reveal that the morphology of the vermicast of control and vermifiltration which is differing significantly. When the concentration of textile dye sludge increases it also increases the destruction of tissues constantly. Histological of the gut domain exposed moderate harm in 50% dilution. ConclusionsTherefore, these studies concluded that vermifiltration can be used as an eco-friendly technique which can be considered the same as a paradigm for textile industries effluents remedial development.

Nitrogen self-doped porous carbon nanosheets derived from azo dye flocs for efficient supercapacitor electrodes

The present work introduces a new method for the recycling of waste flocculation sludge to prepare electrode materials for supercapacitor. Hazardous azo dye was removal from textile dying wastewater by a new chitosan-based flocculant, and the generated dye sludge flocs was used as a nitrogen-containing precursor for the fabrication of N-doped carbon materials. The influence of azo dye on specific surface areas, nitrogen content, pore evolution of the resulting products and their electrochemical performance were investigated in detail. The results demonstrated a dual role of azo dye worked as both a nitrogen resource and pore-forming agent. The resulting N-doped carbon nanosheets derived from azo dye flocs demonstrated high electrochemical capacitance and good stability for supercapacitor electrode, which is attributed to the unique nitrogen doping, higher specific surface area and efficient charge transfer ability.

N, S Dual-Doped Carbon Derived from Dye Sludge by Using Polymeric Flocculant as Soft Template.

Dye sludge is a major by-product and it will bring critical environmental problems in the textile industry. In this study, dicyandiamide formaldehyde resin (DFR) is used as an effective flocculating agent for the removal of anionic dyes from textile dye wastewater. Employing dye-contaminated sewage sludges as precursors, N, S dual-doped carbon materials are successfully synthesized by using DFR as a soft template. The specific surface area, morphology, and pore structure of the resulting annealed products can be easily controlled by changing the DFR content of the dye sludge. The oxygen reduction reaction performance of optimal carbon material (N, S-DF-2) is close to commercial 20% Pt/C in alkaline medium, including onset potential (0.98 V), half-wave potential (0.82 V), as well as limiting current density (5.46 mA·cm−2). Furthermore, it also shows better durability and crossover resistance. In addition, N, S-DF-2 exhibits a large specific capacitance (230 F·g−1 at 1 A·g−1) and super capacitance retention (nearly 98% at 10 A·g−1) after 2500 cycles as supercapacitors electrodes. This work opens up a new method to take full advantage of organic polymeric flocculant as a soft template to prepare N, S dual-doped carbon materials, which will be beneficial for the reuse and recycling of sewage sludge, as well as for the production of good quality energy conversion and storage materials.

Combination of Iron Chloride and Polyacrylamide as Coagulant-Flocculants to Remove Pollutants in Dye Wastewater

Dye Industrial developments have been increasing over the years and have created various environmental problems for water resources. This study was carried out in order to reduce the concentration of colour as well as the COD concentration by coagulation (Iron chloride) and flocculation (Polyacrylamide) using a standard jar test apparatus. The coagulation and flocculation processes were completed using Response Surface Methodology – Central Composite Design in order to see the effect of pH on iron chloride and polyacrylamide at optimum conditions. The analysis of zeta potential was done at various pH levels to compare the reduction of COD and colourant at various levels. Further analysis using the sludge produced included measuring for phytotoxicity using Lactuca sativa seeds. The treatment showed the highest colour removal with 95% (31 pt. co) and 92.0 % (42 mg/ L) COD reduction at pH conditions of around 5.4, 375 mg/ L of coagulant and 28 mg/ L of flocculant. Charge neutralization occurred when the pH moved to acidic region of 4-6. It was found that pH significantly influenced Iron chloride and Polyacrylamide for both responses (colour and COD). The phytotoxicity assessment indicated the mortality rate is increased with an increase in sludge concentration. Results revealed that FeCl3PAM at 100% undiluted dye sludge recorded the highest mortality rate.

Removal of hexavalent chromium from aqueous solution using novel dye-based adsorbent prepared by flocculation

ABSTRACTIn this paper, the dye sludge which was prepared from Congo red solution by flocculation method was further modified by catechol and 1, 6-hexanediamine before usage to remove Cr(VI) ions. This particles were characterized by multiple testing means and the effects of removal, such as contact time, pH value, initial concentration, and temperature, were studied by batch mode. The maximum adsorption capacity of Cr(VI) was 282.48 mg/g and the whole process was spontaneous and endothermic. Hopefully, with the advantages of facile preparation and high adsorption capacity, the dye-based adsorbent has broad application prospects in the field of wastewater treatment.

PH-responsive chitosan-based flocculant for precise dye flocculation control and the recycling of textile dyeing effluents.

In this work, we introduce a simple and effective method for the controlled release of dye from dye saturation flocs by a well-designed pH responsive chitosan-based flocculant. The dye flocculation capacities could be precisely controlled from 0.5 to 2 g g−1 by simply adjusting the pH of the desorption solution. A series of flocs with different dye flocculation capacities was prepared and used as nitrogen-rich precursors to prepare nitrogen-doped carbon materials through one-step carbonization. The results demonstrate that the specific surface areas, pore structures and supercapacitance performance of the resulting N-doped carbon materials could be readily controlled by varying the dye flocculation capacity. By using a dye sludge floc with an appropriate dye flocculation capacity (1.5 g g−1) as a precursor, the resulting N-doped material exhibited a high specific capacity and good cycling performance for a supercapacitor electrode. The unique pH-responsive properties of the chitosan-based flocculant facilitated easy tuning of the surface cationic degree and deprotonation behavior by varying pH. This work presents a new concept for balancing between environmental capacity and energy capacity using a smart pH-responsive carrier system based on modified chitosan, which is highly promising for the recycling of industrial wastewater to produce energy materials.

Thermochemical behaviorsof textile dying sludge, paper mill sludge, and their blends during (co-)combustion

This study aimed at the quantification of thermochemical behaviors of textile dye sludge (TDS), paper mill sludge (PMS), and their various blend ratios during (co-)combustion. Changes in mass loss percentage (MLP) and rate (MLR) were estimated as a function of temperature, heating rate, and blend ratio. Our results pointed to a direct influence of blend ratios on mass loss percentage. Stochastic uncertainties and sensitivities associated with best-fit predictions of MLP and MLR responses were detected using all-at-once versus one-at-a-time Monte Carlo simulations. Co-combustion of TDS and PMS provided more flame stability owing to their volatile matter contents than did the combustion of pure TDS or PMS. The high C and H contents of TDS relative to those of PMS led to high lower heating value (higher energy). Effect of increased temperature on the co-combustion manifested itself in the breakdown of (hemi-)cellulose initially and lignin progressively in TDS and PMS. The increasing TDS of the blend ratio increased both MLP and MLR. Stochastic uncertainty analysis of the deterministic empirical models pinpointed overestimation by 15.6% in mean MLP and by 50% in mean MLR. Sensitivity analysis pointed to blend ratio as the most influential predictor on both MLP and MLR.

Applicability of solidified/stabilized dye sludge char as a landfill cover material

The applicability of solidification/stabilization (S/S) to reduce leaching potential of metal(loid)s from dye sludge char (DSC) and the suitability of the treated DSC as a landfill cover material was investigated. The dye sludge charred at 350ºC (DSC350) and 550ºC (DSC550) was solidified and stabilized by the amendment of cement, lime, ladle slag or hydroxyapatite (HAP). Leaching potential of metal(loid)s from the binder-amended DSC550 was below the Korean Standard Leaching Test (KSLT) and US EPA Toxicity Characterization Leaching Procedure (TCLP) criteria. DSC550 had higher Unconfined Compressive Strength (UCS) than DSC350 due to higher ash content and less volatile matter content. Calcium oxide and silica present in cement, lime or ladle slag enhanced the UCS of DSCs. The dose of 0.05 g cement, 0.075 g lime or 0.075 g ladle slag per g of dry DSC550, respectively was optimum to meet the UCS criteria (350 kPa), but not HAP. After blending with a natural soil, the hydraulic conductivity of the binder-amended DSC550 was higher than that of clayey soil (1 × 10−5 cm/s to 1 × 10−6 cm/s). Further study such as blending with clayey soil is needed to decrease hydraulic conductivity to 10−5 to 10−6 cm/s.

Reusable CoxNi1−x dye adsorbents as supercapacitor electrode materials

A strategy to fabricate an electrode material by sintering a dye sludge consisting of a CoNi adsorbent with Congo Red under a N2 atmosphere.

Treatment of textile milldye sludge by vermicomposting using Perionyx excavatus species

The accumulation of solid waste sludge from Textile dye sludge causes a great problem in its safe disposal. Perionyx excavatus were cultured under laboratory condition with 60-80%moisture in mud pot container following with the mixing ratio of TMS (Textile Mill Sludge) + SD(Sawdust) designated as X (1:1) respectively add inoculums (EM) Effective microorganisms and (CD) Cow dung were also used in the above ratio. Once in 15days upto 90days number of hatchling, worm growth rate and the weight of earthworms were determined and analysed statistically. On the basic of the efficiency of four treatments with control condition, (EM) separately, (CD) separately and (EM+SD) combined together were analysed to support the reproduction and growth of Perionyx excavatus has been done. The growth rate, weight gain, and hatchling production observed in the mixed ratio of TMS+SD (1:1) ratio with the above treatments were determined and better combination of mixed ratio with appropriated inoculums was determined. The mixed of TMS+SD+(EM+CD) gave high growth rate, weight gain and hatchling production of selected vermiculture Perionyx excavatus. Hence TMS in combination SD in (1:1ratio) can be used for vermiculture.

Moringa oleifera-mediated coagulation of textile wastewater and its biodegradation using novel consortium-BBA grown on agricultural waste substratum.

Generation of secondary sludge is a major concern of textile dye removal by coagulation process. Combinatorial coagulation-biodegradation treatment system has been found efficient in degradation of coagulated textile dye sludge. Moringa oleifera seed powder (700mgL-1) was able to coagulate textile dyestuff from real textile wastewater with 98% color removal. Novel consortium-BBA was found to decolorize coagulated dye sludge. Parameters that significantly affect coagulation process were optimized using response surface methodology. The bench-scale stirred tank reactor (50-L capacity) designed with optimized parameters for coagulation process could efficiently remove 98, 89, 78, and 67% of American Dye Manufacturer's Institute (ADMI) in four repetitive cycles, respectively. Solid-state fermentation composting reactor designed to treat coagulated dye sludge showed 96% removal of dye within 10days. Coagulation of dyes from textile wastewater and degradation of coagulated dye sludge were confirmed by Fourier transform infrared spectroscopy (FTIR) analysis. Cell morphology assay, comet assay, and phytotoxicity confirmed the formation of less toxic products after coagulation and degradation mechanism.

Removal of Dye Wastewater COD by Sludge Based Activated Carbon

Chen, J.; Wang, X.; Liu, X.; Huang, J., and Xie, Z., 2015. Removal of dye wastewater COD by sludge based activated carbon.In this paper, activated carbon prepared by chemical activation based on dye sludge was used to treat dye wastewater to remove dye wastewater COD. Experiments with KOH and H3PO4 treated the original activated sludge, and set adding fly ash activated sludge as the control group. COD removal experiment results showed that: KOH as activator, the activation temperature and activation time is 60 min at 600 conditions activated sludge obtained with relative maximum iodine value, and when the adsorption time in 15 min ˜ 20 min time, COD removal rate could reach above 95%. Under the same conditions, raw sludge directly activated sludge pyrolysis also has good COD removal; the best removal rate is up to 90%. The experimental results of COD removal of activated carbon in the fly ash added after the original sludge pyrolysis obtained showed that the addition of fly ash to COD removal did not play a synergistic effect. This work provided a simple and eco-friendly method for dye wastewater treatment with recycling of waste.

Zinc chloride as a coagulant for textile dyes and treatment of generated dye sludge under the solid state fermentation: Hybrid treatment strategy

Dye sludge generation is major drawback of coagulation process. Efficient hybrid technology by combining coagulation and solid state fermentation (SSF) has capacity to solve generated dye sludge problem. Coagulation of 100mg/L Reactive Red 120 (RR120) using ZnCl2 showed 99% color removal. Mixture of textile dyes (MTD) and textile wastewater (TW) showed 96% and 98% ADMI (American Dye Manufacturing Institute) removal after coagulation by ZnCl2. 92% and 94% ADMI removal from MTD and TW dye sludge and 96% decolorization of RR120 sludge was observed respectively by developed microbial consortium (DCM) in 72h under SSF. Scale up of coagulation process by coagulation reactor (CR) having 50L capacity operated for 30min/cycle. CR showed average 94% ADMI removal from TW in 10 successive cycles. Scale up of SSF composting bioreactor (CB) showed complete dye removal from dye sludge obtained from CR (500L of TW) in 30days.

Combination of chemical and enzymatic treatment for efficient decolorization/degradation of textile effluent: High operational stability of the continuous process

Textile effluent is characterized by high colour, chemical oxygen demand and conductivity due to presence of a large number of recalcitrant compounds. The effluent is often discharged without an effective treatment leading to contamination of water bodies. In the present study, a combination of mediator assisted laccase and chemical treatment was used for decolorization of effluent from a local textile mill in a continuous enzyme membrane reactor (EMR). Treatment of the effluent first with laccase and ABTS (2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)) lead to about 60% decolorization but was accompanied by membrane fouling. Addition of alum further coagulated 90% of the residual colour but the process was associated with dye sludge formation and ABTS could not be recovered from the treated effluent. Reversal of the treatment sequence was effective in that 85% decolorization was achieved in the EMR and the process could be operated for over a period of 15 days. No sludge formation was noticed and membrane fouling was negligible. Most importantly, about 60% ABTS could be recovered from the treated effluent. Analysis of the treated effluent by mass spectrometery indicated extensive breakdown of the dye molecules by laccase and ABTS and the breakdown products were neither toxic nor mutagenic as assessed by measurement of the oxygen consumption rate and the standard Ames test.

Selective photodegradation and backfilling for regeneration of the inorganic–organic hybrid composite Fe3O4@C18ADB@Zn2SiO4 which captures organic pollutants from aqueous solution

The Fe3O4@C18ADB@Zn2SiO4 hybrid composite was synthesized, and it efficiently adsorbed organic pollutants. The resultant dye sludge was degraded by UV–H2O2 photocatalysis in the presence of Na2SO4, and the sorbent was regenerated by backfilling with C18ADB.

Treatment of Direct Blending Dye Wastewater and Recycling of Dye Sludge

A new sorbent material, barium sulfate-Direct Blending Yellow D-3RNL hybrid (BSD), was synthesized and characterized by various methods. Both the anionic dyes, Reactive Brilliant Red X-3B and Weak Acid Green GS were hardly adsorbed by the BSD material, while the sorption of Ethyl Violet (EV) and Victoria Blue B were extremely obvious. The sorption of cationic dyes obeyed the Langmuir isotherm model, which depended on the electric charge attraction. The saturation amount of EV adsorbed onto the BSD material approached to 39.36 mg/g. The sorption of EV changed little with pH from 3 to 12 while it increased with increasing levels of electrolyte. A dye wastewater sampled from Jinjiang Chemicals was treated, and the color removal rate was more than the COD removal rate. In addition, the cationic dye-BSD sludge was utilized as a colorant fill-in coating. The light stability and thermal stability of the colorant was measured and exhibited good features. This work provided a simple and eco-friendly method for dye wastewater treatment with recycling of waste.

SN@silicate: an anionic dye sorbent and its reuse

It is difficult for dye-synthesizing wastewater to be treated efficiently together with eco-friendly disposal of dye sludge. Octadecyl dimethyl hydroxyethyl quaternary ammonium (SN) was hybridized with magnesium silicate, and then characterized by various techniques. The SN bilayer stacking via hydrophobic interactions intercalated into the magnesium silicate sheets and caused an interlayer increase to 4.9 nm. More than 40% SN was embedded so that the hybrid contained a large number of positive charges and hydrophobic areas. It exhibited a faster adsorption to anionic dyes with higher capacities from 108 to 553 mg g−1 than for conventional sorbents. In addition, it captured microcystin-LR from water according to the lipid-water partition model. The resultant dye sludge was added into epoxy top coating and paint to fabricate colored films with an electric resistance decrease to 0.75 × 107 Ω. The facile preparation of such a functional material provided a “killing two birds with one stone” approach, from treatment of dye wastewater to disposal of the dye sludge, turning it to an antistatic colorant.