Chrome Tanning Wastewater Research Articles

Chrome-Free Tanning: Effect of a Combination Tannage Based on Mimosa and Biogenic Silica from Rice Husk

Chromium (III) sulfate is a popular tanning agent for producing leather. However, chrome tanning wastewater is one of the problems in the leather tanning industry. To prevent this, tanning using vegetable materials can be used in the leather tanning process. One of the natural ingredients that can be used is mimosa. However, mimosa is relatively expensive, so a substitute/combination tanning agent is needed to make tanning costs cheaper. This research aims to determine the effect of using a combination of mimosa and silicic acid from rice husk (RHSA) tanners on the quality of the tanned leather produced. This research uses a completely randomized factorial design with mimosa and RHSA as factors. The analysis shows that the best treatments were 20% mimosa and 20% RHSA. In addition, the analysis shows that the treatment met the standard. The resulting shrinkage temperature was 84 °C, tear strength was 39.98 N mm-1, tensile strength was 26.42 N mm-2 and elongation at break was 41%. Combination tanning also shows no significant difference from conventional tanning and reduces mimosa without decreasing leather quality.

Chrome-Free Tanning: Effect of a Combination Tannage Based on Mimosa and Biogenic Silica from Rice Husk

Chromium (III) sulfate is a popular tanning agent for producing leather. However, chrome tanning wastewater is one of the problems in the leather tanning industry. To prevent this, tanning using vegetable materials can be used in the leather tanning process. One of the natural ingredients that can be used is mimosa. However, mimosa is relatively expensive, so a substitute/combination tanning agent is needed to make tanning costs cheaper. This research aims to determine the effect of using a combination of mimosa and silicic acid from rice husk (RHSA) tanners on the quality of the tanned leather produced. This research uses a completely randomized factorial design with mimosa and RHSA as factors. The analysis shows that the best treatments were 20% mimosa and 20% RHSA. In addition, the analysis shows that the treatment met the standard. The resulting shrinkage temperature was 84 °C, tear strength was 39.98 N mm-1, tensile strength was 26.42 N mm-2 and elongation at break was 41%. Combination tanning also shows no significant difference from conventional tanning and reduces mimosa without decreasing leather quality.

Treatment of Tannery Effluent Using Combined Electrocoagulation and Adsorbent of Powdered Marble

This paper discusses the ability to remove chromium and COD from a real chrome tanning wastewater by use of Electrocoagulation (EC) coupled with adsorption using Powdered Marble (PM) added to a batch stirred EC cell with a pair of duralumin electrodes. The effects of current density, adsorbent dose and contact time were studied. In comparison to the conventional EC process, the coupling of electrocoagulation and adsorption using powdered marble showed that the addition of an appropriate powdered marble improved the removal of Cr(III) and COD using lower current densities and a short contact time. Nearly 99% of Cr(III) and COD were removed from tanning effluent with an initial chromium concentration of 3.21 g/L and COD of 3.75 g/L. the results obtained showed better performance using combined electrocoagulation and adsorbent of powdered marble compared to the simple EC.

Application of co-immobilized microbial biochar beads in hybrid biofilter towards effective treatment of chrome tanning wastewater

This paper aims to scrutinize the comparative performance of hybrid biofilter via column mode to boost the reduction rate of Cr (VI) and organic pollutants in various pre-treated tannery wastewater. The pre-treated water through aluminium formate, aluminium sulphate, and ferric chloride were passed through two divergent biofilter medium discretely with (i) immobilized sodium alginate microbial beads (Im/S.AM.B) and (ii) co-immobilized microbial biochar beads (Co-im/B.M.B). Biosorption efficiency of the hybrid biofilter was examined with respect to pH, initial adsorbate concentration, time, flow rate, breakthrough curve, and regeneration studies. The results exhibited that aluminium formate coagulant pre-treated wastewater when passed through Im/S.AM.B under optimized conditions, the reduction rate of Cr (VI), COD and sulphate was 92.5%, 89.5% and 75%, respectively, whereas Co-im/B.M.B surpassed it by 6.7%, 6.5% and 19% respectively, with a contact time of 90 min, flow rate 2 mL/min, depth 30 cm and pH 6. Further, the raw and treated sample of Co-im/B.M.B was studied for its morphology and surface chemistry via FE-SEM, EDX, FTIR and XRD analysis. The results revealed that Cr (VI) reduction is predominantly through precipitation, electrostatic attraction, and metal complexation. It was observed that electrostatic attraction of cationic charged biochar surface to Cr (VI) ions results in the reduction of Cr (VI) to Cr (III) and complexation between Cr (III). Further, the functional groups present on the microbial biomass (DPAML065) surface were also found responsible for Cr (VI) reduction. Thus, Co-im/B.M.B in hybrid biofilter presents an economical approach in reducing Cr (VI) from tannery wastewater.

Chromium adsorption on coir pith charcoal from tannery wastewater

Emission of high chrome tanning wastewater is catastrophic for the environment. In this work, the effectiveness of coir pith charcoal is stated for the removal of chromium from tannery wastewater. The charcoal yield from the coir pith was 2.4%. The prepared charcoal was characterized by Fourier transform infrared spectroscopy (FT-IR). The efficiency of coir pith charcoal for chromium removal was assessed experimenting with various parameters e.g., charcoal dose, contact time, and relative pH. The content of chromium in the raw wastewater and after treatment at filtrate was 3439.2 mg/L and 14.9 mg/L, individually. In the batch experiment at optimized condition, for 75 mL chrome wastewater at 4 g charcoal dose with 15 min contact time, the chromium removal efficiency was attained 99.6%. The level of chloride (Cl-), chemical oxygen demand (COD), and biochemical oxygen demand (BOD) were significantly reduced by 65.7%, 93.7%, and 95.6%, respectively. The use of coir pith charcoal could be an alternative source for the removal of chromium from chrome containing wastewater.
 Bangladesh J. Sci. Ind. Res.56(1), 53-60, 2021

Chromium Adsorption on Banana Rachis Adsorbent from Tannery Wastewater

This study investigates the banana rachis adsorbent for adsorption characterization, removal, and recovery of the chromium ion from the chrome tanning wastewater. The batch analysis was conducted to find out an adsorbent dose, contact time, relative pH of the aqueous solution, and initial and final chromium value in the filtrate. The equipped adsorbent was studied by the Fourier transform infrared spectroscopy (FT-IR) analysis to reveal the associated functional groups during adsorption. Batch adsorption examination reveals the optimum conditions of 3 g adsorbent input for 75 mL wastewater at 15 min contact time. The adsorption mechanism showed chromium removal 99.64% with the obtained reduction of biochemical oxygen demand (BOD), chemical oxygen demand (COD), and chloride (Cl-) 96.65%, 93.18%, and 59.62%, respectively. The adopted method followed the pseudo-second-order kinetics and Freundlich isotherm for physical adsorption. Primary desorption studies exhibit a scope for the reuse of chromium from the adsorbed adsorbent. Moreover, in comparison with other studies, the study discloses that banana rachis might be utilized as a feasible adsorbent to be adopted in industrial wastewater treatment, especially chrome tanning wastewater in the tannery.

Treatment of highly concentrated tannery wastewater using electrocoagulation: Influence of the quality of aluminium used for the electrode

This paper deals with the ability of electrocoagulation (EC) to remove simultaneously COD and chromium from a real chrome tanning wastewater in a batch stirred electro-coagulation cell provided with two aluminium-based electrodes (aluminium/copper/magnesium alloy and pure aluminium). Effects of operating time, current density and initial concentration of Cr(III) and COD have been investigated. The concentrations of pollutants have been successfully reduced to environmentally acceptable levels even if the concentrated effluent requires a long time of treatment of around 6h with a 400A/m2 current density. The aluminium alloy was found to be more efficient than pure aluminium for removal of COD and chromium. Dilution of the waste has been tested for treatment: high abatement levels could be obtained with shorter time of treatment and lower current densities. Energy consumption of the electrocoagulation process was also discussed. The dilution by half of the concentrated waste leads to a higher abatement performance of both COD and chromium with the best energy efficiency.

Removal of Cr(III) from chrome tanning wastewater by adsorption using two natural carbonaceous materials: Eggshell and powdered marble

In the present paper, eggshell and powdered marble, two carbonaceous materials, were used to remove Cr(III) ions from a real chrome tanning wastewater. The effects of initial effluent pH, adsorbent dose, contact time and temperature were studied. The maximum uptake of chromium ions was obtained at pH 5.0 with the dose 20 g L−1 and 12 g L−1 for eggshell and powdered marble respectively. Adsorption equilibrium was reached after 14 h contact time for eggshell and only after 30 min for powdered marble. Under these conditions, almost 99% Cr(III) was removed from chrome tanning wastewater having an initial concentration of chromium of 3.21 g L−1. Kinetic data were satisfactorily described by a pseudo-second order chemical sorption model. The equilibrium rate constant was notably greater for powdered marble than for eggshell with 1.142·10−3 (g mg−1 min−1) and 0.041·10−3 (g mg−1 min−1) respectively. The adsorption isotherm were well described by a Langmuir model and showed that the interaction of chromium with the two adsorbents surface is a localized monolayer adsorption with a smaller energy constant for the powdered marble than for eggshell (0.020 (L mg−1) and 0.083 (L mg−1) respectively). The powdered marble was able to adsorb faster a large amount of Cr (III) in comparison to eggshell. The use of a standardized lettuce seed bioassay allowed evaluating a better effectiveness of the Cr adsorption on the powdered marble, removing up to 40% of the treated effluent toxicity than by eggshell 25%.The powdered marble could be considered as an effective, low cost carbonaceous material to be used for chromium removal from tanning wastewater.

Removal of Chromium (III) from Tannery Wastewater by Bioaccumulation Method Using Vallisneria sp. River-weed

The presence of chromium (III) in the wastewater is one of the major concerns for the tannery industry in Bangladesh. In this study the removal of chromium (III) from tannery effluent has been carried out by bioaccumulation method using abundantly available Vallisneria sp. river-weed in river all over Bangladesh. Various factors influencing the uptake of chromium, viz., quantity of river-weed, concentration of chromium (III), pH of the solution and duration of treatment have been optimized. Chemical modifications of the river-weed through pretreatment with H2SO4, CaCl2 and MgCl2 showed improved removal efficiency of chromium (III). Langmuir isotherm has been fitted for 0.5 g of river-weed. The dynamic method of treatment of protonated river-weed with a chromium (III) solution at a pH of 3.2 for duration of 4 days gave the maximum uptake of about 81%. A similar uptake has been established for commercial chrome tanning wastewater. In addition, the potential reuse of chromium-containing river-weed for the preparation of basic chromium sulfate (tanning agent) has been demonstrated.Dhaka Univ. J. Sci. 63(2):91-96, 2015 (July)

Biomass of Termitomyces clypeatus for chromium(III) removal from chrome tanning wastewater

Chrome tanning wastewater generated during leather processing is one of the major source of aquatic contamination which has deleterious effect on the environment. To deal this problem, many types of biosorbents have been used so far. In this study, fugal biomass of Termitomyces clypeatus, a byproduct of enzyme, and fermentation industry have been employed for Cr(III) removal from chrome tanning effluent. The maximum metal uptake (q e) of 24.84 mg g−1 was obtained with an optimum pH and temperature of 4 and 60 °C for an initial metal concentration of 100 ppm at an adsorbent dosage of 2 g L−1. Adsorption process was best fitted by pseudo-second-order kinetic model. Sorption process obeys Freundlich adsorption isotherm model, rather than Langmuir. The presence of functional groups and morphological changes on the biomass responsible for metal uptake was confirmed by FT-IR and scanning electron microscopy–energy dispersive X-ray spectroscopy analyses.

Recovery of Cr(III) from tanning process using membrane separation processes

In chrome tanning wastewater study, a wastewater treatment alternative was decided. This treatment alternative contains cartridge filter, ultrafiltration [UF1 (20 kDa), UF2 (50 kDa), UF3 (150 kDa)], nanofiltration NF (XN45), and reverse osmosis RO (ACM2). Chrome tanning wastewater was given to the other membranes to increase the life time of the membranes after cartridge filter application. The wastewater from cartridge filter was given to 3 different UF membranes which have different pore diameters (20, 50, and 150 kDa) with 3 different pressure (6, 8, and 10 bar) in this alternative. For this treatment alternative, for 200 m3/G flow, 8 pieces of (273 m2) UF (20 kDa), 8 pieces of (160 m2) NF (XN45), and 12 pieces of (375 m2) RO (ACM2) membranes were used. The total investment for this treatment alternative was calculated as 228,415 €, and process cost was calculated as 2.77 €/m3; however, for the classical treatment facility, investment was calculated as 345,400 €, and process cost was calculated as 0.8 €/m3. As a result when compared to classical treatment systems, the membrane technology was found to have more economic the investment and the process costs.

Application of CRBD to Reducing Pollution of Leather Tanning Wastewater

Trivalent chrome has an abroad application in the area of leather tanning, electrolytic plating and dyeing due to the strong capability of coordination. Pollution caused by chrome salts cannot be ignored. This paper proved that the chrome tanning wastewater can be treatment by chrome chelates (CRBD). The supernatant was reused in washing and pickling process and chromium sludge was utilized to make regeneration chrome-tanning agents; which all not only protect the environment but also save production cost. A series of experiment results showed that SO42-and oil contents increased slightly as well as Cl-content decreased when the tanning wastewater recycled several times. The total chrome content was up but the influence evaluated by the finish leather was not evident. Items of wet-blue leather and finish leather were tested such as shrinkage temperature, Cr2O3in the leather, softness, fullness and so on. In the meantime, the physical and mechanical properties of the finish leather were not less than the common tanning method. Besides, the leather rate significantly increased when the regenerative chrome-tanning agent was used on retanning process.

Applicability of Nanofiltration in the Recovery of Chrome Tanning Wastewater

Applicability of Nanofiltration in the Recovery of Chrome Tanning Wastewater

Bioaccumulation of chromium from tannery wastewater: an approach for chrome recovery and reuse.

The presence of chromium in the effluent is a major concern for the tanning industry. Currently, chemical precipitation methods are practiced for the removal of chromium from the effluent, but that leads to the formation of chrome-bearing solid wastes. The other membrane separation and ion exchange methods available are unfeasible due to their cost. In this study, the removal of chromium from tannery effluent has been carried out using abundantly available brown seaweed Sargassum wightii. Simulated chrome tanning solution was used for the standardization of experimental trials. Various factors influencing the uptake of chromium, viz., quantity of seaweed, concentrations of chromium, pH of the chrome-bearing wastewater, and duration of treatment, have been studied. Chemical modification of the seaweed through pretreatment with sulfuric acid, magnesium chloride, and calcium chloride showed improved uptake of chromium. Langmuir and Freundlich isotherms have been fitted for various quantities of seaweed. The dynamic method of treatment of protonated seaweed with simulated chrome tanning solution at a pH of 3.5-3.8 for a duration of 6 h gave the maximum uptake of about 83%. A similar uptake has been established for commercial chrome tanning wastewater containing the same concentration of chromium. The Sargassum species exhibited a maximum uptake of 35 mg of chromium per gram of seaweed. Fourier transform infrared spectroscopy, energy-dispersive X-ray analysis, and flame photometry studies have been carried out to understand the mechanistic pathway for the removal of chromium. The potential reuse of chromium-containing seaweed for the preparation of basic chromium sulfate (tanning agent) has been demonstrated.

In Situ Hypochlorous Acid Generation for Treatment of Tannery Wastewaters

A method of wastewater treatment was developed by using in-situ production of hypochlorous acid from the soak liquor of tannery for chlorine generation. The hypochlorous acid was produced in an undivided electrolytic cell. The cell contained graphite anode and stainless steel cathode. The hypochlorous acid was utilized for the oxidation of organic matter present in the wastewater. In the case of vegetable tanning wastewater for an initial chemical oxygen demand concentration of 9,600 mg/L, at the end of 120 min of electrolysis, the chemical oxygen demand remaining was 59 mg/L with the residual chlorine concentration and turbidity as 65 mg/L and 3 NTU, respectively, for an optimum current density of 34 mA/cm2. In the case of chrome tanning wastewater, chromium(III) was oxidized to chromium(VI) by the hypochlorous acid produced during electrolysis with a conversion efficiency of 96 ± 3% at a pH range of 2.5–5.5. The resulting chromium(VI) can be converted easily to basic chromium sulphate [(Cr(H2O)5OH)SO4] ...