Abatement of Azo Dye from Wastewater Using Bimetal-Chitosan

We introduce a new adsorbent, bimetallic chitosan particle (BCP) that is successfully synthesized and applied to remove the orange II dye from wastewater. The effects of pH, BCP quantity, and contact time are initially verified on the basis of the percentage of orange II removed from the wastewater. Experimental data reveal that the Cu/Mg bimetal and chitosan have a synergistic effect on the adsorption process of the adsorbate, where the dye adsorption by Cu/Mg bimetal, chitosan alone, and bimetal-chitosan is 10, 49, and 99.5%, respectively. The time required for the complete decolorization of orange II by 1mg/L of BCP is 10 min. The Langmuir model is the best fit for the experimental data, which attains a maximum adsorption capacity of 384.6mg/g.The consideration of the kinetic behavior indicates that the adsorption of orange II onto the BCP fits best with the pseudo-second-order and Elovich models. Further, the simulated azo dye wastewater can be effectively treated using a relatively low quantity of the adsorbent, 1 mg/L, within a short reaction time of 20 min. Overall, the use of BCP can be considered a promising method for eliminating the azo dye from wastewater effectively

Experimental dataforsynthesisofbi-metalized chitosanparticleforattenuatingofanazodye fromwastewater

In thisdataarticle,weintroducedataacquiredfromnewadsor- bent, bi-metalizedchitosanparticlethatissuccessfullysynthesized and appliedtoremovetheorangeIIdye,anazodye,fromtextile wastewater.Theadsorbentwasmeso-andmacro-porousmaterial with BETsurfaceareaof12.69m2/g andpHzpc 6.6. Thesimulated textile-wastewatercanbesignificantly treatedusingarelatively low quantityoftheadsorbent.Overall,theuseofbi-metalized chitosan particlecanbeconsideredapromisingmethodforelim- inating theazodyefromwastewatereffectively.Accordingly,these data willbeusefulfordecolorizingofazodyesfromtextilewas- tewater

Simultaneous biofiltration of BTEX and Hg� from a petrochemical waste stream

A biofiltration system was developed to treat benzene, toluene, ethylbenzene, and xylene (BTEX) and Hg� vapour from a petrochemical waste stream during overhaul maintenance. The biofilter compost bed was inoculated with a microbial consortium provided by a petrochemical wastewater treatment plant. The effect of the a BTEX concentration (192.6e973.8 g/m3h) and empty bed residence time (EBRT) of 20 e100 s were studied under the conditions of steady state, transient, shock BTEX-loading, and off-restart. The findings revealed that during a biofilter start-up, an increase in the influent BTEX concentration to around 334.3 g/m3h did not notably affect the biofiltration function at an EBRT of 100 s, and the removal efficiency was higher than 98%. Further, the low EBRT of 60 s did not have adverse effects on the BTEX and Hg� biofiltration (the removal efficiency in both was >93%). For the biofiltration system, the BTEX and Hg� critical attenuation capacity were obtained as 663 gBTEX/m3h and 12.6 gHg�/m3h respectively. A maximum attenuation capacity of 774.5 gBTEX/m3h was achieved in the biofilter when the BTEX loading rate was 973.8 gBTEX/m3h. The parameters of km and rmax of the MichaeliseMenten kinetic model were obtained as 0.099 g/m3 and 0.578 g/m3min respectively. Both BTEX and mercury vapours were completely mass balanced during a continuous biofiltration test. In general, the developed treatment system exhibited a good performance in the treatment of the BTEX stream containing Hg� vapour in the off-gas of a petrochemical compan

Cadmium elimination from wastewater using potato peel biochar modified by ZIF-8 and magnetic nanoparticle

A recyclable and magnetic nanocomposite was fabricated from biochar of potato peel (BPP), MnFe2O4, and ZIF-8 (BET area: 174.92m2/g). The Cd2+ removal using BPP/MnFe2O4@ZIF-8 was maximized at pH 6, a temperature of 45 °C, and a time of 100 min. The capacity of Cd adsorption using BPP, BPP/MnFe2O4, and BPP/MnFe2O4@ZIF-8 was computed to be 33.76, 45.02, and 80.52 mg/g, respectively. The influence of coexistence ions on cadmium elimination by BPP/MnFe2O4@ZIF-8 was explored. Shipbuilding wastewater was treated to an acceptable level using the nanocomposite. The Cd adsorption was endothermic and followed the pseudo-second-order (R2 > 0.98). Therefore, BPP/MnFe2O4@ZIF-8 is an affordable material for treating cadmium

The correlation of trihalomethanes with other disinfections by-products and fractionation of dissolved organic carbon in Dez River water

This work assesses the correlation between trihalomethanes (THM) and the formation potential (THMFP) of other disinfections by-products and the fractionation of natural organic matter in Dez River water in Iran. The THMFP of Dez River water was well correlated with the haloacetonitriles (R2 = 0.796) and haloacetic acids (R2 = 0.907) formation potential. The most abundant fraction of natural organic matter in the river was hydrophobic acid fraction (49.4 μg/L). The study demonstrated that however the THMFP of Dez River water was relatively high but a usual waterworks could effectively reduce THMFP

Effect of water quality and operational parameters on trihalomethanes formation potential in Dez River water, Iran

This study assesses the influence of the total organic carbon (TOC) content, chlorine quantity, water temperature, bromide ion concentration, and seasonal variations on trihalomethanes (THMs) formation potential (THMFP) in Dez River water in Iran. The water temperature and TOC content had a significant effect on THMFP. Further, the experimental results showed that increasing the concentration of bromide ions enhances the formation of dibromochloromethane and bromoform. It was found that the THMFP in Dez River water during summer times was relatively higher than 100 µg/L, maximum contaminant level for THMs in drinking water. By increasing the reaction time until 80 h, the THMFP was gradually increased and reached to 177.4 µg/L. The most abundant fraction of natural organic matter in the river was hydrophobic acid fraction (49.4 μg/L). Overall, our study demonstrated that however the THMFP of Dez River water was relatively high but a usual waterworks could effectively reduce THMFP

Recent advances in dyes uptake by microplastics in aquatic environments: Influencing factors and ecotoxicological behaviors

Understanding the adsorption mechanisms and interaction of dye pollutants and microplastics in natural water is vital to evaluating potential risks. This review article discusses the bibliometric analysis and the adsorption behavior of dyes to microplastics. The review also examined the impact of environmental (salinity, pH, and temperature) and physicochemical (particle size and active area) factors on dye uptake by microplastics. The maximum amount of Cyan dye adsorbed onto polyethylene microplastics was reported to be 2874.4 mg/g. Polystyrene (PS) microplastics exhibited the highest adsorption capacity for aniline (0.060 mg/g) due to its surface area of 0.7214 m2/g. In 50 % of dye uptake studies on microplastics, the equilibrium condition was reached within 24 h. However, in a few cases, equilibrium was achieved in 8 days. The desorption efficiency of malachite green in the simulated gastric fluid at high temperatures was 81.4 %. The concentration of dyes in the isotherm studies of their adsorption by microplastics varied widely (5–160 mg/L). According to the criterion of R2 > 0.95, the Langmuir isotherm demonstrates a better fit with the data in most of the studies. The lowest uptake of dyes was observed at a pH of 1.5 under the same conditions. Studies have shown that higher temperatures can increase the ability of microplastics to attract and release organic and inorganic pollutants. The potential ecological effects of ‘microplastic-dye’ on organisms and the methods for removing microplastics were investigated. This paper has provided data for the assessment of the potential risks of ‘microplastic-dye’ to aquatic organisms

Characteristics and performance of Cd, Ni, and Pb bio-adsorption using Callinectes sapidus biomass: real wastewater treatment

In the current study, the bio-adsorption potential of Callinectes sapidus biomass for control of cadmium, nickel, and lead from the aqueous stream was assessed. Spectrum analysis of FTIR, AFM, EDAX, mapping, SEM, TEM, and XRF was used to study the properties of the C. sapidus biomass. The XRF analysis revealed that C. sapidus bio-adsorbent has various effective metal oxides that can be useful to adsorb pollutants. The best model to describe the equilibrium data was Freundlich isotherm. The Langmuir bio-adsorption capacity was reported at 31.44 mg g −1 , 29.23 mg g −1 , and 29.15 mg g −1 for lead, cadmium, and nickel ions, respectively. Pseudo-first-order and pseudo-second-order kinetic models were studied to test the kinetic behavior of the process. An intra-particle diffusion model was used to determine the effective mechanisms involved in the bio-adsorption. Based on t 1/2 , it can be concluded that the equilibrium speed of the bio-adsorption process is high. The thermodynamic study showed that the metal bio-adsorption process using C. sapidus biomass is exothermic and spontaneous. The field applicability of the crab bio-adsorbent for eliminating concurrently several contaminants (metal ions, antibiotics, sulfate, nitrate, and ammonium) from an actual wastewater was successfully examine

Marine litter along the shores of the Persian Gulf, Iran

Plastic wastes —including cigarette butts (CBs)— are dangerous for marine ecosystems not only because they contain hazardous chemicals but also because they can finally turn into micro- or even nano-particles that may be ingested by micro- and macro-fauna. Even large pieces of plastics can trap animals. In this research, the pollution status of macroplastics (abundance, size, type, and colour) and cigarette butts (CBs, number/m2) on the northern coasts of the Persian Gulf has been investigated. A total of 19 stations were explored in Bushehr province (Iran), which covers a length equivalent to 160 km of the Persian Gulf coastline. Among the collected plastic waste (2992 items), disposable mugs were the most frequent (18 %). Plastics with sizes 5–15 cm were the most abundant, and the most common type of plastic was PET (P-value <0.05). The origin of most macroplastics was domestic (2269 items). According to the Index of Clean Coasts (ICC), most surveyed beaches were extremely dirty. The average number and density of CBs in this study were 220 and 2.45 items/m2, respectively. Household litter was the most abundant type of waste in the studied beaches, and this problem can be better managed by training and improving the waste disposal culture. In general, it is suggested that an integrated and enhanced management for fishing, sewage and surface water disposal, and sandy recreational beaches be implemented in Bushehr to control plastic waste