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Water is one of the most important components in the environment. This is essential for all forms of life and leisurely plays a vital role in the world economy. The discharge of large amount of dye wastewater from different industries such as textile, leather, pulp, rubber pharmaceuticals, food processing, electroplating cosmetics, plastic, paper industries, etc. to the aquatic system constitutes the major hazards to the living environment. Hence, the rapid removal of these dyes from wastewater before their discharge is an important necessity of day to day life as well as for environmental safety. Several traditional treatment methods were available for the removal of dyes from water/wastewater such as chemical coagulation, filtration, flocculation, ozonation, oxidation, photocatalytic degradation, ion exchange, biodegradation, electrolysis and adsorption. Among all these treatment methods, adsorption process using activated carbon is one of the most important, effective and reliable method for the removal of dyes from aquatic system. However, the widespread application of activated carbon is restricted because of its high cost. Therefore, the attention has moved to select the low-cost and efficient adsorbents which are alternative to the existing activated carbon. Some of the natural materials, agricultural wastes, industrial wastes and biosorbents have been reported as an effective low-cost adsorbent for the removal of dyes from aquatic system by many researchers. The current review paper explains the detailed survey on the dye removal methods, and scope for the improvement can be done on the removal of dyes from industrial wastewater. [ABSTRACT FROM AUTHOR]

Dairy products are one of the richest sources of vital nutrients in the diet of human beings and it occupies an important place in satisfying their nutrient requirements. The dairy products possess a very short lifespan and during their decomposition create a huge nuisance to the environment. The dairy effluents discharged from the industries are mainly composed of complicated substances such as organic compounds, inorganic compounds, carbon, nitrogen, phosphorus, chlorides, sulphides, fats, oils, grease, etc. These organic loading present in the dairy effluent have a negative impact on the environment during its discharge to nearby water sources. The physical and chemical treatment of the dairy effluents is not as effective as the biological treatment. The biological treatment method is found to be the superior method for treating the dairy effluent. The biological wastewater treatment can be performed in two various conditions such as aerobic and anaerobic. The treatment methods such as aerobic lagoons, activated sludge, sequential batch reactor, trickling filter, completely stirred tank reactors, fluidized bed reactors, and anaerobic filters are some of the biological methods used in dairy effluent treatment. This review article has investigated in detail regarding the environmental impact of dairy effluents and their effective treatment using biological treatment technologies. [ABSTRACT FROM AUTHOR]

In the current research work, the activated carbon synthesized from the plant species Delonix regia is doped with iron oxide nanoparticles and enforced as a nanosorbent for the effective extermination of Tartrazine (TAR) and Methylene blue (MB) dyes. This nanosorbent is prepared from the bark powder of the Delonix regia and subjected to chemical activation; Furthermore, the synthesized biosorbent were characterized using FTIR, SEM, TGA, and XRD to understand their functional properties and structural morphology. The optimum effectiveness adsorption of Tartrazine and Methylene blue has been investigated by using different key parameters. The conclusions have shown the highest removal percentage at a pH of 3 and 6 for Tartrazine and Methylene blue, respectively. For the various initial concentrations, the adsorption percentage reached equilibrium after 60 min and 90 min for TAR and MB. The adsorption equilibrium values were applied to various isotherms models. The adsorbent showed a higher removal capacity of 357.142 mg g−1 and 147.058 mg g−1 and for MB and TAR respectively. The kinetic data were best fits to pseudo second order model. The thermodynamic parameters indicated that this adsorption process was found to be spontaneous, exothermic and feasible at different temperatures. These results have shown that the prepared adsorbent is an environmentally friendly and suitable material for the elimination of TAR and MB from water systems. [ABSTRACT FROM AUTHOR]

In this present study, tin (Sn) doped MnFe 2 O 4 (Sn 0.15 Mn 0.85 Fe 2 O 4) nanocomposites were synthesized using a microwave combustion method by employing Alocasia odutra plant extract as a natural fuel. Sn is well incorporated with spinel ferrite (MnFe 2 O 4) which is confirmed by XRD analysis. FE-SEM analysis indicates that the synthesized sample having a rod-like structure in nature. The emerging pharmaceutical contaminant, namely, diclofenac (2-(2-(2,6-dichlorophenylamino)phenyl) acetic acid) (DCF), the non-steroidal anti-inflammatory drug was utilized as a model pollutant to evaluate the catalytic efficiency of the Sn 0.15 Mn 0.85 Fe 2 O 4 (SMF) under solar irradiation. SMF shows higher catalytic activity than pristine MnFe 2 O 4 due to a reduction in the bandgap energy from 1.78 eV to 1.54 eV as a result of Sn doping into MnFe 2 O 4. The degradation efficiency of DCF using the SMF catalyst was found to be 99% in a shorter interval (50 min) with 71% mineralization. Radical trapping experiments indicate that the photo-generated holes and hydroxyl radicals actively participate in the degradation process of DCF using the SMF catalyst. The optimum pH for the removal of DCF using the SMF catalyst was found to be 4 with the catalyst dosage of 0.8 g/L. The recycling experiment shows that the SMF catalyst has high stability up to five cycles and low iron leaching ability under optimum conditions. Sn 0.15 Mn 0.85 Fe 2 O 4 catalyst can be recovered using an external magnet from the reaction mixture and it is recycled. It was concluded that the synthesized catalyst can be used as a tertiary treatment option for the removal of emerging pharmaceutical pollutants. ga1 • SMF nanoparticles was synthesized via microwave assisted combustion method using Alocasia odutra plant extract. • 71% mineralization of DCF was achieved within 50 min in the presence of sunlight. • SMF has more stability and low iron leaching capacity. • Efficiency of SMF were tested against different water matrices. • The carbonate ions and humic acid in water competes with the active radicals declined the catalytic activity of SMF. [ABSTRACT FROM AUTHOR]

In the current research work, a novel eco-friendly Fe 3 O 4 @SiO 2 nanocomposite immobilized with Pseudomonas fluorescens biomass in calcium alginate beads (MSAB) was used as biosorbent for the elimination of hazardous Rhodamine B dye from aqueous system. The FTIR, XRD and SEM results showed that the MSAB possessed excellent surface properties for the effective sequestration of Rhodamine B. The batch adsorption results concluded that the adsorption of Rhodamine B using MSAB is highly influenced by the parameters such as pH, adsorbent dosage, initial dye concentration and contact time. The equilibrium and kinetics data get best fitted in the Freundlich isotherm and Pseudo first order kinetics for the studied adsorption system. The Langmuir monolayer adsorption capacity was found to be 229.6 mg/g. The thermodynamic studies showed that the adsorption was spontaneous, feasible and exothermic in nature. The adsorption mechanisms are understood using the Intraparticle diffusion and Boyd model. Thus, this Magnetic silica alginate beads (MSAB) containing dead biomass of Pseudomonas fluorescens is considered to be an ideal biosorbent which can be used as an effective tool in treating the industrial dye wastewater treatment. Image 1 • Pseudomonas fluorescens was successfully incorporated in the magnetic silica. • MSAB biosorbent is eco-friendly in nature. • Adsorbent can be easily recovered using an external magnetic field. • The maximum monolayer adsorption capacity is found to be at 229 mg/g. • This adsorbent can reduce the secondary pollution. Main Finding: The effective separation of toxic dye from aqueous system was achieved using Magnetic Silica Nanocomposite Immobilized Pseudomonas fluorescens. [ABSTRACT FROM AUTHOR]

The objective of the current study was focused on the potential adsorption capability of a biogenic hydroxyapatite/iron nanoparticles-based composite tailored for the elimination of toxic pollutant, Cd(II) ions. Morphological along with physicochemical properties of composites were analyzed by different techniques including Scanning electron microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDAX), X-ray diffraction (XRD), and Fourier Transform Infrared Spectroscopy (FTIR). It has been noticed an increase in cell parameters of prepared composites with an increase in the amount of nanoparticles. The best adsorbent was found to be the one with a 5% amount of nanoparticles (P 400 F e (5%)). The kinetics studies have shown that the pseudo-first-order-models were in good agreement for the removal of Cd(II) ions onto P 400 Fe(5%) at any concentration, suggesting a physisorption mechanism. Besides, isotherms analysis has consistently revealed Freundlich as the model better explained the isotherm data, with a maximum removal capacity of 392.3 mg g−1, higher compared to many adsorbents. Thermodynamically, the removal adsorption process of Cd(II) ions onto the composite favorable, exothermic, and spontaneous. The regeneration study has been also investigated with reusability used until four cycles. The overall results pointed out the suitability and efficiency of the prepared biogenic composite for the elimination of metal pollutants in wastewater. [Display omitted] • Biogenic composites were successfully prepared from slaughterhouses by-product and iron nanoparticles. • The maximum adsorption capacity of P 400 Fe(5%) was up to 392.3 mg g−1. • The isotherm and kinetic data best fits Freundlich and pseudo-first-order models. • The mechanism could be due to cationic exchange between Ca2+ and Cd2+. • The biogenic composite was effective for four consecutive regeneration cycles. [ABSTRACT FROM AUTHOR]