Degradation Of Industrial Effluents Research Articles

Suspended and Coated Iron Waste for Photo-Fenton-Like Degradation of Industrial Effluents under Neutral Condition

The iron waste collected from steel workshop was evaluated as a catalyst in heterogenous photo-Fenton like process. The analyses such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were carried out to assess the morphology, chemical structure and chemical composition of the iron waste. The degradation efficiency of methylene blue (MB) went up from 81.4% in dark to 90.4% in light in the case of iron loading of 0.5 g/100 mL, persulfate (PS) concentration of 0.1 mM, MB concentration of 10 mg/L and pH 7. The uppermost degradation efficiency of MB was accomplished at pH 3 and the raising of PS concentration above 0.25 mM reduced the removal efficacy of MB. The degradation percentage of MB declined in the case of iron loading higher than 1.0 g/100 mL. The degradation rates of MB decreased with the rise of initial MB concentration. The degradation efficiencies of MB were 68.8%, 67.3%, 64.3%, 63% and 60% in five consecutive runs and the degradation efficiencies of pharmaceutical wastewater were 36.55%, 35.69%, 34.24%, 33.4% and 32% using the iron coated plates. The degradation ratios of agrochemical wastewater were 40.76%, 38.6%, 37.5%, 36.1% and 34.98%, whereas they were 23.7%, 22.35%, 22.03%, 21.23% and 20.03% in the case of petrochemical wastewater in five successive runs using the immobilized plates.

Green Biosynthesis of Tin Oxide Nanomaterials Mediated by Agro-Waste Cotton Boll Peel Extracts for the Remediation of Environmental Pollutant Dyes.

The sustainable synthesis of metal oxide materials provides an ecofriendly and more exciting approach in the domain of a clean environment. Besides, plant extracts to synthesize nanoparticles have been considered one of the more superior ecofriendly methods. This paper describes the biosynthetic preparation route of three different sizes of tetragonal structure SnO2 nanoparticles (SNPs) from the agro-waste cotton boll peel aqueous extract at 200, 500, and 800 °C for 3 h and represents a low-cost and alternative preparation method. The samples were characterized by X-ray diffraction, Fourier transform infrared spectrophotometry, ultraviolet–visible absorption spectroscopy, high-resolution transmission electron microscopy (HR-TEM), and energy-dispersive X-ray spectroscopy. Surface area and porosity size distribution were identified by nitrogen adsorption–desorption isotherms and Brunauer–Emmett–Teller analysis. The photocatalytic properties of the SNP samples were studied against methylene blue (MB) and methyl orange (MO), and the degradation was evaluated with three different size nanomaterials of 3.97, 8.48, and 13.43 nm. Photocatalytic activities were carried out under a multilamp (125 W Hg lamps) photoreactor. The smallest size sample exhibited the highest MB degradation efficiency within 30 min than the most significant size sample, which lasted 80 min. Similarly, in the case of MO, the smallest sample showed a more superior degradation efficiency with a shorter period (40 min) than the large-size samples (100 min). Therefore, our studies suggested that the developed SNP nanomaterials could be potential, promising photocatalysts against the degradation of industrial effluents.

Highly efficient photocatalytic degradation of hazardous industrial and pharmaceutical pollutants using gadolinium doped BiFeO3 nanoparticles

This investigation highlights the synthesis of an efficient photocatalyst, 10% gadolinium (Gd) doped BiFeO3 (BGFO) nanoparticles, via a facile hydrothermal technique at a lower reaction temperature of 160 ∘C and its effective application towards the degradation of industrial effluents, such as rhodamine B (RhB), methylene blue (MB) and pharmaceutical pollutants such as ciprofloxacin (CIP), levofloxacin (LFX) under solar irradiation. The successful fabrication of the photocatalyst was confirmed by the Rietveld refined powder X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy analyses. The high resolution transmission electron microscope imaging demonstrated the formation of nanoparticles with excellent morphology and very good crystallinity. The optical characterizations revealed a reduction in the optical band gap from 1.95 to 1.18 eV, as well as effective suppression of electron-hole pair recombination in the BGFO sample. Notably, the photocatalyst BGFO demonstrated 96% and 97% degradation of RhB and MB within 240 and 180 min of solar irradiation, respectively. Moreover, the photodegradation of colorless organic contaminants CIP and LFX was also examined to evaluate the photosensitization properties. Interestingly, about 80% and 79% degradation of CIP and LFX was obtained within 240 min of solar irradiation. The enhanced photocatalytic activities of BGFO could be attributed to the excellent morphology, good crystallinity, increased optical absorption, and effective separation of the photogenerated charge carriers. Additionally, based on the band structures, a plausible mechanism was proposed to comprehend the rationale behind the influential photocatalytic performance of the synthesized nanoparticles to explore their potential towards the future of wastewater treatment on an industrial scale.

Purification, Biochemical Characterization and Decolorization Efficiency of Laccases from Peach and Cherry Cultures of Pleutorus eryngii: A Comparative Study.

Laccases (Lacs) are used potentially in industrial and biotechnological applications such as decolorization of dyes, degradation of industrial effluents, delignification, etc. thanks to their large varieties of substrate specificities and excellent catalytic efficiencies. The efficient utilizations of Lacs in these applications mostly depend on the identifying their biochemical properties. The goal of this research is to investigate the purification, biochemical characterization and decolorization efficiencies of Lacs. Pleurotus eryngii was incubated on peach (PC) and cherry (CC) wastes under optimized solid state fermentation conditions. Then, the enzymes extracts were purified by ammonium sulfate precipitation, anion exchange chromatography, gel filtration, respectively. Lacs fractions were subjected to electrophoretic analyses as well as their structural and kinetic characteristics. Also, the effects of selected chemical agents on purified Lacs activities and determination of decolorization efficiencies were studied. As the results of purification processes of Lacs from both cultures, 3.94-fold purification was obtained for PC, while it was 5.34 for CC. The electrophoretic results of purified Lacs illustrated the single bands of protein (30±1 kDa) in accordance with the results after gel filtration. The Km values of Lacs from PC and CC were respectively detected as 1.1381 and 0.329 mM for ABTS. The selected agents partially/completely inhibited Lac activities. The highest decolorization efficiencies of purified Lacs from PC and CC were separately obtained as 53 and 11.8%. The results clearly indicated that the performances of Lacs from both cultures in decolorization application are different from each other depending their activities, biochemical and kinetic characteristics.

Optimisation of radiolysis of Reactive Red 120 dye in aqueous solution using ionising (60)Co gamma radiation by response surface methodology.

In recent years, employing radiation technology is gaining great interest in degradation of industrial effluents. In this work the possibility of using gamma irradiation to degrade Reactive Red 120 (C.I.292775) was explored. The effects of pH, dose of gamma irradiation and concentration of dye were examined and their interaction were also established based on their response. For the analysis and optimisation of variables, three factor three level Box-Wilson face centred central composite design (CCF) was used. Analysis of variance with R(2) = 0.9988, adjusted R(2) = 0.9981 and the adequate precision value of 122.303 indicates that the CCF model can be used. The coefficient of variation (0.54%) indicates the reliability of the model. The dose of gamma irradiation (kGy) and the concentration of dye (mg/L) showed significant effects on the degradation of RR 120, while a difference of 6 to 10% degradation was observed in extending the pH towards the acid or alkali range from pH 7.00. The maximum concentration of dye degraded was observed as 347.509 mg/L at initial pH: 7.0, dose of gamma irradiation: 5.94 kGy and initial concentration of dye: 500 mg/L. This predicted value was found to be in agreement with the experimental value on the optimised conditions.

Lignin Degradation:A Microbial Approach

Lignin is the most structurally complex carbohydrate consisting of various bilogically stable linkages. It has been estimated that lignin constitutes 30-35% of the earth's non-fossil organic carbon. Lignin degradation plays an important role in carbon recycling and biofuel production. Industrial waste treatment through chemical approaches is not only expensive but also toxic to environment. Lignin degrading enzymes from microbes contribute a major role in the degradation of industrial effluents. Fungi and bacteria are good sources of effluent hydrolyzing enzymes such as lignin peroxidase, laccase, manganese peroxidase etc. However, there are very few research activities regarding role of microbes in lignin degradation. Lignin hydrolysis using various microbes with eco-friendly approach is a challenge for researchers globally. Therefore, in order to reduce the adverse effect of industrial effluent on environment, the quest for inexpensive, sustainable and eco-friendly approach is indispensable. The current review focuses to enlighten a comprehensive and broad analysis of lignin degradation ability of various fungal and bacterial sources using their ligninolytic machinery system.

High-quality permanent draft genome sequence of the extremely osmotolerant diphenol degrading bacterium Halotalea alkalilenta AW-7(T), and emended description of the genus Halotalea.

Members of the genus Halotalea (family Halomonadaceae) are of high significance since they can tolerate the greatest glucose and maltose concentrations ever reported for known bacteria and are involved in the degradation of industrial effluents. Here, the characteristics and the permanent-draft genome sequence and annotation of Halotalea alkalilenta AW-7T are described. The microorganism was sequenced as a part of the Genomic Encyclopedia of Type Strains, Phase I: the one thousand microbial genomes (KMG) project at the DOE Joint Genome Institute, and it is the only strain within the genus Halotalea having its genome sequenced. The genome is 4,467,826 bp long and consists of 40 scaffolds with 64.62 % average GC content. A total of 4,104 genes were predicted, comprising of 4,028 protein-coding and 76 RNA genes. Most protein-coding genes (87.79 %) were assigned to a putative function. Halotalea alkalilenta AW-7T encodes the catechol and protocatechuate degradation to β-ketoadipate via the β-ketoadipate and protocatechuate ortho-cleavage degradation pathway, and it possesses the genetic ability to detoxify fluoroacetate, cyanate and acrylonitrile. An emended description of the genus Halotalea Ntougias et al. 2007 is also provided in order to describe the delayed fermentation ability of the type strain.

Agroforestry waste Moringa oleifera petals mediated green synthesis of gold nanoparticles and their anti-cancer and catalytic activity

Stable gold nanoparticles (AuNPs) were synthesised from aqueous 1M chloroauric acid and Moringa oleifera flower aqueous extract. The UV–vis spectrum of AuNPs displays the surface plasmon resonance at 540nm. The AuNPs were characterized using transmission electron microscopy, scanning electron microscopy, energy dispersive X-ray analysis and dynamic light scattering whilst Fourier transform infrared and 1H-NMR spectroscopy were used to probe the type of capping agents. The AuNPs were assessed for their catalytic reduction of nitrophenol and nitroaniline by UV–vis and showed a rapid reduction within 3min thereby indicating degradation of industrial effluents. Furthermore, the AuNPs may possess good anti-cancer properties.