Biosynthesised magnetic iron nanoparticles for sludge dewatering via Fenton process

• Published in: Environmental science and pollution research international 2016-11, Vol.23 (21), p.21416-21430
• Main Authors: Ealias, Anu Mary, Jose, Jephin Varughese, Saravanakumar, M. P.
• Format: Article
• Language: English
• Subjects: Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Biopolymers; Biosynthesis; Bound water; Calorimetry; Catalysis; Chemical Precipitation; Cinnamomum; Cinnamomum - chemistry; Dewatering; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Filtration - methods; Fourier transforms; Heavy metals; Hydrogen peroxide; Hydrogen Peroxide - chemistry; Infrared spectroscopy; Investigations; Iron - chemistry; Leaves; Magnetics; Nanocatalysis; Nanoparticles; Nanoparticles - chemistry; Oxidation-Reduction; Particle size; Phytochemicals; Plant Extracts - chemistry; Polyphenols; Research Article; Saccharides; Sewage - chemistry; Sludge; Sludge drying; Sludge treatment; Spectrum analysis; Studies; Surface Properties; Transmission electron microscopy; Waste Water Technology; Water content; Water Management; Water Pollutants, Chemical - isolation & purification; Water Pollution Control; Water treatment; X-ray diffraction
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-016-7351-4

The magnetic iron nanoparticles (MFeNp) were biosynthesised using the extract of Cinnamomum tamala (bay leaf) and examined for its efficacy on sludge dewatering. The characteristics of MFeNp were studied using scanning electron microscope (SEM), transmission electron microscopy (TEM), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and x-ray photoelectron spectrometer (XPS) techniques. The presence of polyphenolic compounds were confirmed by FTIR and XPS analysis. The reduction in capillary suction time (CST) (71.36 to 16.5 s) and specific resistance to filtration (SRF) (53.71 × 10 11 to 1.47 × 10 11  m/kg) values have indicated that the use of Fenton nanocatalyst enhanced the sludge dewaterability. The differential scanning calorimetry (DSC) analysis has shown that the mass of bound water in the treated sludge was decreased significantly from 1.45 to 0.92 kg H 2 O/kg DS. The breakdown of extracellular polymeric substances (EPS) by the MFeNp leads to the significant reduction in proteins, polysaccharides, water content and heavy metals. The optimisation using response surface modelling (RSM) have shown that the maximum removal efficiency of water from the sludge was 85.9 % when the optimum pH (3) MFeNp dosage (50 mg/g DS) and H 2 O 2 dosage (500 mg/g DS) were maintained. The experimental results and the statistical optimisation have suggested that MFeNp can be used as a potential nanocatalyst for the sludge dewaterability and hence it can be used for the agricultural purpose. Graphical abstract Schematic representation of sludge dewatering process