Magnetic nanocellulose from Cyperus rotundas grass in the absorptive removal of rare earth element cerium (III): Toxicity studies and interpretation.

In this study a very common grass named Cyperus rotundas was used to extract cellulose which was converted to magnetic grass nano cellulose (MGNC) to adsorb rare earth element Cerium (Ce (III)). The prepared MGNC was analyzed with sophisticated technique to determine the alteration in physical and chemical properties before and after adsorption with the pollutant Cerium. Parameters like pH, temperature, MGNC dosage and initial concentration of Ce were optimized to check parameters influencing the adsorption of Ce (III). The optimized experimental data were perfectly modelled into Langmuir model with adsorption capacity of 353.04 mg g -1 for Ce (III). For kinetics the data fitted into pseudo second order model. To check the efficacy of MGNC in real scenario, untreated and treated Ce was used for phototoxicity studies with 4 different plant seeds. Apart from this, model fish, Danio rerio was used to check the toxicity level on aquatic organism before and after adsorption of Ce (III) with MGNC. This study showed the efficient use of MGNC and maximum removal of Cerium from wastewater and the magnetic behavior incorporated adds advantage of easy retrieval.

Development of Fe3O4/CAC nanocomposite for the effective removal of contaminants of emerging concerns (Ce3+) from water: An ecotoxicological assessment.

Contaminants of emerging concerns present in the ecosystems causes various adverse effects on all living organisms. In current study, removal of Ce3+ from water was performed using Fe3O4/CAC nanocomposite (MCAC) synthesized by co-precipitation technique. The synthesized MCAC was characterized using various analytical techniques. The magnetic behavior of the nanocomposite which is a crucial advantage in separation of MCAC after adsorption of Ce3+ from water was determined using vibrating sample magnetometer. MCAC was polycrystalline comprising both amorphous and crystalline regions with elements like C, O, Fe and N. The influence of process parameters was optimized through batch mode with the adsorption capacity of 86.206 mg/g. Ecotoxicological studies were performed using Danio rerio (Zebra fish) and seeds of Vigna mungo and Vigna radiata to assess the harmful effects of Ce3+ before and after adsorption process. The phytotoxicity studies on seeds revealed that inhibition of growth ranges from 50.39% to 12.55% (before adsorption) and 28.57%-3.89% (after adsorption). After 96 h the LC50 value of Ce3+ on the Danio rerio before and after adsorption was 2.44 and 77.85 mg/L. Thus, the current study investigated the effective removal of Ce3+ by MCAC and evaluates its ecotoxicological effects.

Ecotoxicological assessment of micropollutant Diclofenac biosorption on magnetic sawdust: Phyto, Microbial and Fish toxicity studies.

Diclofenac (DCF), a persistent pharmaceutical micropollutant which occurs in the ecosystems causing adverse effects on aquatic as well as terrestrial organisms. In this study, magnetic sawdust (MSD) was prepared using co-precipitation method for biosorptive removal of DCF from water. The MSD was characterized using various analytical techniques like microscopic and spectroscopic analysis. Magnetometer study confirms the ferromagnetic behavior of the biosorbent which is a key advantage in the separation of MSD after biosorption. The effect of experimental parameters was optimized in batch mode with evaluated maximum efficiency of 86.12 % at pH 6, biosorbent dosage 25 mg for 50 mg/L of DCF. Ecotoxicological assessment has been performed for the treated and untreated sample using plant seeds, microbes and zebra fish to check the adverse effects of DCF on these organisms. Evaluation of toxicity studies revealed that inhibition concentration of DCF for various seeds (60.91 mg/L to 43.11 mg/L), E. coli (48.82 µg/mL) and B. subtilis (31.55 µg/mL). The lethal concentration of DCF on the Danio rerio was found to be 156.99 mg/L. In contrast, significant increase in both the concentration measures of DCF after biosorption was observed making this biosorbent a potent alternative to other available treatment measures.

Use of Nanocellulose extracted from grass for adsorption abatement of Ciprofloxacin and Diclofenac removal with phyto, and fish toxicity studies.

The present study deals with the adsorption of antibiotic Ciprofloxacin (CPXO) and anti-inflammatory agent Diclofenac (DCF) on Grass nanocellulose (GNC) extracted from Cyprus rotundas grass. The adsorbent GNC was characterised using various microscopic, elemental and spectroscopic analysis to monitor the physicochemical alterations of the surface before and after adsorption. The size of the converted nanocellulose was found to be 40-50 nm. The experimental measures influencing the adsorption of CPXO and DCF that were optimised are initial solution pH, GNC dosage, temperature and initial concentration of the adsorbate. Halsey isotherm model and pseudo-second order kinetic model agreed best with the experimental outcome for both the adsorbate. The maximum adsorption capacity of GNC were 227.223 and 192.307 mg/g for CPXO and DCF respectively. Phytotoxicity studies were performed using 6 different types of seeds to evaluate the effect of GNC treated effluent on plants. Similarly, acute fish toxicity on zebra fish analysis showed to have lesser mortality rate of the effluent after adsorption of CPXO and DCF on GNC.