Removal of Levofloxacin from aqueous solution by Magnesium-impregnated Biochar: batch and column experiments

<p>Adsorption of levofloxacin (LEV) onto four types of magnesium (Mg)-impregnated biochars, fabricated via thermal pyrolysis of wood chips pretreated with MgSO₄ was investigated. The Mg-impregnated biochars were characterized with various tools and techniques. Batch sorption experiments were conducted to determine the sorption kinetics and isotherms of LEV onto the Mg-impregnated biochars. The pseudo-second order kinetic model described the adsorption kinetic data better than the pseudo-first order kinetic model and the Elovich equation. Due to multi-mechanisms, the Freundlich model described the experimental isotherms better than the Langmuir model. The Langmuir maximum adsorption capacities of the Mg-impregnated biochars to LEV ranged from 7.38 to 25.2 mg g⁻¹. In the fixed-bed column experiment, higher bed height and lower flow rate led to greater LEV removal. Findings from this work indicate that Mg-impregnated biochars can be used as an alternative adsorbent to effectively remove LEV from aqueous solutions.</p

Immunogold labeling of dehydrin protein in loquat fruitlets.

<p>A) ‘FS-NHB’ before freezing stress; B) ‘FT-JJ’ before freezing stress; C) ‘FS-NHB’ after freezing stress; D) ‘FT-JJ’ after freezing stress. CW, cell wall; the arrow indicates the dense labeling on the plasma membrane; Bar  =  0.5 µm.</p

Primers used for Q-PCR amplification.

<p>Primers used for Q-PCR amplification.</p

Physiological changes in ‘FS-NHB’ and ‘FT-JJ’ fruitlets during freezing treatment.

<p>A) O₂^{. −} generation rate; B) H₂O₂ content; C) MDA content; D) SOD activity; E) APX activity; F) CAT activity. The data were presented as the mean ± SE (n  =  3).</p

Leakage of electrolytes in loquat fruitlets from ‘FS-NHB’ and ‘FT-JJ’ when treated with temperatures below freezing.

<p>The data were presented as the mean ± SE (n  =  3).</p

Expression patterns of <i>EjDHN</i> genes in ‘FS-NHB’ and ‘FT-JJ’ fruitlets during freezing treatment.

<p>The level of actin expression was used to normalize the mRNA levels in each sample, and mRNA levels produced by Q-PCR are expressed relative to actin levels. The data were presented as means mean ± SE (n  =  3).</p

Alignment of multiple EjDHN amino acid sequences.

<p>Conserved amino acid sequences are indicated by pink boxes for the Y-segment; blue boxes for the S-segment; and red boxes for the other Y-segment.</p

Characteristics of loquat DHN protein sequence features.

<p>Characteristics of loquat DHN protein sequence features.</p

Phylogenetic analysis of dehydrin proteins from loquat, apple, <i>Arabidopsis thaliana</i>, and barley.

<p>An unrooted tree was generated using the MEGA5.0 program and neighbor-joining method. Proteins were arranged into classes I, II, III, and IV based on sequence similarities. GenBank accession numbers are as follows: seven loquat (<i>Eriobotrya japonica</i>; Ej) dehydrins including EjDHN1 (FJ472835), EjDHN2 (FJ472836), EjDHN3 (KF277187), EjDHN4 (KF277188), EjDHN5 (KF277189), EjDHN6 (KF277190), and EjDHN7 (KF277191); nine apple (<i>Malus domestica</i>, Md) dehydrins including MdDHN1 (JQ649456), MdDHN2 (JQ649457), MdDHN3 (JQ649458), MdDHN4 (JQ649459), MdDHN5 (JQ649460), MdDHN6 (JQ649461), MdDHN7 (JQ649462), MdDHN8 (JQ649463), and MdDHN9 (JQ649464); ten <i>Arabidopsis thaliana</i> (At) dehydrins including At1g20440 (AY11 4699), At1g20450 (AF360351), At1g54410 (NM_104319), At1g 76180 (AF339722), At2g21490 (BT000900), At3g50970 (NM_114957), At3g50980 (NM_114958), At4g38410 (NM_120003), At4g39130 (NM_120073), and At5g66400 (AY093779); and thirteen barley (<i>Hordeum vulgare</i>, Hv) dehydrins including HvDHN1 (AF043087), HvDHN2 (AF181452), HvDHN3 (AF181453), HvDHN4 (AF181454), HvDHN5 (AF181455), HvDHN6 (AF181456), HvDHN7 (AF181457), HvDHN8 (AF181458), HvDHN9 (AF181459), HvDHN10 (AF181460), HvDHN11 (AF043086), HvDHN12 (AF155129), and HvDHN13 (AY681974).</p

Immunogold labeling density of EjDHNs in fruitlets of ‘FS-NHB’ and ‘FT-JJ.’

*<p>Values are expressed as mean ± SE (n  =  5). Values followed by different letters are significantly different at <i>p</i><0.05.</p