Removal of copper from aqueous solution by Ascophyllum nodosum immobilised in hydrophilic polyurethane foam.
The seaweed Ascophyllum nodosum was pre-treated by successive washes in distilled water and dilute acid, dried, and pulverised to produce particles of <150 microm. These were immobilised during the manufacturing process of Hypol 2002 polymer to form a biomass/polymer matrix that was stable and easy to handle. In making the composite a mixing speed of 360 rpm for 20-30 s with 2% (w/w) addition of surfactant to pre-polymer was found to be ideal. The average pore sizes for different water polymer mixes (expressed as volume ratios) were 1.66 mm +/- 0.98 (ratio 0.75:1), 1.58 mm +/- 0.76 (ratio 1:1), 1.64 mm +/- 0.6 (ratio 1.5:1) and 1.11 mm +/- 0.615 (ratio 2:1). The biomass/polymer was used alongside free native biomass in an initial adsorption experiment using a 0.0315 mmol dm(-3) Cu (II) solution and gave a copper uptake capacity (q)(max) of 0.037 mmol Cu g(-1) dry weight seaweed in both cases which represented approximately 85% of total initially available copper. In later adsorption isotherm experiments using Cu concentrations between 0.0315 and 0.944 mmol dm(-3) at pH 5.0 and immobilized biomass over five consecutive adsorption/desorption cycles the biomass/polymer showed an initial lowering of adsorption capacity but stabilised at 0.23 mmol g(-1) dry weight by the third re-use. The q(max) of the immobilised biomass decreased from 0.55 and 0.416 mmol of Cu g(-1) dry weight when pH was lowered from 4.0 to 3.0, and increased from 0.576 mmol g(-1) dry weight (biomass) at 283 K to 0.636 mmol g(-1)(biomass) at 303 K.
Department of Civil and Environmental Engineering, University of Southampton, Southampton, SO17 1BJ, UK.
M S
MS
Alhakawati
C J
CJ
Banks
D000327:Adsorption; D044646:Ascophyllum / Q000737:chemistry* / Q000502:physiology*; D001673:Biodegradation, Environmental; D018533:Biomass; D003252:Construction Materials; D003300:Copper / Q000302:isolation & purification*; D011108:Polymers; D011140:Polyurethanes; D014873:Water Pollutants / Q000302:isolation & purification*
D011108:Polymers; D011140:Polyurethanes; D014873:Water Pollutants; D003300:Copper; C028279:polyurethane foam