Sorption of Paraquat and 2,4-D by an Oscillatoria Sp.-Dominated Cyanobacterial Mat |
| |
Authors: | Dhananjay Kumar Bhanu Prakash Lalit K Pandey and J P Gaur |
| |
Institution: | (1) Laboratory of Algal Biology, Department of Botany, Banaras Hindu University, Varanasi, 221 005, India; |
| |
Abstract: | The present study characterises sorption of two pesticides, namely, paraquat (PQ) and 2,4-dichlorophenoxyacetic acid (2,4-D)
by an Oscillatoria sp.-dominated cyanobacterial mat. Sorption of PQ onto the test mat was not significantly affected by the pH of the solution
within the pH range 2–7. However, 2,4-D sorption was strongly influenced by the solution pH and was maximum at pH 2. Whereas
PQ sorption increased with increase in temperature, 2,4-D sorption showed an opposite trend. The sorption of PQ and 2,4-D
achieved equilibrium within 1 h of incubation, independent of concentration of pesticide and mat biomass in the solution.
The pseudo-second-order kinetic model better defined PQ sorption than the pseudo-first-order model, whereas 2,4-D sorption
was well defined by both the models. Sorption isotherms of both the pesticides showed L-type curve. Freundlich model more
precisely defined PQ sorption than Langmuir model, thereby suggesting heterogeneous distribution of PQ binding sites onto
the biomass surface. However, the Langmuir model more correctly defined 2,4-D sorption, thus, indicating homogeneous distribution
of 2,4-D binding sites onto the biomass surface. The test biomass is a good sorbent for the removal of PQ because it could,
independent of pH of the solution, sorb substantial amount of PQ (q
max = 0.13 mmol g−1). |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|