More about the role of 2,6-dichlorophenol in tick courtship: identification and olfactometer bioassay in Amblyomma cajennense and Rhipicephalus sanguineus

This study aimed to identify 2,6-dichlorophenol (2,6-DCP) in Amblyomma cajennense and to evaluate its role in A. cajennense and Rhipicephalus sanguineus courtship. Hexanic extract from attractive females was purified by solid phase extraction and the phenol was identified by the single ion monitoring method using GC/MS. In an olfactometer, the responses of A. cajennense and R. sanguineus males to females, control rubber septa or rubber septa impregnated with 2,6-DCP at 50, 500, and 5000 ng, respectively, were studied. 2,6-DCP was identified in A. cajennense extract and the males oriented themselves toward the concentration of 500 ng. These septa and the females were recognized as copula partners. The septa treated with 2,6-DCP did not attract and were not even recognized by the R. sanguineus males, whereas the females were recognized. Due to the presence of 2,6-DCP in A. cajennense and the results of biological bioassays, it was concluded that this compound acts as an attractant and mounting sex pheromone in this tick, but it does not play any role in R. sanguineus courtship.

Removal of phenol and chlorophenols from water by coir pith carbon: equilibrium and rate studies.

Batch mode studies were conducted to study the removal of phenol, 2,4,6-Trichlorophenol (TCP) and Pentachlorophenol (PCP) from aqueous solution on coir pith carbon by adsorption process under varying experimental conditions such as agitation time, adsorbent dose, pH and temperature. Kinetics of adsorption obeyed second order rate equation and the rate constant was found to be in the range 0.0098-0.0672, 0.0949-0.8801 and 0.172-0.305 g/mg/min for phenol, TCP and PCP respectively. Equilibrium adsorption data follow Langmuir isotherm for phenol and PCP and the adsorption capacities were found to be 48.3 mg and 3.7 mg/g, respectively. For TCP, adsorption followed Freundlich isotherm only. Acidic pH was favorable for the adsorption of all the chlorophenols. Studies on pH effect and desorption show that chemisorption seems to play a major rule in the adsorption process. The positive values of H0 24.99, 18.69, and 8.907 kJ/mol for phenol, TCP and PCP respectively, confirm the endothermic nature of adsorption.