Adsorptive properties of the pesticides 2,4-D, mecoprop, and dicamba on a pinus-based biochar: Conventional and statistical physics evaluation

The adsorptive properties of the pesticides 2,4-D, mecoprop, and dicamba on a pinus-based biochar were scrutinized from conventional and statistical physics approaches. Firstly, the pinus-based biochar was prepared from Pinus elliottii and extensively characterized. Then, the conventional adsorption studies were made using kinetic equilibrium and thermodynamics. Subsequently, the statistical physics model of Hill was used to interpret the data. Finally, the pinus-biochar was used to uptake the pesticides from a real river water sample. The results revealed that the pinus-biochar is a rich-carbon material (carbon content higher than 99%) with high thermal stability, interesting textural features, and proper characteristics to effectively uptake small and polar organic molecules. At a pH of 7.0 and using 1.0 g/L, the biochar reduced the concentration of pesticide solutions from 50 & mu;g/L to less than 4.0 & mu;g/L in 2 h of operation. The conventional evaluation revealed that the General order model properly represented the kinetic profile of the pesticides adsorption, while the Langmuir model better represented the isotherms. The maximum uptakes of 2,4-D, mecoprop, and dicamba at 298 K were 100.9 & mu;g g-1, 122.5 & mu;g g-1, and 95.9 & mu;g g-1. The statistical physics model of Hill could explain the adsorption of all pesticides, and new insights were proposed for the adsorption mechanism. The pinus-based biochar was also efficient in decontaminating river waters containing the pesticides, using 5.0 g/L. Finally, it can be concluded that pinusbased biochar is a rich-carbon material able to efficiently uptake the pesticides 2,4-D, mecoprop, and dicamba from synthetic and natural waters. The efficiency, even in a concentration range of & mu;g/L, was attributed to the intrinsic features of the new material.

Automated summary

In this study, the adsorptive properties of pesticides on pinus-based biochar were examined using conventional and statistical physics approaches. The results showed that pinus-based biochar is a highly adsorbent material capable of efficiently removing pesticides from water sources.