## 3 Results
### Adsorption Analyses  
Isothermal analyses of the sorption of organochlorine pesticides, including PCP, 2,4,6-TCP and lindane, onto APM surfaces are shown in Figure 5. The plots of APMs fit the [PERSON] model (r\({}^{2}>0.80\)) as indicated by good correlation coefficients and curved shapes indicating the presence of saturable sites. The plots of parent CM and SM showed a partitioning trend that fit the [PERSON] model indicating the lack of a saturable Q\({}_{\text{max}}\). Compared to parent clays, acid treatment resulted in a Q\({}_{\text{max}}\) in the range of 0.2 mol/kg for the chlorophenol toxins and approximately 0.5 mol/kg for lindane. Adsorption isotherms of APCMs and APSMs showed similarities in Q\({}_{\text{max}}\) and K\({}_{\text{d}}\) values for PCP and 2,4,6-TCP.  
Similarly, isothermal adsorption plots in Figure 6 showed sorption patterns for other pesticides including diazinon, linuron and trifuralin that fit the Langmuir model (r\({}^{2}>0.95\)). APCMs significantly increased the binding capacity of diazinon (-0.5 mol/kg), linuron (-0.2 mol/kg) and trifuralin (-0.1 mol/kg) compared to that of parent CM clay. Paraquat has two permanent positive charges on the quaternary nitrogens and these charges facilitate its attraction to the negatively charged clay interlayer surfaces of CM and SM (Q\({}_{\text{max}}\) = 0.29 and 0.44 mol/kg, respectively) as indicated by the Langmuir model (r\({}^{2}>0.94\)); due to less negatively charged interlayers in acid processed clays, the adsorption of paraquat by APCMs and APSMs was slightly reduced, as expected (Figure 7). The sorption parameters for each toxin on APMs and parent clays are summarized in Table 1.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Sorbents** & **PCP** & **2,4,6-TCP** & **Lindane** & **Diazinon** & **Linuron** & **Trifuralin** & **Paraquat** \\ \hline CM & K\({}_{\text{d}}=2.7\times 10^{4}\) & K\({}_{\text{d}}=4\times 10^{2}\) & K\({}_{\text{d}}=2.8\times 10^{2}\) & Q\({}_{\text{max}}=0.19\) & Q\({}_{\text{max}  
Figure 5: Langmuir adsorption isotherms for organochlorine pesticides: PCP, 2,4,6-TCP and lindane onto (**a**,**c**,**e**) APCM and (**b**,**d**) APSM surfaces, versus parent montmorillonite. Top: (**a**,**b**) showing isotherms for PCP. Middle: (**c**,**d**) showing isotherms for 2,4,6-TCP. Bottom: (**e**) showing isotherm for lindane.  
To investigate the safety and binding efficacy of APMs, a design mixture of pesticides (at an equal concentration of 2 ppm for each toxin) was prepared and its toxicity was confirmed in a living organism (Hydra vulgaris). This pesticide design mixture resulted in 100% mortality of hydra, following 92 h  
Figure 6: Langmuir adsorption isotherms for (**a**) diazinon (organophosphate), (**b**) linuron (urea-type) and (**c**) trifluralin (dinitroaniline) onto APCM surfaces.  
Figure 7: Langmuir adsorption isotherms for paraquat (bipyridyl) onto (**a**) APCM and (**b**) APSM surfaces.  
exposure. The inclusion of APCMs and APSMs at a rate of only 0.05% resulted in significant protection of hydra ranging from 60% to 67%. The inclusion of parent CM and SM clays, at the same inclusion rate, resulted in 0 and 10% protection, respectively. Importantly, APM inclusion at levels as high as 2% w/v in the hydra media showed no effect on hydra (Figure 8).