**6. Conclusions**

All the extracts showed turbidity and color removal, with efficiencies higher than 88%, which indicates that the extraction methodologies conserve the coagulant and flocculant capacity of each plant.

The biopolymers of *Melocactus* sp., *Opuntia* sp., *Stenocereus griseus*, *Cereus forbesii*, *Aloe arborescens*, *Aloe vera*, and Kabuli chickpea (*Cicer arietinum* L.) have an activity for coagulation and water flocculation.

The plants with the best performance in the removal of turbidity and color were *Melocactus* sp., and Kabuli chickpea (*Cicer arietinum* L.), with the best percentages of elimination of solids of small size of water.

The Z potential measured to the extracts of *Melocactus* sp. and Kabuli chickpea (*Cicer arietinum* L.) has similar values in the range of pH 4–10, which shows a similar activity for the suspended particles of the water used in the tests.

The biopolymers of the plants *Melocactus* sp., *Opuntia* sp., *Stenocereus griseus*, *Cereus forbesii*, *Aloe arborescens*, *Aloe vera*, and Kabuli chickpea (*Cicer arietinum* L.) can be a viable alternative for the treatment of drinking and residual water, in replacement of sulfate of aluminum, aluminum polychloride, and ferric chloride; decreasing the amounts of dissolved metals in drinking water of humans and animals, especially with the aluminum residues associated with diseases such as autism and Alzheimer [16-23].
