• Soil washing with pure water aided by the use of different chelating agents, solvents, and chemical additives can remove toxic metals; however, duration of the treatment process and low availability due to interaction with soil particles can be a major limitation.

• The sewage is carried to a central treatment works, where it undergoes a number of possible treatments that vary in their ability to break down or remove contaminants.

• Proper surface and subsurface drainage to remove excess water in a safe and timely manner plays an important role in controlling water related diseases.

• For example, some ideal candidates for the next generation of water treatment are those that are able to remove pathogens and chemical threats, actively transport molecules, move ions against concentration gradients, separate compounds in complex media or deactivate chemical agents.

• The ability of biosurfactants to remove crude oil entrapped within the soil matrix was 1.9–2.3 times grater than that of a synthetic surfactant.

• However, different surfactants were found to preferentially remove different components of the crude oil.

• Trash Skimmers such as The Trashcat have been developed to remove floating debris from busy harbours and other heavily polluted areas.

• Zinc oxide nanoparticles have been used to remove arsenic from water, even though bulk zinc oxide can not absorb arsenic.

• Synthetic adsorbents modified with surfactants have also been used to remove PPCPs from complex matrices.