**4. Conclusion**

In this research, modern and conventional technologies for remediation of soils and waste waters contaminated with heavy and toxic elements were briefly presented. Among these approaches, we can consider physical, chemical, bioremediation and combined methods. Effective factors, advantages, disadvantages and cost comparison in these methods were mentioned. Today, the methods of purifying water and soil pollution have grown almost adequately and progress has been made in this field, but it does not meet the real needs of the environment. With the continuous progress of science and the emergence of new technologies, newer methods are proposed.

At the same time, all the proposed methods have limitations. For example, in the treatment of contaminated soils through replacement, the method of storage and subsequent leaching of heavy toxic elements from the transferred soil is problematic and is still a matter of controversy among scientists. Also, phytoremediation is a long and time-consuming process. In comparison to green methods such as phytoremediation, chemical remediation methods have better advantages, including faster applicationresponse and larger scales.

However, pollution purification methods, especially chemical methods, need a long way to reach full maturity. Among these cases, reducing secondary pollution due to leaching of heavy elements and identifying newer economic chemicals for chemical oxidation-reduction and optimal immobilization of pollution. To achieve the mentioned goal, it is necessary to turn to group and interdisciplinary researches. Group and interdisciplinary researches can lead to the formation of new technologies that overcome the weaknesses of existing methods. For example, extensive research should be done to make selective separation of pollution from water environments.

*New Advancements in the Field of Pollution Treatment, Including Contamination of the Soil… DOI: http://dx.doi.org/10.5772/intechopen.109955*
