Water is a resource that is considered to be inexhaustible but after use, its quality shows changes. Dilution, self-purification and purification capacity are hampered by the complexity of pollutants and the increasing amounts of pollutants discharged. The world's population is constantly growing, and in direct proportion to this is environmental pollution and waste generation. The metallurgical industry, the mining extractive industry, the chemical and petrochemical industry, the textile industry, agriculture and the electricity production and distribution industry are the sources of water pollution with heavy metal pollutants. And after using water for household purposes, it generates impressive amounts of pollutants of this type. The treatment techniques currently used are becoming increasingly inadequate and outdated. Studies in the field of wastewater treatment, present the advantages of using biological treatment methods. The best known techniques studied are those of biosorption and bioaccumulation. These techniques use the ability of microorganisms adaptable to toxic environments to remove heavy metals from aqueous solutions. The parameters that influence these processes are the pH of the solution, the contact time, the temperature, the concentration of pollutants and the amount of biomass dosed. The paper will present the advantages and limitations of using these wastewater treatment techniques.

Acknowledgements: “The work of the first author is supported by the project ANTREPRENORDOC, in the framework of Human Resources Development Operational Programme 2014-2020, financed from the European Social Fund under the contract number 36355/23.05.2019 HRD OP /380/6/13 – SMIS Code: 123847. The work of the second author was carried out in the framework of the research project DREAM (Dynamics of the REsources and technological Advance in harvesting Marine renewable energy), supported by the Romanian Executive Agency for Higher Education, Research, Development and Innovation Funding – UEFISCDI, grant number PN-III-P4-ID- PCE-2020-0008.”