**3.1 Physical and chemical technologies**

Conventional wastewater treatment methods are currently beset by several issues, including increased chemical usage, sludge disposal, and increased energy and space needs. Furthermore, effective elimination of recalcitrant organic components, the inability to handle more wastewater than the limited design capacity, and a scarcity of experienced labour are all major operational issues in these systems. Because of all of these operational and technological limitations in traditional wastewater treatment methods, researchers are working to establish novel categories of advanced wastewater treatment techniques to address the aforementioned issues. Advanced wastewater techniques must integrate membrane technology, Advanced Oxidation Processes, Less sludge formation and if sludge is formed, how to use the sludge rather than disposing of it at the dumpsite, adsorption materials with a low cost, fewer chemical or bioflocculant usage, a new group of nanoparticles for wastewater treatment. Although there is a large body of study on the aforementioned topics, there are still areas that need improvement in the open literature to tackle the concerns of developments in wastewater treatment methods. The employment of modern wastewater technologies in conjunction with traditional methods may lead to more efficient wastewater treatment as well as increased reuse and recycling of treated water.

## *3.1.1 Membrane technologies*

Membrane technology has several drawbacks, including greater energy consumption and fouling. Developing novel membrane materials, calculating hydrodynamics, incorporating modules, and exploring innovative modes of operation to reduce energy usage or application parameters to improve the treatment of water or wastewater are all examples of current advancements linked to membrane technology. All membrane processes have

*Available Technologies for Wastewater Treatment DOI: http://dx.doi.org/10.5772/intechopen.103661*

a minimal impact on the environment. There are no hazardous chemicals that must be disposed of, and no heat is generated in the operations. Future trends will include the recovery of valuable compounds, utilization of process waters, technological development including forwarding osmosis and pervaporation, real-time fouling monitoring, the advancement of existing fouling analysis techniques, the creation of custom-made novel membranes, and the development of membranes that can be applied in extreme circumstances. As these objectives are met, capacity, selectivity, and cost, as well as environmental effects including chemical consumption and concentrate handling should be addressed.

Membrane processes play an important role as well. As materials and membrane processes advance, new applications such as new MBRs (membrane bioreactor technologies), advanced osmosis, and pervaporation systems will be accessible. Anaerobic MBRs decompose organic compounds using anaerobic bacteria. In this configuration, biogas can replace the air in the submerged reactor. Due to their lower energy use, MBR systems outperform conventional systems. Since anaerobic MBR systems can retain high biomass concentrations, withstand high organic loadings, recover organic and energy acid, and generate little sludge, they are promising. Another promising technique is microbial fuel cells, a new form of MBR. Decentralized treatment systems can be utilized in wastewater systems to reduce costs and promote sanitation and reuse [57, 58].

### **3.2 Biological technologies**

The biological treatment process is a well-known technique for dealing with problems associated with the treatment of industrial effluents and municipal wastewaters, where conventional technologies have proven to be prohibitively expensive, time-consuming, and ineffective. Though the aerobic technique has been successful in terms of industrial application, there are some drawbacks, such as greater capital costs for aeration facilities, increased operational costs (especially for energy for pumps or aerators), increased maintenance demands, and probably surveillance requirements for detecting the dissolved oxygen content in the liquid. While for the anaerobic treatment post-treatment of wastes generated because treated water does not meet standards, odor generation, fouling/clogging of the membrane, and a slower start-up time are some of the limitations. Bioremediation is only possible with biodegradable chemicals. Not all substances can be completely degraded in a short period. There are concerns that the biodegradation byproducts will be more persistent or dangerous than the main contaminant. Extrapolating some biological technologies from bench and pilot-scale to large scale operations is still challenging. Biological mechanisms are frequently very specialized. The availability of metabolically competent microbial communities, proper environmental growth parameters, and optimum quantities of nutrients and pollutants are all crucial site considerations.

Biological treatment technology is an innovative tool with significant future potential. As scientists understand more about its functionalities, it is possible to become one of the most effective methods for wastewater and environmental remediation. The tremendous improvement of molecular biological technologies has made it possible to analyze the organization of microbial communities without being influenced by cultivation. To achieve effective system operation with diverse functional microorganisms, careful management and modification of environmental parameters are required for system performance. The invention of innovative techniques and new concepts (e.g., new functional components and novel biological metabolism

pathways) will facilitate the advancement of biological wastewater remediation systems. The best approach to achieving this goal is interdisciplinary collaboration.
