Recycle of Treated Effluent to Help Water Crisis

World is facing formidable challenges in meeting the rising demands of the clean water, as the available supplies of fresh water are depleting due to extended drought, population growth and completing demands of the users. With the rising demand of clean water and subsequent increase in waste water, it has become mandatory to treat waste water for achieving high-quality pure water for reuse to a large extent for cleaning, washing, flushing, gardening, etc. Ultrasound irradiation is a physical method in which waste water treatment is done using acoustic cavitation, which can affect a number of mechanical, chemical, biological and acoustic changes in waste water analysis. Ultrasound disintegration neither generates secondary toxic compounds nor contributes additional chemical compounds. In addition to physical sludge disintegration, many toxic and recalcitrant organic pollutants such as aromatic compounds, chlorinated and aliphatic compounds, surfactants, organic dyes, etc., are also broken down into simpler forms due to the generation of highly oxidative reactive radicals, i.e. hydroxyl (OH*), hydrogen (H*), hydroperoxyl (HO*2) and hydrogen peroxide (H2O2) during the ultrasound treatment resulting in the breakdown of these compounds. The present study shows that the effect of ultrasound, nanoparticles and UV treatment alone or in combination is very effective than the other treatment processes, for removal of organic, inorganic and biological pollutants and improving the aerobic and anaerobic digestibility. The sewage effluent samples tested experimentally before and after the treatment indicate improvement in the quality of effluent making it suitable for recycling it, for household and commercial usage.