 Before my talk, I want to ask a question, is our water safe? Not really is probably an answer. Actually, we are staying in a planet with water and environment being heavily polluted. Pollutants are found in the surface water, groundwater, soil, sediments, and delta. Globally, at least 1.8 billion people are still using drink water source contaminated even with feces. Pollution from toxic chemicals are threatening life on this planet. For pollutants removal and treatment, it can be transferred back to 2000 years ago as represented by the buried pumping city in Italy. The urine at feces generated by people are collected in a public toilet and treated before discharging to the environment. Similar concept still applies to modern cities like the 7 star hotel in Dubai. Although treatment with water has greatly improved with technology development, we still have a long way to go. We need to move away from adjusting about removing simple organic compounds and starting about new technologies with less energy input, lower cost, and taking care of the emerging contaminants. They are readily distributed in the subsurface environment as shown in the coast region of the United States and many other populated cities. In addition, about one-third of industry's water and more than 90% of household sewage are discharged without being treated. One example of the personal organic pollutants is a flamer talent called PBDs. They are used widely in furniture and electronic products. Due to their high hydrophobicity, they are accumulated in the air, soil, sediments, freshwater, deep sea fish, marine mammals, polar bears, broad eggs, breast milk, or human tissue. The constitution of PBD in breast milk and wildlife has increased exponentially in the last 30 to 40 years. Some of them can turn the hormone balance of many species, having dramatic effects on the population structures. People have spent a great effort looking for microbes to detoxify them. Luckily, in my laboratory, a group of specialist bacteria are identified to detoxify these pollutants by altering their chemistry. Other ones, biological tools have been employed to understand the enzymes during the work. Also among these mechanisms, we found that CO2 has excellent capability to remove all the bromines from penta-tetral BDE as shown on the left-hand side to the final product, diphenyl ether, as shown on the right-hand side, within two weeks of time. Penta-tetral BDE are not only toxic, they can also change the hormone balance of people. One great challenge in biodegradation is the slow growth of mechanisms that fed with these toxic pollutants. We found that all specialist bacteria can grow on one pollutant to a high cell number, then apply them to another more toxic pollutants. In this way, the degradation time can be shortened from 120 days to 7 days. In terms of nutrients removal from wastewater, we developed a novel animal process. The key point of it is that bacteria can convert ammonia directly to nitrogen gas with all the requirements of oxygen at external organic carbon source. Therefore, it is the energy at cost saving process. The functional genes of all specialist bacteria are revealed by next generation sequencing technology. The second part of it is that microbial activity can be optimized as the functional genes can be used as a biomarker to track the bioremediation process in CQ. With all specialized bacteria and all monitoring tools available, we can grow all bacteria in large quantities, then apply them to the wastewater plant and also to the polluted sites. For them to carry out the bioremediation work. Overall, we are facing a great challenge in cleaning up our polluted water and environment. The good news is that a specialized group of bacteria has been identified to fight against certain persistent organic pollutants, always keeping in mind that soil reduction is still a critical step in protecting our water and environment. At the end, we need to think about what is the capacity of mechanisms in cleaning up our polluted water and environment? What are the advantages of biological process over physical chemical process? How to make the bioremediation process a sustainable process in terms of energy at cost saving? Thank you.