Water purity is becoming a matter of concern. Contamination with different organics and microorganisms is becoming a real challenge. Ozonolysis, oxidation with H2O2 or chlorination are cpmmonlu used, but could be relatively costly and unfriendly to the environment. Photo-electrochemical (PEC) processes are emerging. Such processes depend on the free solar energy radiations to drive degradation of water contaminants. Typically speaking, nano-size particles of TiO2 or ZnO, with band gap values ~3.2 eV, are being used. The materials are safe, relatively stable and non-hazardous. However, their wide band gap values demand UV radiations for electron-hole separation. UV radiations make only up to 5% of the reaching solar radiations. To activate such materials under visible light, dye molecules are being used as sensitizers, Scheme I. Different synthetic dyes are being examined, but all are potentially hazardous . Natural dye sensitizers are excellent alternative . This work describes how natural dye sensitized nano-ZnO particles have been efectively used to degrade chlorophenol molecules in water. Degradation of gram negative bacteria in water has also been assessed. Organic contaminants underwent complete mineralization with no organic matter left in solution. Microrganisms have been killed by the process. More importantly, all organic molecues that leached out of the killed bacteria have been also mineralized leaving no organic content in water. Details of results, discussions and models will be presented [3-4]. Keywords: PEC ; Nano-ZnO; Photo-degradation; Chlorophenols; Bacteria References  H. S. Hilal, A. H. Zyoud, Nidal Zaatar and Cheknane Ali, Guy Campet, DaeHoon Park, Iyad Saadeddin " CdS-sensitized TiO2 in phenazopyridine photo-degradation: Catalyst efficiency, stability and feasibility assessment ", Journal of Hazardous Materials, 173 (2010) 318-325  A. Zyoud, N. Zaatar, I. Saadeddin, M. H. Helal, G. Campet, M. Hakim, D.H. Park and H. S. Hilal, “Alternative natural dyes in water purification: Anthocyanin as TiO2-sensitizer in methyl orange photo-degradation”, Solid State Sciences 13 (2011) 1268-1275. (Elsevier; Journal Impact Factor 1.9, 2012)El Rhazi, M., Majid, S. (2014), Trends in Environmental Analytical Chemistry.,2, 33-42.  S.s Ateeq, MSc Thesis, An-Najah N. University, Palestine, (2013).  J. Shteiwi, MSc Thesis, An-Najah N. University, Palestine, (2014).