Study On Organic Contaminants In Water And Photocatalytic Degradation

Water is one of the most precious nature sources. However, from 1950,rapid population growth, dramatic industrialization, unprecedentedurbanization and excessive use of water usage for agricultural production havefurther aggravated water shortage and contamination. Much attention has beenpaid to environmental protection and remediation for better living condition ofhuman beings. Wastewater treatment has become a main consideration inmany counties. Many metallopoiphyrins acting as a structural center ofchlorophyll, hemoglobin, vitamin B12 and some bioenzymes, play animportant role in life science. Moreover, they have been found to mimicphotochemical reactions in green plants for cleaning up the organiccontaminants. These processes could be finished with solar light under mildconditions. Solar light, water and metalloporphyrins constitute a mimic naturalsystem, and it is possible to reach the harmony of human and nature during theprocess of treating water pollution.On the basis of above facts and ideas, a series of research work have beencarried out, concerning the investigation of organic contaminants in drinkingwater and the treatment of wastewater. All of these researches and the relevantresults are reported in the following four parts.Part I Review on water quality, analysis and treatmentSevere scarcity of water and water pollution in North China, especially inGansu province are described here in detail. In order to resolve the localshortage of water for drinking and irrigation, "121" rainwater harvestingproject has been carried out efficiently and successfully. Following this,organic contaminants and their effects on health of human beings have beendescribed. With the improvement of analytical techniques, it is easy todetermine the water quality in rainwater harvesting systems.~ Various analyticalimethods are reviewed and compared. Meanwhile, the latest application anddevelopment of heterogeneous photocatalytic degradation have beendiscussed.Part IIDetermination of Organic Compounds in RainwaterHarvesting System by Gas Chromatography/MassSpectrornetry (GC/MS)In this study, the content of organic compounds and the degree ofcontamination of underground cistern water were investigated by GC/MS. Thewater samples were taken from different configurations of cisterns and sites inDingxi and Yuzhong Counties. Organic compounds were concentrated byliquid/liquid extraction from water samples. The quality and quantity analysesof organic compounds are identified by GCIMS. Eight series of compoundsare determined from all water samples. There are also contaminants containingbenzene cycle or heteroatom which have potential hazard on human health.Quality of water Sample DA3 is better than those of DA1 and DA2. Sourcesof contaminants are considered such as air, collecting surface, pipe system andcistern. Some improvements for cistern water quality are suggested.Part IIIPerformance of polymeric metalioporphyrins forphotocatalysisIn the presence of polymeric M [meso-tetra (4,4'-biphenybisulfony)phenylporphyrinj (PMTBPBSOPP M = Co, Mn, Cu, Zn, Fe), thephotocatalytic oxidative degradation of acridine orange (AO) was investigatedunder conditions of irradiatiorL with high-pressure mercury lamp (HPML),iodine tungsten lamp (ITL) and natural sunlight (NSL) respectively. Theexperimental results confirmed that polymeric metalloporphyrins could fUllydecompose AO under natural sunlight within three hours which is more rapidthan using artificial light sources such as HPML and ITL. The degradation ofAO obeys the first order kinetics. Meanwhile, a number of factors affectingiiphotocatalytic degradation effects, such as the initial concentration of AO,light sources and pH etc., were studied in detail. The experiments also...