Photooxidation Kinetics of Organic Pollutants in Municipal Waste Water

This study was designed to determine tlie occurrence and removal of Cryptosporidium spp. oocysts and Giardia spp. cysts, in municipal waste-water by waste stabilisation ponds in tlie Republic of Kenya. Eleven waste stabilisation pond systems located in towns across Kenya were included. A total of 66 waste-water samples were examined for the presence of oocysts and cysts, comprising 11 raw waste-water and 55 pond effluent samples over a two month period. Cryptosporidium spp. oocysts were detected in 6 and Giardia spp. cysts in 9 of the designated pond systems analysed demonstrating their ubiquitous nature throughout Kenya. Oocyst levels detected in raw waste-water samples ranged from 12.5 - 72.97 oocysts/l and various pond effluents between 2.25 - 50 oocysts/l. Cyst levels detected in raw waste-water samples ranged from 212.5 to 6212.5 cysts/l and in various pond effluents from 3.125 to 230.7 cysts/l. No Cryptosporidium spp. oocysts were detected in the final effluent from any pond systems studied (11/11). Whereas no Giardia spp. cysts were detected in the final effluent from 10 of 11 waste stabilisation pond systems studied, one pond system was found to be consistently discharging cysts in the final effluent at concentrations ranging from 40 to 50 cysts/l. The minimum retention period for the removal of Cryptosporidium spp. oocysts and Giardia spp. cysts was 37.3 days. Laboratory experiments were performed to assess physico-chemical and microbiological parameters to express relationships between pond performance and protozoa removal.

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Photocatalysis of Coomassie Brilliant Blue Using Clay Mineral

Materials Science Forum ◽

10.4028/www.scientific.net/msf.869.765 ◽

2016 ◽

Vol 869 ◽

pp. 765-767 ◽

Cited By ~ 3

Author(s):

Layane Rodrigues Almeida ◽

João Sammy Nery Souza ◽

Edson Cavalcanti Silva Filho ◽

Josy Anteveli Osajima

Keyword(s):

Organic Pollutants ◽

Uv Light ◽

Brilliant Blue ◽

Blue Dye ◽

Secondary Treatment ◽

Toxic Compounds ◽

Coomassie Brilliant Blue ◽

Kinetics Of ◽

Coomassie Brilliant ◽

Photocatalytic Processes

The presence of organic pollutants, which cannot be eliminated by conventional processes of primary and secondary treatment, can be problematic. Photocatalytic processes offer an efficient breakdown of organic pollutants into non-toxic compounds such as CO2 and H2O. This paper proposes the use of the titanium dioxide embedded in palygorskite as a photoactive material in the degradation of cationic dye, Coomassie Brilliant Blue. The system was irradiated using UV light for a maximum time of 120 minutes. The concentration of the dye used was 1.0x10-4 mol L-1 in 0.5 g L-1 of the photoactive material. The kinetics of the system was monitored by UV-Vis spectrophotometry. In 120 minutes of radiation, the process of photocatalysis reduced the initial concentration of the Coomassie Brilliant Blue dye in half.

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A New ACS Audio Course to help you understand and solve industrial and municipal waste-water problems ....

Environmental Science & Technology ◽

10.1021/es00102a701 ◽

1982 ◽

Vol 16 (8) ◽

pp. 425A-425A

Keyword(s):

Waste Water ◽

Municipal Waste ◽

Water Problems

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Simultaneous photochemical generation of ozone in the gas phase and photolysis of aqueous reaction systems using one VUV light source

Water Science & Technology ◽

10.2166/wst.1997.0081 ◽

1997 ◽

Vol 35 (4) ◽

pp. 41-48 ◽

Cited By ~ 11

Author(s):

T.M. Hashem ◽

M. Zirlewagen ◽

A. M. Braun

Keyword(s):

Gas Phase ◽

Light Source ◽

Organic Pollutants ◽

Vacuum Ultraviolet ◽

Oxidative Degradation ◽

Reaction System ◽

Photochemical Reactions ◽

Experimental Conditions ◽

Photochemical Generation ◽

Kinetics Of

A more efficient use of vacuum ultraviolet (VUV) radiation produced by an immersed Xe-excimer light source (172 nm) was investigated for the oxidative degradation of organic pollutants in aqueous systems. All emitted VUV radiation from one light source was used in two simultaneous but separate photochemical reactions: (1) photochemical generation of ozone by irradiating oxygen in the gas phase and (2) photolysis of the aqueous reaction system. The gas stream containing the generated ozone is sparged into the reaction system, thus enhancing the oxidative degradation of organic pollutants. The photochemically generated ozone in the gas phase was quantitatively analyzed, and the kinetics of the degradation of 4-chlorophenol (4-CP) and of the dissolved organic carbon (DOC) were determined under different experimental conditions. The results show that the rates of degradation of the substrate and of the DOC decrease in the order of the applied processes, VUV/O3 > O3 > VUV.

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