Photo-degradation of clofibric acid by ultraviolet light irradiation at 185 nm

2009 ◽  
Vol 60 (11) ◽  
pp. 2983-2989 ◽  
Author(s):  
Wenzhen Li ◽  
Shuguang Lu ◽  
Nuo Chen ◽  
Xiaogang Gu ◽  
Zhaofu Qiu ◽  
...  

As a metabolite of lipid regulators, clofibric acid (CA) was investigated in this study for its ultraviolet (UV) degradation at monochromatic wavelength of 185 nm using Milli-Q water and sewage treatment plant (STP) effluent. The effects of CA initial concentration, solution pH, humic acid (HA), nitrate and bicarbonate anions on CA degradation performances were evaluated. All CA degradation patterns well fitted the pseudo-first-order kinetic model. The results showed that ∙OH generated from water photolysis by UV185 irradiation was involved, resulting in indirect CA photolysis but contributed less to the whole CA removal when compared to the main direct photolysis process. Acid condition favored slightly to CA degradation and other constituents in solution, such as HA (5.0–100.0 mg L−1), nitrate and bicarbonate anions (1.0 × 10−3 mol L−1 and 0.1 mol L−1), had negative effects on CA degradation. When using real STP effluent CA degradation could reach 97.4% (without filtration) and 99.3% (with filtration) after 1 hr irradiation, showing its potential mean in pharmaceuticals removal in UV disinfection unit. Mineralization tests showed that rapid chloride ion release happened, resulting in no chlorinated intermediates accumulation, and those non-chlorinated intermediate products could further be nearly completely degraded to CO2 and H2O after 6 hrs.

2011 ◽  
Vol 63 (10) ◽  
pp. 2123-2130 ◽  
Author(s):  
A. Rodríguez ◽  
R. Rosal ◽  
M. J. Gomez ◽  
E. García-Calvo ◽  
A. R. Fernandez-Alba

The system ozone and hydrogen peroxide was used to reclaim wastewater from the secondary clarifier from a Sewage Treatment Plant (STP) of Alcalá de Henares (Madrid-Spain). The assays were performed by bubbling a gas mixture of oxygen and ozone, with ∼24 g Nm−3 of ozone concentration, through a volume of wastewater samples for 20 minutes at 25°C . The removal of dissolved micropollutants such as Pharmaceutical and Personal Care Products (PPCPs) and Organic Carbon (TOC) was enhanced by adding periodic pulses of hydrogen peroxide while keeping pH above 8.0 throughout the runs. Removal efficiency ratios in the range of 7–26 mg O3/mg TOC and 0.24 mg O3 /ng micropollutants at 5 minutes of ozonation were assessed as reference data to reclaim wastewater from STP. The relation between the extent of TOC removed and ozone doses used was related by a second-order kinetic model in which the time-integrated ozone-hydrogen peroxide concentration was included.


2006 ◽  
Vol 1 (3) ◽  
Author(s):  
Dong-Jin Ju ◽  
Im-Gyu Byun ◽  
Chang-Han Lee ◽  
Gab-Hwan An ◽  
Tae-Joo Park

This study examined the removal of reactive dye onto dead cells in activated sludge collected from the municipal sewage treatment plant in Suyoung, Pusan. The biosorption of reactive dye from aqueous solutions using the activated sludge was studied using a batch system with respect to the initial pH, temperature, amount of adsorbent and the pre-treatment of the adsorbent. Both the Freundlich and Langmuir isotherm models could describe the adsorption equilibrium of the reactive dye onto the activated sludge with the Langmuir isotherm showing the best agreement. First- and second-order kinetic models were used to investigate the adsorption mechanism. The adsorption capacity of Rhodamine-B(Rh-B) onto the activated sludge increased with decreasing initial pH and temperature.


2018 ◽  
Vol 44 ◽  
pp. 00102 ◽  
Author(s):  
Magdalena Łój-Pilch ◽  
Anita Zakrzewska ◽  
Ewa Zielewicz

Municipal sewage treatment plants are specific technical objects that have a serious impact on the environment and humans. Analysis and management of risk allow early detecting and eliminating threats and reduce the negative effects of risk-generating events. Only a properly conducted identification enables the correct functioning of this process. There are many methods of risk identification, some of them are of universal use, others are focused on a given type of company or activity. In the case of municipal sewage treatment plants, one should use several methods at the same time due to the complexity of processes taking place in these objects. The purpose of this paper is to present methods used to identify risks of municipal sewage treatment plants.


2020 ◽  
Vol 15 (2) ◽  
pp. 142-151
Author(s):  
Peter Lukac ◽  
Lubos Jurik

Abstract:Phosphorus is a major substance that is needed especially for agricultural production or for the industry. At the same time it is an important component of wastewater. At present, the waste management priority is recycling and this requirement is also transferred to wastewater treatment plants. Substances in wastewater can be recovered and utilized. In Europe (in Germany and Austria already legally binding), access to phosphorus-containing sewage treatment is changing. This paper dealt with the issue of phosphorus on the sewage treatment plant in Nitra. There are several industrial areas in Nitra where record major producers in phosphorus production in sewage. The new wastewater treatment plant is built as a mechanicalbiological wastewater treatment plant with simultaneous nitrification and denitrification, sludge regeneration, an anaerobic zone for biological phosphorus removal at the beginning of the process and chemical phosphorus precipitation. The sludge management is anaerobic sludge stabilization with heating and mechanical dewatering of stabilized sludge and gas management. The aim of the work was to document the phosphorus balance in all parts of the wastewater treatment plant - from the inflow of raw water to the outflow of purified water and the production of excess sludge. Balancing quantities in the wastewater treatment plant treatment processes provide information where efficient phosphorus recovery could be possible. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. The mean daily value of P tot is approximately 122.3 kg/day of these two sources. There are also two outflows - drainage of cleaned water to the recipient - the river Nitra - 9.9 kg Ptot/day and Ptot content in sewage sludge - about 120.3 kg Ptot/day - total 130.2 kg Ptot/day.


2008 ◽  
Vol 37 (2) ◽  
Author(s):  
Maciej Walczak

Changes of microbial indices of water quality in the Vistula and Brda rivers as a result of sewage treatment plant operationThis paper reports the results of studies of microbiological changes in the water quality of the Vistula and Brda rivers after the opening of sewage treatment plants in Bydgoszcz. The study involved determining the microbiological parameters of water quality. Based on the results obtained, it was found that the quality of the water in both rivers had improved decidedly after the opening of the plants, although an increased number of individual groups of microorganisms was found at the treated sewage outlet from one of the plants.


2000 ◽  
Vol 36 (4) ◽  
pp. 161-171
Author(s):  
KENITSU KONNO ◽  
NAOKI ABE ◽  
YOSHIRO SATO ◽  
KOJI AKAMATSU ◽  
MAKOTO ABE ◽  
...  

2017 ◽  
Vol 1 (1) ◽  
pp. 46-55 ◽  
Author(s):  
Athar Hussain ◽  
Manjeeta Priyadarshi ◽  
Saif Said ◽  
Suraj Negi

Most of the industrial sewage effluents used for irrigation contains heavy metals which cause toxicity to crop plants as the soils are able to accumulate heavy metal for many years. The vegetables grown for the present study were irrigated with treated wastewater brought from a nearby full-scale sewage treatment plant at different compositions along with tap water as a control. The concentration levels of the Cd, Co, Cu, Mn and Zn in the soil were found to below the toxic limits as prescribed in literature. Daily Intake Metals (DIM) values suggest that the consumption of plants grown in treated wastewater and tap water is nearly free of risks, as the dietary intake limits of Cu, Fe, Zn and Mn. The Enrichment Factor for the treated wastewater irrigated soil was found in order Zn> Ni> Pb> Cr> Cu> Co> Mn> Cd. Thus, treated wastewater can be effectively used for irrigation. This will have twofold significant environmental advantages: (1) helpful to reduce the groundwater usage for irrigation and (2) helpful to reduce the stress on surface water resources.


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