scholarly journals Use of photocatalysis for conversion of harvested rainwater as an alternative source into drinking water

2018 ◽  
Vol 20 (2) ◽  
pp. 243-256

The aim of this study is to investigate the performance of solar photo-catalyst of titanium oxide (TiO2/Solar) process to treat rainwater. The polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) in rainwater were chosen to be investigated in this study. The rainwater characterization results revealed that PAHs (NAP, FLT, and PYR) were more predominant in industrial and urban residential areas, whereas OCPs (LIN and DDT) were found to contaminate more on the agricultural and rural residential areas. Central composite design with response surface methodology was used to evaluate the relationships between operating variables for TiO2 dosage, pH, and and initial concentration to identify the optimum operating conditions. Quadratic models for FLT, PYR, LIN, and DDT prove to be significant with low probabilities (<0.0001). The obtained optimum conditions included pH (7), TiO2 concentration (1.54 g/L), and initial concentration (125 µg/L). The maximum removal rates were for FLT (88%), PYR (90%), LIN (66%), and DDT (79%). The polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) removal rates correspond well with the predicted models. The photo-degradation process of FLT, PYR, LIN, and DDT followed pseudo first order rate of reaction through L-H kinetic model. The proposed treatment process achieved higher degradation efficiencies for FLT, PYR, LIN, and DDT.

2020 ◽  
Vol 10 (9) ◽  
pp. 867
Author(s):  
Mikhail V. Milyukin ◽  
Maksym V. Gorban ◽  
Maksym V. Gorban

<div><p>This article presents the monitoring results of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs) in surface water of the Dnieper River for the period 2011–2019. Total levels of OCPs, PCBs and PAHs consist of 1,4–17,1; 2,8–57,2; and 7,5–378,6 ng/L, respectively. A significant increase in pollution levels was not identified. Research results of the disperse-phase distribution of these substances in water were also provided. Less than half of the total contents of pollutants were in the water phase. Average water-soluble parts of OCPs, PCBs, and PAHs accounted for 32, 42, and 44 %, respectively. It was shown that water-soluble parts of individual pollutants decrease with the increase in <span style="text-decoration: line-through;">the</span> coefficients of hydrophobicity of compounds. The clearest reliable, relevant correlation between water-soluble parts of individual congeners and coefficients of hydrophobicity was obtained for PCBs.</p></div><p align="center"><strong><br /></strong></p>


2019 ◽  
Vol 37 (4) ◽  
pp. 394-401 ◽  
Author(s):  
Weihua Gu ◽  
Jianfeng Bai ◽  
Wenyi Yuan ◽  
En Ma ◽  
Chenglong Zhang ◽  
...  

Polycyclic aromatic hydrocarbons (PAHs) are considered to be persistent organic pollutants, which pose a great threat to human health and the surrounding environment. In order to explore the influence of informal electronic waste (e-waste) dismantling activities on inhabitants who live nearby, soil samples were collected from informal e-waste dismantling areas in Xinqiao, China and analysed for 16 United States Environmental Protection Agency (USEPA) priority PAHs. Results indicated that the 16 USEPA priority PAHs were found at all seven sampling locations. Sampling location 3, which was only 10 m away from a residential area, had 1053.69 μg kg−1 of PAHs and seriously exceeded the standard value specified by the Netherlands. The total percents of 4-ring and 5-ring PAHs accounted for 61.74 and 71.70%, respectively, indicating that most of the detected PAHs belonged to high-ring PAHs. The informal e-waste dismantling activities are the major sources of soil PAHs in Xinqiao. Furthermore, the concentration of seven carcinogenic PAHs was 114.76 μg kg−1 and represented a potential health risk to humans. Thereinto, benzo[a]pyrene contributed the most, accounting for more than 50% in these locations. Our results may provide a reference about the influence of informal e-waste dismantling activities on the surrounding inhabitants and suggest that e-waste dismantling activities must be conducted in a formal enterprise which is far away from residential areas.


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