Comparison of disinfection byproduct (DBP) formation from different UV technologies at bench scale

2002 ◽  
Vol 2 (5-6) ◽  
pp. 515-521 ◽  
Author(s):  
W. Liu ◽  
S.A. Andrews ◽  
J.R. Bolton ◽  
K.G. Linden ◽  
C. Sharpless ◽  
...  

The impact of UV irradiation on disinfection byproduct (DBP) formation was investigated for low pressure, medium pressure and pulsed UV technologies using a broad range of UV doses. Four classes of DBPs (THMs, HAAs, aldehydes and carboxylic acids) were examined. This enabled the determination of effects resulting from the direct action of UV irradiation on natural organic matter (aldehydes, carboxylic acids) as well as effects on the ultimate formation of chlorinated DBPs (THMs and HAAs) from secondary chlorination. For doses of less than 1,000 mJ/cm2, UV irradiation did not affect THM and HAA formation in subsequent chlorination processes, however higher UV doses resulted in lower ultimate concentrations of THMs and HAAs. UV irradiation also resulted in the formation of aldehydes and carboxylic acids at UV doses above 500 mJ/cm2, compounds that are known to adversely effect drinking water biostability.

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
G. O. Bosire ◽  
J. C. Ngila ◽  
H. Parshotam

The extraction and determination of aliphatic and aromatic carboxylic acids as well as their influence on the aromaticity and molecularity relationship of natural organic matter (NOM) in water are reported in this study. Three solid phase extraction (SPE) sorbents were used and their extraction efficiencies evaluated after chromatographic determinations (using gas chromatography with a time of flight mass spectrometer (GC × GC-TOFMS) and liquid chromatography with organic carbon detector (LC-OCD)). More than 42 carboxylic acids were identified in raw water from the Vaal River, which feeds the Lethabo Power Generation Station, South Africa, with cooling water. The aromatic carboxylic acid efficiency (28%) was achieved by using Strata™X SPE while the highest aliphatic carboxylic acid efficiency (92.08%) was achieved by silica SPE. The hydrophobic nature of NOM in water depends on the nature of organic compounds in water, whether aromatic or aliphatic. The LC-OCD was used to assess the hydrophobicity levels of NOM as a function of these carboxylic acids in cooling water. The LC-OCD results showed that the aromatic nature of NOM in SPE filtered water followed the order Silica>Strata X>C-18. From the results, the hydrophobicity degree of the samples depended on the type and number of carboxylic acids that were removed by the SPE cartridges.


RSC Advances ◽  
2017 ◽  
Vol 7 (55) ◽  
pp. 34339-34347 ◽  
Author(s):  
Xin Zhong ◽  
Chongwei Cui ◽  
Shuili Yu

The reaction between ozone and natural organic matter (NOM) generates a certain amount of aromatic carboxylic acids (ACAs).


2018 ◽  
Vol 79 (5) ◽  
pp. 929-937 ◽  
Author(s):  
Chanathip Hirun-Utok ◽  
Songkeart Phattarapattamawong

Abstract This research aimed to investigate the degradation of natural organic matter responsible for the formation of trihalomethane (THM), haloacetic acid (HAA) and haloacetonitrile (HAN) during ultraviolet (UV) photolysis and a co-exposure of UV with chlorine (UV/chlorine) and chloramine (UV/chloramine). Low pressure UV (LPUV) and vacuum UV (VUV) lamps were used for photolysis. VUV and LPUV irradiation changed aromatic/unsaturated structures to aliphatic ones, resulting in decreased THM and HAN formation. Following irradiation for 60 min, LPUV decreased THM and HAN by 16% ± 2% and 20% ± 6%, respectively. VUV decreased THM and HAN formation by 23% ± 3% and 20% ± 8%, respectively. HAA formation increased following photolysis. UV/chlorine treatment decreased THM, HAA and HAN. Higher chlorine doses had an inversely proportional relationship with THM and HAN formation. A chlorine dose of 4 mg·L−1 led to the greatest reductions, corresponding to 42% ± 2%, 10% ± 10% and 18% ± 6% for THM, HAA and HAN, respectively. UV/chloramine decreased the formation of THM more than UV/chlorine. With a chloramine dose of 4 mg·L−1, THM, HAA and HAN formation decreased by 74% ± 10%, 10% ± 10% and 11% ± 10%, respectively. This study showed the potential use of UV/chlor(am)ine for controlling the formation of THM, HAA and HAN.


2014 ◽  
Vol 56 (4) ◽  
pp. 912-920 ◽  
Author(s):  
Jasmina Agbaba ◽  
Aleksandra Tubić ◽  
Božo Dalmacija ◽  
Malcolm Watson ◽  
Jelena Molnar ◽  
...  

2007 ◽  
Vol 7 (18) ◽  
pp. 2651-2655 ◽  
Author(s):  
M.A. Zazouli ◽  
S. Nasseri . ◽  
A.H. Mahvi . ◽  
A.R. Mesdaghinia . ◽  
M. Younecian . ◽  
...  

2019 ◽  
Vol 78 ◽  
pp. 204-214 ◽  
Author(s):  
Nana Osei B. Ackerson ◽  
Alexis H. Killinger ◽  
Hannah K. Liberatore ◽  
Thomas A. Ternes ◽  
Michael J. Plewa ◽  
...  

2001 ◽  
Vol 1 (4) ◽  
pp. 25-33
Author(s):  
A. I. Schäfer ◽  
A.G. Fane ◽  
T.D. Waite

Nanofiltration (NF) can remove natural organic matter (NOM) and multivalent ions from surface waters. Large hydrophobic organics and calcium ions are responsible for irreversible fouling of nanofiltration membranes and thus a decrease of process efficiency and increase in cleaning requirements. Fouling due to the precipitation of organic-calcium complexes and the impact of colloids and coagulant (FeCl3) on the precipitation of these species was investigated. Coagulation in solution (as opposed to in the boundary layer) did not cause significant flux decline and was able to prevent irreversible fouling under conditions which were previously determined as detrimental. The rejection was varied if a strongly charged solid was deposited on the membrane.


2020 ◽  
Author(s):  
Ting Wang

<p>Natural organic matter (NOM) played an important role in the riverine and global carbon cycle. In order to evaluate the impact of river discharge and anthropogenic activities on the spatio-temporal variability of NOM content and sources in Lancang River, China, a comprehensive study was conducted in two years from the head to the leave-boundary section. As results, the DOC value ranged among 0.91-2.80 mg/L, with sharp decrease in the middle reaches and downstream. While the SOC value significantly enhanced along the water flow, varied from 0.06% to 3.54%. The isotopic composition of organic carbon (δ13C) suggested that predominant contribution of NOM is C3 plants in the upper reach, algae and soil organic matter in the middle reach, and aquatic plants in the downstream. EEM-PARAFAC results proved that NOM in Lancang River is mainly terrestrial organic carbon, while in situ microbial transformed NOM is very low. Moreover, the sharp increase of dissolved CO2 concentration in the lower reaches confirmed the strong respiration of microorganisms due to the higher DO and water temperature, thus resulted in the significantly different fluctuations of DOC and SOC.</p>


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