scholarly journals N-Nitrosodimethylamine Formation from Treatment of Seasonally and Spatially Varying Source Water

Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2019
Author(s):  
Maxwell C. Meadows ◽  
Soni M. Pradhanang ◽  
Takahiro Fujioka ◽  
Hitoshi Kodamatani ◽  
Menu B. Leddy ◽  
...  
Keyword(s):  
Water Treatment ◽  
Treatment Plant ◽  
Treatment Strategies ◽  
Water Treatment Plant ◽  
Current Treatment ◽  
Additional Treatment ◽  
Water Type ◽  
Source Water ◽  
Treatment Techniques ◽  
Spatially Varying

N-nitrosodimethylamine (NDMA) is a disinfection by-product (DBP) that has been classified as a probable human carcinogen in multiple risk assessments. NDMA presence in drinking water is widespread and dependent on source water, disinfectant type, precursors, and water treatment strategies. The objectives of this study were to investigate NDMA formation potential in a modeled monochloramine water treatment plant (WTP) fed by seasonally and spatially varying source water; and to optimize DBP precursor removal by combining conventional and additional treatment techniques. After NDMA analysis, it was found that NDMA formation was significantly dependent on source water type and monochloramine contact time (CT); e.g., at 24 h CT, Cork Brook produced 12.2 ng/L NDMA and Bailey Brook produced 4.2 ng/L NDMA, compared with 72 h CT, Cork Brook produced 4.1 ng/L NDMA and Bailey Brook produced 3.4 ng/L NDMA. No correlations were found between traditional DBP precursors such as total organic carbon and total nitrogen, and the formation of NDMA. The laboratory bench-top treatment system was highly effective at removing traditional DBP precursors, highlighting the need for WTPs to alter their current treatment methods to best accommodate the complex system of DBP control.

Specific Fluorescent Fingerprint of Organic Matter in Advanced Water Treatment and its Molecular Weight

2013 ◽  
Vol 448-453 ◽  
pp. 317-321 ◽  
Author(s):  
Jing Wen Cao ◽  
Shao Wei Liao ◽  
Chung Yi Chung ◽  
Hwa Sheng Gau ◽  
Chun Yen Chiu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Organic Matter ◽  
Water Treatment ◽  
High Performance ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Excitation Wavelength ◽  
Source Water ◽  
Fluorescent Intensity ◽  
Treated Water

In this research, the UV absorbance values of wavelength at 210 and 254 nm, excitation emission fluorescent matrix were measured for source water and treated water in CCL (Cheng Ching Lake) water treatment plant during five months. The whole data produced from EEFM was analyzed by PARAFAC operated in MATLAB software. The variation of molecular weight for organic matter was measured by HPLC (high performance liquid chromatography) with UV and fluorescent detectors. Observed from the variation of UV210/UV254, high value in treated water compared with source water was found. More molecular weight less than 5 k Da was formed in the treated water with relative to source water. Also, both major components in source water were located at wavelengths of excitation/emission of 250/410 nm and 230/330 nm and those in treated water were 240/410 nm and 220/290 nm. Also, the fluorescent intensity, long excitation wavelength was higher than short excitation wavelength in source water. This phenomena was opposite with treated water.

Biosorption of Mn(II) by Immobilizing Dominant Bacteria on the Surface of Chitosan Cross-Linked GAC Beads

2013 ◽  
Vol 361-363 ◽  
pp. 793-796
Author(s):  
Yu Nan Gao ◽  
Rong Xin Zhang ◽  
Xiang Yu Tang ◽  
Xin Fu ◽  
Peng Cong
Keyword(s):  
Water Treatment ◽  
Dose Rate ◽  
Contact Time ◽  
Removal Rate ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Source Water ◽  
Static Test ◽  
Dominant Bacteria

A static test was applied to study the biosorption of Mn (II) by immobilized dominant bacteria on the surface of chitosan cross-linked GAC(CCG) beads. The Citrobacter sp. was selected from the source water of the Shenyang first water treatment plant. Citrobacter sp. was immobilized on the surface of chitosan cross-linked GAC beads successfully. Langmuir models were applied to describe the isotherms. The Mn (II) removal rate was evaluated by the different dose rate and different contact time of the CCG beads. Results showed the dominant bacteria immobilized on chitosan cross-linked GAC beads were favourable adsorbers.

scholarly journals Nitrosamines: A review of formation pathways, precursors, control, and occurrence in drinking water

2019 ◽  
Vol 280 ◽  
pp. 05003
Author(s):  
Maxwell Meadows ◽  
Soni M. Pradhanang ◽  
Thomas B. Boving ◽  
Hichem Hadjeres
Keyword(s):  
Drinking Water ◽  
Water Treatment ◽  
Distribution System ◽  
Organic Nitrogen ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Source Water ◽  
Formation Potential ◽  
Nitrogen Containing Compounds ◽  
By Products

Nitrogenous disinfection by-products (N-DBPs) are emerging by-products that may be present in drinking water as by-products of water treatment plant (WTP) operations. Nitrosamines are N-DBPs that form by reaction of chloramine with certain organic nitrogen-containing compounds; however, the exact processes and environments in which nitrosamines form are still not well understood. Organic nitrogen precursors react within the WTP and distribution system, forming the toxic by-products during chloramination, or while in distribution. To best control the formation potential of nitrosamines, precursors must be removed from source water prior to chloramine disinfection. These nitrosamine forming precursors are abundant in source waters worldwide, presenting a need for further study of the mechanisms that reduce the formation potential of nitrosamines in chloramination WTPs.

Ceramic membranes for water treatment

2010 ◽  
Vol 10 (6) ◽  
pp. 987-994 ◽  
Author(s):  
Uwe Mueller ◽  
Gerhard Biwer ◽  
Guenther Baldauf
Keyword(s):  
Water Treatment ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Ceramic Membranes ◽  
Membrane Resistance ◽  
Pilot Scale ◽  
Feed Water ◽  
Water Type ◽  
Total Membrane ◽  
Filter Backwash Water

Ceramic membranes, different in pore size and membrane material, were applied to remove particulate and dissolved matter from different spent filter backwash water types as well as from dam water. The study was conducted in pilot scale under conditions typical for waterworks at a dam water treatment plant. A comparison of different ceramic membranes implied that total membrane resistance was more influenced by feed water type and by operation than by membrane type for the waters tested. Nevertheless, ceramic membranes seem to accumulate during operation less organic foulants especially polysaccharides compared to organic membranes leading to lower total membrane resistances for ceramic membranes during filtration process. Ceramic membranes may be considered to be applicable to treat spent filter backwash water as well as source water in public water supply.

scholarly journals Comparing Ozonation and Biofiltration Treatment of Source Water with High Cyanobacteria-Derived Organic Matter: The Case of a Water Treatment Plant Followed by a Small-Scale Water Distribution System

2018 ◽  
Vol 15 (12) ◽  
pp. 2633 ◽  
Author(s):  
I-Chieh Chien ◽  
Sheng-Pei Wu ◽  
Hsien-Chun Ke ◽  
Shang-Lien Lo ◽  
Hsin-hsin Tung
Keyword(s):  
Organic Matter ◽  
Water Treatment ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Cyanobacterial Blooms ◽  
Small Scale ◽  
Source Water

High cyanobacteria-derived dissolved organic carbon (DOC) in source water can cause drinking water quality to deteriorate, producing bad taste, odor, toxins, and possibly elevated levels of disinfection byproduct (DBP) precursors. Conventional water treatment processes do not effectively remove algal organic substances. In this study, rapid-sand-filtration effluent from a water treatment plant on Kinmen Island, where serious cyanobacterial blooms occurred, was used to evaluate the DOC- and DBP-removal efficiency of ozonation and/or biofiltration. To simulate a small-scale water distribution system following water treatment, 24 h simulated distribution system (SDS) tests were conducted. The following DBPs were analyzed: trihalomethanes (THMs), haloacetic acids (HAAs), haloacetonitriles (HANs), and trichloronitromethane (TCNM). Applying biological activated-carbon filtration (BAC) on its own achieved the greatest reduction in SDS-DBPs. Ozonation alone caused adverse effects by promoting THM, HAA, and TCNM formation. Ozonation and BAC filtration yielded better DOC removal (51%) than BAC filtration alone (41%). Considering the cost of ozonation, we suggest that when treating high cyanobacterial organic matter in water destined for a small-scale water distribution system, BAC biofiltration alone could be an efficient, economical option for reducing DBP precursors. If DOC removal needs to be improved, preceding ozonation could be incorporated.

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