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008    201202s2020    sw a|||||m||||000 0|eng|c 
020    9789174227642|qhäftad 
020    |z9789174227659 (pdf) 
041    eng 
082 04 363.61?|223/swe 
092 0  363|bengelska 
100 1  Pullerits, Kristjan,|d1991-|4aut 
245 10 Impact of drinking water treatment and pipe biofilms on 
       bacterial dynamics in the distribution system /|cKristjan 
       Pullerits 
264  1 Lund :|bDivision of Applied Microbiology, Department of 
       Chemistry, Lund University,|c2020 
264  3 Lund :|bMedia-Tryck,|c2020 
300    xviii, 97 sidor|billustrationer, tabeller|c24 cm 
336    text|btxt|2rdacontent 
337    unmediated|bn|2rdamedia 
338    volume|bnc|2rdacarrier 
500    Härtill 5 uppsatser 
502    Diss. (sammanfattning) Lund : Lunds universitet, 2020 
506 0  gratis 
520    This thesis addresses drinking water quality and 
       microbiology in full-scale drinking water distribution 
       systems (DWDSs). It examines how UV irradiation and slow 
       sand filters (SSFs) alter the water bacteriome, and how 
       the biofilm in the DWDS affects the drinking water 
       quality.In addition, the effects of installing a combined 
       ultra橬tration and coagulation treatment stage on the pipe
       biofilm com�鴹 in a DWDS were assessed.PCR-based methods 
       were assessed and developed to be able to monitor the 
       effects of UV irradiation. The impact of UV doses of 250, 
       400, and 600 J/m2, delivered to water at a full-scale 
       drinking water treatment plant (DWTP), was investigated 
       using 16S rRNA gene amplicon sequenc鮧. Phylogenetic 
       analysis, including differential abundance analysis using 
       DESeq2, showed that Actinobacteria were more resis䡮t to 
       UV irradiation, whereas Bacteroidetes were sensitive to UV
       irradiation. Amplicon sequence variants (ASVs) resistant 
       to UV had a greater average guanine-cytosine(GC) content 
       than ASVs sensitive to UV irradiation: 55% ± 1.7 (n = 19)
       vs. 49% ± 2.5 (n = 16), respectively. UV irradiation may 
       affect the microbial dynamics and the biostability 
       throughout the DWDS, as the composition of a bacterial 
       community in irradiated water stored for 6 days at 7 °C 
       to approximate conditions in the DWDS, changed compared to
       the non-irradiated controls.Full-scale SSFs were studied 
       using flow cytometry (FCM) and cytometric histogram image 
       comparison (CHIC) analysis. An established, well-
       functioning SSF removed coliforms and Escherichia coli, 
       and reduced the pH and the amount of total organic carbon,
       even when the schmutzdecke of the SSFs was removed. This 
       was in contrast to two new filters, which showed 
       compromised performance, including breakthrough of 
       coliforms and E. coli. FCM analysis showed that well-
       functioning SSFs changed the microbial community of the 
       influent water to include more low nucleic acid (LNA) 
       bacteria in the filter effluent. The SSF with a mixture of
       new sand plus sand from established SSFs on top exhibited 
       better performance than a SSF with new sand, indicating 
       that priming with sand from established SSFs may be 
       favorable when constructing new SSFs. Monitoring the SSFs 
       with FCM and CHIC analysis was demonstrated to be a fast, 
       reliable and informative method of monitoring the 
       bacterial community in water.An ultrafiltration and 
       coagulation step was installed at a DWTP (hereafter 
       defined as UF start). This removed almost all the bacteria
       from the finished water, and reduced the total cell 
       concentration (TCC) in the distributed water from 6.0 
       נ105軵00B1} 2.3 נ105) cells/mL to 6.0 נ103 (± 8.3 נ103) 
       cells/mL, taking seasonal variations into account. After 
       the UF start, almost all the bacteria in the drinking 
       water leaving the DWDS originated from the pipe biofilm, 
       although no significant biofilm detachment was observed. 
       The removal of cells by UF allowed the identification of 
       the bacteria released from the mature pipe biofilm, which 
       included Sphingomonas, Nitrospira,�cobacterium, and 
       Hyphomicrobium. The biofilms of excavated pipe sections 
       were analyzed over a period of 27 months in order to study
       how the biofilm adapted to the new UF water quality. It 
       was observed that the bacterial community was dominated by
       Nitrosomonadaceae, Nitrospira, Hyphomicrobiumᮤ 
       Sphingo�as, confirming the previous results. DNA 
       sequences classified as belonging to the opportunistic 
       pathogens Mycobacterium and쥧gionella were also detected 
       in the pipe biofilms. The high relative abundance of the 
       nitrifying bacteria Nitro㯭onadaceae and Nitrospira, 
       together with the fact that the turnover of nitrogen 
       compounds was unchanged by UF start indicated that 
       nitrification in the DWDS was localized to the pipe 
       biofilm. The bacterial community on the pipes changed 
       following UF start and a stable community was reached 
       after 18 months, while still maintaining the turnover of 
       nitrogen compounds. The bacteria leaving the biofilm after
       a shorter residence time (<25 h) were high nucleic acid 
       (HNA) bacteria, and a shift to an increased relative 
       abundance of LNA bacteria was observed with longer 
       residence times of up to about 170 h 
546    Populärvetenskaplig sammanfattning på svenska 
650  7 Mikrobiologi|2sao 
650  7 Vattenverk|2sao 
650  7 Patogena mikroorganismer|2sao 
650  7 Vattenrening|2sao 
650  7 Dricksvatten|xhälsoaspekter|2sao 
655  7 government publication|2marcgt 
710 2  Lunds universitet.|bTillämpad mikrobiologi|4pbl 
856 40 |uhttps://portal.research.lu.se/files/86070434/
       Kristjan_Pullerits_Thesis_Final.pdf 
856 40 |5APIS|uhttp://urn.kb.se/resolve?urn=urn:nbn:se:kb:dark-
       14514251 
856 42 |uhttps://www.lu.se/|zVärdpublikation