3.5. Artificially recharged ground waters
Infiltration through soil effectively removed organic
matter from water. TOC decreased here on average by
56%, AOCpotential by 40%, total phosphorus below
detection limit and MAP by 67% (Table 3). Also, the
counts of total bacteria and heterotrophic bacteria
decreased (Table 3), as found earlier [27]. Treated water
had heterotrophic bacterial counts of 34 CFU/ml on
average. Surprisingly, microbial growth potential with
or without nutrient addition increased infiltration on
soil, probably as a result of changes in microbial
community [28]. Also, the grazing of protozoa in
untreated lake or river water can have an impact on
the community structure and physiological status of
bacteria [29].
Bank filtration applied in one waterworks (A3)
removed effectively organic matter and bacteria, but
highly increased the content of phosphorus in water.
All waterworks have different water purification
processes, because of different quality of raw water.
For this reason, the number of some separate purification
processes in this study was low and thus limited the
statistical significance of the results in Tables 2 and 3.
Summary of the effects of different treatment processes
for organic carbon, phosphorus and microbial numbers
is shown in Tables 4 and 5.
3.6. Drinking water quality in various waterworks
All surfacewater works applied chemical coagulation,
which effectively removed of organic matter and