The objective of this study is to remove turbidity originating from algae present
in oxidation ponds effluents by an easy and inexpensive method. For this reason,
a novel lab-scale Step Feed Dual Treatment (SFDT) process was constructed and
the efficiency of trickling filter (TF) to remove algae and organic matter was
investigated. SFDT process developed in this study is the unique, inexpensive
and new system to scavenge algae from oxidation pond effluents. In this system,
influent is first treated in a stabilization pond, and subsequently they directed to a
TF, so as to provide a dual treatment. Moreover, some fraction of the raw
influent was directly sent to TF to maintain a steady biofilm on the TF medium.
Stabilization pond was not simulated in the experimental set-up as the main
objective of the study is to observe TF ability to scavenge algae from pond effluent. To determine the magnitude of the effect of individual operational
parameters (hydraulic loading rate, influent COD and chlorophyll-a
concentration) and of their combinations on organics and particle removal
efficacy an experimental design was followed. Experiments consistent with twolevel
factorial design with three variables (23) were performed. Hydraulic
loading rate (HLR) (0.5-2 m3/m2.day), influent COD (150-550 mg/l) and influent
chlorophyll-a concentrations (Chl-a) (250-600 µ / g/l) were selected as
independent variables. The COD and algae removal (as Chl-a) were selected as
dependent variables. Data obtained from the experiments showed that when HLR
(m3/m2.day) was increased from 0.5 to 2, Chl-a, NTU, SS and COD removals
were decreased, however, more than 85 % removal was attained in each case,
except for COD. The lowest removal efficiencies were obtained for all the
quality parameters when hydraulic loading was increased to 4 m3/m2.day. It was
observed that in general removal percentages for turbidity, Chl-a, SS and COD
increased considerably with the decreasing hydraulic loading rate. Highest
removals were obtained at lowest HLR. The removal of algae in TF was
presumably due to both flocculation (due to algal and bacterial EPS production)
and degradation (through bacterial activity) of algae. In conclusion, trickling
filter produced clear effluents, with less than 2 NTU, for most of the cases.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/2/12606578/index.pdf |
| Date | 01 September 2005 |
| Creators | Kaya, Devrim |
| Contributors | Dilek, Filiz B. |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for METU campus |
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