| The feeding water of existing water treatment plant is extracted from LuanRiver. During the summer peak water demand season, the increased concentration ofalga species in the feeding water, which is resulted from the eutrophication in LuanRiver, leads to the negative impacts on the water treatment plant, including: worsenedcoagulation performance (more dosage of chemicals);decreased sedimentationperformance (flocs up-floating, increased frequency and water consumption rate ofsedimentation surface wash);degraded filtration performance (shortened filtrationcycle, enhanced backwash frequency and water consumption rate);undermineddisinfection performance (over consumption of disinfectant);and penetration of somealga through the filtration tank, which results in the degradation of product water. Asper the introduction above, therefore, the focal objective of this research is to optimizethe water treatment processes that are able to tackle the high contraction alga in thefeeding water during the summer peak water demand season.First of all, the identified problems occurred in the summer season of the lasttwo year shall be analyzed comprehensively in order to determine the primary causingfactors. Secondly, the most optimal pre-oxidation alga removal methodology andappropriate coagulant and flocculant are to be chosen through comparison andanalysis. Lastly, an optimized water treatment process shall be concluded aftercompletion of associated experiments and trials with respect to alga removal,coagulant and flocculant.It is concluded by the research that: it is viable to achieve the proposed treatmentobjectives to the alga concentrated feeding water during the peaking summer season,such as, lower turbidity, control of residual aluminum and pH, equivalent performanceof pre-chlorination, only if dosing chlorine dioxide as pre-oxidation algaecide,ploy-aluminum as coagulant, HCA as flocculant, without the needs of modification toexisting water treatment facilities. |
