title: Treatment challenge of a cyanobacterium Romeria elegans bloom in a South Australian wastewater treatment plant - a case study.
abstract: A bloom of the non-toxic cyanobacterium Romeria elegans in waste stabilisation ponds (WSPs) within Angaston waste water treatment plant (WWTP) has posed an unprecedented treatment challenge for the local water utility. The water from the WSPs is chlorinated for safety prior to reuse on nearby farmland. Cyanobacteria concentrations of approximately 1.2 × 106 cells mL-1increased the chlorine demand dramatically. Operators continuously increased the disinfectant dose up to 50 mg L-1to achieve operational guideline values for combined chlorine (0.5-1.0 mg L-1) prior to reuse. Despite this, attempts to achieve targeted combined chlorine residual (CCR) failed. In this study, samples from the waste stabilisation pond at Angaston WWTP were chlorinated over a range of doses. Combined chlorine, disinfection by-product formation, cyanobacteria cell concentration, Escherichia coli inactivation, as well as dissolved organic carbon and free ammonia were monitored. This study shows that, in the occurrence of cyanobacterial blooms, CCR does not directly suggest pathogen removal efficiency and is therefore not an ideal parameter to evaluate the effectiveness of disinfection process in WWTP. Instead, E. coli removal is a more direct and practical parameter for the determination of the efficiency of the disinfection process.
authors.affiliation: a SA Water Corporation , Adelaide , Australia.
authors.forename: Radisti A
authors.initials: RA
authors.lastname: Praptiwi
authors.affiliation: a SA Water Corporation , Adelaide , Australia.
authors.forename: Carlos J
authors.initials: CJ
authors.lastname: Pestana
authors.affiliation: a SA Water Corporation , Adelaide , Australia.
authors.forename: Emma T
authors.initials: ET
authors.lastname: Sawade
authors.affiliation: a SA Water Corporation , Adelaide , Australia.
authors.forename: Nick
authors.initials: N
authors.lastname: Swain
authors.affiliation: a SA Water Corporation , Adelaide , Australia.
authors.forename: Gretchen
authors.initials: G
authors.lastname: Schroeder
authors.affiliation: a SA Water Corporation , Adelaide , Australia.
authors.forename: Gayle
authors.initials: G
authors.lastname: Newcombe
mesh_terms: D002713:Chlorine / Q000494:pharmacology*; D000458:Cyanobacteria / Q000187:drug effects* / Q000502:physiology; D004202:Disinfectants / Q000494:pharmacology*; D004203:Disinfection; D005068:Eutrophication / Q000187:drug effects*; D013021:South Australia; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000382:microbiology*
chemical_list: D002713:Chlorine; D004202:Disinfectants; D062065:Wastewater
keywords: Chlorination; Romeria elegans; cyanobacteria; wastewater; water reuse