AWWA ACE59982

The drinking water industry is faced with microbial contaminants that are challenging to remove or inactivate with conventional treatment technologies. Specialized and often costly technologies are required to treat particularly challenging target compounds such as protozoan pathogens (e.g., Cryptosporidium parvum) and viruses (e.g., adenovirus). Pulsed arc electrohydraulic discharge (PAED) is a direct plasma technology that has the potential to treat and/or inactive these microorganisms. Plasma technologies have the capability to treat water by several mechanisms including: shock waves, ultraviolet (UV) irradiation, radical reactions, electron processes, ionic reactions, and thermal dissociation (Chang et al., 2002). The advantage of utilizing direct plasma technologies such as PAED is that they are capable of simultaneously taking advantage of all of these mechanisms. Preliminary experiments using a laboratory-scale PAED were conducted to evaluate Escherichia coli and Bacillus subtilis inactivation with PAED. Preliminary data indicated that the mean log₁₀ inactivation of E. coli was 0, 2.6, 3.3, and 3.6 log at detention times of 0, 0.8, 1.5, and 5.8 minutes respectively. The frequency of electrohydraulic discharges was changed for a second trial yielding similar inactivation of E. coli of 0, 0.06, 1.4, and 2.82 log with corresponding detention times of 0, 0.3, 0.9, and 1.3 minutes, respectively. The mean B. subtilis inactivation after 0.9 and 1.3 minutes was 3.5 and 4.6 log, respectively. Pulsed arc electrohydraulic discharge offers an innovative approach that may offer concurrent treatment of microbial and chemical target compounds. The emergence of PAED technology as a viable treatment option will offer another effective barrier in a multi-barrier treatment system to ensure public health needs are met. Includes 8 references, figures.