FIELD-SCALE TESTING OF A HYPERFILTRATION UNIT FOR REMOVAL OF CREOSOTEAND PENTACHLOROPHENOL FROM GROUND-WATER - CHEMICAL AND BIOLOGICAL ASSESSMENT

Chemical analyses and biological response data were used to assess the efficacy of a field-scale hyperfiltration unit in the removal of poly cyclic aromatic hydrocarbons (PAHs) and other organic compounds from c reosote- and pentachlorophenol (PCP)-contaminated ground water. The hy perfiltration unit consisted of four modules containing porous stainle ss steel tubes which were coated with a formed-in-place zirconium hydr ous oxide-polyacrylic acid (ZOPA) membrane. A fivefold concentration o f the feed water (80% volume reduction) with up to 97% removal of high molecular weight PAHs was achieved during pre-demonstration and field -demonstration runs of the hyperfiltration unit. Approximately 68% of PCP was removed by the unit. Removal of phenolics averaged 27% and 36% , respectively, for the two runs. Toxicological/teratogenic data for e mbryonic inland silver-sides, Menidia beryllina, indicated that 100%, 10%, and 1% solutions of the ground water sample, used in the pre-demo nstration run, caused statistically significant (p less-than-or-equal- to 0.05) biological responses when compared to controls. Only the 1% s olution of permeate in the pre-demonstration run was nontoxic/teratoge nic. This 1% solution was also not very toxic in Microtox(R) tests. Th e 5-min EC50 was 56.44%. Acute toxicity tests with Ceriodaphnia dubia revealed a 48-h LC50 of > 1% permeate. Similar results were obtained i n the field-demonstration run of the hyperfiltration unit. In this run , feed water was toxic/teratogenic to Menidia beryllina embryos at 100 %, 10%, and 1% concentrations. Permeate from the field-demonstration r un was embryo toxic/teratogenic at 100% and 10% concentrations but not at 1%. The Microtox(R) 5-min EC50 was 58.50% at the 1% concentration and the Ceriodaphnia 48-h LC50 was 5.6% permeate in the field-demonstr ation run. The Escambia County Utilities Authority set a pre-discharge requirement of non-toxicity to Ceriodaphnia dubia for 1% permeate sol utions. Permeates from both runs, diluted to 1%, met the pre-condition of non-toxic responses in 48 h tests with Ceriodaphnia dubia. Meeting this requirement allowed for discharge of diluted permeate into the c ounty's sanitary sewerage collector system.