Tertiary Phosphorus Removal Pilot Tests Technology Limits In Coeur D'Alene, ID

Abstract

Spokane River dischargers face restrictive phosphorus discharge limits that are technically challenging. A tertiary phosphorus removal pilot at the wastewater treatment plant was conducted between June and October 2006. Technologies from four different manufacturers were tested on their ability to reliably produce effluent total phosphorus (TP) concentrations of less than 50 µg/L and less then 10 µg/L. The demonstration pilot showed that effluent total phosphorus concentration of less than 50 µg/L can be produced by at least two of the tested technologies, Blue Water Technologies Blue Pro (DSBP) and Siemens Trident ® HS-1 (THS-1). While not fully demonstrated, GE (Zenon) ultrafiltration (ZW-500) and Parkson Incorporation Dual Sand (DSD2) would also likely be able to meet 50 µg/L. None of them showed ability to meet a 10 µg/L TP limit. While there were a number of days with 10 µg/L or less, they were few and far between.

Nutrient Management: Regulatory Approaches to Protect Water Quality: Volume 1 – Review of Existing Practices

“…A similar but shorter pilot study of three tertiary pilot units in Marlborough, MA, for a domestic wastewater with nearly 50% commercial and industrial components revealed intermittent recalcitrant phosphorus concentrations up to 500 µg/L (Lancaster and Madden, 2008). It is suspected that recalcitrant phosphorus is mostly, if not entirely, comprised of dissolved organic phosphorus (Neethling, et al, 2007). Some industrial effluents can contain 1,000-2,000 µg/L DNRP.…”

“…The nonreactive phosphorus is believed to be primarily organic in nature, but could contain other complexed phosphorus compounds. Similar to EDON, the following definitions are used for phosphorus species in the effluent (adapted from Neethling et al, 2007) -see also Figure 4-2:…”

“…The DNRP fraction is expected to follow trends similar to the DON and that 40-60% of the influent DNRP is possibly recalcitrant. Benisch et al (2007) reported residual EDNRP concentrations from advanced tertiary pilot studies in Coeur d'Alene, ID, and found a residual of 11 to 15 µg/L remain in the effluent. A similar but shorter pilot study of three tertiary pilot units in Marlborough, MA, for a domestic wastewater with nearly 50% commercial and industrial components revealed intermittent recalcitrant phosphorus concentrations up to 500 µg/L (Lancaster and Madden, 2008).…”

“…While inorganic and particulate phosphorus can theoretically be reduced to low concentrations (below 5 µg/L in some cases), removing EDNRP is very difficult. Results show the persistence of dissolved non-reactive phosphorus in all processes (data taken from Benisch et al, 2007). Table 4-8 shows the variability in performance for the phosphorus removal facilities in terms of the ratio between the best and average performance (3.84 th / 50 th percentile) and also the reliable performance (50 th /95 th percentile).…”

The coagulation–ultrafiltration process from pilot testing to full-scale design for the achievement of ultra-low phosphorus limit

“…Lower phosphorus concentration has been achieved at pilot scale. For example, some researchers have proven the ability to produce effluent TP less than 0.05 mg/L (Benisch et al 2007;Hugh & Tozer 2007). Hook & Ott (2001) selected six filter products to test TP removal using the Metro Wastewater Treatment Plant effluent as the experimental feed.…”