Assessment of biologically active GAC and complementary technologies for gray water treatment

Abstract

The reuse of gray water for applications ranging from irrigation to showering is a viable means to reduce net water demand when water supplies are stressed. The objective of this study was to investigate the treatment of gray water using biologically active granular-activated carbon (GAC) and

Thermal swing intermittently-operated biological activated carbon filtration for rapid, non-sewered treatment of psychrophilic black water

“…Although the columns were not operated in duplicate in this study, IOBAC design and operation at 23 °C condition were similar to past IOBAC studies. Specifically, GAC columns had previously been operated for 6 months at the same temperature, at a similar design flux (e.g., 3.7-5.8 L min −1 m −2 ), and with the same seed population for the treatment of synthetic gray water 11 and municipal wastewater. 15 Those studies did not explore the efficacy of thermal swing, but provide a useful benchmark against which to compare 23 °C IOBAC performance in this study.…”

“…Each experiment was performed continuously for at least three weeks. Although each column study was limited to 30 days of operation due to funding constraints, it has been observed in past studies that the IOBAC system equilibrated within 3 weeks and maintained performance for up to 6 months, both when treating gray water influent at bench scale 11 and when treating municipal wastewater at pilot scale. 15 During the wastewater loading step, peristaltic pumps delivered ambient temperature influent at a hydraulic loading rate of 1.5 L min −1 m −2 to each column for 5 h (Fig.…”

“…However, 35% removal of solids (as measured by turbidity) was achieved in a previous IOBAC study. 11 The baseline IOBAC column study was also performed over a 4-week continuous test period under psychrophilic ambient conditions (at 10 °C) under which biodegradation rates were expected to be lower. By the third week of testingthe time at which the 23 °C had reached stable operationthe average adsorption measured as % COD removal was 50% (642 mg L −1 COD) for the 180 min effluent samples and 40% (513 mg L −1 COD) for the 270 min effluent samples (Fig.…”

Granular media filtration for on-site treatment of greywater: A review

“…Ellis & Wood (1985) recommends a minimum depth of 30 cm for filter media for efficient removal of different physicochemical and microbial parameters and hence, most studies utilized a minimum media depth of 30 cm (Aizenchtadt et al 2009;Zipf et al 2016;Thompson et al 2020;Sharaf & Liu 2021). However, a few studies while assessing the feasibility of compact systems used media depth of less than 30 cm (Griffioen & Natha 2013;Ward et al 2015;Prabha et al 2021). Removal of most of the contaminants occurs in the top 10-30 cm depth of filter media.…”

Water Reclamation and Reuse

“…Ward et al (2015) investigated the treatment of gray water using biological activated carbon (BAC) and complementary technologies. BAC performed well over test periods as long as six months.…”