Table 2.

Reported metal concentrations that cause inhibition of biodegradation of chlorinated organic contaminants under anaerobic conditions.

Metal	Organic	Lowest metal concentration	Microbe(s) studied	Environment	pH	Reference
Cd2+	TCA	0.01 mg/L a	Indigenous community	Laboratory soil microcosms containing rice paddy and bottomland hardwood soils	6.9–7.4	[95]
Cd2+	TCA	0.2 mg/L a	Indigenous community	Laboratory soil microcosms containing organic matter- rich soil	6.8	[95]
Cd2+	2-CP; 3-CB	0.5–1.0 mg/L b	Indigenous community	Aqueous sediment enriched in anaerobic growth medium	7.0	[15]
Cd2+	2-CP; 3-CP	20 mg/L b	Indigenous community	Sediment slurry	7.0	[73]
Cr 6+	2-CP; 3-CB	0.01–0.5 mg/L b	Indigenous community	Aqueous sediment enriched in anaerobic growth medium	7.0	[15]
Cu2+	2-CP, 3-CB	0.1–1.0 mg/L b	Indigenous community	Aqueous sediment enriched in anaerobic growth medium	7.0	[15]
Cu2+	2-CP; 3-CP	20 mg/L b	Indigenous community	Sediment slurry	7.0	[73]
Cr 6+	2-CP; 3-CP	20 mg/L b	Indigenous community	Sediment slurry	7.0	[73]
Pb2+	HCB	0.001 mg/g b	Indigenous community	Microcosms containing contaminated sediment	NR	[116]
Hg2+	2-CP; 3-CB	0.1–1.0 mg/L b	Indigenous community	Aqueous sediment enriched in anaerobic growth medium	7.0	[15]
Zn2+	PCP	2 mg/L b	Indigenous community	Anaerobic digester sludge in a liquid medium containing 0.6 mM phosphate	NR	[96]
Zn2+	PCP	8.6 mg/L b	Indigenous community	Anaerobic enrichment cultures in serum bottles	NR	[72]

3-CB, 3-chlorobenzoate; 2-CP, 2-chlorophenol; 3-CP, 3-chlorophenol; HCB, Hexachlorobenzene; PCP, Pentachlorophenol; NR, not reported; TCA, Trichloroaniline.

^aValue represents solution-phase concentration of metal present in system;

^bValue represents total metal added to system.