title: Leaching techniques to remove metals and potentially hazardous nutrients from trout farm sludge.
abstract: A fish farm sludge high in P (2-6% w/w as dry matter), Fe (5-7%), C (40-50%) and N (0.8-4%) was subjected to a series of acid leaching treatments using HCl, organic acids, and biologically mediated acid production. Additions of biodegradable organic acid solubilized heavy metals better than HCl, while additions of 1.5% w/v glucose followed by 7 day incubation stabilized the sludge releasing 92% P, 100% Fe. The use of homo-lactic Lactobacillus plantarum starter cultures were more effective than hetero-lactic Lactobacillus buchneri, solubilizing 81.9% P, 92.2% Fe, 93.0% Zn and 96.4% Ca in the sludge. The anaerobic sludge-glucose fermentation using L. plantarum produced a leached sludge that has low heavy metal and nutrient content while affording the recovery of nutrients. The potential of these methods for practical application are briefly discussed.
authors.affiliation: Centre for Complex Fluid Processing (CCFP), School of Engineering, Swansea University, Talbot building, Singleton Park, Swansea, Wales SA2 8PP, UK.
authors.forename: I S
authors.initials: IS
authors.lastname: Jung
authors.forename: R W
authors.initials: RW
authors.lastname: Lovitt
mesh_terms: D019342:Acetic Acid / Q000494:pharmacology; D000693:Anaerobiosis / Q000187:drug effects; D000818:Animals; D001673:Biodegradation, Environmental / Q000187:drug effects; D003718:Denmark; D005285:Fermentation / Q000187:drug effects; D005398:Fisheries; D005947:Glucose / Q000494:pharmacology; D015386:Hazardous Substances / Q000302:isolation & purification*; D006851:Hydrochloric Acid / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D019344:Lactic Acid / Q000494:pharmacology; D007778:Lactobacillus / Q000187:drug effects; D008670:Metals / Q000302:isolation & purification*; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology; D013997:Time Factors; D017186:Titrimetry; D014337:Trout / Q000254:growth & development*; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D015386:Hazardous Substances; D008670:Metals; D012722:Sewage; D014874:Water Pollutants, Chemical; D019344:Lactic Acid; D005947:Glucose; D019342:Acetic Acid; D006851:Hydrochloric Acid