title: Performance and granulation in an upflow anaerobic sludge blanket (UASB) reactor treating saline sulfate wastewater.
abstract: An upflow anaerobic sludge blanket reactor was employed to treat saline sulfate wastewater. Mesophilic operation (35 ± 0.5 °C) was performed with hydraulic retention time fixed at 16 h. When the salinity was 28 g L(-1), the chemical oxygen demand and sulfate removal efficiencies were 52 and 67 %, respectively. The salinity effect on sulfate removal was less than that on organics removal. The methane productions were 887 and 329 cm(3) L(-1) corresponding to the NaCl concentrations of 12 and 28 g L(-1), respectively. High salinity could stimulate microbes to produce more extracellular polymeric substances (EPSs) and granulation could be performed better. Besides, with the high saline surroundings, a great deal of Na(+) compressed the colloidal electrical double-layer, neutralized the negative charge of the sludge particles and decreased their electrostatic repulsion. The repulsion barrier disappeared and coagulation took place. The maximum size of granules was 5 mm, which resulted from the coupled triggering forces of high EPSs and Na(+) contents. Sulfate-reducing bacteria (SRB) were dominant in the high saline surroundings while the methane-producing archaea dominated in the low saline surroundings. The SRB were affected least by the salinity.
authors.affiliation: School of Chemical and Environmental Engineering, Qingdao University, Qingdao, People's Republic of China, ljin0532@126.com.
authors.forename: Jin
authors.initials: J
authors.lastname: Li
authors.forename: Lian
authors.initials: L
authors.lastname: Yu
authors.forename: Deshuang
authors.initials: D
authors.lastname: Yu
authors.forename: Dan
authors.initials: D
authors.lastname: Wang
authors.forename: Peiyu
authors.initials: P
authors.lastname: Zhang
authors.forename: Zhongguang
authors.initials: Z
authors.lastname: Ji
mesh_terms: D001105:Archaea / Q000145:classification / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D016650:Fluorescein-5-isothiocyanate; D017404:In Situ Hybridization, Fluorescence; D008697:Methane / Q000096:biosynthesis; D054712:Salinity; D055049:Salt Tolerance / Q000502:physiology; D012965:Sodium Chloride / Q000494:pharmacology; D055672:Static Electricity; D013431:Sulfates / Q000378:metabolism*; D016999:Sulfur-Reducing Bacteria / Q000145:classification / Q000187:drug effects / Q000302:isolation & purification / Q000378:metabolism*; D062065:Wastewater / Q000737:chemistry / Q000382:microbiology*
chemical_list: D016650:Fluorescein-5-isothiocyanate; D008697:Methane; D012965:Sodium Chloride; D013431:Sulfates; D062065:Wastewater