Effect of hydraulic residence time on biological sulphate reduction and elemental sulphur recovery in a single-stage hybrid linear flow channel reactor

2020 ◽  
Vol 162 ◽  
pp. 107717 ◽  
Author(s):  
T.S. Marais ◽  
R.J. Huddy ◽  
S.T.L. Harrison ◽  
R.P. van Hille
Keyword(s):  
Residence Time ◽  
Flow Channel ◽  
Elemental Sulphur ◽  
Single Stage ◽  
Sulphate Reduction ◽  
Channel Reactor ◽  
Hydraulic Residence Time ◽  
Linear Flow ◽  
Sulphur Recovery

scholarly journals Demonstration of simultaneous biological sulphate reduction and partial sulphide oxidation in a hybrid linear flow channel reactor

2019 ◽  
Author(s):  
TS Marais ◽  
RJ Huddy ◽  
STL Harrison ◽  
RP van Hille
Keyword(s):  
Rapid Development ◽  
Reduction Rate ◽  
Cost Effective ◽  
Flow Channel ◽  
Elemental Sulphur ◽  
Sulphate Reduction ◽  
Channel Reactor ◽  
Linear Flow ◽  
Sulphide Oxidation ◽  
Concept Evaluation

AbstractSemi-passive remediation systems have the potential to treat low-volume, sulphate-rich, mining impacted waters in a cost-effective and sustainable way. This paper describes the “proof of concept” evaluation of a hybrid linear flow channel reactor, capable of sustaining efficient biological sulphate reduction and partial oxidation of the sulphide product to elemental sulphur. Key elements include the presence of a sulphate-reducing microbial community, immobilised onto carbon fibres and the rapid development of a floating biofilm at the air-liquid interface. The biofilm consists of heterotrophic species and autotrophic sulphide oxidisers. It impedes oxygen mass transfer into the bulk volume and creates a suitable pH-redox microenvironment for partial sulphide oxidation. Demonstration of the concept was successful, with near 20 complete reduction of the sulphate in the feed (1 g/l), effective management of the sulphide generated (95-100% removal) and recovery of a portion of the sulphur by harvesting the elemental-sulphur-rich biofilm. The biofilm re-formed within 24 hours of harvesting, with no decrease in volumetric sulphate reduction rate during this period. Colonisation of the carbon microfibers by sulphate reducing bacteria ensured biomass retention, suggesting the reactor could remain effective at high volumetric flow rates.

Effects of reactor geometry and electron donor on performance of the hybrid linear flow channel reactor

2020 ◽  
Vol 197 ◽  
pp. 105462
Author(s):  
T.S. Marais ◽  
R.J. Huddy ◽  
R.P. van Hille ◽  
S.T.L. Harrison
Keyword(s):  
Electron Donor ◽  
Flow Channel ◽  
Channel Reactor ◽  
Linear Flow ◽  
Reactor Geometry

Impact of hydraulic residence time on nitrate removal in pilot-scale woodchip bioreactors

2019 ◽  
Vol 237 ◽  
pp. 424-432 ◽  
Author(s):  
E.A. Martin ◽  
M.P. Davis ◽  
T.B. Moorman ◽  
T.M. Isenhart ◽  
M.L. Soupir
Keyword(s):  
Residence Time ◽  
Nitrate Removal ◽  
Pilot Scale ◽  
Hydraulic Residence Time

Transformation of a Petroleum Mixture in Biofilms

1992 ◽  
Vol 26 (3-4) ◽  
pp. 637-646 ◽  
Author(s):  
E. J. Bouwer ◽  
C. T. Chen ◽  
Y.-H. Li
Keyword(s):  
Residence Time ◽  
Petroleum Hydrocarbons ◽  
Reaction Rates ◽  
Hydrocarbon Contamination ◽  
Waste Oil ◽  
Column Studies ◽  
Hydraulic Residence Time ◽  
Methyl Naphthalene ◽  
Aerobic And Anaerobic ◽  
Underlying Soil

Petroleum hydrocarbons from a lagoon storing waste oil in New Jersey have contaminated underlying soil and groundwater. Biofilm column studies were performed to investigate biotransformation of the petroleum mixture under aerobic and anaerobic conditions. The waste oil at concentrations ranging between 10 and 100 mg/L was continuously applied to glass bead columns that resembled porous media. The majority of the alkylbenzenes and polynuclear aromatic compounds identified in the oil mixture were simultaneously biotransformed by aerobic biofilms within a 2-hour hydraulic residence time. In a methanogenic biofilm column with 2-day hydraulic residence time, the mixture of hydrocarbons was initially removed by sorption with complete breakthrough occurring after 300 days of operation. After 600 days, the methanogenic biofilm acclimated to several of the specific hydrocarbon components, and effluent concentrations decreased due to apparent biotransformation. Radiotracer studies with toluene, naphthalene, and 2-methyl-naphthalene indicated partial mineralization to CO2 under both aerobic and methanogenic conditions. Reaction rates observed in the laboratory biofilms indicate that biotransformation could be an effective process to control hydrocarbon contamination in the environment.

scholarly journals Assessment of a low-cost, point-of-use, ultraviolet water disinfection technology

2007 ◽  
Vol 6 (1) ◽  
pp. 53-65 ◽  
Author(s):  
Sarah A. Brownell ◽  
Alicia R. Chakrabarti ◽  
Forest M. Kaser ◽  
Lloyd G. Connelly ◽  
Rachel L. Peletz ◽  
...  
Keyword(s):  
Rural Communities ◽  
Residence Time ◽  
Low Cost ◽  
Plug Flow ◽  
Field Studies ◽  
Water Disinfection ◽  
Galvanized Steel ◽  
Hydraulic Residence Time ◽  
Biological Assays ◽  
Point Of Use

We describe a point-of-use (POU) ultraviolet (UV) disinfection technology, the UV Tube, which can be made with locally available resources around the world for under $50 US. Laboratory and field studies were conducted to characterize the UV Tube's performance when treating a flowrate of 5 L/min. Based on biological assays with MS2 coliphage, the UV Tube delivered an average fluence of 900±80 J/m2 (95% CI) in water with an absorption coefficient of 0.01 cm−1. The residence time distribution in the UV Tube was characterized as plug flow with dispersion (Peclet Number = 19.7) and a mean hydraulic residence time of 36 s. Undesirable compounds were leached or produced from UV Tubes constructed with unlined ABS, PVC, or a galvanized steel liner. Lining the PVC pipe with stainless steel, however, prevented production of regulated halogenated organics. A small field study in two rural communities in Baja California Sur demonstrated that the UV Tube reduced E. coli concentrations to less than 1/100 ml in 65 out of 70 samples. Based on these results, we conclude that the UV Tube is a promising technology for treating household drinking water at the point of use.

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