scholarly journals Treatment of Polluted Urban Surface Waters by Sponge Based Aerobic Biofilm Reactor: Purification Performances and Resilience

2021 ◽  
Author(s):  
Shangwei He ◽  
Na Song ◽  
Zongbao Yao ◽  
Helong Jiang
Keyword(s):  
Organic Matter ◽  
Surface Waters ◽  
Carbon Sources ◽  
Biofilm Reactor ◽  
Urban Surface ◽  
Land Occupation ◽  
N Removal ◽  
Water Cycling ◽  
Polyurethane Sponge ◽  
Biodegradable Organic Matter

Abstract Surface waters are suffering continuous discharging of pollutions, and low DO and black-odorous were easily formed, especially in those slow-flowing urban lakes and enclosed small ponds. In-situ treatment by artificial aeration or water cycling with a combination of polyurethane sponge as biofilm carriers can disentangle this situation without any land occupation. Long-term continuous experiments (187 days) showed that indigenous microorganisms in urban surface waters could form biofilms in the novel style of sponge-based aerobic biofilm reactors (SABRs). In urban lake waters treatment, the purification performances of SABRs were stable and resilient as the NH4+-N and NO2−-N removals were steady, even facing the abrupt increase of NH4+-N and NO2−-N concentrations in influent. Enhancing the polyurethane sponge filling ratios in SABRs can reduce DO but did not affect NH4+-N removal. SABRs were also able to treat enclosed surface waters or black-odorous waterbodies. Combined SABRs with water cycling, NH4+-N removal time was shorter than the time needed by water cycling when biodegradable organic matter was not present. The massive biodegradable organic matter could inhibit nitrification and prolong the purification time. Further results showed that organic matter could be used as carbon sources to eliminate the produced NO3−-N in SABRs. Therefore, the developed new bioreactor could act as one effective way for treating N-polluted urban surface waters.

Degradation of organic matter from domestic wastewater with loofah sponge biofilm reactor

2012 ◽  
Vol 65 (1) ◽  
pp. 190-195 ◽  
Author(s):  
Liwei Zhang ◽  
Ken Sun ◽  
Na Hu
Keyword(s):  
Organic Matter ◽  
Domestic Wastewater ◽  
Biofilm Reactor ◽  
Present System ◽  
Support Material ◽  
N Removal ◽  
Loofah Sponge ◽  
Natural Support ◽  
Influence Parameter ◽  
Removal Efficiencies

A laboratory-scale oxic biofilm reactor using loofah sponge as support material was carried out to study its start-up characteristics and the optimum operation parameters in removing organic matter and nitrogen from domestic wastewater. It took no more than 10 days to complete microbiological cultivation and acclimation, indicating that the natural loofah sponge was a superior support material compared with some conventional ones. The influence parameter experiments showed that the hydraulic retention time (HRT) had a significant influence on the COD and NH3-N removal efficiencies, the average COD and NH3-N removal efficiencies were 83.7 and 96.9% respectively when the temperature was 25 ± 2 °C, the influent flow rate was 0.21 L/h and the HRT was 7.5 h. The loofah sponge biofilm system had a strong tolerance to organic shock loading in the present experiment. Additionally, it was found that domestic wastewater could be preferably treated with 88.9% of COD and 98.7% of NH3-N removal efficiencies with the corresponding influent concentrations of 260.0 and 26.8 mg/L, respectively. The observations obtained in the present study indicated that the loofah sponge was an excellent natural support material, potentially feasible for the present system for the treatment of the decentralized domestic wastewater.

scholarly journals Anammox bacteria drive fixed nitrogen loss in hadal trench sediments

2021 ◽  
Vol 118 (46) ◽  
pp. e2104529118
Author(s):  
Bo Thamdrup ◽  
Clemens Schauberger ◽  
Morten Larsen ◽  
Blandine Trouche ◽  
Lois Maignien ◽  
...  
Keyword(s):  
Organic Matter ◽  
Surface Waters ◽  
Nitrogen Loss ◽  
Sediment Surface ◽  
Anammox Bacteria ◽  
Nitrogen Transformations ◽  
Production Rates ◽  
Fixed Nitrogen ◽  
N Removal ◽  
Aerobic Nitrification

Benthic N2 production by microbial denitrification and anammox is the largest sink for fixed nitrogen in the oceans. Most N2 production occurs on the continental shelves, where a high flux of reactive organic matter fuels the depletion of nitrate close to the sediment surface. By contrast, N2 production rates in abyssal sediments are low due to low inputs of reactive organics, and nitrogen transformations are dominated by aerobic nitrification and the release of nitrate to the bottom water. Here, we demonstrate that this trend is reversed in the deepest parts of the oceans, the hadal trenches, where focusing of reactive organic matter enhances benthic microbial activity. Thus, at ∼8-km depth in the Atacama Trench, underlying productive surface waters, nitrate is depleted within a few centimeters of the sediment surface, N2 production rates reach those reported from some continental margin sites, and fixed nitrogen loss is mainly conveyed by anammox bacteria. These bacteria are closely related to those known from shallow oxygen minimum zone waters, and comparison of activities measured in the laboratory and in situ suggest they are piezotolerant. Even the Kermadec Trench, underlying oligotrophic surface waters, exhibits substantial fixed N removal. Our results underline the role of hadal sediments as hot spots of deep-sea biological activity, revealing a fully functional benthic nitrogen cycle at high hydrostatic pressure and pointing to hadal sediments as a previously unexplored niche for anaerobic microbial ecology and diagenesis.

A PCR-DGGE Approach to Evaluate the Influence of Environment Materials for Civil Engineering-Different Carbon Sources on a Catching Bed Biofilm Reactor in Start-up Phase

2012 ◽  
Vol 568 ◽  
pp. 260-264
Author(s):  
Yan Zhang ◽  
Li Li Wang ◽  
Zheng Yang Yang ◽  
Xu Ying Zhao ◽  
Huan Guang Liu ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Civil Engineering ◽  
Carbon Sources ◽  
Biofilm Reactor ◽  
Formation Stage ◽  
N Removal ◽  
Start Up ◽  
Different Types ◽  
Removal Efficiencies ◽  
Two Stages

In this study, the effect of environment materials for civil engineering was investigated through two sets of parallel reactors with sodium acetate and starch as carbon source separately. The reactors were started up by two stages, including biofilm formation stage and biofilm domestication stage. In biofilm domestication stage, the average removal efficiencies of COD were 88.84% and 88.78% respectively. NH4+-N removal efficiencies were reached at 99.28% and 91.90%. Total nitrogen（TN）removal efficiencies were 45.25% and 45.45%. By PCR-DGGE, it was found that there were high similarities between biofilm and suspension in the reactors. Different types of carbon sources enriched different types of microorganisms. The study can provide references for studying simultaneous nitrification and denitrification（SND）and optimizing carbon sources.

The Use of Anoxic Selectors for the Control of Low F/M Activated Sludge Bulking

1989 ◽  
Vol 21 (6-7) ◽  
pp. 609-619 ◽  
Author(s):  
Y.-J. Shao ◽  
David Jenkins
Keyword(s):  
Organic Matter ◽  
Activated Sludge ◽  
Pilot Plant ◽  
Detention Time ◽  
Substrate Removal ◽  
Batch System ◽  
Sludge Bulking ◽  
N Removal ◽  
Soluble Substrate ◽  
Activated Sludge Systems

Laboratory and pilot plant experiments on anoxic selector activated sludge systems were conducted on two wastewaters in some cases supplemented with nitrate, acetate or glucose. To prevent bulking sufficient anoxic selector detention time and nitrate levels must be available to reduce selector effluent soluble COD to below 100 mg/l and to reduce readily metabolizable organic matter to virtually zero (< 1 mg/l). Soluble COD/NO3-N removal stoichiometry is in the range 6.0-6.7. Selector systems have elevated soluble substrate removal and denitrification rates compared to CSTR systems. These rates are not affected greatly by temperature (20-25°C) for CSTR sludges but are for selector sludges. Upon exhaustion of nitrate in a selector soluble COD leaks out of the activated sludge in significant amounts. Thiothrix sp. and type 021N denitrify only to NO2 and at much slower rates than Zoogloearamigera does to N2. A sequencing batch system provides an optimistic estimate of the SVI that can be obtained by an anoxic selector system.

Denitrification in a Carbon and Nitrogen Removal System for Leachate Treatment: Performance of a Upflow Sludge Blanket (USB) Reactor

1999 ◽  
Vol 40 (8) ◽  
pp. 145-151 ◽  
Author(s):  
Liliana Borzacconi ◽  
Gisela Ottonello ◽  
Elena Castelló ◽  
Heber Pelaez ◽  
Augusto Gazzola ◽  
...  
Keyword(s):  
Complete System ◽  
Carbon Sources ◽  
Uasb Reactor ◽  
Leachate Treatment ◽  
N Removal ◽  
Start Up ◽  
Aerobic Reactor ◽  
C And N ◽  
Reactor Operating ◽  
Removal System

The performance of a bench scale upflow sludge bed (USB) denitrifying reactor was evaluated in order to integrate it into a C and N removal system for Sanitary Landfill Leachate. The raw leachate used presented COD and NH4-N average values of 30000 mg/l and 1000 mg/l, respectively. The complete system comprises in addition an UASB reactor and a nitrifying RBC. A portion of the aerobic reactor effluent was recycled into the denitrification stage and some raw leachate was also added as an additional C source. In order to obtain operating parameters the denitrifying reactor was operated alone. Sludge from an aerobic reactor (RBC) treating raw leachate was used as inoculum. Shortly after the start up, good granulation of the sludge bed was observed. Using raw leachate and UASB outlet as carbon sources with COD/NO3-N ratios of 4 and 12, respectively, denitrification efficiencies of about 90% were reached. A sludge yield of 0.16 gVSS/gCODremoved was obtained operating with raw leachate. For the anoxic reactor operating in the complete system, denitrification efficiencies of 90% were also achieved. A nitrogen gas recycle was a successful way to avoid frequently observed sludge bed rising problems.

Antimicrobial resistance genes are enriched in aerosols near impacted urban surface waters in La Paz, Bolivia

2021 ◽  
Vol 194 ◽  
pp. 110730
Author(s):  
Olivia Ginn ◽  
Dennis Nichols ◽  
Lucas Rocha-Melogno ◽  
Aaron Bivins ◽  
David Berendes ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Surface Waters ◽  
Urban Surface ◽  
La Paz ◽  
Antimicrobial Resistance Genes

Influence of C/N Ratio on SND and Microbiological Analysis in Catching Bed Biofilm Reactor Using Acrylic Resin Fiber as Carrier Materials in Civil Engineering

2012 ◽  
Vol 568 ◽  
pp. 89-93
Author(s):  
Yan Zhang ◽  
Zheng Yang Yang ◽  
Li Li Wang ◽  
Xu Ying Zhao ◽  
Huan Guang Liu ◽  
...  
Keyword(s):  
Civil Engineering ◽  
Removal Rate ◽  
Acrylic Resin ◽  
Biofilm Reactor ◽  
Easy Access ◽  
Fish Analysis ◽  
Microbiological Analysis ◽  
Ammonia Oxidizing Bacteria ◽  
N Removal ◽  
Carrier Materials

In this study, effect of C/N ratio on denitrification were investigated using four sets of parallel catching bed reactors, which were using acrylic resin fiber (ARF) as carrier materials. The results indicate that this process which was used in wastewater treatment of civil engineering can get better COD and nitrogen removing performance. NH4+-N removal rate reduced with the increasing of C/N ratio, and the average removal rate of COD and the total nitrogen (TN) increased when C/N ratio is increased. When C/N ratio exceeded 12, TN removal rate has no obvious growing. Meanwhile, fluorescent in situ hybridization (FISH) analysis indicated that the biomass in the biofilm were much richer than which in the suspension, and the ammonia oxidizing bacteria have a easy access to be dominant bacterial community in lower C/N ratio.

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