Nutrient removal by the integrated use of high rate algal ponds and macrophyte systems in China

2003 ◽  
Vol 48 (2) ◽  
pp. 251-257 ◽  
Author(s):  
P. Chen ◽  
Q. Zhou ◽  
J. Paing ◽  
H. Le ◽  
B. Picot
Keyword(s):  
Nutrient Removal ◽  
Linear Models ◽  
Pilot Scale ◽  
High Rate ◽  
Temperate Climate ◽  
Annual Average ◽  
Good Efficiency ◽  
Climate Conditions ◽  
High Rate Algal Ponds ◽  
Nutrient Removal Efficiency

High Rate Algal Ponds (HRAP) were operated at pilot scale to investigate the performance of HRAP under the temperate climate conditions of Shanghai, China. The results indicated that the HRAP gave good efficiency for nutrient removal, especially during summer. With a retention time of 4 or 8d according to the season, the annual average removal efficiencies for COD, NH4-N and PO4-P were 50%, 87% and 40%, respectively. The multi-factor linear models showed the relationships between nutrient removal efficiency and influencing factors. Using a macrophyte pond to separate algae from HRAP can achieve concentrations of COD, TP and TKN in the effluent at around 50 mg/L, 1.5 mg/L and 5 mg/L respectively.

Viability of nematode eggs in high rate algal ponds: the effect of physico-chemical conditions

2000 ◽  
Vol 42 (10-11) ◽  
pp. 371-374 ◽  
Author(s):  
S. Araki ◽  
J. M. González ◽  
E. de Luis ◽  
E. Bécares
Keyword(s):  
Hydraulic Retention Time ◽  
Pilot Scale ◽  
High Rate ◽  
Sterile Water ◽  
Egg Viability ◽  
High Rate Algal Ponds ◽  
Helminth Eggs ◽  
Physico Chemical ◽  
Nematode Eggs ◽  
Chemical Conditions

The viability of Parascaris equorum eggs was studied in two experimental pilot-scale high-rate algal ponds (HRAPs) working in parallel with 4 and 10 days hydraulic retention time respectively. Semi-permeable bags of cellulose (15000 daltons pore size) were used to study the effect of physico-chemical conditions on the survival of these helminth eggs. Three thousand eggs were used in each bag. Replicates of these bags were submerged for 4 and 10 days in the HRAPs and egg viability was compared with that in control bags submerged in sterile water. After 4 days exposure, 60% reduction in viability was achieved, reaching 90% after 10 days, much higher than the 16% and 25% found in the control bags for 4 and 10 days respectively. Ionic conditions of the HRAP may have been responsible for up to 50–60% of the egg mortality, suggesting that mortality due to the ionic environment could be more important than physical retention and other potential removal factors.

Algal biofuels from wastewater treatment high rate algal ponds

2011 ◽  
Vol 63 (4) ◽  
pp. 660-665 ◽  
Author(s):  
R. J. Craggs ◽  
S. Heubeck ◽  
T. J. Lundquist ◽  
J. R. Benemann
Keyword(s):  
Wastewater Treatment ◽  
Nutrient Removal ◽  
Large Scale ◽  
Low Cost ◽  
Algal Species ◽  
Climatic Conditions ◽  
Biofuel Production ◽  
High Rate ◽  
Algal Production ◽  
High Rate Algal Ponds

This paper examines the potential of algae biofuel production in conjunction with wastewater treatment. Current technology for algal wastewater treatment uses facultative ponds, however, these ponds have low productivity (∼10 tonnes/ha.y), are not amenable to cultivating single algal species, require chemical flocculation or other expensive processes for algal harvest, and do not provide consistent nutrient removal. Shallow, paddlewheel-mixed high rate algal ponds (HRAPs) have much higher productivities (∼30 tonnes/ha.y) and promote bioflocculation settling which may provide low-cost algal harvest. Moreover, HRAP algae are carbon-limited and daytime addition of CO2 has, under suitable climatic conditions, the potential to double production (to ∼60 tonnes/ha.y), improve bioflocculation algal harvest, and enhance wastewater nutrient removal. Algae biofuels (e.g. biogas, ethanol, biodiesel and crude bio-oil), could be produced from the algae harvested from wastewater HRAPs, The wastewater treatment function would cover the capital and operation costs of algal production, with biofuel and recovered nutrient fertilizer being by-products. Greenhouse gas abatement results from both the production of the biofuels and the savings in energy consumption compared to electromechanical treatment processes. However, to achieve these benefits, further research is required, particularly the large-scale demonstration of wastewater treatment HRAP algal production and harvest.

Improved microalgal productivity and nutrient removal through operating wastewater high rate algal ponds in series

2020 ◽  
Vol 47 ◽  
pp. 101850 ◽  
Author(s):  
Donna L. Sutherland ◽  
Jason Park ◽  
Peter J. Ralph ◽  
Rupert J. Craggs
Keyword(s):  
Nutrient Removal ◽  
High Rate ◽  
High Rate Algal Ponds ◽  
In Series

Nutrient removal in wastewater treatment high rate algal ponds with carbon dioxide addition

2011 ◽  
Vol 63 (8) ◽  
pp. 1758-1764 ◽  
Author(s):  
J. B. K. Park ◽  
R. J. Craggs
Keyword(s):  
Nitrogen Removal ◽  
Organic Nitrogen ◽  
Inorganic Nitrogen ◽  
Nitrogen Loss ◽  
Bacterial Biomass ◽  
Pilot Scale ◽  
High Rate ◽  
High Rate Algal Ponds ◽  
Carbon Dioxide Addition ◽  
Co2 Addition

The influence of CO2 addition to high rate algal ponds (HRAPs) on nitrogen removal was investigated using two pilot-scale HRAPs operated with different hydraulic retention times (HRT: 4 and 8 days), and was compared to the nitrogen removal by the 8-day HRT pond before CO2 addition was installed. Nitrogen balances were calculated by partitioning total nitrogen into organic and inorganic nitrogen (NH+4-N and NO−3-N), and by separation of the organic nitrogen into particulate (PON) and dissolved organic nitrogen (DON). PON was further divided into algal organic nitrogen (AON) and bacteria organic nitrogen (BON) to investigate nitrogen mass flow in the HRAPs. This research shows that the proportion of algae in the algal/bacterial biomass in the longer 8-day HRT HRAP8d (55.6%) was appreciably lower than that in the shorter 4-day HRT HRAP4d (80.5%) when CO2 was added to control the maximum pH to <8.0 during the summer. Higher bacterial biomass in the longer 8-day HRT HRAP corresponded with higher nitrification rates, indicating that the longer 8-day HRT in the summer was detrimental for two reasons: lower algal productivity and increased nitrogen loss through nitrification/denitrification. Overall nitrogen removal of ~60% in the HRAPs with CO2 addition was mainly achieved by algal assimilation followed by sedimentation in the settling unit.

Enhancing biomass energy yield from pilot-scale high rate algal ponds with recycling

2013 ◽  
Vol 47 (13) ◽  
pp. 4422-4432 ◽  
Author(s):  
J.B.K. Park ◽  
R.J. Craggs ◽  
A.N. Shilton
Keyword(s):  
Pilot Scale ◽  
Biomass Energy ◽  
High Rate ◽  
Energy Yield ◽  
High Rate Algal Ponds

Adapting UASB technology for sewage treatment in Palestine and Jordan

2008 ◽  
Vol 57 (3) ◽  
pp. 361-366 ◽  
Author(s):  
Nidal Mahmoud ◽  
Grietje Zeeman ◽  
JulesB. van Lier
Keyword(s):  
Sewage Treatment ◽  
Cost Effective ◽  
Pilot Scale ◽  
High Rate ◽  
Uasb Reactor ◽  
Temperate Climate ◽  
Model Calculations ◽  
Methanogenic Activity ◽  
Operational Conditions ◽  
Sludge Stabilization

High rate anaerobic technologies offer cost-effective solutions for “sewage” treatment in the temperate climate of Palestine and Jordan. However, local sewage characteristics demand amendments to the conventional UASB reactor design. A solution is found in a parallel operating digester unit that stabilises incoming solids and enriches the UASB sludge bed with methanogenic activity. The digester operational conditions were assessed by operating eight CSTRs fed with primary sludge. The results showed a high degree of sludge stabilization in the parallel digesters at SRTs≥10 and 15 days at process temperatures of 35 and 25°C, respectively. The technical feasibility of the UASB-digester combination was demonstrated by continuous flow pilot-scale experiments. A pilot UASB reactor was operated for 81 days at 6 hours HRT and 15°C and was fed with raw domestic sewage. This period was subsequently followed by an 83 day operation period incorporating a parallel digester unit, which was operated at 35°C. The UASB-digester combination achieved removal efficiencies of total, suspended, colloidal and dissolved CODs of respectively 66, 87, 44 and 30%. Preliminary model calculations indicated that a total reactor volume of the UASB-digester system corresponding to 8.6 hours HRT might suffice for sewage treatment in Palestine.

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