Combined Artificial Wetland and High Rate Algal Pond for Wastewater Treatment and Protein Production

1989 ◽  
Vol 21 (6-7) ◽  
pp. 659-668 ◽  
Author(s):  
A. Wood ◽  
J. Scheepers ◽  
M. Hills
Keyword(s):  
Wastewater Treatment ◽  
Green Alga ◽  
Nutrient Removal ◽  
Protein Production ◽  
Pilot Scale ◽  
High Rate ◽  
Residence Times ◽  
Surface Loading ◽  
Artificial Wetland ◽  
Effluent Stream

The potential to optimize wastewater utilization, whilst achieving satisfactory nutrient removal has been investigated through a simple system combining an Artificial Wetland with a High Rate Algal Pond (HRAP). Receiving septic sewage at a surface loading equivalent to 13.5 cm/day the Wetland achieved COD removals of 59.2%, NH4−N of 34,6%, PO4−P of 31.9% and SS of 78%. The HRAP selectively cultivated an easily harvestable filamentous green alga through a combination of short hydraulic residence times (< days), and microscreens as selectors over the effluent stream. Passage of the effluent through this stage permitted COD removal to increase to 79.4%, NH4−N to 82.8% and PO4−P to 54.1%, whilst generating a highly proteinaceous (42% by wt) biomass at a rate of approximately 50 tons/hectare/year. This paper discusses the performance of the pilot scale facility over a twelve month period, identifying biological and operational influences on the system, and the physiological mechanics by which the wastewater treatment is accomplished.

Tilapia rearing with high rate algal pond effluent: ammonia surface loading rates and stocking densities effects

2018 ◽  
Vol 78 (1) ◽  
pp. 49-56
Author(s):  
I. A. Sánchez ◽  
R. K. X. Bastos ◽  
E. A. T. Lana
Keyword(s):  
Weight Gain ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Ammonia Nitrogen ◽  
High Rate ◽  
Surface Loading ◽  
Loading Rates ◽  
Total Weight Gain ◽  
Low Weight ◽  
Total Ammonia

Abstract In two pilot-scale experiments, fingerlings and juvenile of tilapia were reared in high rate algal pond (HRAP) effluent. The combination of three different total ammonia nitrogen (TAN) surface loading rates (SLR1 = 0.6, SLR2 = 1.2; SLR3 = 2.4 kg TAN·ha−1·d−1) and two fish stocking densities (D1 = 4 and D2 = 8 fish per tank) was evaluated during two 12-week experiments. Fingerlings total weight gain varied from 4.9 to 18.9 g, with the highest value (equivalent to 0.225 g·d−1) being recorded in SLR2-D1 treatment; however, high mortality (up to 67%) was recorded, probably due to sensitivity to ammonia and wide daily temperature variations. At lower water temperatures, juvenile tilapia showed no mortality, but very low weight gain. The fish rearing tanks worked as wastewater polishing units, adding the following approximate average removal figures on top of those achieved at the HRAP: 63% of total Kjeldahl nitrogen; 54% of ammonia nitrogen; 42% of total phosphorus; 37% of chemical oxygen demand; 1.1 log units of Escherichia coli.

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.

Effects of operation parameters on nutrient removal from wastewater and high-protein biomass production in a duckweed-based (Lemma aequinoctialis) pilot-scale system

2014 ◽  
Vol 70 (7) ◽  
pp. 1195-1204 ◽  
Author(s):  
Yonggui Zhao ◽  
Yang Fang ◽  
Yanling Jin ◽  
Jun Huang ◽  
Shu Bao ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Biomass Production ◽  
Water Depth ◽  
Nutrient Removal ◽  
Removal Rate ◽  
Pilot Scale ◽  
Coverage Rate ◽  
High Protein ◽  
Dianchi Lake ◽  
Operation Conditions

The effects of water depth, coverage rate and harvest regime on nutrient removal from wastewater and high-protein biomass production were assessed in a duckweed-based (Lemna aequinoctialis) pilot-scale wastewater treatment system (10 basins × 12 m2) that is located near Dianchi Lake in China. The results indicated that a water depth of 50 cm, a coverage rate of 150% and a harvest regime of 4 days were preferable conditions, under which excellent records of high-protein duckweed (dry matter production of 6.65 g/m2/d with crude protein content of 36.16% and phosphorus content of 1.46%) were obtained at a temperature of 12–21 °C. At the same time, the system achieved a removal efficiency of 66.16, 23.1, 48.3 and 76.52% for NH4+-N, TN, TP and turbidity, respectively, with the considerable removal rate of 0.465 g/m2/d for TN and 0.134 g/m2/d for TP at a hydraulic retention time of 6 days. In additionally, it was found that a lower duckweed density could lead to higher dissolved oxygen in the water and then a higher removal percentage of NH4+-N by nitrobacteria. This study obtains the preferable operation conditions for wastewater treatment and high-protein biomass production in a duckweed-based pilot-scale system, supplying an important reference for further large-scale applications of duckweed.

scholarly journals Behavior of UV Filters, UV Blockers and Pharmaceuticals in High Rate Algal Ponds Treating Urban Wastewater

Water ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2658
Author(s):  
Lucas Vassalle ◽  
Adrià Sunyer-Caldú ◽  
M. Silvia Díaz-Cruz ◽  
Larissa Terumi Arashiro ◽  
Ivet Ferrer ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Environmental Risk ◽  
Cost Effective ◽  
Pilot Scale ◽  
High Rate ◽  
Uv Filters ◽  
Urban Wastewater ◽  
Cost Effective Alternative ◽  
No Elimination ◽  
Influent Wastewater

The present study evaluated the efficiency of a high rate algal pond (HRAP) at pilot scale to remove pharmaceuticals and personal care products (PPCPs) from urban wastewater, including UV-filters and parabens (10), benzotriazoles (4), antibiotics (15), anti-inflammatories (3) and other pharmaceuticals (3). A total of 35 compounds were targeted, of which 21 were detected in the influent wastewater to the HRAP. Removals (RE%) for pharmaceuticals were variable, with efficient eliminations for atenolol (84%) and sulfathiazole (100%), whereas the anti-inflammatories naproxen and ketoprofen were only partially removed <50%. Benzotriazoles showed elimination rates similar to those of conventional WWTPs, with RE% ranging from no elimination to 51% for the UV filter benzophenone-3 (BP3) and 100% for 4-methylbenzilidenecamphor (4MBC). Hazard quotients (HQs) were estimated for those compounds not fully eliminated in the HRAP, as well as the cumulative ecotoxicity in the resulting effluent. The majority of the compounds yielded HQs < 0.1, meaning that no environmental risk would be derived from their discharge. Overall, these results clearly indicate that HRAPs are a reliable, green and cost-effective alternative to intensive wastewater treatment, yielding promising results removing these contaminants.

Nitrous oxide (N2O) emissions during real domestic wastewater treatment in an outdoor pilot-scale high rate algae pond

2019 ◽  
Vol 44 ◽  
pp. 101670 ◽  
Author(s):  
Maxence Plouviez ◽  
Paul Chambonnière ◽  
Andy Shilton ◽  
Michael A. Packer ◽  
Benoit Guieysse
Keyword(s):  
Nitrous Oxide ◽  
Wastewater Treatment ◽  
Domestic Wastewater ◽  
Pilot Scale ◽  
High Rate ◽  
N2o Emissions ◽  
Domestic Wastewater Treatment

Using wastewater and high-rate algal ponds for nutrient removal and the production of bioenergy and biofuels

2013 ◽  
Vol 67 (4) ◽  
pp. 915-924 ◽  
Author(s):  
David Batten ◽  
Tom Beer ◽  
George Freischmidt ◽  
Tim Grant ◽  
Kurt Liffman ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Nutrient Removal ◽  
Large Scale ◽  
Oxygen Demand ◽  
Recent Change ◽  
High Rate ◽  
Coastal Zones ◽  
Nitrogen And Phosphorus ◽  
Treatment Technology ◽  
Algae Biomass

This paper projects a positive outcome for large-scale algal biofuel and energy production when wastewater treatment is the primary goal. Such a view arises partly from a recent change in emphasis in wastewater treatment technology, from simply oxidising the organic matter in the waste (i.e. removing the biological oxygen demand) to removing the nutrients – specifically nitrogen and phosphorus – which are the root cause of eutrophication of inland waterways and coastal zones. A growing need for nutrient removal greatly improves the prospects for using new algal ponds in wastewater treatment, since microalgae are particularly efficient in capturing and removing such nutrients. Using a spreadsheet model, four scenarios combining algae biomass production with the making of biodiesel, biogas and other products were assessed for two of Australia’s largest wastewater treatment plants. The results showed that super critical water reactors and anaerobic digesters could be attractive pathway options, the latter providing significant savings in greenhouse gas emissions. Combining anaerobic digestion with oil extraction and the internal economies derived from cheap land and recycling of water and nutrients on-site could allow algal oil to be produced for less than US$1 per litre.

Oxidation-reduction potential (ORP) regulation of nutrient removal in activated sludge wastewater treatment plants

2002 ◽  
Vol 46 (1-2) ◽  
pp. 35-39 ◽  
Author(s):  
B. Li ◽  
P. Bishop
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nutrient Removal ◽  
Wastewater Treatment Plants ◽  
Pilot Scale ◽  
Redox Status ◽  
Organic Substrate ◽  
Microbial Biodegradation ◽  
Scale Experiment ◽  
One Year

Redox potential (ORP) regulation of nutrient removal in aeration tanks was tested for one year in three activated sludge wastewater treatment plants in Cincinnati, OH. The experiment results show a good relationship between ORP values and nutrient removal. Macro-biodegradation and sorption of substrate by activated sludge can significantly increase wastewater ORP, indicating the improvement of redox status of the bulk liquor. DO higher than 1.0 mg/L is necessary for good biodegradation and the improvement of liquid redox status. ORP values at higher temperatures (Twater=20–26°C) were lower than ORP values at lower temperatures (Twater=14–19°C), caused by the lower oxygen saturation capacity in wastewater and the more rapid oxygen consumption by microorganism under warmer conditions. Nitrification occurred at higher ORP values (380 mV) than did organic substrate oxidation (250mV). This verifies that different metabolic processes dominate in different ORP ranges. The pilot-scale experiment results demonstrate that the wastewater ORP values continued to increase throughout the whole 6-hour cycle when the influent COD was higher than 1,000 mg/L. For influent with low COD (40–120 mg/L), the wastewater ORP values did not increase in the second 3 hours of the cycle, during which time the microbial-biodegradation within the activated sludge floc dominated. High DO concentrations (6–8 mg/L) did not help improve the redox status. In fully-aerated wastewater, oxygen deeply penetrated into the activated sludge flocs, and microorganisms biodegraded the substrates within the flocs. Endogenous metabolism predominated.

Bacterial removal in three pilot-scale wastewater treatment systems for rural areas

1997 ◽  
Vol 35 (11-12) ◽  
pp. 197-200 ◽  
Author(s):  
M. Garcia ◽  
E. Bécares
Keyword(s):  
Wastewater Treatment ◽  
Rural Areas ◽  
Pathogenic Bacteria ◽  
Removal Rate ◽  
Treatment Plant ◽  
Free Water ◽  
Pilot Scale ◽  
High Rate ◽  
Total Coliforms ◽  
Wastewater Treatment Systems

A comparative study on the removal of several pathogenic bacteria and their indicators was carried out at three natural wastewater treatment systems: stabilisation pond, high-rate algal pond and a free-water macrophyte system, retention times being 24, 5 and 3 days respectively. The macrophyte system showed higher removal efficiency for most of the groups, followed by stabilisation pond and high rate algal pond. All systems showed their highest efficiencies in the reduction of total coliforms, ranging from 98.68% for the stabilisation pond to 99.48% for the macrophyte process. Highly significant differences were found between the systems for bifidobacteria, C. perfringens and total coliforms removal. Pathogens and their indicators showed a different behaviour in their daily removal rate depending on the treatment plant.

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