Effect of algal recycling rate on the performance of Pediastrum boryanum dominated wastewater treatment high rate algal pond

2014 ◽  
Vol 70 (8) ◽  
pp. 1299-1306 ◽  
Author(s):  
J. B. K. Park ◽  
R. J. Craggs
Keyword(s):  
Biomass Productivity ◽  
Organic Content ◽  
High Rate ◽  
Recycling Rate ◽  
Total Biomass ◽  
Optimum Level ◽  
Ambient Conditions ◽  
Algal Production ◽  
Algal Concentration ◽  
Pediastrum Boryanum

Recycling a portion of gravity harvested algae promoted the dominance of a rapidly settling colonial alga, Pediastrum boryanum (P. boryanum) and improved both biomass productivity and settleability in High Rate Algal Pond (HRAP) treating domestic wastewater. The effect of algal recycling rate on HRAP performance was investigated using 12 replicate mesocosms (18 L) that were operated semi-continuously under ambient conditions. Three experiments were conducted during different seasons with each experiment lasting up to 36 days. Recycling 10%, 25%, and 50% of the ‘mass’ of daily algal production all increased total biomass concentration in the mesocosms. However, recycling >10% reduced the organic content (volatile suspended solids (VSS)) of the mesocosm biomass from 83% to 68% and did not further increase biomass productivity (based on VSS). This indicates that if a HRAP is operated with a low algal concentration and does not utilise all the available sunlight, algal recycling increases the algal concentration up to an optimum level, resulting in higher algal biomass productivity. Recycling 10% of the daily algal production not only increased biomass productivity by ∼40%, but increased biomass settleability by ∼25%, which was probably a consequence of the ∼30% increase in P. boryanum dominance in the mesocosms compared with controls without recycling.

Impact of soil salinity on growth performance of the plant Syzygium travancoricum Gamble. in their natural habitat - A critically endangered tree species of Southern Western Ghats

2015 ◽  
Vol 22 (4) ◽  
pp. 219-223
Author(s):  
Abdul Hussain ◽  
C. Anilkumar
Keyword(s):  
Soil Salinity ◽  
Natural Habitat ◽  
Critically Endangered ◽  
High Rate ◽  
Optimum Level ◽  
Endangered Tree ◽  
Endangered Tree Species ◽  
Critically Endangered Species ◽  
Nutrients Uptake ◽  
Southern Western Ghats

Increased rate of soil salinity caused changes in macro and micro nutrients uptake, which may lead to decline in photosynthesis capacity and respiration in the plant Syzgium travancoricum Gamble. is a critically endangered species located in damp forest with marshy land, where high rate of salt accumulation has been happening. An optimum level of salinity (0.05 - 0.07) is inevitable for the proper growth and survivability of this species in their natural habitat and also for natural regeneration. A range of reduction in the number of existing plants of this species can be seen in their natural habitat due to the salinity stress.

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.

scholarly journals Consistent drivers of plant biodiversity across managed ecosystems

2016 ◽  
Vol 371 (1694) ◽  
pp. 20150284 ◽  
Author(s):  
Vanessa Minden ◽  
Christoph Scherber ◽  
Miguel A. Cebrián Piqueras ◽  
Juliane Trinogga ◽  
Anastasia Trenkamp ◽  
...  
Keyword(s):  
Species Richness ◽  
Plant Species ◽  
Real World ◽  
Structural Equation ◽  
Structural Equation Models ◽  
Biomass Productivity ◽  
Plant Species Richness ◽  
Ecosystem Functions ◽  
Total Biomass ◽  
Managed Ecosystems

Ecosystems managed for production of biomass are often characterized by low biodiversity because management aims to optimize single ecosystem functions (i.e. yield) involving deliberate selection of species or cultivars. In consequence, considerable differences in observed plant species richness and productivity remain across systems, and the drivers of these differences have remained poorly resolved so far. In addition, it has remained unclear if species richness feeds back on ecosystem functions such as yield in real-world systems. Here, we establish N = 360 experimental plots across a broad range of managed ecosystems in several European countries, and use structural equation models to unravel potential drivers of plant species richness. We hypothesize that the relationships between productivity, total biomass and observed species richness are affected by management intensity, and that these effects differ between habitat types (dry grasslands, grasslands, and wetlands). We found that local management was an important driver of species richness across systems. Management caused system disturbance, resulting in reduced productivity yet enhanced total biomass. Plant species richness was directly and positively driven by management, with consistently negative effects of total biomass. Productivity effects on richness were positive, negative or neutral. Our study shows that management and total biomass drive plant species richness across real-world managed systems.

scholarly journals The objectives and legal instruments of Municipal Waste Management in the Slovak Republic

2020 ◽  
pp. 29-40
Author(s):  
Martin Dufala
Keyword(s):  
European Union ◽  
Waste Management ◽  
Slovak Republic ◽  
Waste Recycling ◽  
Municipal Waste ◽  
High Rate ◽  
Recycling Rate ◽  
The European Union ◽  
Municipal Waste Management ◽  
Per Capita

In particular, two types of data are important for assessing the state of waste management in each Member State of the European Union — first, the amount of the waste generated per capita annually and waste recovery rate, second, the rate of waste disposal in accordance with the waste hierarchy. The latest available statistics on the amount of waste generated per capita are for 2018. While the European Union average is 492 kg of municipal waste produced per capita for 2018, the Slovak Republic’s waste production is slightly less than that, with an average of 414 kg of municipal waste produced per capita for 2018. On the other hand, Denmark with 766 kg of municipal waste produced per capita annually is at the bottom of the European Union ranking. The Czech Republic with 351 kg and Poland with 329 kg of municipal waste produced per capita on the average annually for the same period are in better position than Slovak Republic. Another important data for the evaluation of the state of municipal waste management is the rate of recovery of municipal waste, alternatively — the municipal waste recycling rate. Within this scope, the Slovak Republic performs considerably worse, both regarding the waste management objectives and in comparison with the European Union average, or in comparison with remaining Member States. While the average recycling rate of municipal waste in the European Union was 47.0% in 2018, the Slovak Republic recycled only 36.3% of municipal waste in 2018. The situation within this scope in the Czech Republic/Czechia (34.5%) and Poland (34.3%) were similar. Germany achieved the highest municipal waste recycling rate in 2018, up to 67.3%. Directly related to the rate of the municipal waste recovery is the high rate of waste disposal, especially in the form of landfill, which was in the Slovak Republic in 2018 amounted to 55.0%. Despite the high rate of landfill, we can speak of a reduction in the landfill rate of municipal waste compared to previous years. From the foregoing data of selected indicators of the average recycling rate of municipal waste, it can be deduced that the system of municipal waste management in the Slovak Republic is obviously flawed, in as much as municipal waste management lacks long-term management in accordance with the waste hierarchy. The said deficiency may result either from insufficient legislation pertaining to this area or failure in terms of its enforcement. 

scholarly journals The Cricket (Gryllus assimilis) as an Alternative Food Versus Commercial Concentrate for Tilapia (Oreochromis sp.) in the Nursery Stage

2019 ◽  
Vol 11 (6) ◽  
pp. 97
Author(s):  
Alejandrino Oseguera Alfaro ◽  
Wilfredo Lanza Núñez ◽  
Jhunior Marcia ◽  
Ismael Montero Fernández
Keyword(s):  
Geographical Area ◽  
Alternative Food ◽  
Average Weight ◽  
Total Biomass ◽  
Optimum Level ◽  
Feed Conversion ◽  
Fish Farms ◽  
Protein Nitrogen ◽  
Water Parameters ◽  
Commercial Diet

In this paper, a 32% commercial diet of protein for tilapia fingerlings (Oreochromis sp.) commonly used in fish farms in the country and cricket meal in a mixture with 32% corn flour as a protein was compared alternative food The breeding, raising and fattening unit of crickets (Gryllus assimilis) was implemented for its subsequent sacrifice and transformation into flour and used as a source of protein in the diet, these gained a weight of 0.70 g. To accommodate the fry, plastic tanks with a capacity of 1 m3 were used, the water was sucked by means of an electric pump; with permanent aeration where 15 individuals of red tilapia per m3 were planted with an average weight of 5 g which reached an average weight/fish/day of 26 g, a growth/fish/day of 0.86 g, the total biomass was 340 g, and a feed conversion factor (FCA) of 1.16. According to the Student’s T analysis and a comparison of means, no differences were found, with a correlation of 83.1% between the food supplied and the increase in weight, the water parameters were found at an optimum level. The protein percentage of cricket flour ranges between 15% and 80% depending on the geographical area, those that were used in the local ration have 58.16% of crude protein and 9.32 of protein nitrogen, the two rations in comparison had a protein content of 32%.

scholarly journals Effects of elevated CO<sub>2</sub> and temperature on phytoplankton community biomass, species composition and photosynthesis during an autumn bloom in the Western English Channel

2017 ◽  
Author(s):  
Matthew Keys ◽  
Gavin Tilstone ◽  
Helen S. Findlay ◽  
Claire E. Widdicombe ◽  
Tracy Lawson
Keyword(s):  
Elevated Temperature ◽  
Phytoplankton Community ◽  
Fold Increase ◽  
Elevated Pco2 ◽  
Total Biomass ◽  
Combined Effects ◽  
English Channel ◽  
Ambient Conditions ◽  
Phytoplankton Productivity ◽  
Community Biomass

Abstract. The combined effects of elevated pCO2 and temperature were investigated during an autumn phytoplankton bloom in the Western English Channel (WEC). A full factorial 36-day microcosm experiment was conducted under year 2100 predicted temperature (+4.5 °C) and pCO2 levels (800 μatm). The starting phytoplankton community biomass was 110.2 (±5.7 sd) mg carbon (C) m−3 and was dominated by dinoflagellates (~ 50 %) with smaller contributions from nanophytoplankton (~ 13 %), cryptophytes (~ 11 %)and diatoms (~ 9 %). Over the experimental period total biomass was significantly increased by elevated pCO2 (20-fold increase) and elevated temperature (15-fold increase). In contrast, the combined influence of these two factors had little effect on biomass relative to the ambient control. The phytoplankton community structure shifted from dinoflagellates to nanophytoplankton at the end of the experiment in all treatments. Under elevated pCO2 nanophytoplankton contributed 90% of community biomass and was dominated by Phaeocystis spp., while under elevated temperature nanophytoplankton contributed 85 % of the community biomass and was dominated by smaller nano-flagellates. Under ambient conditions larger nano-flagellates dominated while the smallest nanophytoplankton contribution was observed under combined elevated pCO2 and temperature (~ 40 %). Dinoflagellate biomass declined significantly under the individual influences of elevated pCO2, temperature and ambient conditions. Under the combined effects of elevated pCO2 and temperature, dinoflagellate biomass almost doubled from the starting biomass and there was a 30-fold increase in the harmful algal bloom (HAB) species, Prorocentrum cordatum. Chlorophyll a normalised maximum photosynthetic rates (PBm) increased > 6-fold under elevated pCO2 and > 3-fold under elevated temperature while no effect on PBm was observed when pCO2 and temperature were elevated simultaneously. The results suggest that future increases in temperature and pCO2 do not appear to influence coastal phytoplankton productivity during autumn in the WEC which would have a negative feedback on atmospheric CO2.

Maize relay intercropping with fodder crops for small-scale farmers in central Brazil

2020 ◽  
Vol 56 (4) ◽  
pp. 561-573
Author(s):  
Alpha Bocar Baldé ◽  
Eric Scopel ◽  
François Affholder ◽  
Fernando Antonio Macena Da Silva ◽  
Jacques Wery ◽  
...  
Keyword(s):  
Biomass Productivity ◽  
Pigeon Pea ◽  
Conventional Tillage ◽  
Small Scale ◽  
Total Biomass ◽  
Maize Crop ◽  
Fodder Crop ◽  
Fodder Crops ◽  
Maize Grain ◽  
Relay Intercropping

AbstractRelay intercropping of maize with fodder crops is a promising option for sustainable intensification of dairy small-scale farms in the Cerrado of Brazil. Twenty-six intercropping trials were conducted on farmers’ fields with the following experimental treatments: sole maize crop cropping (MS), maize-Brachiaria intercropping (MB) and maize-pigeon pea intercropping (MP). The trials were managed by the farmers, i.e. choice of conventional tillage (CT) versus no-tillage (NT), sowing dates, fertilization and weed control. Maize grain yield varied strongly across the farmer fields, from 100 to 5900 kg ha−1 in the MS treatment, 500 to 6900 kg ha−1 in MP and 300 to 5500 kg ha−1 in MB. Intercropping did not significantly affect maize grain yields under NT, but yields were reduced under CT in one out of two seasons. Maize yields in the intercropped systems were also higher under NT than CT. Total biomass productivity was significantly higher in the maize-fodder than in the sole maize system. An increased interval between sowing of maize and fodder crop significantly reduced the fodder crop biomass. Relay intercropping, especially in combination with NT, is a promising option if crop calendars and fertilization are properly managed by farmers to reduce interspecific competition between the maize and fodder crop.

Application of Aluminum Nanopowder for Pure Hydrogen Production

2016 ◽  
Vol 712 ◽  
pp. 261-266
Author(s):  
Alexander P. Ilyin ◽  
Liudmila O. Root ◽  
Andrei V. Mostovshchikov
Keyword(s):  
Ultrahigh Molecular Weight Polyethylene ◽  
High Rate ◽  
Coarse Grained ◽  
Pure Hydrogen ◽  
Ambient Conditions ◽  
Aluminum Nanopowder ◽  
Temperature Diffusion ◽  
Ultrahigh Molecular Weight ◽  
Low Efficiency ◽  
High Degree

The problems of hydrogen energetic as well as a method of high pure hydrogen obtaining are presented in the paper. It was suggested to use the reaction of aluminium nanopowder with water, as the reaction proceeds with high rate even at ambient conditions (the rate of hydrogen emission reached 18 ml/(s∙g)) and high degree of conversion (up to 100 %). The unreasonableness of the replacement of aluminium nanopowder to coarse-grained powder in this reaction due to the low efficiency is shown in the article. As a solution for pure hydrogen obtaining, a phenomenon of self-heating of aluminum nanoparticles and the resulting hydrogen, as well as the effect of its high-temperature diffusion through the membrane of ultrahigh molecular weight polyethylene were used.

Physico-Chemical-Biological Treatment of Municipal Wastewater

1991 ◽  
Vol 24 (7) ◽  
pp. 285-292 ◽  
Author(s):  
F. A. El-Gohary ◽  
S. I. Abo-Elela ◽  
S. A. Shehata ◽  
H. M. El-Kamah
Keyword(s):  
Biological Treatment ◽  
Municipal Wastewater ◽  
Sewage Treatment ◽  
Organic Content ◽  
High Rate ◽  
Experimental Investigations ◽  
Oxidation Pond ◽  
Treated Effluent ◽  
Physico Chemical ◽  
Solids Removal

Physico-chemical sewage treatment via coagulation-sedimentation is put in action for suspended solids removal. The effectiveness of this technology concerning the soluble organic content is extremely low. In direct comparison, the use of a biological sand-bed and a high-rate oxidation pond as a tertiary treatment for the chemically treated effluent brought about a substantial increase in efficiency. Experimental investigations performed led to the conclusions that, for the reuse of wastewater for irrigation, chemical treatment is appropriate. For discharge of treated effluents into surface water, combination of the physico-chemical-biological scheme is recommended.

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