Enhancing growth of Chlamydomonas reinhardtii and nutrient removal in diluted primary piggery wastewater by elevated CO2 supply

2017 ◽  
Vol 75 (10) ◽  
pp. 2281-2290 ◽  
Author(s):  
Fan Qi ◽  
Yan Xu ◽  
Yi Yu ◽  
Xiaosheng Liang ◽  
Li Zhang ◽  
...  
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Nutrient Uptake ◽  
Elevated Co2 ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Nutrient Removal ◽  
Co2 Enrichment ◽  
Piggery Wastewater ◽  
Co2 Concentrations ◽  
Feasible Option

The coupling of primary piggery wastewater as a culture medium with elevated CO2 aeration is thought to be an economically feasible option for the cultivation of microalgae. However, little information is available regarding the photosynthetic characteristics of microalgae and nutrient removal from wastewater at different CO2 concentrations. It was found that elevated CO2 aeration provided sustained growth at CO2 concentrations ranging from 5% to 15% and performed best with 5% CO2 aeration in primary piggery wastewater for Chlamydomonas reinhardtii growth. Photosynthesis, respiration, and nutrient uptake (total nitrogen and total phosphorus) were stimulated in response to CO2 enrichment, thus increasing nutrient uptake in primary piggery wastewater, particularly total nitrogen and total phosphorus. A study of carbon-concentrating mechanism-related gene expression revealed that the levels of mRNAs, such as CAH1, LCIB and HLA3, were significantly downregulated. This represents a possible method for the reconciliation of CO2-stimulated growth with mixotrophic cultivation of C. reinhardtii in diluted primary piggery wastewater.

scholarly journals Population dynamics of Cymodocea nodosa under future ocean scenarios.

2018 ◽  
Author(s):  
Amrit K Mishra
Keyword(s):  
Population Dynamics ◽  
Elevated Co2 ◽  
Marine Ecosystem ◽  
Co2 Enrichment ◽  
Cymodocea Nodosa ◽  
Long Term Effects ◽  
Leaf Production ◽  
Co2 Concentrations ◽  
Carbon Dioxide Co2

Rising carbon dioxide (CO2) concentrations in the atmosphere will increase the average pCO2 level in the world oceans, which will have a knock-on effect on the marine ecosystem. Coastal seagrass communities are predicted to benefit from the increase in CO2 levels, but long-term effects of elevated CO2 on seagrass communities are less understood. Population reconstruction techniques were used to investigate the population dynamics of Cymodocea nodosa meadows, exposed to long term elevated CO2 at volcanic seeps off Greece and Italy. Effect of elevated CO2 was noticed on the growth, morphometry, density, biomass and age structure at CO2 seeps than reference sites. Above to below ground biomass ratio of C. nodosa were higher at CO2 seeps. The shoot age and shoot longevity of plants were lower at seeps. The present recruitment (sampled year) of the seagrass were higher than long-term average recruitment of the communities near the seeps. Carbon to nitrogen ratios (%DW) and annual leaf production of C. nodosa were higher in leaves at seeps. This study suggests under long-term CO2 enrichment C. nodosa production increases, but the plant survival rate decreases because of other co-factors such as nutrient availability and trace metal toxicity. Therefore, along with high CO2 other factors must be taken into consideration while predicting effects of future CO2 concentrations.

scholarly journals Assessment of the Nutrient Removal Potential of Floating Native and Exotic Aquatic Macrophytes Cultured in Swine Manure Wastewater

2020 ◽  
Vol 17 (3) ◽  
pp. 1103 ◽  
Author(s):  
Lei Xu ◽  
Siyu Cheng ◽  
Ping Zhuang ◽  
Dongsheng Xie ◽  
Shiyu Li ◽  
...  
Keyword(s):  
Total Nitrogen ◽  
Total Phosphorus ◽  
Aquatic Plants ◽  
Nutrient Removal ◽  
Swine Manure ◽  
Oxygen Demand ◽  
Chl A ◽  
Oxidation Reduction ◽  
Water Restoration ◽  
Restoration Potential

Although eutrophication and biological invasion have caused serious harm to aquatic ecosystems, exotic and even invasive plants have been used extensively in phytoremediation water systems in China. To identify native aquatic plants with excellent water restoration potential, two representative native floating aquatic plants from Guangdong Province, namely Ludwigia adscendens (PL) and Trapa natans (PT), were selected, with Eichhornia crassipes as a control, to study their growth status, adaptability, and nutrient removal potentials in swine manure wastewater. The results demonstrated that the two native plants offered greater advantages than E. crassipes in water restoration. Within 60 days, PL and PT exhibited excellent growth statuses, and their net biomass growth rates were 539.8% and 385.9%, respectively, but the E. crassipes decayed and died with an increasing HRT (hydraulic retention time). The PL and PT could adjust the pH of the wastewater, improve the dissolved oxygen and oxidation-reduction potential, and reduce the electrical conductivity value. The removal rates of NH4+–N, NO3−–N, NO2−–N, total nitrogen, total phosphorus, chemical oxygen demand (COD), and Chl-a in the PL group reached 98.67%, 64.83%, 26.35%, 79.30%, 95.90%, 69.62%, and 92.23%, respectively; those in the PT group reached 99.47%, 95.83%, 85.17%, 83.73%, 88.72%, 75.06%, and 91.55%, respectively. The absorption contribution rates of total nitrogen (TN) and total phosphorus (TP) in the PL group were 40.6% and 43.5%, respectively, while those in the PT group were 36.9% and 34.5%, respectively. The results indicated that L. adscendens and T. natans are both promising aquatic plants for application to the restoration of swine manure wastewater in subtropical areas.

Nutrient Removal Technology in North America and the European Union: A Review

2006 ◽  
Vol 41 (4) ◽  
pp. 449-462 ◽  
Author(s):  
Jan A. Oleszkiewicz ◽  
James L. Barnard
Keyword(s):  
European Union ◽  
North America ◽  
Activated Sludge ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Nutrient Removal ◽  
Phosphorus Removal ◽  
Biological Nutrient Removal ◽  
The European Union ◽  
The Impact

Abstract The European Union (EU) has implemented effluent (emission) standards since 1991, while North America practices a riskbased, imission approach. Progressing eutrophication and large fees for discharged loads push EU countries toward more stringent effluent concentrations, below total nitrogen (TN) levels of 10 mg/L and total phosphorus (TP) levels of 1 mg/L. In North America, the limit of treatment technology (LOT) concept has been defined as the lowest economically achievable effluent quality, which for TN is <1.5 to 3 mg/L and TP is <0.07 mg/L. These limits are becoming targets in fragile ecoregions in North America and drive the technology solutions towards a combination of advanced biological nutrient removal process trains, followed by chemical polishing and solids separation by granular or cloth filters or membranes. In Western Canada one-biomass biological nutrient removal processes are used, such as Westbank or Step-feed, often followed by filtration to achieve low effluent total phosphorus levels. Eastern Canada has a less stringent approach to nitrogen control and practices chemical phosphorus removal. Requirement for total nitrogen removal and rising costs of phosphorus precipitation drive designers towards advanced one-biomass processes and full utilization of carbon (for denitrification and phosphorus removal) available in raw wastewater and primary sludge. New processes are developed to take advantage of carbon available in waste activated sludge or even in the recycled activated sludge. Sludge treatment return streams have high nutrient loads and novel processes are introduced for their treatment, some utilizing generated nitrifier biomass for bio-augmentation of the main stream nitrification process. The impact of sludge processing on the liquid train and vice versa is now fully embedded in the design process.

Biological nutrient removal at a very low-loaded activated sludge plant with high biomass concentrations

1998 ◽  
Vol 38 (1) ◽  
pp. 63-70 ◽  
Author(s):  
H. J. Kiuru ◽  
J. A. Rautiainen
Keyword(s):  
Activated Sludge ◽  
Total Nitrogen ◽  
Total Phosphorus ◽  
Nitrogen Removal ◽  
Nutrient Removal ◽  
Municipal Wastewater ◽  
Treated Wastewater ◽  
Biological Nutrient Removal ◽  
Activated Sludge Process ◽  
Biological Phosphorus

The Laboratory of Environmental Engineering at the Helsinki University of Technology (HUT) carried out in 1991-1995 two successive full-scale research and development projects at the Pihlajaniemi WWTP of Savonlinna concerning biological nutrient removal from municipal wastewater. The projects have resulted in two reports in Finnish with quite large English summaries. This WWTP was constructed originally (1978) as a conventional low-loaded activated sludge plant with the simultaneous precipitation of phosphorus. It was dimensioned for a sludge concentration of 3.5 kgMLSS/m3 in the aeration tanks. Six years later (1984) the plant was fitted with a tertiary stage of flotation filters in order to improve the removal of suspended solids and phosphorus. Nitrification was introduced to the activated sludge process of the plant in 1987. It could be done without any extension by using the sludge concentrations of 6-10 kgMLSS/m3 in the aeration tanks. In that way, this activated sludge process was converted into a very low-loaded one. The process became able to nitrify totally in the circumstances in which the wastewater temperature varies at the range of 4-20°C. The actual hydraulic as well as the BOD7-load of the plant are about 40% of the original dimensioned ones. This activated sludge process of the Pihlajaniemi WWTP was modified in 1991-1993 for nitrogen removal and then in 1994-1995 for both biological phosphorus and nitrogen removal Denitrification was introduced to the process and the simultaneous precipitation of phosphorus in that was replaced by biological phosphorus removal still without any extension of the activated sludge process. The plant has now been operated over four years with biological nutrient removal exploiting the organic carbon compounds of the wastewater. A very little addition of some precipitant is used to improve the biological removal of phosphorus. The chemical and energy cost of the plant has been reduced by some 50% due to the introduction of biological nutrient removal. The BOD7-value of the treated wastewater is mainly less than 3 mg/l (always less than 5 mg/l). The content of total phosphorus in the treated wastewater is usually less than 0.3 mg/l (always less than 0.5 mg/l). The content of total nitrogen in the treated wastewater is mainly 8-12 mg/l. Reductions for BOD7 and total phosphorus over 95% as well as that for total nitrogen about 70% are achieved.

Seasonal nutrient uptake of plant biomass in a constructed wetland treating piggery wastewater effluent

2013 ◽  
Vol 67 (6) ◽  
pp. 1317-1323 ◽  
Author(s):  
S. Y. Lee ◽  
M. C. Maniquiz ◽  
J. Y. Choi ◽  
S. M. Jeong ◽  
L. H. Kim
Keyword(s):  
Nutrient Uptake ◽  
Constructed Wetland ◽  
Nutrient Removal ◽  
Plant Biomass ◽  
Treatment Plant ◽  
Nutrient Content ◽  
Surface Flow ◽  
Temperate Climate ◽  
Piggery Wastewater ◽  
Concentration Changes

The surface-flow constructed wetland (CW) located in Nonsan City, South Korea, and constructed as the final stage of a piggery wastewater treatment plant that aims to treat high nutrient content effluent during dry days and stormwater runoff during wet days was monitored from October 2008 to November 2011. This research investigated the seasonal nutrient uptake of plant biomass in the CW and nutrient concentration changes in each treatment region under monsoon and temperate climate conditions. Results showed that the mean total nitrogen removal during summer (June to August) was higher by 13% than in spring (March to May), while total phosphorus removal was higher by 22% in fall (September to November) than in winter (December to February). All plants in the CW reached their maximum biomass coverage and weight in summer and minimum growth in winter. The highest N and P content in plants occurred in September with 583.2 g/m2 and August with 62.0 g/m2, respectively. Based on the results, it is recommended that the harvesting of plants should be conducted during the time of the peak nutrient uptake and before the plants release the nutrient content back to the CW. The dependence of nutrient removal efficiency on plants is not so significant. In order to increase the nutrient removal rate by plant uptake, it is suggested that the treatment regions in the CW be covered by plants.

The effect of elevated CO2 on autotrophic picoplankton abundance and production in a eutrophic lake (Lake Taihu, China)

2016 ◽  
Vol 67 (3) ◽  
pp. 319 ◽  
Author(s):  
Shengnan Li ◽  
Jian Zhou ◽  
Lijun Wei ◽  
Fanxiang Kong ◽  
Xiaoli Shi
Keyword(s):  
Primary Production ◽  
Elevated Co2 ◽  
Lake Taihu ◽  
Co2 Enrichment ◽  
Eutrophic Lake ◽  
Trophic Levels ◽  
Autotrophic Picoplankton ◽  
Co2 Concentrations ◽  
Four Seasons ◽  
In Situ Experiments

The effects of elevated CO2 concentrations on the community structure and primary production of the autotrophic picoplankton of a eutrophic lake were studied in Lake Taihu, China. We conducted in situ experiments with three CO2 concentrations (270, 380 and 750ppm) over four seasons during 2012 and 2013. Our results showed that phycocyanin-rich picocyanobacteria were dominant in winter and that photosynthetic picoeukaryotes were prevalent during the other three seasons. CO2 elevation could significantly increase the abundance of photosynthetic picoeukaryotes in all seasons except winter, but did not have any influence on picocyanobacterial abundance. CO2 enrichment caused an increase in the primary production of the picoplankton community in most seasons, and significant differences were observed among the treatments in summer and winter. In addition, the contribution of picoplankton to total primary production significantly increased under higher CO2 concentrations in winter. The increase in the abundance of photosynthetic picoeukaryotes and the primary production of picoplankton under high CO2 concentrations may reduce the transfer of matter and energy to higher trophic levels and increase the importance of the microbial food web.

Use of the bleomycin resistance gene to generate tagged insertional mutants of Chlamydomonas reinhardtii that require elevated CO2 for optimal growth

2002 ◽  
Vol 29 (3) ◽  
pp. 231 ◽  
Author(s):  
Sergio L. Colombo ◽  
Steve V. Pollock ◽  
Karla A. Eger ◽  
Ashley C. Godfrey ◽  
James E. Adams ◽  
...  
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Elevated Co2 ◽  
Insertional Mutagenesis ◽  
Optimal Growth ◽  
Inverse Pcr ◽  
Transformation Protocol ◽  
Low Co2 ◽  
Co2 Concentrations ◽  
Polymerase Chain ◽  
Tail Pcr

Chlamydomonas reinhardtii Dangeard possesses a CO2 concentrating mechanism (CCM) that enables it to grow at very low CO2 concentrations. In previous studies, insertional mutagenesis was successfully used to identify genes required for growth at low CO2 in C. reinhardtii. These earlier studies used the C. reinhardtii genes, Nit1 and Arg7 to complement nit1– or arg7– strains, thereby randomly inserting a second copy of Nit1 or Arg7 into the genome. Because these genes are already present in the C. reinhardtii genome, it was often difficult to identify the location of the inserted DNA and the gene disrupted by the insertion. We have developed a transformation protocol using the BleR gene, which confers resistance to the antibiotic Zeocin. The insertion of this gene allows one to use a variety of existing polymerase chain reaction (PCR) methodologies to identify the disrupted gene. In this study the D66 strain (nit2–, cw15, mt+) was transformed by electroporation using a plasmid containing the BleR gene. Primary transformants (42 000) were obtained after growth in the dark on acetate plus Zeocin medium. Colonies were then tested for their ability to grow photosynthetically on elevated CO2 or low levels of CO2 (100 ppm). About 120 mutants were identified which grew on elevated CO2 but were unable to grow well at low CO2 concentrations. About 50% of these mutants had low affinities for inorganic carbon as assessed by K0.5(CO2), indicating a potential defect in the CCM. The location of the inserted DNA is being determined using inverse PCR (iPCR) and thermal asymmetric interlaced (TAIL) PCR. Using these methods, one can rapidly locate the inserted DNA in the genome and identify the gene that has been disrupted by the insertion.

Achievement of Biological Nutrient Removal in Full-Scale Rotating Biological Contactor Watsewater Treatment Plant

1992 ◽  
Vol 26 (5-6) ◽  
pp. 1115-1124 ◽  
Author(s):  
K. E. Neu
Keyword(s):  
Total Nitrogen ◽  
Total Phosphorus ◽  
Nutrient Removal ◽  
Treatment Plant ◽  
Biological Nutrient Removal ◽  
Secondary Effluent ◽  
Rotating Biological Contactor ◽  
Design Load ◽  
Hydraulic Design ◽  
Demonstration Site

A Central Wisconsin municipal treatment plant (WWTP) with a significant industrial contribution and seven (7) years of Rotating Biological Contactor (RBC) operation was the demonstration site for process modifications which provided significant biological nutrient removal (BNR). The study was conducted June-October, 1990. The plant was near 70% of hydraulic design load and averaged 90% of organic design load, with numerous excursions above organic design load. The BOD:P ratio was above 20:1, and the BOD:TKN ratio was above 10:1. Process modifications resulted in total phosphorus and total nitrogen reductions of 60-90% without chemical addition. Other benefits realized include increased clarity of the secondary effluent and an approximate 50% reduction of RBC shaft biomass weight.

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