Biofilter aquaponic system for nutrients removal from fresh market wastewater

Aquaponics is a significant wastewater treatment system which refers to the combination of conventional aquaculture (raising aquatic organism) with hydroponics (cultivating plants in water) in a symbiotic environment. This system has a high ability in removing nutrients compared to conventional methods because it is a natural and environmentally friendly system (aquaponics). The current chapter aimed to review the possible application of aquaponics system to treat fresh market wastewater with the intention to highlight the mechanism of phytoremediation occurs in aquaponic system. The literature revealed that aquaponic system was able to remove nutrients in terms of nitrogen and phosphorus

Investigate the influence of the hydrodynamics on the photobioreactor performance: Effect of configuration and gas distributor

Study the effect of gas sparger on gas holdup, and bubble dynamics such as bubble passage frequency, chord length distribution, and interfacial area in an air-water system in a bubble column PBR. Study the influence of gas sparger on hydrodynamics of PBR using real system. Study the impact of gas sparger for nutrients removal using wastewater as a medium. Lastly, study the synergistic effect and optimization of most influential parameters on CO2 fixation and nutrients removal

Photobioreator technology for carbon capture and nutrients removal

Carbon dioxide concentration in the atmosphere is increasing significantly worldwide. Many are debating the influence of increasing carbon dioxide concentration on global climate, but most scientists agreed that the increasing carbon dioxide concentrations will have a deep effect on the environment. Most of the carbon dioxide results from combustion of fossil fuels to fulfill the increasing demand for energy. Meeting this demand without significantly increasing the Carbon dioxide emissions will require more than the conventional carbon capture and storage techniques. There is growing recognition of microalgae as one of the most efficient biological systems to capture industrial CO2 and produce biomass (bio-fuel) at the same time. Algae also has the potential to remove nutrient from wastewater such as nitrogen and phosphorus. Green algae utilize carbon dioxide in their main building blocks in the photosynthesis process, which means that algal have a high potential for CO2 capture and sequestration. Algae can also produce high value products which can boost the revenues to overcome the relatively expensive microalgae culturing. Algae requires sunlight and CO2 to perform the photosynthesis process, to maximize the energy stored in algae and increase the growth rate of algae a large amount of CO2 is required which is available from the discharge of heavy industries. Algal production does not require a high purity CO2 stream, flue gas containing different CO2 concentrations can be fed directly to the photo-bioreactor which will make the CO2 separation from the flue gas much easier and less expensive. The objectives of the study were (1) evaluate the capability of algae to capture CO2 from gaseous streams at different concentrations [5, 10and 15v/v%] and different temperatures [20, 25, 30◦C], (2) ability of algae to remove nutrient from secondary effluent wastewater under different temperatures [25 and 30◦C], and CO2 concentrations [5% and 10%]. Experiments were carried out in lap-scale and pilot scale set up. Lab-scale results showed that the maximum growth rate, biomass productivity and CO2 bio-fixation rate for Spirulina platensis (SP.PL) were obtained at temperature of 25◦C for culture injected with 10 v/v% CO2. Under these conditions, growth rate, biomass productivity and CO2 bio-fixation rate were determined to be 0.772 d-1, 0.15 g.L-1.d-1 and 0.281 g.L-1.d-1, respectively. These values are higher than the values reported in literature for green algae strains grown under similar conditions. Higher growth rate, biomass productivity and CO2 bio-fixation rate were obtained in the experiments carried out using natural solar light in pilot plant PBR. SP.PL under the same previous conditions (25◦C and 10% CO2 injection) was able to achieve biomass productivity and CO2 biofixation rate of 0.153 g.L-1.d-1 and 0.281 g.L-1.d-1, respectively. Experiments carried out to study the performance of SP.PL in removing nutrients from wastewater showed a typical algae growth rate under both temperatures (25 and 30◦C) and CO2 injection dosage (5 and 10%). The growth of algae in wastewater was observed to have lag phase up to 7 days followed by an exponential growth phase. Decay or stationary phase was not observed under the tested operational conditions. Ammonia removals by SP.PL for experiments performed at 25 ◦C and with CO2 injection of 0, 5 and 10 % were 94.5, 92.4 and 84.5%, Respectively. The % phosphorous removals for the same previous conditions were 94.8, 89.3 and 84.2%, respectively. The results of this study show that microalgae-based wastewater treatment systems can be successfully employed at different temperatures as a successful CO2 capturing technology and post-wastewater treatment proces

Fluoxetine and Nutrients Removal from Aqueous Solutions by Phycoremediation

The tertiary treatment using microalgae offers an attractive alternative to the removal of low but relevant concentrations of pharmaceuticals from domestic wastewaters. The removal of fluoxetine from aqueous solutions by living and non-living (lyophilized) Chlorella vulgaris was assessed. The determination of the pH at the point of zero charge, Fourier transmittance infrared analysis, and scanning electron microscopy were performed to characterize the microalgae biomass. Kinetic and equilibrium experiments were performed. The pseudo-second-order model described the kinetics of fluoxetine. The corresponding kinetic constants indicated that biosorption was faster onto non-living biomass than onto living biomass. The equilibrium results showed that the systems followed the Langmuir isotherm model. The maximum capacity of living microalgae (1.9 ± 0.1 mg·g−1) was slightly higher than the non-living microalgae (1.6 ± 0.2 mg·g−1). Living Chlorella vulgaris, free and immobilized in calcium-alginate, were also used to remove fluoxetine and nutrients (nitrogen and phosphorus) from treated municipal wastewater in a batch system. In both experiments, fluoxetine was completely removed within six days. The total phosphorus (TP) and total nitrogen (TN) removal efficiencies achieved for free and immobilized cells were, null and 65.0 ± 0.1%, and 86.2 ± 0.1% and 81.8 ± 3.1, respectivelyThis research was funded by the Associate Laboratory for Green Chemistry-LAQV, which received financial support from UIDB/50006/2020, UIDP/50006/2020, and LA/P/0008/2020 by the Fundação para a Ciência e a Tecnologia (FCT)/Ministério da Ciência, Tecnologia e En sino Superior (MCTES) through national funds. This research was also funded by the EU and FCT/UEFISCDI/FORMAS, in the frame of the collaborative international consortium REWATER— “Sustainable and safe water management in agriculture: increasing the efficiency of water reuse for crop growth while protecting ecosystems, services and citizens’ welfare” (WaterJPI/0007/2016), which was financed under the ERA-NET Co-fund WaterWorks2015 Call, as an integral part of the 2016 Joint Activities developed by the Water Challenges for a Changing World Joint Program Initiative (Water JPI). The research was funded also by FCT and BiodivRestore Joint Call 2020–2021-European Union’s Horizon 2020 research and innovation program under grant agreement No. 101003777- BiodivRestore-406/DivRestore/0002/2020-BioReset-“Biodiversity restoration and conservation of inland water ecosystems for environmental and human well-being”. A.D.M. Silva would like to thank FCT for her Ph.D. Grant SFRH/BD/138/780/2018. The authors are greatly indebted to all financing sources. The authors are grateful to Materials Centre of the University of Porto (CEMUP), Porto, Portugal, for expert assistance with SEM/EDSinfo:eu-repo/semantics/publishedVersio

Natural pigments from microalgae grown in industrial wastewater

The aim of this study was to investigate the cultivation of Nostoc sp., Arthrospira platensis and Porphyridium purpureum in industrial wastewater to produce phycobiliproteins. Initially, light intensity and growth medium composition were optimized, indicating that light conditions influenced the phycobiliproteins production more than the medium composition. Conditions were then selected, according to biomass growth, nutrients removal and phycobiliproteins production, to cultivate these microalgae in food-industry wastewater. The three species could efficiently remove up to 98%, 94% and 100% of COD, inorganic nitrogen and PO43--P, respectively. Phycocyanin, allophycocyanin and phycoerythrin were successfully extracted from the biomass reaching concentrations up to 103, 57 and 30 mg/g dry weight, respectively. Results highlight the potential use of microalgae for industrial wastewater treatment and related high-value phycobiliproteins recovery

Membrane bio-reactor (MBR) : effect of operating parameters and nutrients removal

University of Technology Sydney. Faculty of Engineering and Information Technology.Membrane bio-reactor is an efficient, cost effective and reliable treatment process to produce high quality water from wastewater. In this study, a number of submerged membrane bio-reactors (SMBRs) experiments were conducted at different organic loading rates (OLRs) and fluxes (ranging from 2.5 - 40 L/m².h and corresponding hydraulic retention time of 10 - 1.5 h) to investigate their influence on organic and nutrient removal and on membrane fouling. A second set of experiment was also carried out with gradual increase of salt concentration in continuous MBR to assess its performances in this particular scenario (which may occur in coastal areas and in certain industries). The operation of MBRs at low HRT resulted in sudden rise of trans membrane pressure (TMP). The sudden development of TMP was minimized by introducing granular activated carbon (GAC) in MBR as suspended medium. The incorporation of GAC reduced TMP or total membrane resistance by 58% and also helped to remove an additional amount of dissolved organic matter. Further, a set of ion exchange adsorption study was conducted for the removal and recovery of the nutrients from the effluent of high rate MBR. The major findings are summarizes below. The increase of OLR, flux and salt concentration resulted in lower removal of organic and nutrients and also caused higher membrane fouling (i.e. increased transmembrane pressure (TMP) development). The removal efficiency of DOC decreased from 93 – 98 % to 45 - 60 % when the OLR increased from between 0.5 – 1.0 to 2.75 – 3.0 kg COD/m³d. Similarly the removal of ammonia decreased from 83–88% to less than 67% when the OLR was increased to 2.0 – 3.0 kg COD/m3d. The increase of flux (i.e. reducing of HRT) also resulted in 30 - 40 % lower removal of organics and nutrients. The removal of organic and nutrient decreased when the salt concentration was increased from 0 to 35 g/L. Based on the operating conditions of this study, the suspended media had less effect on nitrification but had an influence on organic removal. However, changing the operating parameters (such as increase of SRT) may improve nitrification rate. The increase of OLR and salt concentration resulted in higher membrane fouling. Similarly flux and aeration rate also played a major role in membrane fouling reduction. However, the effect of flux on the reduction of membrane fouling was much higher than that caused by aeration rate. A lower flux of 20 L/m² h produced 75 times more water than a higher flux of 40 L/m²h with an aeration rate of 0.6 m³/m² membrane area.h. The reduction of aeration rate from 1.5 to 1.0 m³/m² membrane area.h caused a sudden rise of TMP. The sudden rise of TMP can be minimized by incorporating the medium in suspension in the reactor (to induce surface scouring of the membrane). The incorporation of suspended medium prevented a sudden rise of TMP (total membrane resistance reduced by ~ 58%) by creating an extra shearing effect onto the membrane surface produced by suspended media. It reduced the deposition of particles on the membrane surface by scouring. The addition of GAC also adsorbed some organic matter prior to its entry to the membrane. Nevertheless it is also important to apply a sufficient aeration rate (in our case 1 m³/m² membrane area h) to maintain a good functioning of suspended media in MBR. The aeration helped in scouring and provision of oxygen to microorganisms and maintained the media in suspension. Additionally, the amount and sizes of the suspended medium played major role in fouling reduction. In this study, we found the concentration of suspended media of 2 g/L and GAC size of 300-600 μm was effective in reducing membrane fouling. Therefore a suitable amount and size of suspended medium needed depends on the flux and aeration (or air scour) rate used. The characteristics of organic matter of SMBRs effluent showed that a range of organic matter (such as amino acids, biopolymers, humics and fulvic acids type substances) was removed by the GAC both by scouring and adsorption mechanisms. A detailed organic matter characterization of membrane foulant, soluble microbial product and extracellular polymeric substances showed that bio-polymer together with humic acid and lower molecular neutral and acids were responsible for membrane fouling along with the deposition of floc particle onto the membrane surface. MBR usually removes both organic matter and nitrogen from water. However, the removal of nitrogen and phosphorus using a high rate MBR system is not sufficient. It is equally practical to remove nitrogen and phosphorus by physico-chemical processes as post-treatment such as ion exchange/ adsorption. In this study, different ion exchange materials such as purolite (A520E and A500P), hydrated ferric oxide (HFO) and zirconium (IV) hydroxides were used to remove nitrogen and phosphorus from MBR effluent. They all showed ~ 90% removal of nutrients. The nutrients captured on the ion exchanger were later recovered when the ion-exchange was regenerated

Nutrients Removal Control via an Intermittently Aerated Membrane Bioreactor

Nitrogen is among the main nutrients encouraging the growth of organic matter and algae which cause eutrophication in water bodies. Therefore, its removal from wastewater has become a worldwide emerging concern. In this research, an innovative Membrane Bioreactor (MBR) system named "moving bed membrane bioreactor (MBMBR)" was developed and investigated under intermittently-aerated mode for simultaneous removal of organic carbon and nitrogen. Results indicated that the variation of the intermittently aerated duration did not have an apparent impact on COD and NH4+–N removal rate, yielding the effluent with average COD and NH4+–N removal efficiency of more than 92 and 91% respectively. However, in the intermittently aerated cycle of (continuously aeration/0s mix), (aeration 90s/mix 90s) and (aeration 90s/mix 180s); the average TN removal efficiency was 67.6%, 69.5% and 87.8% respectively. At the same time, their nitrite accumulation rate was 4.5%, 49.1% and 79.4% respectively. These results indicate that the intermittently aerated mode is an efficient way to controlling the nitrification to stop at nitrition; and also the length of anoxic duration is a key factor in improving TN removal

Nutrients Removal Control via an Intermittently Aerated Membrane Bioreactor

Nitrogen is among the main nutrients encouraging the growth of organic matter and algae which cause eutrophication in water bodies. Therefore, its removal from wastewater has become a worldwide emerging concern. In this research, an innovative Membrane Bioreactor (MBR) system named "moving bed membrane bioreactor (MBMBR)" was developed and investigated under intermittently-aerated mode for simultaneous removal of organic carbon and nitrogen. Results indicated that the variation of the intermittently aerated duration did not have an apparent impact on COD and NH4+–N removal rate, yielding the effluent with average COD and NH4+–N removal efficiency of more than 92 and 91% respectively. However, in the intermittently aerated cycle of (continuously aeration/0s mix), (aeration 90s/mix 90s) and (aeration 90s/mix 180s); the average TN removal efficiency was 67.6%, 69.5% and 87.8% respectively. At the same time, their nitrite accumulation rate was 4.5%, 49.1% and 79.4% respectively. These results indicate that the intermittently aerated mode is an efficient way to controlling the nitrification to stop at nitrition; and also the length of anoxic duration is a key factor in improving TN removal

Nutrients Removal Control via an Intermittently Aerated Membrane Bioreactor

Nitrogen is among the main nutrients encouraging the growth of organic matter and algae which cause eutrophication in water bodies. Therefore, its removal from wastewater has become a worldwide emerging concern. In this research, an innovative Membrane Bioreactor (MBR) system named "moving bed membrane bioreactor (MBMBR)" was developed and investigated under intermittently-aerated mode for simultaneous removal of organic carbon and nitrogen. Results indicated that the variation of the intermittently aerated duration did not have an apparent impact on COD and NH4+–N removal rate, yielding the effluent with average COD and NH4+–N removal efficiency of more than 92 and 91% respectively. However, in the intermittently aerated cycle of (continuously aeration/0s mix), (aeration 90s/mix 90s) and (aeration 90s/mix 180s); the average TN removal efficiency was 67.6%, 69.5% and 87.8% respectively. At the same time, their nitrite accumulation rate was 4.5%, 49.1% and 79.4% respectively. These results indicate that the intermittently aerated mode is an efficient way to controlling the nitrification to stop at nitrition; and also the length of anoxic duration is a key factor in improving TN removal

Nutrients Removal Control via an Intermittently Aerated Membrane Bioreactor

Nitrogen is among the main nutrients encouraging the growth of organic matter and algae which cause eutrophication in water bodies. Therefore, its removal from wastewater has become a worldwide emerging concern. In this research, an innovative Membrane Bioreactor (MBR) system named "moving bed membrane bioreactor (MBMBR)" was developed and investigated under intermittently-aerated mode for simultaneous removal of organic carbon and nitrogen. Results indicated that the variation of the intermittently aerated duration did not have an apparent impact on COD and NH4+–N removal rate, yielding the effluent with average COD and NH4+–N removal efficiency of more than 92 and 91% respectively. However, in the intermittently aerated cycle of (continuously aeration/0s mix), (aeration 90s/mix 90s) and (aeration 90s/mix 180s); the average TN removal efficiency was 67.6%, 69.5% and 87.8% respectively. At the same time, their nitrite accumulation rate was 4.5%, 49.1% and 79.4% respectively. These results indicate that the intermittently aerated mode is an efficient way to controlling the nitrification to stop at nitrition; and also the length of anoxic duration is a key factor in improving TN removal