Filters and media used in aquaponic system filtration: A systematic review

Optimization of hydraulic loading rate in aquaponic system with Common carp (Cyprinus carpio) and Mint (Mentha arvensis)

Innovative Technologies for Sustainable Environmental Remediation in Poor and Middle Income Countries

A study on the optimal hydraulic loading rate and plant ratios in recirculation aquaponic system

An experiment was conducted to evaluate the effect of hydraulic loading rate (HLR) on tomato (Solanum Lycopersicum) with pearlspot (Etroplus suratensis) in a recirculating aquaponic system. The experiment consisted of three treatment groups with different HLR of 3 m.day-1 (T1), 6 m.day-1 (T2), and 12 m.day-1 (T3); while the control (C) group had HLR of 3 m.day-1 without plants. Tomato and pearlspot were stocked at 4 plants.m-2 and 0.86 kg.m-3 (142 no.m-3 with an average initial weight of 6.06±0.09 g), respectively. The results indicated that the HLR had profound influence on the growth of both plant and fish. Tomato growth was highest in T1 (1.60±0.04 kg.m-2), followed by T2 (1.35±0.05 kg.m-2) and T3 (1.09±0.069 kg.m-2). Pearlspot growth was highest in T2 (13.57±0.04 g), followed by T1 (13.48±0.04 g), T3 (13.17±0.01 g), and C (13.00±0.28 g). The removal of nitrate (65.71%), phosphate (46.43%), and potassium (62.74%) was highest in T1, followed by T2, T3, and C. Based on the tomato and pearlspot growth as well as the maximum nutrient removal, a HLR of 3.0 m.day-1 can be recommended for tomato and pearlspot production in an aquaponic system.

Nutrient removal from high ammonium swine wastewater in upflow microaerobic biofilm reactor suffered high hydraulic load

Balancing of nutrient uptake by water spinach (Ipomoea aquatica) and mustard green (Brassica juncea) with nutrient production by African catfish (Clarias gariepinus) in scaling aquaponic recirculation system

Removal of nutrients from septic effluent with re-circulated hybrid tidal flow constructed wetland

Retracted.

Aquaponics is a rapidly growing food-production system integrating aquaculture and hydroponic crop production through an energy-intensive water recirculation process. Crop performance and yield in aquaponics are affected by essential and toxic nutrient levels in the root zone, which can be regulated by water flow rate. This study was conducted to examine the effects of hydraulic loading rate (HLR) on water quality and crop growth and yield in recirculating aquaponic systems set at three different loading rates: high (3.3 m3/m2/day; HFR, which is 12 times lower than recommended loading rate), medium (2.2 m3/m2/day; MFR), and low (1.1 m3/m2/day; LFR). Crop species varying in growth rate were examined for their optimal HLR: fast-growing Chinese cabbage (Brassica rapa) and lettuce (Lactuca sativa); medium-growing mustard (Brassica juncea) and chia (Salvia hispanica); and slow-growing basil (Ocimum basilicum) and Swiss chard (Beta vulgaris). Compared to LFR, HFR decreased water and leaf temperatures and total ammonium nitrogen (TAN) but increased dissolved oxygen and pH in aquaponic solution up to one and two weeks after transplant, respectively. HFR increased NO3–N concentration by 50 and 80%, respectively, compared to MFR and LFR, while reducing the exposure duration of roots to ammonia (NH3–N) and its peak concentration through rapid dissipation of the toxic compound. Lower electrical conductivity (EC) in HFR during the last two weeks of production was associated with higher plant nutrient uptake and greater biomass production. The leaf greenness, photosynthetic rate (Pn), and total plant N were significantly higher at HFR than LFR. Fish growth rate, fresh weight, and feed-conversion efficiency were also increased by HFR. The growth of fast-growing crops including total fresh weight, shoot fresh weight, leaf area, and Pn was not different between HFR and MFR, while HLR had less significant effects on the growth and performance (i.e., shoot fresh weight and whole plant photosynthesis) of slow-growing crops. In conclusion, the flow rate is an important component in aquaponic crop production as it affects spatial and temporal water characteristics and subsequently determines the growth and yield of the crops. HLR at 3.3 m3/m2/day was sufficient across the crops allowing better chemical and physical properties of the aquaponic solution for maximum yield and quality. HLR should be maintained at least at 2.2 m3/m2/day for the production of fast-growing crops but can be lowered for slow-growing crops.

Aquaponic systems combine recirculating aquaculture (growing of fish) with hydroponics (growing of plants in water). The fish in the recirculating aquaculture systems provide nutrients for the plants and the plants remove excess nutrients from the water, making these systems more efficient than traditional farming methods in terms of nutrient utilization. Small, recirculating aquaponic systems may provide a more sustainable and cost-effective alternative for securing food supply in both developing and developed nations. Recirculating aquaculture systems tend to be capital-intensive and require significant power to circulate the water in the fish tanks, which helps with the removal of waste and the distribution of oxygen. To reduce capital costs, alternative, culture vessels made from locally available materials were investigated (i.e. square-shaped tanks, and international bulk containers - IBC). These non-standard shaped culture tanks, pose an additional challenge for proper circulation of the water as compared to traditional round tanks. To address the issue of circulation, numerical and experimental data were obtained for rectangular containers. The numerical results were obtained using OpenFoam models of the experimental setup. The experimental data were obtained by measuring flow velocities in an IBC tank using Acoustic Doppler Velocimetry. Currently the experimental data show good repeatability when data are taken for at least five minutes at each position in the tank. The focus of the continuing work is to establish a good agreement between numerical and experimental results. Ultimately the study will contribute to the design of cost-effective recirculating aquaponic fish and plant systems which require lower capital expenditures and achieve energy-efficient circulation of water in the fish culture tanks.

Section 3 - Types of Filter

Discharge from domestic wastewater treatment plant amongst the main sources of nitrogen pollution in the environment. However, to remove nitrogen conventionally in domestic wastewater require high cost and complex chemical treatment method. Vertical flow aerated rock filter emerged as one of attractive alternative wastewater treatment method due to simplicity and compactness of the system. However, the application is yet to be developed in warm climate countries in particular Malaysia. Therefore, this study was conducted to investigate the effect of hydraulic loading rate (HLR) to the performance of a pilot-scale Vertical Flow Aerated Rock Filter (VFARF) in removing nitrogen from domestic wastewater using pilot-scale VFARF systems with steel slag as the filter media. Furthermore, this study has been designed to focus on the effects of two HLRs; 2.72 and 1.04 m 3 /m 3 .day. Influent and effluent of the filter systems were monitored biweekly basis for 11 weeks and analyzed for selected parameters. Results from this study shows that the VFARF with HLR 1.04 m 3 /m 3 .day has performed better in terms of removal ammonium-nitrogen and TKN as the system able to remove 90.4 ± 6.9%, 86.2 ± 10.7%, whilst the VFARF with 2.72 m 3 /m 3 .day remove 87.4 ± 9.9%, 80 ± 11.7%, respectively. From the observation, it can be concluded that nitrogen removal does affect by HLR as the removal in lower HLR system was higher due to high DO level in the VFARF system with 1.04 m 3 /m 3 .day which range from 4.5 to 5.1 mg/L whilst the DO level was slightly lower in the VFARF system with 2.72 m 3 /m 3 .day in the range of 3.7 to 4.5 mg/L.

Nitrification performance of fixed film biofilters using coarse sand, loess bead, or styrofoam beads in biofilter columns 1 meter high and 30cm in diameter were studied at different hydraulic and organic matter loading rates. Synthetic wastewater was supplied to the culture tank in order to maintain desired TAN concentrations in inlet water to biofilters. All the biofilters were conditioned 5 months before start of sampling. TAN and conversion rates increased with an increase in the hydraulic loading rate (HLR). However, the improvement in biofilter performance was not linearly correlated to HLR in styrofoam bead filters. This is mainly due to the characteristics of the styrofoam beads used. TAN conversion rates of sand filters increased with the increase of HLR up to . per day. No increase in the TAN conversion rate was observed at the highest HLR since flooding on the media surface took place. HLR had a significant impact on the TAN conversion rates in loess bead filter up to the highest HLR tested (P per day than those without the addition of organic matter in styrofoam bead filters. The addition of glucose resulted in a reduction of the TAN conversion rate from 540 to 284g per day. No significant difference of TAN conversion rates between the two organic matter loading rates was found (p. per day, a great reduction of TAN conversion rates was observed in sand filters and loess bead filters. Clearly, organic matter can be one of the most Important Impacting factors on nitrification. conversion rates showed a similar trend for TAN. Based on the TAN and nitrite conversion rates, styrofoam beads showed the best performance among the three filter media tested. Also, the low gravity and price of styrofoam beads make the handling easier and more cost-effective for commercial application. The results obtained at the highest organic matter loading rates can be used in the biofilter design in recirculating aquaculture system.

Nutrient treatment of greywater in green wall systems: A critical review of removal mechanisms, performance efficiencies and system design parameters

A basic review of waterflood filtration, this paper covers the history of filtration, theory, different types of filters and types of filter media. Gravity, pressure, diatomaceous earth and cartridge-type filters are described and their operation discussed. Filter media, such as sand, and coal are presented, and drain systems are discussed. Many of the common operating problems are also listed and described. Introduction For the engineer who must design a filter plant, the selection of the proper media, underdrain, etc., can be a bewildering task. Unfortunately, the theory of filtration has not advanced to the point where it can be of significant help. Experience thus becomes the engineers' best hope; however experience does not always assure optimum results, but it at least narrows the field. The following discussion is to provide a description of the materials commonly used in the oil field and the advantages and disadvantages of each and provide guidelines that will aid the engineer in operating the unit that is installed. History of Filtration in the Oil Fields The first two filters for the clarification of water to be used for injection purposes were installed 30 years ago in the Bradford-Allegany fields. These filters were of the pressure type and contained a graded sand and gravel bed. They were soon followed by gravity filters which were constructed of wood, steel or concrete and contained either sand or anthracite coal as the filter media. In 1937 the first pressure-type filter to contain a graded bed of anthracite coal as the filter media was put into service. Theory of Filtration Filtration may be defined as the process of passing a liquid containing suspended material through a suitable medium in such a manner as to effectively remove the suspended solids from the liquid. Basically this is a mechanical action, and the larger suspended particles will not pass through the interstices of the filter media due to their size; however this action alone may not effect complete clarification, since some of the suspended solids are small enough to pass through the filter media. If there is appreciable turbidity in the filter effluent, coagulation may be necessary.' Coagulation, which may be employed in open pits, tanks or even in the line prior to the filter, tends to agglomerate the smaller suspended material and forms floc particles which are large enough to be retained by the filter media. Usually in the coagulation process sufficient retention time is provided to allow the larger and heavier coagulated particles to settle out and to prevent some of the unreacted coagulant passing through the filter and precipitating in the distribution system. For optimum filter operation, the water from the settling basin or tank contains some floc particles. Initially these particles penetrate the filter media through the numerous voids to a depth of from 2 to 4 in, The actual depth of this penetration into the media depends, to a great extent, upon the rate of filtration, the thoroughness of the pretreatment and the effective size of the filter media. As the filtration process is continued additional suspended solids are trapped in this upper portion of the media. This results in the formation of a thin blanket of sludge, commonly called the Schmutzdecke. The Schmutzdecke is a bulky mass of material composed of floc particles and bacteria and contains millions of small capillaries. When the water is properly pretreated and some floc particles are continuously being carried over to the filter, a good Schmutzdecke is formed initially and filtration continues to improve during the filter cycle. Normally it can be expected that with good filter operation all particles larger than 45 microns will be removed, although in many cases effective removal of smaller size particles is obtained. It is apparent that the presence of floc particles in the water entering the filter contributes to more effective filtration. On the other hand, it is seldom desirable for the turbidity of the incoming water to be in excess of 10 ppm. If the amount of floc entering the filters is too large, the length of filter cycle will be substantially reduced. JPT P. 1220ˆ