Conventional Ponds Research Articles

Methane and nitrous oxide emissions in the rice-shrimp rotation system of the Vietnamese Mekong Delta

Rice-shrimp rotation systems are one of the widespread farming practices in the Vietnamese Mekong Delta coastal areas. However, greenhouse gas (GHG) emissions in the system have remained unclear. This study aimed to examine methane (CH4) and nitrous oxide (N2O) emissions from the system, including (i) land-based versus high-density polyethylene-lined (HDPE) nursery ponds and (ii) conventional versus improved grow-out ponds inoculated with effective microorganisms (EM) bioproducts. The results showed that CH4 flux in land-based and HDPE-lined nursery ponds were 1.04 and 0.25 mgCH4 m−2 h−1, respectively, while the N2O flux was 8.37 and 6.62 μgN2O m−2 h−1, respectively. Global warming potential (GWP) from land-based nursery ponds (18.3 g CO2eq m−2) was approximately 3 folds higher than that of the HDPE-lined nursery pond (6.1 g CO2eq m−2). Similarly, the mean CH4 and N2O fluxes were 15.84 mg CH4 m−2 h−1 and 7.17 μg N2O m−2 h−1 for the conventional ponds, and 10.51 mg CH4 m−2 h−1 and 7.72 μg N2O m−2 h−1 for the improved grow-out ponds. Conventional practices (2388 g CO2eq m−2) had a higher 1.5-fold GWP compared to the improved grow-out pond (1635 g CO2eq m−2). The continuation of the land-based nursery pond and conventional aquacultural farming practices increase CH4 emission and GWP, while applying HDPE-lined nursery ponds combined with improved grow-out ponds could be a promising approach for reducing GHG emissions in rice-shrimp rotation systems. This study recommends further works in the rice-shrimp rotation systems, including (i) an examination of the effects of remaining rice stubbles in the platform on the availability of TOC levels and GHG emissions and (ii) ameliorating dissolved oxygen (DO) concentration on the effectiveness of GHG emission reduction.

Combining nursery closed-system and pond grow-out common carp (Cyprinus carpio) production is a profitable business in Hungary

Extensive, large-scale long-term pond fish production has several challenges and high economic risks, such as continuous bird predation. Moreover, common carp (Cyprinus carpio) production costs are relatively high using this production strategy. To reduce risks and improve production safety and efficiency, European common carp farmers are challenged to shorten the classic 3-year production cycle. This study aimed to comprehensively analyze the main farm parameters, production efficiency, cost and revenue of a production strategy based on combining hatchery/nursery closed-system, a second phase of the nursery in ponds and a final phase of pond grow-out of common carp. A deterministic economic model was used. Combined production has a lower fish loss by bird predation, a shorter production cycle, a better feed conversion ratio than conventional pond fish production, and a similar yield at a cost of approximately 2.02 USD/kg. This value are higher than those assumed in the conventional extensive 3-year common carp, completely pond-based production strategy. However, the current assets turnover ratio is much lower in the latter case. The yearly average net revenue can increase by implementing a more intensive combined production strategy. The combined strategy can improve security and predictability of production while reducing the pond area used for grow-out of extensive common carp farm.

Three-dimensional ecological breeding mode and key technology of fish-frog symbiosis

This paper introduces the mode and key technology of fish-frog symbiosis. Pond fish-frog aquaculture technology is on the basis of conventional pond fish, through the pond, the implementation of bullfrog without land farming, pond fish-frog symbiotic system, realize the pond fish-frog stereo culture, the method has covers an area of less, low cost, enemy, breeding density, bullfrog, fast growth, easy to manage, high comprehensive benefit advantages.

Short Communication: Comparison of the water environment aspects and production of Nile tilapia (Oreochromis niloticus) between biofloc and conventional aquaculture systems in tropical dryland region

Abstract. Halla PTHB, Lalel, H, Santoso P. 2023. Short Communication: Comparison of the water environment aspects and production of Nile tilapia (Oreochromis niloticus) between biofloc and conventional aquaculture systems in tropical dryland region. Intl J Trop Drylands 7: 12-15. The study aimed to compare the water quality of two aquaculture systems (i.e., conventional system and biofloc technology system) used to cultivate Nile tilapia (Oreochromis niloticus Linnaeus, 1758) in tropical dry land areas. This study used a survey method using seven samples for each aquaculture system. The results of the Kruskal-Wallis test showed that there was a significant difference (P<0.05) in the content of ammonia (NH3) between the two aquaculture systems, while the content of nitrate (NO3), phosphate (PO4), dissolved oxygen (DO) and pH was not significantly different (P>0.05). Although the value of ammonia (NH3) in the biofloc aquaculture system is higher than in the conventional aquaculture system, it is still below the quality standard of the aquatic environment. Conversely, the specific growth rate (SGR), relative growth rate (RGR), survival rate (SR), and production of fish between the two aquaculture systems showed significant differences (P<0.05). Where the value of SGR, RGR, and survival rate in conventional ponds is higher than that of biofloc ponds, on the contrary, the value of fish production in biofloc ponds is higher than in conventional ponds.

Pond-in-Pond's anaerobic pit performance over conventional anaerobic ponds – A computational fluid dynamics comparison

Waste stabilization ponds (WSP) are recommended to treat wastewater in small communities. However, due to lack of pond hydraulics knowledge and uncertainties in conventional pond designs, a novel design, the Pond-in-Pond (PIP), was proposed. This design combines an anaerobic pit surrounded by berms into an integrated aerobic pond. Although this design promotes a more reliable operation, the unknown factor is the most appropriate configuration. Thus, to improve the anaerobic pit's design, a series of computational fluid dynamics (CFD) simulations were evaluated. In total, 13 configurations were compared, consisting of three different length-to-width ratios (LWR), 1:3, 1:1, and 3:1. Each LWR was simulated with the outflow exiting the pit through 1, 2, 3, or 4 sides; and, a conventional anaerobic pond with a 3:1 LWR was simulated for reference. The assessment was based on 1) the hydrodynamic velocity profile; 2) a computational tracer test using an Eulerian model to identify the short circuit index, hydraulic retention time and hydraulic efficiency; and 3) the solids' retention capacity in the critical path using Helminths eggs as a reference. The CFD simulations showed the 1:1 LWR (square pit) performed better overall when compared to the 1:3 and 3:1 LWR, and much better than the anaerobic pond. The square pit presented lower velocities, larger hydraulic efficiency, and higher solids' retention capacity, settling particles as small as 50 μm, such as Hookworms. Despite the velocity profiles presented statistically significant differences in the number of sides outflowing, the tracer test demonstrated that the differences were negligible.

Regulatory mechanisms of responsible aquaculture and sustainable development of ecotourism in territorial communities


 
 
 The article analyzes the current state of aquaculture production and recreation in Ukraine, industry problems, the potential and possible ways of situation improvement. It examines tools for developing aquaculture production based on the integration with ecotourism. One has developed a scheme of the interaction between industries and other economic entities in Ukraine. The goal of the article is a comprehensive analysis of the development of responsible aquaculture combined with the ecotourism growth, encouraging the improvement of Ukraine’s economic, tourist and natural potential, sustainable development and economic growth along with the application of resource-saving technologies. One has concluded that the existing synergetic effect has a positive nature and allows not only creating competitive products for Ukrainian consumers but also entering the global market, involving users of recreational services in Ukraine, which substantially increases the potential of this region. The article analyzes the current state of ecotourism in Ukraine, provides recommendations for solving existing problems and increasing the investment flow in the industry by enhancing the demand for ecotourism products, which will positively affect macroeconomic indicators and the national reputation. It is proven that the responsibility for the regional ecological state and control over local enterprise activities should be delegated to local communities because of their susceptibility to changes and rapid response in order to create social systems of environment quality control. One has developed models of dependence of ecotourism development on investments in recreation facilities where the quantity and quality of services will significantly grow, which can become competitive on both internal and external markets and have unique offers not only by applying natural resources but also by providing technological and complex services. It is proven that the use of innovative technologies based on the automation of the aquaculture production process will enhance financial results and decrease external negative effects. Besides, it is more eco-friendly than conventional pond production, but it is capital-intensive and requires investment generation.
 
 

Budidaya Ikan Gurami (Ospheronemus Gouramy) dalam Kolam Bundar pada Kelompok Pemuda Sabilulungan di Sindangkasih Ciamis

This activity aims to improve the knowledge and skills of gourami cultivators in Sindangkasih Village, Sindangkasih District, Ciamis Regency, and to understand the benefits of circular ponds as technology in gourami cultivation to increase the quality and quantity of gourami production. The method of carrying out activities through several stages, namely: Preparation & coordination; Implementation; Monitoring and evaluation. The implementation stage begins by providing counselling regarding the cultivation of gourami in circular ponds, followed by the provision of circular ponds as another option for cultivation so that the cultivators do not experience many losses. As a result of the activity, the cultivators switched to circular ponds. Hence, water quality is more controlled, stocking density, more efficient and effective feeding, there are no dead spots in circular ponds so that fish is always moving. Dirt is not concentrated in one point and, pests can be tackled faster because water is controlled, and pests are quickly controlled, the mortality rate is low. As a result, the maximum yield of gourami fish is within four months. The circular ponds are different from conventional ponds, where water conditions are not optimally controlled so that pests cannot be predicted and are slow in pest management so that the mortality rate is high.

The Oriented Spray Cooling System for Heat Rejection and Evaporation

Abstract Spray ponds offer significant advantages over mechanical draft cooling towers (MDCTs) including superior simplicity and operability, lower preferred power requirements, and lower capital and maintenance costs. Unlike a conventional spray pond in which spray nozzles are arranged in a flat bed and water is sprayed upward, the oriented spray cooling system (OSCS) is an evolutionary spray pond design in which nozzles are mounted on spray trees arranged in a circle and are tilted at an angle oriented toward the center of the circle. As a result, each nozzle is exposed to essentially ambient air as water droplets drag air into the spray region while the warm air concentrated in the center of the circle rises. Both of these effects work together to increase air flow through the spray region. Increased air flow reduces the local wet-bulb temperature of the air in the spray pattern, promoting heat transfer and more efficient cooling. The authors have developed analytical models to predict the thermal performance of the OSCS that are based on classical heat and mass transfer and kinetic vector relationships for spherical water droplets that rely only on generic experimental thermal performance data. Therefore, the model is not limited in application with regard to spray pressure or nozzle spacing or orientation and is not limited by droplet size considerations. This paper describes specific details such as nozzle type, orientation, and drop spectrum and details on the analytical model never before published that are used to predict the OSCS performance. The paper compares the predicted performance of the OSCS with the rigorous full-scale field test results that were measured in compliance with Nuclear Regulatory Commission requirements at the Columbia Generating Station where the ultimate heat sink (UHS) is two OSCS.

Experimental Investigation on a Novel Composite Salt Gradient Solar Pond With an East–West Side Reflector

Abstract A salt gradient solar pond (SGSP) acts as an eco-friendly and cost-efficient device for storing thermal energy storage. It is crucial to enrich the efficiency of the SGSP to boost its thermal energy storage. It can be efficaciously achieved with the application of salt mixtures, reflectors, and by the usage of a glazed layer. This current study investigates the hexagonal composite salinity gradient solar pond (HCSGSP) augmented with a dual inclined reflector and a triple-layer transparent cover. A micro-solar pond having a hexagonal cross section was fabricated and experimented at Coimbatore, India, having a datum and surface area of 1 m and 0.679 m2, respectively. The novel usage of composite salt (sodium chloride 30%, magnesium chloride 10%, and potassium chloride 60%) led to the enhancement of the daily average temperature of pond. The pond’s upper portion was packed with a triple-layer glazed cover which shows an uplift of thermal energy and the pond is provided with inclined reflectors made of plywood fixed with mirrors on the east–west direction. The purpose of the mirrors is to increase the solar radiation intensity during the diurnal period and also it acts as an insulator which minimizes the heat losses during the nocturnal period. Energy balance numerical equations were formulated for all layers in the pond and temperature variation was determined mathematically and experimentally. The maximum thermal efficiencies of the top convective, middle non-convective, and bottom convective layers of reformed solar pond were measured to be 23.44%, 30.68%, and 35.63%, respectively, whereas they were 1.32%, 12.32%, and 23.44%, respectively, in the case of conventional pond. Furthermore, the research provides insight into the impact of shading owing to sidewalls, which has a significant impact on the incident solar radiation and storage of thermal energy in the novel solar pool.

Toward ecological intensification through the co-production of the floating macrophyte Azolla filiculoides and the giant gourami Osphronemus goramy Lacepède (1801) in Indonesian ponds

ABSTRACT The feasibility of the co-culture production of giant gourami Osphronemus goramy, an omnivorous with a herbivorous tendency fish, with high economic and patrimonial value in Indonesia, and floating macrophyte Azolla filiculoides was tested. A three months trial was carried out in an Indonesian small-scale fish farm from November 2017 to February 2018. Four earthen ponds (from 353 to 482 m2) were used. Two ponds were managed as conventional monoculture aquaculture; in the two others, 20% of the pond’s surface was dedicated to the production of A. filiculoides. The objective of this co-production was to replace partially the commercial pellets with fresh, unprocessed Azolla. All ponds were fertilized with chicken manure and stocked with juveniles of giant gourami (24–34 g) bought in the local live fish market at a density of 6 individuals per m2 under both management schemes. Production of Azolla was discontinuous, covering only 40 days over 90 days of the production cycle of Giant gourami. Azollawas harvested every three days producing 571 ± 359 g m−2 (mean ± SD) of biomass. This discontinuity might be attributed to insufficient phosphorous (P) fertilization and predation by other fish, aquatic snails, and insect larvae. In the co-cultured ponds, a total of 15% of commercial pellets were spared by their replacement with fresh Azolla. The specific growth rate (SGR) and the fish biomass gain were similar for both systems. Azolla did not influence water quality. Both production systems were negative economic net-benefice (−17% for conventional ponds and −4% for co-cultured ponds), mainly because of high costs for seeds and sub-optimal feed performance. We demonstrated that the co-production of A. filiculoides did not generate any significant extra cost. We discussed the benefits of ecological intensification with macrophytes in semi-intensive production systems in the tropics.

Boosting fish production in Cameroon: Incorporated fish-rice farming versus earthen pond fish culture in Buea, Mount Cameroon region

Wetland incorporated fish-rice farming (FRF) is a possible solution to the problem of high costs of fish feeds in aquaculture in Cameroon. For 12 weeks, at the University of the Buea (UB) the growth of the fish, Clarias gariepinus in concurrent culture with rice (Oryza sativa, L.) in two rice plots (rice plot 1 and rice plot 2stocking sites) in the University of Buea wetland and in two earthen ponds (fish pond 1 and fish pond 2stocking sites) fed compounded diet at 5% body weight was investigated. Physico-chemical water quality parameters of all the fish culture sites were monitored. Mean fish weight gain was significantly higher (P<0.01) in the wetland rice plots (329.21±44.35g) than in the two earthen ponds (30.01±2.84g). Apart from low mean dissolved oxygen values in the rice plot 1 (3.14±1.19 mg/L) and rice plot 2 (2.18±0.23 mg/L), mean values for physico-chemical water quality parameters were within recommended ranges for C. gariepinus growth in all the four culture sites. This FRF experiment proved a better practice in fish growth than the conventional earthen pond culture in Buea, Cameroon. Its adoption by local fish farmers is recommended.
 Keywords: Wetland integrated fish-rice farming, C gariepinus, earthen pond culture, and fishpond.

ANALISIS REDUKSI POTENSI GAS METANA (CH4) PADA PENGOLAHAN LIMBAH CAIR PABRIK KELAPA SAWIT DENGAN METODE PENGOLAHAN MELALUI BIODIGESTER DAN KOLAM KONVENSIONAL

Research on the analysis of the reduction of the potential of methane gas (CH4) in the processing of palm oil mill effluent with the method of processing through Biodigester and Conventional ponds. Palm oil mill waste management system PT. The Indo Palm Fertile Core which reduces CH4 by splitting the effluent out of the inlet is divided into 2 lines, each pathway of the system aims to reduce methane gas (CH4) that comes from the degradation of organic matter present in the liquid waste. Sample analysis was taken from 6 palm oil mill waste processing ponds owned by PT. Inti Indosawit Subur Pelalawan. In this study the authors calculated repetition of sampling conducted using the Slovin technique. The measured parameters of wastewater are Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), pH and temperature in each pond that affects the formation of methane gas and carbon dioxide. Analysis of methane gas is determined in 1 way namely theoretically using equations and using the Biogas 5,000 Gas Analyzer tool. Calculation of methane gas potential (CH4) is carried out to find out how much the potential of methane gas (CH4) in each WWTP pond. From the calculation of the potential emissions of methane gas (CH4) it will be known how much reduction in methane gas (CH4) in the treatment of liquid waste in PKS PT. Inti Indosawit Subur Pelalawan Regency. Results of COD anasis and methane gas potential in biodigesters The average value of COD loading on Biodigester per day in September at the time of sampling was 24,884 kg / day. Potential emissions of methane captured in the Biodigester is 7,838.46 Nm3 / Day. The percentage of potential methane emissions in the Biodigester per day is 31.5%. Whereas the highest methane gas pool was found in pond 3, which is 6.4 Nm3 / day, which was calculated theoretically with a percentage of methane gas emissions of 0.011%. However, if measured using a tool, the percentage of potential methane gas in a 3 COD pool of 58,112 mg / L is 0% at a temperature of 35 ° C and a pH of 8.38. The highest methane gas emissions occur in pond 3 during the daytime with a value of 6.4 Nm3 / Day on the first day, 6.95 Nm3 / Day on the second day, 6.41 Nm3 / Day on the third day and 6.67 Nm3 / Day on the fourth day, the potential emissions of the biodigester have been calculated by the company. The potential of methane emissions captured in Biodigester is 7,838.46 Nm3 / Day with the percentage of potential methane emissions in Biodigester an average of 31.5% per day. The highest value of methane gas emissions during the 4 days of the study was 6.95 Nm3 / day on the second day taken at noon with a pool temperature of 35 ͦ C.

Ecotoxicological assessment of palm oil mill effluent final discharge by zebrafish (Danio rerio) embryonic assay.

Most palm oil mills adopted conventional ponding system, including anaerobic, aerobic, facultative and algae ponds, for the treatment of palm oil mill effluent (POME). Only a few mills installed a bio-polishing plant to treat POME further before its final discharge. The present study aims to determine the quality and toxicity levels of POME final discharge from three different mills by using conventional chemical analyses and fish (Danio rerio) embryo toxicity (FET) test. The effluent derived from mill A which installed with a bio-polishing plant had lower values of BOD, COD and TSS at 45mg/L, 104mg/L, and 27mg/L, respectively. Only mill A nearly met the industrial effluent discharge standard for BOD. In FET test, effluent from mill A recorded low lethality and most of the embryos were malformed after hatching (half-maximal effective concentration (EC50)=20%). The highest toxicity was observed from the effluent of mill B and all embryos were coagulated after 24h in samples greater than 75% of effluent (38% of half-maximal lethal concentration (LC50) at 96h). The embryos in the effluent from mill C recorded high mortality after hatching, and the survivors were malformed after 96h exposure (LC50=26%). Elemental analysis of POME final discharge samples showed Cu, Zn, and Fe concentrations were in the range of 0.10-0.32mg/L, 0.01-0.99mg/L, and 0.94-4.54mg/L, respectively and all values were below the effluent permissible discharge limits. However, the present study found these metals inhibited D.rerio embryonic development at 0.12mg/L of Cu, and 4.9mg/L of Fe for 96 h-EC50. The present study found that bio-polishing plant installed in mill A effectively removing pollutants especially BOD and the FET test was a useful method to monitor quality and toxicity of the POME final discharge samples.

Holistic process evaluation of non-conventional palm oil mill effluent (POME) treatment technologies: A conceptual and comparative review

Thriving oil palm agroindustry comes at a price of voluminous waste generation, with palm oil mill effluent (POME) as the most cumbersome waste due to its liquid state, high strength, and great discharge volume. In view of incompetent conventional ponding treatment, a voluminous number of publications on non-conventional POME treatments is filed in the Scopus database, mainly working on alternative or polishing POME treatments. In dearth of such comprehensive review, all the non-conventional POME treatments are rigorously reviewed in a conceptual and comparative manner. Herein, non-conventional POME treatments are sorted into the five major routes, viz. biological (bioconversions – aerobic/anaerobic biodegradation), physical (flotation & membrane filtration), chemical (Fenton oxidation), physicochemical (photooxidation, steam reforming, coagulation-flocculation, adsorption, & ultrasonication), and bioelectrochemical (microbial fuel cell) pathways. For aforementioned treatments, the constraints, pros, and cons are qualitatively and quantitatively (with compiled performance data) detailed to indicate their process maturity. Authors recommended (i) bioconversions, adsorption, and steam reforming as primary treatments, (ii) flotation and ultrasonication as pretreatments, (iii) Fenton oxidation, photooxidation, and membrane filtration as polishing treatments, and (iv) microbial fuel cell and coagulation-flocculation as pretreatment or polishing treatment. Life cycle assessments are required to evaluate the environmental, economic, and energy aspects of each process.

ANALISIS CIYCLE COSTING DAN WASTE MANAGEMENT SCENARIOS PADA KOLAM IKAN 4G DAN AZOLLA

One of Mina Kahuripan fish cultivators in Jampang village located in Bogor Regency has innovation and achievements in managing fish and its fish feed, and is the largest fish producer in Bogor Regency. One of the innovations of fish cultivators is the use of a 4G (Four G) fish pond. Besides the fish pond innovation, there is another innovation, namely the use of the Azolla plant. This research aims to analyze the collaboration between Azolla and the 4G pond in waste management scenarios and cycle costing. This research is a qualitative research phenomenon. The data collection technique is done by using observation, interview, documentation, and experiment techniques. Respondents of this study were fish cultivators Mina Kahuripan in Jampang Bogor Village. The results showed that the cycle costing analysis between conventional and 4G fish ponds, it was seen that the production costs in conventional ponds were higher because the media used were all purchased by new categories, while the production costs for 4G fish ponds were lower even though there was a budget for Azolla plant ponds, the quality of the fish produced was guaranteed. Lower production costs are due to the fish cultivators doing waste management from the waste in making 4G fish ponds, resulting in cost efficiency. Another advantage of Waste management scenarios utilizes waste from vegetable and fruit plants that are above the 4G fish pond

Environmental and biotic variables in carp (Cyprinus carpio) ponds: organic vs. conventional management

Organic aquaculture, including carp pond farming, is of growing importance. One of its main characteristics is the health and quality of water environments and maintenance of their biodiversity. In 2013–2014, four organic carp ponds (ORG) in the Waldviertel region (Austria) and four conventional ponds (CONV) in the Třeboň region (Czech Republic), located in the Lainsitz (Lužnice) river basin, were monitored for basic environmental variables, namely hydrochemical and hydrobiological determinants. The aim of this study was to evaluate the performance of organic carp farming technology in the amelioration of carp pond aquatic environment. Aside from temperature, which was probably related to different altitudes, the comparison of physico-chemical environmental variables showed no significant differences between organic and conventional ponds, though dissolved oxygen concentration and saturation, along with turbidity, were higher in ORG ponds, and conductivity was slightly higher in CONV ponds. The mean cumulative richness of zooplankton species was significantly higher in ORG ponds. However, when comparing average richness between both management types, there were significantly fewer rotifer species in ORG fishponds (ORG = 10, CONV = 15; p 0.05), while its biomass was higher in CONV ponds (CONV = 5.31 ± 0.48, ORG = 4.45 ± 2.17 g m−2; p > 0.05).

Modelling solar enhanced waste stabilization pond

Abstract Solar enhanced waste stabilization pond (SEWSP) was modeled in this research. In the analysis, SEWSPs of varying sizes, made of metallic tanks with inlet and outlet valves and solar reflectors, were constructed to increase the incident solar intensity. Wastewater samples collected from the inlet and outlet of the SEWSPs were examined for physico-chemical and biological characteristics for a period of twelve (12) months. The parameters examined were temperature, pH, detention time, total suspended solids, dissolved oxygen, biochemical oxygen demand (BOD5), chemical oxygen demand (COD), algae count, faecal coliforms and E. coli. The efficiencies of the SEWSPs with respect to these parameters fluctuated with depth, location of reflectors and variation in width. The SEWSP with a width of 0.2 m whose reflector was installed at the outlet position gave the highest treatment efficiency. The conventional model was modified to account for solar irradiation. The faecal bacteria removal was significantly higher in the enhanced pond than in the conventional pond at 0.10 level of significance. The verification of the conventional model gave a good correlation of r = 0.882 between the measured and calculated Ne/No with a low standard error of s = 0.010, while the irradiated pond gave a correlation and standard error of r = 0.959 and s = 0.012 respectively. The research revealed that with the incorporation of solar radiation in WSPs, a length/ width/depth ratio of 1:0.2:0.2 can be used in the design of SEWSPs for maximum treatment efficiency.

Evaluating Food Waste Handling Using Trios Monitoring System on Soy Industry in Bali, Indonesia

The purpose of this paper is to analyze a series of operational systems for biofilter technology. The object of research is an area of Wastewater Treatment in the food industry Denpasar, Bali. The Trios System Monitoring Method can be analyzed in three stages of the process of pre-treatment, treatment, stabilization, and three treatments. Biology analyzes settings (giving oxygen, feeding the number of food microorganisms F/M/ ratio, speed of waste flow). The analysis shows that biofilter technology is a technology that uses physical and biological treatment without using chemicals. Physical treatment is carried out by filtration, flotation, sedimentation. Biological treatment is carried out by regulating oxygen delivery with aeration period of 24 hours/day, microorganism feeding F/Mg/ BOD/MLSS/day ratio 0.05-0.2 with 100% proven waste flow BOD decreases by 80% pre-stage treatment. The wastewater is forwarded to the biofilter pond and given physical treatment, biological, and tricking filter in speed regulation, treatment process stage, liquid waste originating from conventional ponds is inserted into the aeration pond with aeration period of 6.0-9.0/hour. Feeding microorganisms F/Mg/BOD/day/MLSS ratio 0.2-0.5 with the waste flow 50%, BOD decreased by 85%. Feeding microorganisms F/Mg/BOD/day/MLSS ratio 0.2 - 0.5 oxygen administration with aeration period of 6.0-9.0/hour, BOD decreased by 85-90%.

Photo-catalytic reactor and detention pond integration: a novel technique for surface water quality enhancement via nano-TiO2

Integration possibility and performance of a fixed-bed photo-catalytic reactor, merged with a detention pond, were examined at scale model. The focus of this study is to overcome the key issues of the conventional detention ponds and provide an enhanced surface water quality via nano-TiO2 as a novel hybrid technology. Photo-degradation of detained water nutrients in newly designed fixed-bed reactor pond (FRP) was studied to observe the impacts of heterogeneous reactions under ultraviolet irradiation. Immobilization of nano-titanium dioxide as catalyst, covering the FRP internal surface, was practiced for comparison and control. Rutile with anatase forms of TiO2 nano-powder (P25) was replaced in cement (white cement as well as Portland) at three dosages (30, 10, and 3%) for optimization purpose. Biodegradable pollutant elimination capability of FRP underpinned by the results for lower nitrate (16%), orthophosphate (25%), and COD (18%) in 2 days retention time, comparatively. Within 21 days, detaining time 26%, 58%. and 47% higher elimination was achieved, respectively. Improved catalyst surface area to reactor volume as well as an optimized retention time, based on streamflow pollution level, were achieved via splitting the FRP into two parts using a divider. FRP inlet was equipped with a flow switcher to capture and detain the first flush from the stormwater separately, while the balance is directed to the second part with a different required holding period. The divider walls were coated with cement-based nano-TiO2 and it also retrofitted applying filter media inside, for sediment-bound pollutant omission which the technique emerged with a greater TSS removal potency of up to 43%.

Earthy and Musty Off‐Flavor Episodes in Catfish Split‐Pond Aquaculture Systems

AbstractThe interest and use of variations of partitioned aquaculture systems (PAS) by the catfish farming industry in the southeastern USA continues to grow. Split‐pond systems, one type of PAS, are designed to improve the management of dissolved oxygen levels and fish waste products (e.g., ammonia) compared with conventional earthen ponds that have been used for many decades. While recent studies of split‐pond systems have focused on design, water flow rates, and management practices, there has not been any assessment of the occurrences and intensities of common “off‐flavor” episodes in these split‐ponds. For the current study, pond water samples were collected from split‐ponds at a commercial fish farm in western Alabama and at a research facility in western Mississippi approximately every 3–4 weeks during the fish grow‐out period (May to November) during 2014 and 2015. In addition, fillet samples from hybrid catfish (Channel Catfish Ictalurus punctatus × Blue Catfish Ictalurus furcatus) were obtained in late summer and autumn from these same split‐ponds. Concentrations of the “earthy” and “musty” off‐flavor compounds geosmin and 2‐methylisoborneol (MIB), respectively, in water and fillet samples were determined. Sensory analysis was also performed on catfish fillets collected during 2014. The highest geosmin and MIB concentrations detected in split‐pond water during the study were 898 and 22,651 ng/L, respectively. Geosmin and MIB concentrations in split‐pond water were often higher in summer and autumn, and concentrations were similar to those reported previously for conventional ponds. The highest geosmin and MIB concentrations detected in fillets during the study were 1,712 and 29,851 ng/kg, respectively. Concentrations of these compounds in fillets and the description and intensities determined via sensory analysis were similar to those reported previously for off‐flavor catfish from conventional ponds. Accordingly, catfish farmers using split‐ponds can use similar management approaches as those used to mitigate earthy and musty off‐flavor problems in catfish raised in conventional ponds (e.g., applications of algicides).