scholarly journals Research on the spread of pathogens-carrying water in the coastal aquaculture system

2021 ◽  
Vol 63 (6) ◽  
pp. 18-22
Author(s):  
Dinh Vuong Nguyen ◽  
◽  
Duc Thang Tang ◽  

This paper presents the application of water source components theory in combination with the MIKE11 modeling tool (1D) to simulate the transport of pathogens-carrying water components in the coastal aquaculture system of Kien Giang province. The simulation results show that pathogens-carrying water spreads at a relatively fast pace and extensively in the system. Drainage schemes have also been proposed to control and minimise the spread of diseases. The application of water source components theory provides the scientific basis to ensure the rational and sustainable design of irrigation system for coastal shrimp-farming areas.

2017 ◽  
Vol 17 (6) ◽  
pp. 1774-1784 ◽  
Author(s):  
L. Zhang ◽  
M. R. Hipsey ◽  
G. X. Zhang ◽  
B. Busch ◽  
H. Y. Li

Abstract Chagan Lake serves as an irrigation storage reservoir for the Qianguo Irrigation Area and an important ecological barrier in western Jilin. The coupled TUFLOW-FV and Aquatic Ecodynamic (AED2) models were used to simulate the hydrodynamic and water quality of Chagan Lake, and propose the water diversion scheme that could improve the water quality to reach Grade III and maintain the ecological water level. The simulation results showed a satisfactory agreement with observations. The total carrying loads of NH3-N, total nitrogen (TN) and total phosphorus (TP) for Chagan Lake were 1,147.6, 3,686.2 and 100.8 t from May to October. The range of the minimum amounts of water diversion to keep the water quality as Grade III and maintain the maximum ecological water level of 131.5 m for TN, TP were separately [32.60, 49.84, 57.19, 63.70, 70.91], [117.25, 135.26, 168.17, 190.65, 218.32] million m3 and the corresponding reduction amounts of farmland drainage for TN, TP were separately [4.03, 0, 0, 0, 0], [73.08, 61.88, 50.23, 40.94, 31.98] million m3 under the rainfall guarantee rates of 10%, 20%, 50%, 75%, 90%, respectively. The simulation results provide a scientific basis for the water quality improvement and ecological water supplement required for the interconnected river–lake system network (IRLSN) in Western Jilin Province.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 524a-524 ◽  
Author(s):  
Kent Cushman ◽  
Thomas Horgan

Tomato was grown in Fall 1997 with swine effluent or commercial soluble fertilizer in a plasticulture production system. Four cultivars, `Mountain Delight', `Celebrity', `Equinox', and `Sunbeam', were transplanted to raised beds with plastic mulch and drip irrigation. Preplant fertilizer was not applied. Effluent from the Wiley L. Bean Swine Demonstration Unit's secondary lagoon was filtered through in-line screen filters and applied directly to the plants through the irrigation system. Toward the end of each application, sodium hypochlorite was injected in the line to achieve a free chlorine concentration of ≈1%. Clogging of filters or drip emitters did not occur. Control plants received 100 ppm N from soluble fertilizer injected in irrigation lines supplied by a municipal water source. Number and weight of tomatoes from plants receiving swine effluent were equal to that of plants receiving soluble fertilizer. No differences in fruit quality were evident between treatments. Plant dry weight was also equal for three out of four cultivars. No differences in soil characteristics were detected between treatments after the study. Chemical analysis of the effluent showed a pH of 7.8 and nutrient concentrations of ≈110 ppm NH4-N, 57 ppm P2O5, 150 ppm K2O, and trace amounts of Cu and Zn. Though no differences in yield were detected in this study, the effluent's high pH and high NH4-N content need to be managed more closely for commercial tomato production.


Author(s):  
K. Nagarajan ◽  
S. Ramya ◽  
T. Thangamani ◽  
A. Selvaperumal ◽  
T. Arthi

The parameters require for maintaining the crop's health and the integrity of the irrigation system has a relation with quality of irrigation water. In Micro irrigation appropriate filtration is very much important to prevent clogging. Filtration unit is one of the main components in micro irrigation system that too, Primary filter is more important to be installed along with the unit, when the water source is from open reservoir and other water sources. Though it is essential, the primary filter is not being installed by the farmers due to its high cost. Hence this study is an attempt to fabricate low-cost filter and to evaluate its performance with different filter media layer. A low-cost primary filter for drip irrigation system is fabricated. Different filter media layer like silex sand (fine silex, coarse silex), pebbles with different sizes are selected. The results revealed that the removal efficiency of filter using silex sand and pebbles were 71% in terms of turbidity, 78% in terms of total suspended solids removal at flow rate of 12 m3 /hr. This fabricated low-cost filter will be cost effective for small farm applications.


Author(s):  
S Noorak ◽  
S Rakkhiaw ◽  
K Limjirakhajornt ◽  
A Uppabullung ◽  
T Keawtawee ◽  
...  

Author(s):  
Hana Kubátová

The paper presents the principles of using Petri Net formalism in hardware design courses, especially in the course “Architecture of peripheral devices”. Several models and results obtained by student individual or group projects are mentioned. First the using of formalism as a modeling tool is presented consecutively from Place/Transition nets to Coloured Petri nets. Then the possible Petri Nets using as a hardware specification for direct hardware implementation (synthesized VHDL for FPGA) is described. Implementation and simulation results of three directly implemented models are presented.


2019 ◽  
Vol 11 (3) ◽  
pp. 895 ◽  
Author(s):  
Liguo Zhang ◽  
Zhanqi Wang ◽  
Ji Chai ◽  
Yongpeng Fu ◽  
Chao Wei ◽  
...  

The quantitative estimation of non-point source (NPS) pollution provides the scientific basis for sustainability in ecologically sensitive regions. This study combined the export coefficient model and Revised Universal Soil Loss Equation to estimate the NPS nitrogen (NPS-N) and NPS phosphorus (NPS-P) loads and then evaluated their relationship with Primary Industrial Output Value (PIOV) in the water source area of the middle route of South-to-North Water Diversion Project (SNWDP) for 2000–2015. The estimated results show that: (1) dissolved nitrogen (DN) load increased 0.55%, and dissolved phosphorus (DP) load decreased 4.60% during the 15 years. Annual loads of adsorbed nitrogen (AN) and adsorbed phosphorus (AP) increased significantly before 2005 and then decreased after 2005. Compared with 2000, AN and AP loads in 2015 significantly decreased by 32.72% and 30.81%, respectively. Hanzhong Basin and Ankang Basin are key areas for controlling dissolved pollution, and southern and northern regions are key areas for adsorbed pollution. (2) From 2000 to 2005, NPS pollutants and PIOV showed weak decoupling status. By 2015, NPS pollutants had strong decoupling from PIOV in most counties. (3) Land use has been the main source of NPS-N and NPS-P pollution, accounting for about 75% of NPS-N and 50% of NPS-P based on the average value over the study period. In the future, various measures—such as returning cropland to forest and reducing the number of livestock—could be adopted to reduce the risk of NPS pollution. NPS pollution caused by livestock was grown over the past 15 years and had not yet been effectively controlled, which still needs to be urgently addressed. Collecting ground monitoring data and revising parameters are effective means to improve the accuracy of simulation, which deserve further study. The results will also provide scientific support for sustainable development in similar regions.


2014 ◽  
Vol 908 ◽  
pp. 425-428
Author(s):  
Hao Chen ◽  
Fu Li Chen ◽  
Yong Ying Zhu ◽  
Ming Zeng ◽  
Chen Sun ◽  
...  

By the tracers of dissolved conservative substance, establishing the convection diffusion numerical model of water exchange in the bay. The water exchange simulation results derive the half-exchange period of each region.And based on the hydrological data,model results show the tidal current field and the half-exchange period,analyzing the water exchange properties and the convective transport of pollutants to the Pulandian Bay.The numerical simulation results provide the scientific basis and basic data for the sea area construction and environmental protection.


Irriga ◽  
2004 ◽  
Vol 9 (2) ◽  
pp. 136-149 ◽  
Author(s):  
Tulio Assunção Pires Ribeiro ◽  
José Euclides Stipp Paterniani ◽  
Rogério Pereira da Silva Airoldi ◽  
Marcelo Jacomini Moreira da Silva

O EFEITO DA QUALIDADE DA ÁGUA NO ENTUPIMENTO DE  EMISSORES E NO DESEMPENHO DE FILTROS UTILIZADOS NA IRRIGAÇÃO POR GOTEJAMENTO   Túlio Assunção Pires Ribeiro; José Euclides Stipp Paterniani; Rogério Pereira da Silva Airoldi; Marcelo Jacomini Moreira da SilvaDepartamento de Água e Solo, Faculdade de Engenharia Agrícola, UNICAMP, Campinas, SP, [email protected]   1 RESUMO  O presente trabalho teve como objetivo proceder a investigação experimental de uma fonte hídrica superficial, utilizada em um sistema de irrigação por gotejamento, bem como verificar sua influência na obstrução dos gotejadores e no desempenho de dois filtros um de disco e outro de mata sintética não tecida. A água de irrigação foi clorada, empregando-se hipoclorito  de sódio. Utilizou-se água provinda de um reservatório aberto, onde foi instalado um módulo de irrigação localizada para o estudo.  Analisou-se a variação temporal da qualidade da água durante um ano, onde considerou-se os principais parâmetros físicos, químicos e biológicos da água que causam problemas de entupimentos nos emissores. O desempenho dos filtros foi feito através da comparação das concentrações dos efluentes dos filtros de disco (usualmente utilizado para este fim) e manta sintética não tecida,  em relação aos parâmetros físicos e biológicas. O grau de obstrução dos emissores foi avaliado através de ensaios de vazão que determinaram a uniformidade de distribuição da água através de dois índices, onde variou-se o número de emissores amostrados.  A pesquisa foi desenvolvida em quatro etapas de 30 dias, realizadas em diferentes estações do ano. Os resultados apontaram na água de irrigação, que os parâmetros químicos pH e o ferro apresentaram médio risco de entupimento e sulfetos de hidrogênio mostraram alto risco de entupimento.  Não houve uma diferença no desempenho do filtro de manta e de disco com relação aos parâmetros físicos e biológicos de seus efluentes.  Os valores das médias dos índices de uniformidade de distribuição de água foram bem próximos para as duas parcelas que utilizaram os dois filtros de manta e disco.  UNITERMOS: irrigação localizada, índice de uniformidade, filtração, manta sintética não tecida, tratamento químico  RIBEIRO, T. A. P.; PATERNIANI, J. E. S.; AIROLDI, R. P. da S.; SILVA, M. J. M. da THE WATER QUALITY EFFECT IN THE CLOGGING OF EMITTERS AND THE PERFORMANCE OF FILTERS UTILIZED IN THE TRICKLE IRRIGATION  2 ABSTRACT  The present work aimed to carry out an experimental investigation of a superficial water source utilized in trickle irrigation as well as verify its influence in the clogging of drippers and in the performance of two filters: a disc one and a non woven synthetic one. The irrigation water was chlorinated with sodium hypochlorite. The water used in this experiment was from an open reservoir where an experimental trickle irrigation system was installed. The temporal variations of the water quality was assessed for one year, considering the main physical, chemical and biological parameters of the water that causes clogging in the emitters. The filter performance was assessed by comparing the effluent concentration in the disc filters (normally used for this purpose) and in non-woven synthetic fabric, for physical and biological parameters. The emitter obstruction degree was assessed through flow tests which determined the uniformity of water distribution through two rates where the number of sampled emitters varied. The research was developed in four 30-day stages, carried out in different seasons of the year. For the irrigation water, the results indicated that the chemical parameters (pH) and iron showed a medium risk of clogging whereas hydrogen sulphites showed a high risk of clogging. There was not a difference in the performance of fabric and disc filters in relation to physical and biological parameters of their effluents. The average values for  water distribution uniformity rates were pretty close for the two blocks that utilized both disc and fabric filters.  KEYWORDS: trickle irrigation, uniformity index, filtration, non-woven synthetic fabrics, chemical treatment


2019 ◽  
Vol 20 (2) ◽  
pp. 63
Author(s):  
Dea Nafila ◽  
Rustadi Rustadi ◽  
Djumanto Djumanto

The aim of this study was to determine the preference for plankton as natural feed by giant gourami, walking catfish, and red nile on intensive aquaculture system. The study was designed using Completely Randomized Design (RAL), with two replications. Each fish was kept in six concrete tanks with dimension 2x2x1 m³ and 60 cm water level. Water source were from wells. Commercial pellet feed was given in three times daily ad libitum. Water samples were filtered and two individual fish were collected for plankton samples from pond water and alimentary canal, respectively, every two week, simultaneously with water quality measurements. Plankton samples were preserved using 5% formaldehyde and was observed under a compound light microscope with 100x magnification. The amount of plankton in the alimentary canal was converted to volume. Data were analyzed descriptively. The result showed that the volume contents proportion of plankton in the alimentary canal was less than 1%. The volume of plankton proportion in the alimentary canal of red nile were found the most than other fish. Each fish had the same preference of plankton of Lepocinclis and Scenedesmus, but different from other species of plankton. The plankton that utilized by giant gouramy were Crucigenia, Diadesmis and Navicula, whereas walking catfish was Pediastrum, and red nile was Microcystis. The plankton that preferred by giant gouramy were Crucigenia, Oscillatoria, Splirullina, and Synedra, walking catfish was Navicula, while red nile were Chrysamoeba and Tintinnidium.


2020 ◽  
Vol 3 (2) ◽  
pp. 158-165
Author(s):  
Winardi Winardi ◽  
Azmeri Azmeri ◽  
Masimin Masimin

The Pandrah Irrigation Area is a technical irrigation network whose water source comes from the Krueng Pandrah river. Pandrah Weir was built in 1987 located in Samagadeng Village, Pandrah District, Bireuen Regency. It has an area of 1,203 hectares of irrigated rice fields. In its development, the damage that occurs in the Pandrah irrigation area also cannot be ignored. It is necessary to review it by assessing the performance of the irrigation system. The purpose of this study was to determine the performance index of the Pandrah irrigation system using the MASSCOTE (Mapping System and Service for Canal Operation Technique) method approach. The assessment of the performance index of the Pandrah irrigation system using the MASSCOTE method approach is carried out by evaluating the Rapid Appraisal Procedure (RAP) on four main indicators, namely service indicators, indicators for Farmers Using Water (P3A), indicators for the operator's Human Resources (HR). In the evaluation of the RAP, it is the value of observations of the respondents of OP officers and P3A farmers who are presented in a questionnaire to cross-assess each respondent in irrigation management. The results of the research on the performance appraisal of the Pandrah irrigation system based on the MASSCOTE method with RAP evaluation showed that the performance index of the absolute value (Level of Service) was 3.05. Hence, the performance index of the Pandrah irrigation system in the existing conditions was in the Good classification. This index and classification value shows the value of irrigation operations in fulfilling services from irrigation management carried out by operators / OP officers and felt by irrigation service beneficiaries, namely P3A farmers.


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