Clogging Rate Research Articles

Parameter Optimization of Spiral Step Cleaning Device for Ratooning Rice Based on Computational Fluid Dynamics-Discrete Element Method Coupling

Ratooning rice plants have a high moisture content and strong adhesion during harvesting. Traditional cleaning devices are prone to clogging when processing ratooning rice, resulting in a series of problems such as high grain loss rate and high grain impurity rate. In response to the above issues, this article adopts the CFD-DEM coupling method to design a spiral step cleaning device. A detailed analysis was conducted on the influence of the cone angle and thickness of the spiral-stepped skeletons on the flow state, and flow velocity and pressure distribution cloud maps were obtained under different structural parameters. The vortex morphology under different thicknesses of the spiral-stepped skeletons was compared, and the structural parameters of the device were determined. The motion trajectory and distribution of impurity particles under different inlet flow velocities were analyzed using data superposition, and the appropriate inlet flow velocity range was determined. A test bench was built, and a three-factor quadratic regression orthogonal rotation combination experiment was conducted with fan speed, feeding rate, and device inclination angle as experimental factors. The results of the bench test show that the performance index reaches its optimum when the device inclination angle, fan speed, and feeding rate are 2.47°, 2906 r/min, and 4.0 kg/s, respectively. At this time, the grain impurity rate, grain loss rate, and sieve clogging rate are 2.21%, 2.15%, and 3.5%, respectively. Compared to those of traditional cleaning equipment, these value are reduced by 44.5%, 39.6%, and 83.9%, respectively. This study can provide ideas for the design of ratooning rice cleaning devices.

Wear characteristics evolution of corundum wheel and its influence on performance in creep feed grinding of nickel-based superalloy

Wheel wear is an unavoidable occurrence in the process of creep feed grinding nickel-based superalloys, leading to reduced geometric accuracy, productivity, and surface integrity. Therefore, quantifying wheel wear forms and grinding performance is essential to minimize adverse impacts and optimize grinding processes. This study investigates the evolution of wheel wear and its consequences on grinding loads, chip formation, and surface quality. The results indicate that as the material removal volume (MRV) increases in the life cycle of the grinding wheel, the accumulation of timing damage leads to various forms of wear, mainly including grain fractures, material adhesion, attritious wear, and wheel clogging. The macro effects of the grinding ratio exhibit an initial increase followed by a subsequent decrease. At the micro level, the height of grain protrusions decrease, causing deviation from the normal distribution. Upon reaching the steady wear stage with an MRV of 9990 mm3, the wear flat rate and wheel clogging rate increase to approximately 10 % and 16.7 %, respectively. This indicates a significant rise in grinding thermo-mechanical load, serving as key indicators for evaluating the durability of grinding wheel. The presence of dull grains and material adhesion exacerbates the rubbing and ploughing effects, causing a transition of chip morphology from continuous flow to shear deformation, while heightened plastic pile-up contributes to elevated surface roughness. The intense thermo-mechanical coupling results in the formation of redeposited material and burn defects on the surface.

Implementation of sediment separator core hole in an effort to reduce the filter clogging rate of CAT 16M Grader


 
 
 
 The Cat 16M Grader is a heavy equipment that is widely used to support mining operations. The development of this heavy equipment is required to use biodesel fuel (B30). The problem with B30 fuel is oxidation which results in the formation of sediment and can cause filter clogging. Filter clogging can affect engine power and filter replacement time. From these problems, the researcher proposed to modify the number of sediment separator core holes to reduce the filter clogging rate on the Cat 16M grader. Modified number of sediment separator core holes are 40, 20 and 10 holes with 8 mm hole dimension. Data was collected experimentally by implementing the modified sediment separator core on a Cat 16M grader for 250 hours of operation. The research resulted in the number of sediment separator core holes 10 at 250 hours of operation producing the highest sediment volume of 92 ml, the filter with the lowest clogging rate and the lowest fuel pressure difference. In addition, using the number of sediment separator cores 10 at 250 hours of operation produces the highest engine power, the highest filter clogging efficiency and has a high economic value.
 
 
 

Communication Strategies in the Fast Food Industry in Romania

The article analyzes the existing technologies and means of mechanization of melon and cucumber seeds, which showed that the imperfection of existing equipment is, first of all, the lack of necessary specialized machines and leads to unacceptable rates of loss and clogging of seeds. The research projects were carried out to study the mechanical and technological properties of placenta particles and seeds of melon and cucumber, the results of which were used to theoretically substantiate the process of obtaining seeds. Experimental studies of the technological process of obtaining seeds for these crops, as well as their analysis, made it possible to substantiate the boundaries of the main operating modes of the new complex of machines.

Safety and efficacy of direct percutaneous endoscopic jejunostomy tube placement compared with surgical jejunostomy: a tertiary care analysis

Background and AimsJejunostomy tube placements provides enteral access for feeding in eligible patients who cannot meet the nutritional needs by mouth. They can be surgically placed laparoscopically (lap-J) or using conventional open laparotomy (open-J) approach. Recently, direct percutaneous endoscopic jejunostomy (DPEJ) has emerged as an alternative because of its low cost and shorter recovery times. We sought to retrospectively compared the procedural success rates and complications of these methods. MethodsPatients were identified by a querying of our health system patient database and the departmental database of patients who underwent DPEJ. The patients were divided into three cohorts based on the procedure: DPEJ, lap-J, and open-J. Patient age and BMI, procedure success rate, and complications rate were compared among the three groups. Results201 patients met inclusion criteria (65 DPEJ, 111 lap-J and 25 open-J). Procedural success rates were similar between the 3 groups (DPEJ 96.9%, Lap-J 99.1%, Open-J 100%, p=0.702). Rates of infection and bleeding were also similar between the 3 groups. There were no cases of GI perforation. Tube dysfunction for any reason that required complete removal and/or replacement within 90 days occurred more often in the surgical groups than in the DPEJ group (DPEJ 0%, lap-J 35.1%, open-J 40.0%, p<0.001). This was driven largely by increased rates of tube clogging and tube dislodgement in the surgical groups. ConclusionDPEJ is a safe and effective alternative to surgical jejunostomy in eligible patients and may be associated with decreased complication rates at 90-days.

Experimental study on clogging of three different types of emitters with similar properties

AbstractThe drip irrigation process has been designed to reduce water losses, and to combine irrigation, with the supply of fertilizers. However, in drip irrigation systems, the clogging of emitters is a major problem that significantly reduces the performance of drip irrigation systems. The water used in these systems is generally loaded with suspended matter, which might cause clogging of the emitters. This work was carried out in order to evaluate the clogging rate in three different types of emitters with roughly similar flow rates, tested in an experimental drip irrigation system, using water pumped from the Sebou River. Thus, a compensating‐pressure emitter named E1 and two non‐compensating‐pressure emitters named E2 and E3 were tested. Each dripper was subjected to 112 irrigations, which lasted 397 h and were spread over a period of 2 months. To evaluate the hydraulic performance of the emitters, the following three coefficients were used to measure the effect of clogging: (i) the variation of the flow ratio (Dra), which reflects the degree of clogging; (ii) the emission uniformity coefficient (EU); and (iii) the Christiansen uniformity coefficient (CU). No emitters became completely clogged during the experiment. However, as the clogging rate increased, the average flow rates measured in some emitters at the end of the test had decreased by 89% compared to the initial flow rates. During the experiment, flow fluctuations were observed during the evolution of the clogging, which could come from a partial recovery of flow.

Assessment of bed clogging in surface water reservoirs under different hydrologic conditions

Physical clogging of porous media plays an important role in controlling their hydraulic conductivity. This study investigates how uniformly graded medium-to-coarse sand in a reservoir’s bed performs in response to the inflow of turbid water with fine suspended sediments. Different particle sizes, heads, and concentrations were simulated to cover a range of hydrologic conditions. A 1D sand column was used with three bed material sizes and three suspended particle sizes. Seven particle size ratios were tested under a constant head. Four heads and three suspended sediment concentrations are also evaluated. It was concluded that the decline in the relative hydraulic conductivity of the bed material is directly proportional to the ratio of sediments-to-bed particle sizes. Increasing the concentration of suspended sediments accelerated the rate of clogging, while bigger heads increased the depth of clogging. The study highlights how physical clogging affects the water balance in surface reservoirs and threatens the safety of dams.

Synthesis of length-tunable DNA carriers for nanopore sensing.

Molecular carriers represent an increasingly common strategy in the field of nanopore sensing to use secondary molecules to selectively report on the presence of target analytes in solution, allowing for sensitive assays of otherwise hard-to-detect molecules such as small, weakly-charged proteins. However, existing carrier designs can often introduce drawbacks to nanopore experiments including higher levels of cost/complexity and carrier-pore interactions that lead to ambiguous signals and elevated clogging rates. In this work, we present a simple method of carrier production based on sticky-ended DNA molecules that emphasizes ease-of-synthesis and compatibility with nanopore sensing and analysis. In particular, our method incorporates the ability to flexibly control the length of the DNA carriers produced, enhancing the multiplexing potential of this carrier system through the separable nanopore signals they could generate for distinct targets. A proof-of-concept nanopore experiment is also presented, involving carriers produced by our method with multiple lengths and attached to DNA nanostructure targets, in order to validate the capabilities of the system. As the breadth of applications for nanopore sensors continues to expand, the availability of tools such as those presented here to help translate the outcomes of these applications into robust nanopore signals will be of major importance.

Research on the clogging law of floating particles on the rain grate of road surface

PurposeSince surface runoff clogs stormwater grates, leading to deterioration of drainage capacity, and also it is difficult to complete the study with actual dimensions in experiments, a numerical simulation work was established in this study to investigate the surface runoff clogging stormwater grate patterns. The purpose of this study is to describe the mechanisms of storm grate clogging and storm well deposition for different flow rate floods and granular materials.Design/methodology/approachIn the work of this study, the volume of fluid (VOF) method and the discrete element method (DEM) are used to solve the gas–liquid and particle flows. In order to solve the evolution of the gas–liquid interface during surface runoff, the VOF was used. To simulate the rain grate and set up different material particles to represent the surface floating materials, the DEM was utilized.FindingsThe research results show that the clogging distribution and clogging rate of the rainwater grate are closely related to the fluid flow velocity and the physical characteristics of the particles, and the higher the clogging rate of the rainwater grate and the higher the number of particles deposited in the rainwater well at the same surface runoff velocity, the higher the density of the clogged particles. The surface runoff velocity (0.5 m/s, 1 m/s) shows that the rapid change of particle movement state at high runoff velocity makes the particle clogging more obvious.Originality/valueA multi-scale CFD-DEM approach was used to simulate the particulate motion of the road surface with different incoming runoff velocities. The innovative use of DEM to model the storm grate simulation ensures the accuracy of the traction model.

Field performance monitoring of pervious concrete pavements

Pervious concrete pavements (PCP) have been successfully constructed in low-to-medium volume roads attributed to their sustainability benefits. Several studies have investigated the hydrological performance of PCPs, but limited attention has been given to the structural and environmental aspects. Thus, the objective of this study was to monitor the structural, hydrological and environmental performance of two PCP parking lots built using in-situ and ready-mix methods. Structural distresses were classified based on the distress identification manual, while the infiltration tests were performed every three months for three years to quantify the clogging rate. Joints/edges formed the weakest zones, while inefficient maintenance caused 98% clogging within 18 months. Further, in-situ mixing was 17% cheaper and 0.74% carbon-intensive than ready-mix technology. Overall, this research is envisioned to pave way for the development of guidelines that classify distresses and severity levels specific to PCPs, which also cover adequate maintenance recommendations for field implementation.

Applying lysozyme, alkaline protease, and sodium hypochlorite to reduce bioclogging during managed aquifer recharge: A laboratory study

Alleviating bacterial-induced clogging is of great importance to improve the efficiency of managed aquifer recharge (MAR). Enzymes (lysozyme and alkaline protease) and sodium hypochlorite (NaClO) are common biological and chemical reagents for inhibiting bacterial growth and activity. To investigate the applicability of these reagents to reduce bioclogging, percolation experiments were performed to simulate a weak alkaline recharge water infiltration through laboratory-scale sand columns, with adding 10 mg/L lysozyme, alkaline protease, and NaClO, respectively. The results showed that, with the addition of lysozyme, alkaline protease, and NaClO, the average clogging rates (the reduced percentages of relative saturated hydraulic conductivity of the sand columns per hour during the percolation experiments) were 0.53%/h, 0.32%/h and 0.06%/h, respectively, which were much lower than that in the control group (0.99%/h). This implied that bioclogging could be alleviated to some extent following the treatments. For further analyzing the mechanisms of the regents on alleviating bioclogging, the bacterial cell amount and extracellular polymeric substances (EPS) concentration were also measured to study the effects of lysozyme, alkaline protease, and NaClO on bacterial growth and EPS secretion. Lysozyme and alkaline protease could disintegrate bacterial EPS by hydrolyzing polysaccharides and proteins, respectively, while they had little effect on the bacterial cell amount. The addition of NaClO significantly decreased the bacterial cell amount (P < 0.05) and thus greatly alleviated bioclogging. Although the lowest average clogging rate was achieved in the NaClO group, it can generate disinfection by-products that are potentially harmful to the environment and human health. Therefore, the biological-based method, i.e., enzyme treatment, could be a promising option for bioclogging control. Our results provide insights for understanding the mechanisms of lysozyme, alkaline protease, and NaClO to alleviate bioclogging, which is of great importance for addressing the clogging problem during MAR activities and achieving groundwater resources sustainable utilization.

Spatiotemporal difference of leachate production and its impact on the development and dynamics of LCS clogging

Due to the complexity of industrial solid waste, heavy metals and organics can be enriched in leachate. While leachate is difficult to handle, it can also cause clog of the leachate collection system (LCS), increasing the risk of leakage. Therefore, it is necessary to study the clogging process of LCS in industrial solid waste landfills (ISWLs). In this study, the prediction of the clogging process and hydraulic conductivity evolution of the LCS in ISWL were carried out through laboratory experiments and model simulations. The results show that the LCS of ISWLs in China faces severe clogging challenges. First, the rate of clogging is inversely proportional to the rate of leachate production. Then, it was found that the main influencing factor was infiltration conditions (precipitation and capping systems). Under accelerated infiltration conditions, the time for complete clogging of the leachate drainage pipes was shortened from the initial 26–735 years to 11–315 years. The time to complete LCS clogging was shortened from the initial 78–2205 years to 32–945 years. In addition, the acceleration of the clogging process was fully consistent with the increase in leachate production. In particular, when the net infiltration volume increases from 0 to 50 mm, the clogging process is significantly accelerated. After greater than 50 mm, the effect on the clogging process gradually decreases. This provides a reliable theoretical basis for accurately predicting the clogging process of LCS.

Flow dynamics through discontinuous clogs of rigid particles in tapered microchannels

Suspended particles flowing through complex porous spaces exhibit clogging mechanisms determined by factors including their size, deformability, and the geometry of the confinement. This study describes the clogging of rigid particles in a microfluidic device made up of parallel microchannels that taper from the inlet to the outlet, where the constriction width is approximately equal to the particle size. This converging geometry summarizes the dynamics of clogging in flow channels with constrictions that narrow over multiple length scales. Our novel approach allows the investigation of suspension flow dynamics in confined systems where clogs are formed both by sieving and bridging mechanisms simultaneously. Here, flow tests are conducted at constant driving pressures for different particle volume fractions, and a power-law decay which appears to be peculiar to the channels’ tapered geometry is observed in all cases. Compared to non-tapered channels, the power-law behavior shows flowrate decay is significantly weaker in tapered channels. This weaker flowrate decay is explained by the formation of discontinuous clogs within each channel. Micrographs of the clogged channels reveal clogs do not grow continuously from their initial positions around the channels’ outlet. Rather, new clogs spanning the width of the channel at their points of inception are successively formed as the cake grows toward the inlet area in each microchannel. The results show changes in particle volume fraction at constant driving pressure affect the clogging rate without impacting the underlying dynamics. Unexpectedly, analyses of the particles packing behavior in the microchannels, and post-clogging permeability of the microfluidic devices, reveal the presence of two distinct regimes of driving pressure, though only a small portion of the total device volume and channels surface area are occupied by clogs, regardless of the particle volume fraction. This novel investigation of discontinuous clogging over multiple particle diameters provides unique insights into additional mechanisms to control flow losses in filtration and other confined systems.

Aerated drip irrigation increased the emitter clogging risk of the Yellow River water drip irrigation

AbstractThe influence of aeration on the emitter clogging of Yellow River water drip irrigation was evaluated, and reasonable measures to slow down the emitter clogging were investigated. A short‐cycle intermittent irrigation test and sediment settlement test were performed under the conditions of aeration and no aeration. The results showed that aeration accelerated the settlement of sediment at the inlet of the flow channel, increased the clogging rate of the flow channel inlet and exacerbated the clogging of the emitter. With the decrease of sediment particle size, aeration increased sediment deposition and emitter clogging. With the increase fencing inlet area, the effect of aeration on sediment settlement and emitter clogging decreased. Under aeration conditions, the upward position of the emitter outlet significantly reduced the mass of emitter blockage and increased the emitter flow compared with the downward positioning of the outlet. Thus, the recommendation is to select an emitter with a large area of fencing inlet, and the outlet of the emitter should be positioned upwards in order to improve the anticlogging performance of the emitter for Yellow River water aerated drip irrigation.

Rechargeable stormwater biofilters: In situ regeneration of PFAS removal capacity by using a cationic polymer, polydiallyldimethylammonium chloride

Conventional stormwater biofilter media such as sand and compost have limited capacity to remove PFAS due to the exhaustion of attachment sites with pollutants and other stormwater constituents. Replacing exhausted filter media is expensive whereas in situ regeneration of their adsorption capacity can be cost-effective. This study demonstrates that in situ application of cationic polymers such as polydiallyldimethylammonium chloride (PDADMAC), a drinking water coagulant, could regenerate the filter media capacity to remove anionic PFAS. The benefit of PDADMAC increased with a decrease in PFAS carbon chain length: the removal of PFBA increased by 9.9 ± 1.8 times while the removal of PFOA only increased by 0.3 ± 0.03 times. The result indicates the application of the cationic polymer can help remove short-chain PFAS, the ones that are most difficult to remove by typical organic amendments such as activated carbon and biochar. Despite being used as coagulants, the addition of PDADMAC did not negatively affect the clogging rate of the biofilters in the presence of suspended sediments. Surprisingly, biofilters exposed to PDADMAC required 35.3% more suspended sediments than the biofilters without PDADMAC to reduce the hydraulic conductivity below half of the initial value. PDADMAC application reduced the release of colloids from the biofilter media during intermittent flow, thereby decreasing the potential of the colloid-facilitated release of adsorbed PFAS. The adsorbed PDADMAC in the biofilter was not degraded, indicating that applied PDADMAC could last long and continue to remove PFAS in the biofilter. Thus, in situ application of cationic polymers can help regenerate the PFAS removal capacity of conventional biofilters.

Characterization of the Degradation of HEPA Filters Protected by Different Spark Arrestors for Various Cutting Means and Cutting Conditions

Abstract The ageing of the nuclear installations induces new challenges regarding the containment of radioactive matter especially airborne contamination. The purification of the air using fibrous filters is the most widely used technology for the containment of this contamination. However, to ensure their role, they need to be protected. The release of incandescent particles cutting processes could reduce their efficiency. Many spark arrestors are available to protect the filters from hot particles. They are designed to be implemented upstream the filter. Three technologies of spark arrestors have been tested when they are exposed to a grinder or a plasma cutting process. The experiments have been performed for two different filters (450 and 1500 m3/h flow rate). The particle size distribution of the aerosol produced by a plasma torch cutting has been measured and shows two characteristic modes for this kind of generation process. The filtration efficiency of the high efficiency particulate air (HEPA) filter has been measured before and after the cutting (NF-EN-ISO-16170). During the experiments, the pressure drop of the HEPA filters has been measured to estimate their clogging rate. Results show that the plasma cutting is a more penalizing cutting process compared to metal grinder and that the metallic fibrous medium with the finest mesh has the better performance to protect filters from sparks. The cut length and the distance between the filter and the spark arrestor have also been studied, showing a limited impact on the degradation of the filtration efficiency.

Effect of raindrop splashes on topsoil structure and infiltration characteristics

Raindrop splashing causes pore blockage in topsoil and reduces its infiltration capacity. In this study, simulated rainfall and infiltration tests were used to analyze the relationship between differences in the topsoil structure and the infiltration capacity of Lou soil on the Loess Plateau under different raindrop splashing conditions. The results show that, compared with soil existing under no raindrop splashing, the structure of the disturbed topsoil was altered, and the number of aggregates (A) and the three-dimensional fractal dimension (FD) degree were significantly increased (P < 0.05). At the same time, the pore volume (VP) and macroporosity (PL) were significantly reduced (P < 0.05). Aggregates splashed by 4.05 mm diameter raindrops were the most severely disturbed, and the pore clogging rate (CR) reached as high as 46.40%. After the broken aggregates blocked the pores, a dense and low permeable crust was formed on the topsoil, and it decreased the cumulative amount of infiltration and the infiltration rate. With increasing splash frequencies and raindrop diameters, the topsoil infiltration rate decreased gradually, and the soil infiltration reduction effect (IR) increased significantly. Three splashes later, the IR effect reached 94.21%. The study reveals the processes and mechanisms driving changes in soil infiltration characteristics from the perspective of changes in topsoil structure caused by raindrop splashing.

Exploring the suitability of using Foam concrete as pore pressure dissipation measure for slope Stability: A state of art review

Landslides are one of the major factors leading to disruption of transportation and urbanization of north-eastern India (NEI). The primary reasons are continuous precipitation and alarming seismicity at frequent intervals. Among various factors which can trigger landslide, most common is the increase of pore water pressure (PWP). This in turn increases the weight of the backfill and subsequently contribute to the overturning moment. Hence, measures to extract the pore water (PW) from the backfill through provision of drainage path is an efficient and widely followed approach to mitigate landslides. This paper presents a detailed overview on various landslides which have happened in the NEI during rainfalls and earthquake events, confirming these as two main triggering factors. Later, the limitations of various conventional landslide prevention techniques is also discussed. Though RWs are commonly adopted slope stabilization techniques, many case studies exist in where even RWs had failed to stabilize the slopes particularly where the slopes with higher groundwater table were subjected to heavy precipitation. The primary reason of failure was development of excess PWP behind RWs. While weep-holes in the RW play a critical role in dissipating PWP of the backfill, these are clogged resulting in the failure of the RWs. The fact cannot be denied that the effectiveness of the weep-hole depends upon its design, construction as well as its maintenance.Recently few researchers have shown that the Foam concrete (FC), a type of lightweight concrete, act as an excellent draining material to facilitate PW discharge for slope stabilization owing to its high permeability. Further, as the density of air voids in FC is more, rate of clogging is expected to be lesser, thus demanding lesser maintenance when compared to conventional weep-holes. This way, the need of regular maintenance of weep-holes can be minimized by use of FC. It should be highlighted here that though FC has lot of potential to be use in aforementioned application, there is not much of research exist in the literature on use of FC for PWP dissipation application. In this light, the present work also presents an in-depth review on permeation characteristics of FC, enumerating the PWP dissipation mechanism with the help of case studies from the literature.

Effect of minimal pre-treatment on reverse osmosis using surface water as a source

Reverse osmosis is increasingly used in drinking water supply for treatment of fresh water sources which can directly result in high quality water. In practice reverse osmosis is never applied directly on fresh water sources, predominantly because of the occurrence of membrane fouling. Strategies to control membrane fouling in reverse osmosis without expensive and extensive pre-treatment include low flux operation, increase cross-flow velocities and improved (periodic) hydraulic cleaning. The objective of this research is to technically and economically compare minimal pre-treated reverse osmosis to state-of-the art ultrafiltration pre-treated reverse osmosis in surface water treatment to obtain high quality water. A parallel reverse osmosis system with six parallel 2540-type spiral wound membrane elements has been systematically operated during several months with only screens pre-treatment before reverse osmosis. A minimal pre-treated reverse osmosis system using only screens on surface water did not result in stable reverse osmosis operation, however, the ultrafiltration pre-treated reverse osmosis system also failed in the longer run. Lowering the membrane flux from 25 L/m2.h to 10 L/m2.h in minimal pre-treated RO resulted in an approximately 10-fold decrease of the membrane fouling rate, while not influencing the pressure drop increase. Periodical air water cleaning in minimal pre-treated RO resulted in an approximately 4-fold reduction of the spacer clogging rate, while not affecting the membrane fouling rate. The total cost of a minimal pre-treated low flux (10 L/m2.h) operated RO was significantly lower (0.46 €/m3) compared to state-of-the-art UF pre-treated RO at normal flux (25 L/m2.h) (1.21 €/m3). The cost difference in financial space provides an opportunity to develop minimal pre-treated RO systems with improved control of membrane fouling and spacer clogging.

Clogging rate of pressure compensating emitters in irrigation with rainbow trout fish farm effluent

One of the most fertilizing effluents for irrigation are those from fish farms. In drip irrigation systems, emitter clogging is the biggest problem of the effluent application. Therefore, the aim of this paper was to assess the clogging rate of a drip irrigation system using the effluent of a rainbow trout farm. A control treatment with the input fish farm freshwater and two more using fish farm effluent, with and without irrigation lateral drainage, were tested. Pressure compensating emitters Microflapper with nominal discharges of 4 and 8 L/h (M4, M8) and Netafim with discharges of 4, 8, and 12 L/h (N4, N8, and N12) were used. For each treatment, 42 irrigations events were carried out with a total of 336 h over a 4-month period. Each irrigation event lasted 8 h every 3 days. Clogging rate, Christiansen uniformity (CU) and emission uniformity (EU) coefficients were utilized for assessing the hydraulic performance of emitters. There was no emitter completely clogged during the experiment. However, as the clogging rate gradually increased, lateral discharges during the irrigation season decreased to a maximum of 57% of the initial value in some laterals. Evolution of the clogging rate was unstable, especially in the control treatment. N4 emitter show the best performance regardless of the quality of irrigation water. The clogging rates of M4 and N8 emitters were significantly (p < 0.05) higher when effluent was used. The N12 and M8 emitters had the highest sensitivity to clogging, without differences between treatments. Results show the dependence of clogging rate on emitter type and its discharge. The CU as well as EU for all emitters and treatments were higher than the allowable minimum. Lateral drainage had the greatest impact on the N12 and M8 emitters, which had the highest discharge. Moreover, some relationships between CU and clogging rate were obtained. It is generally possible to use the rainbow trout effluent in a drip irrigation system with pressure compensating emitters.