Detention Time Research Articles

Hydraulic Design Concept of 6.60MLD Water Treatment Plant

Abstract: The design and construction of a 6.6 million liters per day (MLD) water treatment plant (WTP) in Belpada Village, Odisha, aim to meet the increasing water demand while ensuring public health through effective water treatment processes. The plant, which sources raw water from the Tel River, follows a well-structured treatment process that includes aeration, sedimentation, filtration, and disinfection. This journal outlines the hydraulic design, treatment schemes, and structural components of the WTP. Design calculations, based on CPHEEO standards, are also discussed, focusing on the hydraulic detention times, surface loading, filtration rates, and sludge management techniques.The design of water treatment plants (WTPs) plays a crucial role in delivering safe drinking water, especially in areas with high population density and industrial growth. The 6.6 MLD WTP designed for Belpada Village in Balangir District draws water from Tel River and utilizes a cascade aeration system for the removal of contaminants. This paper discusses the hydraulic and process design, focusing on flow rates, detention times, and surface loading parameters that meet the Central Public Health and Environmental Engineering Organization (CPHEEO) standards.

Efficiency of Canna indica, Phragmites australis and Eichhornia crassipes in Remediation of Leachate Through a Vertical Flow Constructed Wetland

Leachate treatment and disposal from landfills is one of major environment concern. Leachate contains various pollutants which may cause various environmental and health problem to terrestrial and aquatic living bodies. In the Present study, Landfill leachate was collected from Okhla landfill, New Delhi and treatment of leachate was done by using laboratory scale vertical flow treatment grown with Canna indica, Phragmites australis and Eichhornia crassipes, respectively. The experimental plots were obtained by set up of four different flow rates by balancing the inflow manipulations to obtain detention times of 1,7,14 for 21 days. The reduction of COD, BOD, NH4-N, TSS and heavy metals (Cd, Cu, Co, Cr, As, Pb, Ni, Fe, Zn and V) were investigated for 21 days. Average removal efficiency (%) for VCW (W1) planted with Canna indica showed 77.7%, 78.7%, 63.6%, and 76.7% for COD, BOD, NH4-N and TSS, respectively. Heavy metal removal (%) efficiencies of W1 planted with Canna indica was 60%, 82.5%, 100%, 29.37%, 27.9%, 62.67%, 13.33%, 44.5%, 75.2% and 78.85% for As, Cr, Cd, Cu, Co, Fe, Mn, Pb, Zn and V, in given order. VCW(W2) planted with Eicchornia crassipes species has shown reduction efficiency (%) of COD (68.5%), BOD (52%), NH4-N (45.4%), TSS (92.75%), respectively and in case of heavy metal 89.9% Cr, 100% Cd, 53.49% Cu, 62.7% Co, 85.2% Fe, 67.9% Ni, 76.2% Pb, 83.08% Zn, 65% As and 61.15% V, respectively. VCW (W3) planted with Phragmites australis exhibited removal efficiency (%) of COD (68.5%), BOD (52%), NH4-N (45.4%) and TSS (92.7%), respectively. Phragmites australis was able to remove As (100%), Cd (100%), Cr (89.9%), Cu (53.49%), Co (62.7%), Fe (85.82%), Ni (67.9%), Pb (76.2%), V (61.15%) and Zn (83.08%), respectively. All the three species were able to remove Cd (100 %). However, Canna indica (W1) has highest removal efficiencies (%) of COD (77.7%), BOD (78.7%) and NH4-N (63.6 %), respectively. Eicchornia crassipes has highest reduction efficiency (%) of TSS (92.75%), Cr (89.9%), Cd (100%), Cu (53.49%), Co (62.7%), Fe (85.2%), Ni (67.9%), Pb (76.2%) and Zn (83.08%), respectively. Phragmites australis was found good for removal of As (100 %) and Cd (100%). The result highlighted that these plant species can be used as single in lab scale Constructed wetland for the treatment Organic pollutants and heavy metals from landfill leachate.

A predictive fuzzy logic and rule-based control approach for practical real-time operation of urban stormwater storage system

Predictive real-time control (RTC) strategies are usually more effective than reactive strategies for the intelligent management of urban stormwater storage systems. However, it remains a challenge to ensure the practicality of RTC strategies that use accessible, non-idealized predictive information while improving their efficiency for successive rainfall events instead of specific phases. This study developed a predictive fuzzy logic and rule-based control (PFL-RBC) approach to address the continuous control of individual storage systems. This approach incorporates total rainfall depth forecast information with an intra-storm fuzzy logic system to optimize peak flow control and several rule-based strategies for pre-storm water detention, reuse, and release control. Computational experiments were conducted using a storage tank case study to test the proposed approach under various rainfall conditions and storage sizes. The results showed that PFL-RBC outperformed static rule-based control in infrequent design storms and realistic continuous rainfall events, reducing flood peaks and volumes by 55 %∼87 % and 7 %∼20 %, respectively, and significantly increasing water detention time and reuse volume. Meanwhile, PFL-RBC required less predictive information to achieve a 6 %∼15 % advantage in peak flow control compared to optimized model predictive control. More importantly, PFL-RBC was reliable in the face of input uncertainty, with <25 % performance loss for water quantity control when the realistic forecast error ranged from -50 % to +50 %. These findings suggest that the proposed approach has great potential to enhance the efficiency and practicality of stormwater storage operations.

Effectiveness of Eco Enzymes in Reducing Chemical Parameters of Tofu Factory Liquid Waste in Klumutan Village, Saradan District

The tofu industry generates substantial liquid waste that poses environmental challenges due to its high chemical oxygen demand (COD), total suspended solids (TSS), and pH levels. This study aimed to determine the effectiveness of Eco Enzymes in reducing these chemical parameters in the tofu industry waste in Klumutan Village, Saradan District. Utilizing a Quasi-Experimental method, the research employed purposive sampling of liquid waste from tofu production. The findings revealed that the application of Ecoenzyme at doses of 5%, 10%, and 15%, with detention times of 10, 15, and 20 days, significantly reduced COD, TSS, and pH levels. The results showed that both the dosage and detention time had a substantial impact on the effectiveness of Ecoenzyme in treating the waste. The implications of this study suggest that Eco Enzymes can be an effective, eco-friendly solution for improving wastewater management in the tofu industry, thereby contributing to environmental sustainability.

Real-time regulation of detention ponds via feedback control: Balancing flood mitigation and water quality

Detention ponds can mitigate flooding and improve water quality by allowing the settlement of pollutants. Typically, they are operated with fully open orifices and weirs (i.e., passive control). Active controls can improve the performance of these systems: orifices can be retrofitted with controlled valves, and spillways can have controllable gates. The real-time optimal operation of its hydraulic devices can be achieved with techniques such as Model Predictive Control (MPC). A distributed quasi-2D hydrologic-hydrodynamic coupled with a reservoir flood routing model is developed and integrated with an MPC algorithm to estimate the operation of valves and movable gates in real-time. The control optimization problem is adapted to switch from a flood-related algorithm focusing on mitigating floods to a heuristic objective function that aims to increase the detention time when no inflow hydrographs are predicted. The case studies show the potential results of applying the methods developed in a catchment in Sao Paulo, Brazil. The performance of MPC compared to alternatives that do not change the operation over time with either fully or partially open valves and gates are tested. Comparisons with HEC-RAS 2D indicate volume and peak flow errors of approximately 1.4% and 0.91% for the watershed module. Simulating two consecutive 10-year storms shows that the MPC strategy can achieve peak flow reductions of 79%. In contrast, the passive scenario has nearly half of the performance (41%). A 1-year continuous simulation results show that the passive scenario with 25% of the valves opened can treat 12% more runoff compared to the developed MPC approach, with an average detention time of approximately 6 h. For the MPC approach, the average detention time is nearly 14 h, indicating that both control techniques can treat similar volumes; however, the proxy water quality for the MPC approach is enhanced due to the longer detention times achieved.

Optimization of calcined eggshell as an effective coagulant for treating colloidal particles in complex effluents in the CPCP industry: mechanistic insights, scale-up design, and comparative analysis with alum

Highly turbid industrial effluent poses significant challenges to environmental sustainability. In this study, we investigated the optimal aggregation kinetics for the removal of colloidal and turbid particles in Cosmetics and Personal Care Products (CPCP) industrial effluent using calcined eggshell (CES) and industrial-grade aluminum sulfate as flocculants. The effluent characteristics were determined following ASTM specifications, and process optimization was carried out using a response surface design approach. The optimal operating conditions at a settling time of 3 min were found to be pH 8, 0.2 g/L dosage of CES, pH 10, and 0.3 g/L of alum dosage. The flocculation efficiencies of CES and alum were found to be 80% and 78%, respectively, demonstrating the effectiveness of both flocculants in removing colloidal particles and reducing turbidity in CPCP effluent. Mechanistic studies revealed that CES achieved particle removal through enmeshment and inter-particle bridging with a significant aggregation rate (1.3 × 10−7) and a lower floc breakup tendency (2.8 × 10−14) compared to alum-sweep flocculation. The hydrodynamics at a velocity gradient of 269s−1 ≤ G ≤ 29s−1 indicated spontaneous agglomeration within a flocculation period of ≤10 min, indicating rapid and efficient particle removal. The findings of this study justify the use of CES as a sustainable and effective option for the removal of colloid/turbid particles from CPCP effluent. The optimized operating conditions and mechanistic insights into the flocculation process contribute to establishing an optimized sedimentation geometry, with specified aspect ratio, detention time, hypothetical settling, and sludge depth for CES, ensuring the favorable stability of the finished CPCP effluent before discharge.

Evaluating the potential for denitrification in permeable interlocking concrete pavements

This research explored the denitrification potential of a submerged zone incorporated into the present permeable interlocking concrete pavement (PICP) design. The following three main factors controlling denitrification were investigated through a laboratory study: (i) detention time, (ii) inclusion of a carbon source (newspaper), and (iii) submerged zone depth. The study used 10 columns, each fully packed with 50–63 mm washed aggregate and including a 1.5 m deep submerged zone. Columns were paired according to detention time (1, 2, 5, 10 and ‘varied’ days) with one set including newspaper, the other set not. All columns were loaded with synthetic stormwater over a 4-month period. Samples were taken from different submerged depths (0, 300, 600, 900, 1200 and 1 500 mm) and analysed for concentrations of ammonia (NH3), nitrate (NO3−) and phosphate (PO43−) every 10 days. This study found that 10 – or more – days detention and the provision of a carbon source had the most significant impact on denitrification – providing an overall mean NO3− and nitrogen removal above 41% and 59%, respectively. Moreover, a submerged depth of 300 mm was sufficient to achieve a minimum NO3− removal of 41% in columns which included a carbon source and had 10 days detention. Generally, an increase in detention time resulted in an increase in NH3 and PO43− removal with overall mean values of 86% and 30%, respectively, achieved with 10−day detention periods.

Effectiveness of stormwater control measures in protecting stream channel stability

AbstractWhile research on the hydrologic impact of different types of stormwater control measures (SCMs) is extensive, little research exists linking urbanization, widespread implementation of SCMs and channel stability in headwater streams. This study evaluated whether the unified stormwater sizing criteria (USSC) regulations in the state of Maryland, USA, which require the use of both end‐of‐pipe and distributed, small‐scale SCMs, protect channel stability. To achieve this goal, a coupled hierarchical modelling approach utilizing the Storm Water Management Model (SWMM) and the Hydrologic Engineering Center River Analysis System 6.3 (HEC‐RAS) was developed to predict changes in streamflow and sediment transport dynamics in a first‐order gravel‐bed, riffle‐pool channel. Storm event discretization revealed that 88% of observed storm events during the 16 years (2004–2020) had durations less than 18 h and that the greatest peak flows resulted from storm events with durations less than 24 h. HEC‐RAS simulation results also showed that both channel degradation and aggradation, as high as 1.2 m, will likely occur due to regulations which require the use of 24 h duration design storms with a target stormwater detention time rather than bed material sediment transport limits. Overall, this study provides valuable insights into the complex interactions between SCM practises, flow regimes and sediment transport dynamics in heavily urbanized watersheds. It is recommended that SCMs be designed using a continuous simulation model with at least 10 years of continuous rainfall data. Furthermore, to protect channel stability, the SCM design goal should focus on maintaining pre‐development sediment transport regimes across a range of flows.

A partial siphon operational strategy strengthens nitrogen removal performance in partially saturated vertical flow constructed wetlands

The carbon‒oxygen balance has always been problematic in constructed wetlands (CWs), putting pressure on stable and efficient nitrogen removal. In this study, a novel partial siphon operational strategy was developed to further optimize the carbon and oxygen distributions of a partially saturated vertical flow CW (SVFCW) to enhance nitrogen removal. The removal performances of the partial siphon SVFCW (S-SVFCW) were monitored and compared with those of the SVFCWs at different partial siphon depths (15 cm, 25 cm and 35 cm) in both the warm and cold seasons. The results showed that the partial siphon operating strategy significantly facilitated the removal of ammonia and total nitrogen (TN) in both the warm and cold seasons. When the partial siphon depth was 25 cm, the S-SVFCWs had the highest TN removal efficiency in both the warm (71%) and cold (56%) seasons, with an average improvement of 46% and 52%, respectively, compared with those of the SVFCWs. The oxidation‒reduction potential (ORP) results indicated that richer OPR environments and longer hydraulic detention times were obtained in the S-SVFCWs, which enriched the denitrification bacteria. Microbial analysis revealed greater nitrification and denitrification potentials in the unsaturated zone with enriched functional genes (e.g., amo_AOA, amo_AOB, nxrA and nirK), which are related to nitrification and denitrification processes. Moreover, the strengthening mechanism was the intensified oxygen supply and carbon utilization efficiency based on the cyclic nitrogen profile analysis. This study provides a novel partial siphon operational strategy for enhancing the nitrogen removal capacity of SVFCWs without additional energy or land requirements.

Unlocking potential: Exploring the methane production potential in anaerobic co-digestion of cassava wastewater and glycerol

This study aimed at evaluating the feasibility of CH4 production in a mesophilic (30 °C) single-stage anaerobic co-digestion of cassava wastewater (CW) and glycerol in an anaerobic fluidized bed reactor (AFBR) with mixing ratio of 50 % / 50 % CW/Gly on a (chemical oxygen demand)COD basis. Thus, the following strategy was used: increasing the organic loading rate (OLR) (1–20 g COD.L−1.d−1) by increasing the substrate concentration (1–20 g COD.L−1) and applying a hydraulic detention time (HRT) of 24 h. The AFBR presented a maximum methane (CH4) content of 88.38±1.94 % and a CH4 yield (MY) of 293.48±18.37 mL of CH4.mL−1CODrem in the OLR of 1 g COD.L−1.d−1 and the maximum methane production rate (MPR) of 62.09±2.75 mL of CH4.L−1.h−1 in the OLR of 20 g COD.L−1.d−1. The conversion of glycerol and carbohydrates remained above 91±0.54 % and 82±2.79 %, respectively, and the COD conversion was above 80±0.65 %. The main metabolites were HAc, HPr, HBu, EtOH and HVa. The most abundant genera identified in the AFBR were Izemoplasmatales and Enterobacteriaceae for the bacteria domain, and Methanosaeta, Methanobacterium for the archaea domain. The single-stage system is robust and can operate with higher OLR without reducing the efficiency of wastewater treatment and CH4 production.

Speed-dependent bacterial surface swimming.

In the early phase of biofilm formation, bacteria identify surfaces and increase the intracellular level of the second messenger c-di-GMP, resulting in a decrease in swimming speed. Here, we utilized advanced microscopy techniques to investigate the impact of swimming speed on bacterial surface swimming, focusing on Escherichia coli and Pseudomonas aeruginosa. We found that an increase in swimming speed led to an increase in the radius of curvature and a decrease in surface detention time. These effects were explained through hydrodynamic modeling as a result of an increase in the cell-surface distance with increasing swimming speed. We also observed distinct surface-escaping mechanisms between the two bacterial species. Our study suggests that a decrease in swimming speed could enhance the likelihood of cells adhering to the surface, promoting biofilm formation. This sheds light on the role of reduced swimming speed in the transition from motile to sedentary bacterial lifestyles.

Ensuring Legal Safeguards: Defendant Protection When Detained Beyond Time Limits

Criminal law intricately intertwines with everyday life, regulating behaviors, subjects liable for punishment, and corresponding sanctions. This study employs normative research methods, analyzing literature and case studies to investigate violations within the criminal justice system, particularly concerning detention time limits. By scrutinizing legal statutes, theories, and precedents, this research unveils instances where defendants are deprived of their rights through unjustified extensions of detention beyond prescribed limits. The findings underscore the importance of upholding legal safeguards and the implications of disregarding procedural fairness in criminal proceedings. Highlights : The study elucidates the intersection of criminal law with everyday life, emphasizing regulations governing detention time limits. It underscores the significance of upholding procedural fairness in criminal proceedings to prevent legal injustices. Utilizing normative research methods, the research unveils instances of unjustified extensions of detention, highlighting the need for adherence to legal safeguards. Keywords: Criminal law, Detention time limits, Legal injustices, Procedural fairness, Normative research

Application of a generalized hybrid machine learning model for the prediction of H2S and VOCs removal in a compact trickle bed bioreactor (CTBB)

This study presents a generalized hybrid model for predicting H2S and VOCs removal efficiency using a machine learning model: K–NN (K - nearest neighbors) and RF (random forest). The approach adopted in this study enabled the (i) identification of odor removal efficiency (K) using a classification model, and (ii) prediction of K <100%, based on inlet concentration, time of day, pH and retention time. Global sensitivity analysis (GSA) was used to test the relationships between the inputs and outputs of the K-NN model. The results from classification model simulation showed high goodness of fit for the classification models to predict the removal of H2S and VOCs (SPEC = 0.94–0.99, SENS = 0.96–0.99). It was shown that the hybrid K-NN model applied for the “Klimzowiec” WWTP, including the pilot plant, can also be applied to the “Urbanowice” WWTP. The hybrid machine learning model enables the development of a universal system for monitoring the removal of H2S and VOCs from WWTP facilities.

Comparison of Under Water Wireless Communication Using Deep Learning

The challenges encountered in aquatic communication systems encompass colourful factors, including limited bandwidth, high energy consumption rates, extended propagation detention times, End- to- End Delay(E-ED), media access control, routing complications, resource application, and power constraints. These challenges bear the perpetration of energy-effective protocols, which can be distributed into localization- grounded or localization-free protocols. This design primarily focuses on reviewing and assaying localization-free protocols, considering environmental variables, data transmission rates, transmission effectiveness, energy consumption rates, E-ED, and propagation detainments. Through a comprehensive review, the design aims to identify the strengths and sins of being protocols, thereby paving the way for unborn advancements in Aquatic Wireless Sensor Networks (UWSNs). The proposed check entails an in- depth examination of localization-free protocols, pressing the specific problems addressed and the crucial parameters considered during routing in UWSNs. Unlike former checks, this study concentrates on the current state- of- the- art routing protocols, emphasizing the routing strategy issues they attack. By emphasizing the advantages of each protocol, the design seeks to decide energy-effective results. likewise, detailed descriptions of the routing strategies employed by each protocol are handed to enhance appreciation. also, the downsides of each protocol are strictly examined to grease farther disquisition and identify the most suitable protocol. The comprehensive analysis of routing strategies, along with the delineation of pros and cons, not only sheds light on being challenges but also offers precious perceptivity into unborn exploration directions. By presenting open challenges and delineating implicit exploration avenues, this design aims to contribute to the ongoing elaboration and enhancement of aquatic communication systems.

The Domestic Wastewater Treatment Installation's Performance Study of Technical Aspects in Cahaya Abadi Housing, Palembang City

&lt;p&gt;&lt;em&gt;The comprehensive treatment of rural water pollution was pioneered by developed countries, and many nations now have a variety of sewage treatment facilities and process technology that are suitable for their rural features. Domestic sewage is handled differently at sewage treatment facilities in cities than it is in rural areas. Its distributed drainage sites make it difficult to collect. The Indonesian government is implementing domestic wastewater treatment (DWWT) to reduce water pollution in areas without separate residential waste processing. The results of this analysis show that an extensive amount of maintenance is needed to ensure that the DWWT and its distribution system run as efficiently as possible. The Cahaya Abadi Housing in Sri Mulya Village, Sematang Borang District, Palembang City, is where the study is being carried out. DWWT Cahaya Abadi processes domestic liquid waste from household activities, although even though the facility has room for 169 dwellings, only 31 homes use it. As a result, capacity is not being used. The results of identifying the technical factors show that the use of pumps results in differences in flow discharge that affect the outcomes of the DWWT output. The extremely rapid pump that is being used has an impact on the processing process and the current detention time.&lt;/em&gt;&lt;/p&gt;

EFFECT OF DETENTION TIME IN REDUCING FE AND MN CONCENTRATION OF GROUNDWATER: CASE STUDY AT THE UNIVERSITAS NEGERI MALANG

Groundwater is a natural resource used by humans to fulfil their living needs which should meet the Republik Indonesia Minister of Health Regulation No. 2/2023. Aim: This research aims to contribute to solve these challenges and meet the clean water quality standard. Methodology and Results: The groundwater sample was taken from the deep well of Al-Hikmah Mosque, Universitas Negeri Malang (UM). It was indicated to contain Fe and Mn, as evidenced by its yellowish colour when left undisturbed for some time. A laboratory-scale experiment was conducted for the deep well treatment and analysis. The treatment system consists of aeration, sedimentation, and filtration. The filtration unit comprises several natural media such as gravel, silica sand, zeolite, and activated charcoal. This experiment used detention times of 120 and 240 minutes as dependent variables. Conclusion, significance, and impact study: The results showed that detention times of 120 and 240 min have efficiency on turbidity reduction of 92.86% and 98.69%, Total Dissolved Solids (TDS) of 10.42% and 14.47%, Fe of 23.01%, Mn of 62.39% and 94.70%, and for CaCO3 of 2.98% and 11.17%, respectively. The research findings demonstrated that a detention time of 240 min generated water quality that met the Minister of Health No. 2/2023 standards. Detention times of 120 minutes and 240 minutes led to significant differences in water quality concerning temperature and CaCO3. The filtration system with a detention time of 240 minutes can be considered as an alternative groundwater treatment solution for the deep well of Al-Hikmah Mosque, Universitas Negeri Malang.

Helically Coiled Tube Flocculators in Water Clarification Systems: Optimal Length Evaluation and Process Efficiency Probabilistic Analysis

New sustainable technologies have been explored as potential solutions to address the global issue of water scarcity by enhancing water treatment processes. In this context, an innovative coagulation/flocculation unit known as the helically coiled tube flocculator (HCTF) has emerged, offering notable advantages such as high process efficiency, short detention time, and cost-effectiveness compared to conventional hydraulic units. The HCTF harnesses its flow energy to disperse coagulation/flocculation agents and facilitate the formation of flocs through collisions between destabilized particles. This paper introduces an assessment of the process efficiency, geometric properties, and hydraulic characteristics of an alternative and sustainable water clarification system incorporating an HCTF, with the aim of determining its optimal length. In HCTFs, the flocculator’s length (referred to as L) can exert a significant influence on process efficiency, necessitating a comprehensive evaluation of this parameter for the rational design of such units. To accomplish this, the paper scrutinizes physical experimental findings from previous research articles, which are related to the efficiency of flocculation (indirectly estimated by analyzing turbidity removal efficiency). Additionally, it examines the geometric and hydraulic attributes across 48 distinct variations of HCTFs. This study culminates in the development of a model for determining the optimal length for HCTFs. Furthermore, it includes a probabilistic assessment that establishes a connection between the optimal length and other parameters involved in the clarification process—whether deterministic or probabilistic—and their impact on the final process efficiency, all with a 90% confidence level. This paper stands out by pioneering the determination of the optimal length of HCTFs, filling a gap in the existing literature, which previously only mentioned the importance of this parameter in process efficiency without providing a predictive model. The results highlight the robustness of the proposed alternative clarification system. Even in scenarios with substantial variations in dimensional hydraulic parameters (such as a worst-case relative standard deviation of 20%), the process efficiency fluctuations range between 1.3% and 5.2%. These outcomes lend support to the adoption of such alternative water clarification systems. They also underscore the potential of probabilistic evaluation as a valuable tool for investigating novel water and wastewater treatment units and enhancing existing ones.

Application of a simplified model for assessing particle removal in dissolved air flotation (DAF) systems: Experimental verification at laboratory and full-scale level

Particle-bubble collisions in dissolved air flotation (DAF) systems play a crucial role in the removal of total suspended solids (TSS). DAF particle-bubble collision models incorporate factors such as particle diameters, charge and density, bubble diameters, and collision factors. The challenge lies in accounting for the wide range of particle and bubble sizes and obtaining complex model inputs. To address this, a simplified model for TSS removal in DAF units was established using low-cost laboratory measurements, including particle size distribution and density. Additionally, microbubble diameter profiles were derived from bubble velocities using particle image velocimetry software (PIV). Six independent variables, encompassing influent particle characteristics (such as particle size distribution and density) and DAF running characteristics (temperature, contact zone detention time, inflow and recycle flows), were employed in the simplified model. The model's accuracy was evaluated using a laboratory-scale DAF system with two different influents: Delft canal water and anaerobic sludge. The predicted TSS removal from the simplified model aligned well with the laboratory-scale DAF results, yielding removal efficiencies of 68 ± 1 % and 77 ± 3 % for Delft canal water and anaerobic sludge, respectively. Furthermore, when the simplified model was applied to two full-scale DAF systems, it successfully identified an underperforming system (DAF2) with a TSS removal efficiency of 91 %, contrasting with the theoretical removal model-predicted efficiency of 98 %. This study highlights the utility of combining bubble size distribution measured by PIVlab and particle size distribution obtained using FIJI-ImageJ as an economical and efficient approach to acquiring the necessary inputs for predicting TSS removal in DAF systems.

Field Approach on the Effectiveness of Hydraulic Flocculator Followed By Sedimentation and Rapid Sand Filter

This research investigates the effectiveness of a hydraulic flocculator at the Kalanki Groundwater Treatment Project-Sipradi in Kalanki-Kathmandu. Hydraulic flocculation is a cost-effective alternative to mechanical flocculation, particularly beneficial for developing nations. The study involved determining the optimal Poly Aluminium Chloride (PACl) dosage through Jar Testing and assessing the flocculator's efficiency in the field with this dose. The research also analyzed other treatment units under various PACl doses to evaluate the Water Treatment Plant's operational conditions and the required PACl dose for efficient turbidity removal. The system included components like a deep well source, V-Notch weir tank, hydraulic flocculator, sedimentation tank, rapid sand filter (RSF), chlorinator, and clear water reservoir, with a 16-minute flocculator detention time. Baffle walls were strategically positioned at various intervals on-site. The study revealed that while sedimentation with coagulation achieved peak efficiency at a PACl dose of 80mg/l, it was less efficient than a 16-minute jar detention, likely due to sedimentation tank short-circuiting. Increasing the PACl dose from 20 mg/l to 80 mg/l improved overall unit efficiency, indicating the need for more mixing energy in the existing flocculator length for optimal results. The filter unit's efficiency remained consistent, whether with or without coagulation, at 57.69% and 54.10%, respectively. These results emphasize the importance of further investigation to enhance water treatment processes and coagulant dosages for improved effectiveness in this critical field.

The Use of Intraosseous Infusion in the Early Resuscitation of Patients With Extremely Severe Burns.

According to research, shock, the most common complication of extremely severe burns, is also the leading cause of mortality among patients with such burns. The case fatality rate reaches 83.45% when the total burn area exceeds 90%. The American Heart Association in 2020 recommended the intraosseous (IO) access after the peripheral access and prior to the central venous access when venous cannulation is either difficult or delayed. The use and experience with intraosseous infusion in extremely severe burns are still limited. We report efficacy and safety results from 19 burn patients treated with IO infusion between June 2020 and December 2022. In these patients, the mean injury time of burns was 1.55 ± 1.10 hours, the mean burn surface area was 86.24% ± 11.33%, the mean catheterization time was 49.68 ± 10.11 seconds, and the mean emergency retention time was 2.75 ± 1.74 hours, the mean actual fluid supplement amount was 5,533.68 ± 3,077.19 mL, the mean hourly urine volume of the patient was 93.31 ± 60.94 mL, the mean emergency detention time was 4.16 ± 2.97 hours, and the mean duration of hospitalization was 34.50 ± 25.38 days. The results demonstrated a clinically meaningful improvement and higher response rate vs peripheral venous cannulation and an acceptable safety profile in those patients.