Utilizing the waterworks sludge byproduct in the treatment of wastewater contained methylene blue dye is one approach that has been taken in an effort to lessen the difficulties that are associated ...with managing such byproduct. The prime aim of this work is manufacturing of novel sorbent from co-precipitation of magnesium oxide nanoparticles on the surfaces of waterworks sludge in the existence of cetyl trimethyl ammonium bromide surfactant. Surfactant 0.04 g/50 mL, dose of sludge 2 g/50 mL, and pH 12 were the most efficient preparation parameters to remove 75.31% of adopted dye. The adsorption studies were conducted under various conditions of contact time (0–240 min), concentration of dye (10–300 mg/L), sorbent mass (0.05–1.5 g), and solution pH (3–12). The best values of batch parameters were identical to the highest percentages of contaminant removal. Results proved that the magnesium oxide nanoparticles are attached to the sludge surfaces. Freundlich and pseudo-second-order models have perfectly described sorption results with 59.92 mg/g maximum sorption capacity. The breakthrough curves can be accurately described by the Bohart-Adams model. The outputs of continuous tests have been paved the way for future usage of the prepared sorbent in the field permeable reactive barrier technology.
Modelling Stilling Basins for Sewage Networks Mohammed, Shahad R.; Nile, Basim K.; Hassan, Waqed H.
IOP conference series. Materials Science and Engineering,
01/2020, Volume:
671, Issue:
1
Journal Article
Peer reviewed
Open access
Concrete elements play an effective role in stilling basin design in terms of enhancing the dissipation of energy to prevent immoderate scouring of downstream structures. Proper appurtenances, such ...as wedge-shaped splitter blocks, baffle walls, inverted t-sections, rectangular walls, inverted L sections, and impact walls, are thus utilised with circular pipe outlets to create stilling basins that are shorter yet more effective, and thus more economical. This research was based on numerical analysis of stilling basins using FLOW-3D software; the resulting Froude numbers were compared with the Froude number of a case study, a stilling basin manhole created by the Karbala Government. This research thus examined the influence of Froude number, the arrangement and location of dissipators, and the height of the pipe inlet under different hydraulic condition in order to better simulate stilling basin models. The turbulent energy dissipation was found to vary from 16% to 85%. The results from the models showed that L-sections offered maximum turbulent energy dissipation (ΔE/E1), while the rectangular wall shape gave minimum turbulent energy dissipation (ΔE/E1). It was also observed that the maximum turbulent kinetic energy almost always occurred in the initial sections, with flow becoming generally less turbulent at the end sections. Thus, at the end of all stilling basins, the turbulent kinetic energy dissipation and turbulent kinetic energy profiles became more uniform. The proposed numerical simulation using FLOW-3D was shown to be a reliable tool for predicting and discussing the turbulent energy dissipation in stilling basins. Further conclusions included the fact that the maximum turbulent energy dissipation (ΔE/E1) increases as values of Fr increase. The results of this research could thus help hydraulic designers to consider their selections for the optimum design of stilling basins more carefully.
Climate change is becoming a leading issue in the 21st century due to its devastating environmental and socioeconomic impacts. It is believed to have significant impacts on the water resources and ...groundwater in the Middle East region, especially in Iraq. In this study, three different global climate models, under the 6th IPCC report, were downscaled under two SSPs scenarios in the middle and west of Iraq. The downscaled models were fixed for bias using CMhyd (climate model data for hydrologic modeling) over the study area. This was achieved using data from four locally chosen weather stations from 1983 to 2022. Three CMIP6 global models were considered and compared. These were the Australian Community Climate and Earth-System Simulator version 1 (ACCESS-CM2), the Beijing Climate Center Climate System Model version 2 (BCC-CSM2-MR), and the sixth version of the Model for Interdisciplinary Research on Climate (MIROC6).The findings of this study show that the temperature and precipitation changes in the three models under two scenarios in the future period (2023–2050) show an increasing trend compared to the observation period (1983–2014). The results of the generated predictions show that there will be an increase in annual maximum temperatures by this century's end, by 1.26–2.08 °C under scenario SSP2–4.5 and 1.57–2.34 °C under scenario SSP5–8.5 across all study stations. The study found that the annual increase in precipitation over the observed period varies between scenarios (SSP2–4.5 and SSP5–8.5), ranging from +3.56 to +3.87% for SSP2–4.5 and + 7.22% to +12.61% for SSP5–8.5. The results should help improve our understanding of the effects of climate change on the study region and encourage planners and stakeholders to identify optimal strategies for mitigating them.
•CMIP6 datasets were used to project future climate change for the first time in the study area.•CMhyd is an effective method for bias correction of precipitation and temperature data.•The projected increase in annual temperatures by this century's end is 1.57–2.34 °C.•Precipitation is projected to increase from 3.56 to 12.61% for the years 2023–2050.•The ACCESS-CM2 projected a higher increase in precipitation and temperature compared with the other GCMs.
Numerous natural and artificial streams, including those for irrigation ditches, wastewater treatment facilities, and conveyance structures for fish movement, have open channel confluences. The flow ...dynamics at and around the junction are intricate; in particular, immediately downstream of the junction, the flow creates a zone of separation on the inner wall along with secondary recirculation patterns. The structure of this complicated flow depends on several factors, including the flow rates in both channels, the angle of confluence, the geometry of the channels, including the longitudinal slope and bed discordance, the roughness of the boundary, and the intensity of the turbulence. It also has a significant impact on bed erosion, bank scouring, etc. The objective of the current work is to calculate the velocity profile and the separation zone dimensions for four angles (30o, 45o, 60o, and 75o) through the simulation process, and the best angle using a three-dimensional model. This work gives a detailed application of the numerical solution (Finite Volume) via Flow 3D software. Results for two flow discharge ratios, q*=0.250 and q*=0.750 were shown; the numerical model and the experimental results agreed well. The findings are consistent with past research and demonstrate how the main channel flow pattern is affected by changes in the channel crossing angle, as well as how greater separation zones are produced in the main channel when the flow discharge ratio q* (main channel flow divided by total flow) is smaller. Analysis revealed that the separation zone's smallest diameter will be at the 75ocrossing angle. Doi: 10.28991/CEJ-2023-09-05-07 Full Text: PDF
The management of rainwater collection in a practical way is a fundamental need for the management of water resources in a manner that is sustainable. The goal of this research is to determine ...whether or not remote sensing technology is effective in providing data on precipitation for the purpose of locating rainwater collection tank locations in the province of Karbala. Rainfall patterns fluctuate considerably. Remote sensing may not capture variability enough to estimate the rainfall period and location. Sustainable rainfall harvesting requires accurate rainfall timing and distribution. This information is applied in the modeling of hydrological processes, the management of disasters, and environmental research. Following the completion of a geographical study, it has been established that the city of Karbala may be divided into two basic sections. Through the use of estimation, it is possible to more easily identify the region that is ideal for the location of rainwater-harvesting reservoirs and lakes. On the contrary, it is crucial to keep in mind that a location that was chosen based on average rainfall over a period of two years could not be suitable for other time periods. This is an idea that should be kept in mind several times. To put this into perspective, when choosing a location, it is vital to take into consideration the severity of the rainfall as well as the geographical location of the area. Particularly in locations such as Karbala, the implementation of data visualization systems into water management practices has the potential to improve both the efficiency and sustainability of water management methods. The findings of this study show the significance of implementing precise site selection techniques to enhance rainwater collection systems and encourage activities that are environmentally responsible for water management.
In arid and semi-arid countries like Iraq, which suffer from water scarcity due to the effects of climate change and decreased surface water flow, groundwater is considered a vital source of ...irrigation water. This study is concerned with the influence of artificial recharge on the rehabilitation of the unconfined aquifer called Al-Dibdibba, located between the cities of Najaf and Kerbala in central Iraq around 31°550′ N and 32°450′ N and 43°300′ E and 44°300′ E. Due to excessive groundwater pumping rates for irrigation, this aquifer has suffered from groundwater decline and increased salinization during the previous 20 years. By establishing a conceptual model in the groundwater modeling system software (GMS), a numerical model was made to simulate groundwater flow. Artificial recharge using recycled water (tertiary treatment) from Kerbala's primary WWTP was carried out using 25 injection wells. The model was calibrated against historical and observed water level data for periods from 2016 to 2017. Three scenarios to predict how the aquifer would act with artificial recharge of 5%, 8%, and 10% from the total daily outflow of the WWTP in Kerbala (100000 m3/day) were studied. The calibration model met the observed values of groundwater levels with R2 = 0.989 for steady-state simulations and R2 = 0.987 for transient simulations. In the final analysis of the simulation, the results show that the maximum predicted groundwater level was raised by the injection of treated water through 25 wells by 1.05 m for 5000 m3/day, 2 m for 8000 m3/day, and 3 m for 10,000 m3/day recharge pumping rates. In addition, if water were pumped into the aquifer, it might support the development of agricultural lands covering more than 93 km2. So, artificial recharge can be considered one of the important solutions to adaptation to the effects of climate change and desertification in Iraq. Doi: 10.28991/CEJ-2023-09-09-010 Full Text: PDF
Iraq is located in the Middle East, a climatic region distinguished by arid and semi-arid environments and which is expected being more susceptible to possible effects of global warming and climate ...change. In current research, a stochastic weather generator, LARS-WG 6.0, was utilized to simulate historical and projected future daily climatic data and the appropriateness of the model to project daily temperature and daily precipitation. Considering the enormous uncertainties associated with future climate projections, five general circulation models (GCMs), MIROC5, CanESM2, HadGEM2-ES, NorESM1-M, and CSIRO-Mk3.6.0, which represent the most suitable models for the region according to previous studies, were utilized to project the future climate depending on two important scenarios of emissions, RCP4.5 and RCP8.5, across the current century by three periods. The climate data from six meteorological stations located in Southern Iraq were used to validate the model, which was based on historical data spanning thirty years (1980–2010). According to the findings, the yearly maximum temperature will rise based on the generated predictions at the end of the twenty-first century by 1.32–3.94 °C under RCP4.5 and 1.50–5.92 °C under RCP8.5 for all stations studied. For precipitation, the model projections show that there are various trends over all the GCMs used. This denotes the high level of uncertainty of the precipitation prediction if applied to one model only, as some models, e.g., CanESM2, predict an increase in precipitation while other models, e.g., MIROC5, refer to a decreasing trend or no change in precipitation in the future. Changes in rainfall and temperature will have a big effect on how much water is available in the south of Iraq, especially in the marsh and agricultural areas, which will face desertification, water shortages, and other environmental problems.
•Five general circulation models (GCMs) were used to project the future climate in arid areas such as the Middle East.•Two emission scenarios, RCP4.5 and RCP8.5, over three selected time periods: 2021–2040, 2051–2070 and 2081–2100 were used.•The maximum temperatures and precipitation will be expected to affect by climate change and global warming.
Odors emanating from treatment plants are a source of concern for those working in these plants. Hydrogen sulfide gas is the most dangerous aromatic compound for WWTP workers and plant equipment and ...facilities. In this study, hydrogen sulfide gas was modeled using the TOXCHEM model of the Aoun sewage treatment plant, which operates with the MBBR system. The TOXCHEM model was calibrated and validated and the results were within the R and RMSE parameters. Sensitivity analysis was studied on the most important factors affecting the emission of hydrogen sulfide gas in the Aoun sewage treatment plant. The results showed that the most important processes that obtain hydrogen sulfide gas are biodegradation, absorption, emission or volatilization. The results in winter, (12 °C), and summer (35 °C) about 6% and 8%, 18% and 17%, 72% and 65%, 0% and 0%, and 4% and 10% were fated as emitted to air, sorbed to sludge, discharged with effluent, biodegraded, and treated with odor removal system, respectively. The highest emission of hydrogen sulfide gas was observed in the preliminary stage (lift station, course and fine screen, API, and equalization tank), especially in the API basin, where it reached 1.8 ppm. Increasing temperatures, the air flow rate, decreasing the value of pH, increasing the flow and increasing the filling time in the pumping station all cause an increase in the emission of hydrogen sulfide gas. Modeling hydrogen sulfide gas by TOXCHEM model gave an excellent prediction to control the emission of hydrogen sulfide gas for decision makers in the plant.
Iraq is located in a water-stressed area with little of its own water resources. This means that groundwater is one of the main water resources for this region, this true for other countries in the ...Middle East. The impact of global warming and climate change in the future, through increases in temperature and fluctuations in rainfall, will escalate water scarcity and the degradation of the quality of water across different water resources. In the current study, the impact of future global warming and climate change on groundwater natural recharge in an unconfined aquifer (Umm Er Radhuma), in the Western Desert of Iraq, was assessed using the simulation tool WetSpass. Future climatic parameters pertaining to the study area, were predicted by downscaling a General Circulation Model (GCM), the second Canadian Earth System Model (CanESM2). CanESM2 was applied to two expected emission representative concentration pathway scenarios; medium RCP4.5 and high RCP8.5, across a period spanning 2020 to 2099, in seven meteorological stations distributed throughout the study region. Based on the statistical indicators from the validation process, the downscaling modeling operation was deemed efficient at predicting climate parameters (average temperature, precipitation and wind speed) during the chosen period. The calibrated future simulations scenarios projected that precipitation will decrease by 9.2% and 14.1% for RCP4.5 and RCP8.5 emissions scenarios, respectively. The temperature will increase by 0.96 °C under RCP4.5 and 2.05 °C for RCP8.5. Annual groundwater recharge is predicted to decrease by 13.6% and 21.2%, under RCP4.5 and RCP8.5 emissions scenarios respectively, by the end of the present century.
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•For study area, climate change reduces the recharge of groundwater aquifers.•Statistical downscaling model is effective in the projection of climate parameters.•Average temperatures will continue to increase during the current century.•Precipitation rates will decrease in the studied area during the current century.
The effective and consistent operation of wastewater treatment plant systems (WWTPs) is crucial for the sustainability of the environment and public health protection. The main objective of the ...present study is concentrated on assessing the reliability of the Karbala wastewater treatment plant’s (WWTP’s) performance. It investigates the plant’s efficiency through the weekly concentration values of three key water quality indicators, which are biochemical oxygen demand (BOD), total suspended solids (TSS), and chemical oxygen demand (COD) collected over 4 years of operation from 2020 to 2023. The methods employed were the coefficient of reliability (COR) method for plant performance in removing the effluent concentrations of 5-day biochemical oxygen demand, COD, and TSS. The analysis found that the COR values were generally close to 1 for all years, with the lowest value recorded at 0.71 in 2020, during the initial stabilization phase of the WWTP. The main finding was that the Karbala WWTP has been effective in pollutant removal. The present study is important because it supplies dependable data that wastewater treatment operators can use to assess their daily operations and gauge the success of biological treatment methods. It is worth noting that no study has been done on the reliability model for examining the quality of wastewater of the Karbala WWTP, and such a method of analysis is considered a new improvement for the evaluation of the plant to meet the Iraqi standards.
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