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Surface heat exchange is essential in water quality modelling. It is necessary to provide water surface temperature data for determining the air-water heat fluxes. In this paper, air-water temperature relationship was developed statistically by using the non-linear logistic regression. The model outcome made water temperature easy to calculate depending on air temperature data, which is available from the close by weather stations. The regression development and analysis were performed based on meteorological and water temperature data measured at Laurance Lake, Oregon US. The air-water relationship impact on surface heat fluxes (short and long radiation, back radiation, evaporation, conduction) was used to evaluate the regression function goodness in conjugate with error statistics. Results showed that the regression can reproduce the total heat flux wave without curve shifting. For one-day computational time, MAE, RMSE, and NSE recorded 0.552, 6.936, and 0.902 Watt/m2, respectively using the logistic regression. The regression kept the same behaviour when running over longer period of time, matching the real total flux (When a maximum value of 774.21 Watt/m2 was estimated based on measured water temperature, the logistic modelling gave a value of 752.52 Watt/m2 corresponding to water temperature of 15.642 °C and 15.637 °C, respectively).

Since industrial and human activities have been developed, water quality intensely degrades in Hilla River, Iraq. Using remote sensing technology provides data for assessing and monitoring water quality in surface water bodies. Thus, in this study, Landsat 8 satellite images (2016 to 2021) were statistically tested for developing linear models capable of estimating water quality parameters in the river based on field data, including turbidity (turb), electric conductivity (EC), hydrogen ions (pH), total suspended solids (TSS), chloride ions (Cl), sulfate ions (SO4), Alkalinity (ALK), total hardness (TH), calcium (Ca), potassium (K), sodium (Na), magnesium (Mg), and total dissolved solids (TDS). The results showed that seven parameters have a significant relationship with the spectral bands ratio (p-value less than 0.05). Some of them (TDS, SO4, and ALK) are positively correlated with bands ratio (Band10/Band3, Band10/Band3 and Band10/Band4, and Band3/Band7), respectively. Others (Mg, Ca, TH and pH) are inversely correlated with (Band4/Band7, Band1/Band4, Band1/Band4, and Band1/Band2), respectively. However, K, Na, TDS, Cl, EC and turb have an insignificant correlation with any band ratio.

For the availability of drinking water, saline water treatment has become exceedingly necessary. The purpose of this research was to determine how efficient electrocoagulation (EC) with monopolar iron electrodes was for desalinating water from Iraq’s Sawa Lake. Absolute dissolved solids (TDS), chloride (Cl), bromine (Br), and sulfate (SO4) are some of the salty water forms that are being targeted. The impacts of five considerations on treatment efficiency were studied, including current (I), detention time (RT), pH, speed of mixing stirring (Mrpm), and inter-electrode distance (IED). I=0.8A, RT=80 minutes, pH=8, IED=1cm, and Mrpm=500 were found to be the best values. TDS, Cl, Br and SO4 removal efficiencies were 91 percent, 93 percent, 92 percent, and 90 percent, respectively, under ideal conditions. It can be inferred that the EC system used in this research was operative in removing salts from the water of Sawa lake.

In hot climates, achieving a good indoor environmental quality (IEQ) in existing buildings is important especially with climate change challenges as future heat waves will increase in frequency, duration, and intensity. In educational buildings, there is much more focus on the IEQ parameters and the interactions among them that need to be in line with the continuously changing learning environment. This study assesses the IEQ parameters (represented by noise, temperature and humidity) at three selected campus areas (lecture rooms of an administrative department building (LR), main hall of a management department building (MH) and a central library building (CL)) at the Al-Najaf Technical Institute (NTI), Al-Najaf City, Iraq, for the period from May to December 2019. A statistical analysis using a multi-linear regression model was performed to determine the relationship between the selected IEQ parameters and explain the noise level behavior as a function of the temperature and relative humidity. The research indicated that the noise levels and temperature values exceeded the maximum standard limits in all buildings reflecting the displeasing sound and heating quality within the studied areas, while the readings for relative humidity within each building environment complied with standards. Moreover, for both LR and MH buildings (R2 ≥ 0.8, significance F ≤ 0.01), the noise values were satisfactorily modeled by temperature and relative humidity highlighting the interactions between temperature, humidity and noise under consistent conditions. However, the results for the CL building (R2 = 0.6, significance F = 0.1) showed no relationship between the IEQ parameters, highlighting the fact that this building is exposed to unsteady conditions (an irregular number of people using this building during the daytime) resulting in a high variation of data measurements. The current results demonstrate that detailed modeling can be helpful to predict IEQ parameters depending on other known parameters in buildings. The results of the predictive model aligned with the directly measured data. Therefore, its performance is equally effective, but with a significant reduction in cost and time consumed.

In this work, landfill leachate treatment by electrocoagulation process with a novel rotating anode reactor was studied. The influence of rotating anode speed on the removal efficiency of chemical oxygen demand (COD), total dissolved solids (TDS), and total suspended solids (TSS) of raw landfill leachate was investigated. The influence of operating parameters like leachate pH, leachate temperature, current, and inter-distance between the cathode rings and anode impellers on the electrocoagulation performance were also investigated. The results revealed the optimum rotating speed is 150 rpm and increasing the rotating speed above this value led to reducing process performance. The leachate electrocoagulation treatment process favors the neutral medium and the treatment performance increases with increasing current intensity. Furthermore, the electrocoagulation treatment performance improves with increasing leachate temperature. However, the performance reduces with increasing inter-electrode distance.

In this work, the mass transfer of aluminum ions in the electrocoagulation reactor was investigated using limiting current density technique by employing a novel rotating impeller anode. The effect...

Imperon Violet KB dye is detected in the wastewater discharges of the Baghdad governorate's textile industries. The purpose of this research is to investigate the electrocoagulation degradation of the textile dye Imperon Violet KB in an aqueous solution with an initial concentration of 100 mg/L. The impact of EC operative factors including density of current, touch time, pH, concentration of initial dye and electrolysis support was explored. When the current density is 1.43 mA/cm2, the duration is 20 min, and the primary pH is 6, the results are peak. Color, turbidity and COD elimination efficiencies were 95 percent, 99.5 percent, and 85 percent, respectively. The final pH varies depending on the original pH with a constant density of current and variable passage time. The color removal efficiency is clearly reduced at high initial concentrations. The effect of using NaCl as an electrolysis help resulted in an improvement in conductivity and voltage. When using a concentration of 1.6 g/L of NaCl, the color removal efficiency is 95.5 percent. The kinetic analysis revealed that the dye degrades according to a second-order rate equation.

Land cover has been varying due to urbanization process in developing countries. As a result, land surface temperature has been changing spatially and temporally. The spatial and temporal variations of land surface temp (LST) over Babylon Governorate, Iraq were highlighted in this investigation. Landsat-8 satellite images from 2013 to 2020 have been processed in QGIS software to estimate land temperature remotely and then to link its variation with normalized difference vegetation index (NDVI). The results demonstrated that the maximum temperature was at barren lands (about 62 °C), the mean temperature was between 45 and 51 °C, and the minimum temperature was about 30 °C. Also, the magnitudes of mean NDVI ranged between 0.15 and 0.17. Varying from low to high temperature magnitudes Water, vegetation, and built-up/bare areas occupied about (0.6–1.6) %, (10.2–22.6) %, and (76.1–89) %, respectively. It was found that the temperature distribution in the study area has been impacted by urban development during the study period. In addition, valid linear models were established in order to predict LST in terms of NDVI directly.

The hydrodynamic numerical modeling is increasingly becoming a widely used tool for simulating the surface waterbodies including rivers, lakes, and reservoirs. A challenging step in any model development is the verification tests, especially at the early stage of development. In this study, a unique approach was developed by implementing the volume balance principle in order to verify the three-dimensional hydrodynamic models for surface waterbody simulation. A developed and verified three-dimensional hydrodynamic and water quality model, called W3, was employed by setting a case study model to be verified using the volume balance technique. The model was qualified by calculating the error in the accumulated water volume within the domain every time step. Results showed that the volume balance reached a constant error over the simulation period, indicating a robust model setup.

Tigris River is a major source to supply water for a big part of Iraq. Lately, Iraq has experienced water shortage problems such as variability in climate and the building of huge dams in the upstream countries (Turkey and Iran). In this work, the total dissolved salts (T.D.S.) were measured at fourteen sites on the Tigris River in two periods of the year 2014. The first period consisted of six rainy-months (April–September) and the second period covered non-rainy-months (October-March). Interpolation technique of inverse-distance-weighting (I.D.W.) in ArcGIS was applied to create the prediction maps of the river for (T.D.S.) concentration in both periods. The findings revealed that the (T.D.S.) levels continued to the last site in Al-Qurnah-city (Basrah) from the first site in Fish-Khabur-city (S-1). In the first period, the (T.D.S.) levels at fourteen selected sites were over the levels in the second period. According to World-Health-Organization (2003), the (T.D.S.) concentration on the Tigris River in both periods in 2014 was graded into five classes, then, the prediction maps of the (T.D.S.) classifications were created.

An integrated linear regression technique was developed and validated to model dissolved oxygen in salt lakes by using R software and based on data from Sawa Lake, Iraq. The technique helps understand and evaluate salty aquatic ecosystems in the presence of water quality data gaps. The technique involved selecting the important water quality parameters that have significant statistical relationship with dissolved oxygen. In order to make the regression development simpler, the validation approach was incorporated with the model. Linearity, homogeneity, normality, outliers, and influential data points were verified. The simulation approach was also capable of displaying the interaction between the selected water quality parameters and the other insignificant parameters. The statistical analysis results indicated that dissolved oxygen in salt lakes is a function of total dissolved solids. The developed model represented dissolved oxygen with R-squared of 90.73% and p-value of 1.08E-06. Furthermore, the model results showed that the influence of salty ions on dissolved oxygen/total dissolved solids model is the same. It was found that temperature has a significant impact on the developed dissolved oxygen model. In addition, the model simulation revealed that salt melting surrounding the lake due to temperature variation during the year cycle increased total dissolved solids in the lake water. Consequently, the lake dissolved oxygen levels were impacted.

Author Posting. © American Geophysical Union, 2019. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research-Oceans 124 (2019): 196-211, doi:10.1029/2018JC014313.

This research includes a monitoring and an evaluation of the air pollution levels generated by the re-suspended and airborne dust due to traffic movement at the main busy crossroads of Hilla City, Nader Crossroad and Al-Thowra Crossroad, Iraq. The re-suspended dust is one of the most important contributors towards overall atmospheric pollution, especially when the roads are unpaved or under maintenance with high traffic load such as Nader Crossroad, which was under maintenance to construct a bridge on it. The concentrations of the total suspended particulate matters were determined at the two locations using portable air sampler during traffic rush hour on sunny moderated weekdays for four months, December 2011, February 2012, April 2012, and May 2012. The results have confirmed the contribution of the unpaved roads in air pollution. The results showed that the average TSP levels at Nader Crossroad was higher than the average TSP levels at Al-Thowra Crossroad during the total period of the study in which the minimum TSP level at Nader Crossroad was 5676.67 μg/m3, which was higher than the maximum TSP level at Al-Thowra Crossroad, 4096.41 μg/m3. In addition, the re-suspended dust concentrations that were measured in this study and ranged from 426.06 to 9348.95 μg/m3 are much higher than the American Environmental Protection Agency acceptable limits of national ambient air quality standards for the particulate matter.

A new 3D hydrodynamic model was developed to simulate water quality transport in surface waterbodies. The governing equations are the continuity equation, free surface equation, momentum equation a...

Estimating heat budget factors are important to understand the many physical processes of large lakes and their reaction to the atmosphere. Some of these components are affected by water temperature, while the other depends on atmospheric conditions. This paper estimates the total heat flux for Lawrence lake via a code developed in MATLAB environment. The code can deal with different time resolutions if the lake water surface temperature data were at different time resolutions from the meteorological data. Results showed that solar energy peaks at 842 Watt/m2 at 540 Julian day, which is very normal for a sunny summer day, while the longwave radiation has 204 Watt/m2 as a min value. The back radiation did not make any reaction for the variation, but it revealed a small gradient. Furthermore, evaporation recorded - 67 Watt/m2 as a minimum value at 659 Julian day and 360 Watt/m2 as a maximum value at 578.43 Julian day close to the maximum water surface temperature event.