Search Results (10)

In this study, a decentralized new sewage water treatment system is suggested and designed in Ar Riyadh, Saudi Arabia, to safeguard the environment and reuse treated water for irrigation purposes. The system consists of a primary treatment (septic tank), a subsurface horizontal flow constructed wetland (HSSF-CW), and a storage ground tank. The research methodology employed in this study is (i) to define the wastewater characteristics, where air temperature in winter is 18.6 °C, the wastewater flow per person (q) is 150 L/d, demonstrating an inlet design discharge of 300 m³/d, the influent pollutant concentrations for biological oxygen demand (BOD), total suspended solids (TSS), chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP), and fecal coliforms (FC) are 350, 1000, 700, 50, 12 mg/L, and 10⁶ CFU/100 mL, respectively; (ii) to design the septic tank based on a retention time of two days and a surfacing load rate of 1.5 m/d; (iii) the P-k-C* model was used to determine the HSSF-CW surface area based on reed beds of Phragmites australis (common reed) and papyrus plants, where the removal rate was constant at 20 °C for BOD, TP, and FC in the effluent concentrations not exceeding 20 mg/L, 3.0 mg/L, and 2000 CFU/100 mL in order to satisfy Saudi Arabia’s wastewater reuse requirements; and (iv) to design the clean water tank for a hydraulic retention time of 10 h. The results demonstrate that the removing pollutants design area is 1872 m² divided into nine cells, each of width 8 m and length 26 m, with a hydraulic loading rate (LR) of 0.16 m/d and a hydraulic resident time (RT) of 1.1 d. The effluent pollutant concentrations for the BOD, FC, TN, and TP were 245 mg/L, 10³ CFU/100 mL, 35, and 8.5 mg/L, respectively. The wastewater treatment system total removal efficiencies for BOD, TN, TP, and FC were estimated to be 91.8, 70, 57, and 98.5%, respectively. Design curves were developed to ease the design steps. The HSSF-CW is a green wastewater treatment technology that offers greatly decreased investment costs, and service particularly for small-scale applications up to 6000 persons. Full article

The aim of this study was to investigate the effect of traffic congestion in urbanized areas (parking lots and highways) on stormwater quality. Three separate locations in Egypt’s heavily urbanized and populous Giza Governorate were picked for the purpose of monitoring and evaluating the stormwater quality: Faisal (A), El Dokki (B), and Hadayek El-Ahram (C), with catchment areas of 10,476, 7566, and 9870 m², and with monthly average daily traffic (MADT) values of 47,950, 20,919, and 27,064 cars, respectively. The physio-chemical and heavy metal stormwater quality parameters of six water samples were investigated and compared with Egypt’s water criteria and the World Health Organization (WHO) guidelines. The water quality index (WQI) and the irrigation water quality indices were used to assess the uses of stormwater. The results showed that the WQI varied from 426 to 929, with an average of (661 $\pm$ 168), indicating that the stormwater was contaminated at each location under examination and needed pretreatment in order to be useful. As a result, the allowed stormwater quality standards were exceeded for heavy metals such as Al, Cr, Cd, Fe, and Cu. The indicators of the stormwater quality for irrigation—the total dissolved solids (TDS), sodium adsorption ratio (SAR), soluble sodium percentage (SSP), permeability index (PI), magnesium adsorption ratio (MAR), and Kelley’s ratio (KR)—show excellent stormwater for irrigation, while the total hardness (TH) and residual sodium bicarbonate (RSBC) indicate poor irrigation water quality. It is advised to sweep the streets to remove particle-bound pollution before it reaches storm drain water, and to put in place an adequate stormwater sewerage system to catch rainwater. Full article

Waterlogging and soil salinity issues can be handled using surface or subsurface drainage networks, soil bed elevation, and soil and crop management patterns. A properly operating and maintained drainage system is important for both rural and urban inhabitants to protect lives and property from flooding and high groundwater levels, enhance health conditions, and safeguards water purity, soil salinity, and waterlogging. It also supports and increases crop yields and consequently rural incomes. This study assessed the maintenance condition of the main surface drains (Baloza and ELFarama) located in the Tina Plain (50,000 acres) and a portion of the Southeast El-Kantara regions (25,000 acres) in North Sinai, Egypt, based on the values of the Discharge Capacity Ratio (DCR) and Manning’s roughness (n). Ten measurement locations at the drain cross-section were used in the investigation. For the ELFarama Drain, the average values of n and DCR were found to be 0.029 and 86.2%, and for the Baloza Drain, they were 0.032 and 78.6%, respectively. Compared to the design values, the actual Manning’s roughness was higher, indicating that the drainage canals’ capacities had been reduced and that their upkeep was inadequate. In both drains, sedimentation is present and they need to be maintained, according to the hydrographic surveying results for the actual cross-sections compared to the planned cross-sections. A methodology for the channel maintenance method is presented. For removing vegetation and dredging sediment, a long-boom mechanical hydraulic excavator with a bucket is suggested and to be conducted every two years. To the results of this study, the amount of weed infestation in vegetated channels is the main factor that affects Manning’s roughness coefficient value. It is now easier to calculate the proportion of weeds that are submerged in vegetated channels using echo-sound sonar technology. The DCR is an affordable and simple methodology to assess the channel maintenance status for sustainable agriculture. Full article

The water supply in Saudi Arabia is already depleted. Climate change will exacerbate the demand for these resources. This paper examines how climate change affects the water demands of Saudi Arabia’s most important food crops: wheat, clover, vegetables, and dates. To reduce the adverse climate change impacts on these crops’ productivity, as well as their irrigation water requirements (IWR), a number of adaptation techniques were investigated. The study was carried out for the Ar Riyadh region, Saudi Arabia, with a cultivated area of 179,730 ha. In this study, five climate models from the Coupled Model Intercomparison Project Phase 6 (CMIP6) for two Shared Socio-economic Pathways (SSPs), SSP2-4.5 and SSP5-8.5, were used to forecast and investigate the potential impacts of climate change on agricultural water resources in the Al-Riyadh Region of Saudi Arabia. To simulate IWRs under the present and projected climate change scenarios, CROPWAT8.0 was used. The results showed that the maximum increase ratio in 2100 under SSP2-4.5 and SSP5-8.5, respectively, will be 4.46% and 12.11% higher than in the current case (2020). The results showed that the projected maximum temperatures in 2100 will be increased by 4.46% and 12.11%, respectively, under SSP2-4.5 and SSP5-8.5, compared to the current case (2020), supporting past research on the Arabian Peninsula that revealed that both short- and long-term temperature increases are anticipated to be considerable. Under SSP2-4.5 and SSP5-8.5, the projected ET_o was found to be increased by 2.18% and 6.35% in 2100, respectively. Given that evapotranspiration closely mirrors the temperature behavior in the study region from June to August, our data suggest that crop and irrigation demand may increase in the mid to long term. The findings indicate that Riyadh, Saudi Arabia’s capital and commercial hub, will require more water to irrigate agricultural land because of the expanding ETo trend. Under SSP2-4.5 and SSP5-8.5, the projected growth irrigation water requirement (GIWR) will be increased by 3.1% and 6.7% in 2100, respectively. Under SSP5-8.5, crop areas of wheat, clover, dates, maize, citrus, tomato, potato, and other vegetables in Ar Riyadh will decrease by 6.56%, 7.17%, 5.90%, 6.43%, 5.47%, 6.99%, 5.21%, and 5.5%, respectively, in 2100. Conversely, under SSP2-4.5, the crop areas will decrease by 3.10%, 3.67%, 2.35%, 3.83%, 2.32%, 4.18%, 1.72%, and 2.38% in 2100, respectively. This research could aid in clarifying the adverse climate change impacts on GIWR in Ar Riyad, as well as improving water resource management planning. Full article

This study investigates the impact of the COVID-19 pandemic and the Ever Given ship blockage on the air quality in Suez Canal region. Nitrogen dioxide (NO₂), sulfur dioxide (SO₂), carbon monoxide (CO), and aerosol optical depth (AOD) were studied, and data were obtained from satellite instruments. The study compared monthly average data for 2020, 2021, and 2022 with a baseline period of 2017–2019 to investigate the pandemic’s effect. The study also analyzed the corresponding period of the canal blockage to identify its impact on air pollution levels. The pandemic had a significant role in decreasing NO₂ by 2.5 × 10¹⁴ molecule/cm² and SO₂ by 0.05 DU due to reduced car traffic and industrial activities. A reduction in AOD by 20% and CO concentration in the range from 3.5% to 4.7% was reported in early 2020. During the blockage, NO₂ and SO₂ levels decreased by 14.4% and 66.0%, respectively, while CO and AOD index increased by 12.68% and 51.0%, respectively. The study concludes that the containment measures during the pandemic had a positive impact on the environment, which shows how the reduction in the anthropogenic activities, especially industrial and transportation activities, have improved the air quality. Thus, stricter actions are needed to protect the environment; for example, the transition towards the using of electric vehicle is necessary, which is part of Egypt’s strategy to transition towards a green economy. The government should also adopt a policy to trade carbon emissions reduction certificates to help reduce air pollution. Full article

In the coming years, climate change is predicted to impact irrigation water demand considerably, particularly in semi-arid regions. The aim of this research is to investigate the expected adverse impacts of climate change on water irrigation management in Saudi Arabia. We focus on the influence of climate change on irrigation water requirements in the Al Quassim (97,408 ha) region. Different climate models were used for the intermediate emission SSP2-4.5 and the high emission SSP5-8.5 Coupled Model Intercomparison Project Phase 6 (CMIP6) scenarios. The FAO-CROPWAT 8.0 model was used to calculate reference evapotranspiration (ETo) using weather data from 13 stations from 1991 to 2020 and for both the SSP2-4.5 and SSP5-8.5 scenarios for the 2040s, 2060s, 2080s, and 2100s. The findings indicated that, for the 2100s, the SSP2-4.5 and SSP5-8.5 scenarios forecast annual average ETo increases of 0.35 mm/d (6%) and 0.7 mm/d (12.0%), respectively. Net irrigation water requirement (NIWR) and growth of irrigation water requirement (GIWR) for the main crops in the Al Quassim region were assessed for the current, SSP2-4.5, and SSP5-8.5 scenarios. For SSP5-8.5, the GIWR for the 2040s, 2060s, 2080s, and 2100s are expected to increase by 2.7, 6.5, 8.5, and 12.4%, respectively, compared to the current scenario (1584.7 million m³). As a result, there will be higher deficits in 2100 under SSP5-8.5 for major crops, with deficits of 15.1%, 10.7%, 8.3%, 13.9%, and 10.7% in the crop areas of wheat, clover, maize, other vegetables, and dates, respectively. Optimal irrigation planning, crop pattern selection, and modern irrigation technologies, combined with the proposed NIWR values, can support water resources management. The findings can assist managers and policymakers in better identifying adaptation strategies for areas with similar climates. Full article

Point and nonpoint wastewater sources have a detrimental, negative effect on agriculture, soil, surface, and groundwater supplies. In this research, a wastewater treatment system made up of a sedimentation tank, a horizontal subsurface flow constructed wetland (HSSF-CW), a vertical subsurface flow constructed wetland (VF-CW), and a storage tank was proposed, designed, and cost estimated. Small populations in underdeveloped nations with dry and semi-arid climates can use the treatment system as an affordable construction, maintenance, and operational solution for wastewater treatment. The system will protect agricultural lands and groundwater from pollution. The system can service 6000 capita and has a wastewater discharge of 780 m³/d in the developing arid region in El-Moghra Oasis western desert of Egypt, where the 1.5 million acres used for the land reclamation project based on groundwater irrigation. The relaxed tanks in a series model based on the areal loading rates and background pollutants concentrations (P-K-C*) was utilized to size the HSSF and VF-CWs. The results indicated that the HSSF-CW design treatment surface area was 2375 m², and the hydraulic surface loading (q) and hydraulic retention time (RT) were 0.33 m/d and 0.55 d, respectively, and utilizing Phragmites australis and Papyrus for the biological treatment. The expected overall cumulative removal efficiencies were 96.7, 70, and 100% for the biological oxygen demand (BOD), total phosphors (TP), and fecal coliforms (FC), respectively. The VF-CW indicates that there was a 2193 m² design treatment surface area, q = 0.36 m/d, and RT of 0.63 d. The expected BOD, TP, and FC removal efficiencies were 75, 33.3, and 92.7%, respectively. In order to simplify the design stages and the cost estimation, design and investment cost curves were established for a population range from 500 to 9000. The total monthly water loss due to evapotranspiration for the HSSF and VF-CWs indicates a range from 3.7 to 8.5%, respectively. The total investment cost analysis for the proposed system corresponding to 780 m³/d wastewater discharge of indicates a total investment cost of EUR 146,804 and EUR 24.46/per-capita equivalent (P.E). This approach can be used by decision makers in the Mediterranean region and Middle Eastern countries to improve the water quality using social and economic criteria, leading to the effective implementation of ecological restoration projects as a low-cost treatment system and adding a nonconventional water source that can be used in irrigation. Full article

Practicing agricultural drainage strategies is necessary to manage excess water in poorly drained irrigated agricultural lands to protect them from induced waterlogging and salinity problems. This paper provides an overview of subsurface drainage strategies and the modeling of their performance using the DRAINMOD model. Given that the DRAINMOD model considers a fixed value of the surface depression capacity (SDC) for the whole simulation period, which does not suit many agricultural practices, the paper then assesses the model’s performance under time-variable SDC. It was revealed that adopting a fixed value of SDC for the whole simulation period in the DRAINMOD model causes it to produce improper predictions of the water balance in farmlands characterized by time-variable SDC. Such a model drawback will also adversely impact its predictions of the nitrogen and phosphorus fate in farmlands, which represent major inputs when managing both the agricultural process and agricultural water quality. Researchers should pay attention when applying the DRAINMOD model to farmlands characterized by time-variable SDC. Moreover, it is recommended that the DRAINMOD input module be improved by considering changes in SDC during the simulation period to ensure better management of the agricultural process and agricultural water. Full article

This research investigates the effect of heavy rain on highway traffic volume and average speed, and proposes a recharging well harvesting system as an alternative freshwater source in the context of climate change. The Cairo Autostorad highway was taken as a case study. The highway climate data were collected, and traffic was measured using Metrocount equipment during the period from 2008 to 2020. The results show that the studied road is about 12 km long, and about 40 water ponds exist along the route. Each pond has an estimated water volume of 300 m³, and a 30 cm recharging well, with a maximum recharging capacity of 25 m³/h with satisfactory performance, is recommended to be constructed for rainwater harvesting. The recharging wells will clear the ponding volume within 2.5 to 3.5 h after the rainfall has stopped. The design incorporates a 1.2 safety factor against blockage inside the well. In addition, a model was established between the average rainfall depth and the average measured highway speed for the period (2008–2020) during rainy months, indicating an exponential function with a determination factor R² = 0.7076. The present rainfall (2020) and the representative concentration path (RCP) for 4.5 and 8.5 emissions scenarios were used to simulate the rainfall for future years: the 2040s, 2060s, 2080s, and 2100s. The results show that in the winter season for the current scenario (2020), the average rainfall depth was 45 mm, and the highway speed was 78 km/h. For the RCP 4.5 emission scenarios for the 2040s, 2060s, 2080s, and 2100s, the rainfall depths were 67.8, 126.4, 131.2, and 143.9 mm, and the corresponding reductions in the highway speeds were 23, 34, 35.3, and 36.9%, respectively, compared to the baseline scenario (2020). On the other hand, the RCP 8.5 emission scenarios show a reduction in the highway speed of 23, 34.5, 36.9, and 36.9% for the years 2040, 2060, 2080, and 2100, respectively, due to rainfall depths of 68.7, 128.4, 143.9, and 143.9 mm, respectively. This study helps policymakers to make wise decisions regarding sustainable water resource management and highway traffic problems related to rainwater depths in the context of climate change. Full article

The preservation of water resources in modern urbanized society is a major concern. In this study, a floating constructed wetland (FWT) pilot plant was designed and constructed for the treatment of a polluted wastewater drain. A series of experiments were run continuously for a year in pilot-scale FWTs in a semi-arid area located in Egypt’s Delta. Four aquatic plant species (Eichhornia, Ceratophyllum, Pistia stratiotes, and Nymphaea lotus) were used to assess the performance of FWTs for pollutant removals, such as biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), total nitrogen (TN), total phosphorus (TP), electrical conductivity (EC), and total dissolved solids (TDS), from drainage wastewater to reuse the treated effluent in irrigation practices. The FWT systems were fed drainage tainted water on a weekly basis, and the concentrations and removal efficiency were assessed in the experiments. The average reduction in BOD, COD, TSS, TDS, TN, EC, and TP were 76–86%, 61–80%, 87–95%, 36.6–44.1%, 70–97%, 37–44%, and 83–96%, respectively. ANOVA with Post-HOC t-tests show that the Eichhornia, Pistia stratiotes, and Nymphaea lotus have the highest BOD and COD removal performance, whereas Pistia stratiotes and Nymphaea lotus have the highest TN and TP removal performance. In all cases, the Nymphaea lotus performed well in terms of pollutant removal. In addition, a design procedure for a FWT systems is presented. For wastewater treatment, FWT systems have proven to be a low-cost, long-term option. Full article