Ghufran Haider Faisal

Bio: Ghufran Haider Faisal is an academic researcher from University of Wasit. The author has contributed to research in topics: Chemical oxygen demand & Wastewater. The author has an hindex of 2, co-authored 2 publications receiving 11 citations.

COD removal from synthetic wastewater using pervious concrete

Abstract: the water clarification properties of pervious concrete pavements composed with varied sizes of aggregate as well as different thicknesses of pavement are studied. Removal efficiency of chemical oxygen demand from wastewater by the pervious concrete was inspected. A sets of experiments consisting of concrete compressive strength, chemical oxygen demand concentration in wastewater was done for this aim. The different sizes of gravel involved to the variation in strength improvement of the porous concrete pavement and its decontamination effectiveness. Chemical oxygen demand was considerably lowered through the voids in the pervious concrete by several processes such as filtration, absorption, and biodegradation resulting in an improvement of the COD removal efficiency. The results showed that higher removal of COD could be done when using a small size of gravel (10-20mm), pavement thickness 20cm and stimulation bacterial growth by adding the nutrients to the wastewater.

Stormwater runoff and pollution retention performances of permeable pavements and the effects of structural factors

Abstract: Permeable pavements, as additive structures that have a good capability for runoff and pollutant reduction, are extensively used for sustainable urban drainage techniques. However, the exact mechanisms of runoff retention and pollutant reduction of a permeable pavement system remain unclear and so, it has become an ongoing issue and motivation for hydrologists and design and structural engineers. In this research paper, a suite of four scale-based runoff plots representing permeable pavements were designed with different permeable surface types and gravel layer thickness treatments, and coupled with simulated rainfall experiments to analyze the impacts of structural factors of permeable pavements on runoff retentions and pollution reduction. The present results showed that the average time to runoff for permeable pavements under low-intensity rainfall scenarios was approximately 78.5 min, while this was shortened to only 51.5 min under high-intensity rainfall scenarios. In terms of the average runoff retention of permeable pavements tested under low- and high-intensity rainfall cases, the results recorded approximately 52.5% and 42.5%, respectively, but runoff retention performances were relatively greater for the case of smaller storms within the scale experiments. Importantly, there was no statistical significance for the time to runoff and runoff retention between the permeable bricks and porous concretes for the analyzed rainfall events. The thicker gravel layers significantly delayed runoff generation and increased runoff retention percentages. Runoff pollutant load reduction rates of total suspended solids (TSS), total nitrogen (TN), and total phosphorus (TP) were varied between permeable bricks and porous concretes. Runoff pollutants load reduction rates of TSS, TN, and TP were highly enhanced while the gravel layer thickness increased from 10 to 20 cm. Higher TSS, TN, and TP pollutant load removals were found from the lower intensity rainfalls. These findings could promote understanding of the hydrologic properties of permeable pavements and help design engineers in optimizing their design of permeable pavements for better runoff retention and pollution removal.

Municipal Wastewater pretreatment using porous concrete containing fine-grained mineral adsorbents

Abstract: Municipal and industrial wastewaters are serious threats for surface water and groundwater resources, and this threat can be converted to an opportunity by enhancing their quality, which then can be used for agricultural and landscape purposes. In the present study, the performance of porous concrete (PC) containing mineral adsorbents was investigated to improve the municipal wastewater quality. Firstly, the performance of adding fine grains (2.36–4.75 mm) in different portions (0, 10, and 20 % w/w of coarse aggregates) as well as mineral adsorbents (0.6–1.2 mm), namely zeolite, pumice, perlite, and LECA, in different portions (0, 5, 10 and 15 % w/w of coarse aggregates) on compressive strength, porosity and permeability coefficient of porous concrete was pursued. After evaluating these parameters, three samples from each percentage of fine-grains that had the highest compressive strength were selected for wastewater qualitative tests due to the fact that there was no significant difference between the other two factors. The experimental setup was next to the wastewater treatment plant of Semnan University, Semnan, Iran, which included a 200-L barrel and six canals to perform the quality tests. Six 100 × 100 × 100 mm PC specimens were positioned in each canal, in a zigzag pattern, to slow down the wastewater flow through the specimens. Inlet discharge for each canal was fixed at 0.5 L/min and total test time was 31.2 h. Qualitative parameters such as total suspended solids (TSS), chemical oxygen demand (COD), biochemical oxygen demand (BOD), and turbidity were measured before and after running the experiment. Results revealed that adding fine grains and the adsorbents increased the compressive strength, while they reduced the permeability coefficient and porosity. Also, the specimens containing zeolite and pumice had the highest compressive strength and permeability coefficient, respectively. Furthermore, mineral adsorbents reduced average concentration of TSS, BOD and COD by 40 %, 48 % and 30.5 %, respectively. The only factor that affected average turbidity level (49 NTU) was porosity, and not the mineral adsorbents. Finally, zeolite had the highest physical characteristics as well as high pollutant-reduction potential. However, it is recommended to perform further tests on different porous concrete mixtures and other adsorbents.

Experimental Comparative Study between Conventional and Green Parking Lots: Analysis of Subsurface Thermal Behavior under Warm and Dry Summer Conditions

Abstract: Green infrastructure has a role to play in climate change adaptation strategies in cities. Alternative urban spaces should be designed considering new requirements in terms of urban microclimate and thermal comfort. Pervious pavements such as green parking lots can contribute to this goal through solar evaporative cooling. However, the cooling benefits of such systems remain under debate during dry and warm periods. The aim of this study was to compare experimentally the thermal behavior of different parking lot types (PLTs) with vegetated urban soil. Four parking lots were instrumented, with temperature probes buried at different depths. Underground temperatures were measured during summer 2019, and the hottest days of the period were analyzed. Results show that the less mineral used in the surface coating, the less it warms up. The temperature difference at the upper layer can reach 10 ◦ C between mineral and non-mineral PLTs. PLTs can be grouped into three types: (i) high surface temperature during daytime and nighttime, important heat transfer toward the sublayers, and low time shift (asphalt system); (ii) high (resp. low) surface temperature during daytime (resp. nighttime), weak heat transfer toward the sublayers, and important time shift (paved stone system); and (iii) low surface temperature during daytime and nighttime, weak heat transfer toward the sublayers, and important time shift (vegetation and substrate system, wood chips system, vegetated urban soil). The results of this study underline that pervious pavements demonstrate thermal benefits under warm and dry summer conditions compared to conventional parking lot solutions. The results also indicate that the hygrothermal properties of urban materials are crucial for urban heat island mitigation.