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Mohammad Y. Ashfaq

Bio: Mohammad Y. Ashfaq is an academic researcher from Florida State University College of Arts and Sciences. The author has contributed to research in topics: Reverse osmosis & Membrane. The author has an hindex of 9, co-authored 19 publications receiving 334 citations.

Papers
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TL;DR: In this paper, the authors highlight characteristics of produced water in detail and physical, chemical, and biological techniques used for its treatment, and reuse of produced waters for different purposes has been discussed.
Abstract: In oil and gas industry, produced water is considered as the largest waste stream, which contains relatively higher concentration of hydrocarbons, heavy metals and other pollutants. Due to the increase in industrial activities, the generation of produced water has increased all over the world and its treatment for reuse is now important from environmental perspective. Treatment of produced water can be done through various methods including physical (membrane filtration, adsorption etc.), chemical (precipitation, oxidation), and biological (activated sludge, biological aerated filters and others) methods. This paper aims to highlight characteristics of produced water in detail and physical, chemical, and biological techniques used for its treatment. In addition, reuse of produced water for different purposes has been discussed. At the end, few case studies from different countries, related to the treatment and reuse of their produced waters have been included.

327 citations

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TL;DR: In this article, the authors investigated the occurrence and diversity of ureolytic bacteria in Qatari soils, specifically to study their acquired potential to adapt to harsh conditions exhibiting urea activity.
Abstract: Biomineralization plays a key role in modifying the geological properties of soil, thereby stabilizing it against wind erosion, especially in areas characterized by harsh weather and harsh soil (calcareous and arid); ie Arabic Gulf region Among soil microorganisms, ureolytic bacteria are capable of modifying soil characteristics and thus, inducing biomineralization This research investigated the occurrence and diversity of ureolytic bacteria in Qatari soils, specifically to study their acquired potential to adapt to harsh conditions exhibiting ureolytic activity Soil samples were collected from various locations in Qatar and were used to isolate the indigenous ureolytic bacteria It was noticed that most of the ureolytic bacteria in Qatari soil belong to the genus Bacillus mainly Bacillus cereus Identification and differentiation of 18 ureolytic isolates were performed using MALDI-TOF MS techniques while ribotyping (16S rRNA) molecular technique was used mainly for 6 selected strains This study not only shows the diversity of species of ureolytic bacteria in Qatari soil but also shows the diversity in their protein profiles, which confirms that bacteria have adapted well to the harsh environment In addition, the strains were evaluated based on a newly modified screening method in this work; ie production of arbitrary urease activity (AUA) Thus, the strains showing the highest AUA, exhibited the highest capability to produce urease enzymes induced by urea Analysis of calcium carbonate precipitation utilizing SEM-EDX showed that the ureolytic bacteria also play a significant role in the precipitation of minerals such as CaCO3, in the presence of urea in soil Therefore, this research showed a high occurrence of indigenous Bacillus bacteria in Qatari soil that can perform biomineralization and thus can be helpful, if properly stimulated, in enhancing soil stabilization, and for other local applications as well, since they are adapted to these soil and weather conditions

46 citations

Journal ArticleDOI
TL;DR: It was found that the increase in temperature enhanced the membrane scaling which was evident by the severe flux decline over time leading to increase in mass of crystals precipitated (Mt) and thickness of the scale layer and there was strong positive correlation between Mt and the temperature.

42 citations

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TL;DR: The polymer-modified GO coated RO membranes were able to diminish both gypsum scaling and biofilm formation demonstrating their potential to control different types of membrane fouling.

39 citations

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TL;DR: By combining the techniques of principle component analysis (PCA) and FTIR, it was demonstrated that the biofouling was more intense and composed of proteins, polysaccharides and lipids, when polymer antiscalant was used.
Abstract: A combination of Fourier-transform infrared (FTIR) spectroscopy, multivariate analysis and conventional microbiological assays were utilized to characterize and differentiate membrane biofouling fo...

29 citations


Cited by
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Journal ArticleDOI
12 Feb 2020-Water
TL;DR: In this paper, a review article describes various applications of nanomaterials in removing different types of impurities from polluted water, which carried huge potential to treat polluted water (containing metal toxin substance, different organic and inorganic impurities) very effectively due to their unique properties like greater surface area, able to work at low concentration, etc.
Abstract: Water is an essential part of life and its availability is important for all living creatures. On the other side, the world is suffering from a major problem of drinking water. There are several gases, microorganisms and other toxins (chemicals and heavy metals) added into water during rain, flowing water, etc. which is responsible for water pollution. This review article describes various applications of nanomaterial in removing different types of impurities from polluted water. There are various kinds of nanomaterials, which carried huge potential to treat polluted water (containing metal toxin substance, different organic and inorganic impurities) very effectively due to their unique properties like greater surface area, able to work at low concentration, etc. The nanostructured catalytic membranes, nanosorbents and nanophotocatalyst based approaches to remove pollutants from wastewater are eco-friendly and efficient, but they require more energy, more investment in order to purify the wastewater. There are many challenges and issues of wastewater treatment. Some precautions are also required to keep away from ecological and health issues. New modern equipment for wastewater treatment should be flexible, low cost and efficient for the commercialization purpose.

365 citations

Journal ArticleDOI
TL;DR: Effective measures to maintain sustainable development in the watershed are proposed, along with a framework for an early warning system adopting the latest technologies (geographic information systems (GIS), remote sensing (RS)) for preventing eutrophication.

148 citations

Journal ArticleDOI
TL;DR: From the literature analysis, it was found that the removal of microplastic by membrane technology is still insufficient, and without the use of specially designed approaches, with the exception of membrane bioreactors (MBRs).
Abstract: Plastic pollution of the aquatic environment is a major concern considering the disastrous impact on the environment and on human beings. The significant and continuous increase in the production of plastics causes an enormous amount of plastic waste on the land entering the aquatic environment. Furthermore, wastewater treatment plants (WWTPs) are reported as the main source of microplastic and nanoplastic in the effluents, since they are not properly designed for this purpose. The application of advanced wastewater treatment technologies is mandatory to avoid effluent contamination by plastics. A concrete solution can be represented by membrane technologies as tertiary treatment of effluents in integrated systems for wastewater treatment, in particular, for the plastic particles with a smaller size (< 100 nm). In this review, a survey of the membrane processes applied in the plastic removal is analyzed and critically discussed. From the literature analysis, it was found that the removal of microplastic by membrane technology is still insufficient, and without the use of specially designed approaches, with the exception of membrane bioreactors (MBRs).

129 citations

Journal ArticleDOI
TL;DR: In this paper, polybenzimidazoleamide (PBI), graphene oxide (GO) and reduced GO (rGO) nanocomposite membranes were developed via the common blade coating and phase inversion technique for the treatment of produced water from the oil and gas industry.

125 citations

Journal ArticleDOI
11 May 2021-Water
TL;DR: A review of the different membrane fouling types, foulinginducing factors, predictive methods, diagnostic techniques, and mitigation strategies, with a special focus on RO membranes, is presented in this article.
Abstract: Membrane-based separation has gained increased popularity over the past few decades, particularly reverse osmosis (RO). A major impediment to the improved performance of membrane separation processes, in general, is membrane fouling. Fouling has detrimental effects on the membrane’s performance and integrity, as the deposition and accumulation of foulants on its surface and/or within its pores leads to a decline in the permeate flux, deterioration of selectivity, and permeability, as well as a significantly reduced lifespan. Several factors influence the fouling-propensity of a membrane, such as surface morphology, roughness, hydrophobicity, and material of fabrication. Generally, fouling can be categorized into particulate, organic, inorganic, and biofouling. Efficient prediction techniques and diagnostics are integral for strategizing control, management, and mitigation interventions to minimize the damage of fouling occurrences in the membranes. To improve the antifouling characteristics of RO membranes, surface enhancements by different chemical and physical means have been extensively sought after. Moreover, research efforts have been directed towards synthesizing membranes using novel materials that would improve their antifouling performance. This paper presents a review of the different membrane fouling types, fouling-inducing factors, predictive methods, diagnostic techniques, and mitigation strategies, with a special focus on RO membrane fouling.

93 citations