Amirreza Talaiekhozani

Perspectives of phytoremediation using water hyacinth for removal of heavy metals, organic and inorganic pollutants in wastewater.

The development of eco-friendly and efficient technologies for treating wastewater is one of the attractive research area. Phytoremediation is considered to be a possible method for the removal of pollutants present in wastewater and recognized as a better green remediation technology. Nowadays the focus is to look for a sustainable approach in developing wastewater treatment capability. Water hyacinth is one of the ancient technology that has been still used in the modern era. Although, many papers in relation to wastewater treatment using water hyacinth have been published, recently removal of organic, inorganic and heavy metal have not been reviewed extensively. The main objective of this paper is to review the possibility of using water hyacinth for the removal of pollutants present in different types of wastewater. Water hyacinth is although reported to be as one of the most problematic plants worldwide due to its uncontrollable growth in water bodies but its quest for nutrient absorption has provided way for its usage in phytoremediation, along with the combination of herbicidal control, integratated biological control and watershed management controlling nutrient supply to control its growth. Moreover as a part of solving wastewater treatment problems in urban or industrial areas using this plant, a large number of useful byproducts can be developed like animal and fish feed, power plant energy (briquette), ethanol, biogas, composting and fiber board making. In focus to the future aspects of phytoremediation, the utilization of invasive plants in pollution abatement phytotechnologies can certainly assist for their sustainable management in treating waste water.

An overview of biological processes and their potential for CO2 capture.

The extensive amount of available information on global warming suggests that this issue has become prevalent worldwide. Majority of countries have issued laws and policies in response to this concern by requiring their industrial sectors to reduce greenhouse gas emissions, such as CO2. Thus, introducing new and more effective treatment methods, such as biological techniques, is crucial to control the emission of greenhouse gases. Many studies have demonstrated CO2 fixation using photo-bioreactors and raceway ponds, but a comprehensive review is yet to be published on biological CO2 fixation. A comprehensive review of CO2 fixation through biological process is presented in this paper as biological processes are ideal to control both organic and inorganic pollutants. This process can also cover the classification of methods, functional mechanisms, designs, and their operational parameters, which are crucial for efficient CO2 fixation. This review also suggests the bio-trickling filter process as an appropriate approach in CO2 fixation to assist in creating a pollution-free environment. Finally, this paper introduces optimum designs, growth rate models, and CO2 fixation of microalgae, functions, and operations in biological CO2 fixation.

Application of Proteus mirabilis and Proteus vulgaris mixture to design self-healing concrete

AbstractThis study investigated two indigenous micro-organisms that can be isolated from soil. The isolated micro-organisms could precipitate calcium carbonate. These micro-organisms were applied to design self-healing concretes. Concrete is one of the most important materials which is used to build structures. Strength and durability of concrete is very important. Hence, a lot of research in this field is being conducted. Although a few reports can be found on the use of different micro-organism to design self-healing concretes, no research has been carried out to isolate suitable indigenous micro-organisms in Malaysia. In this study two strains of microorganisms were isolated from soil. Broken concrete was treated by a medium culture (MC) containing micro-organisms. Results of this study showed that, cracked concrete could be filled by calcium carbonate after treating by a MC containing micro-organisms. However, this treatment is not very effective on the strength of concrete. Results of this study can ...

Biofiltration process as an ideal approach to remove pollutants from polluted air

AbstractMost developing and developed countries are facing the problems and challenges of air pollution. Many governments have enacted laws and policies to enforce industrial activities to reduce air contaminating emissions and are mainly carried out by installation of air pollution control systems. Therefore, the use of suitable technique such as biofiltration processes to control air pollutants is necessary. Although many studies have been published on the designing and operations of polluted air treatment using biofiltration processes but a comprehensive review on it is still lacking. Till now due to conceptual designing and operational knowledge, several cases of failure or sub-optimum designing has been reported about the use of biofiltration process to treat polluted air. This paper presents a comprehensive review of biofiltration processes and technology for the control of organic and inorganic pollutants as an ideal approach to remove pollutants from polluted air. It also covers classification, fu...

Evaluation of gas retention time effects on the bio-trickling filter reactor performance for treating air contaminated with formaldehyde

The effect of different gas retention times (GRTs) on the efficiency of formaldehyde (FA) removal has been studied using a bio-trickling filter reactor (BTFR) for obtaining the optimal operating conditions. Mathematical models to determine the optimum process conditions of the BTFR system for FA removal from contaminated air are developed. Approximately 66% of the FA introduced into the BTFR treatment process dissolved in the nutrient solution, and about 34% of the residual FA was still present in the air. The predominant bacteria on the surface of supporting materials are identified as the five bacterial colonies Salmonella bongori, Salmonella choleraesuis subsp. arizonae, Salmonella typhimurium, Serratia entomophila and Serratia ficaria, and they have the ability to metabolise FA from two-phases (gas and liquid), as a source of carbon and energy. The optimum removal efficiencies of 450 mg FA L−1 of contaminated air ranged from 95 to 99% are verified for GRTs ranging from 100 to 150 s. Exponential models are proposed as a new approach for determining the optimal operating conditions of the BTFR system and can make significant contributions to improving the air quality.

Removal of formaldehyde from polluted air in a biotrickling filter reactor

AbstractOptimization of biotrickling filter reactor (BTFR) for the removal of formaldehyde contained in synthetic contaminated air was investigated. The importance of formaldehyde from contaminated air is necessary mainly because it is toxic, carcinogen, and mutagen for humans. Although several studies have been conducted on formaldehyde removal by using BTFR from contaminated air, but optimum conditions for formaldehyde removal is not being studied using a trustable method. The determination of optimum condition to remove formaldehyde was carried out with Taguchi experimental design method. The influence of different factors (pH, nitrogen, phosphorus, formaldehyde concentration) on formaldehyde removal efficiency in BTFR was determined, and the optimum condition for maximizing this response was obtained. The result shows that pH has a greater effect on BTFR efficiency for formaldehyde removal. By operating BTFR in optimum condition, the removal rate increased up to 98%. Thus, the operation of BTFR at opt...

Microplastics pollution in different aquatic environments and biota: A review of recent studies

Microplastics (MPs) are generated from plastic and have negative impact to our environment due to high level of fragmentation. They can be originated from various sources in different forms such as fragment, fiber, foam and so on. For detection of MPs, many techniques have been developed with different functions such as microscopic observation, density separation, Raman and FTIR analysis. Besides, due to ingestion of MPs by wide range of marine species, research on the effect of this pollution on biota as well as human is vital. Therefore, we comprehensively reviewed the occurrence and distribution of MPs pollution in both marine and freshwater environments, including rivers, lakes and wastewater treatment plants (WWTPs). For future studies, we propose the development of new techniques for sampling MPs in aquatic environments and biota and recommend more research regarding MPs release by WWTPs.

Evaluation and analysis of gaseous emission in landfill area and estimation of its pollutants dispersion, (case of Rodan in Hormozgan, Iran)

Background: The biogases are the mixture of gases produced through the microbial decomposition of organic waste which are amply observed in the landfills. The main purpose of this study was to estimate the emission rates of landfill gases such as carbon dioxide, methane and non-methane organic compounds (NMOCs) in the solid waste landfill of Rodan city in Hormozgan province. Methods: All the necessary information such as population, geographic and climate of Rodan city were collected. Solid waste analysis was then conducted. Afterward, the LandGEM software is used in this study for the purpose of estimation of total biogas, methane, carbon dioxide and NMOCs emission from Rodan’s landfill. Results: The analysis of results showed that only 24.18% of the produced waste in this city is perishable. The calculations indicate that the peak of biogas production which is equal to 420 tons per year would be achieved in the year 2019. The production rates of carbon dioxide and methane in the same year would be equal to 308 and 112 tons per year respectively. The pollutants transmittance calculations in the vicinity of the landfill revealed that the maximum pollutant concentration is within the maximum distance of 200 m. Conclusion: The results obtained in this study could be used for the purpose of design and installation of extraction or incineration equipment in the landfill of Rodan. Keywords: Solid waste, Landfill, Biogas, Rodan city, LandGEM

Hydrogen sulfide and organic compounds removal in municipal wastewater using ferrate (VI) and ultraviolet radiation

Background: In this study, ferrate (VI) and ultraviolet (UV) radiation were employed to remove hydrogen sulfide from municipal wastewater resulting in a reduction in chemical oxygen demand (COD). Although ferrate (VI) and UV have been used individually for the removal of a few pollutants from urban and industrial wastewater, there exists no study to investigate the effectiveness of simultaneous utilization of both methods for the removal of hydrogen sulfide and reducing COD. Methods: This study aims to compare the application of UV, ferrate (VI) and UV/ferrate (VI) for the removal of hydrogen sulfide and COD from municipal wastewater in batch mode. Moreover, the effect of many parameters such as ferrate (VI) concentration, temperature, hydraulic retention time (HRT) and pH on ferrate (VI) oxidation power, were investigated. Results: The results of this study demonstrated that for pH less than 2, higher pollutant removal efficiency was obtained. COD removal efficiency could increase up to 68% by adding 1.68 mg/L of ferrate (VI), almost 100% of hydrogen sulfide was removed by the same concentration of ferrate (VI). Both hydrogen sulfide and COD removal efficiencies increased as temperature increased to 50°C; nevertheless, further increase in temperature had negative effect on the removal efficiency. The use of UV/ferrate (VI) increased the removal efficiency of both hydrogen sulfide and COD when compared with the use of UV and ferrate (VI) individually. UV method was not effective in the removal of hydrogen sulfide. Conclusion: The research findings shed new light on wastewater treatment systems employing UV/ ferrate (VI) to decrease both the hydrogen sulfide and COD of municipal wastewater. This new findings will assist in the inaccurate design and effective operation of such systems which can be employed to maintain or improve environmental quality.

Investigation of formaldehyde removal from synthetic contaminated air by using human hair

Background: Human hair can be used as an inexpensive and accessible adsorbent to remove a variety of pollutants from air. Although several studies have been done on removal of formaldehyde from wastewater by human hair, to date no study has investigated using hair to remove formaldehyde from air. Therefore, the aim of this study was to remove formaldehyde from synthetic contaminated air by a reactor packed with human hair. Methods: Air contaminated with formaldehyde was introduced into a cylindrical reactor packed with human hair at the initial concentration of 8500 mg/L. Formaldehyde concentration was measured in the influent and effluent of the reactor to indicate formaldehyde removal efficiency. Other measurements of parameters effective on formaldehyde removal were taken including amount of human hair and environmental temperature. Results: Results of this study revealed that each gram of human hair was able to remove 0.13 to 0.49 g of formaldehyde from air. Human hair adsorbed 98% of formaldehyde from synthetic contaminated air under 20 ̊C. These results demonstrate that increased temperature had a negative effect on formaldehyde removal. Conclusion: Results of this study show that human hair can be applied as a simple and inexpensive adsorbent to remove formaldehyde from industrial air exhaust. In addition, results of these tests can be considered as a small step to promote better air quality. Keyword: Formaldehyde, Human hair, Adsorption process, Air treatment Citation: Talaiekhozani A, Talaei MR, Yazdan M, Mir SM. Investigation of formaldehyde removal from synthetic contaminated air by using human hair. Environmental Health Engineering and Management Journal 2016; 3(4): 191–196. doi: 10.15171/EHEM.2016.19. *Correspondence to: Amirreza Talaiekhozani Email: atalaie@jami.ac.ir Article History: Received: 8 July 2016 Accepted: 15 September 2016 ePublished: 28 September 2016 Environmental Health Engineering and Management Journal 2016, 3(4), 191–196 Introduction Nowadays, industry produces many different pollutants in the form of gases, liquids and solids, which are released into the environment (1-3). Therefore, it is essential to control emissions of wastewater, exhausted gases and solid waste by developing treatments methods for application before they are released (2,4,5). Exhausted gases emitted from industry contribute to air pollution (6). Several air pollutants are harmful to humans by causing cancer or infertility (7). Air treatment is more complex than wastewater or solid waste treatment and needs more developed technology (8,9). Formaldehyde is widely used in industry and released into the atmosphere where it is a pollutant (10). Formaldehyde is a highly toxic, teratogenic, carcinogenic and mutagenic substance and thousands of tons are released into the atmosphere yearly (11). Formaldehyde can be absorbed from the air into seas and oceans where it generates water pollution. Formaldehyde is a basic chemical used in the production of keratin-based hair smoothing products. Formaldehyde is a listed dangerous chemical (1-3). This causes some manufacturers, importers, or distributors use other terms for chemical formaldehyde on their product information. There are many alternative terms used for formaldehyde including methylene glycol, formalin, methylene oxide, paraform, formic aldehyde, methanal, oxomethane, oxymethylene, timonacic acid or CAS No. 50-00-0 (12). These alternative terms mean that some products are labeled and marketed as formaldehyde free. Workers in beauty salons breathe in the formaldehyde released from such hair smoothing products or they may absorb it through their skin. Workers in beauty salons are exposed to formaldehyde during all hair straightening processes, particularly if the temperature is increased by use of tools such as during blow-drying or flat ironing processes (1). Occupational Safety and Health Administration (OSHA) recommends the maximum concentration of formaldehyde in air at 0.15 and 8 hours exposure is 2 Environmental Health