Study of PAN Fiber and Iron ore Adsorbents for Arsenic Removal

The main idea to conduct this study is the treatment of hazardous arsenite (As+3)  and arsenate (As+5)from water by two efficient adsorbetns i.e. polyacrylonitrile fiber (organic) and iron ore (inorganic). Polyacrylonitrile (PAN) fibers were chemically modified prior to loading iron using a solution of diethylenetriamine and aluminum chloride hexahydrate. The characterization of PAN fibers was performed through FTIR spectroscopy, which shows the binding of functional groups on PAN fibers surfaces. Atomic absorption spectrometer (AAS) was used to analyze arsenic concentration in samples. The impact of pH, dosage, shaking (contact) time and shaking speed was studied and parameters were optimized for further study. The highest adsorption of 98% is exhibited by modified PAN fiber for As+5 while for As+3 removal is 80%. Modified PAN also showed higher adsorption capacity of 42×103μg/g for As+5 which is better than the As+3 adsorption capacity 33×103 μg/g. Overall results demonstrated that MPAN adsorbent is better than the iron ore adsorbent for the treatment of both As+3 and As+5. Comparative studies of PAN Fiber and iron ore adsorbents revealed that PAN fibers had better adsorption properties than iron ore for As+3  and As+5 in terms of percentage removal and capacity

A Comprehensive Literature Review of Thermochemical Conversion of Biomass for Syngas Production and Associated Challenge

The interest in the thermochemical conversion of biomass for producer gas production since last decade has increased because of the growing attention to the application of sustainable energy resources. Application of biomass resources is a valid alternative to fossil fuels as it is a renewable energy source. The valuable gaseous product obtained through thermochemical conversion of organic material is syngas, whereas the solid product obtained is char. This review deals with the state of the art of biomass gasification technologies and the quality of syngas gathered through the application of different gasifiers along with the effect of different operating parameters on the quality of producer gas. Main steps in gasification process including drying, oxidation, pyrolysis and reduction effects on syngas production and quality are presented in this review. An overview of various types of gasifiers used in lignocellulosic biomass gasification processes, fixed bed and fluidized bed and entrained flow gasifiers are discussed. The effects of various process parameters such as particle size, steam and biomass ratio, equivalence ratio, effects of temperature, pressure and gasifying agents are discussed. Depending on the priorities of several researchers, the optimum value of different anticipated productivities in the gasification process comprising better quality syngas production improved lower heating value, higher syngas production, improved cold gas efficiency, carbon conversion efficiency, production of char and tar have been reviewed

Treatment of Municipal Wastewater Through Horizontal Flow Constructed Wetland

Highly contaminated municipal wastewater is being disposed of into land and rivers without any prior treatment has severe side effects on human and marine animals. This research focused on the treatment of Majeed Keerio village municipal wastewater through horizontal flow constructed wetland system. The experimental study was evaluated and monitored timely over a year. The overall treatment efficiency performance of the wetland system was determined by considering organic pollutants removal efficiency. This study emphasized on the design of horizontal flow constructed wetland for the effective treatment of municipal wastewater of village Majeed Keerio, Sakrand, Sindh. The constructed wetland efficiently reduced COD, BOD5, TSS, turbidity, total phosphate, total nitrogen pollutants of wastewater, which was about 92.3%, 93%, 96%, 96.4% and 74%, respectively. This method reduced all thermotolerant coliforms. Constructed wetland system was found most economical and effective for the treatment of domestic wastewater. The effect of different hydraulic loading rates under varying hydraulic retention times within the constructed wetland was examined. The higher hydraulic retention times resulted in improved pollutants removal efficiency

Thermochemical Conversion of Biomass for Syngas Production: Current Status and Future Trends

The thermochemical conversion of different feedstocks is a technology capable of reducing the amount of biowaste materials produced. In addition, the gasification of feedstock using steam as a gasifying agent also produces hydrogen, which is a clean energy fuel. This article aimed to encapsulate the current status of biowaste gasification and to explain, in detail, the advantages and limitations of gasification technologies. In this review paper, different gasifying agents such as steam, air, and oxygen, as well as their effects on the quality of syngas production, are discussed. In addition, the effects of reactor configuration and different operating parameters, such as temperature, pressure, equivalence ratio, and incorporation of a catalyst, as well as their effects on the ratio of H2/CO, LHV, syngas yield, and tar production, were critically evaluated. Although gasification is a sustainable and ecologically sound biomass utilization technology, tar formation is the main problem in the biomass gasification process. Tar can condense in the reactor, and clog and contaminate equipment. It has been shown that an optimized gasifier and a high-activity catalyst can effectively reduce tar formation. However, key biowaste treatment technologies and concepts must first be improved and demonstrated at the market level to increase stakeholder confidence. Gasification can be the driving force of this integration, effectively replacing fossil fuels with produced gas. In addition, support policies are usually needed to make the integration of biomass gasification technology into the industry profitable with fully functional gasification plants. Therefore, to address such issues, this study focused on addressing these issues and an overview of gasification concepts

Thermochemical Conversion of Biomass for Syngas Production: Current Status and Future Trends

The thermochemical conversion of different feedstocks is a technology capable of reducing the amount of biowaste materials produced. In addition, the gasification of feedstock using steam as a gasifying agent also produces hydrogen, which is a clean energy fuel. This article aimed to encapsulate the current status of biowaste gasification and to explain, in detail, the advantages and limitations of gasification technologies. In this review paper, different gasifying agents such as steam, air, and oxygen, as well as their effects on the quality of syngas production, are discussed. In addition, the effects of reactor configuration and different operating parameters, such as temperature, pressure, equivalence ratio, and incorporation of a catalyst, as well as their effects on the ratio of H2/CO, LHV, syngas yield, and tar production, were critically evaluated. Although gasification is a sustainable and ecologically sound biomass utilization technology, tar formation is the main problem in the biomass gasification process. Tar can condense in the reactor, and clog and contaminate equipment. It has been shown that an optimized gasifier and a high-activity catalyst can effectively reduce tar formation. However, key biowaste treatment technologies and concepts must first be improved and demonstrated at the market level to increase stakeholder confidence. Gasification can be the driving force of this integration, effectively replacing fossil fuels with produced gas. In addition, support policies are usually needed to make the integration of biomass gasification technology into the industry profitable with fully functional gasification plants. Therefore, to address such issues, this study focused on addressing these issues and an overview of gasification concepts

Plastic Waste Recycling, Applications, and Future Prospects for a Sustainable Environment

Plastic waste accumulation has been recognized as one of the most critical challenges of modern societies worldwide. Traditional waste management practices include open burning, landfilling, and incineration, resulting in greenhouse gas emissions and economic loss. In contrast, emerging techniques for plastic waste management include microwave-assisted conversion, plasma-assisted conversion, supercritical water conversion, and photo reforming to obtain high-value products. Problems with poorly managed plastic waste are particularly serious in developing countries. This review article examines the emerging strategies and production of various high-value-added products from plastic waste. Additionally, the uses of plastic waste in different sectors, such as construction, fuel production, wastewater treatment, electrode materials, carbonaceous nanomaterials, and other high-value-added products are reviewed. It has been observed that there is a pressing need to utilize plastic waste for a circular economy and recycling for different value-added products. More specifically, there is limited knowledge on emerging plastic waste conversion mechanisms and efficiency. Therefore, this review will help to highlight the negative environmental impacts of plastic waste accumulation and the importance of modern techniques for waste management