Zarook Shareefdeen

Biotechnology for odor and air pollution control

Biotechnology for odor and air pollution control , Biotechnology for odor and air pollution control , کتابخانه دیجیتال جندی شاپور اهواز

Review of current technologies used in municipal solid waste-to-energy facilities in Canada

The increasing amounts of municipal solid waste produced accompanied with the rising need for energy has caused a growth in the popularity of waste-to-energy (WTE) facilities as waste and energy solutions for many regions in Canada. The recent commercially viable WTE facilities across Canada show that the main technologies used in Canada are incineration, gasification, and plasma gasification. The aim of this study is to present these WTE technologies through the examination of case studies taken from the existing facilities across Canada. Background information on case studies, information on the WTE process, and a comparison highlighting the differences between the facilities are discussed.

Management and control of air emissions from electronic industries

Volatile organic compounds (VOCs) including acetone, dichloromethane, ethanol, ethylene glycol, iso-propyl alcohol, and several other aromatic compounds are emitted during the manufacturing processes in electronic industries. These VOCs pose problems to human health and the environment. Stringent environmental legislations imposed by government agencies on VOCs force electronic industries to adopt effective air pollution-treatment methods. This article provides a detailed review of VOCs that are emitted from different processes in the electronic industry, conventional, and current technologies that are used to remove toxic air pollutants and an innovative application of biotechnology for removal of VOCs from electronic industry.

Dynamic modeling and analysis of biotrickling filters in continuous operation for H2S removal

A number of important biotrickling filter (BTF) models are reviewed. For our study, a theoretical model, based on H2S removal in a differential BTF under batch mode, was selected among the models reviewed. Using a cascade of BTF units in series, in this work, we have extended the model for continuous operation under dynamic conditions and the model accuracy is verified under a limiting case. The modified model was successfully simulated and used in the performance evaluation of a continuous BTF. Sensitivity analysis of the BTF performance in a continuous operation revealed that liquid–gas velocity ratio (LGVR) has negligible effects as compared to the effects of inlet concentration of H2S and gas velocity. The modified model extends the applicability of the model for full-scale design, process identification and control systems of a BTF in a continuous operation.

Hydrogen sulfide (H2S) removal using schist packings in industrial biofilter applications

Expanded schist can be a promising biofilter media for Hydrogen Sulfide (H2S) removal in industrial applications. In this work, H2S removal performance of a biofilter packed with expanded schist is compared with a patented (EU Patent No. 0 497 214 B1) media which has been commercialized and used in many industrial applications for odor and VOC control from contaminated airstreams. Hydrogen sulfide (H2S) removal performance data from two different schist packing media combinations were used in the analysis (BF1: inoculated with activated sludge, BF3: inoculated with activated sludge and 12% synthetic nutrient-UP20). Different mathematical models that describe H2S removal performance of a patented and schist packing media, respectively, were used to determine the limitations, similarities and differences of both media. The results show that both model predictions are in close agreement with the experimental data of schist packing that is inoculated with activated sludge (BF1). Thus, patented media removal performance of H2S is closely equivalent to expanded schist media inoculated with activated sludge (BF1). When model comparisons are made on a similar basis with schist media inoculated with activated sludge and 12% UP20 nutrient (BF3), the removal performance of schist media is found to be superior to that of patented biofilter media, especially for loading rate greater than 7 g/m3 media/hr. Since the patented biofilter media (EU Patent No. 0 497 214 B1) is commercially used by many industries, the results presented in this work will be valuable for practicing engineers and consultants who work in full-scale design and operation of biofilters.

Winter Operation of Biofilters for Hydrogen Sulphide Removal

Hydrogen sulphide (H2S) is one of the main odor causing, toxic, and corrosive chemicals found in wastewater treatment, pulp and paper and several other industries. One of the main challenges of winter operation of biofilters for H2S removal is to deal with the heat effects of biofiltration process. During winter lower air temperature, snow fall on biofilter vessels and moisture condensation in air ducts decrease percent removal of H2S significantly. In this work, laboratory and field data that are collected during winter operation of biofilters are analyzed and presented. The results demonstrate that temperature within the biofilter should be maintained at a minimum of 15°C to avoid lower percent removal or odor breakthrough resulting from untreated H2S emissions in the air. It was found that heat input to the incoming air by steam addition easily remedy the problem.

Methods for Monitoring and Assessment of Bioremediation Processes

The cleanup of the contaminated soils is a priority environmental task due to the risks contaminants pose to the groundwater, drinking water and soil fertility. A wide variety of biological, physical and chemical methods have been developed to decontaminate polluted sites. Any successful remediation technology should not simply transfer the contaminants to other environmental compartments. Bioremediation provides a cost-effective and contaminant/substrate-specific treatment technology (Ward et al. 2003). A successful bioremediation approach requires sufficient proof for the detoxification of the contaminants, preferably proven by complete mineralization (Dua et al. 2002). However, the determination of effectiveness and completeness to satisfactory status is one of the major problems. Current monitoring practices require the determination of the disappearance of the contaminants and their degradation products to regulatory levels are monitored followed by toxicity testing, usually on a single organism or species to make sure that there is no product or induced change resulting in any residual toxicity. The problems related to these monitoring approaches and to the assessment of successful bioremediation have been widely recognized and discussed (Hohner et al. 1998; White et al. 1998; van Straalen 2002; Widada et al. 2002a). The microbial community response may prove to be a much more comprehensive indicator of residual toxicity, which is more sensitive than single species toxicity screens, and can be used to complement the disappearance or sequestration of contaminants.

Factorial design analysis for adsorption of sulfur compounds from diesel oil on activated charcoal

Batch adsorption equilibrium of the sulfur compounds from diesel oil using two types of commercial activated carbon was studied in a two-level factorial experimental design method. This technique has been used to investigate the impacts of several factors controlling the adsorption process, such as source of sorbent material, amount of sorbent material used, and temperature. High percentages of adsorption of sulfur compounds were obtained using the sorbent materials tested. The analysis of variance and the factorial design of experiments showed that the amount of sorbent material used was the most significant factor under the experimental ranges studied. Also, a predictive regression model for the experimental data was generated. The capability of the generated regression model was studied, where excellent agreement between the experimental and predicted values was observed.

Design and analysis of a simulated methanol production plant

The demand for cleaner and alternative energy is growing rapidly leading to interest in methanol production. Methanol is a high value chemical that serves as an intermediate for producing common chemicals, use as a fuel additive, and as a method of energy storage. This work is about a design of a methanol plant with a production capacity of 5000 metric tonnes per day (MTPD). The design of the plant is also limited by the quality of methanol produced - Grade AA (99.85% methanol minimum, 0.1% water maximum), and to produce no more than 0.54 tonne CO2 emissions per tonne methanol produced. The heart of the design is to model the low pressure methanol technologies and to identify the advantages of different reactor types. In terms of economics, the growth in the demand for methanol has been seen to have a steady increase over the past few years. Based on the initial estimates for the plant costs, the capital required to build the plant is between 1-1.1 billion USD. Current market prices for a 5000 MTD plant would make a yearly gross income of approximately 50-100 million.

Biofilter Response to Upsets in Process Conditions

Full scale biofilter systems are often subjected to variations in operational and environmental conditions. Occasional fluctuations in the flow rate, temperature, concentrations of process emissions, and pH drops are commonly encountered. In this work, a general transient biofilter model which incorporates axial dispersion effects, interactive kinetics, multi-component adsorption effects and oxygen limitations aspects have been used to study the dynamic behavior of biofilters to process upsets. Biofilter performance under sinusoidal and triangular perturbations of concentrations, flow rate, and media pH are presented. The results of this study will be useful in the designing and process control of biofilter systems that are exposed to varying operational conditions.