Shaheen Aziz

A Promising Technology of Pressure into Power: A Case Study of Pressure into Power Approach in Gas Transmission Lines in Pakistan

Pakistan is gas rich but power poor country. Conventional approach is always directed toward power plants using fossil fuel. Some trials have also taken place demonstrating wind and other nontraditional energy source for generating electricity. A pragmatic and feasible unexploited resource is the potential energy from high-pressure natural gas. Currently, this energy is being wasted at gas pressure reducing stations in Pakistan. At present there are two integrated gas companies (transmission and distribution), i.e., Sui Southern Gas Company Limited (SNGPL) and Sui Northern Gas Pipelines Limited (SSGCL). The gas is transmitted through the transmission pipelines in the pressure ranges of 800–1,000 psig. The gas is distributed by reducing from the transmission pressure into distribution pressure up to a maximum level of 150 psig at the city gate stations normally called “sales metering station (SMS).” There are almost more than 200 SMSs in SNGPL and SSGCL. This study highlights real possibilities to utilize the energy lost in gas reducing stations (SMSs) as a source of electrical power. The present study shows that with average pressure ratio (ratio of upstream to downstream pressure) of 10 and average gas flow of 35 MMSCFD from any gas metering station, more than 2 MWe power could be generated without consumption of any fuel.

Utilization of Sewage Sludge for Production of Electricity using Mediated Salt Bridge Based Dual Chamber Microbial Fuel Cell

For developing a feasible world we need to reduce the utilization of fossil fuels and also the pollutant production. These two aims can be fulfilled by treating the waste like sewage sludge. Sewage sludge is a perfect substrate for power generation as they rich in organic substance. This study consolidated bio-cathode with in a dual chamber MFC to generate voltage from sewage sludge (2 L) at a maximum voltage generated of 2.5 V. The use of bio cathode generates an internal resistance of 36-46 ohm, hence yielding maximum voltage generation (2.5 V) from MFC. Saccharomyces cerevisiae sp. was used as biocatalyst. Methylene blue (10 ml) was used a mediator and potassium ferricyanide (350 ml) was used as an oxidizing agent for the conversion of sewage sludge into voltage generation. In this MFC, anode solution was in batch and cathode was in continuous mode of operation under optimum conditions of the operating parameters like pH, oxygen flow rate and substrate concentration.

Municipal Solid Waste Management: Options for Its Treatment and Energy Recovery

The amount of municipal solid waste (MSW) generation varies with the population, seasonal variation, and also with the localities of the cities. Different treatment methods are available for the treatment of MSW. These methods also depend upon the composition of MSW and the facilities available in that particular locality. The most commonly used treatment methods include land filling, composting, and incineration. In this study, estimates were worked out for the amount of MSW generated in seven large cities (Karachi, Lahore, Faisalabad, Hyderabad, Multan, Peshawar, and Quetta) of Pakistan during the period 1998–2008. Based on the available data, estimations have also been made by extrapolation for the next decade. The population of selected cites is in millions and is increasing rapidly every year. These cities generate huge quantities of MSW daily; however, these wastes are not managed properly. Populations beyond control and poor management of MSW have further been the reasons of environmental pollution and spread of disastrous diseases in these localities. Incineration technology has been focused as it involves the combustion of organic materials and/or substances. Studies further revealed that incineration reduces the volume of MSW to 95%. From the current statistics, the electricity/power potential of Karachi (204.3 MWh), Lahore (140.6 MWh), Faisalabad (37.3 MWh), Hyderabad (22.6 MWh), Multan (23.6 MWh), Peshawar (17 MWh), and Quetta (9.54 MWh) had been worked out. The studies suggest that by adopting incineration technology for MSW management, the volume of MSW can be reduced substantially in addition to power generation, which will lessen the burden on other sources.

Industrial Effluent Treatment by Photocatalytic Degradation of Sodium Dodecylbenzensulfonate (DBS)

Surfactants in the environment are a prerequisite for the sustainable development of human health and ecosystems. Surfactants are important in daily life in households as well as in industrial cleansing processes. It is important to have a detailed knowledge about their lifetime in the environment, their biodegradability in wastewater treatment plants and in natural waters, and their ecotoxicity. Most of the issues on environmental acceptability focus on the effects on the environment associated with the use and disposal of these surfactants. These effects are taken into account by a risk assessment. The first step in a risk assessment is to estimate the concentrations of surfactants in the environmental compartment of interest, such as wastewater treatment plant effluents, surface waters, sediments, and soils. This estimate is generated either by actual measurement or by prediction via modeling. The measured or predicted concentrations are then compared to the concentrations of surfactant known to be toxic to organisms living in these environmental compartments. There are many situations where industry is producing both heavy metals ions and organic pollutants. Successful treatment of effluents of this type to achieve legislative compliance will depend on whether the heavy metals effect the process of degradation of the organic species and whether the presence of organic molecules hinder the process of removal of heavy metals. Degradation of cationic surfactant was studied with a photolytic cell system. Compressed air was used as oxidant and the temperature was maintained at 25–30°C. Effects of UV source, hydrogen peroxide (H2O2), and titanium dioxide (TiO2) on sodium dodecylbenzensulfonate (DBS) were recorded. High-performance liquid chromatography (HPLC) and infrared spectroscopy (IR) were used to analyze the rate of degradation of C24H39NaO5.

Utilizing Dairy Wastewater for Electricity Generation Using Environment-Friendly Double Chambered Microbial Fuel Cell

Microbial Fuel Cells (MFCs) provide a novel bioprocessing strategy to produce sustainable energy and wastewater treatment. It produces electricity and under certain conditions, biogas from biodegradable compounds and simultaneously reduces carbohydrates and complex substrates in wastewater. MFC with saline catholyte was used in this laboratory scale study. Salt-bridge of dimensions of 5 cm length and 2 cm diameter was used in a plastic MFC unit with electrodes manufactured to the same dimensions (5×5). Dairy waste water was used as the substrate, with its microorganism as the biocatalyst. The dual chambered MFC was operated at room temperature. The study was carried out in three experiments. In the first experiment, the maximum voltage of 0.36 V and current of 0.35A was generated. In experiment 2 and 3 the maximum voltages were 0.42 V, 0.46 V and maximum current were 0.36A and 0.42A respectively were obtained per liter of the dairy wastewater. The MFC was operated for 7 days while the performance was monitored every 1 hr. The main aspects of MFC research are to produce the cost of treatment as well as simplifying operational or functional conditions. MFCs can be the next generation of fuel cell technology and thus might play an important role in energy conservation, electricity generation, bio-hydrogen production, biosensors and wastewater treatment as well as in alternate fuel utilization using microbes to generate electricity.

Hospital Waste Generation and Management: A Case Study of Hospitals in Karachi, Pakistan

The management and treatment of hospital solid waste are one of the major concerns all over the world, in specific in developing countries, because of its infectious nature in general. In developed countries, this type of waste is properly treated using technology and the disposed, but in developing countries, the problems still exist because of multidimensional limitations. One of the major limitations is the availability of baseline date for waste generation, classification, and analysis. The hospitals are generally not concerned about all these data. The major reason is the lack of monitoring of stack holders, i.e., local government, EPA, etc., in addition to lack of awareness in the community. The current study focuses on the collection of waste from major hospitals in Karachi. The research team collected data from the various wards of the selected hospitals. It was found that the medical and gynecology wards are the largest waste producers because of the number of bed. The civil hospital was the largest waste producer. The amount of kilograms per bed is in the range of 2.228–6.800.

Environmental Impact of Untreated Effluents from Sugar Industry: A Case Study

Sugar industry, being the major consumer of water, discharges its effluents into the outside environment mostly as untreated. However, besides knowing about the pollution strength of these effluents, knowledge about the mode of disposal of these effluents into the surroundings is also crucial. Thus, an intensive investigation was carried out to know the disposal patterns adopted by three selected sugar mills, namely, Habib Sugar Mills, Nawabshah, Matiari Sugar Mills, Matiari, and Fauji Sugar Mills, Tando Mohammad Khan, along with the obvious problems people were facing as a result. The study concluded that the disposal of untreated effluents into the surroundings had a negative impact on the resources such as land and water (both surface and ground) in particular and on the health of people and their livestock in general.

Value-Added Product Recovery from Banana Plant Waste: A Sustainable Way for Development

Pakistan being an agriculture country is enriched with abundance of biomass residues from agricultural crops such as wheat straw, rice husk, bagasse, banana plant, etc. that may be used for resources recovery. The banana plant is one of the potential cellulosic material like cotton crop, wood, etc., obtained from agricultural land. Development in the area of bio-conversion offers a cheap and safe method of not only disposal of agricultural residues but may also be used for the production of product, like, ethanol. Ethanol production from cellulosic material is a two stage process. Initially, the cellulosic material is converted to reducing sugar by acid hydrolysis or enzymatic hydrolysis and afterward, production of ethanol by fermentation process. The current work focuses on the optimization of acid hydrolysis and fermentation using Sacchromyces cerevisiae yeast. In the current study, process conditions for acid hydrolysis, i.e., particle size, reaction time, shaking speed, temperature and concentration of acid were studied in addition to fermentation process optimization. In acid hydrolysis, samples of various particle sizes, i.e., 26, 28, 30, 40, 50, and 100 μm, were used. It was found that reduction in particle size enhances the conversion of reducing sugars from banana plant. The optimized conditions for hydrolysis were found to be shaking time 2 h, temperature 80°C, shaking intensity 90 rpm, and solid–liquid ratio 50 g in 300 ml of H2SO4. With 100-μm particle size, optimum yield of Brix (reducing sugar) was obtained (21–24% per 300 ml). pH was adjusted in the range of 4.5–5.2. For the production of ethanol, aerobic fermentation was carried out using S. cerevisiae yeast species. The fermentation reaction was carried out in a 300-ml conical flask. Optimum yield was obtained at 31°C, residence time 8 h, and when shaken at 80 rpm.

Ethanol Production from Molasses Using an Indigenous Strain of Thermotolerant Kluyveromyces marxianus Under Controlled Conditions

Ethanol produced by a fermenting renewable crop such as sugarcane molasses is a very cheap source of alternative fuel. All the developed and some developing countries have taken up bioethanol as an alternative energy source. This situation arises because of the depletion of the fossil fuel reserves, rising costs, and environmental impacts. This study shows that a newly indigenous strain isolated as a mutant strain of thermotolerant Kluyveromyces marxianus M15 produced a maximum production of ethanol in 48 h. The kinetic parameters have been studied for cell growth, substrate consumption, and ethanol production for wild and mutant strains of K. marxianus M15. It has been observed that the wild strain was growing up to 55°C, while the mutant strain was growing up to 65°C. In this study, the mutant strain M15 was proved to be stronger than its parental culture due to its microbial activity. K. marxianus were grown in a 23-l fermentor (working volume 15 l) on different substrates, including glucose, sucrose, and molasses at concentrations of 10, 12, 15, and 17%. Total sugars were tested for their ability. M15 produced maximum ethanol of 72.5–75.2 g l−1 with concentration of 15%, and β-fructofuranosidase (F-Fase) at 72 and 48 h, respectively.