Current Environmental Engineering (v.3, #1)

Sanwar A. Sunny
Keywords: This paper explores a real-time resource tracking model and seeks to demonstrate an alternative hot-water production system that uses an air conditioner heat recovery unit and a heat exchanger with a controller system, to develop a business model within a community energy savings program (new construction and existing system retrofits). Buildings account for almost 40% of the U.S. CO2 emissions, where hot water production represents on average roughly 17% to 30% of a household's energy consumption. Simple changes in technologies (innovation and diffusion) and economics (business models) may deter wasteful usage - such as making the system more efficient by using wasted energy or renewable sources of energy, like solar; or allow efficiency and system data to be more available for vendors of energy efficient products to interject and provide services. The current paper encompasses a “Numerically Verifiable Emissions Reduction Device” taxonomy (or NumVERD) where more renewables are integrated, as well as increasing the efficiency of an energy system. The paper hence includes feasibility considerations for an alternative hot water production system that uses the new, low-cost solar collectors using connected devices to track usage and emissions in real time for each household or business - hence it makes an economic case for the de- carbonization of power and enhancing system efficiency from an energy standpoint. The current paper relates the energy and emissions reductions phenomenon by linking the basics of thermodynamics and the economics of greenhouse gas emissions trading using low transaction cost infrastructure and ubiquitous networks, in order to objectively counter the effects of global warming - it thereby introduces a verifiable “figure of merit” for a clean energy technology system for different level of analyses using data and metrics, leading to a regional, or potentially, world-system impact scenario, through instruments such as MARKAL-based modeling. The implications for home use and economic emissions monitoring and trading are therefore succinctly discussed.

Meet Our Regional Editor: by Mohammad Abu Zahra (1-2).

Preface by Jong Moon Park (3-3).

Smoke Clearance in an Underground Car Park using the Jet Fan System by Essam E. Khalil, Sherif M. Gomaa (6-17).
Fires in underground car parks are an important issue. This paper investigates the effect of the jet fan system on the smoke clearance in an underground car park using CFD simulations. Two fire locations were considered with a steady state fire source of 4 MW. The consideration of the fire zone was also studied. The underground car park used in this study is 5290 m2 in area with a height of 3.7 m. A comparison between CFD results and analytical correlations for the fire modeling was made. The ANSYS FLUENT 14.0 software was used for all simulations. The results showed that the temperature is limited to the zone, where the fire is detected, and it is within an accepted range. The CO2 mass fraction was presented and showed how the jet fans contribute in reducing the smoke density and hence improve the visibility. It was found that dividing the car park into zones is highly recommended and should be taken in the design of the jet fan system.

Vertical expansion of Jatropha curcas L by roof-top gardening with pot experimental studies were carried out to produce feedstock of Jatropha for production of biofuel and related byproducts. The plant can grow on eroded land and needs comparatively limited amounts of natural resource and capital inputs and garners much interest from developing nations based on an agrarian societal ecosystem. The experiment also focused in evaluating the physiochemical parameters of resulting Jatropha oil, biodiesel, glycerin and seed cake characteristics after extraction. The seeds of the plants after two years of germination were collected from the earthen pot to extract fuel. After maturity, the plant provided about 250 ml of crude oil per plant and the characteristics of fuel responded better (Flash point of 254°C, Ignition point 323.6°C, Specific gravity of 0.922, Densi- ty 0.919, high Cetane number, or Ignition Quality, of 56.7, Sulfur % of 0.125, Iodine (103.67 mg/g) and Saponifi- cation value of 196.85 mg/g) in comparison to fossil fuel. Higher nutrient content were found in seed cake residue obtained after oil extraction, which could potentially be used as an excellent organic fertilizer, with nutrients value, N = 3.48%, P2O5 = 1.78% and K2O = 1.57%. Also the oil contains a comparatively high percentage of unsaturated fatty acid (79.34%) resulting in characteristically low levels of free fatty acids, which improves storability. The crude oil without any modification could easily be used in lamp for illumination. The high iodine value and the presence of unsaturated fatty acids enables it to remain fluid at lower temperatures. The low sulfur content equates to less harmful sulfur dioxide (SO2) emitted when the fuel is burnt. The crude oil then converted to biodiesel by transesterification process with the byproduct glycerin. 250 ml crude oil could produce about 243 ml of biodiesel. Biodiesel could be used in farming machineries, irrigation pumps, building generator and transporta- tions with greater environmental benefits than conventional carbon-based fossil fuels. Roof-top gardening of plants in this setting also allows for a cooling effect in direct response to urban heat-island effects.

Smoke Behaviour and Management in Large-Domed Mosques by Osama M. Selim, Waleed Abdelmaksoud, Esmail M. ElBialy, Essam E. Khalil (32-37).
Smoke is the most fatal factor that affects the occupants and goods when fire takes place. As it reduces visibility and can cause fatalities by asphyxiation. This research presents a numerical study of smoke spread in a large mosque. This research investigates the effect of heat release rate on the studied parameters which include visibility, smoke layer height, carbon monoxide concentration, smoke layer temperature and evacuation time as well as the effect of fire location and natural ventilation location on the same investigated parameters. Fire Dynamic Simulator (FDS) version 5.5.3 is utilized to simulate fire propagation in a 50 m long, 42 m wide and 32 m height of a large domed mosque that is divided into main hall for men and two identical floors for women. The fire is caused by an electric short circuit on ceiling air conditioners. Results shown in the paper indicated that, as a result of increasing heat release rate the tenable conditions are worsened where the visibility is reduced, carbon monoxide concentration is increased and the temperature as well increased at the human level. Therefore the evacuation time is increased with the increase of heat release rate. Also results show that changing fire location has a great effect on the studied parameters. When fire takes place at the center of the mosque the smoke spread is much more than that one when fire takes place at the corner of the mosque. Finally, the results show that the best positions of the natural vents are to be placed at the ceiling where tenable conditions are improved at the human level.

Plant based Coagulants for Point of Use Water Treatment - A Review by Bhavya K. Dwarapureddi, Vara Saritha (61-76).
Pure uncontaminated water does not occur in nature. Clean, fresh drinking water is essential to human and other life. Potable water should be free from heavy metals, turbidity, organic compounds and pathogens. Conventional treatments of water often include sedimentation, filtration and disinfection. Coagulation is one of the key process to remove colloidal particles and colour from water. The chemicals used for the process are called coagulants. Among the coagulating agents used in water treatment, ferric sulphate or alum (aluminium sulphate) is some of the most widely used salts. Aluminium is strongly neurotoxic and may be involved in the development of Alzheimer's disease. Recently, these problems calls out for a tremendous amount of research to be conducted to identify robust new methods of purifying water at lower cost and with less energy, while at the same time minimizing the use of chemicals and impact on the environment. Hence this review presents the efficiency of some natural coagulants used by humans throughout history in treating drinking water. The review concludes that natural coagulants have a bright future and would work wonders in blended form.