Sharif Digital Repository

In this project, performance of anaerobic digestion of organic waste in liquid phase has been investigated in an experimental process. Thus, the objective of this study was to optimize the organic loading rates, temperature and mixing of anaerobic digestion to the treatment of municipal solid wastes. To achieve this, the pilot scale experiment was conducted in 70l, fully mixed reactor. The start-up process was established over a period of 2 months. Starting the digestion in two stages was done with two different feed stocks, in which the feed stock of the first stage was star and in the second stage vegetables were considered as the organic waste. Experiment was investigated in mesophilic... 

Nowdays much of the organic solid waste and wastewater is buried using centralized and traditional methods. This leads to many problems, including groundwater pollution, methane emissions into the atmosphere and rapid transmission of disease. In order to avoid these problems, using a decentralized approach can be a good solution. In this study, recovery of organic waste and wastewater of residential buildings using anaerobic digester as a decentralized way, have been examined. Using experiments, the optimum mass ratio of organic solid waste and wastewater is obtained as 80% and 20% respectively. Biogas production model is developed using mass balance and Balance of electrons in redox... 

Wastewater treatment plants play an important role within the urban water cycle in protecting receiving waters from untreated discharges. In the developed and developing countries, Energy consumption of these units are 3 and 5 % of the electrical energy demand, respectively. As far as sustainable development is concerned, not only the reduction of WWTP’s energy consumption is mandatory, but also these units should produce energy. To this end, several techniques are available namely: energy audits, replacement of equipment and improvement of process efficiency. Moreover, Energy can be generated by converting biogas -from anaerobic digesters- to heat and power. Todays, Biogas is well-known as... 

In recent years, access to clean energy sources is the major instruments for sustainable development. Limitation of energy resources and the problems resulting from the use of fossil fuels was caused attention to biomass in different countries as a stable source of renewable energy. Organic waste in municipal solid waste and domestic wastewater are biomasses that can be used as a raw material used in the production of energy. Practical studies show that quality and quantity of municipal solid waste to produce biogas and bioethanol in Iran is very appropriate. In this process, the household solid waste and wastewater are in the anaerobic digestion reactors and fermentation systems without any... 

With the growing development of urban communities and population, the demand for water and treated sewage water has grown significantly. The environmental damage of polluted water has resulted in passing of new and strict environmental laws on wastewater discharge recently. In the present research, a hybrid system involving a power, heat and cool cogeneration and a carbon dioxide capture system has been designed for a typical wastewater treatment plant. The plant is optimized from economic and environmental criteria. The anaerobic digester is modeled using the ADM1 model. The biogas is directed into the hydrogen sulfide removal filter to remove the impurities and into the heat exchanger to... 

Improper management and inefficient methods such as direct disposal to the environment to stabilize municipal solid waste and sewage sludge in addition to creating environmental problems due to the existence of food cycles, will also cause problems on human health. In this study, a hybrid system is modeled to produce value added in the form of energy and nutrients from a combination of food waste and secondary sewage sludge. This system has 3 subsystems, two-stage anaerobic digestion process that will be accompanied by the production of your bios (hydrogen + methane), the process of recovery of phosphorus from the sludge out of the digestion process and the system of simultaneous production... 

Various solutions exist for managing the waste generated in the food industry, providing opportunities for industrial symbiosis. The objective of this project is to identify and economically evaluate these solutions for material and heat recovery in the dairy, sugar, and tomato paste industries. Quantities and qualities of the generated waste in the selected industries were first identified. Subsequently, opportunities for waste management were explored. The overall structure of each solution was then modeled, and economic variables such as costs and income in each opportunity were calculated. Economic indicators, including payback period, net present value, internal rate of return, return...