Waste water to Energy! New road to Biofuels.
By: Faiyz Uddin Khawaja
Tags: Biofuels, Power, Energy, Wastewater, Renewable Energy

Fossil fuel dependence in Pakistan is a huge issue. The Energy Mix of Pakistan 2013, indicated this figure as high as 65.9% which only reduced to 62.6% in 5 years. This dependence is not only bad for Pakistan’s economy but it is worse for our environment.

Pakistan Energy Mix; Express Tribune Projections

TED talk by Jonathan Trent highlights sustainable possibilities using waste water to grow Algae for bio fuel production.

Jonathan Trent at TED talk

Mr. Trent a biofuel researcher, connected with NASA talks about a system to grow algae and to harvest them for biofuel manufacturing mainly for transportation and as an alternate to fossil fuel. For this system to operate wastewater is need to be collected from waste water treatment plants, and fill plastic pods/ containers with water and microalgae. The pods or special containers would provide continual CO2 for algae to consume and hence thrive, encouraging their growth. Skilled employees would also flow the fluid and algae through a special setup of pipes that would harvest any oxygen produced by the algae, and allow the algae to accumulate and settle in a collection container. These algae that settled in the container can be harvested for biofuel production.

Implementing the biofuel generation using waste water complies to the Sustainable Development Goal 7 & 13 i.e. Affordable and clean energy and Climate Change. City of Lights, Karachi has three Primary Waste water Filtration plants and another one is being built in DHA.

Karachi Sewage water treatment plants

This site is most suitable for the design and implementation of this alternate source of energy. In its mechanics, Waste water along with some source of CO2 is pumped into the floating structure and the waste water provides nutrients for the algae to grow and thrive and they sequester CO2 that would otherwise go off into the atmosphere as a greenhouse gas hence also acting as the CO2 sinks, i.e. playing the part in combating global warming issue. Solar energy from sun is used to grow the alae and the wave energy on the surface provides energy for mixing the algae and the temperature is controlled by the surrounding water temperature. The algae that grow produce oxygen. This oxygen can be released into the air or can be stored for other uses such as to be used in Hospitals, critical care units and other chemical industries. The system combined all the technologies is sustainable and is also contained what do I mean by that it’s modular let’s say something happens that’s totally unexpected to one of the modules let’s say, for example, it leaks struck by lightning the wastewater that leaks out is the ocean water that already now goes into that coastal environment and the algae that leaked out is biodegradable and because they’re living in wastewater they’re freshwater algae which means they can’t live in salt water so they die. The plastic is something with which we are quite familiar and we have good experience with it so we’ll rebuild our modules to be able to use them again so we may be able to go beyond that when thinking about this system.

Other thing to consider is the structure itself as it will provide a surface for things in the ocean and this surface which is covered by seaweeds and other organisms in the ocean will become enhance marine habitat so it increases biodiversity and finally because it’s an offshore structure we can think in terms of how it might contribute to an aquaculture activity. Furthermore, other alternate and renewable energy resources can be combined to form a more yieldable infrastructure. Other technologies that can be integrated with this system can be off-shore solar, mini wind turbines, wave energy harvestings and so on so forth.

Results by the experimental setup of this infrastructure using the help of laboratories in santa cruz at the California revealed promising outcomes. Karachi being the major city with limitless supply of waste water and a coast for us to exploit can result positively. One huge factor in support of this biofuel is that our vehicles does not require much changes in their engines to be done to use this biofuel as replacement of conventional fossil fuel. Such practices are common in brazil where biofuel is mixed with conventional fuel to be used in existing transport system. Possibilities are endless with this future fuel i.e. biofuel.