As the semester kicks into full swing, more parts have started arriving, and we’ve begun testing, refining our designs, and more testing.
First up, our temperature sensors, courtesy of Sparkfun. This is a simple, robust design that will start the drum rotating once temperature reaches a certain threshold.
And of course, our Arduino Uno R3 that will be the brain of our entire system. Mouad and I have been working very closely together to set the groundwork for the power-control interface.
And finally, magnetic pickups that will be part of our safety system, to make sure the system can’t run when the drum door is open.
More parts are coming every week, and we just finished our Critical Design Review last week. Stay tuned for more about that!
Did you ever deal with ‘toothy’ stuff… Braces? Fillings? Crowns? Implants? Root canal? A trip to the dentist is usually not looked forward to with much enthusiasm – more like trepidation. But – did you ever stop to think about the effects of our oral hygiene on the rest of the planet? Maybe Mother Earth is as frightened of the sound of a dentist’s drill as humans are – and possibly with good reason!
Dental Recycling International (DRI) announced that it has partnered with the Rwanda Dental Association. DRI provides education on and technology for dental waste recycling throughout the world, and will help the association to reduce the amount of mercury from dental amalgam entering the local environment. Take a look at related articles found linked at the bottom of the posting. There’s a great piece on amalgam alternatives, with credits to U Illinois, too.
And check out Dental Recycling International (DRI) while you’re at it!
According to the World Health Organization (WHO), air pollution is now the biggest global environmental killer. Poor air quality can cause people to die early due to strokes, heart conditions, cancer, and other health issues and it’s taking a toll on our children.
University of California – Riverside’s Bourns College of Engineering students have calculated that for the low cost of $5.00, your home could be transformed into a smog-eating house that could eliminate pollution-causing nitrogen oxides from the air just by sitting there. They have determined that a coating of titanium dioxide (TiO2) costing about $5.00 on a typical home’s roof would remove the nitrogen oxides emitted by a car driven 11,000 miles yearly. Read more…
Some cities around the world have also tackled this problem with air quality, using truly advanced technological solutions.
Wouldn’t it be a great to be on the leading edge of this revolution to clean our air!
The treatment system that we have developed to treat wastes and generate energy and fertilizer uses several processes including anaerobic digestion (AD), struvite precipitation, and ion exchange. AD is a method of treating waste that has the significant advantage of allowing for energy recovery in the form of methane. This methane represents a renewable form of energy, which can be used for a variety of applications including cooking, heating, or co-generation of electricity and can also contribute to the energy requirements of operating the AD system. AD also helps avoid the negative environmental effects of improperly managed waste, such as odor problems, attraction of insects and rodents, release of pathogens, contamination of surface water and ground water, and catastrophic spills. When treated waste leaves AD, the solid and liquid portions can be separated to allow for recovery of the stabilized biosolids, which can be used as fertilizer. Biosolids application is possible because of stabilization of organic matter during AD and reduction of pathogens. The liquid portion of the waste, however, still contains high levels of nutrients such as nitrogen (N) and phosphorus (P) that require further treatment.
Recovery of struvite (MgNH4PO4·6H2O) represents a viable option for removal of both N and P from AD effluent supernatant, while also allowing for recovery of the valuable nutrients in the form of a usable and saleable solid fertilizer. This recovery likewise reduces the pressure of demands for non-renewable P resources. Struvite precipitation is usually achieved by magnesium addition and raising solution pH to force supersaturation. This unique application can potentially provide significant advantages because anaerobic digestion (AD) allows for release of nutrients into solution, thereby making them more accessible for recovery as a valuable fertilizer through precipitation.
While struvite precipitation is expected to remove a large portion of the P, only a small portion of the dissolved N in solution is removed. The remainder of soluble N, therefore, requires treatment. Use of ion exchange (IX) onto natural zeolites to remove N from AD centrate avoids many of the disadvantages of biological nutrient removal (BNR) systems. IX also allows for recovery of the N via adsorption onto zeolite followed by field application of the N-rich zeolite material as a fertilizer.
For our growth study we will be using a variety of analytical methods to evaluate the plant growth and leaching of nutrients from the soil, such as wet chemical methods, plant tissues testing, and ion chromatography (IC). IC samples are filtered using Fisher brand 0.45μm syringe filters and assessed using a Metrohm 881 Compact IC pro. The standards used for the IC analysis include concentrations of 1.0, 2.5, 5.0, 15, 50, and 100 mg/l for all ions and the cation eluent consisted of 1.7 mM nitric acid and 0.7 mM dipicolinic acid (pyridine-2,6-dicarboxylic acid).
The elemental evaluation will be performed using equipment at the Nanotechnology Research and Education Center (NREC) at the University of South Florida. SEM-EDX will be performed using a Hitachi S800 (Naka, Japan) for SEM with an EDAX Phoenix Pro (Mahwah, NJ) for EDX. Samples will be mounted on carbon tape fixed on an aluminum mount. The imaging and EDX is performed using EDAX Genesis software. A ZAF correction is used for quantification of EDX results.