Preface

In 2016, the global annual mean atmospheric CO₂ concentration exceeded 4000 ppm, which is more than 40 % above pre-industrial level. Water bodies taking up 0.8-0.9 bn tonnes of CO₂ each year, releasing hydrogen ions through the following equation:

The study also reveals that the surface pH reduced from 8.11 to below 8.06, corresponds to an approximately 30 % increase in water acidity. Thus, deacidifying freshwater or ocean water could be one of the major issues to tackle during these times. One approaching way could be using synthetic method, where we input deacidifying pump into the E.coli, allowing protons in surroundings to be absorbed, which implements a deacidification ability to the water environment.

Target users

Our target users are people who benefit from water deacidification, including water treatment industry practitioners, some farmers and local residents. Our modified E.coli with the H⁺ inward pump will be settled in a device and designed to function in an acidic water source. This device consists of three main parts, the water purification tube that holds the bacteria, the polluted water source tank, and the water tank that is used to exchange the H⁺ from the polluted water source. By using the device, we can reduce the level of H⁺ in water sources and attenuate ecological hazards.

People requiring water deacidificaiton could be farmers who hope to culture water plants using freshwater/ seawater. In such case, our system can be implemented in their water culturing system to help regulate the pH level of the water. In addition, it could also be implanted in hydroponic water systems for farmers or even households in a sustainable way.

Safety Concerns

Biological leakage is a major concern for our products. In our project, the device we design can prevent leakage of bacteria to a large extent. Even though the bacteria go into the environment due to emergency, they can not survive long as they constantly and passively absorb H⁺ into intracellular space. If our project is successful and permitted to real industrial usage, we will remove our engineered modified bacteria by applying UV light. The suicide mechanism and complete removal of the modified E.coli will prevent them from being released into the environment.

Challenge

The deacidification system we are making is an application of new gene-modified organisms, which might cause negative responses from some users. In the interviews with the manager from the DSPA WasteWater Treatment Plant, he suggested that implementing gene-modified organisms may require large sum of budgets and cause antipathy from residents, dissuading people from using our products in their deacidification system. Meanwhile, farmers and hydroponic users may not try to use such a newly-developed system they are not familiar with. Therefore, trying our best to reduce the cost and eliminating such kinds of stereotype are the main challenges in popularizing our products.

To sum up, besides letting the target users know the benefits of our system, dispelling their concerns about genetically modified organisms (GMO) products is also a challenge we need to solve, so that our products will have a better development.