Overview
Heavy metals in water pose a significant health risk, with industrialization and agricultural pollution being major challenges in China. Traditional methods like chemical precipitation and ion exchange often introduce additional contaminants and require extensive consumables. Bioremediation presents a more sustainable solution, as our bacteria effectively bind heavy metals, forming carbonate precipitates that can be separated from treated water. This scalable and environmentally friendly method is well-suited for industrial wastewater treatment plants and aligns with several Sustainable Development Goals (SDGs), particularly SDG 6 (Clean Water and Sanitation), SDG 12 (Responsible Consumption and Production), SDG 14 (Life Below Water), and SDG 15 (Life on Land). To enhance the sustainability impact of our projects, we have engaged with various stakeholders, including wastewater treatment facilities, research institutes, and government environmental agencies. These collaborations have provided valuable feedback and insights, helping us identify challenges and opportunities for improvement, ultimately optimizing the project and paving the way for a sustainable future rollout.
1. Introduction
Our research team employed Escherichia coli to remove heavy metal ions from water by expressing rice metallothionein (OsMTI-1b) for metal binding and a urease gene cluster from Sporosarcina pasteurii for microbial induced calcite precipitation (MICP). Tests revealed that both OsMT1 and the urease gene cluster significantly improved the removal of Cd²⁺ and Pb²⁺. This process ensured a safer water supply, promoted ecosystem protection and human health, and supported sustainable, healthy development. We actively engaged with key stakeholders throughout the project.
2. Major Stakeholder Engagement
We engaged with stakeholders, including environmental scientists, industry leaders, and wastewater treatment plants to ensure the project aligned with real-world challenges and practical needs.
2.1 Researchers
Dr. Siqing Chen
Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Science
Marine aquaculture
By ensuring that our project tackles the most important sustainability issues facing the industry, the interview with Dr. Chen helped us to better connect with SDGs 12 (Responsible Consumption and Production) and 14 (Life Underwater).
Suggestions and conclusions:
He made the point that heavy metals in groundwater, such as iron and manganese, can harm fish development, lower their immune, and even cause illness or death. Aquaculture heavy metals endanger human health in addition to harming marine life. Finding a long-term, sustainable way to lower the number of heavy metals in the environment and lessen their negative effects on human health and undersea life is now one of the factors helping us achieve our goal.
Dr. Jinlong Jiang
Third Institute of Oceanography, Ministry of Natural Resource
Marine ecological protection and resource utilization
Dr. Jiang concentrated on the preservation of marine environments and the utilization of resources, and he raised a crucial point regarding the latter. To meet Sustainable Development Goals 6 (Clean Water and Sanitation) and 12 (Responsible Consumption and Production), we must prioritize the recycling, treatment, and reuse of wastewater in modern industrial enterprises, along with a significant reduction in the generation of wastewater pollutants.
Suggestions and conclusions:
The degree of heavy metal contamination differs from place to place, with industrial and agricultural operations being the primary causes of pollution in certain places. The key to addressing heavy metal pollution is prevention at the source. To reduce the spread of pollution, industrial businesses need to improve wastewater collection and treatment. This indicates the course of our efforts.
2.2 Industry
Mr. Jining Cheng
China Coal Xi'an Design Engineering Co., Ltd.
Technical Director
Mr. Cheng stated that chemical precipitation is the most commonly used method due to its low cost and high efficiency. In contrast, current biological treatment methods have drawbacks, such as the need for additional nutrients and low efficiency. While there is no perfect heavy metal treatment technology, we think bioremediation is the way of the future because it provides a safer, more sustainable, and ecologically beneficial solution. Aligned with SDG 12(Responsible Consumption and Production).
Suggestions and conclusions:
There are four primary methods for heavy metal removal from water: chemical precipitation and coagulation, reverse osmosis, electrochemical techniques, and biological treatment. Chemical precipitation forms metal precipitates but may introduce pollutants like aluminum. Ion exchange and adsorption use materials like resin but have limited capacity. Electrochemical methods are energy-intensive, while bioremediation depends on environmental factors.
Ms. Ruan Mengfei
Zhejiang Aquatic Seed Industry Ltd., Co.
General Manager
In an interview with Ruan Mengfei, General Manager of Zhejiang Aquaculture Seed Industry, she also spoke favorably of the technology's ability to remove heavy metals. According to her, aquaculture can benefit from clean water and become a sustainable industry that satisfies SDGs 12 (Responsible Consumption and Production), 14 (Underwater Life), and 15 (Terrestrial Life) through continuous production.
Suggestions and conclusions:
She said that before the water in cesspools reaches the rivers, heavy metals won't be there thanks to technology. The ecological functions of heavy metal and toxin-filled rivers will be restored, and more freshwater resources will be available for freshwater aquaculture. This will make the aquaculture sector a healthy and sustainable model for production and development, increasing yield and product diversification and dynamism. Over an extended period, there are noteworthy financial advantages. The greater diversity of efficient aquaculture systems and production will enable consumers to buy more environmentally friendly and healthful products, which will have a positive impact on society.
2.3 Water treatment plants
Ms. Sha Yu
No. 1 Water Treatment Plant, Xianyang Water Group Co., Ltd.
General Manager
Ms. Yu was aware of every crucial detail about the water treatment plant's process for treating tap water in her capacity as manager. She pointed out that it is important to routinely check the water supply to make sure it satisfies safety requirements before using it. Minimize their detrimental effects on the environment and human health in accordance with SDG 14 (life underwater).
According to her, testing is done at the plant, across the distribution network, and at the customer's location once a month for heavy metals and regular contaminants. Additionally, every six months, emergency groundwater supplies are checked to make sure they still fulfill safety requirements before being used. She pointed out that there are no specialized heavy metal removal facilities in the typical water treatment plants that provide tap water, and she highlighted that heavy metals primarily originate from industrial sources and should be dealt with inside the industrial system. leading the way to our scenarios for application.
Mr. Shuicai Xu
Deqing County Water Treatment Office
Inspection and Evaluation Team Leader
We interviewed Mr. Xu, the Inspection and Evaluation Team Leader of Deqing County Water Treatment Office. He led us to a wastewater treatment plant in Deqing. He suggested that wastewater treatment benefits the environment and attracts tourists through a clean water environment, thus boosting the local economy, in line with SDG 6 (clean water and sanitation) and SDG 12 (responsible consumption and production).
Suggestions and conclusions:
Inspired by wastewater treatment plants, we designed a setup consisting of a reaction tank, which is used to allow bacteria to bind to heavy metal ions and produce MICP, and a separation tank, which is used to coagulate the bacteria and heavy metal precipitates and remove them from the water. See more details in Hardware https://2024.igem.wiki/hangzhou-sdg/hardware.
Mr. Hangshuai Liu
Dawang Wastewater Treatment Plant, Xixian New Area, Shanxi
Technician
Mr Liu, as a technician, made important comments on the safety of residual bacteria. And, he said that the adsorption of heavy metals by bacteria is an environmentally sustainable method, especially suitable for pre-treatment. Consistent with SDG 12.
Suggestions and conclusions:
Wastewater treatment involves screening, sedimentation, biological treatment, advanced treatment, and disinfection. In the secondary sedimentation tank, solid-liquid separation is enhanced by coagulants, followed by sterilization with sodium hypochlorite to target E. coli. We decided to add a UV lamp after the separation tank to kill most bacteria and further test and improve the hardware. Research is ongoing to improve bacterial adsorption by studying environmental factors such as pH and nutrient needs.
2.5 Public activities
The results of the public survey show that although there is some uncertainty (9-10 percent of people are not sure), the majority of people still recognize the importance of the issue. In addition, most people believe that heavy metal pollution is closely related to human life, with 86 percent recognizing that heavy metal pollution is closely related to human life. In short, consumers are eager to see heavy metal pollution dealt with. See HP https://2024.igem.wiki/hangzhou-sdg/human-practices
for more details.
Hangzhou-SDG organized educational events to promote public awareness of sustainably reducing heavy metal pollution among primary and secondary school students.
We produced comic brochures that highlight the urgent need for solutions to heavy metal pollution in water. These brochures were distributed during educational events to introduce the public to the project using genetically engineered E. coli for heavy metal removal. The comic format simplifies complex biotechnological concepts, making them accessible to people from diverse backgrounds. This approach effectively raised awareness, fostered public support for pollution control, and built trust in environmental technologies.
3. The impact of our project
Based on feedback from stakeholders and the public, our project provides a sustainable solution that is safer and more environmentally friendly to meet the challenges posed by heavy metal pollution. The present experimental data showed that the strain OsMT1-Ure expressing both genes showed the best overall performance, with OsMT1 being more effective at lower concentrations and the urease gene cluster being more effective at higher concentrations, with maximum removal of 85.78% for cadmium and 98.98% for lead. Our modified DH5α strain is scalable and environmentally friendly, which contributes to the achievement of multiple Sustainable Development Goals (SDGs).
A. Removal rates of Cd²⁺ by E. coli; B. Removal rates of Pb²⁺ by E. coli. “N/A” stands for “not applicable.”
SDG6: Clean water and sanitation
6.1 Access to safe and affordable drinking water
The engineered bacteria in our project bind to heavy metals in the water and induce the formation of carbonate precipitates, allowing the bacteria and precipitates to be easily separated from the treated water. This approach provides a scalable, more environmentally friendly alternative to traditional methods and helps ensure a safer water supply.
6.3 Improve water quality: Reduce pollution, eliminate waste dumping, minimize the release of hazardous chemicals and materials, halve the proportion of untreated wastewater, and significantly increase global waste recycling and safe reuse.
Our project aims to strengthen the wastewater recycling and treatment chain of industrial enterprises to reduce the spread of pollution. And, we designed a unit to treat industrially generated wastewater, consisting of a reaction tank, which is used to bind bacteria to heavy metal ions and produce MICP, and a settling tank, which is used to coagulate the bacteria and heavy metal precipitates and remove them from the water. This further reduces the discharge of untreated wastewater and reduces environmental pollution.
SDG 12: Responsible consumption and production
12.3 Reducing food losses in the production and supply chain.
Our project improves water cleanliness by reducing heavy metal pollution. Reducing heavy metals such as manganese and iron in groundwater affects fish growth and reduces the chances of fish becoming sick or dying. As a result, food losses are reduced at all points in the aquaculture supply chain, thereby helping to reduce global food waste.
12.4 Achieve the environmentally sound management of chemicals and all wastes throughout their life cycle, reducing their release into the atmosphere and their leakage into water and soil and minimizing their negative impact on human health and the environment.
Minimize the negative impacts of chemicals and all wastes on human health and the environment by strengthening the wastewater treatment chain in industrial enterprises, reducing the discharge of untreated wastewater into the ecosystem, and protecting the ecosystem.
12.5 Waste generation is significantly reduced through prevention, abatement, recycling, and reuse.
Our specially designed bacteria attach themselves to heavy metals in water and cause carbonate precipitates to form, which makes it simple to remove the precipitates and bacteria from the treated water. These modified bacteria are developed for usage in locations requiring heavy metal cleanup, such as industrial wastewater treatment plants. This strategy helps to guarantee a safer water supply by offering a scalable, sustainable, and ecologically friendly substitute for conventional techniques.
SDG14 Life Below Water
14.1 Prevent and significantly reduce all types of marine pollution, especially from land-based activities.
Pollution from industrialization and agriculture is a major problem in China. Heavy metals such as lead, mercury, cadmium, and chromium occur naturally but are released into the environment through industrial activities, mining, and waste disposal. Marine pollution can be prevented and significantly reduced by strengthening the wastewater treatment chain of industrial enterprises, reducing the release of untreated wastewater into the environment, and reducing pollution from land-based activities.
14.2 Sustainably manage and coastal ecosystems to avoid significant negative impacts and take action to help them return to their original state and remain healthy and productive.
With our technology, heavy metal contaminated water will not contain heavy metals before it reaches the river. Rivers containing heavy metals and toxins will regain their ecological function and provide more freshwater resources for freshwater aquaculture, leading to sustainable and healthy patterns of production and development in the aquaculture sector, enhanced yields and product diversification, and a more vibrant aquaculture industry.
SDG15：Life on Land
15.1 Protect, restore and sustainably utilize terrestrial and inland freshwater ecosystems and their services.
Through our bioremediation technology, the maximum removal rate of cadmium reaches 85.78 percent and the maximum removal rate of lead reaches 98.98 percent. This will enable the rivers originally polluted by heavy metals to regain their ecological functions and achieve the protection and sustainable use of freshwater ecosystems and their services.
4. Long-Term Impact and Monitoring
We prioritize both the environmental and social impact of our project. Therefore, it is essential to consider various social factors to ensure a lasting and meaningful impact.
4.1 Regulations of GMOs in China
This project adheres to Chinese environmental guidelines and international sustainability frameworks, aligning with the Sustainable Development Goals (SDGs) for clean water and environmental protection.
The approval process of GMOs in China involves three trial stages: intermediate test, environmental release test, and production test, as outlined in the Biosecurity Law and the 2016 Measures for the Safety Evaluation of Agricultural GMOs. During each stage, factors like genetic stability, toxicity, spread, and non-target impacts are assessed.
After completing trials, submission of the Application for the Safety Evaluation of Agricultural GMOs to the relevant authorities is required, and if approved, the Ministry of Agriculture and Rural Affairs will issue a safety certificate. See Human Practices https://2024.igem.wiki/hangzhou-sdg/human-practices for more details.
4.2 Assessment Methods
To effectively minimize pollution, enhance water quality, and improve environmental sustainability, we have set comprehensive goals over the next five years. Progress will be evaluated through regular quarterly, annual, and final assessments. These goals are designed to align with both national policies on sustainability and international environmental initiatives.
First, we will continuously monitor the levels of heavy metals in water, ensuring compliance with Chinese environmental regulations and global water quality standards. This will allow us to track and manage the pollutants effectively.
Additionally, the bioremediation capabilities of the bacteria will undergo consistent testing to confirm its ability to bind and remove heavy metals, making sure that the process adheres to international safety and environmental standards.
Alongside this, regular water quality assessments will be conducted, ensuring that our project complies with national environmental laws while contributing to broader global sustainability goals.
Lastly, we will gather and analyze data on resource efficiency and waste management to ensure alignment with China’s Circular Economy Promotion Law and relevant international guidelines.
4.3 Goals
In the short term, within the first year, we aim to complete the development of the bacterial strain and conduct initial tests of its bioremediation efficiency. We will also initiate the review process to guarantee the project complies with China’s biosecurity laws and meets ecological safety standards.
In the medium term, over the next two to three years, we plan to roll out the system in industrial environments, to incorporate our bacteria and hardware in local wastewater treatment plants. During this period, we will also secure the necessary certifications to meet Chinese environmental laws.
Looking further ahead, in the long term, spanning four to five years, we aim for full adoption of the system, introducing our system to all wastewater treatment plants and making a significant positive environmental impact. Transparent labeling of products containing genetically modified organisms will be a priority to build consumer trust.
4.4 Implementation Phases
The implementation will begin with the development and validation of the bacterial strain, focusing on its ability to bind heavy metals and precipitate them from the water.
Afterward, small-scale trials will be conducted in controlled environments to confirm the system’s effectiveness. Once these trials prove successful, we will perform the necessary safety tests to comply with China’s biosecurity regulations.
The third phase involves submitting the product for regulatory approval to obtain the production licenses required by China's environmental protection laws.
In the following phase, we will expand trials to larger, real-world industrial wastewater treatment facilities, ensuring continuous monitoring of water quality and the reduction of heavy metal levels.
Finally, we will optimize the system based on trial data, preparing for widespread industrial-scale implementation.
4.5 Possible Barriers and Strategies
Technical hurdles may arise, particularly in the fine-tuning of bioremediation processes. To address these challenges, we will work closely with academic research institutions, ensuring we have access to the latest technological support.
Financial constraints could also present challenges, but we plan to seek funding from government environmental programs and build partnerships with relevant industrial stakeholders.
Lastly, market acceptance is crucial for the success of genetically modified microorganisms in aquaculture. To ensure this, we will engage in public education efforts and form collaborations with environmental agencies to build awareness and foster trust in the sustainability of our bioremediation approach.
References
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Qasem, N. A. A., Mohammed, R. H., & Lawal, D. U. (2021). Removal of heavy metal ions from wastewater: a comprehensive and critical review. npj Clean Water, 4(1), 36. https://doi.org/10.1038/s41545-021-00127-0