There are numerous opportunities to utilize microbes for the treatment and management of industrial wastewater.
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The creepy crawlies that can clean industrial wastewater

Wastewater from industrial activities contains pollutants that harm the environment. Microbes play a crucial role in cleaning this wastewater through biodegradation processes.

Wastewater generated by industrial activities poses a significant environmental concern. The wastewater from industrial processes often contains elevated levels of pollutants such as heavy metals, organic compounds, chemicals, and toxic substances. Pollution arises when untreated or insufficiently treated wastewater is discharged into rivers, lakes, or oceans. Consequently, aquatic life can experience adverse effects, ecosystems can be disrupted, and humans can be exposed to unsafe water. Soil fertility may also be affected, and organisms and plants can suffer harm due to pollutants in wastewater.

Individuals who consume contaminated food, drink contaminated water, or come into contact with it may experience gastrointestinal issues, skin diseases, respiratory disorders, or long-term cancer risks. Microbes play a crucial role in the treatment and reclamation of industrial wastewater. Microbial communities facilitate the biodegradation of industrial wastewater by employing biodegradation processes. Certain bacteria and fungi produce enzymes that break down complex organic molecules. To effectively manage microbial communities in industrial wastewater treatment systems, monitoring microbial populations, maintaining optimal environmental conditions, and providing suitable carbon and nutrient sources are crucial. Harnessing microbial communities can enhance water quality and environmental protection by optimizing wastewater treatment processes, ensuring effective and sustainable removal of pollutants.

Microbial habitat in wastewater

Industrial wastewater treatment systems rely on microbial communities for nutrient cycling. Nitrification converts ammonia into nitrate, while denitrification converts nitrate back into nitrogen gas. Biofilms, which consist of microorganisms embedded in a matrix of extracellular substances, are highly prevalent in industrial wastewater. In wastewater treatment systems, biofilms can develop on surfaces such as pipes, tanks, and filters. Microbial communities in industrial wastewater treatment systems often exhibit synergistic interactions, with different microorganisms working together to enhance treatment efficiency. Enzymes produced by certain microorganisms can degrade complex pollutants, while others can utilize simpler compounds as substrates.

Credit. Midjourney generated

Environmental factors and fluctuations in pollutant concentrations can influence microbial communities in industrial wastewater treatment systems. These communities possess the ability to adapt to varying operating conditions while maintaining their treatment performance. To optimize treatment processes, it is essential to comprehend the composition and dynamics of microbial communities in industrial wastewater treatment systems. With this knowledge, we can devise strategies to manipulate microbial communities and engineer them for maximum efficacy.

Application of microbes in wastewater detoxification

Bacteria and fungi, among other microorganisms, possess enzymes capable of breaking down complex organic compounds commonly found in wastewater. These microorganisms convert organic pollutants into simpler, less toxic forms. Biological processes are responsible for the removal of nutrients like nitrogen and phosphorus from wastewater. Additionally, polyphosphate-accumulating bacteria (PAOs) can remove phosphorus from the environment by storing it as insoluble compounds. These microbial processes help maintain water quality and prevent eutrophication. In many industrial processes, metal ions and heavy metals are often present in industrial wastewater. Microbes can interact with these metals, transforming them into less toxic or insoluble forms.

Figure 1. Schematic representation of wastewater treatment
Credit. Author

Microbes can also detoxify contaminants and hazardous compounds resistant to conventional degradation methods. Specific enzymes known as oxygenases can break down biological contaminants such as polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs). Biofilm-based treatment systems like trickling filters and rotating biological contactors effectively harness microbial communities to degrade and remove pollutants from wastewater. Microbial fuel cells (MFCs) provide another innovative approach, treating wastewater while generating electricity as a by-product. In MFCs, microorganisms oxidize organic matter in wastewater, transferring electrons to an electrode and producing electricity. Understanding microbial communities’ diversity and functional roles is crucial to optimize wastewater treatment processes and develop sustainable approaches to wastewater management.

Challenges and opportunities

Industrial wastewater contains a complex mixture of pollutants, chemicals, and contaminants. The diversity of microorganisms presents a challenge for microbial treatment as different microorganisms prefer specific compounds. Selecting and maintaining a microbial community that can effectively degrade the specific pollutants in industrial wastewater can be difficult. When high concentrations of heavy metals, toxic chemicals, or biocides are present, microorganisms that degrade pollutants become less effective.

Ensuring stable and active microbial activity in industrial wastewater treatment processes is challenging. Changes in pH, temperature, and nutrient availability within the wastewater can disrupt the microbial community and reduce treatment efficiency. Competition and predation among microbial communities can occur in industrial wastewater treatment systems, leading to shifts in community composition and a decline in treatment efficiency as microorganisms compete for resources.

Scaling up microbial wastewater treatment processes from laboratory studies to full-scale implementation can be challenging. Careful consideration of factors such as reactor design, flow rates, and mass transfer limitations is necessary to ensure the efficient distribution of microbes and optimal treatment outcomes. Microbial treatment technologies must also address regulatory requirements and gain public acceptance before widespread adoption. Advancements in microbial monitoring, genetic engineering, and synthetic biology hold promise for improving industrial wastewater microbial treatment processes.

Conclusions

There are numerous opportunities to utilize microbes to treat and manage industrial wastewater. The capacity of microbes to degrade pollutants contributes to improved water quality. Microbes exhibit a highly diverse and versatile range of metabolic capabilities. Wastewater treatment processes that employ microbes offer the potential for energy recovery. Microbial fuel cells (MFCs) can break down organic matter in wastewater while simultaneously generating electricity as a by-product. This approach enables wastewater treatment and renewable energy production, presenting a sustainable and cost-effective solution.

Microbial treatment methods often prove more cost-effective when compared to conventional treatment approaches. Microbes can function under mild conditions, reducing the requirement for expensive infrastructure and energy-intensive processes. By utilizing microbial treatment, the reliance on harsh chemicals and energy-intensive methods can be minimized, thus lowering the carbon footprint and environmental impact of wastewater treatment. Ongoing research and development efforts are focused on optimizing microbial processes, exploring new microbial species, and developing innovative treatment technologies to maximize the benefits of microbes in industrial wastewater treatment.

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Journal reference

Sharma, P. (2021). Efficiency of bacteria and bacterial assisted phytoremediation of heavy metals: an update. Bioresource Technology328, 124835. https://doi.org/10.1016/j.biortech.2021.124835

Dr. Sharma is a Postdoctoral Research Scientist at the National University of Singapore specializing in waste/wastewater management through the use of microbes to achieve sustainable pollution management. Her expertise lies in microbial strategies, particularly anaerobic digestion/reactor, which can generate biogas as a renewable energy source. She obtained her Ph.D. in Environmental Microbiology from India in 2020. Her exceptional research contributions have earned her national and international acclaim, including prestigious awards such as the "Young Scientist Medal" from the International Society of Environmental Botanists (ISEB), CSIR-NBRI, India, the Best Paper Award from NKUST, Taiwan, and the Federation of European Microbiological Societies (FEMS) Travel Grant Award for Hamburg, Germany, in 2023.