Duckweed, recognized for its efficiency in wastewater treatment, has been investigated for its potential to remove pollutants from pig farm biogas slurry. This study revealed the optimal concentration of biogas slurry for cultivating duckweed, offering insights important for sustainable agriculture and environmental management.
The research focused on various concentrations of biogas slurry, particularly examining the growth, biomass production, and pollutant removal capabilities of duckweed. Results indicated the 4% biogas slurry concentration to be optimal, yielding impressive removal efficiencies for several pollutants.
Under the 4% concentration, duckweed excelled with a biomass production capacity reaching 1.78 g/(d·m2) and showcased remarkable pollutant removal rates, including 54.69% for chemical oxygen demand (COD), 86.89% for total nitrogen (TN), 97.25% for ammonia nitrogen (NH3-N), and 85.22% for total phosphorus (TP). These results highlight duckweed's potential as both a wastewater treatment solution and as a protein-rich feed for livestock.
Duckweed's rapid growth and high biomass production make it particularly attractive for ecological restoration and sustainable agriculture. Historically, duckweed has garnered attention for converting wastewater nutrients to high-quality biomass suitable for livestock feed, with studies showcasing its ability to absorb excessive nitrogen and phosphorus from polluted waters.
This study aligns with earlier findings detailing how various duckweed species contribute to significant bioremediation within wastewater treatment frameworks. The results from this research reinforce the idea of integrating duckweed cultivation with livestock systems to create nutrient recycling models, thereby reducing negative environmental impacts.
Conducted at the Dongrui Food Group swine farm, the study monitored duckweed's growth over three weeks under controlled greenhouse conditions. Over this period, duckweed was cultivated with different biogas slurry concentrations, illuminating the influence of nutrient availability on its productivity and pollutant removal efficiency.
The researchers determined growth parameters such as chlorophyll content and relative growth rates, affirming the close relationship between nutrient levels and plant health. Chlorophyll content peaked at 0.84 mg/g within the optimal 4% treatment group, indicating enhanced physiological performance. When stressed by higher concentrations of biogas slurry, chlorophyll levels, along with overall biomass, decreased significantly.
The findings present valuable references for designing scalable duckweed production systems aimed at wastewater treatment. It is clear from this research how balancing nutrient supply plays a pivotal role not just for plant growth, but also for maximizing pollutant uptake.
While duckweed flourished at the 4% concentration, higher concentrations hindered its growth, underlining the significance of precision when utilizing biogas slurry for effective cultivation. Such cultivation strategies could be invaluable for farmers seeking sustainable methods to improve both crop production and environmental health.
Looking forward, the study suggests avenues for additional research to optimize duckweed's performance, particularly under varying operational conditions commonly experienced during real-world wastewater treatment applications. Enhanced knowledge on duckweed's adaptive capacities will contribute significantly to the development of economically viable bioremediation systems.
Overall, the insights from this research lay groundwork for advancing the use of duckweed as both a water purification method and as alternative feed, potentially leading to holistic solutions for agricultural sustainability and environmental preservation.