Shift of system performance and indicators of biofilm development in constructed wetland integrated with vermifilter treating synthetic rice mill wastewater
Year: 2025
Type: article
Abstract: Never been used in the remediation of rice mill wastewater (RMW), nature-based solutions, such as constructed wetland (CW) and vermifilter (VF), can be utilized to minimize the discharge of organic matter from the industry to the environment. This study employed a three-stage CW integrated with VF to treat synthetic RMW comprising recalcitrant and noxious pollutants such as lignin and phenol. Two systems were fed with synthetic RMW of COD 2000 mg/l with phenol and lignin concentrations of 10 mg/l and 150 mg/l (R1) and 20 mg/l and 150 mg/l (R2), respectively. The COD removal dropped from 92 ± 0.2 % in R1 to 82.2 ± 0.2 % in R2, and lignin from 78.4 ± 0.3 % in R1 to 74.4 ± 0.6 % in R2. The stimulation of proteins and polysaccharides in the bed media of the inlet section of R2 indicated the toxic impact of phenol, resulting in the increased synthesis of EPS as a protective shield for cells via a metabolic pathway. Biofilm batch assay revealed that the increased phenol concentration inhibited the growth of microbes, resulting in decreased biodegradation of COD from 42 ± 2 % in R1 to 29 ± 2 % in R2 and lignin from 28 ± 1.5 % in R1 to 23 ± 1.8 % in R2, respectively. This outcome was corroborated by the lesser population of heterotrophic bacteria, fungi, and actinomycetes in R2. Moreover, increasing phenol concentration reduced dehydrogenase and β-glucosidase enzyme activity by 27 % and 24 %, respectively. It also adversely affected the development of the Canna indica plant and resulted in mottling and wilting of leaves.
Authors: Sudeep Kumar Mishra, Puspendu Bhunia, Arindam Sarkar
Institution: Indian Institute of Technology Bhubaneswar
Language: English
Subfield: Waste Management and Disposal
Field: Environmental Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $3,500
OpenAlex ID: W4407870902