RESUMEN
Nowadays to cope-up with the emerging global clean-water crisis, wastewater needs to be remediated properly to be used as an alternative source. Here a cost-effective approach has been taken to treat heavily-polluted (BOD-1234.33 mg L-1, COD-1706.64 mg L-1, TDS-6984 mg L-1, and sulfide-140.8 mg L-1 ammonium-134.5 mg L-1) Tannery Waste Water (TWW). Three cyanobacteria were (Arthrospira platensis, Leptolyngbyavalderiana, and Anabaenasphaerica) used as bio-reagents in pilot-scale treatment. Wastewater remediation-potential and biomass-generation capacity were evaluated in various TWW concentrations. The maximum biomass growth and the highest pollution removal percentage was observed when exposed to 50% TWW; although among the tested strain, Arthrospira and Leptolyngbya performed better than Anabaena by showing greater pollution removal potential (BOD 93%, COD 94%, sulfide 99%, ammonium 93%) in one hand and higher biomass production rate (100 mg L-1 Day-1) on the other. DO was increased noticeably by 10-15-fold. Morphological characterizations of tannery wastewater exposed Anabaena revealed unusual thick sheath formation, along with heterocyst and akinete formation in their trichome. Biochemical characterizations of remediating cyanobacteria showed presence of wastewater-accumulated nutrients (N, P, K). Nutrient-loaded biomass improved growth of rice and chickpea seedlings when used as a growth promoter. These facts have been illustrated by factor analysis and discriminant analysis. Cyanobacteria-mediated pilot-scale tannery wastewater treatment would create ecologically and economically-sustainable technology for clean-water production. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03712-x.
RESUMEN
Wastewater Treatment Pond (WTP) is an effective remediation technology for economically developing nations. Although it's excessive organic and nutrient loads with higher water logging time triggers mixed and unprofitable microalgal mats. This may serve as a seeding source for Cyanobacterial bloom in receiving waterbodies. Since, to maintain the growth of desirable algal species in WTPs, understanding towards environmental regulation and algal mat composition is important, especially for tropical countries, like India. In this study, biological treatment pond (BTP) and outlet pond (OP), of a tannery effluent treatment plant in eastern coast of India, were chosen for surveying the algal community composition concerning ecological parameters. Nearly, both the ponds were polluted, but the diversity was lower in BTP due to its elevated nutrient content (Ammonia 173 mg L-1) and higher persistent organic matters (COD 301.7 mg L-1) than OP. Using canonical correspondence analysis, seasonal variations showed higher species abundance during early summer compared to other seasons. A total of 37 taxa forming thick algal mats were recorded. The matrix of mats was mainly composed of Cyanobacterial members such as Phormidium, Leptolyngbya, Spirulina, and Pseudanabaena, followed by diatoms, especially Amphora and Nitzschia. Diatoms commonly occurred as embedded component in the entangled matrix of blue-green algal filaments. Hierarchical cluster analysis was employed to group all these taxa based on their seasonal appearance and abundance. This year-long intensive study revealing seasonal algal mat composition patterns in these WTPs will ultimately safeguard the livelihood and security of adjoining localities through proper site-specific pollution control.
