الفهرس | Only 14 pages are availabe for public view |
Abstract In the present study, the possibility of growing cyanobacteria in wastewaters from olive oil production (OMW) and potatoes industry (PIW) was investigated. Nostoc muscorum, Anabaena oryzae and Spirulina platensis were chosen as three blue-green algae for the present study. The three cyanobacteria were cultivated over 30 days period on olive effluent (OMW), diluted effluent (OMW 50%) and PIW. The growth of the three strains was achieved in the three media as indicated by their total chlorophyll, optical density and biomass dry weight. The initial phenols concentration in OMW wastewater was reduced by 50-60% in 15 days, and more than 80% of phenols were removed by day 30. The cyanobacteria grown on wastewater were formulated into biofertilizers and were applied on a sandy soil to grow celery and lettuce plants under different replacement levels (25, 50 and 75%) of the recommended chemical fertilizers, while the control did not receive any fertilizers in a greenhouse experiment. The results indicated that application of biofertilizers led to a significant (p<0.05) increase in the height of plant, root and stem lengths over the control group. The numbers of leaves per plant as well as chlorophyll content were highest in the treatments of biofertilizers (25 and 50%). Also, these treatments increased the total macro- and micro-nutrients of celery and lettuce plants. There was very remarkable enhancement in some recorded sandy soil properties after harvest i.e., pH, total organic matter, total nitrogen, phosphorus and potassium by the treatments of Bio-Mix with 25 and 50%. The present study concluded that 1/4 or 1/2 of the recommended dose of NPK fertilizers could be saved for celery and lettuce growth by using biofertilizers produced from cyanobacteria grown on olive milling or potatoes industry wastewaters as promising eco-friendly bio-organic fertilizers |