الفهرس 
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Abstract
The current study aimed to isolate and identify some bacteria and actinomycetes strains from sewage sludge (SS) at Beni-Suif wastewater treatment plant, Egypt which can be used in the treatment. Eight strains were isolated from SS under aerobic conditions. Among the colonies appeared on the plates, 4 bacterial isolates, and 4 actinomycete. The ability of the eight strains of bacteria and actinomycetes in the biodegradation and removal of the organic pollutants of sewage sludge (SS) through using the dried sludge (DS) as a substrate media and the removal efficiency of COD, BOD, TSS and VSS parameters were tested. Different concentrations of DS 1, 2, 3 and 4gm in different conditions of aerobic and anaerobic treatment were applied. Three grams of concentrated DS in anaerobic conditions were recorded high removal efficiency with isolates No (A&F). Also mixture of the two potent actinomycetes (A&F) recorded highly removal efficiency under normal anaerobic condition (nonsterilized sludge) after 5 days incubation at 32 o C.
The bacterial isolates were identified by their morphological and biochemical characteristics. The bacterial population was dominated by Dermacoccus nishinomiyaensis (95% probability), Kocuria rosea (95% probability), Streptococcus parasanguinis (95% probability), Kocuria varians (97% probability). On the other hand, the two potent actinomycetes strains which give the best results among all isolated strains in the treatment were identified by 16s rDNA and phylogenetic analysis and they were defined as Nocardiopsis lucentensis and Saccharomonospora azurea, Saccharomonospora azurea proposed as a new species.
The experimental data revealed that mixed culture of N lucentensis and S azurea (the two potent isolates) gave high significant removal efficiency of organic wastes; consequentially this mixture was chosen to treat dried SS of Beni-suif wastewater treatment plant by applying two types of biological treatment aerobic and anaerobic treatment at 35±2oC comparing to the controls. Control represented untreated dried SS.
The data revealed that aerobic treatment give significant reduction by 42.5, 87.4, 31.3 and 52.7% for COD, BOD, VSS and TPO4 respectively at the end of treatment compared to control which recorded 37.4, 77.4, 23.9 and 43.7% for COD, BOD, VSS and TPO4 respectively at the end of treatment. Also aerobic treatment had a high ability to purify SS from pathogenic bacteria as all measured parameter were highly significantly decreased and recording 100% removal for total coliform after 40 day of the incubation. The data also indicated that the removal efficiency of salmonella reached to 100% removal after 50 day. On the other hand the removal efficiency for Fecal Coliform reached to 100% removal after 20 day of incubation only.
Aerobic treatment recorded removal efficiency of heavy metals by 36.2, 37.2, 33.1, 27.9 and 30.6% for Fe, Mn, Cu, Cr and Pb respectively at the end of treatment compared to control which recorded 21.3%, 22.9%, 29.1%,19.8% and 18% for Fe, Mn, Cu, Cr and Pb respectively at the end of treatment. On the other hand the removal efficiency of some mineral salts under aerobic recorded 39.1, 10.7, 31.5and 28.8% removal for Na, Ca, K and Mg respectively at the end of the biodegradation compared to control which recorded 29.8, 8.3, 17 and 18% removal.
The result revealed that anaerobic treatment give highly significant removal efficiency by 78.8, 92.5,63.8 and 57.4% for COD, BOD,VSS and TPO4 respectively at the end of treatment compared to control which recorded 63.44, 81.9, 57 and 48% removal. The completely disappearance of all pathogenic bacteria from SS under anaerobic treatment and 100% removal efficiency after 10 days incubation period were recorded. The result also indicated that anaerobic treatment recorded a significant removal efficiency of heavy metals by 46.4, 36.6, 44.9, 42.2 and 61% for Fe, Mn, Cu, Cr and Pb respectively at the end of treatment compared to control which recorded 32.5, 29.3, 37.1, 24.5 and 28.2 % reduction for Fe, Mn, Cu, Cr and Pb respectively. On the other hand the removal efficiency of some mineral salts under anaerobic treatment recorded 55.7, 42.2, 56.3 and 49% reduction for Na, Ca, K and Mg respectively at the end of treatment compared to control which recorded 31.9, 34, 30.3 and 26% removal.
By comparing two types of biological treatments we can observe that anaerobic treatment significantly increased the removal efficiency by 85%, 104% and 140% for COD, VSS and pathogenic Salmonella respectively. Also anaerobic treatment reduced the amount of heavy metals and mineral salts compared to aerobic treatment especially for Ca, Pb and Mn by 318%, 99% and71% respectively.
Using the different concentrations of treated SS as biofertilizer in sandy soil was studied. The effect of different concentrations of treated SS on growth parameters of Zea mays compared to control and compared with applying different concentrations of untreated SS resulted in a significant increase in growth of Zea mays in case of treated SS compared to control but concentrations more than 6% inhibit the growth of Zea mays. On the other hand all concentrations of untreated SS inhibit the growth.