الفهرس 
Chapter OneOnly 14 pages are availabe for public view
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Abstract
The objectives of the present study were to evaluate the efficiency of bacterial additives (BiOWiSH) for domestic wastewater treatment biologically in designed septic tanks system. Also, to use the optimum dose of BiOWiSH in septic tank to reduce BOD, COD, TSS, Ammonia, total nitrogen total phosphorus, Oil and grases and coliform group.
Results showed that, the bacterial mixture of BiOWiSH was identified using Biolog GNII. The identified bacterial was Pediococcus acidilactici, Pediococcus pentosaceus, Lactobacillus plantarum and Bacillus subtilis.
To achieve the first aim, one raw domestic wastewater sample and 5 samples after adding different doses of BiOWiSH. The experiment was repeated 3 times. Also, 5 samples (1 raw and 4 after different biofilter steps). Multiple tube fermentation technique was used to determine the total and fecal coliform. Also, the optimum dose was used in a multi stages biofilters to enhance the effluent treated wastewater quality to reuse it.
It can be found that average values of the characteristics of the domestic wastewater showed that the concentrations of COD, DO, BOD5, TS, TDS, TSS, Ammonia, Nitrate, Nitrite, Total Phosphorus, TKN, Oil and grases were, 1431, 0.22, 274.8, 398, 558, 160, 49.28, 13.78, 0.03, 28.71, 10.8, and 50 mg/L, respectively. While the count of Total Coliform and Faecal Coliform were 350 x109 and 140 x109 MPN-index/100ml respectively.
It can be found that PH, H2S, COD, DO, BOD5, TS, TDS, TSS, ammonia, Nitrate, Nitrite, TP, TKN and oil &grease for final effluent with 100 mg/L (lowest dose) of BiOWiSH after Six hours as optimum and sufficient contact time , were 7.38, 7.4, 244, 0.25, 66.4, 455.66, 396, 42.66, 17.8, 11.98, 0.021, 22.458, 8.6 and 10 mg/L, respectively. While at 300 mg/L (highest dose) results after Six hours were 7.37, 7.3, 285, 0.28, 82.2, 415.33, 344, 28.33, 5.8, 11.0, ND, 14.63, 6.43 and 7.2 mg/L, respectively.
In case of bacteriological analysis, results found that TC and FC at lowest dose after Six hours were 160×l08 and 22× 108 MPN-Index/100 ml respectively. While at highest dose after Six hours, results of TC and FC were 150×l07 and 15 × 107 MPN-Index/100 ml respectively. This may be due to the increase bacterial additives dose which can be able to reduce the organic load and inhibit the bacterial populations.
While Results of average level of physic-chemical parameters (PH, H2S, COD, DO, BOD5, TS, TDS, TSS, ammonia, Nitrate, Nitrite, TP, TKN and oil &grease) in effluent treated with 250 mg/L after Six hours were 7.39, 5.7, 196, 0.38, 71.3, 370.2, 360, 24.5, 4.96, 10.2, ND, 12.90, 4.2 and 6 mg/L, respectively. While, the number of TC and FC in effluent were 140×l07 and 11×l07 MPN-index/100 respectively. Also, results noticed that, this dose considered as an optimum and effective dose of biological additives for domestic wastewater treatment in septic tank system.
Generally, results illustrated that, 250 mg/L of BiOWiSH was considered as the optimum dose for decreasing Physico-chemical (PH, H2S, COD, DO, BOD5, TS, TDS, TSS, ammonia, Nitrate, Nitrite, TP, TKN and oil &grease). Also, results indicated that, this dose able to decrease the total and fecal coliform enumeration. With contact time period of 6 hours as optimum and sufficient contact time.
Results showed that, the suspension of BiOWiSH (250 mg/L) material had antimicrobial effect against tested microorganisms. Regarding toxicity assay, the results for the suspension of BiOWiSH (250 mg/L) material found that, this material was nontoxic against cell culture and non-toxic using Microtox Model 500.
To accomplish the objectives of this study a multi stages biofilters (as pilot scale plant) simulating a septic tank system was designed and manufactured. It was used with optimum does of bacterial additives (BiOWiSH) to enhance the effluent treated WW quality to reuse it.
After determining the optimum dose of the BiOWiSH (Bacterial additive), a multi stages biofilters was used to enhance the effluent treated wastewater quality in order to reuse it. A continuous pilot scale system was designed. The domestic wastewater mixed with the optimum dose of the BiOWiSH (bacterial additives) which obtained from experiments in a model of septic tank of 2 L capacity. The contact time was two hours, and the flow rate was 0.5 L/min. The effluent treated wastewater was filtered through multi stages down flow biofilters. The multi stages biofilters consists of three tanks of 25 L capacity. filled with 20 cm gravel and sand acting as a filter media. The tank A act as precipitation tank without any filter media, The size of gravels in tank B 5-6 mm, while in tank C was 1-2 mm. The experiment was repeated three times to calculate the average.
Finally the average recovery rate of purification in the three applications show increase in PH, and DO with percentage of 7.3%, and 23, 18.3% respectively) and decrease in H2S, COD, BOD5, TS , TDS, TSS, ammonia, Nitrate, Nitrite, TP, TKN , oil &grease, T.coliforms , faecal coliforms and conductivity with removal percentage of (83.4%, 94%, 80.9%, 37.1%,50.9%, 93.2%, 100%, 57.1 ,ND ,76.4%, 76%, 99.9%, 99.9%, 100 % and 50.9% respectively.
This may be due to optimum dose of bacterial additives 250mg/L which can be able to reduce the organic load and inhibit the bacterial populations.
With this technology BiOWiSH, high WW treatment efficiency can be achieved in this system.
Average results showed that PH, H2S, COD, DO, BOD5, TS, TDS, TSS, ammonia, Nitrate, Nitrite, TP, TKN , oil &grease T.coliforms , faecal coliforms and conductivity after sedimentation were 7.3, 4.12, 202, 0.53, 78, 311, 546, 16.33, ND, 7.44, ND, 11.2, 4.1, 6.8, 0.00011, 0.08 and 228 mg/L, respectively. And after using gravel filter were 7.41, 3.2, 174, 3.41, 59, 272.4, 301, 14.56, ND, 5.82, ND, 9, 2.82, 1.88, 0.008, 0.00006 and 150.5 mg/L, respectively, finally after sand filter were 7.52,1.4, 82, 5.89, 33, 213, 284, 9.89, ND, 4.96 , ND, 7.1, 1.86, 0, 0.0004, 0.000004 and 142 mg/L, respectively.
Thus, the bacterial additives (2.5 ppm BiOWiSH) improve the performance of septic tank in WW treatment for irrigation reuse.