در هنگام جستجو کلمه در قسمت عنوان میتوانید کلمات مورد جستجو را با کاراکتر (-) جدا کنید.
کاربرد نوع شرط:
- جایگاه : پژوهشی
- مجله: Journal of Advances in Environmental Health Research
- نوع مقاله: Journal Article
- کلمات کلیدی: Dissolved oxygen,Biological wastewater treatment,Air Nanobubbles,Excess Sludge
- چکیده:
- چکیده انگلیسی: Low efficiency of conventional aeration techniques and the excessive production and disposal of sludge are great concerns in biological wastewater treatment systems. The present study aimed to evaluate the active sludge method using batch reactors under continuous operation to determine the efficiency of aeration and sludge production through microbubble and nanobubble aeration. The results indicated that compared to microbubble aeration, nanobubble aeration increased the concentration of dissolved oxygen in the mixed liqueur of the reactor (from 2 to 4.5 mg/l), while reducing the production of excess sludge from 100 to 40 ml/g (SRT: 15-40 d). With the same SRT duration, these values were within the range of 160-70 ml/g using fine-bubble aeration. According to the results, nanobubble aeration could increase the efficiency of aeration, thereby increasing the capacity of the treatment plant and reducing the costs of biological wastewater treatment.
- انتشار مقاله: 21-03-1397
- نویسندگان: Mehrdad Ahmadi,Gholamreza Nabi Bidhendi,Ali Torabian,Nasser Mehrdadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Journal of Advances in Environmental Health Research
- نوع مقاله: Journal Article
- کلمات کلیدی: Dissolved oxygen,Biological wastewater treatment,Air Nanobubbles,Excess Sludge
- چکیده:
- چکیده انگلیسی: Low efficiency of conventional aeration techniques and the excessive production and disposal of sludge are great concerns in biological wastewater treatment systems. The present study aimed to evaluate the active sludge method using batch reactors under continuous operation to determine the efficiency of aeration and sludge production through microbubble and nanobubble aeration. The results indicated that compared to microbubble aeration, nanobubble aeration increased the concentration of dissolved oxygen in the mixed liqueur of the reactor (from 2 to 4.5 mg/l), while reducing the production of excess sludge from 100 to 40 ml/g (SRT: 15-40 d). With the same SRT duration, these values were within the range of 160-70 ml/g using fine-bubble aeration. According to the results, nanobubble aeration could increase the efficiency of aeration, thereby increasing the capacity of the treatment plant and reducing the costs of biological wastewater treatment.
- انتشار مقاله: 21-03-1397
- نویسندگان: Mehrdad Ahmadi,Gholamreza Nabi Bidhendi,Ali Torabian,Nasser Mehrdadi
- مشاهده
- جایگاه : پژوهشی
- مجله: Iranian Journal of Chemistry and Chemical Engineering
- نوع مقاله: Journal Article
- کلمات کلیدی: Ozone,reactor,sludge reduction,Oxidation of sludge,Yield coefficient
- چکیده:
- چکیده انگلیسی: The excessive biological sludge production is one of the disadvantages of aerobic process such as SBR. So the problem of excess sludge production along with its treatment , and disposal in aerobic processes in municipal and industrial waste water can be seen in many parts of the world even in our country . to solve the problem of excess sludge production , reducing in by oxidizing some of the sludge by Ozone is a suitable idea , thus reducing the biomass coefficient as well as the sewage sludge disposal. In this study, Two SBR reactors with of 20 liter being controlled by on-line system are used. After providing the steady state in the reactors, along the 8 month research sampling and testing parameters such as COD, MLSS, MLVSS, DO, SOUR, SVI, residual ozone and Yield coefficient were done. The results showed that during the solid retention time of 10 days the kinetic coefficient of Y and Kd was 0.58 (mg Biomass / mg COD) and 0.058 (1/day) respectively. At the next stage of research, different concentrations of ozone in one liter of the returned sludge to reactor were used to reduced the excess biological sludge production. The results showed that the 20 mg ozone per gram of MLSS in one liter of the returned sludge to reactor is able to reduce Yield coefficient from 0.58 to 0. 28 (mg Biomass/mg COD),In other words, the biological excess sludge by 52 % .but the soluble COD increased slightly in the effluent and the removal percentage decreased from 92 in blank reactor to 64 in test reactor. While the amount of SVI and SOUR in this consumed ozone concentration reduced 9 mgO2/h.gVSS and 20 ml/g respectively. No sludge was seen in the 25 mg ozone concentration per gram of MLSS in one liter of the returned sludge to reactor.
- انتشار مقاله: 01-05-1387
- نویسندگان: Afshin Takdastan,Naser Mehrdadi,Ali Akbar Azimi,Ali Torabian,Gholamreza Nabi Bidhendi
- مشاهده