進入2005年后，公司根據曝氣設備落后于我國污水處理領域快速發展現狀，迅速轉型曝氣設備的創新研制，經過十多年的的研發與污水廠現場應用實踐，先后擁有以潛浮式曝氣機和潛浮式推流攪拌機為核心的污水處理系列裝備；先后取得中華人民共和國國家知識產權局和美利堅合眾國專利與商標局頒發的各四項發明專利證書（1.潛浮式曝氣機,專利號200610168196.0；2.由導氣筒直接進氣的潛浮式曝氣機，專利號200710165152.7；3.回轉潛浮式曝氣機，專利號200810089642.8；4.多向潛浮式曝氣機，專利號200910160936.X；5.Submersible Hollow Shaft Motor and Submersible Floating Aerator Comprising the Same，專利號7661658；6.Swing-Type Submersible Floating Aerator，專利號7661659；7.Multi-directional Submersible Floating Aerator，專利號7934705；8.Aeration Ship, 專利號8998179）。2010年至2015年間，在中國濟南與環保界學者專家共同探討產生了“中層曝氣”新概念，與經典之底層曝氣、表層曝氣兩大體系并列其中。底曝、中曝、表曝形成污水處理廠三種曝氣裝備并存階段。
Shandong Yida Environmental Technology & Engineering Co., Ltd. is a hi-tech company established in 1994. During the past three decades, the company has been dedicated in innovation, practice and continuous improvement in industrial and municipal sewage treatment, ecological restoration and nitrogen removal of surface water. The company has successfully completed a range of sewage treatment turnkey projects for many customers by implementing state-of-the-art technologies. We used highly efficient technologies in various industrial sewage projects to achieve the goal of low investment, low operating costs and high effluent quality. Since the after-sale service was excellent, the company has won great reputation from the customers and the environmental protection agencies. In August 1999, the company received the Certificate of Environmental Engineering Design issued by the State Environmental Protection Administration.
Since the progress of aeration equipments lagged far behind the quick development of sewage treatment market demand in China, the company shifted to the innovation of new aeration devices in 2005. After ten years of research and development, the company has successfully developed the submersible floating aerator and mixer as core equipments for wastewater treatment plants. We created “middle-layer aeration”, a new concept that starts a new epoch in conventional aeration industry. The company has successively obtained eight patent certificates issued by China National Intellectual Property Administration and United States Patent and Trademark Office (1. Submersible Floating Aerator, patent number 200610168196.0; 2. Submersible Floating Aerator With Direct Air Intake From the Air Tube, patent number 200710165152.7; 3. Swing-type Submersible Floating Aerator, patent number 200810089642.8; 4. Multi-directional Submersible Floating Aerator, patent number 200910160936.X; 5. Submersible Hollow Shaft Motor and Submersible Floating Aerator Comprising the Same, patent number 7661658; 6. Swing-type Submersible Floating Aerator, patent number 7661659; 7. Multi-directional Submersible Floating Aerator, patent number 7934705; 8. Aeration Ship, patent number 8998179). From the year 2010 to 2015, the concept of "middle layer aeration" was jointly developed by environmental scholars and experts in Jinan, China. The concept of middle-layer aeration co-exists with the other two major systems, namely, bottom aeration and surface aeration.
From the year 2016 to 2022, the company started the mashup phase by inserting its middle-layer aerators into the basins consisting of bottom and surface aeration systems. After implementing middle-layer aeration with no production suspension, the effluent quality rised and treatment cost declined dramatically. We have reached a consensus with the plant owners to adopt the "three aeration modes in one" approach for the retrofit of the WWTP. That is, if the retrofit process started, the original design would not be changed, the equipment would not be dismantled, the new additions would not be constructed, the carbon source would not be added to the municipal sewage, the production would not be suspended, and the basins would not be cleaned up. By installing several units of digital controlled submersible floating aerator and mixer, the basin could rapidly be changed into a dynamo with increased dissolved oxygen (DO). Simultaneous nitrification and denitrification (SND) would be swiftly created by accurate control of the aerators. The sinking sludge would be activated, and the oxygen supply of the bottom aeration system would be restored quickly. The combined effects of the swing device, push-flow and mixing lead to the following results. The nitrogen released in the activated sludge was cleaned up. The ammonia nitrogen and total nitrogen levels are reduced to meet grade 1A wastewater or grade IV surface water standard. After the insertion into oxidation ditches and A2O basins consisting of anaerobic selective tanks, not only can ammonia nitrogen and total nitrogen be efficiently removed, but also total phosphorus biological removal can be achieved. In addition, the cost per ton of water could be reduced by 30% -50%. The reduction of residual sludge could enter more than 30%. The retrofit could result in a significant decrease in treatment cost.
After the insertion upgrading by installation of the digital controlled submersible floating aerators and mixers, the following three points have been established.
(1) A new model of "three aeration modes in one basin" is the solution to the continuing overcapacity, lacking of operating repairs of equipment, and the decline of treatment capacity of WWTP.
(2) The dual-mode control solves the contradiction between low sludge activity (MLVS/MLSS) and high sludge concentration. The strong push flow and mixing energy effectively discharges inorganic deposited sludge, quickly improving the imbalance condition of activated sludge, and restoring stable effluent quality. The dual energy separate control solved the problem of excessive ammonia nitrogen in effluent caused by the increase of dissolved oxygen and the decrease of denitrification effect due to the increase of bottom aeration to residual sludge.
(3) By installing some units of middle layer aerators in the surface aeration system in the oxidation ditch, the tilt down of the submersible motor and propeller provide push-flow and mixing energy to roll up the deposited sludge and supply sufficient oxygen to the tank bottom. By using the swing bearing and the tank’s sidewall to separate off the mixing energy, two split-flows are created. The lower one rolls up the settled sludge at the tank bottom, the upper one rolls down the high DO liquor and organic foam and mixes them with the sludge. The DO level remains consistent at the bottom, middle and surface part of the basin. The routine maintenance can be performed without operational suspension. The effluent quality remains stable. The sludge bulking ceases to exist.