The present disclosure relates to a bacterium-alga coupled sewage treatment device based on energy recycling and a use method thereof. The device comprises a pretreatment device, a photobioreactor, an alga separation apparatus, a continuous flow bioreactor and a secondary sedimentation tank which are sequentially connected in order, the pretreatment device being connected to a municipal sewage inlet pipe, the photobioreactor being connected to a carbon dioxide gas charging device through a gas filling pipeline, one part of a sludge thickening tank being connected to the secondary sedimentation tank, the other part thereof being connected to remaining sludge of the pretreatment device, carbon dioxide generated from the sludge which flows through the thickening tank and is thermally-hydrolyzed and anaerobically-acidified being connected to the photobioreactor through a gas inlet pipeline, and the alga separation apparatus being further connected to a filter press. The present disclosure has the advantages of a rational structural design, reliable and stable operation, a low operation and maintenance cost and high automaticity and intelligence, and being suitable for the use and transformation requirements of a wide range of sewage treatment plants, etc.

A water treatment system includes a plurality of tanks; a plurality of blow systems connected to tanks respectively; a blower unit configured to supply air to tanks through the air blow systems; and a control device configured to: calculate a pressure loss in each of the air blow systems; and control supply of water to be treated to each of the tanks, according to the calculated pressure losses.

The present invention provides a method of treating wastewater in a wastewater system. The wastewater system comprises a treatment plant comprising a treatment space and a sewer system comprising a sewer space. The treatment plant further comprises a treatment inlet for supplying wastewater to the treatment system from the sewer system. The method comprises the step of: providing a treatment parameter being significant for purification of wastewater in the treatment plant, determining an actual spare plant capacity indicating an amount of wastewater which can be supplied to the treatment space, and determining an actual spare wastewater storage volume indicating an amount of wastewater which can be retained in the sewer space. The amount of wastewater supplied through the treatment inlet to the treatment plant is varied based on the treatment parameter, the actual spare plant capacity, and the actual spare wastewater storage volume.

A data-knowledge driven multi-objective optimal control method for municipal wastewater treatment process belongs to the field of wastewater treatment. To balance the energy consumption and effluent quality, a data driven multi-objective optimization model, including energy consumption model and effluent quality model are established to obtain the nonlinear relationship along energy consumption, effluent quality and manipulated variables. Meanwhile, a multi-objective particle swarm optimization algorithm, based on evolutionary knowledge, is proposed to optimize the set-points of nitrate nitrogen and dissolved oxygen. Moreover, the proportional integral differential (PID) controller is designed to track the set-points. Then the effluent quality can be improved and the energy consumption can be reduced.

An advanced nitrogen removal method using partial nitrification-denitrification coupled two-stage autotrophic denitrification. Sewage is introduced into a first pool for partial nitrification-denitrification treatment, and then introduced into a first regulating reservoir. Dissolved oxygen content in the first pool is kept at 0.4-0.6 mg/L. Water is discharged when a molar ratio of nitrite nitrogen to ammonia nitrogen in the first regulating reservoir is 1.0-1.3:1. Effluent in the regulating reservoir is introduced into a second pool for anaerobic ammonia oxidation treatment, and then introduced into a second regulating reservoir. In the second pool, pH is 7.0-7.4, a temperature is 22-28° C. Effluent in the second regulating reservoir and sulfides are introduced into a third pool for denitrification treatment. Water is discharged. In the third pool, pH is 7.5-8.0, a temperature is 28-32° C., a mass ratio of sulfur to nitrogen is 1.9-2.0:1.

In a cooperative optimal control system, firstly, two-level models are established to capture the dynamic features of different time-scale performance indices. Secondly, a data-driven assisted model based cooperative optimization algorithm is developed to optimize the two-level models, so that the optimal set-points of dissolved oxygen and nitrate nitrogen can be acquired. Thirdly, a predictive control strategy is designed to trace the obtained optimal set-points of dissolved oxygen and nitrate nitrogen. This proposed cooperative optimal control system can effectively deal with the difficulties of formulating the dynamic features and acquiring the optimal set-points.

A process for controlling the aeration rate during the aerobic phase of a wastewater treatment process is disclosed, which comprises: (a) measuring at moment t.sub.1 the ammonium concentration [NH.sub.4.sup.+].sub.1 and nitrogen oxide concentration [NO.sub.x].sub.1 in a mixture of wastewater and microbial sludge; (b) determining a nitrogen oxide target concentration [NO.sub.x].sup.F.sub.1 at the end of the aerobic phase based on at least the current ammonium concentration [NH.sub.4.sup.+].sub.1 and the current NO.sub.x concentration [NO.sub.x].sub.1; (c) determining a setpoint [NO.sub.x].sup.SP.sub.1 based on interpolation between [NO.sub.x].sub.1 and [NO.sub.x].sup.F.sub.1; (d) adjusting the aeration rate to minimise error between [NO.sub.x].sub.1 and [NO.sub.x].sup.SP.sub.1; and (e) repeating steps (a) to (d) at further moments t.sub.1. The invention further concerns a process for the treatment of wastewater, using the process.

The present invention belongs to the technical field of sewage denitrification. Disclosed are a sewage treatment system and method of continuous flow step-feed short-cut denitrification-anaerobic ammonia oxidation coupled with denitrification. The system comprises a primary sedimentation tank, a bioreactor and a secondary sedimentation tank, which are connected in sequence, wherein the bioreactor comprises a pre-starvation zone, a first hypoxic zone, a first aerobic zone, a second hypoxic zone and a second aerobic zone: an agitator is arranged in each of the pre-starvation zone, the first hypoxic zone and the second hypoxic zone; an aeration device is arranged in both the first aerobic zone and the second aerobic zone; a polyurethane sponge filler is arranged in both the first hypoxic zone and the second hypoxic zone; and a nitrification liquid reflux pump is arranged between the first aerobic zone and the pre-starvation zone. By rationally utilizing a carbon source of raw sewage, the present invention develops a sewage denitrification system and a process control method which have the advantages of an efficient denitrification effect, a simple procedure flow, being convenient in terms of operation and maintenance, and being automated and intelligent.

An efficient and low-cost process for gravity thickening and fermentation of waste activated sludge withdrawn from the surface of an activated sludge aeration basin for use with treatment systems designed for “enhanced biological phosphorus removal” (EBPR). One or more reactor tanks are used for the process with the steps of: A fill cycle, in which the waste mixed liquor flows into the tank, followed by a settle cycle, in which the mixed liquor is allowed to settle for a period of time, followed by a decant cycle, in which the clear liquid is withdrawn. The withdrawal of a volume of the settling mixed liquor for discharge is then followed by a ferment period for the remaining settled mixed liquor solids and a transfer of the fermented mixed liquor solids back to the activated sludge liquid stream process.

Methods are described for monitoring biofouling in a closed water system. For example, a method includes adding nitrate to water circulating in the closed water system, and detecting whether nitrite is present in the water after adding the nitrate. Another method includes introducing chlorite into water circulating in the closed water system, the detecting the amount of chlorite present in the water; and at least one of (i) comparing the detected amount of chlorite to an expected amount of chlorite; and (ii) observing whether the amount of chlorite in the water decreases over time.