scholarly journals Programmable logic controller-based automatic control for municipal wastewater treatment plant optimization

2021 ◽  
Author(s):  
Shunli Ning ◽  
Siyuan Hong
Keyword(s):  
Wastewater Treatment ◽  
Dissolved Oxygen ◽  
Oxygen Content ◽  
Wastewater Treatment Plant ◽  
Control Algorithm ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Programmable Logic Controller ◽  
Aeration Tank ◽  
Programmable Logic

Abstract The treatment of industrial wastewater can effectively protect the water environment and maintain sustainable development. This paper introduces an incremental proportion and integration (IPI) control algorithm-based programmable logic controller (PLC) used to adjust the aeration tank's dissolved oxygen content automatically in the wastewater treatment process. The control algorithm was improved by a back-propagation neural network (BP-NN). An instance analysis was carried out on a wastewater treatment plant in Zhejiang Province, China. This showed that the BP-NN improved control algorithm made the aeration tank's dissolved oxygen content more stable at the set value than it was with manual adjustment and the conventional algorithm. The total nitrogen content in wastewater treated in the aeration tank under the control of the improved IPI algorithm was minimized and fluctuated least. The aeration tank blower's power consumption was also at its lowest under the control of the improved IPI algorithm.

Treatment of Leather and Fur Wastewater by a Rotating Biological Contactor

1990 ◽  
Vol 22 (1-2) ◽  
pp. 119-126 ◽  
Author(s):  
Yang Zao-yan ◽  
Fan Zhen-san
Keyword(s):  
Wastewater Treatment ◽  
Liquid Film ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Great Influence ◽  
Treatment Plant ◽  
Aeration Tank ◽  
Municipal Wastewater Treatment ◽  
Rotating Biological Contactor ◽  
Volumetric Loading

The operation of a leather and fur wastewater treatment plant has been stable for 8 years. The volumetric loading was 85 to 110 l/m2.d, and the BOD loading and COD loading of the influent to the rotating biological contactor (RBC) were 15 to 20 g/m2.d and 50 to 65 g/m2.d respectively. Analyses have shown that the BOD5, COD, suspended solids (SS), S2−, and Cr3+ removals were 87.8, 77.4, 84.8, 93.6, and 81.0%, respectively. Several factors were considered in the design and performance of this leather and fur wastewater treatment plant. The pretreatment stage has a great influence on the operation of the RBC. The performance of the pre-aeration tank and primary clarifier regarding both BOD and COD removal approached 50%, therefore the organic loading of the RBC was reduced. However, shock flows of limewash waste from the workshop decreased the efficiency of the RBC. The high pH in the liquid film on the discs caused CaCO3 to precipitate and settle as scale on the surfaces of the discs. As the pH increased, NH3 stripping in the liquid film increased, and care had to be taken regarding proper room ventilation when the wastewater pH was high. Due to the high concentrations of organic matter and poorly biodegradable matter in the leather and fur wastewater, the rotational speed of the RBC must be increased compared with municipal wastewater treatment to ensure adequate aeration and to prevent blockages. In practice, the RBC linear velocities were between 25 to 30 m/min.

Modeling and Simulation of Dissolved Oxygen Concentrations in a Full-Scale Textile Dyeing Wastewater Treatment Plant

2010 ◽  
Vol 8 (1) ◽  
Author(s):  
Jingjie Yu ◽  
Guowei Gu ◽  
Shaopo Wang ◽  
Zhifeng Zhang ◽  
Liping Sun
Keyword(s):  
Wastewater Treatment ◽  
Dissolved Oxygen ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Full Scale ◽  
Aeration Tank ◽  
Dyeing Wastewater ◽  
Textile Dyeing ◽  
Textile Dyeing Wastewater ◽  
Oxygen Concentrations

A Modified Activated Sludge Model No.1 (M-ASM1), including six COD components (SI, SS, XI, XS, XH and SO) and three biochemical processes (aerobic growth of heterotrophs, aerobic decay of heterotrophs and hydrolysis of entrapped organics) is used to simulate the anaerobic hydrolysis-aeration- sedimentation treatment series in a full-scale textile dyeing wastewater treatment plant with an influent flowrate of 200,000 m3/d. M-ASM1 has the following characteristics: (1) the effect of temperature variation on biochemical reactions is included; (2) adding a parameter: ?. Using this parameter, the anaerobic hydrolysis tank and the aerobic initial compartments in which the dissolved oxygen concentrations are equal to "0 mg/L" can be differentiated; (3) the oxygen transfer coefficient KLa is excluded. Namely, as long as inputting the aeration flowrate, the pressure in the aeration pipe and other running data on air supply into this model, M-ASM1 can simulate the oxygen concentrations of each compartment in a plug-flow aeration tank.

scholarly journals Assessment of Microplastics in a Municipal Wastewater Treatment Plant with Tertiary Treatment: Removal Efficiencies and Loading per Day into the Environment

Water ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1339
Author(s):  
Javier Bayo ◽  
Sonia Olmos ◽  
Joaquín López-Castellanos
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Removal Rate ◽  
Treatment Plant ◽  
Source Control ◽  
Municipal Wastewater Treatment ◽  
Tertiary Treatment ◽  
Stable Performance ◽  
Wastewater Samples

This study investigates the removal of microplastics from wastewater in an urban wastewater treatment plant located in Southeast Spain, including an oxidation ditch, rapid sand filtration, and ultraviolet disinfection. A total of 146.73 L of wastewater samples from influent and effluent were processed, following a density separation methodology, visual classification under a stereomicroscope, and FTIR analysis for polymer identification. Microplastics proved to be 72.41% of total microparticles collected, with a global removal rate of 64.26% after the tertiary treatment and within the average retention for European WWTPs. Three different shapes were identified: i.e., microfiber (79.65%), film (11.26%), and fragment (9.09%), without the identification of microbeads despite the proximity to a plastic compounding factory. Fibers were less efficiently removed (56.16%) than particulate microplastics (90.03%), suggesting that tertiary treatments clearly discriminate between forms, and reporting a daily emission of 1.6 × 107 microplastics to the environment. Year variability in microplastic burden was cushioned at the effluent, reporting a stable performance of the sewage plant. Eight different polymer families were identified, LDPE film being the most abundant form, with 10 different colors and sizes mainly between 1–2 mm. Future efforts should be dedicated to source control, plastic waste management, improvement of legislation, and specific microplastic-targeted treatment units, especially for microfiber removal.

scholarly journals Energy Valorisation of Wastewater Treatment Plant Sludge through Thermal Gasification: An Economic Perspective

Proceedings ◽  
2021 ◽  
Vol 52 (1) ◽  
pp. 3
Author(s):  
Luis F. Carmo-Calado ◽  
Roberta Mota-Panizio ◽  
Gonçalo Lourinho ◽  
Octávio Alves ◽  
I. Gato ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Wastewater Treatment Plant ◽  
Municipal Wastewater ◽  
Treatment Plant ◽  
Electricity Production ◽  
Baseline Scenario ◽  
Municipal Wastewater Treatment ◽  
Plant Processing ◽  
Sludge Drying ◽  
Calorific Power

The technical-economic analysis was carried out for the production of sludge-derived fuel from a municipal wastewater treatment plant (WWTP). The baseline for the analysis consists of a sludge drying plant, processing 6 m3 of sludge per day and producing a total of about 1 m3 of combustible material with 8% of moisture and a higher calorific power of 18.702 MJ/kg. The transformation of biofuel into energy translates into an electricity production of about 108 kW per 100 kg of sludge. The project in the baseline scenario demonstrated feasibility with a payback time of about six years.

Sign in / Sign up

Export Citation Format

Share Document