scholarly journals Influent temperature effects on the activated sludge process at a municipal wastewater treatment plant

2019 ◽  
Vol 64 (1) ◽  
pp. 113-123
Author(s):  
Marius-Adrian Brehar ◽  
◽  
Várhelyi Melinda ◽  
Vasile-Mircea Cristea ◽  
Daniel Crîstiu ◽  
...  
2019 ◽  
Vol 11 (3) ◽  
pp. 622 ◽  
Author(s):  
Isabella Pecorini ◽  
Francesco Baldi ◽  
Renato Iannelli

Four inocula collected from different operating facilities were tested in their hydrogenic performances by means of two biochemical hydrogen potential test set-ups using sucrose and food waste as substrates, with the aim of evaluating the influence of inoculum media in batch fermentative assays. The selected inocula were: activated sludge collected from the aerobic unit of a municipal wastewater treatment plant, digested sludge from an anaerobic reactor treating organic waste and cattle manure, digested sludge from an anaerobic reactor treating agroindustrial residues, and digested sludge from an anaerobic reactor of a municipal wastewater treatment plant. Test results, in terms of specific hydrogen production, hydrogen conversion efficiency, and volatile solids removal efficiency, were significantly dependent on the type of inoculum. Statistical analysis showed different results, indicating that findings were due to the different inocula used in the tests. In particular, assays performed with activated sludge showed the highest performances for both substrates and both experimental set-ups.


2017 ◽  
Author(s):  
Alexandre Amaro ◽  
Henrik Hanson ◽  
Fabio Kaczala ◽  
Marcia Marques ◽  
William Hogland

Three ozone-based advanced oxidation treatments (O3; O3 with initial pH adjustment and; O3/UV with initial pH adjustment) were compared for the treatment of a recalcitrant wastewater generated during washing/cleaning of surfaces and equipment used in filling and gluing processes (urea-formaldehyde and phenol-formaldehyde resins) in a wood-floor industry in Sweden. The wastewater (initial COD 3,400-4,000 mg/L) was obtained at the outlet of a sedimentation tank, which receive an inflow with an average COD of 45,000 mg/L. The experiments were performed in a semi-batch microbubble column reactor connected to a UV reactor, where 2.5 L samples of wastewater were submitted to the maximum dose of 2 g of O3 per gram of initial COD. For the full-factorial design, the independent variables were O3 concentration (g O3/Nm3); recirculation flow (L/min); and initial pH (pHi). The evaluation of the treatment performance was based on COD and TOC reductions (in %), and the effluent obtained was used in respirometric assays with activated sludge obtained at a municipal wastewater treatment plant to assess biodegradability/inhibitory effects. The results showed that ozonation at the original low pH promoted a reduction of 65% and 31% of COD and TOC respectively, but made the effluent less biodegradable. The highest COD and TOC reductions were achieved when O3 /UV treatment with pHi = 9.3 were applied (93% e 56% reductions for COD and TOC respectively). The results with the respirometry tests suggest that application of O3 only at higher pH values promoted biodegradability enhancement of the effluent, making it treatable by microbiota obtained with activated sludge from a municipal wastewater treatment plant.


1998 ◽  
Vol 38 (3) ◽  
pp. 167-172
Author(s):  
Jin Duanyao ◽  
Wang Baozhen ◽  
Wang Lin

The Zhen'an Wastewater Treatment Plant in Foshan City, Guangdong Province, China is a newly built large municipal wastewater treatment plant in south China, situated in the southeast of the famous ancient Foshan City, has a treatment capacity of 100,000 m3/d, serves an area of 32 km2 and 220,000 P. E., occupies 7 ha area with a total investment of 220 million RMB (about 26.5 million U.S dollar), which was put into operation in December 1995. As it is difficult to design and operate the wastewater treatment plant because of the low organic concentration of its influent, the simplified A/O activated sludge process without primary treatment for simultaneous removal of phosphorus and ammonia nitrogen was employed to design the plant, by which, the wastewater is treated very well, with higher effluent quality than the traditional activated sludge process, while the capital and O/M costs are lower than the latter.


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