Activated sludge plant loads

Superrate. High BOD removal efficiencies (97%) at hydrauHc loadings of 10.8 m /(has) [1150 gal/(acred)] were obtained ia experimental plants with plastic media. In these plants, much of the microbial mass remains ia the recirculated effluent. This process is, ia effect, a modification of activated sludge. Organic loadings are ca 1.60 kg BOD/(m -s) [6.1 g BOD/(gal-s)]. 

In a specific activated sludge plant, the organic load is carried out at 0.8 kg BOD per kg MLSS-day 1 with an 80% BOD removal efficiency. Values for the above mathematical model are as follows. 

Reduction of the BOD is desirable, particularly for waste streams where the loading is 3-4 kg/tonne of pulp, or more. In concentration terms, BODs of 75-300 ppm (mg Oi/L) are common in kraft pulping effluents [39]. Biochemical waste treatment in activated sludge plants or artificially aerated waste lagoons, after adjustment of the water conditions to a pH in the 6.5-9 range, the temperature to 12-32°C, and addition of ammonium phosphate to provide nitrogen and phosphorus nutrients, accomplishes accelerated BOD reduction. Many of the bacteria, which are involved in this process have recently been isolated and identified [54]. Use of oxygen, rather than air, for... 

Does the unavailability of adequate valves, piping, etc. limit plant performance and reliability when other modes of operation of the existing plant can be utilized to improve performance (e.g., operate activated sludge plant in plug, step, or contact stabilization mode operate RBCs in step loading mode) ... 

Both these reactions occur in the aeration tank of the activated sludge plant and are favored in general by long retention time, low organic loading, large amounts of suspended solids, and high temperatures. The subsequent process, denitrification, removes nitrate from wastewater and occurs in the anaerobic condition (reaction (3))... 

Table 28 shows the comparative impact of operating with high or low loads in MWW treatment (activated sludge plants). 

The BOD removal efficiency of an activated sludge process treating 2000 m /day of condensate waste generated from a synthetic organic chemical plant is 94%. If the organic loading rate and BOD5 of the raw waste are 3.171 kg/m day... 

Biological treatment simulations consist of either continuous (CAS) or semicontinuous (SCAS) activated sludge tests that use either synthetic or natural sewage. The sewage or initial sewage inoculum usually is taken from a domestic wastewater treatment plant in order to reduce variability (industrial wastewater plants may contain very special chemical loadings) and to simulate treatment of consumer products. If treatability information in an industrial wastewater plant is desired, samples from the plant may be used. 

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