Enhancement of nitrogen and phosphorus removal, sludge reduction and microbial community structure in an anaerobic/anoxic/oxic process coupled with composite ferrate solution disintegration

Nitrogen Removal and Sludge Reduction in Anoxic-Aerobic Sequencing Batch Reactor with Alkaline-H2O2 Disintegration

“…The release of organic and nutrients by the sludge lysis process increases the pollution load of the reactor. While some studies stated that the load increase due to sludge lysis decreased the reactor performance [31,32], some studies stated that it did not affect the reactor performance [18,33,34]. In this study, no change was observed in the COD and nitrogen removal efficiency as a result of the return of the sludge lysis effluent to the reactor.…”

Disintegrated Waste-Activated Sludge (NO2/FNA Method) as a Source of Carbon for Denitrification in the Mainstream of a WWTP

“…For the supernatants after WAS disintegration, the SCOD/TN ratios were 9 (R7), 11 (R4, R5), and 18 (R6, R8). These values were lower than those reported as being favorable for carbon sources to enhance nitrogen removal (25-30 SCOD/TN) [2], but substantially higher than the COD demand for denitrification, which is 2.86 gCOD/gN. The addition of nitrogen to activated sludge leads to the The SCOD/TN ratio is an important factor when considering external carbon sources for denitrification in the mainstream of a WWTP.…”

“…Therefore, its efficient removal from wastewater is required [1]. Activated sludge processes (with enhanced nutrient removal) are widely used in wastewater treatment plants (WWTPs) due to their relatively simple operation, low cost, and high efficiency [2]. The biological removal of nitrogen is conventionally carried out via the autotrophic conversion of ammonia to nitrite and nitrate under aerobic conditions (nitrification), which is then followed by heterotrophic reduction to dinitrogen gas under anoxic conditions (denitrification) [3].…”

“…Wu et al (2018) indicated a strong effect of FNA on cell membrane disruption and a limited role in EPS disintegration [1]. Wang et al (2018) concluded that FNA induces the permeabilization of bacteria and may lead to cell membrane lysis [2]. Despite the lack of a complete understanding of the mechanism, many studies have proven the effectiveness of NO 2 /FNA as a WAS disintegration agent in terms of soluble chemical oxygen demand (SCOD) release, and consequently for increased methane production [12][13][14].…”

Removals of Organic and Nitrogen in Biogas Effluent by Aao System

“…The treatment efficiency of NH 4 + gradually increases from the anaerobic to the aerobic compartment (Figure 4). Zhang et al [10] evaluates the enhancement of nitrogen and phosphorus removal and sludge reduction in an AAO-CFSSDR (Anaerobic/Anoxic/Oxic combined with CFS-Sludge disintegration reactor) process suggested that the removal efficiencies of TN, NH 4 + -N and TP increased from 71.15, 79.23 and 85.52% to 85.05, 87.70 and 90.06%, respectively; and the sludge was reduced by 34.79%. This research shows an application of cheap plastic materials as a medium for microorganism so that the removal efficiency of nitrogen ammonium could enhance up to 70%.…”