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The practical guide on what to do right when biological influences cause a sequencing batch reactor to go wrong This richly illustrated, straightforward guide carries forth the legacy established by previous editions in the Wiley Wastewater Microbiology series by focusing attention on the mixed gathering of organisms cohabitating within a sequencing batching reactor (SBR), and the key roles their biology plays in this wastewater processing tank's function. With a clear, user-friendly presentation of complex subject matter, Troubleshooting the Sequence Batch Reactor first teaches plant operators how to differentiate the positive and expected organismal dynamics present in optimal SBR performance from the negative and damaging ones that create unhealthy sludge, and a stoppage in SBR operations. Next, Troubleshooting the Sequence Batch Reactor delivers all the tools necessary to get an SBR back on track and running safely. In this book you'll get: * Short-course situations tested by the author for the past fifteen years * Accessible material aimed at operators instead of design and consulting engineers * Essential information for understanding biological conditions such as aerobic, anoxic, and anaerobic/fermentative at the treatment process * Examination of the properties of protozoa (single-celled) and metazoa (multi-celled) organisms, and their significance in wastewater treatment Devoid of overwhelming scientific jargon, chemical equations, and kinetics, this book simplifies details to provide quick instruction for plant operators on how to make more informed day-to-day process control decisions, how to troubleshoot confidently when SBR conditions become compromised, and how to act decisively when the problem is ultimately identified.

The effects of biological factors including dissolved oxygen (DO), pH, carbon/nitrogen (C/N) and hydraulic retention times (HRT) on the performance of simultaneous nitrification and denitrification (SND) in a moving bed sequencing batch reactor (MBSBR) were investigated. A low DO was found to be advantageous to the SND in that nitrification was not inhibited, while pH and C/N ratio were shown to have positive effects on SND, and HRT needed to be controlled in a suitable range. A desirable SND efficiency was obtained at a DO of 2.5 mg L −1 , pH of approximately 8.0, C/N ratio of 10 and HRT of 10 h in the MBSBR. High-throughput sequencing analysis showed that different operating conditions impacted microbial communities, resulting in different nitrogen removal mechanisms. Autotrophic and heterotrophic nitrification together contributed to the good nitrification performance, while denitrification was conducted by combined anoxic and aerobic processes. Furthermore, the results of principal component analyses (PCA) and the abundance of the predominant nitrification and denitrification genera both showed that DO and HRT might be regarded as the dominant variable factors influencing community structure analysis during SND, while the linear discriminant analysis (LDA) effect size (LEfSe) algorithm showed differences in abundance among the biofilm microbial communities with different DO. Overall, the results of this study improve our understanding of the bacterial community structure with different operating conditions in MBSBRs.

Abstract In this study, sequencing batch reactor (SBR) using anaerobic/aerobic/anoxic process was coupled to a solar photocatalytic reactor (SPCR) for greywater treatment. The greywater effluent from SBR (operated at the optimal condition: 6.8 h hydraulic retention time (HRT), 0.7 Volumetric exchange ratio (VER) and 7.94 d solids retention time (SRT) with optimal corn cob adsorbent dosage (0.5 g/L)) was fed to the SPCR (operated at optimal conditions: pH – 3, H2O2 dosage – 1 g/L, catalyst dosage – 5 g/L). Chemical oxygen demand (COD) removal of 92.8±0.5% and ∼100% were achieved in SBR and SBR-SPCR, respectively. Similarly, total organic carbon (TOC) removal of 91±0.9% and ∼100% were observed in SBR and SBR-SPCR, respectively. After SBR treatment, average total nitrogen (TN) removal of 84% was found and this TN removal increased to 93% after combined SBR-SPCR treatment. The maximum PO43−_P reduction of 80±1.5% % was achieved with SBR-adsorption system. In addition, a maximum of 87±0.9% of net PO43−_P removal was reached after SBR-SPCR treatment. 58.9±2.3% BP (benzophenone-3) removal was obtained in the SBR while the integration of SBR and SPCR treatment was resulted in 100% BP removal. An effective anionic surfactant (AS) removal rate (80.1±2.2%) was observed in the SBR phase, which further improved to 94.9±1% at the end of 4 h SPCR treatment.

The fixed-film sequencing batch reactor, or F-SBR, was developed to treat high organic compound levels and toxic cyanide concentrations in cassava wastewater. The performance of the F-SBR was compared with that of a conventional sequencing batch reactor, or SBR, that was operated with organic compound contents of 16,266.67–26,666 mg COD/L and 132.92–252.66 mg CN − /L. The cyanide and chemical oxygen demand removal efficiencies of the conventional SBR system were 42.61% and 36.83%, respectively, while those of the F-SBR were 77.95% and 74.43%, respectively; the cyanide removal efficiency reached 95.45% when the hydraulic retention time was increased to 5 days, and the F-SBR was very effective for the complete removal of cyanide when the hydraulic retention time was increased to 10 days. This effectiveness was similar to the effectiveness of chemical oxygen demand removal, which reached 40–78% efficiency with the F-SBR system. These results showed that the immobilization of cyanide-degrading bacteria such as Agrobacterium tumefaciens SUTS 1 and Pseudomonas monteilii SUTS 2 carried out with a polypropylene ring in a fixed-film aerobic system enhanced the performance of the reactor and can be successfully applied for cyanide and chemical oxygen demand removal from industrial wastewater with high cyanide and chemical oxygen demand concentrations. This study may provide a promising alternative technique that reduces economic operation costs in solving wastewater contamination problems.

The presence of colonial and solitary ciliated peritrichous protozoa was determined in a Sequencing Batch Reactor system filled with tezontle, a volcanic rock, economic, and abundant material that can be found in some parts of the world, like Mexico. The presence of these protozoa was related to the removal efficiencies of organic matter. Also, two novel staining techniques are proposed for staining both colonial and solitary peritrichous protozoa. The results show that tezontle promotes the growth of solitary and colonial ciliated peritrichous protozoa, which, once identified, could be used as indicators of the efficiency of the wastewater treatment process. Additionally, the staining techniques established in the current study allowed the precise observation of protozoan nuclei. They can represent a useful complementary methodology for identifying protozoan species present in water treatment processes, along with the already existing identification techniques. The number and variety of protozoa found in the system may be considered potential bioindicators of water quality during biological treatments.

Advanced nitrogen removal without the addition of external carbon source is challenging in the conventional biological nitrogen removal processes. This study presented a novel anaerobic/aerobic/anoxic sequencing batch reactor (A/O/A SBR) based on endogenous nitrate (NO 3 − –N) respiration to enhance nitrogen removal. The mean effluent total nitrogen (TN) in the A/O/A SBR could be reduced to as low as 3.5 mg/L, when the average influent TN and chemical oxygen demand (COD) were 52.7 and 235.4 mg/L, respectively. This advanced nitrogen removal was attributed to the post-denitrification, since 82.7% of TN removal was achieved in the post-anoxic stage. The post-denitrification rate with nitrite (NO 2 − –N, 0.59 mg NO 2 − –N/gMLVSS/h) was higher than that with NO 3 − –N (0.35 mg NO 3 − –N/gMLVSS/h). Therefore, the post-anoxic time could be further optimized by achieving denitrification via NO 2 − –N. The A/O/A SBR has good potential in achieving advanced nitrogen removal, especially in nitrogen-sensitive rural areas.

A three-stage anaerobic sequencing batch reactor system was developed as a new anaerobic process with an emphasis on methane production from ethanol wastewater. The three-stage anaerobic sequencing batch reactor system consisted of three bioreactors connected in series. It was operated at 37 °C with a fixed recycle ratio of 1:1 (final effluent flow rate to feed flow rate) and the washout sludge from the third bioreactor present in the final effluent was allowed to be recycled to the first bioreactor. The pH of the first bioreactor was controlled at 5.5, while the pH values of the other two bioreactors were not controlled. Under the optimum chemical oxygen demand loading rate of 18 kg/m3d (based on the feed chemical oxygen demand load and total volume of the three bioreactors) with a bioreactor volumetric ratio of 5:5:20, the system provided the highest gas production performance in terms of yields of both hydrogen and methane and the highest overall chemical oxygen demand removal. Interestingly, the three-stage anaerobic sequencing batch reactor system gave a much higher energy production rate and a higher optimum chemical oxygen demand loading rate than previously reported anaerobic systems since it was able to maintain very high microbial concentrations in all bioreactors with very high values of both alkalinity and solution pH, especially in the third bioreactor, resulting in sufficient levels of micronutrients for anaerobic digestion.

Algal growth, nutrient removal and settling efficiency were quantified while inoculating sequencing batch reactors with a mixture of microalgae and bacteria (activated sludge). Three algae/bacteria inoculation ratios (5:1, 1:1 and 1:5) as well as pure algal biomass (control) were assessed. Algal biomass production increased with the addition of activated sludge. However, the addition of too much activated sludge can cause disturbance to the Al-Bac biomass growth and algal bacterial processes. All reactors including the control with only algae showed similar settling and nutrient removal efficiencies. Good settling was observed in all reactors with only 5% of total biomass found in supernatant after 1 h of settling. Removal efficiencies of COD, TN and PO4-P in all reactors were 79–82%, 61–65% and 15–37%, respectively, with the lowest phosphorus removal efficiency belonging to 1:5 algae/activated sludge ratio. These results may be due to both long hydraulic (7 days) and solids retention times (up to 30 days). Finally, Al-Bac biomass with 1:1 inoculation ratio showed the best enhancement in terms of biomass growth and algal activities.

High-salinity wastewater is often difficult to treat by common biological technologies due to salinity stress on the bacterial community. Electricity-assisted anaerobic technologies have significantly enhanced the treatment performance by alleviating the impact of salinity stress on the bacterial community, but electricity-assisted aerobic technologies have less been reported. Herein, a novel bio-electrochemistry system has been designed and operated in which a pair of stainless iron mesh-graphite plate electrodes were installed into a sequencing batch reactor (SBR, designated as S1) to strengthen the performance of saline petrochemical wastewater under aerobic conditions. The removal efficiency of phenol and chemical oxygen demand (COD) in S1 were 94.1 and 91.2%, respectively, on day 45, which was clearly higher than the removal efficiency of a single SBR (S2) and an electrochemical reactor (S3), indicating that a coupling effect existed between the electrochemical process and biodegradation. A certain amount of salinity (≤8000 mg/L) could enhance the treatment performance in S1 but weaken that in S2. Illumina sequencing revealed that microbial communities in S1 on days 45 and 91 were richer and more diverse than in S2, which suggests that electrical stimulation could enhance the diversity and richness of the microbial community, and reduce the negative effect of salinity on the microorganisms and enrich some salt-adapted microorganisms, thus improve the ability of S1 to respond to salinity stress. This novel bio-electrochemistry system was shown to be an alternative technology for the high saline petrochemical wastewater.

The stable and efficient operation of the activated sludge sequencing batch reactor (ASSBR) in heavy oil refineries has become an urgent necessity in wastewater biotreatment. Hence, we constructed a green and efficient solid bioaugmentation agent (SBA) to enhance the resistance of the reactor to loading shock. The impact of bioaugmentation on the performance and microbial community dynamics under three patterns of heavy oil refinery wastewater (HORW) loading shock (higher COD, higher toxicity, and higher flow rate) was investigated on an industrial-scale ASSBR. Results showed that the optimal SBA formulation was a ratio and addition of mixed bacteria Bacillus subtillis and Brucella sp., of 3:1 and 3.0%, respectively, and a glucose concentration of 5.0 mg/L. The shock resistance of ASSBR was gradually enhanced and normal performance was restored within 6–7 days by the addition of 0.2% SBA. Additionally, the removal efficiency of chemical oxygen demand and total nitrogen reached 86% and 55%, respectively. Furthermore, we found that Burkholderiaceae (12.9%) was replaced by Pseudomonadaceae (17.1%) in wastewater, and Lachnospiraceae (25.4%) in activated sludge was replaced by Prevotellaceae (35.3%), indicating that the impact of different shocks effectively accelerated the evolution of microbial communities and formed their own unique dominant bacterial families.