Wastewater In Sequencing Batch Reactor Research Articles

Treatment and Handling of Hydraulic Shock Load of Urea Fertilizer Wastewater in Sequencing Batch Reactor

The production process in the urea fertilizer industry produces wastewater with a very high ammonia content, which exceeds the quality standards for fertilizer wastewater. Therefore, it is necessary to treat urea fertilizer wastewater, which has a high ammonia content. One of the technologies that can be used to treat this type of wastewater is the Sequencing Batch Reactor (SBR) technology. The SBR technology was chosen because it only requires one reactor for the entire process, in which in conventional activated sludge systems it occurs in several reactors. Shock loading often occurs in wastewater treatment plants, including both organic shock loads and hydraulic shock loads. The waste used in the SBR operation in this research is urea fertilizer wastewater originating from a urea fertilizer industry in West Java, Indonesia. The parameters to be tested were COD, MLVSS, DO, pH, temperature, turbidity, and ammonia concentration. The results showed that the efficiency of reducing ammonia levels under normal loading with a flow rate of 300 mL/day was 99.5%, whereas when given a shock load of 600 mL/day, an efficiency of 98% was obtained. This proves that SBR can handle shock loads even though its efficiency slightly decreases.

Effect of Organic Loading Rates on Performance of Treating Dairy Wastewater in a Lab-Scale Sequencing Batch Reactor

This study aims to investigate, the effect of organic loading rates (OLRs), nutrient ratio addition, and sludge retention time (SRT) on treating dairy wastewater in a sequencing batch reactor (SBR) system. This investigation is verified by experiments conducted in 3 phases at 3 different OLRs (1.8, 1.2, and 0.9 kg/m3d, respectively). Urea ((NH2)2CO) is added to make a suitable (COD:N:P) ratio of (100:5:1) in dairy wastewater. The SRT is adjusted from 50 days to an appropriate value of 18 days. The obtained results show that the COD, TN, and TP removal efficiencies are increased with decreasing OLRs. Sludge concentration in the SBR tank is stable at 1100 mg/L after adding (NH2)2CO. In addition, the SBR operated at a suitable SRT (i.e. 18 days) helps the biomass stably, resulting in enhancement of COD, TN, and TP removal. The results are helpful to the design of SBR for treating dairy wastewater.

Biochar immobilized petroleum degrading consortium for enhanced granulation and treatment of synthetic oil refinery wastewater

This study investigated the effect of biochar immobilized consortium for enhanced biotreatment of oil refinery wastewater in sequencing batch reactors. The control reactor (R0), and reactors with free bacterial consortium (R1), biochar (R2) and biochar immobilized consortium (R3) were operated in parallel. Results illustrated that granulation was faster in R2 and R3, the proportion of granules >0.45 mm was almost 30% higher than the R0 and R1 during the first 45 days. R3 exhibited optimum operational performance as highest removal efficiencies of COD (97.9%), oil (97.4%), NH4+-N (97.2%) and TN (90.2%) at the end of the experiment. Biochar enriched microbial richness and diversity whereas inoculated consortium positively modulated the community structures. Higher abundance of inoculated Rhodococcus (4.81%) bacteria in R3 suggested successful formation of functional strains in the granular sludge. It concludes that the application of biochar immobilized consortium is a better choice for the treatment of refinery wastewater.

Co-metabolism of olive mill wastewater in sequencing batch reactor under aerobic conditions after Fenton-based oxidation

The study explored the experimental conditions to enable co-metabolism of olive mill wastewater, (OMW), pretreated by Fenton-based oxidation, when combined with a compatible waste in a sequencing batch reactor (SBR). For this purpose, peptone mixture was used as the synthetic substrate, well tested for its similar biodegradation character with sewage. Emphasis was placed upon the degree of dilution that could be afforded without upsetting the performance of biological process. The SBR operation involved four cycles a day, at a sludge age of 8.0 days. The COD level of the peptone mixture feeding was kept constant as 400 mg/L, to simulate a relatively weak sewage. After acclimation of biomass to the synthetic substrate, SBR operation continued for 105 days with gradually increasing OMW additions in four consecutive phases with COD increments between 40 and 100 mg/L and no OMW addition in the last phase. Co-metabolism with complete removal of biodegradable COD in OMW could be sustained under cyclic steady-state conditions of each phase. Biodegradation characteristics of OMW could be defined in terms of COD fractionation and process kinetics; they were used in model simulation of in-cycle COD profiles at the end of each cycle. The study advocated co-metabolism as a novel and sustainable approach of wastewater management of olive mill wastewater, when properly diluted in sewage or a compatible wastewater and jointly subjected to biological treatment, a pre-requisite for OMW. It is believed that the proposed approach embodies all scientific and practical attributes to provide the long-awaited solution for this industry.

Emission characteristics of odorous volatile sulfur compound from a full-scale sequencing batch reactor wastewater treatment plant.

Volatile sulfur compounds (VSCs) generated and discharged as air pollutants from wastewater treatment plants (WWTPs) pose a threat to human health and the environment. This study characterized VSC emissions from a full-scale sequencing batch reactor (SBR) WWTP at the water-air interface for one year. Results demonstrated that higher ambient temperatures and aeration contributed significantly to VSC emissions as the highest emissions occurred over summer during the feeding synchronous aeration period. VSC emissions were related to chemical oxygen demand and sulfate concentrations in wastewater, and empirical formulas based on these values were proposed that can be used to model VSC emission fluxes from SBR WWTP. VSC emission factors (μg·ton-1 wastewater) throughout the SBR treatment process were: 361±101 hydrogen sulfide (H2S), 82±76 methyl mercaptan (MT), 61±31 dimethyl sulfide, 17±5 carbon disulfide, and 46±24 dimethyl disulfide. H2S and MT were the dominant odors released. Findings from this study may be applicable for calculating VSC emissions during SBR wastewater treatment stages, and may be beneficial for determining methods and strategies to reduce VSCs.

The Impact of an Ultrasonic Field on the Efficiency of Coke Wastewater Treatment in a Sequencing Batch Reactor

The growing production of coke and, consequently, coke wastewater is a significant problem for the environment. Coke wastewater, because it contains high amounts of toxic substances, is classified as an extremely hazardous industrial wastewater. The treatment of such wastewater requires a combination of advanced physicochemical and biological methods. The aim of the research was to investigate the effectiveness of the application of the ultrasonic disintegration of coke wastewater in a sequencing batch reactor (SBR). The tests were conducted in two stages, wherein the first stage involved determining the most favorable sonication conditions, that is, time and amplitude. The authors used the following amplitudes: 31 µm; 61.5 µm; 92 µm; 123 µm and times: 120 s; 240 s; 480 s; 960 s. The second stage focused on treating coke wastewater in SBRs (Reactor A—a proportion of coke wastewater in the mixture: 5%, 10%, and 20%; reactor B—sonicated coke wastewater, proportion in mixture: 5%, 10%, 20%). The efficiency of the treatment process was determined based on the rate of removal of selected parameters: chemical oxygen demand (COD), total organic carbon (TOC), inorganic carbon (IC), ammoniacal nitrogen (N-NH4), total nitrogen (TN), the course of pH changes. The study revealed that sonication of coke wastewater increased biodegradability and reduced its toxicity. The use of the preliminary sonication of coke wastewater before biological treatment improved the degree of removal of the tested parameters by approximately 10%. The volumetric ratio of coke wastewater in the mixture had the greatest impact on the obtained results. The use of an ultrasound field allows the treatment process to be executed with a coke wastewater addition exceeding 10%. In addition, it was found that in order to increase the coke wastewater treatment efficiency, one should optimize individual phases in the SBR and the pollution load.

Novel approach to improving wastewater treatment and sewage sludge combustion using pulverized coal-activated sludge.

Sewage and sludge are usually treated separately. Considering improving sludge treatment while improving sewage treatment is beneficial to the synergetic effect of sewage treatment and sludge treatment. The efficiency of pulverized coal-activated sludge (PAS) on contaminant removal, sludge calorific value, and combustion characteristic was investigated in contrast to conventional activated sludge (CAS) using the laboratory-scale sequencing batch reactor (SBR). Results indicated that the average chemical oxygen demand, ammonium nitrogen, total nitrogen, and total phosphorus removal efficiency of PAS were highest under a dosage of 0.4g/L, which were 98.56%, 94.22%, 68.60%, and 95.96%, respectively. The average effluent concentration satisfied the Level A discharge standard of pollutants for municipal wastewater treatment plants (GB18918-2002). The calorific value and maximum weight loss of PAS gradually increased adjusting the dosage of pulverized coal. At the pulverized coal dosage of 0.2g/L, the calorific value of PAS with 70% water content is 3,824.07kJ/kg, which can satisfy the requirement of self-maintained combustion. Overall, the pulverized coal can simultaneously improve the treatment of wastewater in SBR and promote the sludge combustion by increasing calorific value. Therefore, PAS system is an innovation based on improving the sewage treatment sludge combustion. PRACTITIONER POINTS: An innovative method to simultaneously improving wastewater treatment and sewage sludge combustion using pulverized coal-activated sludge was developed. The average COD, , TN, and TP removal efficiency of PAS-0.4 is best. The 70% moisture content sludge calorific values of 3,824.07kJ/kg in PAS-0.2 can satisfy the requirement of self-maintained combustion.

Enhancing nitrogen removal from wastewater in sequencing batch reactors (SBRs) using additional carbon source produced from food waste acidogenic fermentation at different temperatures.

Fermentation slurry from food waste (FSFW) produced at different temperatures (20, 37, and 55°C) was utilized as external carbon source for promoting nitrogen removal in this study. It was found that high temperatures improved the hydrolysis rate by promoting the hydrolytic enzyme activity. Mesophilic temperature (37°C) was favorable for organic acid (especially lactic acid) production by selectively enriching the Lactobacillus (with a relative abundance of 90.6%), while thermophilic temperature (55°C) would restrict the acidogenesis rate (18.9%) and result in the accumulation of carbohydrate in the fermented slurry. Organic acids in the FSFW act as easily biodegradable carbon sources, but the macromolecular and particulate organic components can be utilized as slowly biodegradable carbon sources in the denitrification processes. Using the FSFW as carbon sources to enhance nitrogen removal from wastewater in sequencing batch reactors (SBRs) for more than 150days, the FSFW produced at thermophilic temperature could significantly promote the microbial metabolic capacity of the activated sludge and improve the nitrogen and phosphate removal efficiencies.

Effect of SRT on Stability of Yeast-SBR in Treating Oil-containing Wastewater

Sludge retention time(SRT) is a crucial parameter to influence the stability of biological wastewater treatment systems. Especially, the effects of SRT on yeast-wastewater treatment remain unclear. In this study, mixtures of yeast strains were applied to treat oil-containing wastewater in sequencing batch reactors(SBR) and the effects of sludge retention time(SRT as 5, 10, 20, 40 d) on the removal efficiency of pollutants, contents and composition of extracellular polymeric substances(EPS), yeast cells settleability and yeast communities were investigated. The results showed that the recommended SRT was 5-10 d for the yeast-SBR system; Higher SRT led to decrease of COD removal rate and content of EPS; the tightly-bounded EPS was the major one which consisted of polysaccharides. SRT of 5-40 d had no significant effects on the SVI of yeast cells, however, longer SRT (>20 d) resulted in the increase of mycelial cells and a tendency to produce the filamentous bulking. In the continuous operation of SBR, three extraneous yeast strains capable of utilizing or degrading oil were identified in the systems under the short and long SRT. To conclude, shorter SRT was favorable for the system stability in treating oil-containing wastewater by yeasts.

Effect of aeration rate on performance and stability of algal-bacterial symbiosis system to treat domestic wastewater in sequencing batch reactors

This study investigated aeration rate (0, 0.2, 0.4 and 1.0L/min) effects on algal-bacterial symbiosis (ABS) and conventional activated sludge (CAS) systems while treating domestic wastewater in sequencing batch reactors. Experiment results showed that ABS system performed better on NH4+-N, total nitrogen and total phosphorus removal than CAS system, especially under lower aeration rate condition (0.2Lair/min), with removal efficiencies improvements of 18.90%, 12.45% and 46.66%, respectively. The mechanism study demonstrated that a favorable aeration rate reduction (half of traditional value in CAS system) could enhance algae growth but weaken hydraulic shear force, which contributed to the interactions between algae and sludge flocs and further stability of ABS system. In addition, algae growth protected both ammonia and nitrite oxidizing bacteria from optical damage. It is expected that the present study would provide some new insights into ABS system and be helpful for development of low-energy demand wastewater treatment process.

Co-treatment of old landfill leachate and municipal wastewater in sequencing batch reactor (SBR): effect of landfill leachate concentration

Sequencing batch reactor (SBR) was assessed for direct co-treatment of old landfill leachate and municipal wastewater for chemical oxygen demand (COD), nutrients and turbidity removal. Nitrogen removal was achieved by sequential nitrification and denitrification under post-anoxic conditions. Initially, SBR operating conditions were optimized by varying hydraulic retention time (HRT) at 20% (v/v) landfill leachate concentration, and results showed that 6 d HRT was suitable for co-treatment. SBR performance was assessed in terms of COD, ammonia, nitrate, phosphate, and turbidity removal efficiency. pH, mixed liquor suspended solids, mixed liquor volatile suspended solids (MLVSS), and sludge volume index were monitored to evaluate stability of SBR. MLVSS indicated that biomass was able to grow even at higher concentrations of old landfill leachate. Ammonia and nitrate removal efficiency was more than 93% and 83%, respectively, whereas COD reduction was in the range of 60–70%. Phosphate and turbidity removal efficiency was 80% and 83%, respectively. Microbial growth kinetic parameters indicated that there was no inhibition of biomass growth up to 20% landfill leachate. The results highlighted that SBR can be used as an initial step for direct co-treatment of landfill leachate and municipal wastewater.

Kinetic Modeling for Simultaneous Organic Carbon Oxidation, Nitrification, and Denitrification of Abattoir Wastewater in Sequencing Batch Reactor

ABSTRACTA laboratory-scale study was conducted in a 20.0-L sequencing batch reactor (SBR) to explore the feasibility of simultaneous removal of organic carbon and nitrogen from abattoir wastewater. The reactor was operated under three different combinations of aerobic-anoxic sequence, viz., (4+4), (5+3), and (5+4) h of total react period, with influent soluble chemical oxygen demand (SCOD) and ammonia nitrogen (NH4+-N) level of 2200 ± 50 and 125 ± 5 mg L−1, respectively. In (5+4) h cycle, a maximum 90.27% of ammonia reduction corresponding to initial NH4+-N value of 122.25 mg L−1 and 91.36% of organic carbon removal corresponding to initial SCOD value of 2215.25 mg L−1 have been achieved, respectively. The biokinetic parameters such as yield coefficient (Y), endogenous decay constant (kd), and half-velocity constant (Ks) were also determined to improve the design and operation of package effluent treatment plants comprising SBR units. The specific denitrification rate (qDN) during anoxic condition was estimated as 6.135 mg N/g mixed liquor volatile suspended solid (MLVSS)·h on 4-h average contact period. The value of Y, kd and Ks for carbon oxidation and nitrification were found to be in the range of 0.6225–0.6952 mg VSS/mg SCOD, 0.0481–0.0588 day−1, and 306.56–320.51 mg L−1, and 0.2461–0.2541 mg VSS/mg NH4+-N, 0.0324–0.0565 day−1, and 38.28–50.08 mg L−1, respectively, for different combinations of react periods.

Treatment of agro based industrial wastewater in sequencing batch reactor: Performance evaluation and growth kinetics of aerobic biomass

A sequencing batch reactor (SBR) with a working volume of 8 L and an exchange ratio of 25% was used to enrich biomass for the treatment of the anaerobically treated low pH palm oil mill effluent (POME). The influent concentration was stepwise increased from 5000 ± 500 mg COD/L to 11,500 ± 500 mg COD/L. The performance of the reactor was monitored at different organic loading rates (OLRs). It was found that approximately 90% of the COD content of the POME wastewater was successfully removed regardless of the OLR applied to the SBR. Cycle studies of the SBR show that the oxygen uptake by the biomass while there is no COD reduction may be due to the oxidation of the storage product by the biomass. Further, the growth kinetic parameters of the biomass were determined in batch experiments using respirometer. The maximum specific growth rate (μmax) was estimated to be 1.143 day−1 while the half saturation constant (Ks) with respect to COD was determined to be 0.429 g COD/L. The decay coefficient (bD) and biomass yield (Y) were found to be 0.131 day−1 and 0.272 mg biomass/mg COD consumed, respectively.

Aerobic granules formation and simultaneous nitrogen and phosphorus removal treating high strength ammonia wastewater in sequencing batch reactor

The objective of this study was to evaluate aerobic granules formation and simultaneous nitrogen and phosphorus removal treating high strength ammonia wastewater in sequencing batch reactor (SBR). After successful aerobic granulation, mixed liquor suspended solids (MLSS) concentrations of the SBR increased from 3.11 to 14.52g/L, while sludge volume index (SVI) values decreased from 144.61 to 30.32mL/g. Protein (PN) and polysaccharide (PS) concentrations increased from 60.2 and 12.5mg/L to 101.1 and 15.8mg/L, respectively. Simultaneous nitrogen and phosphorus removal was enhanced by altering the influent chemical oxygen demand/nitrogen (COD/N) ratio. At COD/N ratio of 9, total nitrogen (TN) and total phosphorus (TP) removal efficiencies were up to 89.8% and 77.5%, respectively. Three-dimensional excitation–emission matrix (3D-EEM) spectroscopy showed that the chemical compositions of sludge EPS were changed during granulation process. The results could provide useful information to promote nitrogen and phosphorus removal using aerobic granular sludge technology.

A Novel Predictive PID Control Method for SBR Wastewater Treatment Process DO Control

Sequencing Batch Reactor (SBR) wastewater treatment process has lots of characteristics, such as randomness, time-varying characteristics, complexity and so on. In order to solve the above problems, a predictive PID control method based on DMC and ordinary PID for SBR wastewater treatment process dissolved oxygen (DO) control was proposed. The simulation studies were conducted with the MATLAB in a sewage treatment plant. The results showed that the proposed predictive PID control method was robust and jamproof. Meanwhile, the wastewater treatment system also had a strong capacity of shock load.

Comparison of partial nitrification to nitrite for ammonium-rich organic wastewater in sequencing batch reactors and continuous stirred-tank reactor at laboratory-scale

The combined partial nitrification/Anammox process is especially suitable for the treatment of influents with low C/N ratio. However, many nitrogenous wastewater are also rich in organics. Two systems (continuous stirred-tank reactor (CSTR) and sequencing batch reactor (SBR)) are commonly used to achieve nitrite accumulation, but no complete comparison between these two systems for treating different wastewater has been reported. The objective of this paper was to compare the partial nitrification in CSTR and SBR for the treatment of ammonium-rich organic wastewater. The result showed that it took a shorter time to startup partial nitrification in CSTR, but SBR was a better option for treating ammonium-rich organic wastewater with C/N lower than 0.34. With increase HRT to 48 h, excellent nitrite accumulation could be achieved in both reactors for wastewater containing landfill leachate. For subsequent anammox, CSTR was more suitable when leachate percentage ranged from 35% to 40%.

Treatment of opium alkaloid containing wastewater in sequencing batch reactor (SBR)—Effect of gamma irradiation

Aerobic biological treatment of opium alkaloid containing wastewater as well as the effect of gamma irradiation as pre-treatment was investigated. Biodegradability of raw wastewater was assessed in aerobic batch reactors and was found highly biodegradable (83–90% degradation). The effect of irradiation (40 and 140 kGy) on biodegradability was also evaluated in terms of BOD 5/COD values and results revealed that irradiation imparted no further enhancement in the biodegradability. Despite the highly biodegradable nature of wastewater, further experiments in sequencing batch reactors (SBR) revealed that the treatment operation was not possible due to sludge settleability problem observed beyond an influent COD value of 2000 mg dm −3. Possible reasons for this problem were investigated, and the high molecular weight, large size and aromatic structure of the organic pollutants present in wastewater was thought to contribute to poor settleability. Initial efforts to solve this problem by modifying the operational conditions, such as SRT reduction, failed. However, further operational modifications including addition of phosphate buffer cured the settleability problem and influent COD was increased up to 5000 mg dm −3. Significant COD removal efficiencies (>70%) were obtained in both SBRs fed with original and irradiated wastewaters (by 40 kGy). However, pre-irradiated wastewater provided complete thebain removal and a better settling sludge, which was thought due to degradation of complex structure by radiation application. Degradation of the structure was observed by GC/MS analyses and enhancement in filterability tests.

Nitrogen removal from slaughterhouse wastewater in a sequencing batch reactor under controlled low DO conditions

The aim of this study was to examine nitrogen removal from slaughterhouse wastewater in a laboratory-scale sequencing batch reactor (SBR) operated at low dissolved oxygen (DO) levels under two aeration strategies: intermittent aeration (IA) and continuous aeration (CA). Under the IA strategy, during the aeration periods, the maximum DO was controlled at 10% saturation; under the CA strategy, in the first hour of the react phase, the DO was maintained at 10% saturation, and then it was kept at 2-3% saturation in the remaining react phase. Total nitrogen removals of up to 95 and 91% were achieved under the IA and CA aeration strategies, respectively. It is proposed that in situ measurement of oxygen utilization rates can be used to control the operation of SBRs for nitrogen removal.

Experiments for modelling the biodegradation of wastewater in sequencing batch reactors

Three types of wastewater were considered: typical municipal wastewater and the effluent of a dairy industry, both polluted with organic carbon and nitrogen, and wastewater typical of a chemical industry, containing toxic or recalcitrant compounds (4-chlorophenol). Sequencing batch reactors (SBRs) were considered. Process experiments were performed to provide experimental data for parameter identification of the dynamical models of the SBRs. The processes were instrumented with sensors to measure O2, NH3, T, pH, OUR, and other off line measurements (e.g.: NO2 − and NO3 −, COD, phenol concentration, microbiological counts and activities) in order to study more accurately the behaviour of the biomasses. However, the general idea is to design a system with a minimal number of sensors.

Aerobic granulation with industrial wastewater in sequencing batch reactors

Granular sludge formation was promoted in two laboratory scale sequencing batch reactors (SBRs), R1 and R2 fed with industrial wastewater produced in a laboratory for analysis of dairy products. Both reactors were operated under similar conditions during most of the experimental period. However, an anoxic phase between 10 and 30 min was included at the beginning of every cycle of operation of R1, but not in R2. Organic and nitrogen loading rates applied to both systems were high, up to 7 g COD/(L d) and 0.7 g N/(L d). Nitrogen removal efficiency was 70% in both units even considering that R2 was operated always under aerobic conditions. Granules with similar morphology were developed in both systems. Size distribution was comprehended between 0.25 and 4.0 mm for both systems. The presence of TSS in the effluent of the SBRs was strongly affected by either the length of the withdrawal period or by the particulated COD to biomass ratio (CODp/VSS) applied to the systems. The lower concentrations of TSS in the effluent were attained when the systems were operated with a CODp/VSS ratio lower than 0.12 g COD/g VSS. There was a strong reduction of the average TSS content in the effluent from 450 to 200 and 150 mg TSS/L when the length of the withdrawal period was diminished sequentially from 3 to 1 and 0.5 min, respectively. This was caused by a more intensive washout of small suspended biomass aggregates that took place when the length of this period was shortened.