Upflow Sludge Blanket Reactor Research Articles

Emerging contaminants in conventional and advanced biological nutrient removal based wastewater treatment plants in India- insights into the removal processes

Emerging contaminants (ECs) in the environment are a cause of concern due to their potential toxic effects. The study investigates the fate of 20 ECs covering a wide range of physical-chemical properties in ten full-scale municipal wastewater treatment plants (WWTPs). The plants were based on conventional technologies such as waste stabilization pond, upflow sludge blanket reactor, activated sludge process, and biological nutrient removal-based technologies such as anoxic-aerobic process, anaerobic-anoxic-aerobic process, biodenipho process, sequencing batch reactor, and densadeg-biofor process. Covering all the wastewater and sludge treatment lines, the mass balance approach was followed to investigate the fate of ECs at each treatment stage. The amount of ECs entering and leaving the WWTPs ranged from 0.82 to 11.94 kg/day and 0.027 to 0.70 kg/day, respectively. Antibiotics showed limited removal and were detected in the 0.006 to 0.18 kg/day range. The ECs were mainly detected in the aqueous phase in all the treatment steps. However, the contribution from the particulate and sludge phase cannot be neglected. The sorption of ECs on sludge depended on the sludge's characteristics. It was found to be the highest in the primary sludge. The measured sorption coefficient indicated that both hydrophobic and electrostatic interactions of ECs with the sludge are insufficient in explaining the sorption behaviour of a contaminant. The mass balance studies show biodegradation as the major removal pathway in all the WWTPs. The study provides the environmental mass load of ECs from Indian WWTPs. It will help understand the removal mechanisms of ECs in different types of wastewater treatment techniques.

Bioenergy recovery potential from upflow microaerobic sludge blanket reactor fed with swine wastewater

This paper reports the bioenergy recovery potential inherent to swine wastewater (SWW) when treated in an upflow microaerobic sludge blanket reactor (UMSB) operating with different oxygen loads. The UMSB reactor performance was compared with the one achieved with an upflow anaerobic sludge blanket (UASB) reactor that worked as a control. The biogas production was measured on a lab scale and used to estimate the UMSB reactor self-sufficiency energy. The highest methane yield achieved in the UMSB reactor was 228.6 NL kgCOD−1 d−1 at an organic loading rate (OLR) of 12.2 kgCOD m−3d−1 (HRT of 10 h). Both OLR and air dose increase generated methane dilution in the biogas, which reduced the possibility of electrical energy recovery. Nevertheless, the results showed that the UMSB reactor was self-sufficient and had energy efficiency at the 12 h HRT with doses of 0.17 and 0.25 LO2 Lfeed−1d−1 and at the 10 h HRT with a dose of 0.25 LO2 Lfeed−1d−1. The UMSB reactor achieved an energy return on investment (EROI) of 11.6–18.7, showing a potentially viable alternative for power generation.

Insight into nitrogen removal performance of anaerobic ammonia oxidation in two reactors: Comparison based on the aspects of extracellular polymeric substances and microbial community

Anaerobic ammonium oxidation (Anammox) is expected to play a promising role in treating low C/N ratio wastewater. In this study, nitrogen removal performance and the effects of extracellular polymeric substances (EPS) on anammox activity were investigated in two different reactors, followed by analysis of 16S rRNA high-throughput sequencing. A sequencing batch reactor (SBR) and an up-flow anammox sludge blanket reactor (UASB) operated for 133 days, with total nitrogen removal efficiencies of 82.09 ± 4.76% and 87.91 ± 2.59% in the phase 3, respectively. The EPS concentration in UASB was about 1.6 times higher than that in SBR. Also, in the batch tests, especially the anammox-EPS of UASB (AU-EPS) additions contributed to better nitrogen removal capability for anammox bacteria (AnAOB). The relative abundance of AnAOB in UASB was observed to reach 19.68% in the end, accounting for a relatively high degree in the whole community. In SBR, the effluent NH4+-N concentration increased when increasing the substrate concentration, followed by the decrease of the relative abundance of AnAOB. Thus, the different feeding strategies would lead to different granulation styles, further influencing the activity and stability of anammox system. This research aims to get a better understanding of the different mechanisms associated with AnAOB enrichment strategies.

Application of a Sludge Blanket Reactor for Effluent Treatment: A Laboratory Study

Energy is required in all societies worldwide. This led to a dependency of fossil fuel. During uncertain times fossil fuel supply become highly politically and used as an influencing source. This requires establishing a more environmentally friendly processes to decrease dependency. To produce biogas from municipal, agricultural and industrial waste a laboratory benchtop up-flow sludge blanket reactor with a operating volume of 2850 ml was designed build, started up, and operated using prepared municipal wastewater and separated liquid cow manure at a hydraulic retention time of 1 day, 3 days and 6 days after an 120 h adjustment time prior to testing.
 While using wastewater as influent, the laboratory benchtop up-flow sludge blanket reactor system was not able to reduce the chemical oxygen demand content significantly. Especially at a high volumetric flow rate for the 1-day hydraulic retention time. The produced gas amount decreased from 0.59 ±0.07 (ml/h)/L at a hydraulic retention rate of 6 days to 0.042 ±0.04 (ml/h)/L. The fluctuating influent chemical oxygen demand of 25 ±1 mg/L to 74 ±15 mg/L resulted in a stable effluent concentration of 39 ml/L and 45 ±11 mg/L respectively.
 The laboratory benchtop up-flow sludge blanket reactor system with separated liquid cow manure showed a higher chemical oxygen demand degradation capability but resulted in higher chemical oxygen demand in the effluent. The influent chemical oxygen demand of 308 ±42 mg/L was broken downs to 59 ±1 mg/L at a hydraulic retention time of 6 days and to 114 ±5 mg/L for 1 day retention time. The biogas production result in a stable gas production rate of 0.27 ±0.02 (ml/h)/L through all three hydraulic retention times. For both the wastewater and separated liquid cow manure operation the biogas without carbon dioxide was between 55 and 65%.
 The results show that the laboratory benchtop up-flow sludge blanket reactor system can reduce high chemical oxygen demand in wastewater and separated liquid cow manure. However, a minimum feed level having a minimal chemical oxygen demand above 36 mg/L is needed, otherwise, the active bacterial mass contributes to the effluent level as seen for the influent level below 36 mg/L and 25 mg/L which resulted in a minimum effluent level of 39 mg/L for a hydraulic retention time of 3-days and 6-days.

The effects of anaerobic reactor post-treatments by rapid filtration systems and conventional techniques.

Although anaerobic reactors are an excellent alternative in the treatment of domestic effluents, they have the disadvantage of requiring post-treatment. Many technologies have been studied and, recently, rapid filtration systems have been presented as a viable alternative for post-treatment. This work compared post-treatment techniques for anaerobic upflow sludge blanket (UASB) reactors by rapid filtration systems (double filtration (DF); triple filtration with clinoptilolite (TFc); and triple filtration with activated carbon (TFac)) to conventional systems (facultative pond (FP); biological filter (BF); biological filter with recirculation and decantation (BFD)), verifying their potential for improvement of the final effluent quality. The UASB effluent post-treatments by FP, BF, BFD, DF, TFc, and TFac were evaluated. The removal of turbidity in both BFD and FP post-treatments was below 75%. The DF, TFc, and TFac treatments showed over 99% removal of the same parameters. COD removal in the FP, BF, and BFD post-treatments was over 10%, while in the DF, TFc, and TFac treatments, it was over 80%. The greatest total phosphorus removal was observed in TFc and TFac, whose values were over 99%. The best removal of ammoniacal nitrogen, 99% was observed in the TFc treatment. Regarding Al, Cd, Cr, Cu, Mn, Ni, Pb, and Zn removal, all rapid filtration systems showed better performance when compared to conventional systems. The DF, TFc, and TFac systems showed over 90% removal of most metals evaluated, while the FP and BF treatments presented values below 50% for most metals, and in the BFD system, the removal values were below 80% for most metals. The results indicate that rapid filtration systems were better at removing all evaluated parameters when compared to conventional systems.

Microaerophilic treatment enhanced organic matter removal and methane production rates during swine wastewater treatment: A long-term engineering evaluation

Anaerobic biotechnology has been widely used for swine wastewater (SWW) treatment. However, its organic loading rate (OLR) is far lower than expected, mainly because of the low rate of hydrolysis. In this study, the comparative process performance and efficiency of an up-flow anaerobic sludge blanket (UASB) reactor (R1) and an up-flow microaerobic sludge blanket (UMSB) reactor (R2) were evaluated for SWW treatment, operating for 264 days under higher OLRs and lower hydraulic retention times than those found in the literature. The R2 was subjected to the three different air doses: 0.09 (stage I), 0.17 (stage II), and 0.25 (stage III) LO2 Lfeed−1 d−1 aiming at enhancing the hydrolysis step of the anaerobic digestion (AD). The overall results showed that 0.17 LO2 Lfeed−1 d−1 was the best experimental condition evaluated, which provided volatile suspended solids, total chemical oxygen demand, and particulate chemical oxygen demand removal efficiencies of 85.0 ± 1.9%, 83.8 ± 2.5%, and 82.1 ± 4.8%, respectively. This performance was due to the higher organic matter hydrolysis, resulting in higher methane production. Therefore, the UMSB reactor treatment was demonstrated to be a feasible alternative for SWW, although some strategies to control biomass washout must be investigated.

Effect of salinities on nitrogen removal performance of DHS-USB system and growth of Epinephelus bruneus in closed recirculating aquaculture system

The aim of this study was to evaluate the effect of salinities on the nitrogen removal performance of a pilot-scale down-flow hanging sponge (DHS) reactor and an up-flow sludge blanket (USB) reactor which was installed in a closed recirculating aquaculture system for the purpose to maintain the water quality in the aquaculture tank. In this study, water quality and the growth of the Longtooth grouper, Epinephelus bruneus, were investigated at 30‰, 22.5‰, and 15‰ salinity for over 1000 days. The tested DHS reactor has successfully maintained total ammonium nitrogen in aquaculture tank at less than 1.0 mg-N·L−1 at various salinities. The abundance of nitrifying bacteria detected in the DHS reactor was higher at salinities of 15‰ and 22.5‰ than at 30‰. The USB reactors achieved a nitrate removal efficiency of over 60%. All fish survived all salinity conditions, exhibiting the highest daily weight gain of 2.0 ± 3.4 g-fish·day−1 at 15‰ salinity, which was 1.6 times higher than that at 30‰. The DHS-USB system could exert nitrogen removal under changing salinity conditions.

Nature based solutions for winery wastewater valorisation

To valorise winery treated wastewater and to produce suitable water for the irrigation of vineyards, or other factory operations, the WETWINE project set up a combination of a hydrolytic up-flow sludge blanket (HUSB) reactor and constructed wetlands (CW). The WETWINE plant is located in Tomiño (Pontevedra, Spain) and is being validated at the demo-scale at Santiago Ruiz Winery (NW Spain). The plant consisted of a HUSB reactor for removing suspended solids and hydrolyse organic matter, followed by two vertical subsurface flow constructed wetland (VF) operating in parallel and to provide further treatment, a horizontal subsurface flow constructed wetland (HF) operating in series. After two years of continuous monitoring and regardless in the variation of flow and load, the hybrid system achieved average removal efficiencies of over 93% for total suspended solids and chemical oxygen demand, receiving an overall surface loading of up to 115 g COD/m2·d. Total nitrogen removal reached 62% with an average concertation of 21 mg N/ L. The WETWINE plant was also able to increased the pH in the effluent from 5.5 at the influent to 7.2.

Effect of carbon-to-nitrogen ratio on high-rate nitrate removal in an upflow sludge blanket reactor for polluted raw water pre-treatment application

The drinking water treatment plants (DWTPs) in the developing countries urgently need an efficient pre-treatment for nitrate (NO3−) removal to cope with the increasing NO3− pollution in raw water. An upflow sludge blanket (USB) reactor applied for NO3− removal from domestic wastewater may be adopted by the DWTPs. However, studies on the optimal carbon-to-nitrogen ratio (C/N) and operation of USB reactor at short hydraulic retention times (HRT) for high-rate polluted raw water pre-treatment are lacking. In this study, we first investigated the optimal C/N for biological NO3− removal in a sequencing batch reactor (SBR). An USB reactor was then operated with the optimal C/N for pre-treating synthetic raw water contaminated with NO3− (40 mg N L− 1) to monitor the NO3− removal performance and to examine opportunities for reducing the HRT. After operating the SBR with designed C/N of 4, 3 and 2 g C g− 1 N, we selected C/N of 3 g C g− 1 N as the optimal ratio due to the lower carbon breakthrough and nitrite (NO2−) accumulation in the SBR. The USB reactor achieved complete NO3− and NO2− removal with a lower designed C/N of 2 g C g− 1 N due to the longer sludge retention time when compared with that of SBR (10 d). The high specific denitrification rate (18.7 ± 3.6 mg N g− 1 mixed liquor volatile suspended solids h− 1) suggested a possible HRT reduction to 36 min. We successfully demonstrated an USB reactor for high-rate NO3− removal, which could be a promising technology for DWTPs to pre-treat raw water sources polluted with NO3−.

Occurrence and removal of micropollutants in full-scale aerobic, anaerobic and facultative wastewater treatment plants in Brazil

This study aims to evaluate micropollutant occurrence and removal in a low-middle income country (LMIC) by investigating the occurrence of 28 chemicals from different classes (triclosan, 15 polycyclic aromatic hydrocarbons (PAHs), 4 estrogens and 8 polybrominated diphenyl ether (PBDE) congeners) in three technologically diverse full-scale Brazilian wastewater treatment plants (WWTPs). These chemicals were detected at concentrations similar to those reported in other low-middle income countries (LMICs) and high-income countries (HICs) (0.1–49 μg/L) indicating their widespread use globally and the need for more studies in LMICs that are typically characterized by relatively inadequate wastewater treatment barriers. Among the three different WWTPs investigated for removal of these chemicals, the least energy intensive system, waste stabilization ponds (WSPs), was the most effective (95–99%) compared to the activated sludge (79–94%), and Up-flow sludge blanket reactor (UASB) with trickling filters system (89–95%). These results highlight the potential of WSPs for micropollutant removal-especially in warm climates. However, the effluent from all three WWTP could pose a risk to aquatic organisms when discharged into the receiving waters as the effluent concentrations of triclosan, some estrogens, PAHs and BDE 209 were above European environmental quality standards (EQS) or predicted no effect concentration (PNEC values), indicating that receiving water bodies could benefit from further treatment. In combination, these results help to further understand prevailing concentrations of micropollutants globally and fate in current wastewater treatment systems.

Comparison of complete nitritation–denitrification and partial nitritation–anammox for iron oxide wastewater treatment

Cost-effective nitrogen removal from iron oxide wastewater is a limitation in the sustainable development of the iron oxide manufacturing industry. Two processes, namely, complete nitritation (in a sequencing batch reactor with zeolite powder, ZSBR) combined with traditional denitrification and partial nitritation (in the same ZSBR) combined with anaerobic ammonium oxidation (anammox), were successfully developed and then compared for long-term nitrogen removal from iron oxide wastewater. Stable and complete nitritation with nitrite accumulation ratio (NAR) > 95.1% was achieved in the ZSBR. Nitrogen removal rates (NRRs) of up to 4.083 ± 0.727 kg N/m3/d were obtained subsequently in a denitrifying upflow sludge blanket reactor at an influent chemical oxygen demand/total nitrogen ratio of 2.5. Efficient partial nitritation was also achieved with effluent NO2−–N/NH4+–N ratios of 1.1–1.5 and NAR > 92.0% in the ZSBR, with a final NRR of 1.175 kg N/m3/d in the subsequent anammox reactor. The addition of zeolite achieved persistent free ammonia inhibition on nitrite oxidizing bacteria in the ZSBR and resulted in efficient and controllable nitrite accumulation. The total chemical cost in the complete nitritation–denitrification process was 3.32 USD/kg NH4+–N, which was 1.14 times higher than that in the partial nitritation–anammox process. Both processes were effective and reliable in achieving nitrogen removal from iron oxide wastewater for the sustainable development of the iron oxide manufacturing industry.

Feasibility of partial denitrification and anammox for removing nitrate and ammonia simultaneously in situ through synergetic interactions

In this study, the single-stage partial denitrification-anammox (PD-A) process was started-up in 22 days in a lab-scale up-flow sludge blanket (UASB) reactor to treat wastewater containing NH4+-N and NO3−-N simultaneously. The TN removal rate reached 97.08% with a low effluent TN of 10 mg/L. High-throughput sequencing results revealed the dominant bacterial strains were related to the genus of Thauera and Candidatus Kuenenia. The PD-A system was started-up based on the optimized PD process via inoculated exogenous anammox sludge attributing to the improvement of bacterial adaptation and co-existence by EPS. The PD process was realized in 18 days with the abundance of PD functional bacterium Thauera through fluctuated C/NO-3-N conditions. Moreover, the detrimental effects of starvation on anammox was weaker than that on PD bacteria. The PD-A process was expected to open a new possible perspective in designing NO3−-N and NH4+-N wastewater treatment plants.

Application of down-flow hanging sponge – Upflow sludge blanket system for nitrogen removal in Epinephelus bruneus closed recirculating aquaculture system

A high-rate nitrogen removal process is required to maintain the water quality in aquaculture tanks used to produce high-density fish populations in recirculating aquaculture systems. In this study, a combined pilot-scale system of down-flow hanging sponge (DHS) reactors and upflow sludge blanket (USB) reactors was applied as a nitrogen removal system for a longtooth grouper Epinephelus bruneus recirculating aquaculture system. The DHS reactors demonstrated high total ammonium nitrogen (TAN) removal efficiencies and the TAN concentration in the aquaculture tank was maintained at 0.32 ± 0.12 mg-N·L−1. The USB reactor fed with sodium acetate acted as a denitrification unit and adjusted the pH through denitrification reaction. All E. bruneus survived the entire experimental period and the daily weight gain rate of 0.6%·day−1 was comparable to that in marine aquaculture. This result shows that the DHS-USB system to be a novel applicable system for nitrogen removal processes in recirculating aquaculture systems and further study at a large scale should be recommended.

Exploration of sulfate reducing sludge granulation with real domestic sulfate-laden wastewater

Extending sulfate reducing sludge granulation to real sulfate-laden wastewater was trialed in this study. Two types of reactors, namely sulfate reducing upflow sludge blanket (SRUSB) reactor and continuous stirred tank reactor (CSTR), were used for granulation. Sulfate-reducing granules were observed after 5 months' operation of stepwise hydraulic retention time (HRT) shortening, recirculation cycle adjustment, and air scouring in the SRUSB reactor. Comparatively, granular sludge was achieved in the CSTR after 6 months of cultivation with an average size of 220 μm. With the process of granulation, the HRTs of the two types of reactors were reduced to 2.2 and 2.8 h, respectively for the SRUSB and CSTR reactors. The abundance of sulfate-reducing bacteria (SRB) related genera reached 29.3 and 45% in the SRUSB and CSTR reactors, respectively. Incomplete organic oxidizing SRB were dominant in the CSTR and SRUSB is predominated by complete organic oxidizing SRB, which facilitated a higher organic loading rate. Considering the operating merits, the CSTR is preferable as a pretreatment unit (e.g., for acidification), while the SRUSB reactor can be used for maximum organics removal or sulfide production. Due to the high suspended solids in the influent, full granulation was not achieved by using real sulfate-laden wastewater, and fine particles accumulation in the reactor was also a concern particularly for the long-term operation.

Kinetic study and experimental productions of methane production from UASB reactor treating wastewater from recycled pulp and paper for the continuous test

The aim of this research it is to show how the biogas anaerobic digestion from treatment of recycled pulp and paper wastewater industry (RPPW) can be a renewable energy. Furthermore, a kinetic study of hydrolyzed COD and productions of methane from UASB digester treating RPPW for the continuous test is established. This will allow to reduce the organic matter deposited in landfills and CO2 emissions and to find viable solutions to minimize the environmental impact of RPPW. This study analyses the biogas products and energy recovery processes from a thermic and electric point of view from the theoretical equations. Thus, this study evaluated the performance of mesophilic methanogenic up-flow sludge blanket reactors (UASB) operating continuously in single-stage (UASB I). The maximum methane yields were 250.9 mLCH4/gCOD removed for UASB I, corresponding to 82.7% of the maximum theoretical energy 6.336 kJ/gCOD removed, Methanogenic potential were 4 137 928 m3CH4/year and electrical energy potential were 510 703 MWh/year. The kinetic study allowed us a hydrolysis rate kh = 0.04 indicates a correct simulation for the UASB digester treatment system for RPPW with an R = 99.668%.

Anaerobic degradation of palm oil mill effluent with aluminum bauxite residue for methane production

Experimental study of the anaerobic digestion of palm oil mill effluent (POME) was carried out in an anaerobic upflow sludge blanket reactor (UASBR) with bauxite residue. The production rate of methane 114 L/gCOD/d and CH4 concentration was 205 L gCOD/d at 8.5 g/L of bauxite residue in UASBR. The results showed that the highest methane yield was 37.5 L gCODadded/h; CO2 reduction 1.5 L gCODadded and chemical oxygen demand (COD) removal reached 98.3% at 8.5 g/L of bauxite residue, respectively. The results the best by the modified kinetic model and Umax was 100 mg/L. The kinetic of methane production was also studied. The methane yield coefficient, YM, was 0.69 L CH4/gCODremoved. Anaerobic digestion of acetate was the dominant soluble metabolites in development and specific methanogenic activity results showed that high observed between stoichiometric and experimental higher methane production.

Formation of denitrifying granules in an upflow sludge blanket reactor with municipal sewage and sodium nitrate feeding

Anaerobic/anoxic denitrifying reactors, such as an upflow sludge blanket (USB) reactor, can retain high concentration of biomass inside of the reactor as granular sludge, which allows high nitrogen removal performance from wastewaters. However, granular sludge is critical to high nitrogen removal performance. In this study, simple granulation method was developed in a denitrifying USB reactor fed with municipal sewage and 50 mg-N⋅L−1 of sodium nitrate as an easily available nitrate source, and granular formation, nitrogen removal performance, and microbial community structure were investigated. A 11.4-L USB reactor was operated at an upflow velocity of 50 cm⋅h−1, and hydraulic retention time of 2.9 h under ambient temperature. Granular sludge with up to 3.8 mm of diameter was formed within 15 days, and the nitrate removal rate increased 9.8 mg-N⋅gMLVSS−1 ⋅h−1to 22.5 mg-N⋅ gMLVSS−1 ⋅h−1 at batch exam. 16S rRNA amplicon sequencing indicated that Cloacibacterium sp. was the most abundant in the granular sludge with detection rate of 6.11% to 12.95%. Also, propionate-producing bacterium Paludibacter sp., acetate-utilizing denitrifying bacterium Acidovorax sp. and Dechloromonas sp. were also abundant in the granular sludge. Denitrifying granular sludge was successfully formed in the USB reactor treating real municipal sewage with sodium nitrate feeding.

REVIEW PAPER ON TREATMENT OF INDUSTRIAL AND DOMESTIC WASTEWATERS USING UASB REACTORS INTEGRATED INTO CONSTRUCTED WETLANDS FOR SUSTAINABLE REUSE

The successful use of anaerobic technologies, especially up-flow sludge blanket (UASB) reactors for the treatment of raw domestic sewage and industrial wastewaters in tropical and subtropical countries opened the opportunity to substitute the aerobic processes with anaerobic reactors in removal of organic matter. Proper management of domestic and industrial wastewaters in developing nations is negligible. Even cost effective integrated green technologies like anaerobic reactor with constructed wetland technologies are not applied. Hence the objective of the present review was to assess the pollutant removal efficiency of the up flow anaerobic sludge blanket (UASB) reactor coupled with a constructed wetland (CW) in treating these wastewaters and their capability to produce quality water for sustainable reuse. To achieve the objectives, the review was organized using reputable journals, articles, and review papers. The interpretation of the result of each document was done using tables, bar graphs, Pie chart and lines. The results were reorganized again by calculating average flow rate, hydraulic loading rate, and percentage removal efficiencies. Most research results revealed that use of UASB-CW integrated treatment system is a promising technology in wastewater treatment and able to complying the effluent discharge standards Globally, the following abatement efficiencies ranged from 79.2-93.9%, 89.2-92.9%, 87.2-96.3%, 22.6-96.9%, 33-85.9%, and 97.9-99.99% were achieved for Chemical oxygen demand (COD), Biological oxygen demand (BOD), Total suspended solid (TSS), Total Kjeldhal Nitrogen (TKN), Total phosphorus (TP) and fecal Coliforms (FC), respectively using UASB-CW treatment systems. UASB-CW technologies are effectively integrated treatment systems and can be used for resource scarce developing countries. Since, both treatment technologies are cost-effective, easy operation and maintenance and capable of meeting effluent standards Hence, the indiscriminate disposal of wastewaters and their environmental impacts in Ethiopia can be resolved using these low-cost combined treatment technologies.

REMOCIÓN DE MATERIA ORGÁNICA EN REACTOR ANAEROBIO DE MANTO DE LODOS DE FLUJO ASCENDENTE EN EL TRATAMIENTO DE AGUAS RESIDUALES DEL CAMAL DE HUANCAVELICA

En la presente investigación se evaluó un nuevo sistema de tratamiento primario para aguas residualesindustriales,se utiliza el “Reactor anaerobio de manto de lodos de flujo ascendente” (UASB), aplicado a la remoción de materia orgánica. El sistema a escala piloto fue diseñado para las aguas residuales del Camal Municipal de Huancavelica, el cual se bombeó después del pre tratamiento (cámara de reja gruesa y desarenador) al tanque de almacenamiento de 350 litros para realizar el tratamiento del agua residual en el reactor UASB a escala laboratorio. Se evaluó la eficiencia de remoción de materia orgánica en un reactor UASB, para un tiempo de retención hidráulico (TRH) de 14 horas con un caudal de circulación de 35mL/min se obtuvo una eficiencia mínima de remoción de Demanda Química de Oxígeno (DQO) de 33,66 % y una máxima eficiencia de 76,90 % todo ello en un rango de temperatura de agua residual de 10°C y 19°C. También para este TRH de 14 horas la cantidad de sólidos suspendidos totales disminuyó de 524,34mg/L a 365,04mg/L, obteniéndose una eficiencia de remoción de sólidos suspendidos totales de 30,28%. El tratamiento primario reactor UASB es una alternativa para remover la materia orgánica y sólidos suspendidos totales, aplicado para aguas residuales del Camal Municipal de Huancavelica y en localidades con condiciones de clima y altitud similares; el diseño se optimizó para un TRH de 14 horas para el reactor UASB el cual elevó la eficiencia de remoción de materia orgánica.

Comparison of accelerated anaerobic granulation obtained with a bench-scale rotating bioreactor vs. a stationary container for three different substrates

Anaerobic digestion is a very efficient technology for the treatment of wastewater from the food industries. The upflow sludge blanket reactor (UASB) is used to convert carbon in waste streams to CO2 and CH4. The risk of a shortage of anaerobic granules in a situation that requires a replacement granule charge for the UASB is a barrier to implementation of anaerobic technology in countries without UASB reactors, producing a surplus of granules to provide for an adequate inventory of granules. Accelerated granulation provides a means to reduce this risk. Peach cannery effluent (PCE), sucrose and lactate were tested as possible substrates for accelerated granulation inducement for un-granulated sewage sludge. Six experimental runs of 20 d each were done to explore granule growth. Each substrate was seeded with sewage sludge in a 5.4 l bioreactor rotating at 2 r/min, as well as in a stationary container. A rapid drop in pH occurred during the first few days of every run. A lower overall pH in the bioreactor indicates a higher bacterial activity relative to the stationary container. The big drop in pH initially with PCE and sucrose inhibited methanogenic activity and granule growth for these substrates. The settleability of the final effluent from the reactor is superior to that of the stationary container. The total suspended solids analysis showed that the reactor produced a marked increase in the larger particulate sizes, indicating the positive contribution of the rolling action towards growth of granules.