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The impact of various industrial pollutants on anaerobes and the biodegradation potentials need much emphasis. This study aims to investigate the response of anaerobic microbial systems to cyanuric acid (CA) exposure; CA is toxic and possible carcinogen. First, the long-term exposure of mixed culture bacteria (i.e., municipal sludge) to low-strength wastewater containing 20 mg/L CA was conducted in an up-flow anaerobic staged reactor. Stable performance and sludge granulation were observed, and the microbial community structure showed the progression of genus Acinetobacter known as CA degrader. Second, batch-mode experiment was performed to examine the CA biodegradability at higher doses (up to 250 mg/L of CA) in the absence and presence of glucose as a co-substrate; response surface-based optimization was used to design this experiment and to estimate the optimum CA-glucose combination. CA removal of 77–98% was achieved when CA was co-digested with glucose (250–1,000 mg/L), after 7 days-incubation at temperature of 37 °C, compared to 34% when CA was solely digested. Further, the obtained methane yield dropped when CA exceeded over 125 mg/L, though the deterioration was mitigated by addition of higher concentration of glucose. Overall, we conclude that CA is efficiently degraded under anaerobic conditions when being co-digested with readily assimilable substrate. [ABSTRACT FROM AUTHOR]

Copyright of Revista de la Sociedad Química del Perú is the property of Sociedad Quimica del Peru and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Antibiotics are among the most successful group of pharmaceuticals used for human and veterinary therapy. However, large amounts of antibiotics are released into municipal wastewater due to incomplete metabolism in humans or due to disposal of unused antibiotics. Anaerobic treatment systems increasingly used for removal of antibiotics from wastewater. Today, anaerobic treatment systems commonly used for wastewater containing medium and high degree of organic matters. This study was carried out for the treatment of synthetic wastewater containing different antibiotic group in batch reactor for removal of COD. The treatment process was monitored based on the statistical optimisation data of the batch reactor studies. In the Full factorial tests, 27 different tests are established by considering the variables such as (i) different antibiotic groups (fluconazole, cefamycin and tetracycline); (ii) different initial antibiotic concentrations (25, 50, 75 mg/L) and (iii) a type of co-substrate (propionic acid, glucose, propionic acid-butyric acid-acetic acid mixture). As a result of the statistical study is significant type of antibiotics, antibiotic concentration and type of cosubstrate have a significant effect statistically on the COD removal (p<0.05). The maximum COD removal for the fluconazole (experiment 19) was 98,87%. [ABSTRACT FROM AUTHOR]

In this study, digestate from winery wastes was investigated focusing on phytotoxicity using macrophytes and evaluating the potential contribution of ammonium and copper. Spreading of digestate on soil could represent a suitable approach to recycle nutrients and organic matter, creating an on site circular economy. In this study, digestate quality was evaluated considering both chemical-physical characteristics and biological toxicity applying germination test. The effluent did not meet the entire amendment quality standard defined by Italian law (Decree 75/2010 germination index > 60% with solution of 30% v/v of digestate), but bio-stimulation was observed at low doses (3.15–6.25% v/v) for S. alba and S. saccharatum . The beneficial concentration agreed with Nitrate Directive dose and suggested that limited addition of digestate could have several positive effects on soil characteristics and on crop growth. Specific test using ammonium and copper solutions showed that these pollutants were not directly correlated to observed phytotoxicity. [ABSTRACT FROM AUTHOR]

Inadequate sanitation and poor infrastructure for waterborne sanitation are common in many developing countries. The anaerobic/aerobic baffled reactor (AABR) is a sustainable option for water sanitation in developing countries. In the present study, a 2.50 m³ AABR reactor working with real municipal wastewater was monitored. Four sequenced chambers, the first three being anaerobic and the fourth aerobic composed the AABR reactor. AABR efficiency and performance were examined during four different periods. Organic and hydraulic load increases were adequately absorbed, provoking no instability in the system and demonstrating good configuration for absorbing organic impacts. The AABR had a promising effect on COD removal, which led removal values of total COD up to 74%, and total suspended solid (TSS) removal up to 79%. Regardless of the value on entering, the pH from the reactor effluent remained close to 7 during the four periods, indicating good stability in the reactor. [ABSTRACT FROM AUTHOR]

The effect of graphene oxide on the anaerobic digestion of waste activated sludge was investigated at two graphene oxide concentrations (0.025 and 0.075 g graphene oxide per g volatile solids) using biochemical methane potential tests. The occurrence of 36 pharmaceuticals was monitored in the solid and liquid phases before and after the anaerobic treatment. The addition of graphene oxide improved the removal of most pharmaceuticals detected, even those that are considered persistent to biological degradation, such as azithromycin, carbamazepine, and diclofenac. No significant differences were observed in the final specific methane production without graphene oxide and with the lowest graphene oxide concentration, yet the highest graphene oxide concentration partially inhibited methane production. The relative abundance of antibiotic resistance genes was not affected by the graphene oxide addition. Finally, significant changes in the microbial community including bacteria and archaea were detected with graphene oxide addition. [Display omitted] • 0.075 g graphene oxide/g VSS negatively affects methane production. • The addition of graphene oxide enhances the removal of pharmaceutical compounds. • Graphene oxide addition does not affect the antibiotic resistance genes removal. • Addition of graphene oxide enhanced the proliferation of hydrogenotrophic archaea. [ABSTRACT FROM AUTHOR]

The article reveals issues of reconstruction and upgrading of pumping stations in case of emergency. The main problems to be faced with are lack of capacity, equipment wear and low treatment quality. The article focuses on methods and technologies how to perform reconstruction of pumping stations, which aimed at efficiency rise for the existing pumping stations and reduction of their reconstruction cost. Averaging of inflow in tanks combined with pumping stations is a matter of a significant interest that allows reducing of flow irregularity and furthermore rising of treatment quality on waste water treatment plants. [ABSTRACT FROM AUTHOR]

The article gives a review upon modern ways of waste water treatment that allow producing of biogas. The article highlights that anaerobic methods are of the significant interest to consider aspects of both ecology and economy. The advantages of anaerobic methods to treat industrial waste water of different origin are described. The article also contains a review of possible implementation of biogas technologies for dairy, brewery and chemical plants. Use of biogas treatment for these types of industries. [ABSTRACT FROM AUTHOR]

Passive aeration units are units that operate without the need for electric energy. On the contrary to cascade and spray aerators, tray aerators require a much smaller area for their installation. While researching the design of tray aerators, the authors observed a shortage of literature pertaining to the topic. The research objective is to develop a model for the design of tray aerators for the purpose of increasing the dissolved oxygen in wastewater. The analysis focuses on the jetting free falling flow regime. This paper derives a set of equations that estimate the dissolved oxygen concentration in the effluent from the tray aerator system as a function of the flow rate, number of trays, tray area, spacing between trays, number and diameter of holes per tray. Results illustrate that the aeration performance is largely affected by the tray area, number of trays and flow rate while other parameters did not affect the aeration significantly. [ABSTRACT FROM AUTHOR]

An integrated process composed of of 5 μm cartridge filter, ultrafiltration and nanofiltration membranes has been used for the pre-treatment of cotton dyeing textile wastewater. Treatability of membrane concentrate has been further investigated by means of the anaerobic treatment with and without pre-ozonation. Two identical fermentors have been simultaneously operated to compare the effect of pre-ozonation on removals of organic carbon, total Kjeldalh nitrogen, total phosphorus and sulfate from the concentrate. During the study, average removal efficiencies of COD and SO42- have been determined as 54% and 59% for nonozonated and 45% and 52% for ozonated concentrate, respectively. Results demonstrate that ozonation has a slight positive effect on the biodegradability of membrane concentrate and the removal of possible hazardous pollutants. Low methane content of the produced biogas is attributed to high sulfate concentration in the textile wastewater. Findings of this study indicates that the combination of ozonation and anaerobic treatment can be a suitable alternative for the post-treatment of the concentrate from the membrane treatment of the textile wastewater. [ABSTRACT FROM AUTHOR]

The upflow anaerobic sludge blanket (UASB) reactor and the anaerobic membrane bioreactor (AnMBR) are leading candidates for high-rate anaerobic treatment of domestic wastewater. The objective of this study was to perform a long-term comparison on the treatment of domestic sewage by the UASB and AnMBR systems at pilot scale at ambient temperature conditions and relate this to full-scale performance from a range of domestic strength UASB reactors. Analysis of overall operation indicated that the pilot reactor was more likely to be effective in removing solids (and less effective in soluble COD) than full-scale reactors, but that both had comparable performance ranges (i.e., from very effective, to very ineffective). Analyzing both UASB and AnMBR pilot plants treating the same wastewater, it can be concluded that both systems could achieve comparable performance (the UASB for very short periods), with COD removal efficiencies of more than 90%. However, the UASB could only achieve this performance for weeks at a time with good solids retention and long (>15 h) hydraulic retention time (HRT). This performance in general was not sustainable. For the UASB, the average COD removal at 15-h HRT was approximately 50%, with a significant reduction in performance as the hydraulic loading increased (which effectively reduced the HRT). Conversely, the AnMBR system produced exceptional COD removal at an HRT of 9 h. Considering this, the sustained volumetric methane production (per volume of reactor) was approximately 4 times that in the AnMBR than in the UASB system. • The UASB performance was affected by variation in hydraulic load. • For the UASB, the average COD removal at 15-h HRT was approximately 50 %. • The AnMBR was operated at an HRT of approximately 9 h with stable operation. • The AnMBR produced exceptional COD removal of approximately 85% at an HRT of 9 h. • The main disadvantage of the AnMBR was the energy cost of membrane fouling control. [ABSTRACT FROM AUTHOR]

The effects of anaerobic treatment on the content of polyphenols, antioxidant capability, tocols, and free amino acids (FAAs) in the germinated brown rice (GBR) were investigated. The values of polyphenols and antioxidant capability significantly increased in treated groups, in which the three phenolic acids, i.e. ferulic, p -coumaric, and sinapic acids, showed the most pronounced increase. No significant change was observed in tocols. Among the evaluated FAAs, only the content of aspartic and glutamic acids in the white, red and black GBRs decreased by 75, 65 and 69%, and by 30, 18 and 39% after anaerobic treatment, respectively. While the contents of serine and threonine remained unchanged, all others significantly increased. In particular, the contents of γ-aminobutyric acid (GABA) increased 4.2-, 9.7- and 4.8-folds in the white, red and black GBRs, respectively. The results indicated that additional anaerobic treatment could be used in the production of GBR as a functional food. [ABSTRACT FROM AUTHOR]

To better promote environment friendly development of the coal chemical industry, this study investigated effects of methanol, sodium citrate, and chlorella powder (a type of microalgae) as co-metabolic substances on enhanced anaerobic treatment of coal pyrolysis wastewater with anaerobic sludge. The anaerobic sludge was loaded into four 2 L anaerobic reactors for co-metabolism enhanced anaerobic experiments. Anaerobic reactor 1 (R1) as control group did not add a co-metabolic substance; anaerobic reactor 2 (R2) added methanol; anaerobic reactor 3 (R3) added sodium citrate; and anaerobic reactor 4 (R4) added chlorella powder. In the blank control group, the removal ratios of total phenol (TPh), quinoline, and indole were only 12.07%, 42.15%, and 50.47%, respectively, indicating that 50 mg/L quinoline, 50 mg/L indole, and 600 mg/L TPh produced strong toxicity inhibition function on the anaerobic microorganism in reactor. When the concentration of methanol, sodium citrate, and chlorella was 400 μg/L, the reactors with co-metabolic substances had better treatment effect on TPh. Among them, the strengthening effects of sodium citrate (TPh removal ratio: 44.87%) and chlorella (47.85%) were better than that of methanol (38.72%) and the control group (10.62%). Additionally, the reactors with co-metabolic substances had higher degradation ratios on quinoline, indole, and chemical oxygen demand (COD). The data of extracellular polymeric substances showed that with the co-metabolic substances, anaerobic microorganisms produced more humic acids by degrading phenols and nitrogen-containing heterocyclic compounds (NHCs). Compared with the control group, the reactors added with sodium citrate and chlorella had larger average particle size of sludge. Thus, sodium citrate and chlorella could improve sludge sedimentation performance by increasing the sludge particle size. The bacterial community structures of reactors were explored and the results showed that Aminicenantes genera incertae sedis , Levinea , Geobacter , Smithella , Brachymonas , and Longilinea were the main functional bacteria in reactor added with chlorella. [Display omitted] • Removal ratios of TPh, quinoline, and indole in reactor with chlorella were 47.85%, 81.16%, and 85.12%. • Chlorella improved sedimentation performance by increasing sludge particle size (184.31 μm). • Co-metabolic substances promoted the enrichment of functional bacteria. • Levinea (8.04%), Aminicenantes (7.5%), and Brachymonas (6.31%) were functional bacteria in reactor with chlorella. [ABSTRACT FROM AUTHOR]

This paper investigates the effects of variation in the inoculum to waste ratio on the anaerobic treatment of slaughterhouse waste, and proposes a low cost anaerobic treatment system. The work was carried out using a laboratory scale packed anaerobic digester with a gas collecting chamber. The inoculum used for seeding the reactors was septic tank sludge. The operating temperature ranged from 28 to 37 °C. The experimental results indicated chemical oxygen demand (COD) removal efficiencies ranged from 60 to 90% and increased with increasing inoculum to waste ratio beyond (1:1). The decrease in the temperature (from 37 to 28 °C) reduced the COD removal efficiency from 90 to 75%. The system did not show any sign of destabilization under intermittent mode of operation of the reactors. [ABSTRACT FROM AUTHOR]

Highlights: [•] Palm oil wastewater is treated in suspended closed anaerobic reactor. [•] Significant reduction of chemical oxygen demand was obtained. [•] Accumulated high level of volatile fatty acids could affect methane composition. [•] High methane production rate was obtained from palm oil wastewater. [ABSTRACT FROM AUTHOR]

The anaerobic treatment of sewage has many advantages, such as low energy consumption, sludge reduction, and bioenergy recovery. However, low microbial activity has severely restricted the application of anaerobic treatment of low-strength sewage. In this study, an ultrasound enhancing anaerobic reactor (ABR U) was established and anaerobic sludge was irradiated once a day by ultrasound with the optimal parameter (ultrasonic density of 0.10 W/mL, irradiation time of 10.2 min, and ultrasonic sludge concentration of 10.0–10.5 g/L) obtained by response surface methodology. ABR U and the contrast anaerobic reactor (ABR C) without ultrasound were operated in parallel for anaerobic process. The highest chemical oxygen demand removal rate of ABR U was 93.6%, which was 5.8–11.3% higher than that of ABR C. Compared with ABR C , the dehydrogenase and coenzyme F 420 contents of ABR U increased by 46.6% and 38.2%, respectively, implying that sludge bioactivity was significantly enhanced. The results of extracellular polymeric substances (EPS) demonstrated that the low-intensity ultrasonic irradiation increased the content of EPS by 5.7%, and the protein content increased significantly, which contributed to the increase in organic matter removal. The observation of the morphology of sludge showed that the sludge flocs were dispersed by ultrasonic irradiation, leading to enhanced sludge-sewage mass transfer and a decrease in the dissolved organic matter effluent concentration. Therefore, the aforementioned results indicate that anaerobic treatment of low-strength sewage can be enhanced by low-intensity ultrasound. [Display omitted] • The optimum ultrasonic conditions were 0.10 W/mL, 10.2 min, and 10.0–10.5 g/L. • The content of dehydrogenase and coenzyme F 420 increased by 46.6%, 38.2% respectively. • Ultrasonic irradiation improved the efficiency of ABR for long-term treatment of low-strength sewage. [ABSTRACT FROM AUTHOR]

The effect of limiting biofilm volume using carriers with maximum thickness control on the performance and microbial community composition was investigated in anaerobic moving-bed biofilm reactors (AnMBBRs). Three parallel, continuous AnMBBRs (4 L) were operated (288 d, 24/36 °C) to treat the soluble fraction of a wastewater from a food-manufacturing facility. Two different biofilm carriers controlling maximum biofilm thickness at 200 and 1000 µm (AnoxK™Z-200 and Z-1000) were used in the three reactors, targeting the same projected surface area for biofilm growth (410 m2/reactor): R200 (Z-200), R1000 (Z-1000) and RMix (both Z-200 and Z-1000). The composition of the bacterial (16S rRNA V1-V3) and methanogenic (mcr A gene) communities was analysed using amplicon sequencing. Under relatively constant organic loads (3.6–4.2 gSCOD/Ld, 34–39 gSCOD/m2d, hydraulic retention time=7.7–8 h), R200 presented lower soluble chemical oxygen demand (SCOD) removals (51–60%) than the other reactors (R100 = 91–93%, RMix = 86–91%), likely due to a limited amount of active protected biofilm volume. Lower SCOD removals were associated with higher concentrations of volatile fatty acids in the effluent (R200 =400–800 mgCOD/L; R1000 and RMix<200 mgCOD/L) and lower methane production (R200 =0.66; R1000 =0.72; RMix=0.73 gCH 4 -COD/gSCODremoved). The Z-200 carriers contained a different fermentative/acidogenic bacterial community abundant in representatives of the families Christensenellaceae , Anaerovoracaceae and Synergistaceae, and led to less amount of biofilm biomass growth, albeit more active than that of carriers allowing for thicker biofilms (Z-1000). In contrast, methanogenic populations were less sensitive to biofilm thickness restraint by these carriers. This study shows for the first time that limiting biofilm volume in MBBR carriers can impact the performance and bacterial community in AnMBBR biofilms. [Display omitted] • Limiting biofilm volume in carriers can impact the performance of anaerobic MBBRs. • Lower C removals and biogas production with biofilms thinner than 200 µm. • Carriers that limit thickness below 200 µm seem to contain more active biomass. • Carriers limiting biofilm volume contain distinct bacterial community in AnMBBR. • Methanogenic community composition less sensitive to biofilm thickness restraint. [ABSTRACT FROM AUTHOR]

The degradation of dipyrone (metamizole) was studied for the first time under mesophilic anaerobic conditions using a synthetic wastewater similar to that found in anaerobic digestion (AD) treatment plants. Dipyrone concentration effect (250–25,000 µg L−1) was evaluated in short term batch and long-term semi-continuous operation. After 48 days, biogas production and biodegradability were reduced in the batch AD by 17.7% and 18.8%, respectively, regardless of the dipyrone concentration. However, additions of 1000 µg L−1 to the long-term AD system stimulated biogas production and increased organic matter removal by 68% and 30%, respectively. Although removals of the main metabolite 4-MAA (N-methyl-4-aminoantipyrine) and other transformation products were observed in the batch tests after 48 days, a continuous accumulation of dipyrone by-products in the long-term AD reflected its recalcitrant nature. The occurrence of these metabolites coincided with an increased toxicity of the AD effluent to Aliivibrio fischeri of 79% bioluminescent bacteria-inhibition observed immediately after the addition of the dipyrone, while the germination of Lactuca sativa seeds and growth of Raphidocelis subcaptata were stimulated by the same conditions. The toxicity of by-products was mainly attributed to hydrazinic group according to predictions elaborated by ECOSAR software. The results showed that long term exposure to dipyrone main by-product 4-MAA, as a consequence of build up into environment over continuous discharges of effluents, can significantly affect freshwater organisms. [Display omitted] • Dipyrone additions to long-term Anaerobic Digester stimulated biogas production • Continuous accumulation of dipyrone by-products in the Anaerobic Digester reflected its recalcitrance. • Dipyrone metabolites increased toxicity to Aliivibrio fischeri and stimulated Lactuca sativa/Raphidocelis subcaptata growth. • Hydrazinic group most contributed to the ecotoxicity effects. • Dipyrone by-product 4-MAA can significantly affect freshwater organisms. [ABSTRACT FROM AUTHOR]

Abstract: The reduction of the duration of start-up and the improvement of process control are important factors in order to increase the competitiveness of anaerobic baffled reactor systems. In this paper, the start-up performance of modified anaerobic baffled reactor (MABR) in treating recycled paper mill (RPM) wastewater at batch and continuous phases was investigated. In batch phase, about 3.5L (10d HRT) of RPM wastewater were added daily to the reactor for 9 days, while 7L/day (5d HRT) was pumped into the reactor during the continuous phase. During batch and continuous phase, it was found that methane yield increased significantly from 0.003 to 0.09 L CH4/g COD day. During the whole start-up operation, the system demonstrated a remarkable performance of high COD removal efficiency (up to 71%) on day 30. Nevertheless, the pH was slightly decreased (from 7.3 to 6.2) during the period of phase 1 (batch) and phase 2 (continuous). [Copyright &y& Elsevier]

Copyright of InterfacEHS is the property of Revista InterfacEHS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Listy Cukrovarnicke a Reparske is the property of VUC Praha a.s. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A newly developed natural rubber deproteinization process produces deproteinized natural rubber (DPNR) wastewater as an intermediate product containing a high concentration of sodium dodecyl sulfate (SDS) and rubber. In this study, a novel process to recover the residual rubber and energy as methane from DPNR wastewater was developed. As a pretreatment, SDS and residual rubber in DPNR wastewater were coagulated and recovered by addition of CaCl2 at Ca2+/SDS and Ca2+/rubber mass ratios of 0.070 and 0.055, respectively. The remaining organic matter in the pre-treated DPNR wastewater was converted to methane by using a mesophilic up-flow anaerobic sludge bed (UASB) reactor. The UASB reactor with the diluted pre-treated DPNR wastewater showed a total chemical oxygen demand (COD) removal efficiency of 92 ± 2% at a maximum loading rate of 6.8 ± 1.8 kgCOD-m-3d-1 at a hydraulic retention time (HRT) of 12 h. Under the condition of effluent recirculation with raw pre-treated DPNR wastewater, the UASB reactor showed a total COD removal efficiency of 84 ± 8% at the maximum loading rate of 6.4 ± 1.7 kgCODm-3d-1 at l-IRT of 39 h. The results suggest that the newly developed resource recovery process for DPNR wastewater could be a promising treatment system. [ABSTRACT FROM AUTHOR]

Abstract: Domestic and international researches of solar energy heating for anaerobic wastewater treatment are described in this paper. The design investigation of a solar heating anaerobic sewage treatment system for cold regions is proposed, (I) developing of a solar water heating system for treatment, (II) developing of a high-rate anaerobic reactor for sewage treatment under normal temperature conditions, and (III) solving problems of joint control between the solar water heating system and the anaerobic reactor. This article provides a reference for design and application of the solar energy heating system for anaerobic sewage treatment. [Copyright &y& Elsevier]

Bioremediation is considered as one of the prominent and cost-effective cleanup technology to treat oily sludge disposals. In the present investigation anaerobic bioremediation of petroleum based oily sludge was studied in a slurry reactor by applying different experimental strategies viz., bioaugmentation, biostimulation and co-substrate addition. Total petroleum hydrocarbons (TPH) present in the oily sludge before and after degradation was extracted using soxhlet extraction procedure. The soluble fractions of TPH were eluted using column chromatography. Integrated process documented higher degradation efficiency. The combination of biostimulation, bioaugmentation and co-substrate addition showed efficient degradation of TPH (38.39%), aromatics (50.99%), aliphatics (44.48%), asphaltenes (29.62%) and NSO (nitrogen, sulphur and oxygen) compounds (15.23%). This condition was followed by biostimulation and bioaugmentation (36.89%) and individual operation of bioaugmentation (29.38%). Individual polycyclic aromatic hydrocarbons (PAHs) also showed good degradation pattern where, highest was observed with naphthalene (97.8%) followed by acenaphthylene (92.5%), fluorene (91.2%), anthracene (89.6%), phenanthrene (89.1%), fluoranthene (88.5%), pyrene (88.5%), benzo (A) anthracene (87.9%), chrysene (87.1%), benzo (A) pyrene (70.2%), dibenzo (A, H) anthracene (64.2%), benzo (G, H, I) perylene (49.5%). In all the reactors, degradation of lower ring compounds is significantly noticed compared to the higher ring compounds. [ABSTRACT FROM AUTHOR]

Upflow anaerobic sludge blanket (UASB) reactors have been widely used for treatment of industrial wastewater. In this study, performance of a lab-scale up-flow anaerobic sludge blanket (UASB) reactor, treating a chemical synthesis-based pharmaceutical wastewater, was evaluated under different operating conditions. A (RE) pipe with a diameter of 250 mm and total height of 120 cm and effective height of 100 cm with approximate volume of 49 liter was used as a reactor. The loading rates on reactor were increased in steps to assess the maximum loading capacity of the reactor to study the performance of reactor at different loading rates. The COD concentrations used in the present investigation ranges between 1850 mg/L to 5170 mg/L. The performance of the reactor up to 10.81 kg COD/m³.d was evaluated and the hydraulic retention times were examined. During this study, which lasted for 120 days, the temperature of the wastewater entering the reactor ranged from 30 to 35 °C and no heat exchanger was used. Finally the removal ratio of COD with hydraulic retention time of 33.7 hours and organic loading rate of 10.81 kg COD/m³ day were 54 percent respectively. [ABSTRACT FROM AUTHOR]

Finding solutions to the waste problems generated by human activity represents a high concern of authorities and environment specialists for many years. Furthermore, energy conservation and reduction of the dependency from fossil fuels represents a top priority of governmental organizations at world level. The developments in alcohol industry have resulted in the increase of wastewaters which are highly polluted with organic substances, causing environmental pollution hazards. A wide range of biological and physicochemical treatments have been investigated so far for a safety disposal of alcohol industry effluents. The anaerobic treatment technologies have become increasingly important in recent years due to their low operating costs, effectiveness on reducing the pollution load and production of valuable end products, such as biogas and ecological fertilizers. This paper presents briefly the most important pollution problems caused by high organic loaded wastewaters released in alcohol industry, as well as an overview of the anaerobic treatment technologies developed in the last years to process these effluents efficiently and economically simultaneously with energy recovery. [ABSTRACT FROM AUTHOR]

A lab-scale expanded granular sludge bed (EGSB) reactor was operated at 20°C with low strength wastewater (0.6-0.8 g COD/L) for over 200 days. Reactor was inoculated with mesophilic granular sludge. The up-flow velocity was set to 5 m/h by effluent recirculation. The COD loading was increased up to 12 kg COD/m³/day until the day 76, resulting in hydraulic retention time of 1.5 hours. Physical properties (settleability and diameter) of retained sludge tended to deteriorate during the first 2-3 months, however sludge settleability kept sufficiently in the later part of experiment due to the reconstruction of granular sludge. The growth yield (Yg) of retained sludge (0.13 g VSS/g COD) was about two times higher than mesophilic and thermophilic granular sludge processes while the endogenous decay constant (Kd) is very low (0.0001/day) as compared with those processes. The sludge retention time of retained sludge reduced from 100 days to 40 days by the reduction of hydraulic retention time from 4 hours to 1.5 hours. Maintenance of 40 days of sludge retention time caused the stable retainment of biomass and the significant increase of methanogenic activity of the retained sludge. [ABSTRACT FROM AUTHOR]

In order to establish the appropriate methane fermentation technology for low strength wastewater, a 2.0 L EGSB reactor was operated at 20°C with 0.3 - 0.4 g COD/L of sucrose-based synthetic wastewater for 500 days. At the start up period, the reactor was operated in EGSB mode with a 5 m/h up flow velocity by continuous effluent recirculation. However, the EGSB reactor exhibited insufficient COD removal (50-60%) at COD loading of 7.2 - 9.6 kg COD/m3day due to the low COD concentration in the sludge bed. Therefore, we proposed the new operation mode by switching to UASB mode (without recirculation, 0.7 m/h up flow velocity) for 30 minutes and EGSB mode for 10 minutes in 40 minutes cycle. Moreover we added sodium sulfide to make the low ORP condition. In this operation, COD removal increased dramatically, from 65% to 91%. Additionally, physical properties of the retained sludge were well maintained in this operation mode. Furthermore, the retained sludge possessed appropriate levels of methanogenic activity (0.2-0.4 g COD/g VSS/ day) at 20°C. [ABSTRACT FROM AUTHOR]

The cotton woven fabric has been subjected to anaerobic treatment using a mixed microflora at room temperature followed by mild alkali boiling. The required enzymes are produced in situ by a mixture of microflora and hence does not need external supply of costly enzymes. The treated fabric is then peroxide bleached, dyed with hot brand reactive dye and evaluated for various parameters. The results show that the properties of treated fabric are at par with the conventionally processed ones. The colour values of the treated and dyed samples are in fact higher than the conventionally processed ones. The above process can be easily coupled to the existing hand processing units. The new process may result in considerable reduction in pollution load along with appreciable saving in energy. [ABSTRACT FROM AUTHOR]

This paper presents an overview of 20 years experience of use of UASB (Upflow Anaerobic Sludge Blanket) technology for sewage treatment in India with special focus on YAP (Yamuna Action Plan). So far, more than 20 full-scale UASB sewage treatment plants (STP) treating about 1200 MLD (120,000m3/day) of sewage are in operation at various towns & cities and same numbers are in pipeline in next 4-5 years. Most of the plants have been built under funding from a national scheme of the Central Government of India through its nodal agency National Rivers Conservation Directorate (NRCD) to prevent pollution entering into the major rivers in India. Institutional framework was the key element in the implementation of these plans. Some of the plans like YAP received a soft loan from a foreign agency under which about 16 UASB plants were built. The performances of the UASB STPs in combination with some adequate post-treatment have been found satisfactorily. The performance results of few YAP UASB plants, design criteria of UASB reactors established over the years, construction modifications, operation & maintenance and other emerging issues are also summarized in this paper. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the effect of the ratio between COD and biomass (S0/X0) on inert COD fraction in pharmaceutical wastewaters under aerobic and anaerobic conditions. In this concept, wastewater diluted to 2000 mg.L-1 with the same initial COD and biomass concentration of 50 mg.L-1 were treated in batch reactors to determine the inert COD fraction. The pharmaceutical wastewater consists of a lot of volatile organic compounds, and high concentrations of COD may inhibit particularly the aerobic systems. The aerobic and anaerobic batch runs were operated for 37 days and 86 days, respectively [1]. The results of the aerobic inert COD experiment indicated that the biological removal was only 19%, and 81% of the initial COD level has been removed by air stripping. The anaerobic experiments were carried out at five different S0/X0 ratios and an efficiency of 88 % could be provided. It was seen that increasing S0/X0 ratios did not change the soluble inert COD (S1). Some unexpected peaks, could be observed in raw wastewater, possibly originating from additive effects of particular waste-water fractions increasing COD by degradation or destroyed cell material. Additionally, the concentrations of the volatile fatty acids (VFAs) and their behavior in the inert systems were analyzed and discussed. [ABSTRACT FROM AUTHOR]

The evaluation of environmental performances of solid urban waste management systems is a very important issue to achieve a sustainable development Recycling and reusing a large fraction of waste products yields environmental benefits that can be widely enhanced by adopting energy recovery systems for the remaining waste fraction. Recovering energy from solid urban waste means reducing both fossil fuels consumption and landfill needs. Furthermore, exhaust gases from combustion process can be efficiently cleaned by adopting a modem scrubbing system. Instead, large fraction of the solid exhaust part of the combustion process can be considered quite inert. This implies that the energy recovery process, when possible, is one of the best ways to reduce the environmental impact of waste disposal. In this work, a real case, relative to an Italian city of 100.000 inhabitants, has been examined. Improvements, consisting of electrical power production from the wastes organic fraction anaerobic treatment, to the actual situations have been suggested. An LCA analysis has been performed to evaluate the environmental impact of the actual situation and of the improved one. Environmental benefits, strictly linked to the energy production increase, have been pointed out. [ABSTRACT FROM AUTHOR]

Organic loading rate (OLR) is an important parameter significantly affecting microbial ecology and characteristics of UASB systems. In this study, UASB performance was evaluated in a 1000 1 reactor receiving feed from a traditional medium-size slaughterhouse. The initial seed for granules formed earlier was from a mesophilic municipal anaerobic digester sludge with a VSS content of 29 g l−1. The temperature of influent was adjusted by an inline thermostat around 33 °C. The reactor was started with an OLR of 5 kg SCOD m−3 d−1 with gradual increase to 10 kg SCOD m−3 d−1 over a 2-week period. Examination of VSS data showed that on the average 89.3±11.3% of bioparticle mass was present at the lower 30% of the reactor height. Under steady state conditions, experiments were conducted at OLRs of between 13 and 39 kg SCOD m−3 d−1 and hydraulic retention times (HRT) of 2–7 h. Removal efficiencies in the range of 75–90% were achieved at feed SCOD concentrations of 3000–4500 mg l−1. A reduction in removal efficiency to as low as 67% could have been related to a combined effect of high OLR and low HRT. Up to 300 l of methane were produced per kilogram of SCOD removed at OLR values of less than 30 kg COD m−3 d−1 but methane production rate seemed to decline to below 200 at higher OLR values. No sign of cell washout was observed at high OLRs and sludge loading rates (SLR) of up to 2.7 kg SCOD kg−1 VSS d−1. Elimination capacity of the reactor consistently increased from 9 to 25 kg SCOD m−3 d−1 corresponding to 1–2 kg SCOD kg−1 VSS d−1. Solids retention time (SRT) calculations for the reactor indicated a range of 3.3 days at high upflow velocity of 1 m h−1 to 60.3 days at low upflow velocity of 0.33 m h−1 s during different phases of the study. [Copyright &y& Elsevier]

• CaP granules can replace mined phosphate rock for application as fertilizer. • 35% of PO 4 3− in CaP granules dissolved in citric acid and 85% in H 2 SO 4. • Glowed (550 °C) granules contained 15 wt% of p (35 wt% of P 2 O 5). • Heavy metals and organic micropollutants are below european regulatory limits. Phosphate is essential for food production. However, phosphate rock, which is the main natural source, is becoming worse in quality due to the depletion of the reserves and contamination with heavy metals and radioactive elements. Marketable phosphate contains more than 13 wt% of phosphorus (P), but run-of-the-mine phosphate rock is of lower grade (8 to 11 wt% of P). In this study, calcium phosphate granules (CaP granules) produced during anaerobic treatment of vacuum collected black water (feces and urine, BW) were assessed for their potential as a substitute for phosphate rock. The quality assessment was based on elemental composition (macro nutrients and heavy metals), crystallography and morphology analyses, dissolution tests, and quantification of micropollutants. CaP granules contained 10 wt% of P, from which 35% was dissolved within 5 min in citric acid and 85% in H 2 SO 4. The incineration of the CaP granules increased the P content to 15 wt%, by eliminating the remaining organics (29%), pathogens, and organic micropollutants. Heavy metals (Cu, Zn, Cr, Ni, Cd, As, and Pb) and organic micropollutants in CaP granules were below the Dutch and European regulatory limits for direct fertilizer application. Moreover, incinerated CaP granules complied with the requirements for use in the fertilizer industry. At the current process conditions, CaP granules produced from BW can potentially replace 12% of the phosphate rock used in agriculture as fertilizer. Image, graphical abstract [ABSTRACT FROM AUTHOR]

Highlights • Continuous and anaerobic COD reduction of HTC-wastewater by 58%. • The final continuous and aerobic digestion step led to a total COD reduction of 78%. • Two volumetric loadings, namely 0.44 and 0.88 g COD ·l−1·d−1, yielded 254 and 296 l N·kg oDM −1 of methane. Abstract Wastewater produced by the hydrothermal carbonization (HTC) of various wood and sewage sludge mixtures was subjected to anaerobic and aerobic digestion. Previous studies have analyzed the batch digestion of wastewater with a chemical oxygen demand (COD) of 15 g·l−1, yielding 406 l N biogas per kg of organic dry matter (oDM) with a methane concentration of 77%. The wastewater was continuously digested in a pilot plant with two anaerobic stages followed by one aerobic stage over 500 days, in a continuous stirred-tank reactor (CSTR) with sludge recirculation and an expanded granular sludge bed (EGSB). The aim was to investigate the process's long-term behavior and stability, as well as to determine the maximum possible COD degradation; therefore, the wastewater was treated in its original state via a separate mono-digestion process. Two volumetric loadings, namely 0.44 and 0.88 g COD ·l−1·d−1, yielded 254 and 296 l N ·kg oDM −1 of methane, respectively, as well as 58% and 55% reductions in the COD. The final aerobic digestion step then led to total reductions of 78% and 71%, meaning that the increased volumetric loading caused the final COD to rise from 3.1 to 4.9 g·l−1. Trials attempting to reduce the COD further by ozone treatment, precipitation, and flocculation have been done. [ABSTRACT FROM AUTHOR]

Greenhouse gas emissions in the form of methane and carbon dioxide are produced when municipal and industrial wastewater and their residual solid by-product (sludge) are handled under or subject to anaerobic conditions, thus contributing to the global warming potential or the greenhouse effect. This paper presents estimation methods used for determining methane emissions from the management of wastewater. Applications for estimating countrywide methane gas emissions from wastewater management are presented with the country of Lebanon as an example. The relative significance of these emissions is assessed in comparison with methane emissions from developing and developed countries.Uncertainty associated with the estimation process and mitigation measures to reduce potential impacts of methane emissions from wastewater management are also discussed. [ABSTRACT FROM AUTHOR]

This paper addresses the production of volatile fatty acids with fermentation of whey permeate under acidogenic conditions. The coal-immobilized biomass of an anaerobic fluidized bed reactor operated with afairly constant hydraulic residence time of 12 min transformed the substrate (whey permeate i.e., essentially lactose) into a blend of acetic, propionic, butyric and isobutyric acids corresponding to between 2 and 19, 1 and 6, 11 and 30, 0 and 2% of the initial load (carbon basis), respectively. There was a slight decrease in the sugar transformation efficiency (65 to 48%) with the increase of the organic loading rate (OLR) which varied from 586 to 3339 g sugar/Lreactor.d. At the highest OLR of 3339 g sugar/Lreactor.d, the biomass transformed 19% of the substrate into a blend of acetic, propionic, butyric and isobutyric acids. Residual sugar and biogas were 52 and 2%, respectively, of the initial load (carbon basis). [ABSTRACT FROM AUTHOR]