Upflow Anaerobic Sludge Blanket Technology Research Articles

Sustainable biogas production via anaerobic co-digestion of cheese whey and cattle manure

In Mexico, specifically in Chiapas, the dairy cattle industry plays a significant role in cheese and milk production. However, the large quantities of cattle manure (CM) and cheese whey (CW) generated as byproducts pose environmental challenges if not managed properly. To address this issue, anaerobic digestion (AD) technology offers a sustainable solution by treating organic waste and producing biogas. This research study focuses on assessing the potential of CW and CM, both individually and in co-digestion, in an anaerobic environment. The study also evaluates biogas yield and composition using an up-flow anaerobic sludge blanket (UASB) reactor with different CW and CM mixtures. The findings indicate that the 30CM:70CW ratio exhibited the highest methane yield, surpassing other assays in co-digestion and mono-digestion. Furthermore, the UASB reactor showed that a mixture of 90CW:10CM produced 25.73 L of biogas per gram of volatile solids daily, comprising 60 % methane and 40 % carbon dioxide. This research demonstrates the potential for efficient and environmentally friendly treatment of CM and CW through optimized co-digestion and UASB technology, highlighting the opportunity to generate biogas while reducing waste.

Impact of varying hydraulic retention time for treating distillery effluent in activated sludge system to combat the environmental and health hazards

Ethanol-distilleries are the key supporter to the world's economy, but these are moreover one of the major sources of environmental pollution that can impact the human heath if the effluents are not treated in proper manners. Distillery effluents with high biological oxygen demand (BOD) and chemical oxygen demand (COD) contains toxic chemicals which are reported to be of carcinogenic and mutagenic in nature. One of the widely used technology for the distillery wastewater treatment is based on up-flow anaerobic sludge blanket (UASB) technology along with activated sludge process. This technology has fulfilled a need for high efficiency treatment of wastes from various distilleries. With the increasing demands of distillery units and strict guidelines by government agencies for the environment protection, more efforts are required to achieve the zero liquid discharge (ZLD). The research reported in this paper is an effort to perform the in-situ study for evaluating the impact of varying retention times on the efficiency of the condensate Polishing Unit (CPU) based on UASB technology along with activated sludge process for ZLD. The primary objective was to determine pH, BOD and COD after increasing the HRTs in the aeration tank.

Microbial properties of the granular sludge in a psychrophilic UASB reactor fed with electronics industry wastewater containing organic chemicals

In this study, a lab-scale upflow anaerobic sludge blanket (UASB) reactor was applied to the treatment of artificial electronics industry wastewater containing tetramethylammonium-hydroxide (TMAH), monoethanolamine (MEA), and isopropyl-alcohol (IPA) in order to evaluate process performance and degradation properties. During 800 days of operation, 96% efficiency of chemical oxygen demand (COD) removal was stably achieved at an organic loading rate of 8.5 kgCOD/m3/day at 18–19 °C. MEA degradation, carried out by acid-forming eubacteria, was confirmed within a week. The physical properties of the retained granular sludge were degraded by feeding with TMAH wastewater, but maintained by feeding with MEA wastewater due to an accumulation of species from the genus Methanosaeta and family Geobacteraceae. Analysis of the microbial community structure via SEM and 16S rRNA genes showed a proliferation of Methanomethylovorans-like cells and Methanosaeta-like cells at the surface and in the core of the granular sludge with TMAH, MEA and IPA acclimation. Furthermore, a batch degradation experiment confirmed that process inhibition due to increasing chemical concentration was relatively stronger for TMAH than for MEA or IPA. Thus, controlling the TMAH concentration of the influent to below 1 gCOD/L will be important for the stable treatment of electronics industry wastewater by UASB technology.

Up-Flow Anaerobic Sludge Blanket Reactors in Dye Removal: Mechanisms, Influence Factors, and Performance

Society faces eco-environmental challenges when it comes to managing industrial wastewaters. In particular, textile effluents are one of the main threats to living being due to toxic dyes. Technologies used to remove dye compounds include physicochemical and membrane filtration processes. However, since current technologies have several limitations, including high investment and energy demand, researchers have investigated cheaper and eco-friendly alternatives. Among them, anaerobic processes have been an effective method to decolourise dye-containing effluents. In that direction, the up-flow anaerobic sludge blanket (UASB) technology stands out in terms of high cost-effectiveness. The authors reviewed the published literature on UASB reactors in dye compounds removal. Mechanisms, merits, demerits, and technical aspects of UASB reactors are introduced. Challenges and opportunities are discussed. The major points are 1) mechanisms of dye removal in UASB reactors comprise mainly dye adsorption onto sludge granules and azo bond cleavage (biodegradation), 2) dye structure and concentration, external organic carbon source, redox mediators, and bioreactor operating conditions play a key role in the treatment performance, 3) UASB technology exhibits high decolourisation rates. Removal efficiencies of chemical oxygen demand and colour lie within the range of 60–85% and 75–96%, respectively. However, anaerobic treatments may not be able to mineralise by-products of anaerobic metabolisms. Consequently, post-treatment of the anaerobically treated effluent is required, and 4) the energy production during the decolourisation process in UASB reactors is estimated at 22 kWh per m3 of treated wastewater. Bio-energy recovery can promote wastewater valorisation and decrease the economic burdens of dye-containing effluents treatment. Future studies should focus on optimising influence parameters of full-scale UASB reactors and biogas recovery from dye-containing wastewater treatment.

A REVIEW ON ORGANIC REMOVAL OF MUNICIPAL AND INDUSTRIAL WASTEWATER USING UP-FLOW ANAEROBIC SLUDGE BLANKET (UASB) AND ITS APPLICATION IN ANAMMOX PROCESS

Anaerobic treatment processes are widely recognized as a sustainable wastewater management system for their encouraging results in treating highly concentrated wastewater (bCOD > 4000 mg/L) with low energy requirement, which is more economical than aerobic processes. High rate anaerobic reactors, particularly up-flow anaerobic sludge blanket (UASB) reactors, have been extensively employed worldwide due to their high volumetric organic capacity and less sludge yield. However, some limiting factors need to be resolved for large-scale applications. This review aims to emphasize the organic removal of municipal and industrial wastewater using UASB technology and its application in the anammox process in treating ammonia-rich wastewater.Keywords: Anaerobic, anammox, granulation, Up-flow Anaerobic Sludge Blanket (UASB)

Up-Flow Anaerobic Sludge Blanket (UASB) Technology for Energy Recovery: A Review on State-of-the-Art and Recent Technological Advances.

Up-flow anaerobic sludge blanket (UASB) reactor belongs to high-rate systems, able to perform anaerobic reaction at reduced hydraulic retention time, if compared to traditional digesters. In this review, the most recent advances in UASB reactor applications are critically summarized and discussed, with outline on the most critical aspects for further possible future developments. Beside traditional anaerobic treatment of soluble and biodegradable substrates, research is actually focusing on the treatment of refractory and slowly degradable matrices, thanks to an improved understanding of microbial community composition and reactor hydrodynamics, together with utilization of powerful modeling tools. Innovative approaches include the use of UASB reactor for nitrogen removal, as well as for hydrogen and volatile fatty acid production. Co-digestion of complementary substrates available in the same territory is being extensively studied to increase biogas yield and provide smooth continuous operations in a circular economy perspective. Particular importance is being given to decentralized treatment, able to provide electricity and heat to local users with possible integration with other renewable energies. Proper pre-treatment application increases biogas yield, while a successive post-treatment is needed to meet required effluent standards, also from a toxicological perspective. An increased full-scale application of UASB technology is desirable to achieve circular economy and sustainability scopes, with efficient biogas exploitation, fulfilling renewable energy targets and green-house gases emission reduction, in particular in tropical countries, where limited reactor heating is required.

Novel start-up process for the efficient degradation of high COD wastewater with up-flow anaerobic sludge blanket technology and a modified internal circulation reactor

To avoid wastage of water resources and operating cost increases caused by the traditional start-up process of large amounts of dilution influent chemical oxygen demand (COD), a novel start-up process (NSP) was developed and verified with water hyacinth juice (WHJ) on an up-flow anaerobic sludge blanket (UASB) and modified internal circulation (MIC) reactor. Results show that UASB and MIC reactors were started successfully and that the MIC reactor exhibited a superior performance. The NSP time of the MIC reactor (46 days) was less than that of the UASB reactor (52 days), although the start-up organic loading rate (OLR) of the MIC reactor was higher than that of the UASB reactor. Interestingly, high-throughput sequencing analysis indicated that the reactor configuration significantly impacted the microbial diversity, however, the UASB and MIC reactors had similar predominant methanogens: Methanosaeta and Methanosarcina. Therefore, acetoclastic methanogenesis is the primary pathway of methane formation during WHJ treatment.

Biogas production from recycled paper mill wastewater by UASB digester: Optimal and mesophilic conditions

The anaerobic digestion (AD) has become an alternative source and an attractive treatment method. Up-flow Anaerobic Sludge Blanket (UASB) digester has been designed to treat the Recycled paper mill wastewater (RPMW) in Morocco. This paper provides a research on anaerobic digestion of RPMW using UASB technology. The UASB digester was designed following the characterization of wastewater and the feed rate, with the volume of 70 liters. The UASB reactor treating the RPMW was operated for 130 days with minimal overload problems. The experiments were carried out in the mesophilic temperature (37 °C) at different organic loading rates (OLR). A daily analysis was performed to ensure the efficiency of the digester. In this study, the AD experiment was performed in continuous mode with an effluent inlet flow rate equal to 1 L/h. Using the optimal OLR value 5.18 g COD/Ld and with an effluent 5,7 g COD/L, a biogas yield of 92 N mL/g COD removed (at normal temperature and pressure) was obtained during the RPMW anaerobic treatment. The reactor was operated at an optimal hydraulic retention time (HRT) of 15.14 h with a biogas production volume of the optimal value 62.5 L/d. These results indicate that RPMW can be effectively treated in a UASB reactor with the advantage of producing biogas. We tested our system with RPMW, to see the production capacity of the UASB system, which the objective is to develop the system for the industrial scale.

Environmental impacts and economic benefits of different wastewater management schemes for molasses-based ethanol production: A case study of Thailand

Abstract This research investigates the environmental impacts and economic benefits of six molasses-based ethanol production schemes using open lagoon or upflow anaerobic sludge blanket (UASB) wastewater management system in Thailand (schemes A–F). The aim is to determine the most environmentally and economically favorable scheme in terms of the environmental cost, payback period, and cost savings, using analytic hierarchy process (AHP). Schemes A and B use open lagoon for treating wastewater from ethanol production. The ethanol production of scheme A relies on steam and electricity from a sugar mill on the premises, and scheme B is a stand-alone ethanol plant that purchases steam and electricity from external sources. Schemes C – F use UASB technology. In scheme C, the ethanol plant acquire power from a sugar mill on the premises, and biogas from UASB is used for electricity generation. In scheme D, the stand-alone ethanol plant utilizes both biogas and natural gas in combined heat and power system, while in scheme E, biogas and natural gas are used for steam production while electricity is acquired from external sources. In scheme F, a stand-alone ethanol plant uses biogas for electricity generation and purchases steam. The results indicate that the overall environmental cost of open lagoon is greater than that of UASB. Scheme C has the lowest environmental impacts and environmental cost. The payback period of scheme E is the shortest (2.19 years), and the ethanol production costs after payback period decrease by 3.11, 0.24, and 2.92 Thai baht per liter ethanol under schemes C, E, and F. Scheme C is the most environmentally and economically favorable scheme, given the highest AHP weighted score of 0.354. Since the country's ethanol production is expected to increase to 9 million liters per day by 2021, scheme C should be adopted to make use of molasses and mitigate the environmental impacts.

Innovative upflow anaerobic sludge osmotic membrane bioreactor for wastewater treatment

A novel upflow anaerobic sludge–forward osmotic membrane bioreactor was developed for simultaneous wastewater treatment, membrane fouling reduction, and nutrient recovery. An upflow anaerobic sludge blanket (UASB) reactor was incorporated into the system, suspending the anaerobic sludge at the bottom of the reactor. A forward osmosis membrane replaced the traditional three-phase separator of the UASB technology. The removals of chemical oxygen demand, PO43−, and NH4+ were all more than 95% with low membrane fouling in this system. Halotolerant Fusibacter, which can ferment organics to acetate, was increased rapidly from 0.1% to 5% in this saline environment. Acetoclastic Methanosaeta was the most dominant prokaryotes and responsible for majority of methane production. Reduction of membrane fouling in this system was verified by the fluorescence excitation-emission matrix spectrophotometry. Furthermore, phosphorus recovery and salinity build-up mitigation were achieved using periodic microfiltration to recover 57–105 mg/L phosphorus from pH 9 to 12.

KAJIAN PENDAHULUAN KELAYAKAN PENERAPAN INSTALASI PENGOLAHAN AIR LIMBAH DOMESTIK SECARA KOMUNAL DI PERMUKIMAN KOTA BOGOR

A preliminary assessment of an application of sewerage system with Upflow Anaerobic Sludge Blanket (UASB) and Down flow Hanging Sponge (DHS) technology was conducted inNorth Bogor. The Problem which often emerge in management of domestic wastewater is the limited land area and fund to built and operate a wastewater treatment facility. To overcome such problem, it is needed to develop a cheap wastewater treatment technology with high efficiency, easy to operate and also should be compact. The combination technology of UASB and DHS is proposed as an economic wastewater treatment which easy to handling. Therefore, to make sure that the technology is feasible or not to be built inNorth Bogor, there is need the preliminary assessment. The assessment was conducted through a survey of technical and social economic aspect. The results show that sewerage system using UASB and DHS technology is feasible. Key word: domestic wastewater, upflow anaerobik sludge blanket, downflow hanging sponge, preliminary assessment.

WERF Project ENER5R12: Mainstream Anaerobic Treatment Process Using the UASB Process

The upflow anaerobic sludge blanket (UASB) reactor has been recognized as an important wastewater treatment technology among high-rate anaerobic treatment methods. The objective of this study was to evaluate the performance of a UASB pilot plant treating domestic sewage at ambient temperature conditions and identifying future areas of research to better assess the implementation of this technology to treat low strength sewage. The merits of anaerobic bioreactors are highlighted on the basis of performance, and resource recovery potential. While UASB has the advantage of low capital, operation, and maintenance costs, the performance of the UASB pilot at low residence time is significantly diminished. UASB technology has the ability to achieve high removal efficiencies of COD at a range of temperature conditions. However, its efficiency is directly related to the operating HRT of the system.

Estimation of greenhouse gas emissions from municipal wastewater treatment systems in India

AbstractGreenhouse gas (GHG) emissions generated from municipal wastewater treatment plants in India is estimated in this study. The emissions from the wastewater treatment process as well as from the electricity used during the treatment process are estimated by using the methodology of Intergovernmental Panel on Climate Change. The present treatment plants of capacity 15 997 million litres per day (MLD) contributes towards GHG emissions of 7.3 Mt of CO2‐eq/year. The future GHG emissions would depend upon the treatment technology used for treating 34 109 MLD of untreated wastewater. The highest GHG emissions would occur if all new wastewater treatment plants are based on upflow anaerobic sludge blanket technology, 19.66 Mt CO2‐eq/year and lowest if sequential batch reactor technology is adopted, 2.93 MtCO2‐eq/year.

Effect of influent COD/SO42− ratios on biodegradation behaviors of starch wastewater in an upflow anaerobic sludge blanket (UASB) reactor

A lab-scale upflow anaerobic sludge blanket (UASB) has been run for 250days to investigate the influence of influent COD/SO42− ratios on the biodegradation behavior of starch wastewater and process performance. Stepwise decreasing COD/SO42− ratio enhanced sulfidogenesis, complicating starch degradation routes and improving process stability. The reactor exhibited satisfactory performance at a wide COD/SO42− range ⩾2, attaining stable biogas production of 1.15–1.17LL−1d−1 with efficient simultaneous removal of total COD (73.5–80.3%) and sulfate (82.6±6.4%). Adding sulfate favored sulfidogenesis process and diversified microbial community, invoking hydrolysis–acidification of starch and propionate degradation and subsequent acetoclastic methanogenesis; whereas excessively enhanced sulfidogenesis (COD/SO42− ratios <2) would suppress methanogenesis through electrons competition and sulfide inhibition, deteriorating methane conversion. This research in-depth elucidated the role of sulfidogenesis in bioenergy recovery and sulfate removal, advancing the applications of UASB technology in water industry from basic science.

Market dynamics as a driver towards the evolution of research needs: the case of up-flow anaerobic sludge blanket seeding granules

Market dynamics offer positive (incentive) or negative (disincentive) feedback loops that shape the research needs for, or certain aspects of, a particular technology. Our case study results illustrate how market dynamics have influenced the evolution of research needs in the wastewater treatment sector, with specific emphasis on research on the seeding granules used to start up-flow anaerobic sludge blanket (UASB) reactors. Because of insufficient data on the actual market demand for seeding granules for UASB plants, surrogate data, on the number of UASB plants installed internationally from 1970 to 2007, were used to predict the potential future demand for seeding granules. Secondly, we also determined whether or not such a demand would provide sufficient economic justification for the installation of one or more plants for manufacturing seeding granules in South Africa. The direct relationship between the demand for seeding granules and increased numbers of UASB plants was based on the premise that the start-up of each plant required a seeding inoculum before effluent could be treated. Three methods were used to obtain the data used in this study, namely: a literature survey, a questionnaire survey, and interviews with people having expert knowledge of wastewater treatment technologies. Our findings suggest that the UASB technology has largely been marginalised in the wastewater treatment market because of the introduction of competing technologies, and due to high initial capital costs. As a result, South African market demand for the seeding granules is likely to be very small or non-existent, because the number of new UASB plants installed per year is likely to decrease in future. Secondly, our research suggests that market dynamics, political contexts and technologies will continue to change, exerting an increasing downward influence on the UASB technology over time.Keywords: market dynamics, UASB, EGSB, seeding granules, market demand, inoculum

A Comparative Study of Sewerage Treatment Plants With Different Technologies In The Vicinity Of Chandigarh City

Chandigarh city has a well planned underground network of pipes for the disposal of sewerage generated in the city. The sewerage system of the city has been designed by taking into account the natural slope of the city, which is from north to south. Chandigarh city hosts three Sewerage Treatment Plants (STP's) namely: STP Diggian located at sector 66 of S.A.S Nagar, Punjab Territory, Mohali, based upon MBBR (Moving Bed Biofilm Reactor) technology which is at a distance of about 4km from the nearest planned sector 47, STP Raipur Kalan located at a distance of 6km from Chandigarh adjoining to railway station based upon UASB (Upflow Anaerobic Sludge Blanket) technology and STP Raipur Khurd, based upon ASP (Activated Sludge Process) technology located on Chandigarh-Ambala highway at a distance of approximately 8 km from Interstate Bus Terminal sector 17, 1 km from Airport and 3 km from Railway Station. These plants are designed and constructed with an aim to manage waste water so as to minimize or remove organic matter, solids and other pollutants before it enters a water body. In the present study various Physico-Chemical and Biological Parameters are evaluated and are compared with the Central Pollution Control Board (CPCB) General Standards for the Discharge of Environmental Pollutants Part-A : Effluents, into Inland Surface Water according to The Environment (Protection) Rules, 1986 Schedule-VI because the Effluent from these STP's enters river Ghaggar. Also the performance of each STP was evaluated in terms of Removal/Reduction Efficiency. Since out of 30 MGD of STP, Mohali 10 MGD treated waste water is reused for Irrigation purpose in various gardens and lawns of Sector : 19, 20, 21, 29, 30, 33, 34, 36, 40, 42, 43, 44, 46, 47, 48, 51 and 52 of Chandigarh city therefore Average Effluent of this STP is compared with the CPCB Effluent Discharge Standards into Land for Irrigation. It was observed according to the results obtained that BOD value of the Effluent of STP Raipur Kalan and Raipur Khurd was not under permissible limit during the duration of study and Average Phosphate value of Raipur Khurd was exactly upto permissible limit according to Central Pollution Control Board (CPCB) General Standards for the Discharge of Environmental Pollutants Part -A: Effluents, into Inland Surface Water according to The Environment (Protection) Rules, 1986 Schedule-VI. According to the results obtained it was also revealed that all the Physico-Chemical and Biological Parameters evaluated for STP Mohali was under permissible limit according to CPCB Effluent Discharge Standards into Land for Irrigation and also into Inland Surface water. Also it was revealed from the performance study that efficiency of the three STP's mentioned above was poor with respect to removal of TDS (Total Dissolved Solids) in contrast to the removal /reduction efficiency in other parameters like TSS (Total Suspended Solids), BOD (Biochemical Oxygen Demand) and COD (Chemical Oxygen Demand). The order of reduction efficiency was 1.TDS(39%) 2.COD(56%) 3.TSS(76%) 4.BOD(79%), 1.TDS(46%) 2.TSS(51%) 3.BOD(73%) 4.COD(78%) and 1.TDS(55%) 2.COD(75%) 3.TSS(78%) 4.BOD(88%) respectively in Raipur Kalan STP, Raipur Khurd STP and Diggian Mohali STP. In comparison with each other, out of the three STP's, Diggian STP Located at Mohali showed better results for the effluent, its reduction efficiency for BOD is 88% and is highest among Raipur Kalan STP and Raipur Khurd STP which is 79% and 73% respectively. From the evaluation it is further revealed that Mohali STP based upon MBBR technology have more stable results than Raipur Kalan STP, based upon UASB technology and Raipur Khurd STP, based upon ASP technology. The order of overall performance for the technologies studied in different STP's are: 1.MBBR 2.UASB 3.ASP which proves that MBBR technology is ahead to UASB and ASP technology in the treatment of sewage. Additionally, the working principle, problems associated with the operation and maintenance of all the three STP's is also discussed.

Flax Retting Wastewater Part 1: Anaerobic Treatment by Using UASB Reactor

The performance of UASB (Up-flow Anaerobic Sludge Blanket) reactor was investigated in the present study for treatment of flax retting wastewater. Batch and continuous experiments on a pilot scale were designed. The initial seed for granules (bacteria acclimation) formed earlier was from municipal sewage treatment plant with VSS of 18 - 20 g/L. Batch experiments proved that the sludge retention time (SRT) was 77 days. Under steady state conditions, continuous experiments were conducted at organic loading rates (OLRs) in the range of 1.2 to8.6 kgCODs m–3·d–1, where the hy- draulic retention time (HRT) decreased from 72 to 12 hrs. The results proved that the UASB technology provides good COD removal efficiency from 64.5% to 90.5% as COD loading rate decreased and good biogas production at proper food: micro-organism (F:M) ratios.

Textile Dye Removal in Single-Phase and Two-Phase Anaerobic Biotreatment Systems

This research compares performances of an anaerobic two-phase reactor system and a conventional single-phase reactor system in treatment of a synthetic dye wastewater. The two-phase reactor setup used four anaerobic reactors based on upflow anaerobic sludge blanket technology as acid reactors and an expanded granular sludge bed (EGSB) reactor as a methane reactor. An anaerobic reactor based on EGSB technology constituted the single-phase reactor setup. The reactors were operated at different hydraulic retention times (HRTs). The acid reactors removed up to 67% of the influent chemical-oxygen demand (COD) and 77% of the influent dye or color. An average of 10–25% acidification was achieved, and acetic acid, propionic acid, and butyric acid were the major volatile fatty acids produced in the acid reactors. The organic loading or the influent dye concentration did not have any significant effect on acid production or its speciation. The two-phase system could be operated at a HRT as low as 7.5 h with at leas...

SELECTED EXPERIENCES IN THE APPLICATION OF UASB TECHNOLOGY FOR LARGE-SCALE MUNICIPAL ADVANCED WASTEWATER TREATMENT APPLICATIONS

SELECTED EXPERIENCES IN THE APPLICATION OF UASB TECHNOLOGY FOR LARGE-SCALE MUNICIPAL ADVANCED WASTEWATER TREATMENT APPLICATIONSAs many countries embark in the costly task of implementing or upgrading wastewater treatment, the issue of considering “appropriate” technologies becomes very relevant. Typically, this consideration is heavily influenced by the construction and the operational and maintenance (O&M) costs of the facility. Upflow Anaerobic Sludge Blanket (UASB) technology is increasingly being...Author(s)Julián SandinoFrank RogallaJaime LondoñoRicardo SadirBanu SumnerJaro KolarikAbigail FieldSourceProceedings of the Water Environment FederationSubjectSession 61: Anaerobic Treatment for Municipal Wastewaters: An Emerging Technology in Latin AmericaDocument typeConference PaperPublisherWater Environment FederationPrint publication date Jan, 2004ISSN1938-6478SICI1938-6478(20040101)2004:10L.23;1-DOI10.2175/193864704784131617Volume / Issue2004 / 10Content sourceWEFTECFirst / last page(s)23 - 33Copyright2004Word count287

Combining UASB technology and constructed wetland for domestic wastewater reclamation and reuse

The enhancement of water quality by constructed wetland systems is increasingly being employed throughout the world. For this study two treatment schemes consisting of an Up-flow Anaerobic Sludge Blanket (UASB) reactor followed by either subsurface flow (SSF) or free surface flow (FSF) constructed wetlands have been investigated. The common macrophyte in Egypt Typha latifolia (cattail) was used at a planting density of three rhizomes/m2. To evaluate the role of plants in the treatment process, an unplanted gravel bed identical to the SSF unit was operated as control. During the study period, the wetlands were fed with the UASB effluent at an organic loading rate ranging from 17.3 to 46.8 kg BOD5/ha·d (55.1 to 134.6 kgCOD/ha·d). Effectiveness of the system for the removal of key constituents (COD, BOD, TSS, nutrients and FC) has been investigated. The results showed that, the level of CODtot, and TSS in the final effluent of SSF was lower than that of FWS. Subsurface flow wetland has demonstrated higher overall efficiency than the unplanted control. FC reduction reached 4 log units. Further studies are on-going to optimize the wetland design under local environmental conditions.