Anaerobic Treatment Process Research Articles

Evaluation of COD and color removals of effluents from UASB reactor treating olive oil mill wastewater by Fenton process

ABSTRACT The study aims to depurate olive oil mill wastewater (OMW) by combining a primary anaerobic treatment and Fenton process. A laboratory scale anaerobic digestion was operated in an up flow anaerobic sludge blanket (UASB) reactor for 30 days under mesophilic (36.5 – 37°C) conditions at organic loading rates (OLR) of 1 kg COD m−3d−1 with HRT of 10 days. During steady-state operation, the anaerobic reactor achieved a 76.8% COD removal. The anaerobic treatment effluent was further treated through the Fenton treatment process using Fe2+ and H2O2. Laboratory scale investigations were performed on the anaerobically treated OMW effluents so as to decide the optimum working conditions (initial pH, dose of Fe2+ and H2O2). Fenton treatment achieved COD and color removals of 91% and 96% at the optimized conditions, respectively. The predicted optimum parameters for the Fenton process were the dosages of 40 mgL−1 Fe2+ and 250 mgL−1 H2O2 demonstrated that optimum operation pH was 3.0 for COD and color removal from the anaerobically treated OMW. In order to remove 1 g of COD from anaerobically treated OMW has been enough 19 mg of Fe2+ and 118 mg of H2O2. Combining anaerobic treatment with secondary Fenton process clearly show that about 98% of COD of 1/8 diluted raw OMW could be successfully treated. The operating costs of the Fenton process optimum condition were also evaluated in this study.

Simulation of two-dimensional attainable regions and its application to model digester structures for maximum stability of anaerobic treatment process

Unlike high-rate anaerobic digesters that employ some mechanism to retain microbial sludge mass, low-rate systems use sufficiently long hydraulic retention times to ensure process stability, which becomes economically unattractive for treating large quantities of waste. This study presents the use of attainable region to develop a new strategy to enhance the stability of low-rate digesters. By considering three digestion cases, diary manure only (batch 1) or diary manure with granular (batch 2) or lagoon (batch) sludge as innoculum, the following findings were obtained. (1) For a given concentration of volatile acids in an anaerobic digester, higher concentrations of methanogenic archae can be attained using a digester structure (combination of different digesters) as opposed to single digester. (2) For a given digested substrate, a change in the source of inoculum results in a change in the limits of achievability by the system (attainable limits for batches 1, 2 and 3 were 46.486(g/L)2, 5.562(g/L)2 and 0.551(g/L)2, which resulted in performance improvements of 118.604%,175.627% and 200.436% respectively), and hence optimal digester structure. The evidence from this study suggests that the technique can be used to simultaneously improve process stability, define performance targets and propose digester structures required to achieve a given target.

A new system design and analysis of a solar bio-digester unit

Mesophilic Anaerobic digestion is, by far, the most used bio-digestion technique worldwide. The coupling of renewable energy sources with such a system is of a great importance for the Challenge of transitioning to the world’s 100% clean energy. The aim of this paper is to introduce a new conception of a solar anaerobic digestion unit treatment production to achieve energy self-sufficiency, by developing a dynamic thermal model for predicting and analyzing the solar anaerobic digestion unit treatment performance, as a function of climatic conditions (ambient temperature, solar irradiation, rain intensity, flow rate effluent, subtract type, ⋯). For this purpose, a modeling simulation for an Up-flow Anaerobic Sludge Blanket (UASB) digester coupled with a new conception and design solar thermal system have been developed and manipulated under TRNSYS platform. The results of the platform developed allowed identifying phenomena leading to major energy consummation from the solar digester unit and technical solutions were recommended to maximize its efficiency and reduce heat losses in an anaerobic digestion treatment process. The present model constitutes a powerful predictive tool for assisting engineers in determining the optimal design of solar heating systems and digesters, as well as in the investigation of the influence of climate-weather type on the reactor heating requirements.The energy analysis results of the solar-UASB digester unit, concludes that the power demand of the current solar digester treatment unit is around 1.2 kW and 3 kW for summer and winter season respectively. Further, the current development platform allows saving 100% of energy consumption for almost ten months per year and 70% for two cold months per year. Also, the results indicated that with the current strategy heating process the solar fraction reaches 85% for all year. The thermal efficiency of the solar collector was computed and found to be about 69% according to the EN12975 standard.The solar treatment unit that can treat a quantity of 65 liters of waste of paper carton recycled per day for 60 liters UASB digester volume. The dynamic thermal analysis of our system shows a fluctuation interval of ±1 °C for winter and an interval of ±0.3 °C for summer which indicates that the mesophilic condition is very respectful and suitable.

Magnetite nanoparticles enhance the bioelectrochemical treatment of municipal sewage by facilitating the syntrophic oxidation of volatile fatty acids

AbstractBACKGROUNDMicrobial electrochemical technologies (METs) represent a novel platform to harvest the energy trapped in municipal wastewater. At the anode of METs, electro‐active bacteria (EAB) anaerobically oxidize wastewater constituents using the electrode as the terminal electron acceptor and, by so doing, generate an electric current. To convert complex wastewater constituents into electricity, EAB must not only establish syntrophic relationships with other members of the microbial community, but also compete with methanogens for consumption of hydrogen and acetate. Here, we examined the addition of magnetite nanoparticles (NPs) (250 mg Fe L−1) as a novel strategy to manipulate such metabolic interactions and in turn maximize the efficiency of wastewater treatment and the yield of electric current generation.RESULTSBatch experiments carried out either in the presence of a mixture of volatile fatty acids or of a synthetic sewage demonstrated that magnetite addition accelerate the rate of electrogenic oxidation of specific compounds, particularly propionate (up to 120%), an intermediate which frequently accumulates during anaerobic treatment processes, while correspondingly enhancing electric current generation (up to 90%), and diminishing the rate of competing methane generation (up to 50%). Notably, the composition of the microbial community was not substantially affected by the presence of magnetite nanoparticles, possibly suggesting that these latter facilitated extracellular electron transfer mechanisms (among microbes and with the electrode), rather than enriching conditions for specific microorganisms.CONCLUSIONThe addition of magnetite NPs may represent a practical strategy to kick‐start a bioelectrochemical system designed for wastewater treatment and improve the effectiveness of electrogenic substrate oxidation processes. © 2019 Society of Chemical Industry

Validated innovative approaches for energy-efficient resource recovery and re-use from municipal wastewater: From anaerobic treatment systems to a biorefinery concept

The development of innovative technologies in wastewater treatment create the concept of biorefinery in wastewater treatment plants (WWTPs), placing anaerobic processes in the highlight. Starting from the conventional anaerobic treatment processes to ‘closing the loop’ scheme, next generation WWTPs are ready to serve for water, energy and materials mining. While bioenergy is still dominating the resource recovery, recovery of value-added materials (i.e. struvite, biopolymers, cellulose) are receiving significant attention in recent years. So, what are the state-of-the-art approaches for energy-efficient resource recovery and re-use from municipal wastewater? This paper follows a critical review on the validated technologies in operational environment available and further suggests possible market routes for the recovered materials in WWTPs. Considering the development and verification of a novel technology together with the valorization of the obtained products, biorefinery and resource recovery approaches were gathered in this review paper from a circular economy point of view. General currently-faced barriers were briefly addressed to pave the way to create to-the-point establishments of resource recovery facilities in the future.

Removal of Organic Pollutants from Tofu-Processing Wastewater through Anaerobic Treatment Process with Short Hydraulic Retention Time

Anaerobic digestion of tofu-processing wastewater was carried out in batch and continuous systems. The performance of continuous system was investigated at HRT of 10 days and OLR of 0.752 kg/m3day. Anaerobic digestion operated in the continuous system generated higher biogas yield (123 mL/g VS) compared with the batch system (43 mL/g VS). The assessment of biodegradation efficiency showed that continuous reactor had higher VS reduction (76%) in comparison to the batch reactor, which only had 57% of VS reduction. Results of the current study also revealed that anaerobic digestion applied for treating the tofu-processing wastewater could recover pH culture from the acidic condition (pH 5) into the level close to the neutral condition (pH 6.6). The current study is highly significant for the development of applied technology for protecting environment. DOI: http://dx.doi.org/10.5755/j01.erem.75.1.21532

Customizing anaerobic digestion-coupled processes for energy-positive and sustainable treatment of municipal wastewater

Anaerobic digestion (AD) technologies offer exciting opportunities for implementation of sustainable wastewater management, which are currently still an energy-intensive and costly process. However, selecting an appropriate AD process is challenging because the treatment performances vary significantly with the technology type, wastewater properties and environmental conditions and a trade-off between the treatment efficiency and other cost and environmental impacts is usually applied. In this study, a multi-criteria evaluation method which gives a balanced consideration between multiple sustainability dimensions and the practical implementation conditions for a specific treatment process was developed for AD-coupled processes evaluation. Six indicators across three metrics (i.e., environmental, economic, and technical performances) were covered in the method. Two representative AD-coupled processes for municipal wastewater treatment and four countries (United States, United Kingdom, China, and India) were selected for the evaluation. A national-specific evaluation shows that the high-rate activated sludge + sludge anaerobic digestion always outperforms the other processes (presently and in the near future) except for India, where up-flow anaerobic sludge blanket + activated sludge process stands out as the currently optimal option based on the 2015 data. Moreover, it is suggested that implementing AD-coupled nutrient recovery technologies will be economically more feasible for the developed countries than the developing ones, because the latter will still prioritize the economically- and environmentally-beneficial technologies in the near future. This work may help identifying key area of improvement needed for municipal wastewater sectors in different countries and provide guidance for national and global policy-makers to promote customized implementation of AD-coupled processes towards energy-positive and sustainable wastewater treatment.

Performance Evaluation of a Thermophilic Anaerobic Membrane Bioreactor for Palm Oil Wastewater Treatment.

Anaerobic treatment processes have achieved popularity in treating palm oil mill effluent due to its high treatability and biogas generation. The use of externally submerged membranes with anaerobic reactors promotes the retention of the biomass in the reactor. This study was conducted in thermophilic conditions with the Polytetrafluoroethylene hollow fiber (PTFE-HF) membrane which was operated at 55 °C. The reactor was operated at Organic Loading Rates (OLR) of 2, 3, 4, 6, 8, and 10 kg Chemical Oxygen Demand (COD)/m3·d to investigate the treatment performance and the membrane operation. The efficiency of the COD removal achieved by the system was between 93–98%. The highest methane yield achieved was 0.56 m3 CH4/kg CODr. The reactor mixed liquor volatile suspended solids (MLVSS) was maintained between 11.1 g/L to 20.9 g/L. A dead-end mode PTFE hollow fiber microfiltration was operated with the constant flux of 3 LMH (L/m2·h) in permeate recirculation mode to separate the clear final effluent and retain the biomass in the reactor. Membrane fouling was one of the limiting factors in the membrane bioreactor application. In this study, organic fouling was observed to be 93% of the total membrane fouling.

The use of agricultural waste for the renewable energy production

In addition to hydroelectric power plants, solar and wind power plants, biogas plants are important in the production of electricity and heat from renewable energy sources. It is known that depending on the type of substrate used for processing and the design features of biogas plants, they have their own advantages and disadvantages. Nevertheless, properly localized biomass installation is able to decrease the use of conventional materials reducing greenhouse gas emissions. Bio-waste, plant residues and other by-products can be used to produce electricity, heat and purified methane as fuel for repaired vehicles. Biogas production is a key technology for the sustainable use of agricultural biomass as a renewable energy source. Both, Poland and Ukraine, have a large agricultural area, and well developed animal cattery, which creates opportunities for alternative energy sources from biomass development.
 Agricultural biogas plant energy produced from waste such manure, slurry and another agricultural waste, is an excellent source of heat, likewise, electricity. Therefore the importance of using agricultural waste as an energy source in the production of biogas shall be emphasized. A significant drawback of the system is the need to provide low economic and environmental losses. For this purpose, the place of biomass harvesting, transport and its preparation together with storage should be taken into account. To achieve the highest efficiency, small biogas plants should have permanent composition of substrate consisting of various ingredients.
 Ukraine and Poland has considerable potential of renewable energy sources development of which can provide significant economic, ecological, and social benefits. The production of biogas has become an attractive source of extra income for many farmers. Biogas production has a useful effect not only on economic, but ecological development, particularly in the rural regions. At the same time, environmental protection aspects have gained additional importance, so that anaerobic treatment processes have become a key technology for environmental and climate protection.
 On the basis of the submitted documentation by the municipal administration and the manufacturer, the operation of biogas plants for the processing of organic agricultural waste in Gorajec and Odrzechowa (Poland) has been presented.

Online prediction of effluent COD in the anaerobic wastewater treatment system based on PCA-LSSVM algorithm.

Since anaerobic wastewater treatment is a nonlinear and complex biochemical process, reasonable monitoring and control are needed to keep it operating stably and efficiently. In this paper, a least-square support-vector machine (LS-SVM) was employed to construct models for the prediction of effluent chemical oxygen demand (COD) in an anaerobic wastewater treatment system. The result revealed that the performance of the steady-state model based on LS-SVM for predicting effluent COD was acceptable, with the maximum relative error (RE) of 11.45%, the mean average percentage error (MAPE) of 0.79% and the root mean square error (RMSE) of 3.08 when training, and the performance fell slightly when testing. Even though, the correlation coefficient value (R) between the predicted value and the actual value of 0.9752 could be achieved, which means this model can predict the variation of effluent COD in general. The dynamic-state models under three kinds of shock loads, which were concentration, hydraulic, and bicarbonate buffer absent, showed good forecasting performance, the correlation coefficient values (R) all excelled 0.99. Among these three shocks, the dynamic LS-SVM model under bicarbonate buffer absent shock achieved the optimal performance and followed by the dynamic-state model under hydraulic shock. This paper provides a meaningful reference to improve the monitoring level of the anaerobic wastewater treatment process.

Dissolved Methane Harvesting Using Omniphobic Membranes for Anaerobically Treated Wastewaters

Dissolved biomethane in anaerobic effluents has long been a hurdle for energy harvesting through anaerobic wastewater treatment processes. Here, we present a novel membrane process for dissolved methane recovery through the normal range of domestic wastewater temperatures by utilizing an omniphobic (nonwetting) microporous membrane. In a process driven by a solubility gradient, dissolved methane is extracted from a methane-rich aqueous solution (feed), transported across the omniphobic membrane, and absorbed into a nonpolar organic solvent (draw) that has a high solubility for methane. We fabricated the omniphobic membrane by coating a microporous polymeric membrane with silica nanoparticles, followed by surface fluorination. Using the omniphobic membrane, we demonstrate that nearly ≥90% of dissolved methane is recovered from methane-saturated feedwater at 15, 25, and 35 °C, simulating anaerobic effluents produced in the psychrophilic to mesophilic temperature range, while negligible transport of water is...

A Novel Model with GA Evolving FWNN for Effluent Quality and Biogas Production Forecast in a Full‐Scale Anaerobic Wastewater Treatment Process

The anaerobic treatment process is a complicated multivariable system that is nonlinear and time varying. Moreover, biogas production rates are an important indicator for reflecting operational performance of the anaerobic treatment system. In this work, a novel model fuzzy wavelet neural network based on the genetic algorithm (GA‐FWNN) that combines the advantages of the genetic algorithm, fuzzy logic, neural network, and wavelet transform was established for prediction of effluent quality and biogas production rates in a full‐scale anaerobic wastewater treatment process. Moreover, the dataset was preprocessed via a self‐adapted fuzzy c‐means clustering before training the network and a hybrid algorithm for acquiring the optimal parameters of the multiscale GA‐FWNN for improving the network precision. The analysis results indicate that the FWNN with the optimal algorithm had a high speed of convergence and good quality of prediction, and the FWNN model was more advantageous than the traditional intelligent coupling models (NN, WNN, and FNN) in prediction accuracy and robustness. The determination coefficients R2 of the FWNN models for predicting both the effluent quality and biogas production rates were over 0.95. The proposed model can be used for analyzing both biogas (methane) production rates and effluent quality over the operational time period, which plays an important role in saving energy and eliminating pollutant discharge in the wastewater treatment system.

Greenhouse gas emission estimation for a UASB reactor in a dairy wastewater treatment plant

Greenhouse gases (GHGs) emissions have been increasing, recently. One of the greenhouse gas emission resources is the anaerobic wastewater treatment process. The up flow anaerobic sludge bed (UASB) reactor is the anaerobic treatment unit located in a dairy wastewater treatment plant (WWTP) in Turkey. Greenhouse gases (GHGs) emission emits from the anaerobic reactor due to the biogas generation. In this study, the on-site greenhouse gas emissions from the anaerobic reactor with and without biogas recovery were estimated from biogas amount and content using a developed model based on IPCC approach. Then, the off-site GHGs emissions were estimated from electricity consumption and chemical use. The biogas recovery reduced the greenhouse gas emissions. The highest reduction of the on-site GHGs emissions was 97%. Chemical use was the major source of the off-site GHGs emissions in this study. The main emission resource was chemical consumption for a UASB reactor located in a dairy WWTP.

Combinations of two-phase anaerobic biological treatment process with for treatment of industrial dye manufacturing wastewater

Combinations of two-phase anaerobic biological treatment process with for treatment of industrial dye manufacturing wastewater

Ferroferric Oxide Significantly Affected Production of Soluble Microbial Products and Extracellular Polymeric Substances in Anaerobic Methanogenesis Reactors.

Conductive materials facilitate direct interspecies electron transfer between acidogens and methanogens during methane (CH4) production. Soluble microbial products (SMP) and extracellular polymeric substances (EPS) produced by microorganisms might act as the electron shuttle between microorganisms and conductive materials. In this study, effects of conductive ferroferric oxide (Fe3O4) on anaerobic treatment process and the production of SMP and EPS were investigated. The maximum CH4 production rate was enhanced by 23.3% with the dosage of Fe3O4. The concentrations of proteins, polysaccharides, and humic substances in tightly bound EPS (T-EPS) were promoted, suggesting that extracellular metabolisms were induced by conductive materials. Distribution of potential electron shuttles such as quinone-like substances, flavins, aromatic amino acids, and dipeptides in SMP and EPS phases were comprehensively investigated and these electron shuttles were significantly affected by Fe3O4. Dipeptides consisting of phenylalanine were widely detected in T-EPS of the Fe3O4 reactor, indicating a potential different extracellular electron exchange pattern with the addition of conductive materials.

Elucidating biochemical transformations of Fe and S in an innovative Fe(II)-dosed anaerobic wastewater treatment process using spectroscopic and phylogenetic analyses

An innovative process consisting of Fe(II)-dosed anaerobic bioreactors and an oxidizing basin was used to continuously treat a synthetic wastewater (COD/sulfate mass ratio 2:1 and Fe/S molar ratio 1:1). Sludge recycling effects were evaluated on ten occasions, in which anaerobic sludge was collected, biochemically oxidized with mechanical aeration in the oxidizing basin before being mixed with the wastewater influent. The sludge recycling resulted in better effluent quality compared to the baseline operation without recycling. More Fe and S were retained as sludge in the bioreactors with sludge recycling (Fe 94%, S 91%) than those when the bioreactors were operated without sludge recycling (Fe 76%, S 86%). Scanning electron microscopic analysis showed that bacterial cells and iron sulfide intermixed in the anaerobic sludge and the presence of microbial exopolymeric substances. X-ray spectroscopic analyses showed amorphous FeS formed from the dosed ferrous iron and biogenic bisulfide, and suggested long-term conversion of the amorphous FeS to more stable crystalline FeS and FeS2 in the anaerobic bioreactors. In the oxidizing basin, oxidation of iron sulfides was of both chemical and biological nature, and their oxidized forms including amorphous FeO/Fe2O3 mixture and partially/fully oxidized sulfurs. Experimental results also indicated amorphous FeS was more readily oxidized than FeS2. Phylogenetic analysis revealed microorganisms related to Desulfomonile tiedjei (sulfur reducing) and Alkaliphilus metalliredigens (iron reducing) in the anaerobic bioreactors, and Thiobacter subterraneus (sulfur oxidizing) and Rubrivivax gelatinosus (iron oxidizing) related microorganisms in the oxidizing basin.

Lifecycle Comparison of Mainstream Anaerobic Baffled Reactor and Conventional Activated Sludge Systems for Domestic Wastewater Treatment.

The objective of this study was to evaluate the lifecycle impacts of anaerobic primary treatment of domestic wastewater using anaerobic baffled reactors (ABRs) coupled with aerobic secondary treatment relative to conventional wastewater and sludge/biosolids treatment systems through the application of wastewater treatment modeling and three lifecycle-based analyses: environmental lifecycle assessment, net energy balance, and lifecycle costing. Data from two pilot-scale ABRs operated under ambient wastewater temperatures were used to model the anaerobic primary treatment process. To address uncertain parameters in the scale-up of pilot-scale anaerobic reactor data, uncertainty analysis and Monte Carlo simulation were employed. This study demonstrates that anaerobic primary treatment of domestic wastewater using ABRs can be incorporated with existing aerobic treatment strategies to reduce aeration demand, reduce sludge production, and increase energy generation. The net result of coupling anaerobic primary treatment with aerobic secondary treatment is a more favorable net energy balance, reduced environmental impacts in most examined categories, and lower lifecycle costs relative to conventional treatment configurations; however, the removal and/or capture of dissolved methane is required to reduce global warming impacts and increase on-site energy generation. With further study, anaerobic primary treatment can be a path forward for energy-positive wastewater treatment.

Evaluation of sulfate-containing sludge stabilization and the alleviation of methanogenesis inhibitation at mesophilic temperature

Methanogenesis process is usually inhibited in the presence of sulfate because sulfate induces the sulfate-reducing bacteria (SRB) to compete with methanogenic bacteria for the same substrate and the produced sulfide has toxicity to the anaerobic microorganisms. Therefore, the possibility for controlling the competition is important for practical application of anaerobic treatment processes of sulfate-containing sludge. In this study, the activated sludge was enriched with sulfate concentration and was treated with various concentrations of nanoscale zero valent iron (nZVI) in order to evaluate the potential of nZVI for alleviating the methanogenesis inhibitation of sulfate-containing activated anaerobic sludge. Generally, due to sulfate anions, the outcomes of this study showed that a rapid accumulation of partially stabilized organic materials was observed which indicates that the whole anaerobic digestion process was ceased. The results also reveal that nZVI contributed to significant increases in methane yield. Meanwhile, SRB in the presence of nZVI can react with sulfate to produce sulfide and subsequently can be precipitated as iron insoluble sulfides due to the sulfate reduction by nZVI. The results demonstrate that nZVI was readily utilized as an electron donor for methanogenic bacteria and sulfate reduction and hence has an assuring potential in waste sludge treatment applications.

Comparison of thermophilic anaerobic and aerobic treatment processes for stabilization of green and food wastes and production of soil amendments

The management of organic wastes is an environmental and social priority. Aerobic digestion (AED) or composting and anaerobic digestion (AD) are two organic waste management practices that produce a value-added final product. Few side-by-side comparisons of both technologies and their digestate products have been performed. The objective of this study was to compare the impact of initial feedstock properties (moisture content and/or C/N ratio) on stabilization rate by AED and AD and soil amendment characteristics of the final products. Green and food wastes were considered as they are two of the main contributors to municipal organic waste. Stabilization rate was assessed by measurement of CH4 and CO2 evolution for AD and AED, respectively. For AD, CH4 yield showed a second-order relationship with the C/N content (P < 0.05); the optimal C/N ratio indicated by the relationship was 25.5. For AED, cumulative CO2 evolution values were significantly affected by the C/N ratio and moisture content of the initial feedstock (P < 0.05). A response surface model showed optimal AED stabilization for a C/N of 25.6 and moisture of 64.9% (wet basis). AD final products presented lower soluble chemical oxygen demand (COD) but lower humification degree and aromaticity than the products from AED. This lower stability may lead to further degradation when amended to soil. The results suggest that composting feedstocks with higher C/N produces an end-product with higher suitability for soil amendment. The instability of end products from AD could be leveraged in pest control techniques that rely on organic matter degradation to produce compounds with pesticidal properties.

Investigation on the Influence of Bio-catalytic Enzyme Produced from Fruit and Vegetable Waste on Palm Oil Mill Effluent

Pre-consumer waste from supermarkets, such as vegetables and fruits dreg are always discarded as solid waste and disposed to landfill. Implementing waste recovery method as a form of waste management strategy will reduce the amount of waste disposed. One of the ways to achieve this goal is through fermentation of the pre-consumer supermarket waste to produce a solution known as garbage enzyme. This study has been conducted to produce and characterize biocatalytic garbage enzyme and to evaluate its influence on palm oil mill effluent as a pre-treatment process before further biological process takes place. Garbage enzyme was produced by three-month long fermentation of a mixture of molasses, pre-consumer supermarket residues, and water in the ratio of 1:3:10. Subsequently, the characterization of enzyme was conducted based on pH, total solids (TS), total suspended solids (TSS), total dissolved solids (TDS), chemical oxygen demand (COD), and enzyme activities. The influence of produced enzyme was evaluated on oil & grease (O&G), TSS and COD of palm oil mill effluent (POME). Different levels of dilution of garbage enzyme to POME samples (5%, 10%, 15%) were explored as pre-treatment (duration of six days) and the results showed that the garbage enzyme contained bio-catalytic enzyme such as amylase, protease, and lipase. The pre-treatment showed removal of 90% of O&G in 15% dilution of garbage enzyme. Meanwhile, reduction of TSS and COD in dilution of 10% garbage enzyme were measured at 50% and 25% respectively. The findings of this study are important to analyse the effectiveness of pre-treatment for further improvement of anaerobic treatment process of POME, especially during hydrolysis stage.