Startup and operation of anaerobic EGSB reactor treating palm oil mill effluent

A bench-scale expanded granular sludge bed （EGSB） reactor was applied to the treatment of palm oil mill effluent （POME）. The reactor had been operated continuously at 35℃ for 514 d, with organic loading rate （OLR） increased from 1.45 to 17.5 kg COD/（m^3·d）. The results showed that the EGSB reactor had good performance in terms of COD removal on the one hand, high COD removal of 91% was obtained at two days＇ of hydraulic retention time （HRT）, and the highest OLR of 17.5 kg COD/（m^3·d）. On the other hand, only 46% COD in raw POME was transformed into biogas in which the methane content was about 70% （V/V）. A 30-d intermittent experiment indicated that the maximum transformation potential of organic matter in raw POME into methane was 56%. Volatile fatty acid （VFA） accumulation was observed in the later operation stage, and this was settled by supplementing trace metal elements. On the whole, the system exhibited good stability in terms of acidity and alkalinity. Finally, the operational problems inherent in the laboratory scale experiment and the corresponding countermeasures were also discussed.

Removal of phenol by activated carbons prepared from palm oil mill effluent sludge

The study was attempted to produce activated carbons from palm oil mill effluent （POME） sludge. The adsorption capacity of the activated carbons produced was evaluated in aqueous solution of phenol. Two types of activation were followed, namely, thermal activation at 300, 500 and 800%, and physical activation at 150% （boiling treatment）. A control （raw POME sludge） was used to compare the adsorption capacity of the activated carbons produced. The results indicated that the activation temperature of 800℃ showed maximum absorption capacity by the activated carbon （POME 800） in aqueous solution of phenol. Batch adsorption studies showed an equilibrium time of 6 h for the activated carbon of POME 800. It was observed that the adsorption capacity was higher at lower values ofpH （2--3） and higher value of initial concentration of phenol （200--300 mg/L）, The equilibrium data were fitted by the Langmuir and Freundlich adsorption isotherms. The adsorption of phenol onto the activated carbon POME 800 was studied in terms of pseudo-first and second order kinetics to predict the rate constant and equilibrium capacity with the effect of initial phenol concentrations. The rate of adsorption was found to be better correlation for the pseudo-second order kinetics compared to the first order kinetics.

Integration of biological method and membrane technology in treating palm oil mill effluent

Palm oil industry is the most important agro-industry in Malaysia, but its by-product-palm oil mill effluent （POME）, posed a great threat to water environment. In the past decades, several treatment and disposal methods have been proposed and investigated to solve this problem. A two-stage pilot-scale plant was designed and constructed for POME treatment. Anaerobic digestion and aerobic biodegradation constituted the first biological stage, while ultrafiltration （UF） and reverse osmosis （RO） membrane units were combined as the second membrane separation stage. In the anaerobic expanded granular sludge bed （EGSB） reactor, about 43% organic matter in POME was converted into biogas, and COD reduction efficiency reached 93% and 22% in EGSB and the following aerobic reactor, respectively. With the treatment in the first biological stage, suspended solids and oil also decreased to a low degree. All these alleviated the membrane fouling and prolonged the membrane life. In the membrane process unit, almost all the suspended solids were captured by UF membranes, while RO membrane excluded most of the dissolved solids or inorganic salts from RO permeate. After the whole treatment processes, organic matter in POME expressed by BOD and COD was removed almost thoroughly. Suspended solids and color were not detectable in RO permeate any more, and mineral elements only existed in trace amount （except for K and Na）. The high-quality effluent was crystal clear and could be used as the boiler feed water.

High performance electrocoagulation process in treating palm oil mill effluent using high current intensity application

Electrocoagulation process using high current intensity to treat palm oil mill effluent(POME) was investigated in this study.Various operating parameters such as electrolysis time, inter-electrode distance and initial pH were carried out to determine the efficient process condition on the removal of chemical oxygen demand(COD),biological oxygen demand(BOD) and suspended solids(SS).The highest treatment was achieved at 50 min with the removal efficiencies for COD, BOD and SS obtained as 85%, 83%, and 84%, respectively.More than 50 min treatment showed the fluctuated trends of removal efficiencies which can be considered insignificant.The application of higher current resulted in higher removals of organics while the gas bubbles also assisted in removing the pollutant particles by floatation.In an inter-electrode distance study, the removal efficiency decreased when inter-electrode distance was either higher or lower than 10 mm due to the increase of solution resistance and the decrease of anode active surface area.In initial pH study, it was found that high removal efficiencies were achieved in slightly acidic POME sample rather than in neutral or basic condition.An electrocoagulation process by using the optimum operating parameters was able to remove COD, BOD and SS up to 95%, 94% and 96% respectively.The experimental results confirm that application of high current intensity in electrocoagulation provided high treatment efficiency at a reduced reaction time.

A Study on Zeolite Performance in Waste Treating Ponds for Treatment of Palm Oil Mill Effluent

Oil palm currently occupies the largest acreage of farm land in Malaysia. In 2011, the production of palm oil in Malaysia was recorded as 19.8 million tons which has led to a huge amount of wastewater known as palm oil mill effluent (POME). This work focuses on the ponding system which acts as wastewater treatment plant in order to treat POME. The conventional ponding system applied in mills consists of a series of seven ponds. The maintenance costs of the pond are expensive thus study of alternative methods is needed. POME treatment using zeolite shows a potential to overcome the problem. Samples collected from selected ponds are tested and analyzed using water analyzer method. Result from adsorption by zeolite shows a significant reduction of COD, BOD, Fe, Zn, Mn and turbidity. This shows that zeolite is highly potential to be applied as adsorbent in the POME treatment plants. The results here may lead to lower maintenance cost, lower quantity of treatment ponds and lesser land occupied for the treatment of POME in Malaysia.

Efficacy of Purple Non Sulphur Bacterium <i>Rhodobacter sphaeroides</i>Strain UMSFW1 in the Utilization of Palm Oil Mill Effluent

Sustainable use of palm oil mill effluent (POME) has been the major focus in the recent development in palm oil industry due to the fact that environmental issue brought by POME. The purpose of this study was to determine the optimum incubation period of purple non-sulphur bacterium (PNSB) in reduction of chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) in settled POME and to determine the dry cell weight, TN, TP and cell yield of PNSB. Pure isolate of Rhodobacter sphaeroides strain UMSFW1 was cultured in settled POME under anaerobic condition at 2500 lux illumination on light intensity at a temperature of 30°C ± 2°C for 144-h. Parameters such as COD (mg/L), dry cell biomass (g/L), TP (mg/L) and TN (mg/L) in settled POME and bacterial cells were analyzed. A total reduction of TN (43.9%) in settled POME and a total increase of TN (43.2%) in bacterial cell were recorded at the end of experiment. At the same time the reduction of 51.5% chemical oxygen demand was determined from the POME. The highest dry cell weight of 2.44 g/L with cell yield 0.39 (mg/cell/mg COD) was achieved at the end of experiment. A total 24.7% of TP reduction in settled POME was achieved in 144-h culture, but while a maximum 10% of TP in bacterial cell was achieved in 48-h culture. This study shows that PNSB Rhodobacter sphaeroides strain UMSFW1 grows well by using settled POME as substrate and is capable to remove TN in the settled POME and assimilate into bacterial biomass. This study could provide us a further insight in the nutrient removal and COD removal in the bioremediation process by bacterium Rhodobacter sphaeroides strain UMSFW1.

Overview on Application of Response Surface Methodology （RSM） in Treatment of Palm Oil Mill Effluent （POME）

There are many factors affecting the performance of a treatment system especially in the treatment of palm oil mill effluent （POME） as its contains high amounts of suspended solid, low pH, high salt content and high chemical oxygen demand （COD）. However, one factor at a time approach is complicated method in establishing relationship between multiple parameters. Response surface methodology （RSM） is a recommended approach as it is widely used to analyze and study the interactions between multiple parameters and provides optimum output as well as minimizing the defects which result in good treatment system. This paper overviews the recent and current research in the application of RSM in optimizing the treatment development of POME.

Comparison of ASBR and CSTR reactor for hydrogen production from palm oil mill effluent under thermophilic condition

Hydrogen production from palm oil mill effluent (POME) by Thermoanaerobacterium thermosaccharolyticum PSU-2 was investigated both in batch and continuous reactors using anaerobic sequencing batch reactor (ASBR) and continuous stirred tank reactor (CSTR). The hydrogen production determined from batch experiment of POME at an inoculum size of 0%, 10%, 20% and 30% (v/v) was 161, 201, 246 and 296 mL H2/g-COD with COD removal efficiency of 21%, 23%, 23% and 23%, respectively. Continuous hydrogen production was start-up with 30% (v/v) inoculum in both ASBR and CSTR reactors and more than 30% COD removal could be obtained at HRT of 4 days, corresponding to OLR of 11.3 g COD/ L·day. Similar hydrogen production rates of 2.05 and2.16 LH2/L. day were obtained from ASBR and CSTR, respectively. COD removal efficiency of ASBR was 37.7%, while it was 44.8% for CSTR. However, ASBR was stable in term of alkalinity, while the CSTR was stable in term of hydrogen production, soluble metabolites concentration and alkalinity. Therefore, the CSTR was found to be more stable in hydrogen production than ASBR under the same OLR.

Isolation of Bacteria with Purifying Potential and Application in the Treatment of Effluents from an Artisanal Palm Oil Mill in the Littoral Region of Cameroon

It is with the aim of solving the problem of generating large quantities of effluents from palm oil production in the littoral region of Cameroon that this study was carried out with the general objective of reducing the pollutant load of these effluents by using bacteria. To this end, raw palm oil mill wastewater samples were taken for their characterization by evaluating the in-situ (Temperature, pH and (CND) Conductivity) and ex-situ (SS (suspended solid), COD (chemical oxygen demand), BOD (biological oxygen demand) and O/F (oil and fat)) parameters. In addition, bacterial isolation and screening were carried out from samples of contaminated soil based on the production of lipolytic enzymes, the degradation of oils and fats and the reduction of the pollutant load. Results revealed that 28 isolates were able to reduce the pollution parameters of palm oil mill effluents of which D17, D22 and D23 seemed to be the best purifying isolates. The characterization of the POME (palm oil mill effluent), basing the temperature, pH, CND, O/F, SS, BOD and COD showed us values greater than the recommended rate. Partial characterization of these isolates revealed that D17 and D23 are bacteria that could reduce the polluting parameters of the effluents belonged to the Bacillus sp. genus and D22 to the Acinetobacter sp. genus. These results are satisfactory and the bacteria strains obtained could be used in bioremediation.

Aerobic Degradation Process in Palm Oil Mill— Issues, Challenges and Upsurging Its Efficiency through Bioremediation

Palm oil mill effluent (POME) is liquid waste produced from palm oil extraction process. Discharging it to the river without treatment is violation according to Malaysia Environment of Quality Act (EQA) 1974. In Malaysia, ponding system is a conventional treatment method for POME due to its economical and simple process. The treatment process mainly involves two main treatment phases;anaerobic and aerobic degradation. Anaerobic degradation has a proven track record in reducing pollutant properties in POME up to 85%. The real challenge is to increase the efficiency of aerobic process as the biological oxygen demand (BOD) discharge limit has been further reduced from 100 mg·L-1 to less than 20 mg·L-1. One of economical and feasible approach to increase the efficiency of aerobic phase is via bioremediation. This paper describes the limitation of aerobic degradation in ponding system, besides discussed on the important aspects that need to be optimized for a success implementation of bioremediation and its challenges.

Decolorization of molasses melanoidins and palm oil mill effluent phenolic compounds by fermentative lactic acid bacteria

Lactobacillus plantarum SF5.6 is one of the lactic acid bacteria （LAB） that has the highest ability of molasses melanoidin （MM） decolorization among the 2114 strains of LAB. The strains were isolated from spoilage, pickle fruit and vegetable, soil and sludge from the wastewater treatment system by using technical step of enrichment, primary screening and secondary screening. This LAB strain SF5.6 was identified by 16S rDNA analysis and carbohydrate fermentation （API 50 CH）. The top five LAB strains having high MM decolorization （ 55%）, namely TBSF5.8-1, TBSF2.1-1, TBSF2.1, FF4A and SF5.6 were selected to determine the optimal condition. It was found that the temperature at 30°C under facultative conditions in GPY-MM medium （0.5% glucose, 0.1% peptone, 0.1% yeast extract, 0.1% sodium acetate, 0.05% MgSO4 and 0.005% MnCl2 in MM solution at pH 6） giving a high microbial growth and MM decolorization for all five strains. It was noticed that the decolorization of MM by LAB strains might be cell growth associated. L. plantarum SF5.6 grew rapidly within one day while the other strains took 2–3 days. This L. plantarum SF5.6 could rapidly decolorize MM to 60.91% without any lag phase, and it also had the ability to remove 34.00% phenolic compounds and 15.88% color from treated palm oil mill effluent.

Optimization of thermophilic anaerobic-aerobic treatment system for Palm Oil Mill Effluent （POME）

Optimization of an integrated anaerobic-aero- bic bioreactor （IAAB） treatment system for the reduction of organic matter （Chemical Oxygen Demand （COD）, Biochemical Oxygen Demand （BOD） and Total Sus- pended Solids （TSS） concentrations） in Palm Oil Mill Effluent （POME） to legal standards with high methane yield was performed for the first time under thermophilic condition （50~C-55~C） by using response surface meth- odology （RSM）. The experiments were conducted based on a central composite rotatable design （CCRD） with three independent operating variables, organic loading rates in anaerobic compartment （OLRan） and mixed liquor volatile suspended solids （MLVSS） concentration in anaerobic （MLVSSa,） and aerobic compartments （MLVSSa）. The optimum conditions for the POME treatment were determined as OLRan of 15.6 g COD＇L-I＂d-1, MLVSSan of 43100mg.L l, and MLVSSa of 18600mg.L-1, where high aerobic COD, BOD and TSS removal efficiencies of 96.3%, 97.9%, and 98.5% were achieved with treated BOD of 56mg.L1 and TSS of 28mg.LI meeting the discharge standard. This optimization study successfully achieved a reduction of 42% in the BOD concentrations of the final treated effluent at a 48% higher OLRan as compared to the previous works. Besides, thermophilic IAAB system scores better feasibility and higher effectiveness as compared to the optimized mesophilic system. This is due to its higher ability to handle high OLR with higher overall treatment efficiencies （more than 99.6%）, methane yield （0.31 L CH4＂ gl CODremoved） and purity of methane （67.5%）. Hence, these advantages ascertain the applicability ofthermophilic IAAB in the POME treatment or even in other high-strength wastewaters treatment.

Bioremediation strategies of palm oil mill effluent and landfill leachate using microalgae cultivation:An approach contributing towards environmental sustainability

Palm oil mill effluent(POME)is defined as the wastewater that contains high concentrations of organics,nutrients and oil and grease generated from the production process of palm oil.Therefore,proper discharge and management of POME is important to avoid deleterious impact on the environment.In fact,solid waste generation is a precursor for its disposal issues as most of the solid waste generated in developing nations is dumped into landfills.This has led to the threat posed by the generation of landfill leachate(LL).LL is a complex dark coloured liquid consisting of organic matter,inorganic substances,trace elements and xenobiotics.Hence,it is essential to effectively treat the landfill leachate before discharging it to avoid contamination of soil,surface&groundwater bodies.Conventional treatment methods comprises of physical,biological and chemical treatment,however,microalgal-based treatment could also be incorporated.Furthermore,with the benefits offered by microalgae in valorisation,the application of microalgae in POME and leachate treatment as well as biofuel production,is considerably viable.This paper provides an acumen of the microalgae-based treatment of POME and LL,integrated with biofuel production in a systematic and critical manner.The pollutants assimilation from wastewater and CO_(2)biosequestration are discussed for environmental protection.Cultivation systems for wastewater treatment with simultaneous biomass production and its valorisation,are summarised.The study aims to provide insight to industrial stakeholders on economically viable and environmentally sustainable treatment of wastewaters using microalgae,and eventually contributing to the circular bioeconomy and environmental sustainability.

Microwave physicochemical activation:an advanced approach to produce activated biochar for palm oil mill effluent treatment

Empty fruit bunch(EFB)is an industrial waste that is abundantly available in Malaysia.Traditionally,EFBs were burned and dumped on the plantation site,resulting in global warming pollution from methane and carbon dioxide.In this study,the EFB was transformed into a high-surface area of activated biochar through a microwave physicochemical approach involving the combination of steam followed by a hydroxide mixture for palm oil mill effluent(POME)treatment.It was found that BET(Brunauer-Emmett-Teller)surface area and total pore volume of activated biochar were 365.60 m^(2)/g and 0.16 cm^(3)/g,respectively.The surface morphology of activated biochar revealed the formation of well-developed pores that can potentially be used as adsorbents to treat POME.The removal efficiency of biochemical oxygen demand(BOD)and chemical oxygen demand(COD)of POME achieved 75%-55%,respectively.This study offers insight into the transformation of industrial waste into value-added products for sustainable environmental remediation.

可调型组合式水解-接触氧化工艺研究与工程应用

小型工厂生产废水具有水质、水量波动大的特点,普通处理工艺很难适应有水质、水量的大幅度波动。采取可调性组合式水解酸化-接触氧化工艺具有较高的抗冲击负荷和很好的可调节性,应用该工艺可以使处理设施运行稳定,出水达标排放。

操作条件对超滤膜运行经济稳定性能的影响

采用正交实验的方法对棕榈油生产废水二级处理出水的超滤工艺条件进行考察和优化,并用膜通量衰减系数、平均跨膜压差及产水量各自加权相加所得综合指标来表征不同超滤操作条件下膜运行的经济稳定性能。正交试验结果表明,减小膜表面流速和产水率,提高处理废水温度均有利于系统经济稳定地运行;各运行参数对综合指标影响的大小顺序为:膜表面平均流速>产水率>温度;在保证出水质量的前提下,最佳组合操作条件为膜表面平均流速0.7m/s,产水率80%,废水温度30℃。

Biogas Production from POME by Optimum Level of Inputs

The purpose of this research is to optimize biogas production from POME by using anaerobic reactor with various Organic Loading Rate, Carbon-Nitrogen ratio and Hydraulic Retention Time. For conducting this research, a two-stage fermentation anaerobic bioreactor has used at OLR rate1, 2.6, 5, 9 and 11 g/L.d;at C/N ratio 14.54, 20, 28, 36, 41.454;at HRT 2.295, 4, 6.5, 9, 10.70 days. The anaerobic bioreactor is operated for 30 days. The finding of this research demonstrates the optimum input values are OLR is 5 (g/L.d), C/N is 28, HRT is 6.5 days and output of Biogas is 3.8 L/d from POME. This finding will bring benefits to palm oil industries in achieving economic and environmental sustainability. This research concludes that in-depth research into this matter is important to implement this technology in the palm oil industry.