Post-Treatment Of Palm Oil Mill Effluent Using Modified Sequencing Batch Reactor Augmented With Zeolite

One of the biological treatment system for wastewater treatment is sequencing batch reactor (SBR). Post-treatment of palm oil mill effluent by direct application of municipal wastewater and augmentation of natural zeolite in aerobic modified SBR system. POME contain extremely high concentration of organic pollutants, very low concentration of toxic metallic elements, and low microbial content. Direct application of municipal wastewater as microbial supply and zeolite as natural coagulant in modified aerobic sequencing batch reactor (SBR) conducted in order to decreasing operation time and cost of operation process through the aerobic treatment. Aeration used for mixing and oxygen source in SBR system. Batch study carried out with 5, 10, 15, 20, 25, 30, and 35 g/L zeolite. 15g/L zeolite collected as optimum adsorbent dosage. The size of natural zeolite ranged from 75 μm to 150 μm. Response Surface Methodology (RSM) and Central Composite Design (CCD) were used for collecting the optimum operating conditions (independent variables) which were ratio of municipal wastewater (MWW) to POME, aeration flow and contact time. Seven parameters namely total suspended solids (TSS), biological oxygen demand (BOD5), chemical oxygen demand (COD), ammonia nitrogen (NH3-N), total nitrogen and total phosphorus selected as dependent parameters (responses). Collected results indicates that this single treatment method has capability for effective POME treatment in short time without requiring to sludge acclimatization process. In the optimum condition of municipal wastewater to POME ratio (58.7 v/v; %), aeration rate (6.85 L/min) and contact time (17.9h) for the SBR, efficiency of the reduction for TSS, BOD, COD, colour, ammonia nitrogen, total nitrogen and phosphorus were 99.16%, 90.67%, 98.4%, 84.34%, 98.33%, 96.26% and 93.49% respectively. Mechanism of removal mostly were microbial biodegradation, coagulation, cation exchangeable capacity, and surface adsorbent. Specific effect of municipal wastewater through the microbiological treatment process and assistance influence of zeolite for microbial growth and non-degradable maters coagulation are main aspects of efficiency. Combining municipal wastewater with POME and augmenting with natural zeolite in aerobic modified SBR system, could be considered as a capable microbiological method for POME in cost effective and short time treatment

A comparison of the pyrolysis of olive kernel biomass in fluidised and fixed bed conditions

The use of thermogravimetric analysis to describe biomass kinetics often uses bench top thermogravimetric analyser (TGA) analysers which are only capable of low heating rates. The aim of this research was to compare experimental fast pyrolysis of Olive kernels in a bespoke laboratory thermogravimetric fluidised bed reactor (TGFBR) characterised by rapid heating rates at high flow rates, compared to a smaller bench scale fixed bed TGA system. The pyrolysis in the TGFBR was analysed by using the isothermal kinetic approach and it was theorised that the pyrolysis decomposition reactions occurred by two mechanisms depending on the temperature, resulting in an activation energy of 67.4 kJ/mol at temperatures below 500 °C. For comparison, a bench scale TGA was used to look at the thermal behaviour in different fixed bed thermal conditions giving a higher activation energy of 74.4 kJ/mol due to the effect of external particle gas diffusion. The effect of biomass particle size (0.3–4.0 mm) on the conversion of biomass at different temperatures, was investigated between 300 and 660 °C in the TGFBR. The results suggested inhibition of internal gas diffusion was more important at lower temperatures, but in comparison had no significant effect when measured in the fixed bed TGA at lower heating rates. Bench top TGA analysis of pyrolysis is a rapid and valuable method, but is limited by smaller sample sizes and lower heating rates. In comparison, the conditions encountered with the laboratory scale TGFBR are more likely to be relevant to larger scale systems where heat distribution, heat transfer and mass diffusion effects play major roles in the reactivity of biomass

Co-treatment of landfill leachate and municipal wastewater using the ZELIAC/zeolite constructed wetland system

Constructed wetland (CW) is a low-cost alternative technology to treat wastewater. This study was conducted to co-treat landfill leachate and municipal wastewater by using a CW system. Typha domingensis was transplanted to CW, which contains two substrate layers of adsorbents, namely, ZELIAC and zeolite. Response surface methodology and central composite design have been utilized to analyze experimental data. Contact time (h) and leachate-to-wastewater mixing ratio (%; v/v) were considered as independent variables. Colour, COD, ammonia, nickel, and cadmium contents were used as dependent variables. At optimum contact time (50.2 h) and leachate-to-wastewater mixing ratio (20.0%), removal efficiencies of colour, COD, ammonia, nickel, and cadmium contents were 90.3%, 86.7%, 99.2%, 86.0%, and 87.1%, respectively. The accumulation of Ni and Cd in the roots and shoots of T. domingensis was also monitored. Translocation factor (TF) was >1 in several runs; thus, Typha is classified as a hyper-accumulator plant

Chemical engineering and reactor design of a fluidised bed gasifier

The design, modelling and optimisation of biofuel thermochemical processes are mainly based on the knowledge of reliable chemical kinetics. The determination of reaction kinetics of biomass at high heating rate still highly depends on the extrapolation of results from kinetic data determined at a comparatively low heating rate. To provide more comprehensive kinetic data for gas-solid reactions under isothermal conditions, a thermogravimetric fluidized bed reactor (TGFBR) was designed. Using this novel fluidised bed, gravimetric measurements and high heating rate, the thermal conversion of biomass was investigated. Using a thermogravimetric analyser (TGA) as a fixed bed and the TGFBR as a fluidized bed, the pyrolysis kinetics of olive kernels was studied. The pyrolysis in the TGFBR was analysed using the isothermal kinetic approach and it was theorised that the pyrolysis decomposition reaction occurred by two mechansims. Dependent on the temperature, the resultant activation energy was 67.4 kJ/mole at 500 °C. For comparsion, the TGA gave a higher activation energy of 74.4 kJ/mole due to external particle diffusion. To study the impact of torrefaction on gasification performance, gasification experiments were performed on “as received olive kernels” (AROK) and “as received torrefied olive kernels” (ARTOK) in the TGFBR. The effect of equivalence ratio (ER) (0.15-0.35) and bed temperature (550-750°C) on gasification performance was investigated. Based on thermogravimetric measurements using a mass balance model, the activation energy of AROK was found to be 84 kJ/mole, whereas ARTOK was found to be 106 kJ/mole. The results suggest that diffusion controls the reaction of AROK, while oxidation controls the reaction of torrefied biomass. The pyrolysis of date palm stones was also studied in the TGFBR, and the kinetic expression was determined using a model fitting method. The most probable reaction mechanism for the thermal decomposition of palm stones was three-dimensional diffusion. The activation energy for experiments between 350°C and 600°C for date palm stones was 27.67 kJ/mole. Furthermore, the gasification of date palm stones was investigated at ER (0.15-0.35) and a temperature range of 600-750°C in 50°C increments. Based on the energy yield (7 MJ/kg), the results suggest that the optimum conditions were at T=750°C and ER=0.2. Overall, the result reveals that the TGFBR, in comparison with TGA, would be a viable reactor that enables kinetic analysis of gas-solid reactions under isothermal conditions, benefiting from its features. The parameters obtained from the kinetic study of TGFBR are essential in the scale-up design of useful conversion technologies such as gasification. Also, the pre-treatment of biomass via torrefaction is a promising route to improve gas production in a bubbling fluidised bed gasifier

Kinetics and performance of raw and torrefied biomass in a continuous bubbling fluidized bed gasifier.

This paper is an experimental study of the kinetics of gasification of olive kernel by using a thermogravimetric fluidized bed reactor technique. Gasification of ‘as received’ and torrefied olive kernels were investigated in a lab-scale bubbling fluidized bed gasifier, operating at up to 3.2 kg/hr. The effect of bed temperature between 550°C and 750°C in 50°C increments on the gasification product gas at mass-based equivalence ratios of 0.15 and 0.2 was studied. To explore the potential of torrefied biomass, the gasification results were compared to that of the ‘as received’ biomass. The product gas from torrefied biomass produced higher H2, CO and CH4 concentrations at identical oxidant flow rates in addition to higher cold gas efficiency and higher product gas heating value. The influence of equivalence ratio in gasification was also investigated at reactor temperatures of 750°C and five equivalence ratios (0.15, 0.2, 0.25, 0.3, and 0.35). The results revealed that the torrefied biomass has the highest HHV at an equivalence ratio of 0.2 with a value of 6.09 MJ/Nm3 , while ‘as received’ biomass 4.72 MJ/Nm3 . Kinetic experiments under isothermal conditions were performed for the gasification of the materials in continuous mode. A mass balance model was successfully used to provide the capability of separately determining the rate constant of the reactions taking place. The kinetic parameters were calculated by a first order reaction model giving activation energies for ‘as received’ olive kernels of 84 kJ/mole and for torrefied olive kernels of 106 kJ/mole

Removal of polycyclic aromatic hydrocarbons (PAHs) by different physicochemical methods: A mini-review

PAHs are persistent organic pollutants spread worldwide in our environment, including air, soil, and water. They are a large class of organic pollutants released mainly from anthropogenic sources, including automobiles and incomplete combustion of fossil fuels, power plants, and natural sources like forest fires and volcanic eruptions. In recent years, a variety of treatment methods have been used to degrade PAHs in the environment. This paper reviewed the most frequent physicochemical methods for PAHs removal, including solvent extraction/soil washing, oxidation, ozone, solidification, and supercritical fluid extraction. The findings showed that combining physicochemical methods can be an effective option for better cleanup of PAH from contaminated areas

Education and Ethics of IbnMiskaweh: Presentation and Analysis of His Book ""Ethics Perfection and Ethnic Purification

Having read the book titled "Ethics Perfection and Ethnic Purification" authored by IbnMiskaweh with its contents on education and ethics, I wish to present the contents of this book to benefit from the ideas and opinions of IbnMiskaweh in our current societies. I have written this article emerging from the biography of the author, his scientific status, his books and essays, some of his decencies and advices. Then I talked about the importance of this book and its content, analyzing its texts, showing as much as possible of the educational and ethical principles included therein which we think satisfy our desired goal for highlighting the role of this scholar in the field of education and ethics