Utilization of renewable durian peels for biosorption of zinc from wastewater

Durian peel is among the renewable biomass wastes abundantly available in Malaysia. An implication of untreated biological materials for biosorption process was intensively reported, that prioritize our work towards sorbent modification. The biosorption potentials of hydrochloric acid (HCl) modified durian peels (HAMDP) for removal of Zn (II) from simulated wastewater was investigated. Characterization of HAMDP was performed by ATR-FTIR, SEM and BET. Spectroscopic studies showed the predominant contributors for Zn (II) biosorption on HAMDP is attributed to hydroxyl, carbonyl, carboxyl and amides groups. Batch adsorption studies revealed optimum conditions of pH 8, 0.5 g biosorbent dose, 4 h contact time and reaction temperature of 313 K. Nonlinear isotherm models suggested applicability of Tempkin and Langmuir models at 313 K. The Langmuir maximum adsorption capacity was 36.73 mg/g. Kinetic studies revealed applicability of pseudo-second-order model. Webber-Morris model indicated possible role of diffusion of Zn (II) within the particles of HAMDP during the sorption process. Freundlich constant and activation energy values confirmed the physical nature of the process. Thermodynamic studies indicated that the process is exothermic and spontaneous. Regeneration studies depicted that HAMDP is economically viable. Conclusively, HCl served two significant purposes, namely; a good modification reagent and best eluent in Zn (II) recovery. Therefore, HAMDP is relatively effective, efficient, economical and most importantly “renewable and sustainable” biosorbent for Zn (II) removal from wastewater

Biosorption and desorption of nickel on oil cake: batch and column studies

Biosorption potential of mustard oil cake (MOC) for Ni(II) from aqueous medium was studied. Spectroscopic studies showed possible involvement of acidic (hydroxyl, carbonyl and carboxyl) groups in biosorption. Optimum biosorption was observed at pH 8. Contact time, reaction temperature, biosorbent dose and adsorbate concentration showed significant influence. Linear and non-linear isotherms comparison suggests applicability of Temkin model at 303 and 313 K and Freundlich model at 323 K. Kinetics studies revealed applicability of Pseudo-second-order model. The process was endothermic and spontaneous. Freundlich constant (n) and activation energy (Ea) values confirm physical nature of the process. The breakthrough and exhaustive capacities for 5 mg/L initial Ni(II) concentration were 0.25 and 4.5 mg/g, while for 10 mg/L initial Ni(II) concentration were 4.5 and 9.5 mg/g, respectively. Batch desorption studies showed maximum Ni(II) recovery in acidic medium. Regeneration studies by batch and column process confirmed reutilization of biomass without appreciable loss in biosorption

Promising potential of electro-coagulation process for effective treatment of biotreated palm oil mill effluents

The critical parameters namely initial pH, time and current density largely impact the process efficiency of electrocoagulation (EC). Few works have been done on observing the interaction of these critical parameters and the possible combined effect on the overall pollutant removal efficiency. Therefore, the knowledge of the combined effect of critical parameter interaction would enhance the optimization of EC parameters to attain maximum efficiency with limited resources. Using aluminium electrodes with interelectrode distance of 10 mm on synthetic wastewater, representing biotreated palm oil mill effluent (BPOME), with a set range of initial pH, current density, and time of 3-8, 40-160 mA/cm2 and 15 to 60 minutes, respectively, the effect of the three critical variables was investigated. The optimum Chemical Oxygen Demand (COD) removal of 71.5% was determined at pH 6, current density of 160 mA/cm2 (with current 1.75 A) at EC time of 15 minutes. The experiment was validated with real BPOME, resulting in the removal efficiency of 60.7 % COD, 99.91 % turbidity, 100 % total suspended solids (TSS) and 95.7 % colour. Removal of a large quantity of pollutants in a time span of 15 minutes with optimized parameters in EC is notable for a wastewater treatment alternative that requires no extensive use of chemicals. The interaction of parameters observed in this study indicated a synergistic contribution of initial pH and current density in removing maximum wastewater COD in 15 minutes of EC

Effects of pH, dosage and contact time on boron removal from synthetic saline water using Moringa oleifera seeds

Boron is one of the key elements required in flora, fauna, as well as human beings. However, human life and eco-systems could be seriously affected when exposed to excessive levels of boron, especially in seawater and groundwater. In this work Moringa oleifera was selected as a precursor adsorbent owing to its eco-friendliness characteristics and favourable removal efficiency of adsorbates. Besides, M. oleifera does not significantly affect the conductivity of water and pH value after the treatment. The main aim of this work was to investigate the potentiality of M. oleifera in the treatment of boron from contaminated saline water. The effect of adsorption parameters such as pH (7 - 9), adsorbent dose of 4000 – 8000 mg/L of solution and contact time of 60 – 180 min was thoroughly investigated. Face-centred Central Composite Design (FCCCD) was applied to optimize these parameters. Consequently, the highest percentage of removal (65%) was achieved at the pH of 8, 120 min of contact time and 6000 mg/L of adsorbent dosage. The adsorption studies stated that the adsorption fitted well with the Freundlich isotherm. Therefore, the outcome of this work revealed that boron could be significantly treated using a prepared adsorbent from M. oleifera. ******************************************************************************** Boron merupakan salah satu elemen yang diperlukan oleh flora, fauna, juga manusia. Walau bagaimanapun, hidup manusia dan ekosistem pasti terkesan apabila di dedahkan secara berlebihan, terutama pada air di lautan dan daratan. Kajian ini menggunakan Moringa oleifera sebagai penjerap kerana ia mempunyai ciri-ciri mesra dan berkesan membuang bahan terjerap dengan berkesan. Selain itu, M. oleifera tidak langsung memberi kesan kepada konduktiviti air dan nilai pH selepas perawatan. Tujuan utama kajian ini adalah mengkaji potensi M. oleifera dalam larutan rawatan air garam boron yang tercemar. Kesan parameter penjerapan seperti pH (7-9), dos penjerapan 4000 – 8000 mg/L larutan dan masa interaksi 60 – 180 minit di kaji dengan teliti. KaedahKomposisi Tumpuan Tengah Muka (FCCCD) digunakan bagi mengoptimumkanparameter-parameter ini. Hasilnya, peratus tertinggi penyingkiran adalah sebanyak (65%)pada pH 8, 120 min masa interaksi dan 6000 mg/L dos penjerapan. Kesimpulannya, kajianpenjerapan ini menyokong kuat teori isoterma Freundlich. Oleh itu, hasil kajian inimenunjukkan boron dapat dirawat dengan menggunakan larutan penjerapan daripada M.oleifera.1

Batch and column studies on biosorption and desorption of nickel on mustard oil cake

Discharge of industrial effluents such as electroplating of Malaysia that contains heavy metals into water bodies could results in deteriorating drinking and ground water quality. The heavy metals are non-biodegradable and show detrimental effect on flora and fauna as well as eco-system. Beyond permissible limit, toxicity of nickel was listed in this thesis. A series of batch and column laboratory studies were conducted in other to investigate the biosorption potentials of mustard oil cake (MOC). This biomass was used for minimization of Ni(II) ions from aqueous medium under different experimental conditions. This research is based on synthetic solution prepared in the laboratory. Parameters such as pH, temperature, contact time, initial nickel concentration, biosorbent dose, particle size of biosorbent and agitation speed indicated a greater influence in the biosorption process. The optimum biosorption was observed at pH 8. The biosorption increases from 0.869 to 0.915 mg/g with increase in temperature from 303 to 323 K at pH 8. Biosorbent dose studies showed increase in biosorption from 59.4 to 78.4% with increase in biosorbent dose from 0.05 to 1 g. The contact time studies revealed an equilibration time between 240 to 720 min. Adsorbate concentration studies showed an increase in biosorption capacity with increase in reaction temperature and concentration. Spectroscopic studies indicated possible involvement of acidic (hydroxyl, carbonyl and carboxyl) groups in biosorption process. Langmuir, Freundlich and Temkin models were applied to the biosorption data. The results fitted Freundlich isotherm model which possessed high correlation coefficient (R2) value compared to other two models. Freundlich constant (n) and activation energy (Ea) values confirmed physical nature of the process. Kinetics studies revealed applicability of Pseudo-second-order model. Thermodynamic parameters indicated that the process is endothermic and spontaneous in nature. The breakthrough and exhaustive capacities for 5 mg/L initial Ni(II) concentration were 0.25 and 4.5 mg/g, while for 10 mg/L initial Ni(II) concentration were 4.5 and 9.5 mg/g, respectively. Batch desorption studies showed 99.4 to 99.8% Ni(II) recovery with HCl solution in single-metal system. Column desorption studies were carried out at 5 and 10 mg/L initial Ni(II) concentration in single metal system. Results showed 82 and 84% of Ni(II) was recovered in initial 10 mL eluent for 5 and 10 mg/L initial Ni(II) concentrations, respectively. Regeneration studies by batch and column process confirmed reutilization of biomass without appreciable loss in biosorption. Finally, mustard oil cake was found to be cost effective and has considerable efficiency of minimizing nickel ion from aqueous solution to permissible limit

Development of durian peel-based adsorbent for zinc and lead ions removal

Toxic waste discharged into water bodies by anthropogenic activities is a worldwide problem. In relative to Malaysia, several reports of surface water contamination are from toxic waste discharged by manufacturing industries. For instance, the Juru and Langat rivers, Johor Straits, the marine environment of Port Klang, etc. were reportedly contaminated by toxic pollutants, including heavy metals. Similarly, discovery of several heavy metals on clam species from 34 different sites on the Malaysian coast revealed severe contamination. Ironically, Pb2+ and Zn2+ were categorically listed among the significant issues of concern in Malaysia. Therefore, the main objective of this research is to treat excess Pb2+ and Zn2+ concentrations from aqueous medium using biosorbent developed from durian waste. The basic concept is that "a waste" was applied to treat "a waste" sufficiently. Also, durian waste was transformed into a value-added biosorbent using physical, chemical, and thermal activations. The two prepared adsorbents were termed as hydrochloric acid-modified durian peel (HAMDP) and durian peel activated carbon (DPAC). Characterization of biosorbents such as particle size, SEM, BET surface area analysis, ATR-FTIR, elemental analysis, and pHPZC was performed. Subsequently, the application of adsorption studies in removing Pb2+ and Zn2+ in static (batch adsorption) and dynamic (fixed-bed column) systems was achieved. The wastewater comprises monocomponent (in a batch process) and bi-component or multi-metal ion (in fixed-bed column) systems. Real wastewater from the textile industry was also treatable using these biosorbents. The results showed that non-modified durian peel (NMDP), HAMDP, and DPAC have an average particle size of 206.7, 110.4, and 5.6 μm, respectively. BET surface area analysis revealed that NMDP, HAMDP, and DPAC have a surface area of 0.6793, 0.8807, and 9.1480 m2/g. Morphologically, the improvement of the biosorbent porosity was testified by SEM. The ATR-FTIR analysis advised the involvement of several functional groups such as hydroxyl, aliphatic, carbonyl, aromatic amines, etc. as an active site on the biosorbents that influence the adsorption mechanisms. The elemental analysis also indicated the fruitfulness of durian peels as a potential precursor for activated carbon production. Batch biosorption study revealed that the influential parameters are pH (optimum: 8.0 for Zn and 7.0 for Pb), temperature (optimum: 40 °C for Zn and 50 °C for Pb), contact time (optimum: 240 min for Zn and 60 min for Pb) with maximum adsorption capacities of 36.7 and 127.83 mg/g for Zn and Pb, respectively. Biosorbent dose of 0.5 g in 100 ml is sufficient in this study. The isotherm studies were then fitted to Langmuir and Freundlich models. Desorption and regeneration studies showed the reusability of the biosorbents. Furthermore, column studies on single and multi-metal ion systems using DPAC indicated the capability of the biosorbent in treating excess Zn and Pb in the real industrial wastewater. The process fitted to Langmuir and linear driving force (LDF) methods. Finally, real wastewater from the textile industry was tested to validate the biosorbents. The worthwhile novelty is the easiest way of an activated carbon production process suggested in this work to achieve acceptable performance of durian peels. Hence, the biosorbent applied in this research can treat heavy metals such as Zn2+ and Pb2+ in Malaysia's real industrial effluent

Elemental and chemical composition of moringa oleifera husk extracts

Moringa oleifera is a well-known tropical plant with myriads medicinal and nutritional benefits. Its nutraceutical functions are due to the presence of mineral element and phytochemical components which necessitate their profiling. In this study, the elemental and chemical profiles of husk wastes from Moringa oleifera plants were elucidated using Liquid Chromatography equipped with an electrospray time-of-flight mass spectrometer (LCMS-QToF) and X-ray Fluorescence analyser. The confirmation of 493 bioactive compounds and two higher concentrations of micronutrients (calcium and potassium) indicated the potential of the Moringa oleifera extracts for medicinal and nutritional purposes. Also, the minimal presence of trace elements such as Cu, Si, Mo and Sr showed that they are non-toxic and can therefore be used as food supplement for both human and in animal feed. The result of this researchcould therefore provide lead for future investigation

Optimization of process parameters for boron adsorption from sea water using Moringa oleifera seeds

Boron is an essential element for plants, animal and human. Nonetheless, its presence in seawater and some natural ground waters could be harmful to plants and animals. Human life and the eco-system could also be seriously affected when exposed to excess boron. Boron has various applications especially in the industrial sector that led to its easy discharge to the environment. In order to safeguard public health, many separation technologies have been used in boron removal from seawater. Among these technologies, adsorption process is highly recommended because it can treat solutions with very low concentration of boron using selective adsorbents. In this work, Moringa oleifera has been chosen to be adsorbent due to its non-toxic and biodegradable properties and promising removal efficiency. Besides, it is environmentally friendly; it does not significantly affect the pH and conductivity of water after the treatment. Therefore, this study aims to investigate the effect of parameters on the adsorption capacity of M. oleifera. The studied parameters that influenced boron sorption are solution pH (7-9), adsorbent dosage (0.4-0.8 g), and contact time (60-180 min) were optimized by using Face-centred Central Composite Design (FCCCD). The results showed that the highest percentage removal of 65% was achieved at optimum pH of 8, contact time of 120 min and adsorbent dosage of 0.6 g. The adsorption studies were better fitted to Freundlich isotherm compared to Langmuir isotherm model

Optimization and activation of renewable durian husk For biosorption of Pb(ii) from wastewater

Biosorption of Lead Pb(II) on durian husk activated carbon (DHAC) was investigated in this study. The effects of operating variables such as pH, biosorbent dose, temperature, initial metal ion concentration and contact time were studied using response surface methodology (RSM). The experimentation was performed in two sets, namely; set 1 and set 2. For experimental set 1, pH was optimized (pH = 7) and the optimum conditions for the remaining parameters were determined as 0.39 DHAC dose, 60 min contact time and 100 mg/L of initial metal ion concentration, yielded maximum biosorption capacity of 14.6 mg/g. Pertaining to experimental set 2, 41.27 °C, 8.95 and 99.96 mg/L were the ascertained optimum conditions for temperature, pH and initial Pb(II) concentration, respectively; which revealed maximum adsorption capacity of 9.67 mg/g. Fourier transform infrared (FTIR) analysis was performed to quantify the major functional groups present on the surface of DHAC that are active in the sorption of Pb(II). The equilibrium adsorption data obeyed Langmuir isotherm and pseudo-second-order kinetic models with maximum Langmuir uptake of 36.1 mg/g. The abundant durian husk could be utilized effectively for removal Pb(II) from polluted water