Characterization of empty fruit bunch biochar pyrolyzed at different temperatures with respect to activated carbon and their sorption capacities for pentachlorophenol

Pentachlorophenol (PCP) has been used extensively in the wood preservation industry. It is highly persistent in the environment and toxic to living organisms. The present study investigated the effectiveness of an oil palm empty fruit bunch biochar (EFBB) pyrolyzed at 350, 550 and 650°C in adsorbing PCP as compared to a commercial activated carbon (AC). The ash content, surface area and aromaticity increased while the pore volume, cation exchange capacity, O/C and (O+N)/C molar ratios decreased as the pyrolysis temperature increased. Only the EFBB pyrolyzed at 350°C and the AC adsorbed the PCP while no PCP adsorption was observed on the EFBBs pyrolyzed at 550°C and 650°C. The Langmuir maximum adsorption capacity (Qmax) values was 6.035 mg g−1, and 126.582 mg g−1 for the 350°C EFBB and the AC, respectively. The higher porosity and more oxygenated functional groups of the EFBB pyrolyzed at 350°C EFBB could be the reason for its ability to adsorb the PCP compared to the other EFBBs. The high PCP sorption by the AC on the other hand, could be attributed to its high surface area and microporous structure

Adsorption of pentachlorophenol by various modified oil palm empty fruit bunch biochars

The past application of pentachlorophenol (PCP) as a pesticide and wood preservative caused wastewater contamination in Malaysia. The PCP is highly toxic and resistant to biodegradation, hence, adsorption is one of the efficient methods for its remediation. Recently, physical and chemical modifications of biochars have drawn great attention because they can enhance the surface area, porosity and functional groups of the biochars, thus increase the adsorption capacity and provide other environmental benefits. There is no reported study on the application of physically and chemically modified oil palm empty fruit bunch biochar (EFBB) as a sorbent for PCP removal from wastewater. Therefore, the present study determines the effects of different particle sizes (<0.5 mm and <2.0 mm), chemical modifications (HCl, NaOH and FeCl3), solution pHs (3, 5 and 7) and pyrolysis temperatures (350, 550 and 650 oC) on the adsorption capacities of EFBB for PCP. The adsorbents were analyzed for their ash content, Brunauer- Emmett-Teller (BET) surface area, pore volume, iodine number, surface morphology, functional groups, pH, electrical conductivity, cation exchange capacity, CHNSO and their molar ratios, elemental composition, oxygen surface acidic groups and zeta potential. The adsorption of PCP by the adsorbents was conducted using the different concentrations of PCP (0 – 500 mg L-1). The sorption isotherm data were fitted to the Freundlich and Langmuir adsorption isotherms. The first study was carried out to determine the effects of different particle sizes (<0.5 mm and <2.0 mm) of EFBB in adsorbing PCP as compared to activated carbon (AC). The PCP sorption isotherm to the biochars was best described by the Freundlich model with higher sorption rates observed for the <0.5 mm EFBB compared to the <2.0 mm EFBB. However, the commercial AC had the highest adsorption capacity compared to the <0.5 mm and <2.0 mm EFBBs. The second study was initiated to determine the effects of different chemical modifications (HCl, NaOH and FeCl3) of EFBB in adsorbing PCP as compared to the unmodified EFBB and the AC. The adsorption isotherm of PCP by all the adsorbents was better fitted the Freundlich compared to the Langmuir model. Results showed higher adsorption capacity (KF) of the chemically modified EFBBs than the unmodified EFBB. The modified EFBBs also had a higher BET surface area, aromaticity and surface functional groups and these properties increased the adsorption capacities of the modified EFBBs for PCP. However, the commercial AC had the highest KF value among all the modified and unmodified EFBBs. A study was conducted to determine the effects of pHs (3, 5 and 7) on the sorption capacity of the <2.0 mm EFBB. The Freundlich model can fit the sorption data well (R2 > 0.9319) and the adsorption capacity decreased as the solution pH increased from 3 to 7. This is because PCP exists as an anionic species at pH 5 to 7 while it exists as a neutral species at pH 3 to 5, thus reduces the PCP sorption with an increase in the solution pH from 3 to 7. Another study was performed to determine the adsorption of PCP by biochars produced at different temperatures (350, 550 and 650 oC) as compared to the AC. The Freundlich model best fit the PCP adsorption onto the 350 oC EFBB while no PCP adsorption occurs onto the EFBB produced at 550 oC and 650 oC. The 350 oC EFBB showed a high adsorption capacity due to its high porosity and more oxygenated functional groups. However, the AC showed the highest adsorption capacity. The commercial AC had the highest adsorption capacity compared to all the EFBBs due to its highest BET surface area and micropore volume. These findings recommended that the EFBB with small particle size (<0.5 mm), pyrolyzed at a low temperature (350 oC) and activated with NaOH had the potential for alternative adsorbents of PCP removal from wastewater considering the high cost of commercial AC

Effects of empty fruit bunch brochar and urea fertiuzer on the production of Maize and selected tropical soil properties

This study was carried out under rain shelter number 4B located at Faculty of Sustainable Agriculture, Universiti Malaysia Sabah. The objectives of this study were to evaluate the effects of empty fruit bunch (EFB) biochar and urea fertilizer on the growth and yield of maize (Zea mays L.) and selected soil properties. This pot study used a completely randomized design (CRD) as a factorial experiment for duration of about 11 weeks. The two factors were rate of EFB biochar application (0, 7.5 and 15 tha-1) and urea application rates (0, 60 and 120 kg ha-1). Each treatment combination was replicated four times. Plant height, plant total dry matter, fresh cob weight, dry cob weight, soil pH H20, soil pHKO, total soil organic carbon, soil organic matter and soil total nitrogen were measured and all data were analyzed using two way analysis of variance CANOVA) at 5% level of significance. All results are reported on per plant basis. These results showed that there was no Significant interaction between EFB biochar and urea fertilizer on plant height, plant total dry matter, fresh cob weight, dry cob weight and soil total nitrogen. Further, the individual main effects of EFB biochar and urea fertilizer rates had no significant effect on these variables. For 0, 7.5 and 15 tha-1 EFB biochar rates, mean plant height was 111.67 cm, 113.42 cm and 107.50 cm; mean plant total dry matter was 49.40 g, 60.29 g and 45.90 g; mean fresh cob weight was 38.47 g, 25.41 g and 28.93 g; mean dry cob weight was 7.56 g, 6.46 9 and 6.31 9 and mean soil total nitrogen was 0.25%, 0.24% and 0.24% respectively; while for the 0, 60 and 120 kg ha-1 urea rates, mean plant height was 108.92 cm, 108.17 cm and 115.50 cm; mean plant total dry matter was 52.88 g, 51.38 9 and 51.32 g; mean fresh cob weight was 30.09 g, 29.43 9 and 33.28 g; mean dry cob weight was 6.31 g, 6.24 9 and 7.77 g and mean soil total nitrogen was 0.25%, 0.24% and 0.24% respectively. There was a significant interaction between EFB biochar and urea fertilizer on soil pHH20, soil pHKO' total soil organic carbon and soil organic matter. It can be concluded that there is no Significant difference in maize plant growth, yield and soil total nitrogen between EFB biochar application rates. However, its application Significantly improved soil chemical properties such as soil pHH20, soil pHKO, total soil organic carbon and soil organic matter. This interaction between EFB biochar and urea fertilizer needs further investigation

Physicochemical properties of chemically activated empty fruit bunch biochars and their sorption capacities for pentachlorophenol as compared to a commercial activated carbon

Chemical modification has been used to produce biochar composites with enhanced surface properties to adsorb organic contaminants efficiently. In the present study, the effectiveness of an empty fruit bunch biochar (EFBB) activated with hydrochloric acid (A-EFBB), sodium hydroxide (B-EFBB) and iron (III) chloride (Fe-EFBB) in adsorbing pentachlorophenol (PCP) as compared to the non-modified EFBB and a commercial activated carbon (AC) was investigated. The physicochemical properties of all the adsorbents were analysed and compared. The adsorption isotherm of PCP by all the adsorbents were fitted to the Freundlich and Langmuir adsorption isotherms. The maximum PCP adsorption capacity (Qmax) onto the adsorbents followed the ascending order of EFBB < Fe-EFBB < A-EFBB < B-EFBB < AC. These findings indicated that the NaOH activated EFBB had the potential for an alternative adsorbent of PCP removal from wastewater considering the high cost of AC