Effect Of Acid Treated Biochar On Urea Fertilizer For Retaining Ammonium And Nitrate Ions In Soil

Urea is widely used as fertilizer because it is inexpensive, economical to produce, soluble in water and contain high amount of nitrogen (47%). Biochar impregnated urea has the potential to improve nitrogen use efficiency of plant by reducing the N losses via gaseous emission of ammonia (NH3) and nitrous oxide (N_2O) to the atmosphere and nitrate leaching into surface and ground water bodies. The aim of this study is to investigate the biochar performance in reducing the loses of ammonium and nitrate ions by increasing its negative surface charge to improve its cation exchange capacity (CEC) which may influence its ability to retain the ions. The biochar was derived from rubber wood sawdust, underwent a pyrolysis process before treated with phosphoric acid at various concentration to improve its ion retention properties. From the optimization result obtained using response surface method regarding the acid treatment process, the best setting suggested for biochar was treatment with 1.5M phosphoric acid at 90°C. Confirmation runs obtained from the best setting were 7.06 pH with negative surface charge of 7.18 mmol/gram. Ammonium and nitrate retention in soil were measured and compared between ureas impregnated with acid treated and untreated biochars. Results showed that urea with acid treated biochar was able to retain 48.7% of ammonium and 45.2% of nitrate as compared to 44.7% and 28.0% shown by urea with untreated biochar, after week 3. This study affirms that acid treated biochar increases the ability of urea to retain more ammonium and nitrate compared to the untreated biochar

Characterization Of Phosphoric Acid Biochar Derived From Rubber Wood Sawdust For Enhancement Of Urea Fertilizer Impregnation

This paper examines the physiochemical properties of phosphoric acid treated biochar for improvement of urea fertilizer impregnation process. The biochar was heated with phosphoric acid (H3PO4) of 1.5 M (TB1) and 1 M (TB2) concentrations at 80 and 90°C temperature respectively. The treated biochar then were impregnated with 2 wt. % of dissolved urea fertilizer while continuously stirred until the mixture recrystallize to form solid urea impregnated biochar fertilizer (TB1-U and TB2-U). TB1 revealed highest composition of C (66.36%), H (6.53%) and N (1.65%) compared to TB2 composition of C (61.84%), H (4.60%) and N (1.06%). FT-IR results indicated the presence of C-O stretch functional group at 1200 cm−1 to 900cm−1 wavelength and the presence of aromatic ring (C=O) stretching vibration at 1590cm−1-1550cm-1 wavelength revealed chemical reaction occurred due to phosphoric acid treatment. The microporosity results display more micropores formation on the sample surfaces, thus provide higher surface area possible for urea molecule to be impregnated. SEM-EDX exposed qualitatively and quantitatively the presence of 43% N on TB1-U surfaces compared with slightly lower at 42wt% of N on TB2-U surface evidenced the effectiveness of phosphoric acid treatment on enhancement of the biochar specific surface area to be impregnated with urea for nutrient retained

Optimization Of Phosphoric Acid Treatment Biochar Using Response Surface Method

Biochar is derived from the crop residue as a multifunctional materials for agricultural applications and as a soil enhancer to improve soil fertility. The physical and chemical properties of biochar are improved via phosphoric acid treatment. The aim of this study is to optimize the acid treatment of biochar for two factor; 1) concentration of phosphoric acid and 2) heating temperature via Response Surface Methodology (RSM) by using Design Expert 10 software. A set of 11 experiments were carried out based on Central Composite Design (CCD) with three repetitions at center point. Hence, the responses were set in two factors; 1) pH and 2) negative surface charge. The biochar produced from slow pyrolysis process of rubber wood sawdust (RWSD) in a horizontal tube furnace heated at 5⁰C/minute from room temperature to maximum temperature of 400⁰C with holding time of 1 hour. Characterization of treated biochar was performed using Scanning Electron Microscopy (SEM) and SEM with EDX. Analysis of variance of the pH and negative surface charge indicated that the selected quartic model was significant with p-value of <0.05. Predicted parameters to obtain the maximum negative surface charge were 1 Mol of acid concentration and 85⁰C of heating temperature with desirability of 98%

Microstructural Analysis On Biochar Obtained From Rubber Wood Sawdust Via Slow Pyrolysis

Biochar was derived from the crop residue as multifunction materials for agriculture purposes and a soil amendment to improve soil fertility. Rubber wood sawdust (RWSD) was heated slowly inside the vertical furnace for an hour at temperatures ranging from 300 °C to 700 °C. The aim of this study is to investigate the influence of pyrolysis temperatures on the physiochemical properties of the biochar. The properties of biochar were characterized using X-ray diffraction (XRD) and scanning electron microscope (SEM) attached with Energy Dispersive X-ray for elemental analysis. It was found that pore size distribution was more uniform on samples heated at higher temperature (700 °C). The SEM-EDX analysis confirmed the O:C ratio was directly proportional to the heating temperature. These means that slow pyrolysis of RWSD at 700 °C could produce biochar of greater cation exchange capacity (CEC) that important for soil fertility improvement