Abdulrasoul Al-Omran

Pyrolysis temperature induced changes in characteristics and chemical composition of biochar produced from conocarpus wastes

Conocarpus wastes were pyrolyzed at different temperatures (200–800 °C) to investigate their impact on characteristics and chemical composition of biochars. As pyrolysis temperature increased, ash content, pH, electrical conductivity, basic functional groups, carbon stability, and total content of C, N, P, K, Ca, and Mg increased while biochar yield, total content of O, H and S, unstable form of organic C and acidic functional groups decreased. The ratios of O/C, H/C, (O + N)/C, and (O + N + S)/C tended to decrease with temperature. The data of Fourier transformation infrared indicate an increase in aromaticity and a decrease in polarity of biochar produced at a high temperature. With pyrolysis temperature, cellulose loss and crystalline mineral components increased, as indicated by X-ray diffraction analysis and scanning electron microscope images. Results suggest that biochar pyrolized at high temperature may possess a higher carbon sequestration potential when applied to the soil compared to that obtained at low temperature.

Conocarpus biochar as a soil amendment for reducing heavy metal availability and uptake by maize plants.

The objective of this study was to assess the use of Concarpus biochar as a soil amendment for reducing heavy metal accessibility and uptake by maize plants (Zea mays L.). The impacts of biochar rates (0.0, 1.0, 3.0, and 5.0% w/w) and two soil moisture levels (75% and 100% of field capacity, FC) on immobilization and availability of Fe, Mn, Zn, Cd, Cu and Pb to maize plants as well as its application effects on soil pH, EC, bulk density, and moisture content were evaluated using heavy metal-contaminated soil collected from mining area. The biochar addition significantly decreased the bulk density and increased moisture content of soil. Applying biochar significantly reduced NH4OAc- or AB-DTPA-extractable heavy metal concentrations of soils, indicating metal immobilization. Conocarpus biochar increased shoot dry biomass of maize plants by 54.5–102% at 75% FC and 133–266% at 100% FC. Moreover, applying biochar significantly reduced shoot heavy metal concentrations in maize plants (except for Fe at 75% FC) in response to increasing application rates, with a highest decrease of 51.3% and 60.5% for Mn, 28% and 21.2% for Zn, 60% and 29.5% for Cu, 53.2% and 47.2% for Cd at soil moisture levels of 75% FC and 100% FC, respectively. The results suggest that biochar may be effectively used as a soil amendment for heavy metal immobilization and in reducing its phytotoxicity.

Effect of Conocarpus Biochar Application on the Hydraulic Properties of a Sandy Loam Soil

Abstract Biochar research has received greater interest in recent years because of its potential beneficial effects on soil properties and its efficiency as a long-term C sequester. In this study, the effect of Conocarpus biochar application on the hydraulic properties of a sandy loam soil was investigated. Evaporation rate, water retention, soil water infiltration, and soil aggregate stability were measured in soil columns packed with a sandy loam soil amended with 5, 10, 15, and 20 g [BULLET OPERATOR] kgu2009−u20091 of non-activated biochar. Results showed that cumulative evaporation was reduced by 5.4% to 12.1% as a result of increasing biochar application. The application of biochar enhanced the capacity of the soil to retain water by 8.9%, 17.6%, 28.1%, and 30.9% for soils treated with biochar rates of 5, 10, 15, and 20 g [BULLET OPERATOR] kgu2009−u20091, respectively. Water content at field capacity increased in the top 10 cm by 7.2% to 15.9%. Water-holding capacity was increased by increasing the application rate of biochar. The percentage of water-stable aggregates was increased, especially in the larger fractional sizes (2–0.25 mm). On the other hand, the application of biochar decreased saturated hydraulic conductivity and infiltration rate, but had minimal effect on other hydraulic parameters. The ability of biochar to reduce water evaporation and improve water retention of coarse-textured sandy soils can help to enhance soil quality and productivity, reduce the amount of irrigation water, and maintain crop yields for crops exposed to water stress, especially in arid and semiarid regions.

Carbon mineralization and nutrient availability in calcareous sandy soils amended with woody waste biochar

Many studies have reported the positive effect of biochar on soil carbon sequestration and soil fertility improvement in acidic soils. However, biochar may have different impacts on calcareous sandy soils. A 90-day incubation experiment was conducted to quantify the effects of woody waste biochar (10 g kg(-1)) on CO2-C emissions, K2SO4-extractable C and macro-(N, P and K) and micro-(Fe, Mn, Zn and Cu) nutrient availability in the presence or absence of poultry manure (5 g kg(-1) soil). The following six treatments were applied: (1) conocarpus (Conocarpus erectus L.) waste (CW), (2) conocarpus biochar (BC), (3) poultry manure (PM), (4) PM+CW, (5) PM+BC and (6) untreated soil (CK). Poultry manure increased CO2-C emissions and K2SO4-extractable C, and the highest increases in CO2-C emission rate and cumulative CO2-C and K2SO4-extractable C were observed for the PM+CW treatment. On the contrary, treatments with BC halted the CO2-C emission rate, indicating that the contribution of BC to CO2-C emissions is negligible compared with the soils amended with CW and PM. Furthermore, the combined addition of PM+BC increased available N, P and K compared with the PM or BC treatments. Overall, the incorporation of biochar into calcareous soils might have benefits in carbon sequestration and soil fertility improvement.

Chemically Modified Biochar Produced from Conocarpus Wastes: An Efficient Sorbent for Fe(II) Removal from Acidic Aqueous Solutions

Fe(II) removal from acidic aqueous solutions using Conocarpus sp. biochar or chemically modified biochar prepared by synthesizing Mg(OH)2 on biochar surface as well as their comparison with zeolite sorbent (natural clinoptilolite) was investigated. Batch experiments were conducted as a function of initial pH of 2–5, contact time of 5–180 minutes and initial concentration of 10–200 mg l−1 (0.18–3.58 mmol l−1). The sorption data indicated that the pseudo-second-order kinetic model was the best model to simulate adsorption of Fe(II) onto the all sorbents and could generally be described by the Freundlich model. The higher sorption capacities for Fe(II) ions were generally pronounced for chemically modified biochar (84.6–99.8%) followed by biochar (38.3–97.6%) than those that were achieved by zeolite (12.3–95.5%). Thus, remediating acidic wastewater contaminated with Fe(II) might be possible using Conocarpus biochar, especially the chemically modified biochar.

Conocarpus Biochar Induces Changes in Soil Nutrient Availability and Tomato Growth Under Saline Irrigation

Thermally modified organic materials commonly known as biochar have gained popularity of being used as a soil amendment. Little information, however, is available on the role of biochar in alleviating the negative impacts of saline water on soil productivity and plant growth. This study, therefore, was conducted to investigate the effects of Conocarpus biochar (BC) and organic farm residues (FR) at different application rates of 0.0% (control), 4.0% and 8.0% (weight/weight) on yield and quality of tomatoes grown on a sandy soil under drip irrigation with saline or non-saline water. The availability of P, K, Fe, Mn, Zn and Cu to plants was also investigated. The results demonstrated clearly that addition of BC or FR increased the vegetative growth, yield and quality parameters in all irrigation treatments. It was found that salt stress adversely affected soil productivity, as indicated by the lower vegetative growth and yield components of tomato plants. However, this suppressing effect on the vegetative growth and yield tended to decline with application of FR or BC, especially at the high application rate and in the presence of biochar. Under saline irrigation system, for instance, the total tomato yield increased over the control by 14.0%–43.3% with BC and by 3.9%–35.6% with FR. These could be attributed to enhancement effects of FR or BC on soil properties, as indicated by increases in soil organic matter content and nutrient availability. Therefore, biochar may be effectively used as a soil amendment for enhancing the productivity of salt-affected sandy soils under arid conditions.

The water quality index and hydrochemical characterization of groundwater resources in Hafar Albatin, Saudi Arabia

The main objectives of this study were to: evaluate and compare the treated and untreated groundwater quality in Hafar Albatin, Saudi Arabia for drinking purpose using water quality index (WQI), study the suitability of untreated groundwater for irrigation purpose, and investigate hydrochemical processes that control the groundwater chemistry. The WQI calculations required several physiochemical water parameters including EC, pH, Ca2+, Mg2+, Na+, K+, Cl−, SO42−, and NO3−. The results showed that more than 47xa0% of the untreated wells considered unsuitable (class V), 39xa0% considered very poor water (class IV), and 14xa0% considered poor water (class III) for drinking purposes. The treatment of groundwater improved its quality to poor (class III) and even good (class II). Approximately 64xa0% of all treated waters were of good quality; however, the rest remained poor. Most studied untreated groundwaters were considered unsuitable for irrigation due to salinity hazards; however, no sodicity hazards were anticipated. US salinity laboratory diagram revealed that the groundwater samples were grouped into five categories; 53.6xa0% of water samples were distributed in category C4–S2 highlighting very high salinity hazards and medium sodium hazards class. Durov and Piper diagrams revealed that the majority of investigated waters were sodium chloride and calcium sulfate–chloride water type. The Gibbs’s diagram revealed that the chemical weathering of rock-forming minerals and evaporation are influencing the groundwater quality. The hydrochemical modeling indicated that all water samples were undersaturated for halite and 89xa0% of water samples were saturated for anhydrite and gypsum.

Quality assessment of various bottled waters marketed in Saudi Arabia

This study focuses on the chemical analysis of the available brands of domestic bottled water in Riyadh City, Saudi Arabia. The distribution of the chemical constituents (major, minor, and trace elements) is determined and compared with the chemical content labeled on the bottles and with drinking water standards of Saudi Arabian, World Health Organization, and U.S. Environmental Protection Agency. The obtained results indicated that except for fluoride and bromate, the concentrations of dissolved salts, soluble cations and anions, nitrate, and trace elements of most bottled waters on sale were within the permissible limits set by standards used. On the other hand, the comparison between determined and reported label values recorded a substantial variation in some parameter values. Results indicated that more than 18xa0% of the sampled bottled waters exceeded the allowable limits for drinking water. Generated Piper diagrams revealed that the majority of investigated waters were sodium chloride–sulfate type; however, the hydrochemical modeling indicated that all water samples were undersaturated for anhydrite, gypsum, and halite.

Chemically modified biochar produced from conocarpus waste increases NO3 removal from aqueous solutions.

AbstractBiochar has emerged as a universal sorbent for the removal of contaminants from water and soil. However, its efficiency is lower than that of commercially available sorbents. Engineering biochar by chemical modification may improve its sorption efficiency. In this study, conocarpus green waste was chemically modified with magnesium and iron oxides and then subjected to thermal pyrolysis to produce biochar. These chemically modified biochars were tested for NO3 removal efficiency from aqueous solutions in batch sorption isothermal and kinetic experiments. The results revealed that MgO-biochar outperformed other biochars with a maximum NO3 sorption capacity of 45.36xa0mmolxa0kg−1 predicted by the Langmuir sorption model. The kinetics data were well described by the Type 1 pseudo-second-order model, indicating chemisorption as the dominating mechanism of NO3 sorption onto biochars. Greater efficiency of MgO-biochar was related to its high specific surface area (391.8xa0m2xa0g−1) and formation of strong ionic complexes with NO3. At an initial pH of 2, more than 89xa0% NO3 removal efficiency was observed for all of the biochars. We conclude that chemical modification can alter the surface chemistry of biochar, thereby leading to enhanced sorption capacity compared with simple biochar.n

Hydrochemical characterization of groundwater under agricultural land in arid environment: a case study of Al-Kharj, Saudi Arabia

This study focuses on chemical analysis of 180 different groundwater samples in Al-Kharj governorate, Saudi Arabia. The distribution of chemical constituents (major, minor, and trace elements) is determined and compared with drinking and irrigation water standards. The water quality index (WQI) is applied to investigate groundwaters suitability for drinking. The obtained results indicated that the concentrations of dissolved salts, soluble cations and anions, and nitrate, were above permissible limits set by drinking water standards, WHO, for most wells. The WQI concluded that 65.2xa0% of studied wells are considered poor water “class (III)”, 24.9xa0% are very poor water “class (IV)”, 6.1xa0% are unsuitable water for drinking “class (V)”, and only 3.9xa0% are good water for drinking or “class (II). Most groundwater is contaminated with nitrate with an average concentration of 14.7xa0mgxa0L−1. The water evaluation for irrigation poses that 69.4xa0% of studied wells are classified as moderately saline; however, the remaining are classified as severe saline water. The US Salinity Laboratory’s diagram reveals that majority of studied waters fall in class C4–S1, the area of very high salinity and low sodium hazards. Durov and Piper diagrams revealed that the majority of investigated waters are magnesium-calcium/sulfate–chloride water type. The Gibbs’s diagram revealed that the chemical weathering of rock-forming minerals and evaporation are influencing the groundwater quality. The hydrochemical modeling indicates that all water samples are undersaturated for halite and saturated for anhydrite and gypsum. The approach of this research could be applicable to similar situations worldwide.