Pyrolysis temperature and steam activation effects on sorption of phosphate on pine sawdust biochars in aqueous solutions

Biochar can be used as an adsorbent for phosphate removal in aquatic environments to treat eutrophication problems. Designing biochars that have large phosphate adsorption capacity through altering pyrolysis conditions and applying activation techniques will improve phosphate removal efficiency. In this study, four pine sawdust biochars were produced at 300 and 550 °C with and without steam activation. Batch sorption experiments including isotherm and kinetic studies were conducted to understand how phosphate removal capabilities and adsorption mechanisms of biochars were affected by pyrolysis temperature and steam activation. Our results showed that the steam activation and pyrolysis temperature did not affect phosphate adsorption by the biochars. The four biochars removed <4% of phosphate from the aqueous solution, which were not affected by the pH of the solution and biochar application rate. The repulsion forces between biochar surfaces and phosphate ions were likely the cause of the low adsorption.     

Effective Inhibition of Ammonium Released from Heavily Contaminated Sediments through Selective Oxidation with Zeolite Layer

Abstract

In order to study the remediation effect of heavily contaminated sediments, the experiments to repair heavily contaminated sediments were carried out under selective and nonselective oxidation conditions. Results showed that a lot of denitrifying bacteria was detected on the surface of modified zeolite by fluorescence in situ hybridization (FISH) after inoculating both nitrifying and denitrifying bacteria for 7?days. Up to 3.69?mg/g, in-situ regeneration of ammonium on zeolite loading with high ammonium (ammonium adsorption: 4.20?m/g) was obtained, which was 1.42 times that of nonselective oxidation (2.60?mg/g). This indicated that the in-situ regeneration rate of zeolite under high ammonium adsorption (5.0?mg/g) and high bacterial inoculum (80?mL/g) was enhanced. Moreover, only 1.50?mg/L total nitrogen with 84% inhibition in the overlying water under selective oxidation conditions was observed, which was 2.37 times the inhibition percentage of modified zeolite under nonselective oxidation conditions. The results illuminated that effective inhibition of ammonium released from heavily contaminated sediments can be achieved through selective oxidation with zeolite layer. At the same time, the in-situ service life of attached biofilm-modified zeolite under selective oxidation conditions was 5.87?years, which was extended by 3?years compared with nonselective oxidation conditions.     

The use of olive tree pruning waste compost to sequestrate methylene blue dye from aqueous solution

Considering that quality water supplies are diminishing and climate disorder affects water cycle, wastewaters should be decontaminated for reuse either by the same establishment or in agriculture for the growth of industrial plants. In that context, much research work has been focused on the development of low cost biosorbents. In this study, the effect of composting on the adsorption capacity of olive tree pruning waste (OTPW) biomass for methylene blue (MB) removal from aqueous solutions was examined. Composting procedure may improve the sorption properties of the raw organic materials, is economical and easy to apply. MB adsorption on both OTPW and composted olive tree pruning waste (COTPW) biomasses was found to be fast. The maximum monolayer adsorption capacity obtained from Langmuir isotherm was estimated to be 129.87 and 250.00 mg/g for OTPW and COTPW, respectively, indicating that composting procedure greatly improved the adsorptive properties of OTPW. The raise of temperature from 25°C to 60°C decreased the efficiency of OTPW for MB removal whereas the adsorption capacity of COTPW was not affected at high temperatures. Moreover, COTPW showed constant adsorption over the 2–8 solution pH range.     

Sorption of bisphenol A, 17α-ethinyl estradiol and phenanthrene on thermally and hydrothermally produced biochars

Thermal and hydrothermal biochars were characterized, and adsorption of bisphenol A (BPA), 17α-ethinyl estradiol (EE2) and phenanthrene (Phen) was determined to investigate the sorption characteristic difference between the two types of biochars. Thermal biochars were composed mostly of aromatic moieties, with low H/C and O/C ratios as compared to hydrothermal ones having diverse functional groups. Single-point organic carbon-normalized distribution coefficients (logK_OC) of EE2 and BPA of hydrothermal biochars were higher than thermal biochars, while Phen logK_OC values were comparable among them. X-ray diffraction and solid state nuclear magnetic resonance results suggested that hydrothermal biochars consisted of more amorphous aliphatic-C, possibly being responsible for their high sorption capacity of Phen. This study demonstrated that hydrothermal biochars could adsorb a wider spectrum of both polar and nonpolar organic contaminants than thermally produced biochars, suggesting that hydrothermal biochar derived from poultry and animal waste is a potential sorbent for agricultural and environmental applications.     

Adsorption of Cd(II) by rhizosphere and non-rhizosphere soil originating from mulberry field under laboratory condition

In this study, the adsorption behavior of Cd ions by rhizosphere soil (RS) and non-rhizosphere soil (NS) originated from mulberry field was investigated. The Langmuir, Freundlich and the Dubinin–Radushkevich (D-R) equations were used to evaluate the type and efficiency of Cd adsorption. The RS was characterized by lower pH but the higher content of soil organic matter and cation exchange capacity (CEC) as compared to NS. Also, the maximum adsorption of Cd²⁺ for RS (5.87 mg/g) was slightly bigger than that for NS (5.36 mg/g). In Freundlich isotherm, the K_f of the adsorption of Cd²⁺ to surface of the RS components was higher than that of the NS, indicating stronger attraction between Cd²⁺ and components of the RS. According to the D-R model, the adsorption of Cd²⁺ by both soils was dominated by ion exchange phenomena. These results indicated that mulberry roots modified physical and chemical properties of the RS under field conditions, which also affected the Cd sorption efficiency by soil components during laboratory experiments. Current knowledge of the Cd²⁺ sorption processes in the rhizosphere of mulberry may be important if these trees are planted for use in phytoremediation of Cd contaminated soils.     

Chromium Removal from Aqueous System and Industrial Wastewater by Agricultural Wastes

This study involved the development of formaldehyde-treated, deseeded sunflower head waste–based biosorbent (FSH) for the biosorption of Cr(VI) from aqueous solution and industrial wastewater. Batch-mode experiments were conducted to determine the kinetics, sorption isotherms, effect of pH, initial Cr(VI) concentration, biosorbent dose, and contact time. The results demonstrated that FSH can sequester Cr(VI) from the aqueous solution. The maximum sorption occurred at pH = 2.0, biosorbent dose = 4.0 g/L, concentration of 100 mg/L at 25°C at 180 rpm after 2 h contact time. The FSH had an adsorption capacity of 7.85 mg/g for Cr(VI) removal at pH 2.0. The rate of adsorption was rapid, and equilibrium was attained within 2 h. The equilibrium sorption data fitted the Langmuir isotherm model, which was further confirmed by the chi-square test.     

Pyrogenic temperature affects the particle size of biochar-supported nanoscaled zero valent iron (nZVI) and its silver removal capacity

Particle size of nanoscaled zero valent iron (nZVI) in nanocomposites can be affected by support materials. In this work, nZVI was supported by bamboo-derived biochars produced at 450 °C (BBL) and 600 °C (BBH). Total iron (Fe) contents were 14.4 and 11.9% for nZVI immobilized in BBL (nZVI/BBL) and BBH (nZVI/BBH), respectively. The resultant nanocomposites were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and scanning electron microscopy/energy-dispersive X-ray analyses (SEM/EDS). The nZVI was successfully embedded in biochar pores and surfaces as confirmed by SEM/EDS and XRD. TEM revealed that particle sizes of nZVI in nZVI/BBL and nZVI/BBH were roughly 26 and 40 nm, respectively. The Ag⁺ sorption isotherms (25–300 mg L^?1 Ag⁺) suggested that 1 kg of nZVI in nZVI/BBL and nZVI/BBH removed as much as 745.5 and 534.5 g Ag⁺, respectively. The results suggested that Ag⁺ removal capacity was related to particle size of nZVI, which was also affected by pyrogenic temperature.     

Arsenic and fluoride removal by potato peel and rice husk (PPRH) ash in aqueous environments

Finding appropriate adsorbent may improve the quality of drinking water in those regions where arsenic (As) and fluoride (F^?) are present in geological formations. In this study, we evaluated the efficiency of potato peel and rice husk ash (PPRH-ash)-derived adsorbent for the removal of As and F from contaminated water. Evaluation was done in batch adsorption experiments, and the effect of pH, initial adsorbate concentration, contact time, and adsorbent dose were studied. Characteristics of adsorbents were analyzed using scanning electron micropcope (SEM) and Fourier transform infrared (FTIR) spectroscopy. Both the Langmuir and Freundlich isotherm models fitted well for F^? and As sorption process. The maximum adsorption capacity of adsorbent for As and F^? was 2.17 μg g^?1 and 2.91 mg g^?1, respectively. The As and Fi removal was observed between pH 7 and 9. The sorption process was well explained with pseudo-second order kinetic model. Arsenic adsorption was not decreased in the presence of carbonate and sulfate. Results from this study demonstrated potential utility of this agricultural biowaste, which could be developed into a viable filtration technology for As and F^? removal in As- and F-contaminated water streams.     

Monitoring the Changes of Chemical Properties of Rice Straw–Derived Biochars Modified by Different Oxidizing Agents and Their Adsorptive Performance for Organics

Biochar derived from agricultural biomass waste is increasingly recognized as a multifunctional material for various applications according to its characteristics. In this study, rice straw–derived biochars were produced at different temperatures (550, 650, 750°C), then they were modified by using different oxidizing agents, including KOH, HNO₃, H₂SO₄, H₂O₂, and KMnO_4. The influence of carbonization temperature and the oxidizing agent's nature on the surface chemistry was investigated. Fourier transform infrared (FTIR) analysis detected lactone, carbonyl, quinone or conjugated quinone, carboxyl-carbonate structure, and alcohol groups in most of the oxidized samples. Modified biochars have low pH values compared with their parent biochars. This is due to the fact that most treatments of biochar increase the acidic functional groups on the surface. Modified biochars presented greater capacities for adsorption of organic species of different molecular sizes such as iodine, phenol, and methylene blue from solutions. Such behavior proves that the most important surface properties of these biochars affecting their solution adsorption behavior are their acidity/alkalinity and hydrophilicity.     

Comparative evaluation for the sorption capacity of four carbonaceous sorbents to phenol

Sorption kinetics and isotherms of phenol by four carbonaceous sorbents (activated carbon (AC), mesoporous carbon (MPC), bamboo biochar (BBC) and oak wood biochar (OBC)) were compared in this study. MPC has the fastest sorption rate and initial sorption potential, which were indicated by sorption rate constants and initial sorption rate “h” in a pseudo-second-order kinetic model. The ordered and straight pore structure of MPC facilitated the accessibility of phenol. The AC showed the greatest sorption capacity towards phenol with maximum sorption of 123 mg/g as calculated by the Langmuir model. High surface area, complexity of pore structure, and the strong binding force of the π–π electron-donor-acceptor interaction between phenol molecules and AC were the main mechanisms. The BBC and OBC had much slower sorption and lower sorption capacity (33.04 and 29.86 mg/g, respectively), compared to MPC (73.00 mg/g) and AC, indicating an ineffective potential for phenol removal from water.     

Cadmium adsorption by non-living biomass of the semi-macroscopic brown alga,Ectocarpus siliculosus,grown in axenic mass culture and localisation of the adsorbed Cd by transmission electron microscopy

Non-living, freeze-dried material of the brown algaEctocarpus siliculosus (Phaeophyceae) demonstrated high equilibrium uptake of Cd from aqueous solutions (Fehrmann & Pohl, 1993). The alga was grown in 250-L photobioreactors under various growth conditions (light, salinity and nutrient concentrations) in order to obtain larger quantities of biomass and to improve its Cd adsorption capacity. To derive further knowledge on the biosorbant phenomenon different adsorption parameters such as pH for the sorption process and kinetics of Cd adsorption were tested. The maximum adsorption capacity of the freeze-dried biomass exceeded 41 mg Cd per g biomass. After repeated addition of low Cd concentrations the maximum adsorption capacity was lower (31.4 mg Cd per g biomass). In comparison with other adsorbing materials (activated carbon, silica gel, siliceous earth)E. siliculosus showed significantly higher adsorption capacity. Desorption of deposited Cd with 0.1 M HCl resulted in no changes of the adsorption capacity through five subsequent adsorption-/desorption-cycles. Hence, driedE. siliculosus appears to be an efficient material for the elimination of Cd from industrial waste water.Transmission electron microscopic investigations showed an electron dense area in the outer surface layers of the cell wall after Cd adsorption indicating the most likely location of Cd fixation.Author for correspondence     

A combination method based on chitosan adsorption and duckweed (Lemna gibba L.) phytoremediation for boron (B) removal from drinking water

The metalloid boron (B) and its compounds widely exist in the environment, and boron can have hazardous effects on plants, animals, and human beings when it is found in high concentrations in water bodies. It is difficult and costly to remove B with conventional treatment methods from drinking water. Therefore, alternative and cost-effective treatment techniques are necessary. In this study, for the first time, a novel and environmentally friendly method based on the phytoremediation ability of chitosan and duckweed (Lemna gibba L.) combination was evaluated for B removal from drinking water. Our results from batch adsorption experiment indicated that the highest B uptake capacity of chitosan bead was found as 3.18 mg/g, and we determined the optimal B sorption occurs at pH value of 7. The Langmuir isotherm and pseudo-second-order kinetic model better fitted the equilibrium obtained for B removal. B in drinking water could be reduced to less than 2.4 mg L ^?1 when 0.05 g of plant-based chitosan beads and 12 L. gibba fronds were used in the 4-day treatment period.     

Biochars from local agricultural waste residues contribute to soil quality and plant growth in a Cerrado region (Brazil) Arenosol

Arenosols (sandy soils) in the Cerrado region of Mato Grosso, Brazil, are increasingly used for maize production, the second most important crop in the region after soybean. Yet, these soils are typically nutrient poor with low soil water retention, requiring high fertilizer inputs that are often lost in surface runoff or leached. The addition of biochar, a more recalcitrant organic amendment, may therefore be beneficial in Cerrado Arenosols, contributing to sustainable crop production in the region. To examine biochar contribution to soil nutrient levels and maize growth in a Cerrado Arenosol, we conducted a greenhouse experiment using biochars made from local agricultural waste feedstocks. These were cotton husks, swine manure, eucalyptus sawmill residue, and sugarcane filtercake, pyrolyzed at 400 °C, and applied to soil at five rates: 0%, 1%, 2%, 3%, and 4% by weight. Maize plants were grown under unstressed conditions (e.g., no nutrient or water limitations) to highlight any possible negative effects of the biochars. After 42 days, soils were analyzed for nutrient levels, and plant physical and physiological measurements were taken. Filtercake biochar had the highest plant biomass and physiological properties (e.g., photosynthesis, respiration, nitrogen use efficiency), while cotton biochar had the lowest. Importantly, maize biomass decreased with increasing application rates of cotton and swine manure biochars, while biomass did not vary in response to biochar application rate for filtercake and eucalyptus biochars. In this study, we found that while each biochar exhibited potential for improving chemical and physical properties of Cerrado Arenosols, filtercake biochar stood out as most promising. Biochar application rate was identified a key factor in ensuring crop productivity. Transforming these agricultural residues readily available in the region into more stable biochar can thus contribute to sustainable crop management and soil conservation, providing an alternative form of waste disposal for these residual materials.     

Preparation and Characterization of Chemically Modified Silk Cotton Hull Activated Carbon and Its Effects on Cd(II) Removal from Aqueous Solutions

The novel biosorbent silk cotton hull, an agrowaste material, has been successfully utilized for the removal of cadmium(II) from aqueous solutions. The adsorption of cadmium onto three kinds of activated biosorbent has been studied: modified by concentrated sulfuric acid alone (AC), a mixture of concentrated sulfuric acid and hydrogen peroxide (AC1), and a mixture of concentrated sulfuric acid and ammonium persulfate (AC2). The adsorption studies were carried out to optimize the process parameters such as pH, adsorbent dosage, contact time, and initial metal ion concentration. Maximum metal removal was observed at pH 7.0 with a contact time of 90 min at stirring speed of 200 rpm with an adsorbent dosage of 4.0 g L^?1. The sorption isotherms were studied using the Langmuir, Freundlich, and Tempkin isotherm models. The maximum adsorption capacities were 100.00, 142.86, and 142.87 mg g^?1 for AC, AC1, and AC2, respectively. Accordingly, the surface modification of the activated carbons AC1 and AC2 enhanced cadmium removal greatly. The experiments demonstrated that the removal of metal ions followed the pseudo-second-order kinetic model. The sorption mechanism is discussed in terms of the activated surface properties. A relationship between the oxygen content and sorption was found in this novel material. Desorption experiments were carried out using hydrochloric acid with a view to generate the spent adsorbent and to recover the adsorbed metal ions.     

不同炭化温度制备的蚕丝被废弃物生物炭对重金属Cd2+的吸附性能

以蚕丝被废弃物为原料,在300、500和700 ℃高温缺氧条件下热解炭化制备成3种生物炭(BC300、BC500和BC700).利用扫描电镜(SEM)、傅里叶红外光谱仪(FT-IR)、X-射线衍射仪(XRD)、比表面积分析仪等对其理化性质进行表征,并研究了不同温度下制备的生物炭对溶液中Cd²⁺的吸附特性.结果表明: 随着炭化温度上升,BET比表面积、pH、灰分均增大,生物炭表面形态结构越来越不规则.XRD结果显示:不同温度下获得的生物炭中均含有一定量的方解石,FT-IR光谱图上的峰主要为-OH和方解石典型的吸收峰;pH对生物炭吸附Cd²⁺的影响不大;Langmuir方程能更好地拟合3种生物炭对Cd²⁺的吸附等温过程,其最大吸附量分别为25.61、52.41和91.07 mg·g^-1.3种生物炭对Cd²⁺吸附过程均更符合准二级动力学方程,且BC700对Cd²⁺的吸附效果最佳.进一步研究离子浓度及阳离子共存对BC700吸附Cd²⁺的影响,结果显示: NaCl浓度越高,对Cd²⁺的吸附抑制越明显;共存阳离子中,Ca²⁺和Mg²⁺对Cd²⁺的吸附抑制更明显,而K⁺几乎无影响.因此,以蚕丝被废弃物制备的生物炭作为去除水体中Cd²⁺的吸附剂具有较强的应用潜力.     

Effect of Pyrolysis Temperature on Chemical and Surface Properties of Biochar of Rapeseed (Brassica napus L.)

The biochar is an important carbon-rich product that is generated from biomass sources through pyrolysis. Biochar (charcoal) can be both used directly as a potential source of solid biofuels and as soil amendments for barren lands. The aim of this study was investigate influence of pyrolysis temperature on the physicochemical properties and structure of biochar. The biochars were produced by pyrolysis of rapeseed (Brassica napus L.) using a fixed-bed reactor at different pyrolysis temperatures (400–700°C). The produced biochars were characterized by proximate and elemental analysis, Brunauer–Emmett–Teller (BET) surface area, particle size distributions, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy. The results showed that both chemical and surface properties of the biochars were significantly affected by the pyrolysis temperature. Aromatic hydrocarbons, hydroxyl and carbonyl compounds were the majority components of the biochar. The biochar obtained at 700°C had a high fixed carbon content (66.16%) as well as a high heating value, and therefore it could be used as solid fuel, precursor in the activated carbons manufacture (specific surface area until 25.38 m² g^?1), or to obtain category-A briquettes.     

Phosphorus sorption capacity of biochars from different waste woods and bamboo

Four biochars were made via pyrolysis at 500?°C using different waste plant materials, including tree branches from Cinnamonum campora (L.) Pres (CCP), Eriobotrya japonica (Thunb.) Lindl (EJL), Rohdea roth (RR) and bamboo shoots (Phyllostachys sulphurea) (PS). Phosphorus sorption capacities of the biochars were studied by isothermal experiments on their sorption kinetics. Results show that P sorption to the three wood biochars (CCP, EJL, and RR) fitted well with Lagergren pseudo second order model. However, P release was found in the PS biochar and sand amended with the PS biochar treatments during the isothermal sorption experiment. Phosphorus sorption capacity of the CCP biochar, EJL biochar and RR biochar was 4,762.0, 2, 439.0 and 1, 639.3?mg/kg, respectively. The CCP biochar showed the highest P sorption capacity due to its higher pH, lower dissolved P content, larger surface area (23.067 m²/g) and pore volume (0.058?cm³/g). The PS biochar showed the lowest P sorption due to its higher dissolved P content, more carboxyl groups, and smaller surface area (2.982 m²/g) and pore volume (0.017?cm³/g). Results suggest that the CCP biochar could be a potential alternative adsorbent for P sorption, such as removing P in wastewater treatment by constructed wetlands.     

A Novel Microbial Biofilm for Bioremoval of Nickel from Aqueous Media

This study evaluated the efficacy of a microbial biofilm in removing Ni ions in aqueous media. The biofilm was developed incorporating a garden soil fungus with a bacterium isolated from Ni-rich serpentinite soil. The biofilm was characterized using microscopy, scanning electron microscopy, Fourier transform infrared (FTIR) investigations, and Boehm and potentiometric titrations. Ni removal was determined using batch experiments as a function of pH, Ni concentration, and time. The adsorption isotherm assay was conducted with varying Ni concentrations from 25 to 500 mg/L for 4 days. Isotherm and kinetic modeling were applied to the experimental data to understand the mechanisms of Ni removal. The zero point charge at pH 4.5 indicated the pH values greater than 4.5 is favorable for Ni adsorption. Acidic nature of the biofilm was reflected from Boehm titration data showing higher number of acidic groups than basic groups. With the increase in initial Ni concentration, the uptake increased from 3.43 to 38.16 mg/g. Hill, the best-fitted isotherm model, indicated a maximum adsorption capacity of 165.37 mg/g. After 4 days, the adsorption rate reached an equilibrium with a maximum sorption of ～30 mg/g for an initial concentration of 100 mg/L. Kinetic model fitting with Power function further demonstrated the chemisorptive interaction of Ni with the biofilm surface. A clear involvement of functional groups of the biofilm in Ni bonding was observed from the attenuated total reflection (ATR)-FTIR spectrum. The microbial biofilm showed an efficient but slow removal of Ni from aqueous media.     

Effects of Feedstock and Pyrolysis Temperature on Biochar Adsorption of Ammonium and Nitrate

Biochar produced by pyrolysis of biomass can be used to counter nitrogen (N) pollution. The present study investigated the effects of feedstock and temperature on characteristics of biochars and their adsorption ability for ammonium N (NH₄ ⁺-N) and nitrate N (NO₃ ⁻-N). Twelve biochars were produced from wheat-straw (W-BC), corn-straw (C-BC) and peanut-shell (P-BC) at pyrolysis temperatures of 400, 500, 600 and 700°C. Biochar physical and chemical properties were determined and the biochars were used for N sorption experiments. The results showed that biochar yield and contents of N, hydrogen and oxygen decreased as pyrolysis temperature increased from 400°C to 700°C, whereas contents of ash, pH and carbon increased with greater pyrolysis temperature. All biochars could sorb substantial amounts of NH₄ ⁺-N, and the sorption characteristics were well fitted to the Freundlich isotherm model. The ability of biochars to adsorb NH₄ ⁺-N followed: C-BC>P-BC>W-BC, and the adsorption amount decreased with higher pyrolysis temperature. The ability of C-BC to sorb NH₄ ⁺-N was the highest because it had the largest cation exchange capacity (CEC) among all biochars (e.g., C-BC400 with a CEC of 38.3 cmol kg⁻¹ adsorbed 2.3 mg NH₄ ⁺-N g⁻¹ in solutions with 50 mg NH₄ ⁺ L⁻¹). Compared with NH₄ ⁺-N, none of NO₃ ⁻-N was adsorbed to biochars at different NO₃ ⁻ concentrations. Instead, some NO₃ ⁻-N was even released from the biochar materials. We conclude that biochars can be used under conditions where NH₄ ⁺-N (or NH₃) pollution is a concern, but further research is needed in terms of applying biochars to reduce NO₃ ⁻-N pollution.     

Physical,Chemical and Biological Characterization of Six Biochars Produced for the Remediation of Contaminated Sites

The physical and chemical properties of biochar vary based on feedstock sources and production conditions, making it possible to engineer biochars with specific functions (e.g. carbon sequestration, soil quality improvements, or contaminant sorption). In 2013, the International Biochar Initiative (IBI) made publically available their Standardized Product Definition and Product Testing Guidelines (Version 1.1) which set standards for physical and chemical characteristics for biochar. Six biochars made from three different feedstocks and at two temperatures were analyzed for characteristics related to their use as a soil amendment. The protocol describes analyses of the feedstocks and biochars and includes: cation exchange capacity (CEC), specific surface area (SSA), organic carbon (OC) and moisture percentage, pH, particle size distribution, and proximate and ultimate analysis. Also described in the protocol are the analyses of the feedstocks and biochars for contaminants including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), metals and mercury as well as nutrients (phosphorous, nitrite and nitrate and ammonium as nitrogen). The protocol also includes the biological testing procedures, earthworm avoidance and germination assays. Based on the quality assurance / quality control (QA/QC) results of blanks, duplicates, standards and reference materials, all methods were determined adequate for use with biochar and feedstock materials. All biochars and feedstocks were well within the criterion set by the IBI and there were little differences among biochars, except in the case of the biochar produced from construction waste materials. This biochar (referred to as Old biochar) was determined to have elevated levels of arsenic, chromium, copper, and lead, and failed the earthworm avoidance and germination assays. Based on these results, Old biochar would not be appropriate for use as a soil amendment for carbon sequestration, substrate quality improvements or remediation.