산업혁명 이후 화석연료 사용의 급격한 증가와 온실가스 배출이 심해져 온난화 경향이 심각해 탄소 배출을 절감하는 상황이 요구되고 있다. 본 연구는 탄소 격리 효과를 가지고 있는 바이오차와 콘크리 트의 취성을 극복하고 연성을 증가시켜 균열의 발생을 최소화하여 내구성을 향상 시킬 수 있는 PVA (Polyvinyl Acohol)섬유를 활용하여 기존의 콘크리트의 단점을 보완하고, 시멘트 저감 효과와 친환경 성을 갖춘 고연성 섬유보강 시멘트 복합체(ECC)를 제작하여 바이오차 시멘트 대체 비율에 따른 ECC 의 역학적 특성을 분석하고 비교하였다. 바이오차 시멘트 대체 비율 5%를 최대치로 설정하여 시멘트 대체 비율을 1%씩 올려 0%, 1%, 2%, 3%, 4%, 5%까지 설정하여 플로우 시험, 압축강도 실험, 쪼갬 인장 강도 실험, 휨 강도 실험을 진행하였다. 모르타르의 유동성을 평가하기 위해 플로우 시험을 실시 했으나, 바이오차 시멘트 대체 비율에 관계없이 플로우는 큰 차이를 보이지 않았다. 바이오차 시멘트 대체 비율에 따른 강도 비교를 위한 압축강도 실험, 쪼갬 인장 실험에서는 바이오차 시멘트 대체 비율 2%가 가장 높은 값을 보였다. 휨 강도 실험에서는 바이오차 시멘트 대체 비율 3%가 가장 큰 값을 보 였다. 휨 강도 실험에서는 바이오차를 혼입하지 않은 노말 ECC와 비교했을 때 바이오차의 시멘트 대 체율이 높아질수록 강도가 감소하였지만, 압축강도와 쪼갬 인장강도 실험에서는 대체율이 높아지면 강 도가 증가하는 경향이 나타났다.

세계적으로 환경에 대한 관심이 커지면서, 탄소 저감 및 탄소 중립을 위한 다양한 연구들이 진행되고 있다. 특히 최 근에는 탄소 포집 및 저장 기술인 CCS(Carbon Capture and Storage)에 주목이 높아졌다. 그뿐만 아니라, 대기 중의 탄소를 효과 적으로 저장하는 특성을 가진 바이오차는 탄소 중립에 기여할 수 있는 방안으로 다양한 연구가 진행되고 있다. 건설 산업에서 는 시멘트 대체재를 활용한 탄소 감소 관련 연구가 진행 중이며, 본 연구에서는 바이오차를 콘크리트 및 모르타르의 시멘트 대 체재로 활용하여 시멘트 사용량을 줄이고, 동시에 콘크리트 및 모르타르 내의 탄소를 포집하고 저장하여 탄소 배출량을 감소시 키고자 한다. 이를 위해 바이오차의 시멘트 치환율을 0%, 10%, 20%로 설정하고, 각각의 경우에 대해 콘크리트 및 모르타르의 슬럼프, pH 농도, 그리고 압축강도를 비교하였다.실험 결과에 따르면, 바이오차의 시멘트 치환율이 증가함에 따라 슬럼프와 압 축강도가 감소하는 경향을 보였으며, pH는 유사한 양상을 나타냈다.

Organic wastewater causes serious environmental pollution, and catalytic oxidation is promising technique for wastewater treatment. Developing green and effective catalysts is currently challenging. In this work, green synthesis of nano zerovalent iron loaded onto porous biochar derived from popcorn is conducted, and catalytic oxidation of Rhodamine B (RhB) is evaluated in the presence of H2O2. Effect of process factors is examined on catalytic performance for RhB removal. The mechanism of RhB removal is discussed by characterizations (Fourier transform infrared spectra and Raman) and UV–vis spectra. RhB removal is improved with high catalyst dosage, low initial RhB concentration, and high reaction temperature, while it is slightly influenced by carbonization temperature of biochar, H2O2 dosage and pH value. Under conditions of BC-250 1.0 g/L, H2O2 0.01 mol/L, pH 6.1, and temperature 30 °C, the removal rate of RhB is 92.27% at 50 min. Pseudo first-order kinetics is used to fitting experimental data, and the activation energy for RhB removal in BC-250/H2O2 system is 39 kJ/mol. RhB removal in BC-250/H2O2 system can be attributed to adsorption effect and catalytic oxidation with the dominant role of hydroxyl radical. This work gives insights into catalytic oxidation of organic wastewater using green catalyst.

Research is currently being conducted in the field of carbon reduction–related construction technologies, focusing on using industrial waste as a replacement for cement or as aggregates. However, the existing research is limited as carbon reduction is only achieved by reducing the amount of cement used. With the imperative of carbon neutrality, the development of carbon reduction technology is also necessary in the construction field. To address this, we plan to develop carbon reduction technology by introducing biochar—a carbon-sequestration material—into construction practices. Therefore, this study aims to comprehend the effect of the carbonization degree of biochar on the hydration reaction of cement, emphasizing the development of carbon-sequestration construction technology. Therefore, physical and chemical properties, such as surface and crystal structures, were analyzed to determine the effect of varying carbonization degrees on cement composites, contributing valuable insights into the broader field of sustainable construction.

Water contamination is one of the most pressing environmental issues of the present. There is a significant amount of interest in the slow pyrolysis of biomass to produce biochar, a solid byproduct that is stable and rich in carbon. Adsorbents manufactured from hydrochars, sometimes referred to as hydrochar created by hydrothermal methods, have been tested for the removal of possible contaminants from wastewater. The hydrothermal processes of hydrothermal carbonization (HTC) and liquefaction (HTL) yield hydrochars, a distinct category of biochar. Because of its peak efficiency, large surface area, large size of pore and capacity to regenerate, hydrochar is an acceptable option for the rehabilitation of a range of pollutants. The formation, activation, identification, and use of biochar and hydrochar were highlighted in this review. The physiochemical properties of the char produced by the two processes are very different, which has an impact on their potential uses in areas like wastewater pollution remediation, soil improvement, greenhouse gas emission and carbon sequestration among others.

This study evaluated the odor mitigation effect of rice husk biochar addition to the bedded pack dairy barn floor using lab-scale reactors for five days. Rice husk biochar mixed with dairy manure and sawdust mixture at different ratios (5%-addition test unit: adding biochar by 5% of the total solid weight of the mixture, 10%-addition test unit: adding biochar by 10% of the total solid weight of the mixture). Cumulative NH3 and H2S emissions of 10%-addition test unit were reduced by 26% (p< 0.05) and 46% (p = 0.0655), respectively, compared with control. However, 5%-addition test unit did not show NH3 and H2S emission reduction. Further research is needed to determine the appropriate level of biochar addition between 5 and 10%, and to evaluate applicability in the field through economic analysis.

There is an ever growing interest in the development of biochar from a large variety of agrowastes. Herein, the main objective is the conversion of pomegranate peel powder biochar and its post-functionalization by phosphoric acid treatment, followed by arylation organic reaction. The latter was conducted using in situ-generated diazonium salts of 4-aminobenzoic acid ( H2N-C6H4-COOH), sulfanilic acid ( H2N-C6H4-SO3H) and Azure A dye. The effect of diazonium nature and concentration on the arylation process was monitored using thermal gravimetric analysis (TGA) and Raman spectroscopy, scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). SEM pictures showed micrometer-sized biochar particles with tubular structure having about 10–20 μm-wide channels. SEM studies have shown that arylation did not affect the morphology upon arylation. The porous structure did not collapse and withstood the arylation organic reaction in acid medium did not collapse upon arylation. TGA and Raman indicated gradual changes in the arylation of biochar at initial concentrations 10– 5, 10– 4 and 10– 3 mol L− 1 of 4-aminobenzoic acid. The detailed Raman spectra peak fittings indicate that the D/G peak intensity ratio leveled off at 3.35 for 4-aminobenzoic acid initial concentration of 10– 4 mol L− 1, and no more change was observed, even at higher aryl group mass loading. This is in line with formation of oligoaryl grafts rather than the grafting of new aryl groups directly to the biochar surface. Interestingly, Azure A diazonium salt induced much lower extent of surface modification, likely due to steric hindrance. To the very best of our knowledge, this is the first report on diazonium modification of agrowaste-derived biochar and opens new avenues for arylated biochar and its applications.

The objective of this study was to verify the effect of pig slurry application with acidification and biochar on feed value, nitrogen use efficiency (NUE) of maize forage, and ammonia (NH3) emission. The four treatments were applied: 1) non-pig slurry (only water as a control, C), 2) only pig slurry application (P), 3) acidified pig slurry application (AP), 4) acidified pig slurry application with biochar (APB). The pig slurry and biochar were applied at a rate of 150 kg N ha-1 and 300 kg ha-1, respectively. The AP and APB treatments enhanced all feed values compared to C and P treatments. The NUE for plant N was significantly increased 92.1% by AP and APB treatment, respectively, compared to the P treatment. On the other hand, feed values were not significantly different between AP and APB treatments. The acidification treatment with/without biochar significantly mitigated NH3 emission compared to the P treatment. The cumulative NH3 emission throughout the period of measurement decreased by 71.4% and 74.8% in the AP and APB treatments. Also, APB treatment reduced ammonia emission by 11.9% compared to AP treatment. The present study clearly showed that acidification and biochar can reduce ammonia emission from pig slurry application, and pig slurry application with acidification and biochar exhibited potential effects in feed value, NUE, and reducing N losses from pig slurry application through reduction of NH3 emission.

Novel eco-friendly adsorbents were prepared through pyrolysis and acid activation of raw almond leaf (RAL) to form almond leaf biochar (ALB) and chemically activated almond leaf biochar (CAL), respectively. The prepared adsorbents were characterized using TGA, FTIR, SEM–EDX, BET and XRD techniques and their physicochemical properties investigated. RAL, ALB and CAL were utilized for adsorption of BPB dye from aqueous solution using batch technique under optimum conditions. The optimum dye adsorbed by RAL, ALB and CAL were 92.83, 93.21 and 94.89%, respectively at pH 3, dye initial conc. (100 mg/L), adsorbent dose (0.04 g/25 mL), 60 min contact time and 301 K adsorption temperature. Although, Langmuir maximum monolayer adsorption capacities were found to be 365.36, 535.62 and 730.46 mg/g for RAL, ALB and CAL, respectively, but isotherm conformed to Freundlich model. Kinetic study confirmed suitability of pseudo-second-order model with rate constant 9.33 × 10–4, 9.91 × 10–4 and 12.60 × 10−4 g mg−1 min−1 for RAL, ALB and CAL, respectively. Negative values of thermodynamic parameters (ΔG and ΔH) established sequestration process to be spontaneous and exothermic. RAL, ALB and CAL were discovered to be highly efficient adsorbents that could be used in place of expensive commercial adsorbents.

Empty fruit bunch (EFB) char was used to remove NOx and odorous substances. The physicochemical properties of the EFB chars were altered by steam or KOH treatments. The Brunauer-Emmett-Teller surface area and porosity were measured to determine the properties of the modified EFB chars. The deNOx and adsorption test for hydrogen sulphide and acetaldehyde were performed to determine the feasibility of the modified EFB chars. The KOH-treated EFB (KEFB) char revealed higher deNOx efficiency than with commercial activated carbon. The Cu-impregnated EFB char also had high deNOx efficiency at temperatures higher than 150°C. The KEFB char showed the highest hydrogen sulphide and acetaldehyde adsorption ability, followed by the steam-treated EFB char and untreated EFB char. Moreover, the product prepared by sulfonation of EFB char showed excellent performance for esterification of palm fatty acid distillate for biodiesel production.

Biochar obtained from the thermal conversion of biomass has high potential as a substitute material for activated carbon and other carbon-based materials because it is economical, environmentally friendly, and carbon-neutral. The physicochemical properties of biochar can also be controlled by a range of activation methods such as physical, chemical, and hydrothermal treatments. Activated biochar can be used as a catalyst for the catalytic pyrolysis of a biomass and as an absorbent for the removal of heavy metal ions and atmospheric pollutants. The applications of biochar are also expanding not only as a key component in producing energy storage materials, such as supercapacitors, lithium ion batteries, and fuel cells, but also in carbon capture and storage. This paper reviews the recent progress on the activation of biochar and its diverse present and future applications.

Emission reduction of CH4 (methane gas) from rice paddy soil is a very important measure for climate change mitigation in agricultural sector. In this study, we investigated the changes in crop yield and CH4 emissions in response to application of biochar and fertilizers. The experimental site is located in Hwasung, Kyunggido and experimental design is the split-plot method with three replicates. Treatments included rice straw (RS) and biochar (BC) amendments nested with the conventional NPK fertilizer (NPK) and slow release fertilizer (SRF). Control was also prepared with the soil with the conventional NPK fertilization with no amendment. Measurement of CH4 emission was conducted during the growing season of 2014 using a dynamic chamber method. The results showed that application of rice straw increased daily CH4 emission rate by 15%, while application of biochar reduced daily CH4 emission rate by 38%. When we combined biochar application with slow release fertilizer, CH4 emission was reduced by 45%. Further, the crop yield was also increased in all treatments compared with the control except for the treatment of rice straw application with slow release fertilizer. Overall results imply that biochar amendment to agricultural soil can be an effective strategy to decrease annual CH4 emission with no reduction in crop yield.

Biochar amendment to agricultural soil is regarded as a promising option to mitigateclimate change and enhance soil quality. It could sequester more carbon within the soil systemand increase plant yield by changing soil physicochemical characteristics. However, sustainableuse of biochar requires comprehensive environmental assessment. In this sense, it is important tomeasure additional greenhouse gas emission from soils after biochar addition. We investigatedemissions of CO2, N2O, and CH4from incubated soils collected from rice paddy and cultivatedgrassland after amendment of 3% biochar(wt.) produced from rice chaff. During incubation,soils were exposed to three wet-dry cycles ranging from 5~~85% soil gravimetric water content(WC) to investigate the changes in effect of biochar when influenced by different water levels. TheCO2emission was reduced in biochar treatment compared to the control at WC of 30~~70% bothin rice paddy and grassland soils. This indicates that biochar could function as a stabilizer for soilorganic carbon and it can be effective in carbon sequestration. The N2O emission was alsoreduced from the grassland soil treated with biochar when WC was greater than 30% because thebiochar treated soils had lower denitrification due to better aeration. In the rice paddy soil,biochar addition resulted in decrease in N2O emission when WC was greater than 70%, while anincrease was noted when WC was between 30~~70%. This increase might be related to the factthat available nutrients on biochar surface stimulated existing nitrifying bacterial community,resulting in higher N2O emission. Overall results imply that biochar amendment to agriculturalsoil can stabilize soil carbon from fast decomposition although attention should be paid toadditional N2O emission when biochar addition is combined with the application of nitrogenfertilizer.

The present study set out to investigate the adsorption of Cd(II) ions in an aqueous solution by using Peanut Husk Biochar (PHB). An FT-IR analysis revealed that the PHB contained carboxylic and carbonyl groups, O-H carboxylic acids, and bonded-OH groups, such that it could easily adsorb heavy metals. The adsorption of Cd(II) using PHB proved to be a better fit to the Langmuir isotherm than to the Freundlich isotherm. The maximum Langmuir adsorption capacity was 33.89 mg/g for Cd(II). The negative value of ΔGo confirm that the process whereby Cd(II) is adsorbed onto PHB is feasible and spontaneous in nature. In addition, the value of ΔGo increase with the temperature, suggesting that a lower temperature is more favorable to the adsorption process. The negative value of ΔHo indicates that the adsorption phenomenon is exothermic while the negative value of ΔSo suggests that the process is enthalpy-driven. As an alternative to commercial activated carbon, PHB could be used as a low-cost and environmentally friendly adsorbent for removing Cd(II) from aqueous solutions.

바이오차는 바이오매스를 고온에서 열분해하여 생성되는 탄화물로써, 공기 중 이산화탄소가 바이오매스를 거쳐 탄소 형태로 바이오차로 전환된 것을 저장할 경우, 지구 탄소 사이클의 일부를 고정하는 효과가 있다. 이처럼 저감할 수 있는 온실가스의 양을 이산화탄소로 환산할 경우, 연간 1.0~1.8Gt CO2에 달한다고 보고된 바있다. IEA는 2050년까지 세계 전력 소비량의 7.5%를 바이오에너지로 공급하겠다는 로드맵을 수립한 바 있다. 바이오차는 탄소로 구성된 고체물질로 다양한 분야에 활용될 수 있는데 본 연구에서는 매년 전정되어지는 과수 전정지와 도정과정에서 나오는 왕겨 등의 농업부산물, 가지치기나 간벌재 등의 임업부산물을 바이오차로 제조하는 방법에 대하여 연구하였다. 이를 이용해서 수질정화, 공기정화, 캐퍼시터 등에 활용할 수 있는데 이를 위해서는 활성화 단계를 거쳐 활성탄을 제조할 필요가 있다. 본 연구에서는 다양한 바이오매스 유래의 바이오차를 이용하여 비표면적이 넓은 활성탄 제조방법에 대해 연구하였다.