Microbial remediation of cadmium-contaminated soils and its mechanisms: a review / 生物工程学报

Excessive levels of cadmium (Cd) in soil exert serious negative impacts on soil ecosystems. Microorganisms are a common component of soil and show great potential for mitigating soil Cd. This review summarizes the application and remediation mechanisms of microorganisms, microbial-plants, and microbial-biochar in Cd-contaminated soil. Microorganisms such as Bacillus, Acinetobacter, Pseudomonas, and arbuscular mycorrhizal fungi (AMF) can change the biological validity of Cd through adsorption, mineralization, precipitation and dissolution. Different factors such as pH, temperature, biomass, concentration, and duration have significant effects on Cd bioavailability by microorganisms. Pseudomonas, Burkholderia, and Flavobacterium can promote the uptake of Cd2+ by hyperaccumulator through promotion and activation. Biochar, a soil amendment, possesses unique physicochemical properties and could act as a shelter for microorganisms in agriculture. The use of combined microbial-biochar can further stabilize Cd compared to using biochar alone.

Pyrolysis of Sewage Sludge: Physical, Chemical, Morphological and Mineralogical Transformations

Abstract The sewage sludge (SS) use in agriculture has been limited by the Brazilian legislation to a few situations, mainly as a precautionary measure due to inorganic pollutants and pathogens. Thus, a large amount of SS has been accumulated in landfills, with no prospect of use, generating great concern for governments and society. Thermal treatment via pyrolysis has stood out as an option for SS recycling, transforming it into a carbon-rich product known as SS biochar (SSB). Biochar from SS showed good potential to be used for agricultural and environmental purposes. The present study aimed to evaluate the influence of pyrolysis at 300°C on the physical, chemical, morphological and mineralogical characteristics of SSB. In general, pyrolysis increased total carbon, total nitrogen, macro and micronutrient contents, except potassium. Pyrolysis also increased heavy metals (HMs) concentration in SSB. However, HMs values remained below the maximum limits allowed according to the legislation on SS agricultural use. X-ray analysis showed that both SS and SSB present silica (SiO2) as the main mineral. Pyrolysis also increased the SS surface area (SA) and porosity. In general, results of the present study prove showed that pyrolysis is a technological alternative to enable SS use as a sustainable input in agriculture.

Estudo de propriedades físico-químicas na avaliação da adsorção em biocarvão produzido com folhas de amendoeira-da-praia / Study of physico-chemical properties in the evaluation of adsorption in biochar produced from leaves of amendoeira-da-praia

RESUMO Este estudo avaliou as propriedades físico-químicas envolvidas no processo de adsorção para subsidiar o potencial uso de biocarvão produzido com folhas secas de amendoeira-da-praia, Terminalia catappa, como remediador em águas contaminadas com metais. O biocarvão utilizado foi produzido por conversão à baixa temperatura e caracterizado por apresentar bandas de O-H, CH2, C-O e C-O-C; teores de 48,8% de carbono, 46,6% de oxigênio, 3,3% de hidrogênio e demais entre enxofre e nitrogênio; presença de macroporos e passado em peneira (100 mesh). Para o estudo, preparou-se um coquetel de radiotraçadores (Co-57, Mn-54 e Zn-65), que foi adicionado à água deionizada e massas de biocarvão com o objetivo de obter parâmetros tais como pH, tempo de equilíbrio e capacidade de adsorção por meio das isotermas de Langmuir e Freundlich. O detector de Germânio Hiperpuro foi utilizado para quantificar as atividades dos radiotraçadores por meio da técnica de espectroscopia gama para geração e tratamento de dados. Os resultados obtidos mostraram aumento na adsorção do pH 3,8 em diante e tempo de equilíbrio de 30 minutos ou mais. As isotermas de Langmuir e Freundlich construídas apresentaram bons ajustes, com valores de n maiores que 1, indicando preferência dos metais pelo material adsorvente. Além disso, levando-se em conta a competição pelos sítios ativos e a concentração inicial das soluções (ordem de picogramas), foram encontradas capacidades de adsorção de 1,273 ng.g-1 para o Zn-65, de 3.271 ng.g-1 para o Co-57 e de 9,026 ng.g-1 para o Mn-54.

ABSTRACT This study evaluated the physical-chemical properties of the adsorption process in biochar produced from dry leaves of beach-almond, Terminalia catappa, as a useful tool for remediation purposes in water contaminated with metals. The biochar was characterized by having: bands of O-H, CH2, C-O, and C-O-C; contents of 48.8% carbon, 46.6% oxygen, 3.3% hydrogen and the others between sulfur and nitrogen; the presence of macropores; and being sieved (100 mesh). Parameters such as pH, equilibrium time and adsorption capacity by the Langmuir and Freundlich isotherms were determined from experiments using a radiotracer cocktail (Co-57, Mn-54 and Zn-65) which was added to deionized water and a constants mass of biochar. The high-purity germanium detector (HPGe) was used to quantify the radiotracer activity by gamma spectroscopy. The results showed better adsorption from pH 3.8 and 30 minutes equilibrium time. The Langmuir and Freundlich isotherms had a good model fit, with n values higher than 1, and showed affinity between the metals and the biochar. The adsorption capacities of Zn-65, Co-57 and Mn-54 were 1.273 ng.g−1, 3.271 ng.g−1 and 9.026 ng.g−1, respectively.

Research progress on application of biochar in cultivation of agriculture and Chinese materia medica / 中国中药杂志

Biochar is a kind of solid material with high aromatization and rich in carbon, which is formed by pyrolysis of biomass at high temperature(250-700 ℃) under anoxic or hypoxic conditions. It has the characteristics of large specific surface area and rich pores. In recent years, as a good soil conditioner, biochar has gradually improved its advantages in improving soil rhizosphere micro ecological environment, promoting plant growth and development, and enhancing plant resistance, etc. It has been proved that biochar can affect the growth and development of plants by improving soil physical and chemical properties, adjusting microbial community structure, participating in the metabolic process in plants, and inducing plants to enhance resistance. This paper summarized the research progress of biochar application in agriculture and introduced the ecological effects and mechanism of biochar on plant seed germination, seedling growth, crop yield and stress resistance. Combined with the characteristics of Chinese materia medica, this paper expounds the application potential of biochar in improving the content of secondary metabolites of Chinese materia medica and alleviating continuous cropping obstacles of Chinese materia medica, etc. In the future, it is necessary to strengthen the research of biochar in the biosynthesis of secondary metabolites, allelopathy and heavy metal stress of medicinal plants, so as to provide reference for the application of biochar in the cultivation of Chinese materia medica.

Biochar addition for enhanced cucumber fruit quality under deficit irrigation / Adição de biochar para melhorar a qualidade de frutos do pepino sob irrigação em déficit

In the recent years, biochar has been used as an organic soil amendment. Therefore, this study was undertaken in April 2016 to July 2017 to examine the effect of different biochar addition (BA) rates and deficit irrigation (DI) on quality characteristics of cucumber under greenhouse conditions over two consecutive growing seasons. The BA treatments were B0 (0-ton ha-1), B1 (10-ton ha-1and B2 (20-ton ha-1), while the DI treatments were 1.0 (W1), 0.60 (W2) and 0.40 (W3) of the reference evapotranspiration (ET0). The results obtained elaborated that the combination of B2W1 gave the maximum values of fruit weight (g), fruit water content (%), fruit dry biomass (g) and pH in the both seasons. On the other hand, W2 and W3 increased significantly titratable acidity (TA %) and total soluble solid (TSS %). It was possible to conclude that BA with DI might be a novel approach to improve both crop yield and fruit quality.

Nos últimos anos, o biochar tem sido utilizado como uma alteração do solo orgânico. Desta maneira, este estudo foi realizado entre os períodos de Abril de 2016 a Julho de 2017 para investigar o efeito de diferentes taxas de alteração de biochar e irrigação por déficit (DI) nas características de qualidade do pepino em casa de vegetação durante duas safras consecutivas. Os tratamentos BA foram B0 (0 ton ha-1), B1 (10 ton ha-1 e B2 (20 ton ha-1), juntamente com três lâminas de irrigação em déficit W1, W2 e W3 correspondentes 100%, 60% e 40% da ET0, respectivamente. Os resultados obtidos mostraram que a combinação de B2W1 forneceu os valores máximos de peso dos frutos (g), teor de água dos frutos (%), biomassa seca dos frutos (g) e pH nas duas safras. Por outro lado, W2 e W3 aumentaram significativamente a acidez titulável (TA%) e o sólido solúvel total (TSS%). Foi possível concluir que a alteração de biochar com DI pode ser uma nova abordagem para melhorar tanto a produtividade como a qualidade dos frutos.

Obtaining bioproducts by slow pyrolysis of coffee and cocoa husks as suitable candidates for being used as soil amendment and source of energy / Obtención de bioproductos por pirólisis lenta de cascarillas de café y cacao para su posible uso como fuentes de energía y fertilizantes / Obtenção de bioprodutos por pirólise lenta de cascas de café e cacau para possível uso como fontes de energia e fertilizantes

Abstract The agricultural economic policy of Cuba pretends to triplicate the crops of coffee and cocoa by 2021, a measure which will bring about both an increase in biomass waste and the need to find a proper method for its disposal. Slow pyrolysis process can transform lignocellulosic waste into added value products as biochar, bio-oil and gas. The present research evaluated the yield and the theoretical potential energy of co-products (bio-char, bio-oil, and gas) from coffee and cocoa seed husks using the pyrolysis process as a source of friendly and renewable energy. Results indicated that coffee husks are more suitable for the production of gas with a yield of 40.4%, while cocoa seed husks are better suited for the production of bio-oil, with a yield of 37.4%. For 2021 the theoretical energy potential estimated is 8291 MWh, equivalent to 716000 kg for the coffee husks, and 1384 MWh equivalent to 121000 kg for the cocoa seed husks. The bio-char characterization indicated high contents of carbon, calcium, potassium, nitrogen, and oxygen, which makes it a suitable candidate for being used as a soil amendment. The conversion of coffee and cocoa seed husks into added value products through slow pyrolysis process will help clean the environment, decrease the greenhouse effect, and will aid farmers in the rural populations by providing them with an additional source of income.

Resumen La política económica agrícola de Cuba pretende triplicar los cultivos de café y cacao para el año 2021, lo cual implica un aumento de residuos de biomasa y la necesidad de encontrar un uso adecuado para su eliminación. El proceso de pirólisis lenta permite convertir los residuos lignocelulósicos en productos de valor agregado como bio-carbón, bio-combustible y gas. En este trabajo se evaluó el rendimiento y el potencial energético teórico de estos co-productos como fuente de energía renovable. Las cascaras de café son más adecuadas para la producción de gas con un rendimiento del 40,4%, mientras que las de semilla de cacao para bio-combustible, con un rendimiento del 37,4%. Para el 2021, el potencial energético teórico estimado es de 8291 MWh, equivalente a 716000 kg para las cascaras de café; y de 1384 MWh equivalente a 121000 kg para las semillas de cacao. La caracterización del bio-carbón indicó altos contenidos de carbono, calcio, potasio, nitrógeno y oxígeno, lo que los convierte en un candidato adecuado para su uso como fertilizante del suelo. La conversión de estas biomasas en productos de valor agregado a través del proceso de pirólisis lenta contribuirá a mantener un ambiente limpio, reducir el efecto invernadero y ayudará a generar un ingreso adicional a los agricultores de las poblaciones rurales.

Resumo A política económica agrícola de Cuba visa triplicar as safras de café e cacau até 2021, o que significa um aumento nos resíduos de biomassa e a necessidade de encontrar usos adequados para sua eliminação. O processo de pirólise lenta permite converter lixo lignocelulósico em produtos de alto valor agregado, como bio-carvão, biocombustível e gás. No presente trabalho, avaliou-se o desempenho e o potencial energético teórico de co-produtos (bio-carvão, biocombustível e gás) do processo de pirólise lenta de casca de café e de cascas de sementes de cacau como fonte de energia renovável. As cascas de café são mais adequadas para a produção de gás com rendimento de 40,4%, enquanto que as cascas de sementes de cacau para biocombustível, com rendimento de 37,4%. Até 2021, o potencial energético teórico calculado é de 8291 MWh equivalente a 716000 kg para cascas de café e 1384 MWh equivalente a 121000 kg para cascas de sementes de cacau. A caracterização de bio-carvão indicou altos teores de carbono, cálcio, potássio, nitrogénio e compostos oxigenados, o que os torna candidatos ideais para uso como fertilizantes do solo. A conversão da casca do café e a casca das sementes de cacau em produtos de maior valor agregado, através do processo de pirólise lenta, ajudará a manter o um ambiente limpo, reduzirá o efeito estufa e contribuirá com renda adicional para os agricultores das populações rurais.

Corn (Zea mays L.) growth, nutrient uptake and soil fertility improvement of strongly acidic soil applied with biochar and animal manure

The effects of biochar and animal manure application on soil chemical properties, nutrient uptake, growth, andbiomass production of corn grown in strongly acidic soil were assessed in a pot experiment. The experimentwas laid out in randomized complete block design with the following treatments: (1) control; (2) 15 t chickenmanure (CM) ha−1; (3) 30 t CM ha−1; (4) 15 t carabao dung (CD) ha−1; (5) 30 t CD ha−1; (6) 15 t chickenmanure biochar (CMB) ha−1; (7) 30 t CMB ha−1; (8) 15 t carabao dung biochar (CDB) ha−1; and (9) 30 tCDB ha−1. Application of 30 t CM ha−1 significantly increased soil pH by 1.03-unit, total organic carbon,total N, and exchangeable K by 138%, 300%, and 955%, respectively, and a 108-fold increase in P, over thecontrol treatment. Similarly, the addition of CM at 15 t ha−1 significantly increased all soil chemical parametersgathered. Moreover, the addition of 15 t CM ha−1 increased plant height, shoot, and total biomass by 62%,161%, and 148% over the control treatment. Meanwhile, tissue N uptake of corn increased by 147% and 124%with the CM application at the rate of 15 t ha−1 and 30 t ha−1. Among organic materials evaluated, CM had themost superior influence on soil chemical properties, growth, biomass production, and plant nutrition.

Synthesis of enriched biochar as a vehicle for phosphorus in tropical soils

Phosphorus (P) is one of the nutrients that most limits agricultural productivity, especially in tropical soils. Enriched biochar has been proposed to increase the bioavailability of P and other nutrients in the soil. Thus, the objective of this study was to evaluate the availability of P in phosphate biochar (composed of biomass and soil) as a function of the triple superphosphate mixture before and after the pyrolysis process. We produced eight types of enriched biochar via pyrolysis by combining sandy or clayey soil with rice or coffee husk, and by adding triple superphosphate before or after pyrolysis. The heating of the phosphate fertilizer during the pyrolysis process resulted in a higher crystallinity of the phosphates, lower content of labile fractions of P and lower content of available P in phosphate biochars than when the superphosphate was added after pyrolysis. (AU)

Contrast effect of biochars and attapulgite clay on the adsorption and removal of cadmium ions from metal contaminated aqueous solution

Aim: To study the contrasting effect of adsorption and removal of cadmium ions using wheat straw biochar, rice straw biochar and attapulgite clay in contaminated aqueous solution. Methodology: Batch sorption experiment was carried out to investigate the parameters influencing the adsorption capacity such as pH, initial cadmium concentration, adsorbent dose and contact time. The physical and chemical characteristics of biochars and clay were studied and adsorption mechanism was analyzed by scanning electron microscopy, infrared spectroscopy, Brunauer-Emmett-Teller and X-ray diffraction, which indicated high adsorption and removal of Cd+2ions by wheat straw biochar was mainly due to the presence of surface carboxyl functional groups –OH, C-O, COOH that reacted Cd2+ions. Results: The adsorption effect of wheat straw biochar (WSB), rice straw biochar (RSB) and attapulgite (ATP) clay were compared. The results showed that adsorption isotherms were best fit to Langmui isotherm model. The adsorption kinetics study well matched with pseudo second order model and the maximum adsorption equilibrium of WSB, RSB and ATP reached to 100, 160, and 120 min, respectively. The results showed that adsorption rate was maximum at pH 6 with 0.1 g dose of adsorbent, 40 mg l-1 metal concentration, and contact time of 100 min at 30°C for WSB. The maximum percent removal of cadmium ions from aqueous solution was in the order WSB>ATP>RSB, 95%, 91% and 88%, respectively. Interpretation: The results explored that wheat straw biochar has high Cd2+adsorption rate and removal efficiency in contaminated water than others. Hence, the results explored that WSB is a potential, low-cost adsorbent and can be used as cadmium decontaminant in polluted water with no secondary pollution.

Mineralization and mobilization of biosolids phosphorus in soil: A concise review

Biosolids are the product of wastewater or municipal solid waste collected through sewerage treatment; theprocesses of obtaining the biosolids involve various treatment processes, which include digestion, thermalstabilization, thickening, dewatering, and drying, in order to obtain free pathogen granules. These processesundergone by wastewater in the treatment plant ultimately clean the wastewater and remove the solids whichare further treated to an acceptable standard for beneficial soil amendments. The application of biosolids areconsidered to improve soil organic matter, moisture content, and provided essential nutrients, such as nitrogenand phosphorus in arable land as potential plant nutrients supplements for crop optimum yield. Incubationstudies on the biosolids-amended soils have shown significant increases in soil phosphorus content beingreleased as plant available P in the soil, and therefore could be a good source of phosphorus in deficientnative phosphorus soil. Field-scale experiments on wheat are grown with sewage sludge have also shown yieldproduction comparable to mineral fertilizer-treated soils. This review is thereby aimed at explaining the conceptbehind the mineralization and mobilization of biosolids phosphorus in soil. In this review paper, an overviewof the method of preparations, origin, and sources, its application in agriculture and the environment, chemicalcomposition, the environmental risk, soil amendments potentials of the biosolid sand regulatory, and globalperspective of sewage sludge disposal all are reviewed. From the review, it was concluded that mineralizationand mobilization of biosolids phosphorus in soil have beneficial input to both environment and soil nutrientamendment. It is thereby recommended that more research studies should be carried out on the mineralizationand mobilization of another essential element, such as nitrogen and biochar although more research should bedone with respect to mineralization and mobilization of biosolids phosphorus in soil.

Effect of Shea Nut Shell Biochar on Root Knot Nematodes (Meloidogyne spp.) of Tomato (Solanum lycopersicum L.)

Effect of shea nut shell biochar on root knot nematodes and performance of tomato was investigated under nematode inoculated soils. Steam sterilized soil was admixed with biochar, which was later inoculated with 1000 second stage juveniles (J2) two weeks after transplanting. Tomato variety (Petomech-GH) was planted in potting medium of soil to biochar ratio of one part of biochar (250 g) is to one part of soil (1B1S), one part of biochar is to two parts of soil (1B2S), two parts of biochar is to one part of soil (2B1S), and no biochar application (control). Steam sterilized soil amended with biochar inoculated with 1000 second stage juveniles (J2). The result indicated that, biochar increased the pH of the soil, lessened the adverse effects of Meloidogyne spp., resulting in decline in galling and improvement in growth and yield of tomato. Increased biochar concentration resulted in decreased nematode gall formation on the roots of the tomato plant. Biochar amended soils resulted in lower egg masses. Increased biochar concentration resulted in decreased performance of tomato plant. Tomato plants treated with low biochar concentrations (1B2S and 1B1S) produced higher fruit numbers and weights, and plant biomass.

Use of Adsorbent Biochar from Pequi (Caryocar Brasiliense) Husks for the Removal of Commercial Formulation of Glyphosate from Aqueous Media

Abstract This study evaluated the capacity of adsorbent biochar derived from pequi husks to remove glyphosate (commercial formulation) in aqueous medium under three pH conditions (5.5, 7.0 and 8.0). This biochar presented a mean yield of 33.1% ± 2.66% and a high amount of surface particles of small dimensions endowing it with high surface area. The results showed that removal is proportional to pH increase in the range of 5.5 to 8.0. Adsorption assays performed at pH 7 and 8 fitted better to the Langmuir pseudo-first order kinetics model with fast adsorption in the first 15 to 30 minutes. The results for the acidic pH range fit none of the adopted models satisfactorily. The results obtained suggest that adsorbent can be used as an efficient and inexpensive alternative for the adsorption of glyphosate present in commercial formulations from aqueous matrices.

Nitrogen and phosphorus uptake efficiency in Indian mustard cultivated during three growth cycles in a copper contaminated soil treated with biochar / Eficiência de absorção de nitrogênio e fósforo em mostarda indiana cultivada por três ciclos sucessivos em um solo contaminado com cobre e tratado com biocarvão

ABSTRACT: Biochar has been used worldwide as an efficient soil amendment due to its beneficial interaction with soil particles and nutrients; however, studies on the effect of biochar on the availability of nutrients such as N and P in tropical soils are still missing. The objective of the study was to evaluate the effect of different types and doses of biochars on the concentration and uptake of N and P in Indian mustard plants (Brassica juncea L.) grown in a Cu contaminated soil during three successive growth cycles. The greenhouse experiment was set up as randomized block design in a 3x3 factorial scheme, with 3 types of biochars (coconut shell, orange bagasse and sewage sludge) and three rates of application (0, 30 and 60t ha-1), and 4 replicates. Biochar increased plant growth by approximately 30 to 224%; however, the orange bagasse biochar was the most effective. Biochar reduced plant N concentration in approximately 15-43%, regardless of the rate of application, indicating the need to carefully adjust N fertilization. In the last growth cycle, biochar from coconut shell and orange bagasse improved the N uptake efficiency suggesting a better amelioration effect with ageing in soil. Biochar did not affect P nutrition in Indian mustard to a great extent; however, it significantly decreased the N:P ratio in the plant.

RESUMO: O biocarvão tem sido usado mundialmente como um eficiente insumo agrícola devido à sua interação benéfica com as partículas e os nutrientes do solo. Contudo, seu efeito na disponibilidade de nutrientes como N e P em solos tropicais tem sido pouco investigado. O objetivo do estudo foi avaliar o efeito de diferentes tipos e doses de biocarvão na concentração e na eficiência de absorção de N e P em plantas de mostarda indiana (Brassica juncea L.) cultivadas em solo contaminado com cobre, em três ciclos sucessivos de cultivo. O estudo foi desenvolvido em delineamento de blocos casualizados, em esquema fatorial 3x3, em casa de vegetação, com três tipos de biocarvão (casca de coco, bagaço de laranja e lodo de esgoto) e três doses (0, 30 e 60t ha-1). Todos os biocarvões aumentaram o crescimento das plantas, com variação de 30 a 224%. No entanto, o biocarvão de bagaço de laranja foi o mais eficiente. A presença de biocarvão reduziu a concentração de N nas plantas em torno de 14 a 43%, independente da dose aplicada, indicando a necessidade de monitoramento mais cuidadoso da fertilização nitrogenada. Os biocarvões de casca de coco e bagaço de laranja melhoraram a eficiência da planta na absorção de N no terceiro ciclo de cultivo, indicando melhor efeito com o tempo de contato como o solo. O uso de biocarvão teve pouca influência na nutrição fosfatada na mostarda indiana, mas diminuiu significativamente a relação N:P.

Physicochemical Characteristics of Activated Biochar Derived from Different Sources

An experiment was carried out to study the characteristics of biochar made from rice husk, rice straw, Toria stover and bamboo leaves. Biochar was produced by slow pyrolysis system (300 –4000C). Locally available bio-wastes viz.rice husk, rice straw, toriastover and bamboo leaves were used as raw materials to produce chars. Two samples of feedstock each from 5 development blocks of Jorhat district of Assam were collected, dried and pyrolysed for production of char for their physicochemical properties. Per cent moisture and ash content, bulk density, particle density andporosity of biochars ranged from 3.26 to 4.91%, 3.70 to 24.97%, 0.178 to 0.729 g/cm3, 0.85 to 2.02 g/cm3 and 61.54 to 78.90%, respectively. Pore volume, particle size and specific surface area ranged from 0.83 to 1.15 ml, 310×147 to 350×209 ?m2 and 89.40 to 184.75 m2/g, whereas pH ,EC, CEC, total Carbon varied from 7.74 to 9.46, 0.272 to 1.005 dsm-1, 12.74 to16.68 c mol (p+)/kg and 36.63 to 49.424%, respectively. Porosity maintained significant and positive correlation with pore volume (0.715**) and specific surface area (0.614**). CEC had significant positive correlations with total C (0.583**), total N (0.587**), total K (0.443**) and IAN (0.766**).Percent total N, P, K, and S had their value ranged from 47.27 to 60.07, 0.017 to 0.032, 0.237 to 0.453 and 0.083 to 0.099; while, Ca and Mg, Fe, Zn, Cu and Iodine adsorption number ranged from 1.11 to 5.23 and 0.148 to 1.326 c mol (p+)/kg, 16.65 to 2.91, 30 to 162, 8.6 to 43 mg/kg and 186.64 to 489.77 mg/g of biochar

Effects of Biochar Amended Saline Soil on Growth and Some Metabolic Activities of Two Soybean Cultivars in Saudi Arabia

Application of biochar to soil additionally restores soil Carbon and nutrients lost from bioenergy cropping systems as a result of biomass harvesting. This study was carried out to investigate the effect of biochar amended saline soil on plant growth, leaf chlorophyll, soil mineral contents and some physiological parameters of two Soybean cultivars in Saudi Arabia. The obtained results showed that plant height, fresh and dry weight, chlorophyll a and b content of both varieties (Giza-111 and Clark) were inhibited in saline soil while enhanced in biochar one which derived from Pomegranate trees or biochar two which obtained from acacia trees. The highest value of carbohydrate and protein contents observed in Giza-111 with the compare to Clark cultivars under salinity conditions. It was concluded that soybean is a sensitive plant to salinity stress, but the extent of this sensitivity varies among cultivars. As a result, Giza-111 cultivar showed more capability to survive under salinity condition compared with another variety regarding of almost all plant parameter examined. Considering, biochar one was found more appropriate under salinity condition.

Component Analysis of Biochar Based on Near Infrared Spectroscopy Technology / 分析化学

A rapid quantitative component analysis method for biochar based on near infrared spectroscopy (NIRS) technology was established in this study. Near infrared spectra of 163 samples in 10000-3800 cm-1 (1000-2632 nm) range were collected, and the contents of fixed carbon (FC), volatile matter (VM) and ash of samples were analyzed. A partial least square(PLS) model for FC,VM and Ash was established in the optimized model spectral ranges. The factors were optimized and the raw spectra were pretreated by multiple scatter correction and second derivative(MSC+SD) method. Finally,the prediction performance of predictive model was evaluated. The results showed that the PLS model had a good prediction ability,and the predicted coefficient R2pof actual values vs prediction values for FC, VM and Ash were 0.9423,0.9517 and 0.9265, respectively. Root mean square errors of prediction(RMSEP) were 0.1074,0.1201 and 0.1243,and ratios of prediction to deviation(RPD) were 3.51,4.28 and 2.03,respectively. The PLS model has good accuracy and precision for both of FC and VM, and can be used as a quantitative method for FC and VM contents analysis. Nevertheless,PLS model needs to improve the precision for Ash analysis according to RPD value. The method provides a fast and effective technical means for the quantitative analysis of biochar components.

Efeito da aplicação de biocarvão, cama de frango e formulado NPK no estado nutricional foliar de laranjeira em terra mulata / Effect of biochar, poultry litter and NPK on the nutritional status leaf of orange on terra mulata

O cultivo de laranjeira em Terra Mulata tem apresentado limitações nutricionais sendo necessário o uso de adubos nas áreas agrícolas. A aplicação de biocarvão associado à outra fonte de nutrientes pode ser uma alternativa viável para aumentar a eficiência dos adubos e diminuir perdas nestas áreas. O objetivo deste trabalho foi avaliar o efeito do biocarvão, da cama de frango e do formulado NPK, no estado nutricional de laranjeiras Pera-Rio cultivadas em um Latossolo Amarelo distrófico com horizonte A antrópico (Terra Mulata). O estudo foi desenvolvido em uma propriedade rural de terra firme em Manacapuru (AM) em um delineamento de blocos casualizados com oito tratamentos utilizando biocarvão, cama de frango e formulado NPK (4-14-8) aplicados de maneira isolada e associados. Para avaliação foram retiradas duas amostras em períodos distintos de folhas para determinação do estado nutricional. Os adubos aplicados não aumentaram a eficiência na disponibilidade dos teores de N, P, Fe e Zn, ficando este último abaixo da faixa de teor adequado. Já para os teores de K, o adubo cama de frango e suas combinações aumentaram sua disponibilidade, e os maiores teores de Mg foram encontrados no tratamento controle.

Growing in orange on Terra Mulata has been submitted nutrient limitation requiring correction in agricultural areas. The application of biochar associated with another source of nutrients can be a viable alternative to increase the efficiency of fertilizers and reduce losses in the areas. The objective of this study was to evaluate the effect of biochar, poultry litter and NPK in the nutritional status of orange trees grown in an Oxisol with anthropogenic A horizon (Terra Mulata). The study was conducted in a rural property landfall in Manacapuru (AM) in a randomized block design with eight treatments using biochar, poultry litter and NPK (4-14-8) applied in isolation and associates. To review two samples were taken at different periods of sheets to determine the nutritional status. Fertilizers applied did not increase the efficiency in the availability of contents of N, P, Fe and Zn, being the latter below the range of suitable content. As for the K, compost chicken manure and their combinations increased their availability, and the highest levels of Mg were found in the control treatment.

Effect of Biochar on the Abundance of Soil Bacteria.

A pot experiment was conducted to study the effect of biochar on the abundance of soil bacteria and compare it with the source biomass. Seven different treatments and a control were used in the experimental set-up. Three different types of biomass were selected and three types of biochar were produced from them. Both the materials were applied to the soil at a rate of 5t/ha. All treatments were incubated for 30, 60 and 90 days. Cultural, microscopic and biochemical tests were carried out to identify the bacterial isolates in soils treated with biochar and its source biomass. Bacterial isolates identified in soil and in some of the biomasses before treatments were applied include Bacillus badius, Bacillus krulwichiae, Bacillus siralis, Bacillus sylvestris, Bacillus flexus, Aneurinibacillus aneurinilyticus and Bacillus thuringiensis while after incubation periods, seven new isolates were identified. This was true for the biomass treated soils where additional one to two isolates reappeared. Conversely, in the biochar treated soils, most of the isolates disappeared except Bacillus badius that survived in all soils till 90 days. Because of its tolerant nature, it was further investigated for cellulase enzyme activity. Interestingly, the isolate did not show any such activity. Conclusively, biochar application may exert negative effect on the distribution and proliferation of soil bacteria with possible effect on soil quality and crop production.

Tratamento de Resíduos de Serviços de Saúde pelo processo de pirólise / Health waste treatment by pyrolysis

O presente trabalho apresenta a avaliação técnica e ambiental de uma planta piloto de tratamento de Resíduos de Serviços de Saúde (RSS) por pirólise quanto à produtividade, ao consumo de combustível, ao rendimento gravimétrico do processo, às emissões atmosféricas, aos efluentes líquidos e ao produto carbonizado obtido. O processo apresentou valores para perda de massa entre 46,75 e 58,77%, para tempos de processamento variando entre 2 e 6 horas. A tecnologia empregada demonstrou maior segurança ambiental na terceira condição de operação testada, em relação às emissões de contaminantes para a atmosfera, levando-se em consideração o valor obtido na concentração de dioxinas e furanos de 0,0162 ng/Nm3. Nessa condição, a operação ocorreu com dois combustores, gás de pirólise sendo injetado no duto de alimentação de biomassa e com incremento de 15% no volume do fluxo de ar na zona de combustão dos cavacos, em mistura com o gás de pirólise. A solução proposta apresentou potencial para ser aplicada em municípios que enfrentam o gerenciamento adequado dos RSS como um desafio a ser transposto.

This work shows the technical and environmental evaluation of a pilot plant for treatment of health waste by pyrolysis, regarding its productivity, fuel consumption, weight loss in the process, atmospheric emissions, wastewater and the charcoal obtained. The process resulted in values of weight loss between 46,75 and 58,77%, for processing time ranged between 2 and 6 hours. The greatest environmental safety was obtained in the third tested operation condition, concerning atmospheric emissions of pollutants, as the concentration of dioxins and furans value obtained was 0,0162ng/Nm3. Two combustors were used in the operation, pyrolysis gas was injected in the biomass feed pipe, and the air flow volume was increased by 15% in the combustion zone of the wood chips, mixed with the pyrolysis gas. The proposed solution has shown great potential to be used in municipalities dealing with proper management of health waste as a challenge to be overcome.

Comparison of DNA extraction protocols for microbial communities from soil treated with biochar

Many studies have evaluated the effects of biochar application on soil structure and plant growth. However, there are very few studies describing the effect of biochar on native soil microbial communities. Microbial analysis of environmental samples requires accurate and reproducible methods for the extraction of DNA from samples. Because of the variety among microbial species and the strong adsorption of the phosphate backbone of the DNA molecule to biochar, extracting and purifying high quality microbial DNA from biochar-amended soil is not a trivial process and can be considerably more difficult than the extraction of DNA from other environmental samples. The aim of this study was to compare the relative efficacies of three commercial DNA extraction kits, the FastDNA® SPIN Kit for Soil (FD kit), the PowerSoil® DNA Isolation Kit (PS kit) and the ZR Soil Microbe DNA Kit MiniprepTM (ZR kit), for extracting microbial genomic DNA from sand treated with different types of biochar. The methods were evaluated by comparing the DNA yields and purity and by analysing the bacterial and fungal community profiles generated by PCR-DGGE. Our results showed that the PCR-DGGE profiles for bacterial and fungal communities were highly affected by the purity and yield of the different DNA extracts. Among the tested kits, the PS kit was the most efficient with respect to the amount and purity of recovered DNA and considering the complexity of the generated DGGE microbial fingerprint from the sand-biochar samples.