Abstract: Organic cultivation of crops is gaining importance consumer awareness towards pesticide residue free foodstuffs is increasing globally. This is also because of high costs of synthetic fertilizers and pesticides, making the conventional farming non-remunerative. In India, organic manures (such as vermicompost) are an important input in organic agriculture. Though vermicompost obtained through earthworm and microbe-mediated processes is known to comprise most of the crop nutrients, but they are in small amounts thus necessitating enrichment of nutrients so that crop nourishment is complete. Another characteristic of organic manures is that the pest infestations are kept under check due to induced resistance put up by the crop plants. In the present investigation, deoiled neem cake containing azadirachtin, copper ore tailings (COT), a source of micro-nutrients and microbial consortia were added for enrichment of vermicompost. Neem cake is a by-product obtained during the process of oil extraction from neem plant seeds. Three enriched vermicompost blends were prepared using vermicompost (at 70, 65 and 60%), deoiled neem cake (25, 30 and 35%), microbial consortia and COTwastes (5%). Enriched vermicompost was thoroughly mixed, moistened (25+5%), packed and incubated for 15 days at room temperature. In the crop response studies, the field trials on chili (Capsicum annum var. longum) and soybean, (Glycine max cv JS 335) were conducted during Kharif 2015 at the Main Agricultural Research Station, UAS, Dharwad-Karnataka, India. The vermicompost blend enriched with neem cake (known to possess higher amounts of nutrients) and vermicompost were applied to the crops and at two dosages and at two intervals of crop cycle (at sowing and 30 days after sowing) as per the treatment plan along with 50% recommended dose of fertilizer (RDF). 10 plants selected randomly in each plot were studied for pest density and plant damage. At maturity, crops were harvested, and the yields were recorded as per the treatments, and the data were analyzed using appropriate statistical tools and procedures. In the crops, chili and soybean, crop nourishment with neem enriched vermicompost reduced insect density and plant damage significantly compared to other treatments. These treatments registered as much yield (16.7 to 19.9 q/ha) as that realized in conventional chemical control (18.2 q/ha) in soybean, while 72 to 77 q/ha of green chili was harvested in the same treatments, being comparable to the chemical control (74 q/ha). The yield superiority of the treatments was of the order neem enriched vermicompost>conventional chemical control>neem cake>vermicompost>untreated control. The significant features of the result are that it reduces use of inorganic manures by 50% and synthetic chemical insecticides by 100%.
Abstract: Soil organic matter (SOM) plays an important role in maintaining soil productivity and accounting for the promotion of biological diversity. The main components of the SOM are the humic substances which can be fractionated according to its solubility in humic acid (HA), fulvic acids (FA) and humin (HU). The determination of the chemical properties of organic matter as well as its interaction with metallic species is an important tool for understanding the structure of the humic fractions. Fluorescence spectroscopy has been studied as a source of information about what is happening at the molecular level in these compounds. Specially, soils of Amazon region are an important ecosystem of the planet. The aim of this study is to understand the molecular and structural composition of HA samples from Spodosol of Amazonia using the fluorescence Emission-Excitation Matrix (EEM) and Time Resolved Fluorescence Spectroscopy (TRFS). The results showed that the samples of HA showed two fluorescent components; one has a more complex structure and the other one has a simpler structure, which was also seen in TRFS through the evaluation of each sample lifetime. Thus, studies of this nature become important because it aims to evaluate the molecular and structural characteristics of the humic fractions in the region that is considered as one of the most important regions in the world, the Amazon.
Abstract: Forward Osmosis (FO) polyamide thin-film composite
membranes have been prepared by interfacial polymerization using
commercial UF polyethersulfoneas membrane support. Different
interfacial polymerization times (10s, 30s and 60s) in the organic
solution containing trimesoyl chloride (TMC) at constant m-phenylenediamine
(MPD) concentration (2% w/v) were studied. The
synthesized polyamide membranes then tested for treatment of
natural organic matter (NOM) and compared to commercial Cellulose
TriAcetate (CTA) membrane. It was found that membrane prepared
with higher reaction time (30s and 60s) exhibited better membrane
performance (flux and humic acid removal) over commercial CTA
membrane.
Abstract: Humic acids (HA) were produced by a Trichoderma
viride strain under submerged fermentation in a medium based on the
oil palm empty fruit bunch (EFB) and the main variables of the
process were optimized by using response surface methodology. A
temperature of 40°C and concentrations of 50g/L EFB, 5.7g/L potato
peptone and 0.11g/L (NH4)2SO4 were the optimum levels of the
variables that maximize the HA production, within the
physicochemical and biological limits of the process. The optimized
conditions led to an experimental HA concentration of 428.4±17.5
mg/L, which validated the prediction from the statistical model of
412.0mg/L. This optimization increased about 7–fold the HA
production previously reported in the literature. Additionally, the
time profiles of HA production and fungal growth confirmed our
previous findings that HA production preferably occurs during fungal
sporulation. The present study demonstrated that T. viride
successfully produced HA via the submerged fermentation of EFB
and the process parameters were successfully optimized using a
statistics-based response surface model. To the best of our
knowledge, the present work is the first report on the optimization of
HA production from EFB by a biotechnological process, whose
feasibility was only pointed out in previous works.
Abstract: The increments of aromatic structures are widely used to monitor the degree of humification. Compost derived from mix manures mixed with agricultural wastes was studied. The compost collected at day 0, 7, 14, 21, 28, 35, 49, 77, 91, 105, and 119 was divided into 3 stages, initial stage at day 0, thermophilic stage during day 1-48, and mature stage during day 49-119. The change of highest absorptions at wavelength range between 210-235 nm during day 0- 49 implied that small molecules such as nitrates and carboxylic occurred faster than the aromatic molecules that were found at wavelength around 280 nm. The ratio of electron-transfer band at wavelength 253 nm by the benzonoid band at wavelength 230 nm (E253/E230) also gradually increased during the fermenting period indicating the presence of O-containing functional groups. This was in agreement with the shift change from aliphatic to aromatic structures as shown by the relationship with C/N and H/C ratios (r = - 0.631 and -0.717, p< 0.05) since both were decreasing. Although the amounts of humic acid (HA) were not different much during the humification process, the UV spectral deconvolution showed better qualitative characteristics to help in determining the compost quality. From this study, the compost should be used at day 49 and should not be kept longer than 3 months otherwise the quality of HA would decline regardless of the amounts of HA that might be rising. This implied that other processes, such as mineralization had an influence on the humification process changing HA-s structure and its qualities.
Abstract: Global temperature had increased by about 0.5oC over
the past century, increasing temperature leads to a loss or a decrease
of soil organic matter (SOM). Whereas soil organic matter in many
tropical soils is less stable than that of temperate soils, and it will be
easily affected by climate change. Therefore, conservation of soil
organic matter is urgent issue nowadays. This paper presents the
effect of different doses (5%, 15%) of Ca-type zeolite in conjunction
with organic manure, applied to soil samples from Philippines,
Paraguay and Japan, on the decomposition resistance of soil organic
matter under high temperature. Results showed that a remain or
slightly increase the C/N ratio of soil. There are an increase in
percent of humic acid (PQ) that extracted with Na4P2O7. A decrease
of percent of free humus (fH) after incubation was determined. A
larger the relative color intensity (RF) value and a lower the color
coefficient (6logK) value following increasing zeolite rates leading
to a higher degrees of humification. The increase in the aromatic
condensation of humic acid (HA) after incubation, as indicates by the
decrease of H/C and O/C ratios of HA. This finding indicates that the
use of zeolite could be beneficial with respect to SOM conservation
under global warming condition.
Abstract: Humic acids (HAs) have been shown to activate some
ion uptakes along with stimulating the lateral roots at effective
concentration of micronutrients. However, the effects of HA on ion
adsorption by plant roots are not easily explainable due to the
varieties of HAs that differ from origins. Therefore, this study was
aimed to investigate the effect of various concentrations of HA
obtained from the compost derived from mix manures and some
agricultural wastes on the growth of eggplant seedlings (Solanum
melongena L. cv. Chao Praya) in tissue cultures at low nutrient level.
Egg plant seeds were surfaced sterilized and germinated in ½
Murashige and Skoog medium (MS) without HA added or in ¼ MS
supplemented with 0, 25, 50, 75 and 100 ppm of HAs. Then, they
were cultured for 4 weeks under the controlled environment. The
results showed that seedlings grown on ¼MS supplemented with
HAs at the concentration of 25 and 50 ppm had the average plant
heights (2.49 and 2.28 cm, respectively) higher than the other
treatments. Both treatments also significantly showed the maximum
average fresh and dry weights (p
Abstract: The purpose of this study is to investigate the chemical
degradation of the organophosphorus pesticide of parathion and
carbamate insecticide of methomyl in the aqueous phase through
Fenton process. With the employment of batch Fenton process, the
degradation of the two selected pesticides at different pH, initial
concentration, humic acid concentration, and Fenton reagent dosages
was explored. The Fenton process was found effective to degrade
parathion and methomyl. The optimal dosage of Fenton reagents (i.e.,
molar concentration ratio of H2O2 to Fe2+) at pH 7 for parathion
degradation was equal to 3, which resulted in 50% removal of
parathion. Similarly, the optimal dosage for methomyl degradation
was 1, resulting in 80% removal of methomyl. This study also found
that the presence of humic substances has enhanced pesticide
degradation by Fenton process significantly. The mass spectroscopy
results showed that the hydroxyl free radical may attack the single
bonds with least energy of investigated pesticides to form smaller
molecules which is more easily to degrade either through
physio-chemical or bilolgical processes.
Abstract: The present work deals with the stabilisation of
organic clay using hydrated lime. Artificial organic clays were
prepared by adding kaolin and different humic acid contents. Results
given by physical testing show that the presence of humic acid has a
drawback effect on the untreated organic clay. The decrease in
specific gravity value was accompanied by a decrease in dry density
and plasticity of clay at higher humic acid contents. Significant
increase in shear strength at 7 days of curing period is observed in the
lime-treated samples up to 5% lime content. However shear strength
of lime-treated organic clay decreases at longer curing periods. The
results given by laboratory testing is further verified by
microstructure analysis. Based on the results obtained in this study, it
can be concluded that the presence of more than 1.5% humic acid
reduces significantly the efficiency of lime stabilization in organic
clays.
Abstract: For stricter drinking water regulations in the future, reducing the humic acid and disinfection byproducts in raw water, namely, trihalomethanes (THMs) and haloacetic acids (HAAs) is worthy for research. To investigate the removal of waterborne organic material using a lab-scale of bio-activated carbon filter under different EBCT, the concentrations of humic acid prepared were 0.01, 0.03, 0.06, 0.12, 0.17, 0.23, and 0.29 mg/L. Then we conducted experiments using a pilot plant with in-field of the serially connected bio-activated carbon filters and hollow fiber membrane processes employed in traditional water purification plants. Results showed under low TOC conditions of humic acid in influent (0.69 to 1.03 mg TOC/L) with an EBCT of 30 min, 40 min, and 50 min, TOC removal rates increases with greater EBCT, attaining about 39 % removal rate. The removal rate of THMs and HAAs by BACF was 54.8 % and 89.0 %, respectively.
Abstract: For more than 120 years, gold mining formed the
backbone the South Africa-s economy. The consequence of mine
closure was observed in large-scale land degradation and widespread
pollution of surface water and groundwater. This paper investigates
the feasibility of using natural zeolite in removing heavy metals
contaminating the Wonderfonteinspruit Catchment Area (WCA), a
water stream with high levels of heavy metals and radionuclide
pollution. Batch experiments were conducted to study the adsorption
behavior of natural zeolite with respect to Fe2+, Mn2+, Ni2+, and Zn2+.
The data was analysed using the Langmuir and Freudlich isotherms.
Langmuir was found to correlate the adsorption of Fe2+, Mn2+, Ni2+,
and Zn2+ better, with the adsorption capacity of 11.9 mg/g, 1.2 mg/g,
1.3 mg/g, and 14.7 mg/g, respectively. Two kinetic models namely,
pseudo-first order and pseudo second order were also tested to fit the
data. Pseudo-second order equation was found to be the best fit for
the adsorption of heavy metals by natural zeolite. Zeolite
functionalization with humic acid increased its uptake ability.