Advanced Review on Soil Microbiology and Fertility of Soils

    Mechanization in agriculture & Conserving of the resources, Vol. 67 (2023), Issue 1, pg(s) 27-31

    Soil microbiology is highly linked with the microorganisms and their particular activities regarding the growth of plants and yield while taking a part of the nitrogen cycle which is an important component in the providing of nutrients for the growth of plants. In the case of atmospheric nitrogen fixation, organic matter decomposition and releasing of some bio-chemical enzymes are the important factors regarding the growth of plants and roots. In generally, the microorganisms are categorized into a few of specific groups while considering their biological features and behaviors such as bacteria, viruses, fungus and algae. When considering the main role of microorganisms can do in the soil is the increasing of soil fertility while improving the soil structure, increasing the plant tolerance and providing of a self protection against the diseases of plants. According to the agricultural practices, the great diversity of microorganisms plays a few of important roles in the maintaining of the equilibrium of the soil and plant including the top soil which provides habitations for a large number of microbial communities.


    Comparison of the Precision of Dry Sieve Analysis versus Wet Sieve Analysis for Some Selected Natural Clay Varieties

    Machines. Technologies. Materials., Vol. 14 (2020), Issue 7, pg(s) 262-267

    Clay is a specific soil type that composed with relatively finer particles usually less than 0.002mm according to most of standard definitions including the behaviours of cohesive and the clay particles may have different sizes less than 0.002mm and most of occasions the clay bulk is contaminated with some more coarse particles such as sand and silt even though those particles are comprised in a same deposit or a same massive body. Most of clay varieties are frequently condign in the advanced technological uses. Therefore, the investigation of the particle sizes of some of clay and categorization are important tasks in the selection of a clay type for some particular technological application. The well known methods for the grain size analysis are the wet sieve analysis and dry sieve analysis in order for cohesive soils and non-cohesive soils as usual. In the existing study, there were anticipated to compare the accuracy of dry sieve analysis results with the wet sieve analysis results of three different selected clay verities in Sri Lanka. As the experiential works those clay samples were separately analyzed using a sieve range of 2mm- 0.037mm and pan (<0.037mm) using dry sieve method. Also those clay types were wet sieve analyzed with respect to the sieve size of 0.075mm. According to dry sieve analysis results the finer portions (<0.075mm) were obtained as ~17%, ~6% and ~16% from clay 1, clay 2 and clay 3. The results of wet sieve analysis showed ~60%, ~37% and ~72% of finer portions (<0.075mm) in clay 1, clay 2 and clay 3 while the average grain sizes (D50) of them were 0.25mm, 0.27mm and 0.19mm. When comparing of those results the minimum deviation between wet sieve analysis result and dry sieve analysis result was found from clay 2 which is having maximum average grain size (D50) while the maximum deviation was observing from clay 3 which is having minimum average grain size (D50).


    Characterization of Sri Lankan brick clays for more advanced industrial uses

    Machines. Technologies. Materials., Vol. 14 (2020), Issue 4, pg(s) 181-185

    Brick clay is a well known type of clay which is available at various locations in world and the name was realized because of the constantly usages in the industry of brick manufacturing that based on the condign characteristic with the necessitate features for the bricks. The investigations of the fundamental and advanced physic-chemical characteristics of a type of Sri Lankan brick clay and bespeaking of the more advanced industrial uses of such clays are the ultimate realities of the existing study. The collected clay samples from a particular location were fundamentally characterized by testing the natural moisture content, grain size distribution, acidity of raw clay samples and the water absorption, bulk density, porosity and mechanical strengths of prepared bricks under 8000C using such clay In addition that those clay samples were characterized using X-ray fluorescence (XRF) spectrophotometer, Fourier transform infrared (FT-IR) spectrophotometer and X-ray diffraction (XRD) spectrophotometer. As the retributions of those analyses, mainly observed 6.57 of PH, uniformly graded grain size distribution, 37.36% clay and silt portion according to the weight and 21.45% natural moisture content from raw clay samples and 19.88% water absorption, 3.15 gcm-3of bulk density, 62.70% of porosity, 17.25MPa compressive strength, 0.31MPa splitting tensile strength from prepared bricks. The compositional analysis results showed 84% of Fe content with trace amounts of Ti, Ba and Ca, presence of calcite, quartz and more Fe minerals while lacking of any hazardous elements or compounds such as the heavy metals. By considering the characters of brick clay, it is possible to recommend this clay for the applications of water treatments, ceramic manufacturing, refractory material and sorption (adsorber) material for removal of metals.


    Monitoring of the quality of ambient air using high volume air sampler

    Science. Business. Society., Vol. 5 (2020), Issue 2, pg(s) 51-55

    The quality of ambient air is a noticeable demonstration because the ambient air plays a cardinal preface on the human activities and most of environmental processes. The monitoring of the quality of air is an important part of the pollution control because the ambient air was confirmed as an affected branch on the earth from both anthropogenic activities and natural phenomena. In the existing investigation, there were expected to test the selected important air quality parameters of the ambient air at around the Peradeniya region in Sri Lanka which is known as relatively populous region with the traffic. The ambient air samples were collected through a glass fiber filter paper which was attached to the high volume air sampler and both PM10 concentration and concentration total suspended particles (TSP) of the ambient air were determined using weight differences of air collection bottle and filter paper. Beside of that the lead (Pb) concentrations and NOX concentrations of the ambient air were investigated using hot acid extraction method while having the contribution of atomic absorption spectrometer (AAS) and of absorbing method in to a liquid with the aid of UV- visible spectrometer. As the results, there were obtained 0.0141 ppm of PM10 concentration, 0.0214 ppm of total suspended particles (TSP) concentration, 0.151 μg/m3 of NOX concentration and 0.015μg Pb/ m3 of lead (Pb) concentration of the ambient air at around the Peradeniya region at that moment. When comparing of those results with the air quality standards and norms, it was identified the non hazardous atmosphere at the selected region at that occasion.


    Mineralogical characterization of different clay varieties on behalf of advanced industrial handling

    Machines. Technologies. Materials., Vol. 14 (2020), Issue 3, pg(s) 132-136

    Clay is a group of minerals that which is more industrial demanded material because of the specific strengths of some components of such clays in the fulfilments of some industrial and technological needs. The chemical composition and other important properties of clays are depended on the origin, location and some other environmental factors. The industrial applications might be varied upon the mineralogy of some of clay. In the existing research, three different types of clay were selected as the materials that namely as anthill clay, brick clay and roof tile clay. The selected types of clay samples were collected from three different regions in Sri Lanka. The collected clay samples were characterized using X-ray fluorescence (XRF) spectrophotometer, Fourier transform infrared (FT-IR) spectrophotometer and optical microscope. According to the investigation results, there were observed the presence of Fe as the most abundant element in all of clays at least 75%, large amounts of kaolinite in three clay types, intermediate amount of quartz and trace amounts of rutile in three clay types. In addition that it is possible to present muscovite in brick clays as a trace mineral and some trace amounts of Fe minerals such as glauconite and marcsite in three clay types. When comparing of the mineralogy of such clays mainly those clays are possible to be further developed as the adsorption materials (adsorber) for the recovering of metals from waste water and polluted air and a recovery material to remove some unnecessary components in chemical processes.