RESUMEN
Microalgae have been increasingly used to generate biofuel, thus a sustainable technique should be implemented to harvest the biomass to ensure its existence in the environment. Aspergillus niger was used as bio-flocculant to harvest microalgae from aquaculture wastewater via flocculation technique over a range of pH and mixing rate. The bio-flocculant showed ability to adapt at a wide range of pH from 3.0 to 9.0 and at a mixing rate of 100-150â¯rpm, producing a harvesting efficiency of higher than 90%. The treated water possessed low concentration of chlorophyll-a (0.3-0.6â¯mgâ¯L-1) and cell density (2â¯×â¯106-3â¯×â¯106â¯cell mL-1). These indicate that Aspergillus niger is a promising bio-flocculant to be used in harvesting microalgae, thus promoting the use of flocculation as a green technology in aquaculture wastewater treatment.
Asunto(s)
Chlorella , Microalgas , Acuicultura , Aspergillus niger , Biomasa , Floculación , Aguas Residuales , AguaRESUMEN
The natural coagulant Moringa oleifera lectin (MoL) as cationic protein is a promising candidate in coagulation process of water treatment plant. Introducing the gene encoding MoL into a host, Pichia pastoris, to secrete soluble recombinant protein is assessed in this study. Initial screening using PCR confirmed the insertion of MoL gene, and SDS-PAGE analysis detected the MoL protein at 8 kDa. Cultured optimization showed the highest MoL protein at 520 mg/L was observed at 28 °C for 144 h of culturing by induction in 1% methanol. Approximately, 0.40 mg/mL of recombinant MoL protein showed 95 ± 2% turbidity removal of 1% kaolin suspension. In 0.1% kaolin suspension, the concentration of MoL at 10 µg/mL exhibits the highest turbidity reduction at 68 ± 1%. Thus, recombinant MoL protein from P. pastoris is an effective coagulant for water treatment.
Asunto(s)
Caolín/aislamiento & purificación , Moringa oleifera/química , Lectinas de Plantas/genética , Contaminantes Químicos del Agua/aislamiento & purificación , Purificación del Agua/métodos , Clonación Molecular , Floculación/efectos de los fármacos , Expresión Génica , Humanos , Moringa oleifera/metabolismo , Nefelometría y Turbidimetría , Pichia/genética , Pichia/metabolismo , Lectinas de Plantas/biosíntesis , Lectinas de Plantas/química , Lectinas de Plantas/farmacología , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacología , Agua/químicaRESUMEN
Archaeological excavations carried out on 17 iron smelting workshops at the Sungai Batu Archaeological Complex have found the raw materials of iron industry (hematite, magnetite and geotite) with iron slag, tuyere, remains of furnace, and iron ingots. In order to obtain primary data related to the location of the raw materials of iron smelting obtained, the survey and mapping activities were carried out using geological maps and Sungai Petani maps around UiTM Merbok, Bukit Inas, Merbok, Batu 5 Village, Paya Suri Village and Ayer Nasi Hill, Semeling. The results of the iron ore survey were then subjected to scientific analysis to compare the mineral composition with the findings of iron ore at the iron smelting site. The results of X-Ray Fluorescence (XRF) analysis of iron ore for major elements reveal the elements silica oxide (SiO2), iron oxide (FeOâ), manganese oxide (MnO), calcium oxide (CaO), aluminum oxide (Al2O3) and titanium oxide (TiO2) as well as arsenic (As), Chlorine (Cl), copper (Cu), scandium (S), vanadium (V) and zinc (Zn) for trace elements clearly show the raw material of iron smelting in the Archaeological Complex Sungai Batu is from the same source. Based on the analysis of the raw materials of iron smelting to enable the iron smelting industry in the Archaeological Complex to take place is taken from a distance of 1-11 km from this complex.
RESUMEN
As a chronic disease, diabetes mellitus has emerged as a worldwide epidemic. The aim of this study is to classify diabetes disease by developing an intelligence system using machine learning techniques. Our method is developed through clustering, noise removal and classification approaches. Accordingly, we use expectation maximization, principal component analysis and support vector machine for clustering, noise removal and classification tasks, respectively. We also develop the proposed method for incremental situation by applying the incremental principal component analysis and incremental support vector machine for incremental learning of data. Experimental results on Pima Indian Diabetes dataset show that proposed method remarkably improves the accuracy of prediction and reduces computation time in relation to the non-incremental approaches. The hybrid intelligent system can assist medical practitioners in the healthcare practice as a decision support system.
Asunto(s)
Algoritmos , Diabetes Mellitus/clasificación , Aprendizaje Automático , Diabetes Mellitus/diagnóstico , Humanos , Modelos EstadísticosRESUMEN
A micro-mesoporous activated carbon (AC) was produced via an innovative approach combining microwave pyrolysis and chemical activation using NaOH/KOH mixture. The pyrolysis was examined over different chemical impregnation ratio, microwave power, microwave irradiation time and types of activating agents for the yield, chemical composition, and porous characteristic of the AC obtained. The AC was then tested for its feasibility as textile dye adsorbent. About 29â¯wt% yield of AC was obtained from the banana peel with low ash and moisture (<5â¯wt%), and showed a micro-mesoporous structure with high BET surface area (≤1038â¯m2/g) and pore volume (≤0.80â¯cm3/g), indicating that it can be utilized as adsorbent to remove dye. Up to 90% adsorption of malachite green dye was achieved by the AC. Our results indicate that the microwave-activation approach represents a promising attempt to produce good quality AC for dye adsorption.
Asunto(s)
Carbón Orgánico , Colorantes/química , Microondas , Adsorción , Carbono , Colorantes/aislamiento & purificación , Porosidad , Industria Textil , Textiles , Contaminantes Químicos del Agua/aislamiento & purificaciónRESUMEN
This study focuses on the evaluation of the performance of Chlorella sp. in removing nutrient in aquaculture wastewater and its correlation with the kinetic growth of Chlorella sp. The treatment was applied with various Chlorella sp. inoculation dosage ranging from 0% to 60% (v/v) of wastewater. The optimum inoculation dosage was recorded at 30% (v/v) with effluent concentration of ammonia and orthophosphate recording at 0.012mgL(-1) and 0.647mgL(-1), respectively on Day 11. The optimum dosage for bio-flocculation process was obtained at 30mgL(-1) of Aspergillus niger with a harvesting efficiency of 97%. This type of development of phytoremediation with continuous bio-harvesting could promote the use of sustainable green technology for effective wastewater treatment.
Asunto(s)
Aspergillus niger/metabolismo , Bagres/microbiología , Chlorella/metabolismo , Aguas Residuales/microbiología , Contaminantes Químicos del Agua/metabolismo , Purificación del Agua/métodos , Amoníaco/metabolismo , Animales , Biodegradación Ambiental , Reactores Biológicos/microbiología , Técnicas de Cocultivo , Fosfatos/metabolismoRESUMEN
A study was performed to determine the effect of Conway and f/2 media on the growth of microalgae genera. Genera of Chlorella sp., Dunaliella sp., Isochrysis sp., Chaetoceros sp., Pavlova sp. and Tetraselmis sp. were isolated from the South China Sea. During the cultivation period, the density of cells were determined using Syringe Liquid Sampler Particle Measuring System (SLS-PMS) that also generated the population distribution curve based on the size of the cells. The population of the microalgae genera is thought to consist of mother and daughter generations since these microalgae genera reproduce by releasing small non-motile reproductive cells (autospores). It was found that the reproduction of Tetraselmis sp., Dunaliella sp. and Pavlova sp. could be sustained longer in f/2 Medium. Higher cell density was achieved by genus Dunaliella, Chlorella and Isochrysis in Conway Medium. Different genera of microalgae had a preference for different types of cultivation media.
Asunto(s)
Chlorella/crecimiento & desarrollo , Microalgas/crecimiento & desarrollo , Agua de Mar/química , Aguas Residuales/química , Purificación del Agua/métodos , China , Microalgas/efectos de los fármacos , Nitratos/química , Nitratos/metabolismo , Océanos y Mares , Densidad de Población , Factores de TiempoRESUMEN
In this batch study, the adsorption of malathion by using granular activated carbon with different parameters due to the particle size, dosage of carbons, as well as the initial concentration of malathion was investigated. Batch tests were carried out to determine the potential and the effectiveness of granular activated carbon (GAC) in removal of pesticide in agricultural run off. The granular activated carbon; coconut shell and palm shells were used and analyzed as the adsorbent material. The Langmuir and Freundlich adsorption isotherms models were applied to describe the characteristics of adsorption behavior. Equilibrium data fitted well with the Langmuir model and Freundlich model with maximum adsorption capacity of 909.1mg/g. The results indicate that the GAC could be used to effectively adsorb pesticide (malathion) from agricultural runoff.