Potential of pineapple waste extract (PWE) as co-substrate in anaerobic digestion of rice straw washwater (RSWW): enhancement of biogas production

This study aims to investigate the potential methane yield by mono-anaerobic digestion of rice straw washwater (RSWW) and pineapple waste extract (PWE) as well as the co-digestion of both RSWW and PWE at a ratio of 50:50 (v/v). The experiment was conducted at a controlled mesophilic temperature of 37 °C in Upflow Anaerobic Sludge Blanket (UASB) reactor for a period of approximately 55 days. The process performances were evaluated based on the efficiency of COD removal and methane production in relation to other parameters such as pH, organic loading rate (OLR) and alkalinity ratio. This study confirmed that the rate of COD removal for RSWW, PWE, and RSWW:PWE (50:50) were achieved the stable condition at 81, 89, and 86% respectively. The alkalinity ratio value and pH throughout the experimental period remained below 0.30 and kept in the range of 6.5–7.0 indicated the stable and good environment existed for anaerobic digestion within the UASB reactor. This study implies that the co-digestion of RSWW:PWE found to improve the efficiency of COD removal and production of methane during the mono-digestion of RSWW from 81 to 86% and 0.093 to 0.13 LCH4/g CODrem by the increment of 6.2 and 40%, respectively

Report on the occurrence of the xanthid crab, <em>Demania armadillus</em> (Herbst, 1790) in Kalpakkam coastal waters, southeast India

1699-1701This report is a record of the occurrence of the xanthid crab Demania armadillus (Herbst, 1790) in Kalpakkam coastal waters, southeast India and the morphological features of two female specimens

First Record of Indian Hand Fish Halieutaea indica Annandale & Jenkins, 1910 From Chennai Coast, Tamil Nadu, India

882-884The present paper reports the first record of Indian hand fish Halieutaea indica from Kasimedu fishing harbour, Chennai coast. A systematic account of this species, description and distribution are provided. Its similarity with the species of Halieutaea stellata is also reported

Kinetic Approach for the Adsorption of Organophosphorous Pesticides from Aqueous Solution Using “Waste” Jute Fiber Carbon

Chemically activated “Waste” Jute Fiber carbon has been effectively used for the removal of five organophosphorous pesticides (malathion, monocrotophos, methylparathion, phosphamidon and dimethoate) from aqueous solutions. The prepared activated jute fiber carbon was characterized by using Elemental analyzer and proximate analysis methods. The adsorption equilibrium was examined at 28 ºC. Three different kinetic models, the pseudo first order, pseudo second order and Elovich kinetic models were selected to analyses the adsorption process. To compare the fitness of pseudo first order and pseudo second order, sum of the squares of the errors and correlation coefficient, r2 values were calculated. The Elovich model was used to confirm the chemisorptions

Obtenção e caracterização de carvão ativado de caroço de buriti (Mauritia flexuosa L. f.) para a avaliação do processo de adsorção de cobre (II) Production and characterization of the activated carbon from buriti stone (Mauritia flexuosa L. f.) to evaluate the adsorption's process of copper (II)

Na região amazônica, algumas indústrias despejam cobre nos corpos receptores que, em elevadas concentrações, é tóxico para os seres vivos. A remoção de cobre de efluentes industriais é realizada por diversos processos como a adsorção. Neste trabalho mostrou-se o resultado da adsorção de cobre (II) em carvão ativado de caroço de buriti carbonizado a 400 °C e ativado a 900 °C. O carvão ativado foi caracterizado em termos de área específica, tamanho dos poros, densidades aparente e real, porosidade, microscopia eletrônica de varredura, conteúdo de cinzas, pH, umidade, carbono fixo e grupos funcionais de superfície. O estudo de equilíbrio de adsorção avaliou a influência do diâmetro das partículas do carvão, do tempo de contato adsorvente/adsorbato, do pH e da concentração inicial da solução de cobre (II) sobre a remoção de cobre (II). Com base nos resultados, concluiu-se que há uma maior eficiência de remoção de cobre (II) para diâmetro < 0,595 mm, tempo de contato de 300 minutos, pH 4,0 e concentrações iniciais de cobre (II) de 50 e 80 mg L-1. O modelo matemático de Langmuir foi o que melhor se ajustou aos dados de equilíbrio de adsorção. A partir do tempo de contato de 15 minutos todas as concentrações de equilíbrio ficaram abaixo do máximo permitido de 1,0 mg L-1 previsto pela legislaç��o vigente para lançamento de efluentes em corpos receptores.<br>In the Amazon region some industries discharges copper into watercourse that in high concentrations is toxic to the biota. The removal of copper from industrial effluent is performed by several processes such as adsorption. This work shows the result of copper (II) adsorption on activated carbon obtained from buriti kernel, carbonized at 400 °C and activated at 900 °C. The activated carbon was characterized according to specific area, pore size, apparent and real density, porosity, scanning electron microscopy, ash content, pH, moisture, fixed carbon and surface functional groups. The study of adsorption equilibrium evaluated the influence of the coal particles diameter, contact time adsorbent/adsorbate, pH and copper (II) solution initial concentration on copper (II) remotion. The results showed a higher removal efficiency of copper (II) to the diameter D < 0.595 mm, contact time of 300 minutes, pH of 4.01 and the copper (II) initial concentrations of 50 and 80 mg L-1. The mathematical model of Langmuir was the best fit to the adsorption equilibrium data. From the contact time of 15 minutes, all the equilibrium concentrations were below the allowed maximum of 1,0 mg L-1 provided by law for discharging effluents into receiving bodies