Retention Time

Groundwater contains iron (Fe) that can be difficult to remove by singular physical–chemical methods. The aim of this presented study was to investigate the suitability of up-flow aerated filters as an upgrading step for the removal of total Fe from groundwater. Granular activated carbon (GAC) was applied as a pollutant carrier and compared with Bio-Pac media (BPM) by conducting a column test to treat synthetic groundwater (SGW). Initially two adsorption kinetic studies were done for GAC. The effect of influent Fe concentration, hydraulic retention time (HRT) and air supply to the system were investigated using a column experiment. The sorption result follows pseudo-second-order kinetics with an adsorption amount of 1.36 mg/g. The column experiment results show that around 99% and 70% Fe removal efficiency can be achieved for the best condition of 3 mg/L influent Fe concentration with seven hours HRT for GAC and BPM respectively. The air supply into the column did not show any impro...

In many parts of the world, health problems have often been caused by untreated wastewater. The objective of this study was to determine thephysicochemical and parasitological determination of wastewater in Quetta city, Balochistan.In the present study, samples of water were collected from different areas of Quetta city including domestic wastewater, city nala, irrigated water, Police line hospital(hospital 1) wastewater and Mission hospital (hospital 2) wastewater were examined. The physicochemical parameters such as,pH, conductivity, TDS (Total dissolve solid) and some metals i.e., sodium and potassium values and the helminthes ova were calculated for each wastewater sample selected for the present study.The obtained results revealed that the parameters like pH, conductivity, TDS of all wastewater samples observed in the present study showed the values higher than the standard values suggested by WHO.While the values of sodium and potassium range from 20 to 30 mg/litrewere not mor...

Cacao is a promising high-value crop in the Philippines and is considered one of the key players globally in providing the raw materials for chocolate making. However, before the Philippines can take this market opportunity, production constraints from various pests should be addressed. The cacao pod borer (CPB), Conopomorpha cramerella, is one of the major insect pests of cacao in the Philippines, which can cause up to 50% annual loss or even higher if proper management is not employed. Management of CPB heavily relies on chemical control but is becoming unpopular because of its high cost and health risk to people and the environment. A number of efforts have been made to develop sex pheromones to monitor and control CPB. A field bioassay of the new blend of CPB sex pheromones was conducted in southern Philippines to determine its efficiency and identify the appropriate trap height placement in a cacao field, which is important in maximizing the efficiency of the sex pheromone trap...

In the Republic of Benin, the scelionid egg parasitoid Telenomus isis (Polaszek) is one of the most important control factors of the noctuid maize stem borer Sesamia calamistis. In the present study, the role of various sources of contact kairomones (male or virgin or mated female moths) and of the moth's oviposition substrate (leaf sheath versus filter paper; host plant

O objetivo neste trabalho foi estudar o efeito do tratamento alcalino da cana-de-açúcar com hidróxido de sódio (1,5 a 50% de NaOH) sobre a digestibilidade total e o consumo de matéria seca das dietas experimentais e as taxas de passagem das canas-de-açúcar. Foram utilizados quatro bovinos mestiços (Zebu x Holandês) alimentados com canas-de-açúcar in natura, hidrolisada, hidrolisada fenada e hidrolisada ensilada como fontes volumosas, constituindo 70% das dietas. O tratamento alcalino foi mais eficiente na fração fibra, proporcionando aumentos de pelo menos 45% na digestibilidade. Os aumentos de 25,0 e 16,7% no consumo das dietas contendo as cana-de-açúcar hidrolisada (1,5% PV) e hidrolisada fenada (1,4% PV) provavelmente foram influenciados pela maior digestibilidade da fibra. Os valores estimados de taxa de passagem ruminal no ceco-cólon e o tempo de retenção em cada compartimento não diferiram entre as cana-de-açúcar in natura, hidrolisada e hidrolisada fenada. Entretanto, para a ...