Antibiofouling hollow-fiber membranes for dye rejection by embedding chitosan and silver-loaded chitosan nanoparticles

Environmental Chemistry Letters - The removal of toxic dyes from the wastewater and industrial effluents is a major environmental challenge. Various techniques have been employed for the removal of...     

Risk Assessment of Physico-Chemical Contaminants in Groundwater of Pettavaithalai Area, Tiruchirappalli, Tamilnadu – India

A study was carried out in Pettavaithalai area to evaluate the current status of physico-chemical contaminants and their sources in groundwater. Groundwater samples collected from pettavaithalai area in 15 different stations were analyzed every alternative months over a period of two years from August 2000 to June 2002. A sugar mill is situated at the heart of the study area. Three profiles (profile A, B and C) were selected based on the direction in which the sugar mill effluent flows. In each profile five samples were collected from five different station at a regular distance of about 1 Km. The physico-chemical parameters such as pH, EC TDS, TH, NO₃, SO₄, PO₄, Na, K, Ca, Mg, DO, BOD and COD have been analyzed. The results showed that among the three profiles, many of the estimated physico-chemical parameters of profile C were very high when compared to profile B and A which indicates the poor quality of the groundwater around this area.     

Factors Affecting Participating Farmers’ Willingness-to-pay for the Tree Farming Fund: A Study in a Participatory Forest in Bangladesh

This paper examined the factors that might influence participating farmers’ willingness-to-pay for the Tree Farming Fund (TFF) established for sustainable development of participatory forest management (PFM). Information on willingness-to-pay, socioeconomic characteristics, and attitudes of participating farmers toward TFF were obtained from interviews with 581 participating farmers. Logistic regression analysis was used to determine the dominant factors that might influence participating farmers’ willingness-to-pay for the TFF. The results showed that participating farmers’ willingness-to-pay was significantly affected by (i) family income; (ii) education level; (iii) confidence that his aspired benefits will be received; (iv) agreement with the statement that ‘PFM is sustainable under the present state of management’; (v) agreement with the statement that ‘PFM is a good strategy for forest conservation’; and (vi) knowledge of PFM strategies. Thus, participating farmers with a higher level of education, higher income and positive attitudes toward TFF tended to express more willingness-to-pay. Establishment of TFF could be an effective strategy in implementing sustainable PFM in Bangladesh. For this strategy to succeed, however, active partnership between the participating farmers and Forest Department is required. Participating farmers’ attitudes toward TFF should therefore be taken into consideration as should the results of this study, which are important indicators of participating farmers’ positive attitudes toward TFF.     

Assessing spatio-temporal trend of vector breeding and dengue fever incidence in association with meteorological conditions

Th aim of this study is to investigate spatio-temporal trends of dengue vector breeding and epidemic (disease incidence) influenced by climatic factors. The spatio-temporal (low-, medium-, and high-intensity periods) evaluation of entomological and epidemiological investigations along with climatic factors like rainfall (RF), temperature (T_max), relative humidity (RH), and larval indexing was conducted to develop correlations in the area of Lahore, Pakistan. The vector abundance and disease transmission trend was geo-tagged for spatial insight. The sufficient rainfall events and optimum temperature and relative humidity supported dengue vector breeding with high larval indices for water-related containers (27–37%). Among temporal analysis, the high-intensity period exponentially projected disease incidence followed by post-rainfall impacts. The high larval incidence that was observed in early high-intensity periods effected the dengue incidence. The disease incidence had a strong association with RF (r = 0.940, α = 0.01). The vector larva occurrence (r = 0.017, α = 0.05) influenced the disease incidence. Similarly, RH (r = 0.674, α = 0.05) and average T_max (r = 0.307, α = 0.05) also induced impact on the disease incidence. In this study, the vulnerability to dengue fever highly correlates with meteorological factors during high-intensity period. It provides area-specific understanding of vector behavior, key containers, and seasonal patterns of dengue vector breeding and disease transmission which is essential for preparing an effective prevention plan against the vector.     

Modeling and simulation of landfill gas production from pretreated MSW landfill simulator

The cumulative landfill gas (LFG) production and its rate were simulated for pretreated municipal solid waste (MSW) landfill using four models namely first order exponential model, modified Gompertz model, single component combined growth and decay model and Gaussian function. Considering the behavior of the pretreated MSW landfill, a new multi component model was based on biochemical processes that occurring in landfilled pretreated MSW. The model was developed on the basis of single component combined growth and decay model using an anaerobic landfill simulator reactor which treats the pretreated MSW. It includes three components of the degradation i.e. quickly degradable, moderately degradable and slowly degradable. Moreover, the developed model was statistically analyzed for its goodness of fit. The results show that the multi components LFG production model is more suitable in comparison to the simulated models and can efficiently be used as a modeling tool for pretreated MSW landfills. The proposed model is likely to give assistance in sizing of LFG collection system, generates speedy results at lower cost, improves cost-benefit analysis and decreases LFG project risk. It also indicates the stabilization of the landfill and helps the managers in the reuse of the landfill space. The proposed model is limited to aerobically pretreated MSW landfill and also requires the values of delay times in LFG productions from moderately and slowly degradable fractions of pretreated MSW.     

Assessment of the state of agroecosystem sustainability using landscape indicators: a comparative study of three rural areas in Greece

The research was based on a comparative study of three representative rural areas (Dovras, Larissa, and Messapia) in Greece. Remote sensing data were collected (maps, aerial photographs) for the landscape analysis and elaborated using GIS linked with economic and social parameters regarding land use. By using a selected core set of landscape indicators, this research aims at providing a useful tool for assessing agroecosystem management at territorial level and hopefully assist decision-making for the promotion of sustainability. The selected tool showed that the study area of Messapia presented the highest level of environmental sustainability, while the area of Dovras showed the best combination of agricultural productivity and landscape management. Results showed that the ecoregions of Dovras, Larissa, and Messapia presented a landscape composed of important ecological function areas in the percentages of 40%, 15%, and 70%, respectively, and of cultivated areas in the percentages of 55%, 71.19%, and 19.75%, respectively.     

Assessment of radiological hazard of NORM in Margalla Hills limestone, Pakistan

Studies on naturally occurring radioactive material (NORM) in the limestone from the Margalla Hills have been carried out by measuring gamma activity and to access its radiological implications if any. For data acquisition, a High-Purity Germanium detector was employed. The activity concentrations of (226)Ra, (232)Th, and (40)K were found to be 14.32?±?0.24, 2.05?±?0.04, and 13.80?±?0.20 Bq kg(-1), respectively. These values are relatively lower as compared to that in the limestone of other countries and much lower than the values reported for the natural building stones. The average specific activities due to (226)Ra were found to be higher when compared with (40)K and (232)Th. Indices of radium equivalent activity (Ra(eq)), internal hazard (H(in)), indoor absorbed gamma dose rate (D(R,)), and corresponding annual effective dose (E(eff)) were also determined for the limestone-made rooms. All of these indices were found to be in the lower ranges. The Margalla Hills limestone does not pose any excessive radiological health hazard as a building material and in industrial uses for a common man.     

Environmental and socio-economic impacts of pipe drainage in Pakistan

Many drainage schemes and salinity control projects have been executed world wide. Pipe drainage has widely been used in Pakistan, Egypt and India to control waterlogging. The impact of pipe drainage on land and water was evaluated in this paper using data of three pipe drainage projects in Pakistan namely Khushab Salinity Control and Reclamation Project, Fourth Drainage Project in Faisalabad and Swabi Salinity Control and Reclamation Project. Data by regular monitoring of these projects were collected. The effect of pipe drainage on water table depth at these three locations has been compared. Water quality and soil salinity improvement due to the pipe drainage has also been investigated. Data, related to water table depths and discharges from drain pipes/wells, was collected. Observation wells, installed at various places by the Water and Power Development Authority, were used for collection of this data. To evaluate the impact of the projects on salinity, soil samples from all the three locations were tested. A questionnaire was prepared to get the view of the people about the projects. It was revealed that in these areas, due to subsurface pipe drainage, the percentage of the abandoned land has been considerably decreased. Over drainage was observed in a few places of the projects. The farmers at such places were asked to change their cropping patterns. Ultimately, there has been an increase in area under cultivation, crop yields and cropping intensity in the projects’ area.