Effect of acetate on lead toxicity to microbial biomass in a red soil

１ＩｎｔｒｏｄｕｃｔｉｏｎＥｎｖｉｒｏｎｍｅｎｔａｌｐｏｌｕｔｉｏｎｂｙｌｅａｄ，ｒｅｓｕｌｔｉｎｇｆｒｏｍｍｉｎｉｎｇａｎｄｓｍｅｌｔｉｎｇａｃｔｉｖｉｔｉｅｓ，ｓｅｗａｇｅｓｌｕｄｇｅｕｓａｇｅｉｎａｇｒｉｃｕｌｔｕｒｅａｎｄｃｏｎｔａｍｉｎａｔ...     

Implementation of food frequency questionnaire for the assessment of total dietary arsenic intake in Bangladesh: Part B, preliminary findings

Dietary intake of water and food has been identified as one of the major pathways for arsenic (As) exposure in the rural population of Bangladesh. Therefore, realistic assessment and measurement of dietary intake patterns are important for the development of an accurate estimate of As exposure and human health risk assessment. One important consideration is to identify an appropriate tool for measuring dietary intake. In this study an interviewer-administered Food Frequency Questionnaire (FFQ) was implemented to determine age and gender specific dietary intake. The developed FFQ was unique because it developed a synergy between field dietary assessment and As concentration measurements in various environmental media. The resulting integrated database provided an accurate framework for the process of As exposure and human health risk assessment. The preliminary results reported here from the FFQ demonstrated that this technique could be used in rural areas as a tool to assess As exposure and the associated human health risk.     

Jettability of reactive nylon materials for additive manufacturing applications

An inkjet printing process has been suggested for producing nylon 6 in an additive manufacturing approach and this paper reports on the jettability of molten reactive materials made by caprolactam with activator and catalyst to study the feasibility of the approach in an inkjet system. The materials physical properties which are important for jetting were characterized and then the melt supply behaviour in the system was studied and finally jetting trials were monitored to investigate the effect of parameter settings on the stability of the jet array. It was found that the surface tension and viscosity of all materials were within the suitable range. However, with the catalyst mixtures, microcrystals of the undissolved salt of the catalyst complex were found to influence the melt supply behaviour considerably. The mixtures had a narrower range of parameters where stability occurred compared with caprolactam. Monitoring the jet stability recommended a suitable range of jetting parameters for the deposition stage of researching the new approach. A higher level of instability was observed with the catalyst mixture especially when jetting with multiple nozzles due to the microcrystals.     

Study on the Physico-mechanical Properties of Photo-cured Chitosan Films with Oligomer and Acrylate Monomer

Chitosan films were prepared from dried prawn shell via chitin and then tensile properties like tensile strength (TS) and elongation at break (Eb) of the films were evaluated. Six formulations were developed using methyl methacylate (MMA) monomer and aliphatic urethane diacrylate oligomer (M-1200) in methanol along with photoinitator (Darocur-1664). Then the films were soaked in the formulations and irradiated under UV radiation at different doses for the improvement of physico-mechanical properties of chitosan films. The cured films were characterized by measuring TS, Eb, polymer loading (PL), water absorption and gel content properties. The formulation containing 43% MMA and 15% oligomer in methanol solution showed the best performance at 20th UV pass for 4 min soaking time.     

Laboratory-based assessment on similarities between dynamic behavior of MSW and clay

Journal of Material Cycles and Waste Management - The dynamic response of landfills under seismic loads is greatly dependent on stress–strain cyclic characteristics of municipal solid waste...     

Mimic Enzyme Based Cellulose Nanocrystals/PVA Nanocomposite Membranes for Enrichment of Biogas as a Natural Gas Substitute

Journal of Polymers and the Environment - Nanocomposite membranes promoted by mimic enzyme was developed and optimized for biogas upgrading at moderately high pressure applications up to...     

Determination of chlorothalonil residues in coffee

Coffee beans were treated with the fungicide chlorothalonil (2,4,5,6‐tetrachloro‐1,3‐benzene‐dicarbonitrile) and the residues were determined by high‐performance liquid Chromatograph (HPLC). Several techniques including Soxhlet extraction (SE), microwave‐assisted extraction (MAE) and accelerated solvent extraction (ASE) were compared for the extraction of residues. A column clean‐up procedure was developed to remove the co‐extractives in the extract before HPLC analysis. The overall mean recoveries from extracts obtained by SE, MAE and ASE were 89.2 ±3.9, 88.4 ±1.9 and 82.8 ±0.3, respectively. The results show that MAE followed by HPLC is a viable alternative to the commonly used SE and gas Chromatographic analysis for the determination of chlorothalonil in coffee.     

Bacteriological quality assessment of drinking water available at the flood affected areas of Peshawar

Monsoon flooding occurred in the main areas of the Khyber Pakhtunkhwa, Punjab, and Balochistan as well as parts of Gilgit Baltistan of Pakistan and Azad Jammu Kashmir in July 2010. Water-borne diseases such as cholera, enteric fever, and dysentery were common among the inhabitants of flood-affected areas which were selected for sample collection. In the present study, 10 sites in District Peshawar were selected and drinking water samples collected. These samples were analyzed for the total plate count (TPC), total coliform bacteria (TCB), total fecal coliform bacteria (TFCB), Escherichia coli (EC), Pseudomonas aeruginosa (PA), Vibrio cholerae (VB), Salmonella Shigella, and Staphylococcus aureus. The TPC ranged from 8 × 10¹ to 7 × 10⁴ CFU/ml. The TCB ranged from <1.1 to 280 MPN/100 ml. Twenty percent of the samples were contaminated with TFCB, EC, Salmonella, Shigella, and Staphylococcus aureus, while only one sample contaminated with PA. Forty percent of the samples were contaminated with VB. The surface and well water was greatly contaminated by flooding and major improvements on priority basis are essential.