Bacteriological quality of spring water in Bahrain

Summary The bacteriological quality of untreated spring waters in Bahrain were evaluated. Samples were collected from 12 natural springs and analysed for total plate count, total coliform, total faecal coliform, total faecal streptococci and occurrence ofShigella andSalmonella. The total bacterial counts ranged from 2.4×10¹ to 1.6×10⁴ CFU mL^–1 with an average of 2.8×10³.The coliform organisms were present in all springs. Faecal coliforms were present in 11 out of 12 springs studied, and three springs were heavily contaminated. Based on criteria which used the ratio of faecal coliform to faecal streptococci, all springs studied may be contaminated with human wastes, except one spring which may be contaminated with animal wastes. NeitherSalmonella norShigella were detected in any of the spring waters. It is concluded that the spring waters studied are unsuitable for human consumption unless disinfected.Dr Abdulrahman O. Musaiger is the senior author, to whom correspondence should be addressed. He is Head of the Nutrition Unit at the Bahrain Public Health Directorate. Mr Zakaria A. Khunji is a qualified microbiologist and the nutritionist at the Unit. Mr Hussain A. Mohana is a graduate and technician in charge of the food and water microbiology section at the Public Health Laboratory, Ministry of Health, Bahrain.     

Epidemiological study on Listeria monocytogenes in Egyptian dairy cattle farms’ insights into genetic diversity of multi-antibiotic-resistant strains by ERIC-PCR

Environmental Science and Pollution Research - Listeria monocytogenes (L. monocytogenes) is frequently detected in ruminants, especially dairy cattle, and associated with the sporadic and epidemic...     

Sequestration of toxic Pb（II） ions by chemically treated rubber （Hevea brasiliensis ） leaf powder

Rubber leaf powder (an agricultural waste) was treated with potassium permanganate followed by sodium carbonate and its performance in the removal of Pb(II) ions from aqueous solution was evaluated. The interactions between Pb(II) ions and functional groups on the adsorbent surface were confirmed by Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) coupled with X-ray energy dispersive spectroscopy (EDX). The effects of several important parameters which can affect adsorption capacity such as pH, adsorbent dosage, initial lead concentration and contact time were studied. The optimum pH range for lead adsorption was 4–5. Even at very low adsorbent dosage of 0.02 g, almost 100% of Pb(II) ions (23 mg/L) could be removed. The adsorption capacity was also dependent on lead concentration and contact time, and relatively a short period of time (60–90 min) was required to reach equilibrium. The equilibrium data were analyzed with Langmuir, Freundlich and Dubinin-Radushkevich isotherms. Based on Langmuir model, the maximum adsorption capacity of lead was 95.3 mg/g. Three kinetic models including pseudo first-order, pseudo second-order and Boyd were used to analyze the lead adsorption process, and the results showed that the pseudo second-order fitted well with correlation coefficients greater than 0.99.