Removal of hydrophilic, hydrophobic, and charged xenobiotic organic compounds from greywater using green wall media.

Green walls offer a novel on-site approach for greywater treatment and reuse in densely build urban environments. However, they need to be engineered for effective removal of a wide range of emerging contaminants such as xenobiotic organic compounds (XOCs), which may be present in greywater due to extensive use of personal care products and household chemicals. This study used laboratory column design and batch experiments to investigate the performance of three lightweight green wall media (coco coir, zeolite, and perlite) and their mixture in three different combinations for the removal of twelve XOCs, covering wide range of hydrophilic, hydrophobic, and charged pollutants in greywater. The experiments were designed to assess the removal of targeted XOCs under different operational condition (i.e., hydraulic loading, infiltration rate, drying) and uncover the dominant mechanisms of their removal. Results showed excellent removal (>90%) of all XOCs in coco coir and media mix columns at the start of the experiment (i.e., fresh media and initial 2 pore volume (PV) of greywater dosing). The removal of highly hydrophobic and positively charged XOCs remained high (>90%) under all operational conditions, while hydrophilic and negatively charged XOCs exhibited significant reduction in removal after 25 PV and 50 PV, possibly due to their low adsorption affinity and electrostatic repulsion from negatively charged media. The effect of infiltration rate on the removal of XOCs was not significant; however, higher removal was achieved after 2-weeks of drying in coco coir and media mix columns. The dominant removal mechanism for most XOCs was found to be adsorption, however, a few hydrophilic XOCs (i.e., acetaminophen and atrazine) exhibited both adsorption and biodegradation removal processes. While findings showed promising prospects of unvegetated media for removing XOCs from greywater, long term studies on vegetated green wall systems are needed to understand any synergetic contribution of plants and media in removing these XOCs.

The comparative performance of lightweight green wall media for the removal of xenobiotic organic compounds from domestic greywater.

Green walls can provide an aesthetic approach to treat domestic greywater in urban landscapes. However, the widespread adoption of green walls for greywater treatment depends on its performance to remove the emerging contaminants from greywater such as xenobiotic organic compounds (XOCs). In this study, the performance of five lightweight green wall media types (zeolite, perlite, date seeds, coffee grinds, and coco coir) was evaluated for the removal of six XOCs representing a range of hydrophilic to hydrophobic organic micropollutants in domestic greywater (acetaminophen, diethyltoluamide, bisphenol A, oxybenzone, triclosan, nonylphenol). The adsorption affinity of targeted XOCs on different green wall media types, the role of contact time on XOCs removal, and the impact of background pollutants in greywater matrix on the adsorption of XOCs were analysed. Results indicate that removal of XOCs was higher using carbonaceous waste materials (date seeds, coffee grinds, and coco coir) as compared to natural minerals (zeolite and perlite). Moreover, the adsorption of XOCs increased with the increase in pollutant hydrophobicity. All XOCs showed highest removal using coco coir with fast adsorption kinetics, achieving 90% of the removal in 30 min. The only exception was acetaminophen that showed best removal using zeolite but exhibited slow adsorption kinetics with 90% of the removal attained in 24 h. The initial adsorption kinetics (<30 min) of XOCs in greywater were adversely affected by the presence of background pollutants, indicating the need of higher residence time of greywater in green wall system for better removal of XOCs. Based on the findings of this batch study, it is recommended to design a green wall system with more than 30 min of greywater residence time using a mixture of coco coir and zeolite for effective removal of XOCs from domestic greywater.

Encapsulated benzoic acid supplementation in broiler diets influences gut bacterial composition and activity.

1. The present study investigated the effects of encapsulated benzoic acid (BA) supplementation in broiler feed on performance and gastrointestinal microbiota. 2. Eighty broilers were randomly divided into two groups. Birds in the control group were fed on maize-soybean-based diets. Birds in the treatment group were provided the same diet supplemented with 2 g/kg BA encapsulated in a vegetable oil matrix. 3. At the end of the trial (d 35), pH, bacterial composition and metabolites were determined in the crop, jejunum, ileum and caecum. 4. Growth performance variables and pH were not significantly different. 5. BA concentration decreased rapidly in the proximal gut. However, the treatment diet showed higher BA in the crop, jejunum, ileum and caecum. 6. Total lactate in the crop and D-lactate in the jejunum was higher in the BA treated group. Caecal total and branched chain fatty acids were decreased due to the treatment. 7. Lactobacilli populations were significantly altered by BA supplementation. A trend for increased lactobacilli was observed in the crop, while it became significant in the jejunum and ileum. Lactobacillus species responded differently to the treatment. Four of 5 measured Lactobacillus species, particularly in the ileum, followed the course observed for total lactobacilli; only Lactobacillus salivarius was not modified. 8. Correlation analysis showed that BA modified the intestinal microbiota. Lactobacilli correlated negatively to all studied clostridial clusters and enterobacteria. Clostridial clusters IV and XIVa were significantly increased in the jejunum, whereas only clostridial cluster XIVa was increased in the caecum. 9. Encapsulated BA modified the intestinal microbiota which can lead to the conclusion, that the main beneficial mode of action of BA in the gut appears to be the enhancement of lactic acid bacteria, which in turn may act as a vanguard against pathogens.

Programmable fast-freezing method improves the post-thaw motion dynamics, integrities of plasmalemma, mitochondrial transmembrane, DNA and, acrosome, and in vivo fertility of water buffalo (Bubalus bubalis) spermatozoa.

The effects of freezing methods (FR1, nonprogrammable/static, 5 cm above liquid nitrogen [LN2 ] for 10 min, plunging in LN2 ; FR2, programmable medium, +4°C to -15°C at 3°C min-1 , from -15 to -80°C at 10°C min-1 and final holding for 1 min at -80°C, plunging in LN2 ; FR3, programmable fast, from initial holding at +4°C for 2 min, from +4°C to -20°C at 10°C min-1 , from -20°C to -100°C at 30°C min-1 , final holding for 1 min at -100°C and plunging in LN2 ) were assessed on post-thaw in vitro quality and in vivo fertility of water buffalo spermatozoa. Mean sperm progressive motility (%), rapid velocity (%), average path velocity (µm s-1 ), straight line velocity (µm s-1 ), curved line velocity (µm s-1 ), integrities (%) of plasmalemma, mitochondrial transmembrane, DNA and acrosome were higher (p < .05) in samples cryopreserved with FR3 compared to FR1 and FR2. Similarly, in vivo fertility (%) of buffalo spermatozoa was higher (p < .05) with FR3 than FR1 (%; 68.0 versus 50.0). We concluded that programmable fast-freezing method (FR3) improves the post-thaw in vitro quality and in vivo fertility of water buffalo spermatozoa.

HIV and other sexually transmitted infections among men, transgenders and women selling sex in two cities in Pakistan: a cross-sectional prevalence survey.

OBJECTIVES: The extent and possibilities of spread of the HIV epidemic are not fully understood in Pakistan. A survey was conducted among men, women and transgender populations selling sex in Rawalpindi (Punjab) and Abbottabad (North West Frontier Province) in order to inform evidence-based programme planning. METHODS: A cross-sectional survey was performed with participants recruited through respondent-driven sampling. Male and transgender sex workers were analysed in three gender groups; women were analysed as one group. Behavioural surveys were conducted and clinical specimens collected. Laboratory tests looked for evidence of acute infection (gonorrhoea, Chlamydia, syphilis, Trichomonas) and infection over the lifetime (HIV, herpes simplex virus-2, syphilis). Predictors of infection were explored using univariable and multivariable logistic regression. RESULTS: The prevalence of HIV was low in 917 male and transgender sex workers and absent in 533 female sex workers in the study. High levels of current sexually transmitted infections were found, predominantly among transgender sex workers. Risk behaviours were common and knowledge of HIV was extremely low. Multivariable analysis found a large number of factors associated with higher levels of infection, including experience of forced first sex. Protection against risk was low, but those sex workers who reported using condoms at last sex had lower rates of infection. CONCLUSIONS: The HIV epidemic is currently in its early stages among people who sell sex, but there may be potential for a much greater spread given the levels of other sexually transmitted infections found and the concomitant low levels of both protective knowledge and risk-reducing behaviours. Action is needed now to avert an epidemic. Framing interventions by upholding the recognition and protection of human rights is vital.

Epidemic of cutaneous leishmaniasis: 109 cases in a population of 500.

In February 2004, 4 patients aged 10-15 years presented at the Pakistan Institute of Medical Sciences with non-healing multiple ulcers on exposed parts. On the basis of history, clinical assessment and fine needle aspiration cytology, they were diagnosed as having cutaneous leishmaniasis. We were informed that several similar cases were present in their village. A team of doctors and technicians visited the area. A survey was conducted and another 105 cases with various morphological presentations were identified. The area was visited several times to find the vector, reservoirs and source of infection and to advise on controlling the epidemic.

Epidemic of cutaneous leishmaniasis: 109 cases in a population of 500

In February 2004, 4 patients aged 10-15 years presented at the Pakistan Institute of Medical Sciences with non-healing multiple ulcers on exposed parts. On the basis of history, clinical assessment and fine needle aspiration cytology, they were diagnosed as having cutaneous leishmaniasis. We were informed that several similar cases were present in their village. A team of doctors and technicians visited the area. A survey was conducted and another 105 cases with various morphological presentations were identified. The area was visited several times to find the vector, reservoirs and source of infection and to advise on controlling the epidemic