Exploring the potential of bacterial-augmented floating treatment wetlands for the remediation of detergent-contaminated water.

Due to industrialization and urbanization, the use of detergents inadvertently led to contamination of aquatic environments, thus posing potential threat to aquatic organisms and human health. One of the main components of detergents is linear alkylbenzene sulfonate (LAS), which can cause toxic effects on living organisms, particularly aquatic life in the environment. In this study, floating treatment wetlands (FTWs) mesocosms were developed and augmented with LAS-degrading bacteria. The plant species, Brachiaria mutica (Para grass), was vegetated to establish FTWs and bacterial consortium (1:1:1:1) of Pseudomonas aeruginosa strain PJRS20, Bacillus sp. BRRH60, Acinetobacter sp. strain CYRH21, and Burkholderia phytofirmans Ps.JN was augmented (free or immobilized) in these mesocosms. Results revealed that the FTWs removed LAS from the contaminated water and their augmentation with bacteria slightly increased LAS removal during course of the experiment. Maximum reduction in LAS concentration (94%), chemical oxygen demand (91%), biochemical oxygen demand (93%), and total organic carbon (91%) was observed in the contaminated water having FTWs augmented with bacterial consortium immobilized on polystyrene sheet. This study highlights that the FTWs supported with immobilized bacteria on polystyrene sheets can provide an eco-friendly and sustainable solution for the remediation of LAS-bearing water, especially for developing countries like Pakistan.

This pilot-scale study provided insights to resolve the detergent-contaminated wastewater issue, using floating treatment wetlands (FTWs) augmented with bacteria. The FTWs augmented with bacteria immobilized on a polystyrene sheet and vegetated with Brachiaria mutica led to high degradation of LAS, a toxic compound of detergent, from the contaminated water.

The role of various ameliorants on geochemical arsenic distribution and CO2-carbon efflux under paddy soil conditions.

Climate change is a global challenge that is accelerated by contamination with hazardous substances like arsenic (As), posing threat to the agriculture, ecosystem and human health. Here, we explored the impact of various ameliorants on geochemical distribution of As in two soils with contrasting textures (sandy clay loam (Khudpur Village) and clay loam (Mattital Village)) under paddy soil conditions and their influence on the CO2-carbon efflux. The exchangeable As pool in clay loam soil increased as: lignite (0.4%) < biogas slurry (6%) < cow dung (9%), and < biochar (20%). However, in the sandy clay loam soil exchangeable soil As pool was found to be maximum with farmyard manure followed by biogas slurry, biochar and cow dung (17%, 14%, 13% and 7%, respectively). Interestingly, in the sandy clay loam soil the percentage As distribution in organic fraction was: biochar (38%) > cow dung (33%) > biogas slurry (23%) > sugarcane bagasse (22%) > farmyard manure (21%) that was higher compared to the clay loam soil (< 6% for all the amendments). In addition to the highest As immobilization by biochar in sandy clay loam soil, it also led to the lowest CO2-carbon efflux (1470 CO2-C mg kg-1) among all the organic/inorganic amendments. Overall, the current study advances our understanding on the pivotal role of organic amendments, notably biochar, in immobilizing As under paddy soil conditions with low (CO2) carbon loss, albeit it is dependent on soil and ameliorant types.

Enhanced capacity of thiol-functionalized sugarcane bagasse and rice husk biochars for arsenite sorption in aqueous solutions.

The utilization of biowastes for producing biochar to remove potentially toxic elements from water represents an important pathway for aquatic ecosystem decontamination. Here we explored the significance of thiol-functionalization on sugarcane bagasse biochar (Th/SCB-BC) and rice husk biochar (Th/RH-BC) to enhance arsenite (As(III)) removal capacity from water and compared their efficiency with both pristine biochars (SCB-BC and RH-BC). The maximum As(III) sorption was found on Th/SCB-BC and Th/RH-BC (2.88 and 2.51 mg g-1, respectively) compared to the SCB-BC and RH-BC (1.51 and 1.40 mg g-1). Relatively, a greater percentage of As(III) removal was obtained with Th/SCB-BC and Th/RH-BC (92% and 83%, respectively) at a pH 7 compared to pristine SCB-BC and RH-BC (65% and 55%) at 6 mg L-1 initial As(III) concentration, 2 h contact time and 1 g L-1 sorbent dose. Langmuir (R2 = 0.99) isotherm and pseudo-second-order kinetic (R2 = 0.99) models provided the best fits to As(III) sorption data. Desorption experiments indicated that the regeneration ability of biochars decreased and it was in the order of Th/SCB-BC (88%) > Th/RH-BC (82%) > SCB-BC (77%) > RH-BC (69%) up to three sorption-desorption cycles. Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy results demonstrated that the thiol (-S-H) functional groups were successfully grafted on the surface of two biochars and as such contributed to enhance As(III) removal from water. Spectroscopic data indicated that the surface functional moieties, such as -S-H, - OH, - COOH, and C = O were involved to increase As(III) sorption on thiol-functionalized biochars. This study highlights that thiol-grafting on both biochars, notably on SCB-BC, enhanced their ability to remove As(III) from water, which can be used as an effective technique for the treatment of As from drinking water.

Seroepidemiology and associated risk factors of hepatitis B and C virus infections among pregnant women attending maternity wards at two hospitals in Swabi, Khyber Pakhtunkhwa, Pakistan.

BACKGROUND & AIM: Hepatitis B and C infections are global issues that are associated with a massive financial burden in developing countries where vertical transmission is the major mode and remains high. This cross-sectional study was designed to investigate the seroepidemiology and associated risk factors of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections among 375 pregnant women attending antenatal care health facilities at Bacha Khan Medical Complex (BKMC) Shahmansoor and District Head Quarter (DHQ) Hospital Swabi, Khyber Pakhtunkhwa, Pakistan. METHODOLOGY: From a total of 375 pregnant women selected using systematic random sampling from both hospitals, 10 ml of blood samples were collected and alienated serum was examined for indicators identification through the Immuno-Chromatographic Test (ICT) and 3rd Generation Enzyme-Linked Immunosorbent Assay (ELISA). A pre-structured questionnaire was used to collect the socio-demographic data and possible risk factors. The data was analyzed via SPSS 23.0 statistical software. A chi-square analysis was performed to determine the association between variables. P-value < 0.05 was set statistically significant. RESULTS: The overall frequency of HBV and HCV among 375 pregnant women involved in the study was 3.7% and 2.1% respectively. None of the pregnant women were co-infected with HBV and HCV. Dental extraction (P = 0.001) and blood transfusion (P = 0.0005) were significantly allied with HBV infection while surgical procedure (P = 0.0001) was significantly associated with HCV infection. Moreover the sociodemographic characteristics: residential status (P = 0.017) and educational level (P = 0.048) were found significant risk factors of HBsAg and maternal age (P = 0.033) of anti-HCV, respectively. CONCLUSION & RECOMMENDATION: HBV and HCV infections are intermediary endemic in the study area. A higher prevalence of HBV was detected among pregnant mothers with a history of dental extraction, history of blood transfusion, resident to the urban area and low educational level. The age and surgical procedures were the potential risk factors found significantly associated with HCV positivity among pregnant mothers in our setup. Future negotiations to control vertical transmission should include routine antenatal screening for these infections early in pregnancy and the requirement of efficient preventive tools including the birth dose of the hepatitis B vaccine in combination with hepatitis B immune globulins to the neonate.