Investigation of mechanism and critical parameters for removal of arsenic from water using Zr-TiO2 composite

Environmental risk assessment of chronic arsenic in drinking water and prevalence of type-2 diabetes mellitus in Pakistan

Chronic arsenic (As) unprotection in drinking water can lead to Type 2 Diabetes Mellitus (T2DM). The purpose of this study was to investigate the association between chronic As in drinking water and the prevalence of T2DM. A study was conducted in targeted urban areas of Peshawar city of KPK, Pakistan, where drinking water is heavily contaminated with chronic arsenic. Participants protected to arsenic were selected from Kohat city of KPK, Pakistan (where people consumed water that is free from As contamination) and treated as the control group. People with arsenic-related skin lesions were defined as participants unprotected to arsenic. T2DM was diagnosed using a glucometer following the fasting blood glucose ≥6.0 mmol L^-1 from the WHO guideline. The common odds ratio for T2DM among participants unprotected to arsenic was <4. The Mantel-Haenszel weighted prevalence ratio with 95% of confidence interval for confounding factors were (age <4 m femininity <4 and body mass index >4). The results revealed that designated association were important. The findings suggested that unprotected chronic arsenic in drinking water may be a risk factor of T2DM.

Characterizations and mechanisms for synthesis of chitosan-coated Na-X zeolite from fly ash and As(V) adsorption study

Solid waste fly ash with low aluminum of Yunnan Province in China was used as pristine material to prepared chitosan-coated Na-X zeolite, and the obtained composite material was employed as As(V) adsorbent. Then, the prepared materials were characterized by XRD, FT-IR, and XPS. And the results suggested that the low aluminum fly ash was successfully convert into Na-X zeolite, and the mineralization between Si-OH of the obtained Na-X zeolite and C-OH of chitosan was the dominated mechanism for coated chitosan over the surface of Na-X zeolite. From the batch experiments of As(V) removal, it has been found that the coated chitosan could significantly improve As(V) performance of Na-X zeolite. The optimal working pH for removal As(V) by chitosan-coated Na-X zeolite was attained at pH 2.1 ± 0.1, and the maximum adsorption capacity was 63.23 mg/g. And the adsorption data at different interval time was excellent fitted by pseudo-second-order kinetic model. From the analyze of XPS, the results suggested that As(V) uptake over adsorbent by the bond of As-N and As-O and the surface hydroxyl group of Al-OH and -NH₂ were involved in uptake As(V) from acid wastewater.