Due to alarming increase in population and rapid industrialization, drinking water quality is being deteriorated day by day in Pakistan. This review sums up the outcomes of various research studies conducted for drinking water quality status of different areas of Pakistan by taking into account the physicochemical properties of drinking water as well as the presence of various pathogenic microorganisms. About 20% of the whole population of Pakistan has access to safe drinking water. The remaining 80% of population is forced to use unsafe drinking water due to the scarcity of safe and healthy drinking water sources. The primary source of contamination is sewerage (fecal) which is extensively discharged into drinking water system supplies. Secondary source of pollution is the disposal of toxic chemicals from industrial effluents, pesticides, and fertilizers from agriculture sources into the water bodies. Anthropogenic activities cause waterborne diseases that constitute about 80% of all diseases and are responsible for 33% of deaths. This review highlights the drinking water quality, contamination sources, sanitation situation, and effects of unsafe drinking water on humans. There is immediate need to take protective measures and treatment technologies to overcome unhygienic condition of drinking water supplies in different areas of Pakistan.
1 August 2014 in Ecotoxicology and Environmental Safety
Arsenic (As) contamination of groundwater reservoirs is a global environmental and health issue given to its toxic and carcinogenic nature. Over 170 million people have been affected by As due to the ingestion of As-contaminated groundwater. Conventional methods such as reverse osmosis, ion exchange, and electrodialysis are commonly used for the remediation of As-contaminated water; however, the high cost and sludge production put limitations on their application to remove As from water. This review critically addresses the use of various agricultural waste materials (e.g., sugarcane bagasse, peels of various fruits, wheat straw) as biosorbents, thereby offering an eco-friendly and low-cost solution for the removal of As from contaminated water supplies. The effect of solution chemistry such as solution pH, cations, anions, organic ligands, and various other factors (e.g., temperature, contact time, sorbent dose) on As biosorption, and safe disposal methods for As-loaded biosorbents to reduce secondary As contamination are also discussed.