An analytical study on municipal wastewater to energy generation, current trends, and future prospects in South Asian developing countries (an update on Pakistan scenario)

Fates of Benzotriazoles, Benzothiazoles, and p-Phenylenediamines in Wastewater Treatment Plants in Malaysia and Sri Lanka

“…These were comparable to the removal efficiencies of BTR and BTH congeners in Indian WWTPs (67%–82% and 40%–52%, respectively) and China (24%–72%) , but lower than those in developed countries including Greece (18%–100% and 77%–91%, respectively), , Germany (−3%–68% and 22%–100%, respectively), ,− , Switzerland (−47%–74% for BTRs), Spain (−400%–100% and 1.5%–100%, respectively), ,,− and Australia (39%–93% for BTRs) . Wastewater treatment systems currently used in South and Southeast Asia are inadequate and are mainly limited to primary processes because of concerns about costs . More effort should be made to improve WWTP infrastructure and technology to produce clean water and tackle economic, social, and environmental challenges.…”

“…South Asia is one of the most heavily populated parts of the world, and the population is expected to increase by ∼500 × 10 6 from 2018 to 2050 . Only primary or simple secondary treatments are used in WWTPs in South and Southeast Asia, and ∼90% of municipal wastewater is not adequately treated . Rubber is mostly produced in Asia, with 93% of global natural rubber production (13.8 × 10 6 t) occurring in Asia in 2019 () .…”

“…The main sources of BTRs, BTHs, and PPDs to the aquatic environment are surface runoff and direct discharges of raw or treated wastewater from industrial and municipal wastewater treatment plants (WWTPs) . Around the world, ∼ 331 km 3 of urban wastewater is produced each year, but only a small proportion is treated and safely reused . Existing treatment facilities cannot completely remove BTRs, BTHs, and PPDs, meaning these chemicals are released into water bodies receiving WWTP effluent. , WWTPs are therefore major sources of BTRs, BTHs, and PPDs to aquatic environments.…”

“…BTRs, BTHs, and PPDs have been detected in WWTPs in Germany, − Switzerland, and Spain, , and the highest concentrations in influents and effluents were tens of micrograms per liter. Smaller proportions of wastewater are collected and treated in developing countries than developed countries . There is an urgent need to improve our understanding of the fates of these chemicals in WWTPs in developing countries and the risks posed.…”

“…28 Around the world, ∼ 331 km 3 of urban wastewater is produced each year, but only a small proportion is treated and safely reused. 29 Existing treatment facilities cannot completely remove BTRs, BTHs, and PPDs, meaning these chemicals are released into water bodies receiving WWTP effluent. 3,9 WWTPs are therefore major sources of BTRs, BTHs, and PPDs to aquatic environments.…”