Photothermal self-floating aerogels based on chitosan functionalized with polydopamine and carbon nanotubes for removal of arsenic from wastewater.

Although wastewater disposal in evaporation ponds may be a cost-effective strategy for wastewater management, it overlooks water recycling and can possibly pose significant threats to the surrounding environment. The development of photothermal materials with functional groups capable of adsorbing toxic contaminants offers a promising opportunity for detoxification and potentially solar-driven recycling of wastewater disposed in evaporation ponds. In this study, ultralight aerogels based on chitosan (Ch), a natural biodegradable polymer, functionalized with mussel-inspired polydopamine (PDA) and carbon nanotubes (CNT) were fabricated through a facile approach and examined for the removal of arsenic from water.

Long-term leaching characteristic study of coal processing waste streams.

A study of the mobility of major and potentially hazardous trace elements from coal processing waste materials was conducted using two types of leaching tests. The baseline leaching test simulates stable waste storage under water, whereas the kinetic test models the storage of waste under more variable conditions including intermittent exposure to air and variations in humidity. Coarse and fine refuse materials were obtained from three commercial coal preparation plants that were being used to upgrade US bituminous run-of-mine coal containing low-to-high amounts of pyritic sulfur.

Development of an electrical conductivity screening test for mine waste assessments.

An environmental concern at mining operations is the potential leaching of trace elements from overburden and byproduct streams of processing plants. To provide a timely assessment of this concern, electrical conductivity of the leachate emanating from the plant waste streams can be measured as an indicator of the trace element content levels using the USGS Field Leach Test (FLT). However, the research reported in this publication revealed the need to modify the FLT procedure to improve the precision of the test results.