Biochar potential for long-term pharmaceutical remediation in flow-through tertiary wastewater systems

Area of Science:

• Environmental Science
• Water Treatment
• Materials Science

Background:

• Wastewater treatment plants (WWTPs) are not designed for pharmaceutical removal, leading to environmental contamination.
• Pharmaceuticals in the environment pose risks to ecosystems and human health.

Purpose of the Study:

• To investigate the adsorption capacity of five biochar materials for pharmaceutical removal from tertiary wastewater effluent.
• To evaluate biochar performance under dynamic flow conditions and varying pharmaceutical loads.

Main Methods:

• Packed bed column tests were conducted using tertiary wastewater effluent.
• Two conditions were tested: high pharmaceutical loads (16 spiked compounds) and normal working conditions (42 non-spiked compounds).
• Pharmaceutical concentrations were monitored over 45 weeks (635 bed volumes).

Main Results:

• Sewage sludge and forest biomass biochar demonstrated high adsorption efficiency (>99%).
• Adsorption capacity was influenced by biochar packing density, feedstock, and physicochemical properties.
• Fitted breakthrough curves revealed strong correlations between pharmaceutical charge, molecular size, and adsorption capacity.

Conclusions:

• Biochar, particularly from sewage sludge and forest biomass, shows significant potential for removing pharmaceuticals from wastewater effluent.
• Understanding biochar properties and pharmaceutical characteristics is key to optimizing removal processes.
• This research offers valuable insights for developing effective biochar-based wastewater treatment strategies.