Experimental and modeling investigations on the unexpected hydrogen sulfide rebound in a sewer receiving nitrate addition: Mechanism and solution.

Biogenic hydrogen sulfide is an odorous, toxic and corrosive gas released from sewage in sewers. To control sulfide generation and emission, nitrate is extensively applied in sewer systems for decades. However, the unexpected sulfide rebound after nitrate addition is being questioned in recent studies.

A pilot-scale sulfur-based sulfidogenic system for the treatment of Cu-laden electroplating wastewater using real domestic sewage as electron donor.

Elemental sulfur (S) reduction process has been demonstrated as an attractive and cost-efficient approach for metal-laden wastewater treatment in lab-scale studies. However, the system performance and stability have not been evaluated in pilot- or large-scale wastewater treatment. Especially, the sulfide production rate and microbial community structure may significantly vary from lab-scale system to pilot- or large-scale systems using real domestic sewage as carbon source, which brings questions to this novel technology.

Integration of •SO-based AOP mediated by reusable iron particles and a sulfidogenic process to degrade and detoxify Orange II.

The sulfate radical (•SO)-based advanced oxidation processes (AOPs) for the degradation of refractory organic pollutants consume a large amount of persulfate activators and often generate toxic organic by-products. In this study, we proposed a novel iron-cycling process integrating •SO-based AOP mediated by reusable iron particles and a sulfidogenic process to degrade and detoxify Orange II completely. The rusted waste iron particles (Fe@FeO), which contained Fe/Fe oxides (FeO) on the shell and zero-valent iron (Fe) in the core, efficiently activated persulfate to produce •SO and hydroxyl radicals (•OH) to degrade over 95% of Orange II within 120 min.

Overlooked pathways of denitrification in a sulfur-based denitrification system with organic supplementation.

Elemental sulfur-driven autotrophic denitrification (SADN) is a cost-effective approach for treating secondary effluent from wastewater treatment plants (WWTPs). Additional organics are generally supplemented to promote total nitrogen (TN) removal, reduce nitrite accumulation and sulfate production, and balance the pH decrease induced by SADN. However, understanding of the impacts of organic supplementation on microbial communities, nitrogen metabolism, denitrifier activity, and SADN rates in sulfur-based denitrification reactors is still limited.