Removal of refractory organics and heavy metals in landfill leachate concentrate by peroxi-coagulation process.

Landfill leachate is a complex effluent and it is difficult to deal with. Electrochemical methods have been considered as a promising alternative technology for treatment of landfill leachate with refractory organic contaminants and heavy metals. Peroxi-coagulation (PC) process with iron anode and modified graphite felt cathode was developed for efficient landfill leachate concentrate treatment.

Effects of aqueous phase circulation and catalysts on hydrothermal liquefaction (HTL) of penicillin residue (PR): Characteristics of the aqueous phase, solid residue and bio oil.

Hydrothermal liquefaction (HTL) is a promising thermochemical technology for the treatment of hazardous wastes such as penicillin residue (PR). For the treatment of aqueous waste produced by PR in the HTL process, aqueous phase circulation is an attractive solution, both environmentally and economically. The present study shows that aqueous phase circulation can promote the transfer of organic matter from the aqueous phase to bio-oil.

Catalytic upgrading of penicillin fermentation residue bio-oil by metal-supported HZSM-5.

Antibiotic fermentation residue (AR) is composed of hazardous organic waste produced by the pharmaceutical industry. AR can be effectively converted into bio-oil by fast pyrolysis, but its high nitrogen content limits the prospect of bio-oil as a fuel resource. In order to further reduce the nitrogen content of AR bio-oil, we have examined the catalytic removal of N and O from penicillin fermentation residue (PR) bio-oil under fast pyrolysis conditions.

Preparation of bio-oils by hydrothermal liquefaction (HTL) of penicillin fermentation residue (PR): Optimization of conditions and mechanistic studies.

Response surface methodology (RSM) was used to investigate factors influencing the yield of bio-oil from the hydrothermal liquefaction (HTL) process of penicillin fermentation residue (PR). The reaction mechanism of the HTL was also studied. The hydrolysis of organic compounds in PR was enhanced, and the bio-oil yield increased with an increase of temperature.

Onsite quantifying electron donating capacity of dissolved organic matter.

Electron donating capacity (EDC) of dissolved organic matter (DOM) impacts the redox behaviors of DOM in surface waters, groundwaters, wetlands, sediments and soils but lacks applicable onsite quantification methods. To address these disadvantages, a simple and portable device with pre-injected [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonicacid), ABTS·] was developed that can be used for EDC onsite measurements of DOM in this work. The proposed device and method had better limits of quantification of Trolox (0.

Tradeoff between groundwater arsenite removal efficiency and current production in the self-powered air cathode electrocoagulation with different oxygen reduction pathways.

Naturally occurring arsenic enrichment in aquifers posts a huge threat to drinking water safety. To achieve energy-efficient arsenite [As(III)] removal, a self-powered iron electrocoagulation was developed that coupled iron corrosion anode with oxygen reduction air cathode for simultaneous As(III) oxidation and removal. Activated carbon (AC), which favored the four-electron oxygen reduction reaction (ORR, O+4e+4H→2HO, E = 0.

Improving sludge dewaterability by combined conditioning with Fenton's reagent and surfactant.

The effect of Fenton's reagent combined with dodecyl dimethyl benzyl ammonium chloride (DDBAC) on sludge dewaterability was studied. The capillary suction time (CST) and water content (WC) of sludge cake were used to evaluate sludge dewaterability. Bound water content (W ), extracellular polymeric substance (EPS) concentration, and organic acid concentration in the sludge supernatant were measured to explain the change of dewaterability in the conditioning process.

Multiple factors affect diversity and abundance of ammonia-oxidizing microorganisms in iron mine soil.

Ammonia oxidation by microorganisms is a critical process in the nitrogen cycle. In this study, four soil samples collected from a desert zone in an iron-exploration area and others from farmland and planted forest soil in an iron mine surrounding area. We analyzed the abundance and diversity of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in iron-mining area near the Miyun reservoir using ammonia monooxygenase.

Illumina MiSeq sequencing investigation on the contrasting soil bacterial community structures in different iron mining areas.

Mine activities leaked heavy metals into surrounding soil and may affected indigenous microbial communities. In the present study, the diversity and composition of the bacterial community in soil collected from three regions which have different pollution degree, heavy pollution, moderate pollution, and non-pollution, within the catchment of Chao River in Beijing City, were compared using the Illumina MiSeq sequencing technique. Rarefaction results showed that the polluted area had significant higher bacterial alpha diversity than those from unpolluted area.

Dewaterability of sludge conditioned with surfactant DDBAC pretreatment by acid/alkali.

The potential benefits of surfactant-conditioned sludge dewatering treatment with acid/alkali pretreatment were investigated in this study. The water content of dewatered sludge (W C) and specific resistance of filtration (SRF) were used to evaluate sludge dewaterability. Extracellular polymeric substance (EPS) content, bound water content, zeta potential, and rheological properties were measured to explain the change of dewaterability observed in the conditioning process.