Enhanced catalytic degradation of aqueous doxycycline (DOX) in Mg-Fe-LDH@biochar composite-activated peroxymonosulfate system: Performances, degradation pathways, mechanisms and environmental implications

Impact of heavy metals on the formation and properties of solvable microbiological products released from activated sludge in biological wastewater treatment.

Lanthanum-iron incorporated chitosan beads for adsorption of phosphate and cadmium from aqueous solutions

Dynamic relationship between dissolved organic matter and soluble microbial products during wastewater treatment

Biological treatment remains one of the most eco-friendly and cost-effective techniques to eliminate pollutants from wastewater in spite of the development of other technologies such as chemical treatment methods and advanced oxidation processes. This paper discusses briefly the main features and recent advances of wastewater treatment (WT). Some future trends are also viewed. Membrane Bioreactor (MBR), Moving Bed Bioreactor (MBBR), and Fixed Bed Bioreactors (FBBR) are largely employed techniques in WT particularly for industrial uses with an elevated biochemical oxygen demand charge like food and beverages, dairy, chemical, leachate and others. Integrations of minutely anaerobic and aerobic methods importantly improved the elimination of specific and non-specific in vitro toxicities. Therefore, optimizing biological WT may conduct to a considerably ameliorated detoxification. Surplus sludge treatment and disposal are regarded as an increasing defy for wastewater treatment plants (WTTPs) because of economic, environmental and regulatory elements. There is thus a fundamental need in expanding procedures for decreasing sludge generation in biological WT processes. Great attention for minimizing sludge formation occurs following procedures founded on mechanisms of lysis-cryptic growth, uncoupling metabolism, maintenance metabolism, and bacterivorous predation. On the other hand, heavy metals presence in wastewater still constitute a handicap for large acceptance of this technology based on cultivating bacteria for organic matter removal.

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Reviviscence of Biological Wastewater Treatment – A Review

Long-term impact of heavy metals on the performance of biological wastewater treatment processes during shock-adaptation-restoration phases.

Lanthanum modified zeolite (LMZ) has been proven to be an effective inactivation agent for lake internal phosphorus load control. However, its performance in the co-sequestration of P and heavy metal is still unclear. Thus, simultaneous adsorption of phosphate and zinc by LMZ was investigated in this study, and its co-inactivation performance in sediment was also verified. Separate adsorption capacities of LMZ for phosphate and zinc were 2.31 and 0.367 mmol/g, respectively. In co-adsorption scenario, removal rate of zinc (0.15 mmol/L) increased from 73.53 to 84.60% when co-existing phosphate increased from 0.097 to 0.48 mmol/L (pH 6.5), while zinc had an inapparent impact on phosphate adsorption. Furthermore, an increase of background NaCl concentration in the system inhibited zinc removal by 25%, indicating that part of zinc was physically adsorbed by the zeolite fraction of LMZ. XPS and Raman spectra suggested that phosphate in the simultaneous adsorption system was innerspherically adsorbed by lanthanum oxide component of LMZ, while zinc was adsorbed by forming both outer-sphere complex and inner-sphere complex. Part of zinc could chelate with the adsorbed phosphate, forming phosphate bridged ternary complex and enhancing zinc removal. Finally, a lab-scale inactivation experiment showed that simultaneous stabilization of P and zinc in sediment could be achieved by dosing 5% weight percentage LMZ, making it a promising inactivation agent in the future.

Simultaneous adsorption of phosphate and zinc by lanthanum modified zeolite

Polycyclic aromatic hydrocarbons (PAHs) are key organic pollutants in the environment that pose threats to the ecosystem and human health. The degradation of high molecular weight (HMW) PAHs by enriched bacterial consortia has been previously studied, while the involved metabolisms and microbial communities are still unclear and warrant further investigations. In this study, five bacterial consortia capable of utilizing different PAHs (naphthalene, anthracene, and pyrene) as the sole carbon and energy sources were enriched from PAH-contaminated soil samples. Among the five consortia, consortium TC exhibited the highest pyrene degradation efficiency (91%) after 19 d of incubation. The degradation efficiency was further enhanced up to 99% by supplementing yeast extract. Besides, consortium TC showed tolerances to high concentrations of pyrene (up to 1000 mg/L) and different heavy metal stresses (including Zn2+, Cd2+, and Pb2+). The dominant genus in consortium TC, GS, and PL showing relatively higher degradation efficiency for anthracene and pyrene was Pseudomonas, whereas consortium PG and GD were predominated by genus Achromobacter and class Enterobacteriaceae, respectively. Consortium TC, as a highly efficient HMW PAH-degrading consortium, could be applied for synergistic biodegradation of HMW PAHs and in situ bioremediation of the sites contaminated with both PAHs and heavy metals.

Dongqi Wang

Papers

Long-term impact of heavy metals on the performance of biological wastewater treatment processes during shock-adaptation-restoration phases.

Simultaneous adsorption of phosphate and zinc by lanthanum modified zeolite

Biodegradation performance and diversity of enriched bacterial consortia capable of degrading high-molecular-weight polycyclic aromatic hydrocarbons