A set up of a modern analytical laboratory for wastewaters from pulp and paper industry

Alloy-Driven Efficient Electrocatalytic Oxidation of Biomass-Derived 5-Hydroxymethylfurfural towards 2,5-Furandicarboxylic Acid: A Review

In recent years, electrocatalysis was progressively developed to facilitate the selective oxidation of biomass-derived 5-hydroxymethylfurfural (HMF) towards the value-added chemical 2,5-furandicarboxylic acid (FDCA). Among reported electrocatalysts, alloy materials have demonstrated superior electrocatalytic properties due to their tunable electronic and geometric properties. However, a specific discussion of the potential impacts of alloy structures on the electrocatalytic HMF oxidation performance has not yet been presented in available Reviews. In this regard, this Review introduces the most recent perspectives on the alloy-driven electrocatalysis for HMF oxidation towards FDCA, including oxidation mechanism, alloy nanostructure modulation, and external conditions control. Particularly, modulation strategies for electronic and geometric structures of alloy electrocatalysts have been discussed. Challenges and suggestions are also provided for the rational design of alloy electrocatalysts. The viewpoints presented herein are anticipated to potentially contribute to a further development of alloy-driven electrocatalytic oxidation of HMF towards FDCA and to help boost a more sustainable and efficient biomass refining system.

One-step fabrication of bifunctional self-assembled oligopeptides anchored magnetic carbon nanoparticles and their application in copper (II) ions removal from aqueous solutions

Copper ion (Cu (II)) pollution has attracted much attention due to its remarkable toxic domino effect at excess amount. Efficient Cu (II) ions removal is thus a prerequisite for wastewater recycling. Herein, we present a facile and environmentally benign strategy to fabricate thiol (SH)-functionalized Fe₃O₄@C nanoparticles (denoted as Fe₃O₄@C-SH NPs) based on one-step self-assembling of a bifunctional oligopeptide with a sequence of Cys-Lys-Cys-Lys-Cys-Lys (CK-VI) for highly efficient removal of copper ions (Cu (II)) in aqueous solutions. Under the physiological conditions, CK-VI readily self-organized into a robust and tailor-made functional monolayer predominately composed of well-packed β-sheets on the surface of Fe₃O₄@C NPs with their thiol groups standing on the outermost layer. The resulting Fe₃O₄@C-SH NPs containing abundant thiol active sites exhibited excellent adsorption capacity (up to 28.8 mg g^-1) and selectivity for Cu (II) ions over coexisting ions. Compared with other covalent grafting methods with multistep processes and in harsh conditions, the proposed oligopeptides assembly-based coating method makes it possible to rapidly fabricate the Fe₃O₄@C-SH NPs in a simple mild one-step aqueous process with low cost. The current study provides facile and environmentally friendly approaches to rapidly tailor multifunctional surfaces of NPs for various toxic metal ions removal from wastewater.

Bio-inspired writable multifunctional recycled paper with outer and inner uniform superhydrophobicity

One kind of multifunctional superhydrophobic recycled paper from the secondary use of waste paper has been prepared successfully with wonderful self-cleaning, anti-fouling and oil absorption abilities.

Novel environmental analytical system based on combined biodegradation and photoelectrocatalytic detection principles for rapid determination of organic pollutants in wastewaters

This work describes the development of a novel biofilm reactor-photoelectrocatalytic chemical oxygen demand (BFR-PeCOD) analytical system for rapid online determination of biodegradable organic matters (BOMs). A novel air bubble sample delivery approach was developed to dramatically enhance the BFR's biodegradation efficiency and extend analytical linear range. Because the air bubble sample delivery invalidates the BOD quantification via the determination of oxygen consumption using dissolved oxygen probe, the PeCOD technique was innovatively utilized to resolve the BOD quantification issue under air bubble sample delivery conditions. The BFR was employed to effectively and efficiently biodegrade organic pollutants under oxygen-rich environment provided by the air bubbles. The BOD quantification was achieved by measuring the COD change (Δ[COD]) of the original sample and the effluent from BFR using PeCOD technique. The measured Δ[COD] was found to be directly proportional to the BOD5 values of the original sample with a slope independent of types and concentrations of organics. The slope was used to convert Δ[COD] to BOD5. The demonstrated analytical performance by BFR-PeCOD system surpasses all reported systems in many aspects. It has demonstrated ability to near real-time, online determining the organic pollution levels of wide range wastewaters without the need for dilution and ongoing calibration. The system possesses the widest analytical liner range (up to 800 mg O2 L(-1)) for BOD analysis, superior long-term stability, high accuracy, reliability, and simplicity. It is an environmentally friendly analytical system that consumes little reagent and requires minimal operational maintenance.

BOD biosensors for pulp and paper industry wastewater analysis

INTRODUCTION

Two semi-specific microbial biosensors were constructed for the analysis of biochemical oxygen demand (BOD) in high-cellulose-content pulp and paper industry wastewaters. The biosensors were based on living cells of Bacillus subtilis and Paenibacillus sp. immobilized in an agarose gel matrix. Semi-specific microorganisms were isolated from various samples (decaying sawdust and rabbit manure) and were chosen based on their ability to assimilate cellulose.

MATERIALS & METHODS

The biosensors were calibrated with the Organization for Economic Cooperation and Development synthetic wastewater, and measurements with different wastewaters were conducted.

RESULTS

The response time of biosensors using the steady-state method was 20-25 min, and the service life of immobilized microorganisms was 96 days. Detection limit was 5 mg/l of BOD(7) while linear ranges extended up to 55 and 50 mg/l of the BOD(7) for B. subtilis- and Paenibacillus sp.-based biosensors, respectively. Repeatability and reproducibility of both biosensors were within the limits set by APHA-less than 15.4%. In comparison, both biosensors overestimated the BOD(7) values in paper mill wastewaters and underestimated the BOD(7) in aspen pulp mill wastewater.

CONCLUSIONS

The semi-specific biosensors are suitable for the estimation of organic pollution derived from cellulose, while the detection of pollution derived from tannins and lignins was minor. Better results in terms of accuracy and repeatability were gained with Paenibacillus sp. biosensor.

Effects of fungicides mancozeb and dinocap on carbon and nitrogen mineralization in soils

In our study, effects of fungicides mancozeb and dinocap on C and N mineralization were measured in arable and grassland soil. The soils were treated with these fungicides at the application and 10 times lower doses and then incubated at 20 degrees C for 2 weeks. Carbon mineralization (basal and substrate-induced respiration) and nitrogen mineralization (potential ammonification and nitrification) were evaluated 1 and 14 days after the treatment. After 14 days, ammonification was decreased to 48% and 83% at dinocap application dose in arable and grassland soil, respectively. Application dose of mancozeb caused significant decrease of nitrification to 11.2% and 5.6% in arable and grassland soil, respectively. Basal respiration and substrate-induced growth were rather stimulated by fungicides, especially at lower application doses. To conclude, potential risk may exist to soil microorganisms and their activities in soils treated routinely by mancozeb or dinocap.

Fast characterization of non domestic load in urban wastewater networks by UV spectrophotometry

Urban wastewater treatment plant efficiency, as well as biosolid quality, depends on urban wastewater quality, which can be affected by non domestic discharges (industrial, commercial etc.). The characterization of wastewater quality and non domestic discharge is complex, expensive and time consuming. However, these discharges must be controlled and reduced if possible. The development of a simple and fast methodology, namely based on alternative methods such as UV spectrophotometry, has been carried out and applied to different areas of a medium sized town of Southern Québec (Canada). Several autosamplers and on line/on site measurements have been used in critical control points of the network areas, for a dry weather campaign in four areas (industrial, commercial, hospital and university). The flow rate study, completed by the exploitation of conductivity measurements and the qualitative examination of UV spectra allows the discrimination of non domestic loads and their variability study from one point to another. The identification of critical discharges and organic shock loads has been possible with low investment, and mitigation actions have been proposed.