Synergetic decolorization and deodorization of sludge protein foaming solution by 60Co γ-ray irradiation/H2O2 oxidation

Sludge protein foaming solution was effectively decolorized and deodorized by gamma irradiation in the presence of hydrogen peroxide. The existence of a synergetic effect on the decolorization and the deodorization was demonstrated by means of UV/vis spectrophotometry, chemical, and sensory analyses every 14 days during 98 days of storage. Furthermore, the foamability was measured using the Ross–Miles method. Results showed that color, odor, and foamability of irradiated samples under hydrogen peroxide oxidation were significantly improved. Sensory evaluation indicated that irradiated samples under hydrogen peroxide oxidation were better than nonirradiated samples in odor, and color. Finally, a preliminary cost analysis revealed that ⁶⁰Co γ-ray/H₂O₂ process was more cost-effective than the H₂O₂ alone.     

A signal-amplified whole-cell biosensor for sensitive detection of Hg2+ based on Hg2+-enhanced reporter module

A signal-amplified mercury sensing biosensor with desired sensitivity was developed through firstly using the GFP mutant with fluorescence increasing response towards Hg²⁺ as the reporter module. The developed biosensor showed response for Hg²⁺ in a relatively wide range of 1–10,000 nmol/L, and the detection limit was improved one or two orders of magnitude in comparison with most metal-sensing biosensors in similar constructs. In addition, the biosensor could distinguish Hg²⁺ easily from multiple metal ions and displayed strong adaptability to extensive pH conditions (pH 4.0–10.0). More importantly, the developed biosensor was able to provide an initial assessment of Hg²⁺ spiked in the environmental water with the recoveries between 85.70% and 112.50%. The signal-amplified strategy performed by the modified reporter module will be widely applicable to many other whole-cell biosensors, meeting the practical requirements with sufficient sensing performance.     

柴油发电机房在职业卫生评价中的关键点分析

针对柴油发电机组产生的职业病危害因素及危害程度在评价报告中常常被评价人员忽略这一现状,结合柴油发电机房存在的主要职业病危害因素及特点进行分析,得出柴油发电机房在职业卫生评价工作中的关键点,以方便评价人员应用。     

Environmental geochemical characteristics of rare-earth elements in surface waters in the Huainan coal mining area,Anhui Province,China

Environmental Geochemistry and Health - This study investigated the environmental geochemical characteristics of rare-earth elements (REEs) in surface waters in the Huainan mining area, Anhui...     

Can China achieve food security through the development of irrigation?

Regional Environmental Change - China faces the dual challenge of water scarcity and food security with continued population growth. This paper explores methods to meet that demand without...     

A TiO2/crosslinked carboxymethyl starch composite for high-efficiency adsorption and photodegradation of cationic golden yellow X-GL dye

In this paper, a crosslinked carboxymethyl starch (CCMS) was prepared with corn starch as the raw material, epichlorohydrin as the crosslinking agent, and chloroacetic acid as the etherifying agent through a series of crosslinking, alkalization, and etherification reactions, respectively. Nano-TiO₂ was loaded onto the surface of the CCMS by the sol-gel method to obtain a TiO₂/CCMS composite. The TiO₂/CCMS composite was characterized by XPS, XRD, SEM, and BET. XPS showed that the surface chemical composition of the TiO₂/CCMS composite material contained titanium; XRD diffraction patterns indicated that the crystal form of the TiO₂/CCMS composite was a combination of the CCMS and anatase TiO₂. The surface morphology obtained by SEM showed that there were nano-TiO₂ particles on the surface of the CCMS. The specific surface area of the TiO₂/CCMS composite was larger than that of CCMS. The adsorption-photodegradation performance of the TiO₂/CCMS composite was also studied under UV irradiation, and the results showed that significant adsorption-photodegradation synergies occurred.

     

Decomplexation of Cr(III)-EDTA and simultaneous abatement of total Cr by photo-oxidation: efficiency and in situ reduction of intermediate Cr(VI)

Environmental Science and Pollution Research - Most prevailing processes are incapable of removing Cr(III)-organic complexes efficiently and facing the problem of in-process formation of highly...     

Waste recombinant DNA: Effectiveness of thermo-treatment to manage potential gene pollution

Heating at 100 °C for 5–10 min is a common method for treating wastewater containing recombinant DNA in many bio-laboratories in China. In this experiment, plasmid pET-28b was used to investigate decay efficiency of waste recombinant DNA during thermo-treatment. The results showed that the decay half-life of the plasmid was 2.7–4.0 min during the thermo-treatment, and even heating for 30 min the plasmids still retained some transforming activity. Low pH promoted the decay of recombinant DNA, but NaCl, bovine serum albumin and EDTA, which existed in the most wastewater from bio-laboratories, protected DNA from degradation. Thus, the decay half-life of plasmid DNA may be longer than 2.7–4.0 min practically. These results suggest that the effectiveness of heating at 100 °C for treating waste recombinant DNA is low and a gene pollution risk remains when those thermo-treated recombinant DNAs are discharged into the environment. Therefore other simple and effective methods should be developed.     

Study on mechanics of crowd jam based on the cusp-catastrophe model

Some characteristics of crowd jam like the phenomena of discontinuous jumping in reality are hard to be explained by the equations governing pedestrians. The catastrophe theory can explain these characteristics. A cusp-catastrophe model is developed to analyze the mechanics of crowd jam by drawing graphs for a cusp-catastrophe model of crowd, the bifurcation set and the projection of catastrophe model. Meanwhile, the critical density and the critical velocity are derived. It is concluded that the cusp model is a more efficient predictor than the linear model or the equations governing pedestrians and is reasonably realistic for dense crowd flow scenarios.