Cheng-Jun Zhu

Bio: Cheng-Jun Zhu is an academic researcher from Nanjing University. The author has contributed to research in topics: Phthalic acid & Terephthalic acid. The author has an hindex of 4, co-authored 8 publications receiving 213 citations.

Microbial PAH-Degradation in Soil: Degradation Pathways and Contributing Factors

Abstract: Adverse effects on the environment and high persistence in the microbial degradation and environmental fate of polycyclic aromatic hydrocarbons (PAHs) are motivating interest. Many soil microorganisms can degrade PAHs and use various metabolic pathways to do so. However, both the physio-chemical characteristics of compounds as well as the physical, chemical, and biological properties of soils can drastically influence the degradation capacity of naturally occurring microorganisms for field bioremediation. Modern biological techniques have been widely used to promote the efficiency of microbial PAH-degradation and make the biodegradation metabolic pathways more clear. In this review microbial degradation of PAHs in soil is discussed, with emphasis placed on the main degradation pathways and the environmental factors affecting biodegradation.

Degradability of five aromatic compounds in a pilot wastewater treatment system

Abstract: Purified terephthalic acid-manufacturing wastewater was treated aerobically with the microbial fusant Fhhh in the carrier activated sludge process at a pilot wastewater treatment plant. Biodegradability of p-toluic acid (p-Tol), benzoic acid (BA), 4-carboxybenzaldehyde (4-CBA), phthalic acid (PA) and terephthalic acid (TA) was monitored. The TOC and COD loading rate of suspended solids (SS) in the sludge were 0.53 g TOC g SS−1 d−1 and 1.79 g COD g SS−1 d−1, respectively. There was significant positive correlation (P PA>4-CBA>TA>p-Tol. The prospect of using MnP-SA to predict the removal rate for the five aromatics is discussed.

Toxicity of pharmaceutical wastewater on male reproductive system of Mus musculus.

Abstract: This study reports on the toxic effects of 35-days intragastric perfusion of pharmaceutical wastewater on the male reproductive system of Mus musculus. Flow cytometric analyses and staining with fluorescein diacetate (FDA) and propidium iodide (PI) were used to assess the toxicity on spermatogenic cells. Significant depletions in the relative percentages of elongated spermatid (HC), diploid spermatogonia (2C), and S-phase cells were observed. These alterations in different germ cell populations were reflected in the various germ cell ratios. The ratios of 1C : 4C and HC : 2C showed a significant decline after pharmaceutical wastewater treatment, while the 4C : 2C and 1C : 2C ratios increased significantly. FDA and PI staining displayed reduced viability of spermatogenic cells in wastewater treated group. Statistically significant percentages of sperm abnormalities showed the genotoxic potential of this pharmaceutical wastewater. Testicular histopathological studies of treated animals revealed expansion of...

Pilot regulation of MnP-SA for treating PTA wastewater.

Abstract: In the pilot study of treating the purified terephthalic acid (PTA) wastewater with the functional Strain Fhhh in the carrier activated sludge process (CASP), the ratio of COD: TN: TP and the concentrations of Cu, Mn, Se and Zn were controlled to improve the manganese peroxidase (MnP) levels for increasing the treatment efficiency. When the ratio of COD: TN: TP was 100: 0.36: 0.15 and the concentrations of Cu, Mn, Se and Zn were 0.54, 5.07, 0.00 and 0.08 mg/L, the MnP specific activity (MnP-SA) reached 689 U/L, and the sludge loading rate to COD(SLRC) was 1.09 d(-l), which was 4--7 fold of that in other processes reported. The data indicated that improving MnP level could enhance the degradability of Fhhh. And the potentials of Fhhh and CASP will be also discussed in this paper.

PAH diagnostic ratios for the identification of pollution emission sources

Abstract: Polycyclic aromatic hydrocarbon (PAH) diagnostic ratios have recently come into common use as a tool for identifying and assessing pollution emission sources. Some diagnostic ratios are based on parent PAHs, others on the proportions of alkyl-substituted to non-substituted molecules. The ratios are applicable to PAHs determined in different environmental media: air (gas + particle phase), water, sediment, soil, as well as biomonitor organisms such as leaves or coniferous needles, and mussels. These ratios distinguish PAH pollution originating from petroleum products, petroleum combustion and biomass or coal burning. The compounds involved in each ratio have the same molar mass, so it is assumed they have similar physicochemical properties. Numerous studies show that diagnostic ratios change in value to different extents during phase transfers and environmental degradation. The paper reviews applications of diagnostic ratios, comments on their use and specifies their limitations.

Bioremediation of soils contaminated with polycyclic aromatic hydrocarbons, petroleum, pesticides, chlorophenols and heavy metals by composting: Applications, microbes and future research needs

Abstract: Increasing soil pollution problems have caused world-wide concerns. Large numbers of contaminants such as polycyclic aromatic hydrocarbons (PAHs), petroleum and related products, pesticides, chlorophenols and heavy metals enter the soil, posing a huge threat to human health and natural ecosystem. Chemical and physical technologies for soil remediation are either incompetent or too costly. Composting or compost addition can simultaneously increase soil organic matter content and soil fertility besides bioremediation, and thus is believed to be one of the most cost-effective methods for soil remediation. This paper reviews the application of composting/compost for soil bioremediation, and further provides a critical view on the effects of this technology on microbial aspects in contaminated soils. This review also discusses the future research needs for contaminated soils.

Pollution from drug manufacturing: review and perspectives.

Abstract: As long ago as the sixteenth century, Paracelsus recognized that 'the dose makes the poison'. Indeed, environmental concentrations of pharmaceuticals excreted by humans are limited, most importantly because a defined dose is given to just a fraction of the population. By contrast, recent studies have identified direct emission from drug manufacturing as a source of much higher environmental discharges that, in some cases, greatly exceed toxic threshold concentrations. Because production is concentrated in specific locations, the risks are not linked to usage patterns. Furthermore, as the drugs are not consumed, metabolism in the human body does not reduce concentrations. The environmental risks associated with manufacturing therefore comprise a different, wider set of pharmaceuticals compared with those associated with risks from excretion. Although pollution from manufacturing is less widespread, discharges that promote the development of drug-resistant microorganisms can still have global consequences. Risk management also differs between production and excretion in terms of accountability, incentive creation, legal opportunities, substitution possibilities and costs. Herein, I review studies about industrial emissions of pharmaceuticals and the effects associated with exposure to such effluents. I contrast environmental pollution due to manufacturing with that due to excretion in terms of their risks and management and highlight some recent initiatives.

Bioremediation mechanisms of combined pollution of PAHs and heavy metals by bacteria and fungi: A mini review.

Abstract: In recent years, knowledge in regard to bioremediation of combined pollution of polycyclic aromatic hydrocarbons (PAHs) and heavy metals by bacteria and fungi has been widely developed. This paper reviews the species of bacteria and fungi which can tackle with various types of PAHs and heavy metals entering into environment simultaneously or successively. Microbial activity, pollutants bioavailability and environmental factors (e.g. pH, temperature, low molecular weight organic acids and humic acids) can all affect the bioremediation of PAHs and heavy metals. Moreover, this paper summarizes the remediation mechanisms of PAHs and heavy metals by microbes via elucidating the interaction mechanisms of heavy metals with heavy metals, PAHs/PAHs metabolites with PAHs and PAHs with heavy metals. Based on the above reviews, this paper also discusses the potential research needs for this field.

Microbial communities to mitigate contamination of PAHs in soil—possibilities and challenges: a review

Abstract: Background, aim, and scope Although highly diverse and specialized prokaryotic and eukaryotic microbial communities in soil degrade polycyclic aromatic hydrocarbons (PAHs), most of these are removed slowly. This review will discuss the biotechnological possibilities to increase the microbial dissipation of PAHs from soil as well as the main biological and biotechnological challenges.