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With the rapid development of industrialization and human civilization, the soil polluted by heavy, toxic lead is becoming increasingly severe worldwide. Thus, it is imperative to control soil pollution due to lead. In this paper, the background, status, and harm of lead-polluted soil were introduced, and the source, mode of occurrence, and extraction of lead from the soil were depicted in detail. Based on the current soil remediation technology, three major methods, namely, physical, chemical, and bioremediation, have been systematically reviewed, and their advantages and disadvantages from the aspects of efficiency, applicability, and economy were evaluated and compared. Results reveal that the most preferred remediation method for heavy, toxic, lead-contaminated soil is chemical remediation. The chemical leaching and immobilization/stabilization methods were subsequently introduced in detail, and the remediation mechanism, effect, applicability, and application prospect of the different types of eluants and curing agents were evaluated and discussed. Finally, the prospect of cleaning and efficient remediation of heavy, toxic, lead-contaminated soil was presented. The restoration should minimize the damage to the soil. For the heavy, lead-contaminated soil, the development of the joint remediation technology is the potential development direction. The mechanism of soil remediation and directional remediation should be determined as soon as possible. Meanwhile, the research and development of multifunctional composite materials should be strengthened.

Three typical ferroalloy slags, namely, silicon–manganese, nickel–iron, and chrome–iron slags, are produced in large quantities as by-products. This is because they are not efficiently utilized, which creates lots of pressure on environmental capacity and development of enterprises. At present, comprehensive utilization of ferroalloy slags is mainly concentrated on the traditional building materials such as cement and concrete. Although the construction industry consumes a large amount of ferroalloy slags, their high-energy consumption and relatively limited product value limit their maximum utilization. With the increasing market demand and improvement of energy and environmental awareness, the research on rational utilization of ferroalloy slags has been changing from its use as raw materials in traditional building materials to use as raw materials to produce new products with comparatively lower energy consumption and higher product value, which explores the possibility of slag reutilization in other fields. Based on the quality requirements of different ferroalloys, there are significant differences in the requirements of the raw materials and different smelting processes. As a result, different types of ferroalloy slags, having different physical and chemical properties, are produced. This study briefly presented the uses of the silicon–manganese, nickel–iron, and chrome–iron slags. It also showed how to classify these three typical ferroalloy slags. The differences of their chemical and mineral phase composition were also systematically analyzed in this study, which discussed different properties of different slags and provided the basic theoretical guidelines on how to efficiently utilize these slags. This study also emphatically summarized the latest domestic and foreign research advancements about their utilization in traditional building materials such as cement and concrete, and in new functional materials such as geopolymer, inorganic mineral fiber, microcrystalline glass, artificial light aggregate, and refractory materials required to build walls and as alternative raw materials to prepare functional ceramics. Based on the results of this study, we summarized the advantages and disadvantages of using the abovementioned ferroalloy slags as raw materials to generate different materials, and put forward the prospects for its future utilization direction and approach. The study also guided the key development areas for further studying and breaking through the bottleneck of the main utilization mode, formulating and improving the relevant application and pollution control standards, and developing and promoting high value-added products.

In order to study toxicological effects of perfluorononanoic acid (PFNA), perfluorooctane sulfonate (PFOS), and their mixtures (PFNA/PFOS) on Daphnia magna (D. magna), a suite of comprehensive toxicity tests were conducted, including a 48-h acute toxicity test, a 21-day chronic test, a feeding experiment, and a biomarker assay. D. magna were exposed to aqueous solutions of PFNA and PFOS (alone and in combination) at concentrations ranging from 0.008 to 5 mg/L. The survival, growth, and reproduction of D. magna were monitored over a 21-day life cycle. The biomarkers, including acetylcholinesterase (AChE), superoxide dismutase (SOD), and catalase (CAT) activities, were determined after seven days of exposure. PFOS was more toxic than PFNA based on the results of the acute toxicity test. Perfluorinated compounds (PFCs) inhibited both growth and reproduction of D. magna during the testing period. The ingestion rates and the biomarkers, including AChE, SOD, and CAT activities, were significantly inhibited by PFCs in most cases. Moreover, the combined effects related to the growth and reproduction showed the antagonistic effects of PFCs.

The freshwater fish Carassius auratus was chosen as an experimental subject, and their hepatic biochemical responses to the medium-term exposure of Benzo(k)fluoranthene (BkF) alone and in combination with PCB118 and dichlorodiphenyltrichloroethane (DDT) were investigated by measuring the reduced glutathione (GSH), glutathione S-transferase (GST), and thiobarbituric acid reactive substances (TBARS), to assess sublethal effects. The hepatic GSH content was significantly inhibited by organic pollutants, alone and in mixtures, while the TBARS content was significantly induced after three days of exposure. Bell-shaped concentration-response charts of GST activities were obtained. Significant dose-response relationships were found for hepatic GSH and TBARS contents of all concentrations and for the GST activity, except at the highest concentration. The GSH content, GST activity, and TBARS content in Carassius auratus were confirmed as useful biomarkers of exposure to organic pollutions.

This paper addresses a comprehensive and comparative study of six phytochemical extraction methods for triterpenes from the fruiting body of Ganoderma spp. Quantitative analysis of extracts was performed by HPLC with photodiode array detection. In general, pressurized liquid extraction and microwave-assisted extraction under optimized conditions produce better yields, and the former also significantly reduces the total time of extraction and manipulation of a sample, as well as the amount of solvent used in comparison with conventional soxhlet, reflux, ultrasonic, and methanol--CO2 supercritical fluid extractions. Based on the improved extraction protocol, the fingerprinting profiles for two species of Lingzhi were established using the consistent chromatographic features of 12 authentic samples. Eleven common peaks of ganoderic/ganoderenic acids were identified using LC-ESI-MS-MS. These specific triterpene groups were adopted as chemical markers for Lingzhi. Using chemometric analysis, the developed fingerprinting was successfully applied to differentiate between the two species under the Ganoderma genus and is applicable as a method for quality evaluation of this valuable medicinal fungus and its related proprietary products. [ABSTRACT FROM AUTHOR]

Objective To identify the bacteria tolerating chlorinated anilines and to study the biodegradability of o-chloroaniline and its coexistent compounds. Methods Microbial community of complex bacteria was identified by plate culture observation techniques and Gram stain method. Bacterial growth inhibition test was used to determine the tolerance of complex bacteria to toxicant. Biodegradability of chlorinated anilines was determined using domesticated complex bacteria as an inoculum by shaking-flask test. Results The complex bacteria were identified, consisting of Xanthomonas, Bacillus alcaligenes, Acinerobacrer; Pseudomonas, and Actinomyceraceae nocardia. The obtained complex bacteria were more tolerant to o-chloroaniine than mixture bacteria in natural river waters. The effects of exposure concentration and inoculum size on the biodegradability of o-chloroaniline were analyzed, and the biodegradation characteristics of single o-chloroaniline and 2, 4-dichloroaniline were compared with the coexistent compounds. Conclusion The biodegradation rates can be improved by decreasing concentration of compounds and increasing inoculum size of complex bacteria. When o-chloroaniline coexists with aniline, the latter is biodegraded prior to the former, and as a consequence the metabolic efficiency of o-chloroaniline is improved with the increase of aniline concentration. Meanwhile, when o-chloroaniline coexists with 2,4-dichioroaniline, the metabolic efficiency of 2,4-dichloroaniline is markedly improved. [ABSTRACT FROM AUTHOR]

Objective To measure the acute toxicity of halogenated benzenes to bacteria in natural waters and to study quantitative relationships between the structure and activity of chemicals. Methods The concentration values causing 50% inhibition of bacteria growth (24h-IC50) were determined according to the bacterial growth inhibition test method. The energy of the lowest unoccupied molecular orbital and the net charge of carbon atom of 20 halogenated benzenes were calculated by the quantum chemical MOPAC program. Results The log1/IC50 values ranged from 4.79 for 2,4-dinitrochlorobenzene to 3.65 for chlorobenzene. A quantitative structure-activity relationship model was derived from the toxicity and structural parameters: log1/IC50=-0.531(ELUM0)+1.693(Qc)+0.163(logP)+3.375. This equation was found to fit well (r2=0.860, s=0.106), and the average percentage error was only 1.98%. Conclusion Halogenated benzenes and alkyl halogenated benzenes are non-polar narcotics, and have hydrophobicity-dependent toxicity. The halogenated phenols and anilines exhibit a higher toxic potency than their hydrophobicity, whereas 2,4-dinitrochlorobenzene is electrophile with the halogen acting as the leaving group. [ABSTRACT FROM AUTHOR]

Objective To study the correlation of toxicity with biodegradability (BODT) in order to promote QSBR development and understand the degradation mechanism. Methods Toxicity of substituted phenols to river bacteria was determined by the turbidities that were measured using a spectrophotometer (UV-190) at 530 nm against a blank control. The biodegradability of substituted phenols was expressed as BODT and the DO concentrations were determined by the iodometric titration method. Results The BODT and toxicity(log 1/IC50) of 12 substituted phenols to bacteria from the Songhua River were determined respectively. The correlation of biodegradability with toxicity was developed: BODT=8.2 1 (±2.22) pKa -32.44 (±8.28) log 1/IC50 +89.04 (±38.20), n=12, R²=0.791, R²(adj)=0.745, SE=9.134, F=17.066, P=0.001. Conclusion The BODT of substituted phenols was influenced by their toxicity and the ionization constant pKa. The stronger the toxicity, the less readily the compound was degraded by river bacteria. [ABSTRACT FROM AUTHOR]

Objective To measure the 96h-LC50 values of 32 substituted benzenes to the carp and to study the relationship between quantitative structure-activity and structural parameters of chemicals. Methods The acute toxicity values of 32 substituted benzenes to the carp were determined in a semistatic test. The energy of the lowest unoccupied molecular orbital, and the highest occupied molecular orbital, the dipole moment and the molecular weight of substituted benzenes were calculated by the quantum chemical method MOPAC6.0. Results The range of the toxicity of studied compounds was broad, and the most toxic compound was pentachlorophenol, while the least toxic compound was 4-methylaniline. By the stepwise regression analyses, a series of Quantitative structure-activity relationships (QSAR) equations were derived from all compounds and subclasses. The equation log1/LC50=0.759logP +2.222 (R² (adj)=0.818) was found to fit well and the average predicted percentage error was 6.16%. Conclusion The toxicity of anilines and phenols to the carp could be modeled well by logP alone, whereas the toxicity of the halogenated benzenes and nitrobenznes not containing hydroxyl or amino group can be controlled by hydrophobic and electronic factors. [ABSTRACT FROM AUTHOR]

Abstract: The IC[sub 50] values of 20 nitroaromatics were determined by the activity of ATPase of carp (Cyprinus carpio) kidney in vitro, and used to develop the quantitative structure activity relationship (QSAR) with 6 descriptors of 1X[sup v], Sigma Sigma[sup -], I, [sup 1]Ka, E[sub LUMO]), logP. A best equation was obtained by multiple regression analysis - log IC[sub 50] = 1.306 Sigma Sigma[up -] + 0.657I + 0.584E[sub LUMO] + 2.852(r = 0. 925). Sigma Sigma[sup -] is the sum of substituent constants. I is the indicator variable. E[sub LUMO] is the energy of the lowest unoccupied orbital. Results showed that the Sigma Sigma[sup -], I and E[sub LUMO]) were closely correlated with toxicity of nitroaromatics. Some toxicity mechanisms by nitmaromatics are also discussed in this paper. [ABSTRACT FROM AUTHOR]