微生物强化处理印染废水的中试研究

以绍兴县综合性印染废水为处理对象,采用混凝一水解酸化一好氧工艺,并且在好氧单元中投加微生物菌剂进行中试研究,探讨了该工艺对印染废水的处理效能。结果表明,投加菌剂后,该系统出水大大改善。投加茵剂前,出水CODl91mg／L,投加菌剂后,出水111mg／L。当该系统高效茵群已形成后,不投加茵剂20天内,该系统仍然可以保持出水CODl21mg／L。当该系统MLSS大量降低后,该系统出水仍然可达120mg／L,此现象说明该系统耐受冲击能力强,且为污泥的减量化研究可能指明了一个新方向。     

Historical trends in the anthropogenic heavy metal levels in the tidal flat sediments of Lianyungang, China

The sedimentation of metals can preserve the historical record of contaminant input from local and regional sources and provide information on the historical changes in regional water and sediment quality. We report the ²¹⁰Pb activities and the heavy metal (Cd, Cr, Cu, Mn, Pb and Zn) depth profiles from sediment cores retrieved in 2010. The mean sedimentation rates of 0.85-1.5 cm/yr are determined by ²¹⁰Pb dating. The sediments in the tidal flat have recorded heavy metal deposition and thus allow the establishment of a connection between the temporal evolution of the heavy metal pollution and the historical changes in the economic development of Lianyungang. The enrichment factors (EF) are calculated to estimate the level of contamination stored in these sediments. The results show that in the studied sites, Cr and Cu display low EF values and are mainly from lithogenic origin. For the other studied trace metals, a great variability in the sedimentary record is observed. Significant anthropogenic enrichment over the last 50 years is revealed at the tidal flat that receives fluvial inputs. Zinc is the element with the highest EF values, followed by the order of Pb > Cd > Mn > Cu and Cr. The temporal variations of the heavy metals peak during the late 1980s to the early 2000s and show a decreasing trend afterward. The pollution intensity of the tidal flat is determined by using EF and the geo-accumulation index (I_geo), which show that, based on the I_geo scale, the tidal flat of Haizhou Bay is unpolluted to moderately polluted.     

电石渣处理煤矿酸性废水技术的研究

利用电石渣对煤矿酸性废水进行处理,达到以废治废的目的。为此对该技术进行研究。在反应停留时间为29 h,pH为6.93时,出水总铁为4.00 mg/L、亚铁为2.01 mg/L、总锰为0.90 mg/L,去除率分别为:总铁:99.04%、亚铁:99.44%、总锰:86.86%。出水指标达GB 20426—2006《煤炭工业污染物排放标准》的要求。     

Speciation of organic phosphorus in a sediment profile of Lake Taihu I: Chemical forms and their transformation

Organic phosphorus(nonreactive P,NRP)is a major component of P in sediments,but information about its chemical forms and dynamic transformation is limited.The chemical forms and dynamic behaviors of NRP in a sediment profile from Lake Taihu,a freshwater and eutrophic lake in China,were investigated.Five forms of NRP in the sediments were extracted based on a chemical fractionation technique,including easily labile NRP(NaHCO3-NRP),reactive metal oxide-bound NRP(HCl-NRP),humic acid-associated NRP(NaOH-NRPHA),fulvic acid-associated NRP(NaOH-NRPFA)and residual NRP(Res-TP).There were notable transformations with increasing sediment depth from the labile NaHCO3-NRP and NaOH-NRP pools to the recalcitrant HCl-NRP and Res-TP pools,which caused the NRP to become increasingly recalcitrant as the early diagenetic processes proceeded.Further analyses showed that the relative changes in contents of organic matter and reactive Fe oxides in the sediment profile triggered a competition for binding NRP fractions and led to the transformation of NRP.The results highlighted the importance of abiotic processes in regulating the diagenesis of organic P and its stability in sediments.     

Exposure to butylated hydroxytoluene compromises endometrial decidualization during early pregnancy

Environmental Science and Pollution Research - Butylated hydroxytoluene (BHT), one of the most widely used synthetic phenolic antioxidants, is a popular food additive. Previous studies have...     

A text mining-based thematic model for analyzing construction and demolition waste management studies

Environmental Science and Pollution Research - Over the years, numerous studies have been conducted to investigate construction and demolition waste (CDW) management problems. However, the massive...     

Review on recent progress in on-line monitoring technology for atmospheric pollution source emissions in China

Emissions from mobile sources and stationary sources contribute to atmospheric pollution in China, and its components, which include ultrafine particles (UFPs), volatile organic compounds (VOCs), and other reactive gases, such as NH₃ and NO_x, are the most harmful to human health. China has released various regulations and standards to address pollution from mobile and stationary sources. Thus, it is urgent to develop online monitoring technology for atmospheric pollution source emissions. This study provides an overview of the main progress in mobile and stationary source monitoring technology in China and describes the comprehensive application of some typical instruments in vital areas in recent years. These instruments have been applied to monitor emissions from motor vehicles, ships, airports, the chemical industry, and electric power generation. Not only has the level of atmospheric environment monitoring technology and equipment been improving, but relevant regulations and standards have also been constantly updated. Meanwhile, the developed instruments can provide scientific assistance for the successful implementation of regulations. According to the potential problem areas in atmospheric pollution in China, some research hotspots and future trends of atmospheric online monitoring technology are summarized. Furthermore, more advanced atmospheric online monitoring technology will contribute to a comprehensive understanding of atmospheric pollution and improve environmental monitoring capacity.     

Research on ammonia emissions characteristics from light-duty gasoline vehicles

In this study, ammonia emissions characteristics of typical light-duty gasoline vehicles were obtained through laboratory vehicle bench test and combined with New European Driving Cycle (NEDC) condition and Worldwide Harmonized Light Vehicles Test Cycle (WLTC) condition. The influence of ambient temperature on ammonia emissions is mainly concentrated in the cold start stage. The influence of ambient temperature on ammonia emission is shown that the ammonia emissions of light-duty gasoline vehicles under ambient temperature conditions (14 and 23°C) are lower than those under low ambient temperature conditions (?7°C) and high ambient temperature conditions (35 and 40°C). The influence of TWC on ammonia emission is shown that ammonia is a by-product of the catalytic reduction reaction of conventional gas pollutants in the exhaust gas in the TWC. Under NEDC operating conditions and WLTC operating conditions, ammonia emissions after the catalyst are 45 times and 72 times that before the catalyst, respectively. In terms of ammonia emissions control strategy research, Pd/Rh combination can reduce NH₃ formation more effectively than catalyst with a single Pd formula. Precise control of the engine's air-fuel ratio and combination with the optimized matched precious metal ratio TWC can effectively reduce ammonia emissions.     

石化企业气体泄漏红外成像检测技术研究进展

介绍了气体泄漏红外成像检测技术的工作原理和分类,综述了国内外相关单位的研究进展,重点分析了国外公司对被动式红外成像检测技术的研究情况,并对技术的发展方向进行了展望。     

Assessing the capacity of biochar to stabilize copper and lead in contaminated sediments using chemical and extraction methods

Because of its high adsorption capacity, biochar has been used to stabilize metals when remediating contaminated soils; to date, however, it has seldom been used to remediate contaminated sediment. A biochar was used as a stabilization agent to remediate Cu- and Pb-contaminated sediments, collected from three locations in or close to Beijing. The sediments were mixed with a palm sawdust gasified biochar at a range of weight ratios (2.5%, 5%, and 10%) and incubated for 10, 30, or 60?days. The performance of the different treatments and the heavy metal fractions in the sediments were assessed using four extraction methods, including diffusive gradients in thin films, the porewater concentration, a sequential extraction, and the toxicity characteristic leaching procedure. The results showed that biochar could enhance the stability of heavy metals in contaminated sediments. The degree of stability increased as both the dose of biochar and the incubation time increased. The sediment pH and the morphology of the metal crystals adsorbed onto the biochar changed as the contact time increased. Our results showed that adsorption, metal crystallization, and the pH were the main controls on the stabilization of metals in contaminated sediment by biochar.