Particulate and dissolved phosphorus chemical separation and phosphorus release from treated dairy manure

In confined animal feeding operations, liquid manure systems present special handling and storage challenges because of the large volume of diluted wastes. Water treatment polymers and mineral phosphorus (P) immobilizing chemicals [AI2(SO4)3 x 18H2O, FeCl3-6H2O, and Class C fly ash] were used to determine particulate and dissolved reactive phosphorus (DRP) reduction mechanisms in high total suspended solid (TSS) dairy manure and the P release from treated manure and amended soils. Co-application exceeded the aggregation level achieved with individual manure amendments and resulted in 80 and 90% reduction in metal salt and polymer rates, respectively. At marginally effective polymer rates between 0.01 and 0.25 g L(-1), maximal aggregation was attained in combination with 1 and 10 g L(-1) of aluminum sulfate (3 and 30 mmol Al3+ L(-1)) and iron chloride (3.7 and 37 mmol Fe3+ L(-1)) in 30 g L(-1) (TSS30) and 100 g L(-1) TSS (TSS100) suspensions, respectively. Fly ash induced particulate destabilization at rates > or = 50 g L(-1) and reduced solution-phase DRP at all rates > or = 1 g L(-1) by 52 and 71% in TSS30 and TSS100 suspensions, respectively. Aluminum and Fe salts also lowered DRP at rates < or = 10 g L(-1) and higher concentrations redispersed particulates and increased DRP due to increased suspension acidity and electrical conductivity. The DRP release from treated manure solids and a Typic Paleudult amended with treated manure was reduced, although the amendments increased Mehlich 3-extractable P. Therefore, the synergism of flocculant types allowed input reduction in aggregation aid chemicals, enhancing particulate and dissolved P separation and immobilization in high TSS liquid manure.     

Land Cover Changes Between 1968 and 2003 In Cai Nuoc,Ca Mau Peninsula,Vietnam

Since 2000, the shrimp industry expands at a fast rate in the coastal areas of the Mekong Delta, Vietnam. Shrimp farming is known for its negative impact on the coastal environment. However, other human interventions like agriculture and urbanization also deteriorate the coastal environment. The land cover changes between 1968 and 2003 were determined and analyzed for the Cai Nuoc district, Ca Mau Province, Vietnam, using photos from 1968, 1992 (aerial photographs), 1997/98 (Spot) and 2003 (Landsat). It was clear that the district underwent serious land cover changes: deforestation between 1968 and 1992, with a simultaneous increase in rice land; a rapid decline in rice acreage from 1997 onwards, and, simultaneously, a blitz-increase in shrimp farming area. The forest area declined by 75% between 1968 and 2003. About 40% of this loss could be attributed to shrimp farming, while the remaining 60% was attributed to needs for agricultural land. Still, at present, shrimp farming is the major source of mangrove loss in the district. In 1999 shrimp farms covered 6.374 ha, in 2000 they covered 61.049 ha of the Cai Nuoc area. The swap from rice cultivation to shrimp farming was most-probably driven by households’ hopes for a higher income. It must be feared that the shrimp industry will have a negative impact on the environment (e.g. salinization) and on the livelihood of the district’s households. In 1968 saline water covered 219.9 km², in 1992, 1997/98 and 2003 the saline surface water area covered 92.4, 135.2 and 835.0 km², respectively. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

Distribution,seasonal variation and inhalation risks of polychlorinated dibenzo-<Emphasis Type="Italic">p</Emphasis>-dioxins and dibenzofurans,polychlorinated biphenyls and polybrominated diphenyl ethers in the atmosphere of Beijing,China

Spatial distribution, seasonal variation and potential inhalation risks of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were investigated in the atmosphere of Beijing, using passive air samplers equipped with polyurethane foam disks. Concentrations of ΣPCDD/Fs, ΣPCBs and ΣPBDEs ranged from 8.4 to 179 fg WHO₂₀₀₅-TEQ/m³, 38.6–139 and 1.5–176 pg/m³, respectively. PCDFs showed higher air concentrations than those of PCDDs, indicating the influence of industrial activities and other combustion processes. The non-Aroclor congener, PCB-11, was detected in air (12.3–99.4 pg/m³) and dominated the PCB congener profiles (61.7–71.5% to ∑PCBs). The congener patterns of PBDEs showed signatures from both penta-BDE and octa-BDE products. Levels of PCDD/Fs, PCBs and PBDEs at the industrial and residential sites were higher than those at rural site, indicating human activities in urban area as potential sources. Higher air concentrations of PCDD/Fs, PCBs and PBDEs were observed in summer, which could be associated with atmospheric deposition process, re-volatilization from soil surface and volatilization from use of technical products, respectively. Results of inhalation exposure and cancer risk showed that atmospheric PCDD/Fs, dioxin-like PCBs and PBDEs did not cause high risks to the local residents of Beijing. This study provides further aid in evaluating emission sources, influencing factors and potential inhalation risks of the persistent organic pollutants to human health in mega-cities of China.     

Developments in forward osmosis and membrane distillation for desalination of waters

Membrane technology has become a common separation technology over the past decennia. Membranes are used more and more for the production of drinkable water from groundwater, surface water and wastewater. Membranes are now competitive versus conventional techniques. Desalination is predominantly used to eradicate the problem of water scarcity. The sustainability of all desalination processes depends mainly on the reduction of energy costs (production cost) and the increase in water recovery. Forward osmosis and membrane distillation are emerging technologies for sustainable desalination. Here we review membrane processes of forward osmosis and membrane distillation and the advancements in membrane material and modules. We also discuss the capability of membrane distillation in treating highly concentrated aqueous solutions derived from other desalination processes. Furthermore, the advancements in fabrication of high-performance membrane is reviewed and the performance of different membranes and optimization of membrane distillation process are summarized.     

大连市海产品中短链氯化石蜡的含量与分布研究

在大连市金石滩采集海产品,使用GC/ECNI-LRMS技术对样品中短链氯化石蜡(SCCPs)的累积和分布特征进行了研究.结果表明,ΣSCCPs在香螺样品中含量最低,毛蚶样品中含量最高,干重浓度分别为77 ng·g-1和8 250 ng·g-1.ΣSCCPs在鱼类、虾蟹和贝类中的干重浓度分别为100~3 510、394~5 440和77~8 250 ng·g-1.总体上看,海产品中SCCPs碳原子同族体以C10和C11为主,约占总量的61.1%,ΣSCCPs含量越高的海产品倾向于累积更高比重的C12和C13.Cl7、Cl8和Cl6为主要的氯原子同族体,约占总量的87.6%.除了Cl5与Cl10,样品中SCCPs各碳(氯)同族体之间均存在显著相关性,这表明它们可能有着相同的来源和相似的生物蓄积以及迁移转化过程.     

New methods of life expectancy estimation

Environmental and Ecological Statistics - Two novel methods of life expectancy estimation, applied to various annual reported demographic datasets, are proposed. First, for datasets that fully...     

Quantile relationship between globalization,financial development,economic growth,and carbon emissions: evidence from Vietnam

Environmental Science and Pollution Research - Environmental quality and economic activity have a strong relationship. Carbon emissions remain one of the world’s most dangerous environmental...     

Occurrence,toxicity and adsorptive removal of the chloramphenicol antibiotic in water: a review

Chloramphenicol is a broad-spectrum bacterial antibiotic used against conjunctivitis, meningitis, plague, cholera, and typhoid fever. As a consequence, chloramphenicol ends up polluting the aquatic environment, wastewater treatment plants, and hospital wastewaters, thus disrupting ecosystems and inducing microbial resistance. Here, we review the occurrence, toxicity, and removal of chloramphenicol with emphasis on adsorption techniques. We present the adsorption performance of adsorbents such as biochar, activated carbon, porous carbon, metal–organic framework, composites, zeolites, minerals, molecularly imprinted polymers, and multi-walled carbon nanotubes. The effect of dose, pH, temperature, initial concentration, and contact time is discussed. Adsorption is controlled by π–π interactions, donor–acceptor interactions, hydrogen bonding, and electrostatic interactions. We also discuss isotherms, kinetics, thermodynamic data, selection of eluents, desorption efficiency, and regeneration of adsorbents. Porous carbon-based adsorbents exhibit excellent adsorption capacities of 500–1240 mg g^?1. Most adsorbents can be reused over at least four cycles.