IFRP: a hybrid interval-parameter fuzzy robust programming approach for waste management planning under uncertainty

In this study, an interval-parameter fuzzy-robust programming (IFRP) model is developed and applied to the planning of solid waste management systems under uncertainty. As an extension of the existing fuzzy-robust programming and interval-parameter linear programming methods, the IFRP can explicitly address system uncertainties with complex presentations. Parameters in the IFRP model can be represented as interval numbers and/or fuzzy membership functions, such that the uncertainties can be directly communicated into the optimization process and resulting solution. Furthermore, highly uncertain information for the lower and upper bounds of interval parameters that exist due to the complexity of the real world can be effectively handled through introducing the concept of fuzzy boundary interval. Consequently, robustness of the optimization process and solution can be enhanced. Results of the case study indicate that useful solutions for planning municipal solid waste management practices can be generated. They reflect a compromise between optimality and stability of the study system. Willingness to pay higher costs will guarantee the system stability; however, a desire to reduce the costs will run the risk of potential instability of the system. The results also suggest that the proposed hybrid methodology is applicable to practical problems that are associated with highly complex and uncertain information.     

有机污染土壤通风去污技术研究进展

土壤气体抽排净化技术是一种安全、高效、经济的有机污染土壤治理技术。本文系统分析了土壤气体抽排净化技术的特点、现状及发展趋势 ;总结了估算污染物净化时间的数学模型 ;概括了影响土壤气体抽排净化技术净化时间的主要因素 ,包括土壤透气率、含水率、有机污染物气体饱和蒸气压、抽排流速、环境温度 ;本文还对目前土壤气体抽排净化技术需要研究的问题及发展前景进行了展望。     

Characteristics and impacts of trace elements in atmospheric deposition at a high-elevation site,southern China

To investigate the regional background trace element (TE) level in atmospheric deposition (dry and wet), TEs (Fe, Al, V, Cr, Mn, Ni, Cu, Zn, As, Se, Mo, Cd, Ba, and Pb) in 52 rainwater samples and 73 total suspended particles (TSP) samples collected in Mt. Lushan, Southern China, were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS). The results showed that TEs in wet and dry deposition of the target area were significantly elevated compared within and outside China and the volume weight mean pH of rainwater was 4.43. The relative contributions of wet and dry depositions of TEs vary significantly among elements. The wet deposition fluxes of V, As, Cr, Se, Zn, and Cd exceeded considerably their dry deposition fluxes while dry deposition dominated the removal of pollution elements such as Mo, Cu, Ni, Mn, and Al. The summed dry deposition flux was four times higher than the summed wet deposition flux. Prediction results based on a simple accumulation model found that the content of seven toxic elements (Cr, Ni, Cu, Zn, As, Cd, and Pb) in soils could increase rapidly due to the impact of annual atmospheric deposition, and the increasing amounts of them reached 0.063, 0.012, 0.026, 0.459, 0.076, 0.004, and 0.145 mg kg^?1, respectively. In addition, the annual increasing rates ranged from 0.05% (Cr and Ni) to 2.08% (Cd). It was also predicted that atmospheric deposition induced the accumulation of Cr and Cd in surface soils. Cd was the critical element with the greatest potential ecological risk among all the elements in atmospheric deposition.     

“老龄期”填埋场渗滤液COD蒸发规律研究

“老龄期”填埋场渗滤液由于可生化性差而难于处理。采用常规蒸发、减压蒸发和载气蒸发处理不同pH值的“老龄期”渗滤液。实验结果表明，3种蒸发方式下，冷凝液CODF降过程中均存在明显的浓度转折点，转折点之后COD维持较低水平，为“老龄期”渗滤液的“三分处理法”提供理论依据。与常规蒸发相比，减压蒸发和载气蒸发的前期冷凝液COD较高，且浓度转折点偏后。     

Prediction and cause investigation of ozone based on a double-stage attention mechanism recurrent neural network

● Used a double-stage attention mechanism model to predict ozone. ● The model can autonomously select the appropriate time series for forecasting. ● The model outperforms other machine learning models and WRF-CMAQ. ● We used the model to analyze the driving factors of VOCs that cause ozone pollution. Ozone is becoming a significant air pollutant in some regions, and VOCs are essential for ozone prediction as necessary ozone precursors. In this study, we proposed a recurrent neural network based on a double-stage attention mechanism model to predict ozone, selected an appropriate time series for prediction through the input attention and temporal attention mechanisms, and analyzed the cause of ozone generation according to the contribution of feature parameters. The experimental data show that our model had an RMSE of 7.71 μg/m³ and a mean absolute error of 5.97 μg/m³ for 1-h predictions. The DA-RNN model predicted ozone closer to observations than the other models. Based on the importance of the characteristics, we found that the ozone pollution in the Jinshan Industrial Zone mainly comes from the emissions of petrochemical enterprises, and the good generalization performance of the model is proved through testing multiple stations. Our experimental results demonstrate the validity and promising application of the DA-RNN model in predicting atmospheric pollutants and investigating their causes.     

Residues of fluoroquinolones in marine aquaculture environment of the Pearl River Delta, South China

Concentrations and distributions of selected fluoroquinolones (norfloxacin, ciprofloxacin and enrofloxacin) in water, sediments and nine kinds of fish species collected from 6 sites in two marine aquaculture regions of the Pearl River Delta, China, were analyzed by using high-performance liquid chromatography with fluorescence detector (HPLC). The results showed that the concentrations of ciprofloxacin and enrofloxacin were below the limits of quantification (LOQ) in all water samples except for norfloxacin. Norfloxacin and ciprofloxacin concentrations ranged from 1.88 to 11.20 ng g⁻¹ dry wt, 0.76–2.42 ng g⁻¹ dry wt in sediments collected from the Dapeng’ao region (sites 1–3) and ranged from 2.31 to 4.75 ng g⁻¹ dry wt, 1.26–1.76 ng g⁻¹ dry wt in sediments collected from the Hailing Island region (sites 4–6), respectively. However, no enrofloxacin was found in all sediment samples. The three fluoroquinolones (FQs) were detected in all fish samples, and the concentrations were higher in liver tissues than those in muscle tissues. The levels of norfloxacin were higher than ciprofloxacin and enrofloxacin in both liver and muscle tissues. Among the nine marine fish species, Siganus fuscescens from Hailing Island had a significantly high level of norfloxacin in liver tissue (254.58 ng g⁻¹ wet wt), followed by Sparus macrocephalus (133.15 ng g⁻¹ wet wt) from Dapeng’ao, and the lowest value was Lutianus argentimaculatus (5.18 ng g⁻¹ wet wt) from Hailing Island. The obtained results of FQs in present study do not represent a risk to the human health in Guangdong coastal area, based on the maximum residue limits (MRLs) established by Chinese Government and the acceptable daily intake (ADI) recommended by the Food and Agriculture Organization and World Health Organization (FAO/WHO).     

Reproductive competition and fecal testosterone in wild male giant pandas (<Emphasis Type="Italic">Ailuropoda melanoleuca</Emphasis>)

The giant panda (Ailuropoda melanoleuca) is notoriously difficult to study in the wild, but its interesting reproductive ecology makes the effort worthwhile. Perhaps more than most species, the panda is energy-limited, which alters the cost/benefit analysis of its reproductive ecology. Using global positioning system/very high frequency radiocollars to locate mating aggregations, we used behavioral observations and fecal testosterone assays to gain insight into male panda reproductive effort and strategies, and test theories relating to reproductive competition. Male pandas initially competed fiercely for access to females that were about to be fertile, but once male competitive status was determined, aggression rates declined. Contact aggression was only observed during the first 2 days of mating aggregations; thereafter, it was replaced with noncontact aggression and avoidance. Agonistic interactions were highly asymmetrical, with contest losers (subordinates) showing less aggression and more avoidance than contest winners (dominants), both before and after contest outcome was established. The competitively superior male displayed mate-guarding tactics and secured all observed copulations. Contrary to theoretical predictions, testosterone levels did not predict aggression levels or contest winners and also were not affected by winning or losing a contest. Body size appeared to be the primary determinant of contest outcome. We discuss our findings in light of theoretical predictions, such as those arising from the “challenge hypothesis,” in the context of the giant panda’s foraging and nutritional ecology.     

Decomposition of simulated odors in municipal wastewater treatment plants by a wire-plate pulse corona reactor

Decomposition of simulated odors in municipal wastewater treatment plants was investigated experimentally by a wire-plate pulse corona reactor. A new type of high pulse voltage source with a thyratron switch and a Blumlein pulse forming network (BPFN) was adopted in our experiments, and the testing malodorants were ammonia, ethanethiol and tri-methyl amine, respectively. The maximum output power of the pulse voltage source and the maximum peak voltage were 1 kW and 100 kV. The experiments were conducted at the gas-flow rate of 4.0-23.0 m3 h(-1). Important parameters, including peak voltage, pulse frequency, capacitance (inductance) of the BPFN, gas-flow rate, initial concentration, which influenced on the removal efficiency, were investigated. The results show that the odors can be treated effectively. Almost 100% removal efficiency was obtained for 32 mg m(-3) ammonia at the gas-flow rate of 4.0 m(3) h(-1). The maximum removal efficiencies of 85 mg m(-3) ethanethiol and 750 mg m(-3) tri-methyl amine at 10.0 m(3) h(-1) were 98% and 91%, respectively. The energy yield of 110 mg m(-3) ammonia was 2.99 g kWh(-1) when specific energy density was 106 Jl(-1). In the cases of ammonia, ethanethiol and tri-methyl amine removal, ozone and nitrogen oxides were observed in the exit gas. The carbon and sulfur elements of ethanethiol and tri-methyl amine were mainly converted to carbon dioxide, carbon monoxide and sulfur dioxide. Moreover, the ammonium nitrates and sulfur were discovered in the reactor.     

我国危险废物管理现状及发展趋势

本文介绍了我国危险废物产生量、分布特点、管理现状及发展趋势 ,分析了我国地方及云南省危险废物管理中存在的问题 ,提出了解决问题的对策和建议。