餐厨垃圾两相厌氧发酵产甲烷相恶臭排放规律

为了研究餐厨垃圾两相厌氧发酵产甲烷相恶臭排放规律,在中温(35℃)条件下,以餐厨垃圾为发酵底物进行中试规模的两相连续式厌氧发酵试验,并对一个周期内不同时间段产甲烷相产生的气体进行采样,分析其臭气浓度和物质浓度,结合各组分的阈稀释倍数,筛选出主要的恶臭污染物。结果表明,在发酵系统稳定运行阶段,产甲烷相产生的臭气浓度较大,都在23万以上;产甲烷相产生的恶臭物质主要包括硫化物、萜烯类、含氧类和芳烃类四类化合物,其中质量浓度最高的恶臭物质是硫化氢,超过了150 mg/m3;产甲烷相的主要致臭物质是硫化物,其中贡献最大的是硫化氢,其阈稀释倍数都在26万以上,其次为乙硫醇﹥甲硫醇﹥乙硫醚,这3种物质的阈稀释倍数都在4 000以上;除了这4种硫化物,丁醛对恶臭的贡献也比较大,其阈稀释倍数也在4 000以上。     

响应曲面法优化电化学氧化技术处理染料废水

采用IR和XRD等手段对自制磷钼酸铁(FePMo12)杂多酸进行表征,表明杂多阴离子具有Keggin结构。将FePMo12负载于修饰后的分子筛上制备FePMo12/APTES-4A催化剂填充于电化学反应器中,考察电化学氧化体系对酸性大红3R染料废水的脱色效果,其脱色率高于二维电化学反应器。利用Box-Behnken中心组合实验设计及响应面(RSM)分析,以pH值,板间距,槽电压,曝气量为实验因素,建立了以酸性大红3R的脱色率为响应值的二次多项式回归模型。研究表明,当电解时间为60 min时,曝气量0.05 m3/h、pH为2、板间距3.0 cm、槽电压11.0 V,在此条件下色度去除率可达69.4%,模型预测值与实验值能很好地吻合。方差分析结果表明,槽电压和pH、pH和曝气量的交互作用对响应值具有显著性影响。     

添加外源纤维素酶对水稻秸秆模拟堆肥过程的影响

利用水稻秸秆模拟堆肥,对纤维素、半纤维素质量分数及堆肥相关指标随添加外源纤维素酶的变化进行研究。结果表明,与不加酶堆肥相比,添加外源纤维素酶显著提高了水稻秸秆纤维素及半纤维素的降解率,其降解趋势均可用一阶指数衰减方程拟合;堆肥结束时,添加纤维素酶处理的堆肥纤维素质量分数较不加酶处理低35.1%。纤维素酶促进了堆肥中腐殖酸的合成,提高了堆肥中的铵态氮(NO3-N)、硝态氮(NH4-N)及全氮(TN)的质量分数,并导致堆肥中碳素质量分数下降,C/N质量比下降了23.1%;添加纤维素酶进一步降低了堆肥的生物毒性,使得发芽指数提高了10.3%。外源添加纤维素酶加快了水稻秸秆堆肥的腐熟进程。     

基于SLEUTH模型的滇池流域城市扩展模拟分析

通过滇池流域1992～2010年城市扩张研究,发现城市建设用地增长主要表现为两种形态：一是边缘增长,表现为城市建成区范围不断扩大;二是道路影响增长,表现为环滇池道路两边新城市单元的产生。基于滇池流域城市扩展变化遥感数据,对SLEUTH城市扩展模型进行校准,模拟30 a间（2010～2040年）3种预案下的昆明城市扩展变化过程,并对模拟结果进行分析。3种模拟预测结果表明：任意管理预案下城市无序扩张,大量农林用地被城市建设用地占用,人口和城市建设用地呈现爆发式增长,滇池沿岸被城市包围,会对滇池水环境产生极大的压力;土地总量控制预案下城市的发展完全按照城市总体规划内容进行,没有考虑城市实际发展过程中的经济、人口等因素影响,没有达到滇池生态环境保护的需要;生态环境保护预案下,能相对有效控制建设用地,减少对农林用地、湿地的侵占,利于滇池环境保护。预测发现,从滇池流域水资源现状来看,即使实施了环境保护模式,人均水资源量仍处于“严重短缺”状态。需要通过调整昆明城镇体系和产业布局,降低城市首位度和人口;采取更为严格的空间管制策略,有效控制城市空间扩展,以减少对滇池流域的环境压力     

Exploration and exploitation of food sources by social insect colonies: a revision of the scout-recruit concept

Social insect colonies need to explore and exploit multiple food sources simultaneously and efficiently. At the individual level, this colony-level behaviour has been thought to be taken care of by two types of individual: scouts that independently search for food, and recruits that are directed by nest mates to a food source. However, recent analyses show that this strict division of labour between scouts and recruits is untenable. Therefore, a modified concept is presented here that comprises the possible behavioural states of an individual forager (novice forager, scout, recruit, employed forager, unemployed experienced forager, inspector and reactivated forager) and the transitions between them. The available empirical data are reviewed in the light of both the old and the new concept, and probabilities for the different transitions are derived for the case of the honey-bee. The modified concept distinguishes three types of foragers that may be involved in the exploration behaviour of the colony: novice bees that become scouts, unemployed experienced bees that scout, and lost recruits, i.e. bees that discover a food source other than the one to which they were directed to by their nest mates. An advantage of the modified concept is that it allows for a better comparison of studies investigating the different roles performed by social insect foragers during their individual foraging histories. Received: 29 December 1999 / Revised: 25 February 2000 / Accepted: 16 October 2000     

Monitoring of Aerial Pollutants Emitted from Swine Houses in Korea

This on-site survey study was performed to determine the concentrations and emissions of aerial contaminants in the different types of swine houses in Korea and then to present beneficial information available for Korean pig producers to manage optimal air quality in swine house. The swine houses investigated in this research were selected based on three criteria; manure removal system, ventilation mode and growth stage of swine. Mean concentrations of aerial pollutants in swine houses were 8 ppm for ammonia, 300 ppb for hydrogen sulfide, 2 mg m⁻³ for total dust, 0.6 mg m⁻³ for respirable dust, 4 log(cfu m⁻³) for total airborne bacteria and 3 log(cfu m⁻³) for total airborne fungi, respectively. Mean emissions based on pig (liveweight; 75 kg) and area (m²) were 250 and 340 mg h⁻¹ for ammonia, 40 and 50 mg h⁻¹ for hydrogen sulfide, 40 and 50 mg h⁻¹ for total dust, 10 and 15 mg h⁻¹ for respirable dust, 1.0 and 1.3 log(cfu) h⁻¹ for total airborne bacteria and 0.7 and 1.0 log(cfu) h⁻¹ for total airborne fungi, respectively. In general concentrations and emissions of gases were relatively higher in the swine houses managed with deep-pit manure system with slats and mechanical ventilation mode than the different swine housing types whereas those of particulates and bioaerosol were highest in the naturally ventilated swine houses with deep-litter bed system.     

典型环境污染物对肠道菌群的影响及机制研究进展

随着环境污染日益严重,国内外有关环境污染物导致健康风险的毒性机制研究已引起广泛关注.然而,环境污染物对机体肠道菌群结构、功能的改变及其对毒性效应的调控作用研究尚处起步阶段.本综述在归纳近年来国内外人体及模式生物的肠道菌群研究进展的基础上,重点阐述了以重金属污染物、微纳米颗粒污染物、持久性有机污染物以及抗生素为代表的典型...     

量子点对秀丽隐杆线虫的毒性效应及其调控机制的研究进展

量子点(quantum dots,QD)作为一种纳米微晶体,由于其出色的光学特性,已经被广泛应用于电子、生物医学成像、生物传感器和药物递送中,因而量子点的生物安全性也变得至关重要.秀丽隐杆线虫作为一种简单的生物模型,生物学基础完善、生命周期短、繁殖量大、生活特征易获得,不仅可以提供全动物水平的生理相关数据,还允许在单细...     

The monitoring results of electromagnetic radiation of 110-kV high-voltage lines in one urban location in Chongqing P.R. China

To understand electromagnetic radiation field strength and its influencing factors of certain 110-kV high-voltage lines in one urban area of Chongqing by measuring 110-kV high-voltage line’s electromagnetic radiation level. According to the methodology as determined by the National Hygienic Standards, we selected certain adjacent residential buildings, high-voltage lines along a specific street and selected different distances around its vertical projection point as monitoring points. The levels of electromagnetic radiations were measured respectively. In this investigation within the frequency of 5–1,000 Hz both the electric field strength and magnetic field strength of each monitoring sites were lower than the public exposure standards as determined by the International Commission on Non-Ionizing Radiation Protection. However, the electrical field strength on the roof adjacent to the high-voltage lines was significantly higher than that as measured on the other floors in the same buildings (p < 0.05). The electromagnetic radiation measurements of different monitoring points, under the same high-voltage lines, showed the location which is nearer the high-voltage line maintain a consistently higher level of radiation than the more distant locations (p < 0.05). Electromagnetic radiation generated by high-voltage lines decreases proportionally to the distance from the lines. The buildings can to some extent shield (or absorb) the electric fields generated by high-voltage lines nearby. The electromagnetic radiation intensity near high-voltage lines may be mitigated or intensified by the manner in which the high-voltage lines are set up, and it merits attention for the potential impact on human health.     

A Complementarity Approach for an Environmental–Economic Game with Coupling Emission Constraints

We consider an environmental–economic game where players face not only Cournot competition but also coupling environmental and individual capacity constraints. Under the complementarity problem framework, we study the existence of the (normalized) Nash equilibrium, computability of the equilibria, and the closed form expressions of the optimal weights. We also report numerical results of two examples as well as the insights gained from them.