附生假单胞菌存在下不同光照时间对铜绿微囊藻生长与磷代谢的影响

通过设置8/16、12/12、16/8不同光暗比,分析了附生细菌存在下不同光照时间对铜绿微囊藻(M icrocystis aeruginosa)生长及其与附生假单胞菌(Pseudom onassp.)磷代谢之间关系的影响。结果表明:光照时间越长,铜绿微囊藻生长越快,16 h光照下的比增长速率为8 h光照下的1.6倍。铜绿微囊藻的快速生长促进了附生细菌中磷的释放;藻细胞增殖越快,附生细菌释放的磷越多。铜绿微囊藻对数生长期末,8、12、16 h光照下附生细菌磷含量分别降至对数生长初期的87.8%、78.6%和64.9%。铜绿微囊藻对附生细菌磷释放的促进作用是由藻细胞生长对磷的消耗再吸收导致的。     

高灵敏XRF测定废水中痕量砷

本文提出了在硫酸介质中,以锌粒还原产生氢化物,溴化铜溶液吸收,微孔滤膜过滤制成薄样,Ｘ射线荧光测定水中痕量砷的分析方法。     

生态文明与农业发展

农业作为国民经济的基础,是生态文明的重要内容,其文明程度直接体现生态文明程度.生态文明建设给农业经营提出了更高的要求,也为农业生产的发展指明了方向.充分认识生态文明建设与农业生产的关系,加强农业相关人员的生态文明教育和农业环保法制建设,实施更加科学、文明的农业经营方式将对促进农业的可持续发展和生态文明建设发挥积极的作用.     

游憩践踏对芜湖赭山城市公园影响研究

城市生态型公园是户外游憩活动影响最集中的一个区域,特别是践踏的影响表现最为明显。对芜湖市赭山生态型城市公园的19条游憩路径进行了调查,路径总长度达3123m。分析了户外游憩活动践踏造成的影响,得出了不同的旅游路径对践踏所引起的路面变宽、植物根系暴露、多路径和路面损伤是不同的,土质路面游道受到践踏影响的程度最大,石板路面游道次之,水泥路面相对最小。城市生态型公园的道路系统建设应该适应游客的游憩需求,减少践踏对公园生态环境的影响,最大化地满足城市居民的需要。     

固相微萃取(SPME)技术在水质监测中的应用

固相微萃取技术(SPME)作为一种样品前处理技术,具有方便、快捷、不使用有机溶剂、灵敏度高、价格低廉等优点,已被广泛地应用于环境样品的分析.本文综合评述了采用SPME法预处理环境水体中的有机物、无机离子等污染物的监测情况,并对SPME法在环境水质监测中的应用以及对国外的研究进展进行了展望.     

旅游购物体验实证研究——以屯溪老街为例

在文献综述的基础上,以屯溪老街为例,运用单因素方差分析方法,从旅游主客体两个方面探讨了旅游者的购物体验及其差异性。在主体方面,旅游者的职业、收入、年龄等社会经济属性和游览时间、购物花费等旅游行为特性变量构成了购物体验的差异性因素;在客体方面,旅游者对于老街的购物环境、商品和服务属性方面的体验差异性显著。最后有针对性地提出了管理措施。     

Adsorption of basic dye from aqueous solution onto fly ash

The fly ash treated by H₂SO₄ was used as a low-cost adsorbent for the removal of a typical dye, methylene blue, from aqueous solution. An increase in the specific surface area and dye-adsorption capacity was observed after the acid treatment. The adsorption isotherm and kinetics of the treated fly ash were studied. The experimental results were fitted using Langmuir and Freundlich isotherms. It shows that the Freundlich isotherm is better in describing the adsorption process. Two kinetic models, pseudo-first order and pseudo-second order, were employed to analyze the kinetic data. It was found that the pseudo-second-order model is the better choice to describe the adsorption behavior. The thermodynamic study reveals that the enthalpy (ΔH⁰) value is positive (5.63 kJ/mol), suggesting an endothermic nature of the adsorption.     

成都雨水处理利用工程措施探讨

成都降水呈现极强的季节性特征,夏季降水占全年降水的50%左右;降雨水质呈现明显偏硝酸的混合酸性.针对成都地区雨水污染物特征,对当前雨水处理及回用工程中的中水工程、屋顶绿化、调蓄池、绿地系统以及湿地系统在成都应用时所应注意的一些关键因素进行了讨论.     

Interaction between BSM-contaminated soils and Italian ryegrass

The interaction among the bensulfuron-methyl, growth of Italian ryegrass, and soil chemical/biochemical/microbiological parameters was investigated in a microcosm experiment. The bensulfuron-methyl added to the soil can be rapidly degraded by certain fungi and actinomycetes present in the original paddy rice soil. The growth of Italian ryegrass significantly accelerated the in-soil degradation of bensulfuron-methyl in its rhizosphere. The uptake of bensulfuron-methyl by ryegrass increased with increasing dosage level of bensulfuron-methyl. However, the phytoextraction of bensulfuron-methyl by ryegrass contributed insignificantly to the total removal of the soil bensulfuron-methyl. Within the dosage range set in this study, the root development of ryegrass was not adversely affected by the presence of the soil bensulfuron-methyl although the fresh biomass of shoot was slightly reduced in the higher dosage treatments. This can be attributed to the adsorption of the added bensulfuron-methyl by soil colloids and consequently the reduction of bensulfuron-methyl level in the soil pore water to a concentration sufficiently lower than the toxic level. The growth of ryegrass significantly increased soil pH and the activities of phosphatase and peroxidase but reduced the EC and the activities of urease in the rhizospheric soil.     

Optimization of photo-Fenton process parameters on carbofuran degradation using central composite design

Carbofuran, one of the most toxic and biorefractory carbamate compounds, is widely used in insecticides in Taiwan (9-18% of total insecticides production per year). In the present study, a central composite design experiment was used to study the effect of photo-Fenton treatment on carbofuran solution and to optimize the process variables such as carbofuran concentration (1-100 mg L(-1)), H(2)O(2) dosage rate (0.25-6 mg L(-1) min(-1)) and Fe(3+) dosage (1-50 mg L(-1)), which influenced the efficiency of carbofuran degradation and mineralization. The results indicated that all the variables investigated in this study had significant roles in the degradation and mineralization of carbofuran in solution. The carbofuran degradation and mineralization efficiencies were increased with increase in H(2)O(2) dosage rate and Fe(3+) dosage, and with decrease in carbofuran concentration. Furthermore, optimum values of both H(2)O(2) dosage rate and Fe(3+) dosage were found to shift to higher values as carbofuran concentration increased. Based on the model obtained in this study, optimum H(2)O(2) dosage rate and Fe(3+) dosage were found to be 4 mg L(-1) min(-1) and 20 mg L(-1), respectively, for 51 mg L(-1) of carbofuran concentration. Under these conditions, carbofuran was completely removed within 30 min and coupled with 78% mineralization at the end of experiment.