Biological Control of Water Hyacinth Under Conditions of Maintenance Management: Can Herbicides and Insects Be Integrated?

Neochetina eichhorniae and N. bruchi. We therefore sampled water hyacinth and weevil populations at 54 sites distributed statewide. Half were under maintenance control, half were not treated with herbicides. General site conditions were assessed, demographic data were collected on weevil and plant populations, the reproductive condition of the weevils was determined, and plant nutrient and proximate composition of water hyacinth leaves were analyzed. Water hyacinth infestations under maintenance control were minimal when compared to unmanaged sites. Likewise, on a population basis, all weevil cohorts were much lower due to the paucity of plants. Plants at unmanaged sites, where weevil intensities were much higher, suffered high levels of stress and showed low growth potential. Lower percentages of the female weevils were reproductive at unmanaged sites when compared to managed sites, so densities of reproductives and immatures were similar at both site types. Reproductive status of the weevils improved with increased plant quality. Plant quality, in turn, declined as stresses arising from weevil feeding increased. Plant quality was positively correlated with plant growth potential and flower production. Thus, maintenance control improved plant nutritive quality thereby inducing reproductive vigor of the weevils, but ensuring plant regrowth and the need for future control. This suggests that biological and herbicidal controls should be integrated, using herbicides to maintain water hyacinth infestations below management thresholds but in a manner that conserves biological control agent populations. This approach would lead to improved plant nutritional quality that would, in turn, stimulate reproduction in biological control agent populations.     

碧流河水库水质状况的模糊模式识别及对策讨论

提出了确定污染指标权重的新方法,运用陈守煜建立的模糊模式识别理论模型对大连市碧流河水库连续３ａ的水质进行了综合评价,并探讨了水质保护对策      

推广固硫型煤改善城市空气环境质量

本文论述了固硫型煤在燃煤锅炉尤其是小型茶炉,洗浴炉及采暖炉上具有能消烟,除尘,脱硫 性。目前推广固型改善城市空气环境质量是经济,简便,易于,有效的实用措施。     

废水处理中pH值计算机模糊控制系统的设计

酸碱中和是化工废水处理中的一个重要环节。本ｐＨ值控制系统采用ＰＩＤ控制和模糊控制并列转换形式,当系统的偏差较小时,采用ＰＩＤ法进行流程控制;而当系统的偏差较大时,采用计算机模糊控制。介绍ｐＨ值计算机模糊控制系统设计原理与模糊控制器的实现,包括模糊化处理、模糊规则库的建立、模糊计算和反模糊化处理。在废水处理工艺流程中采用该控制方法可获得高效、稳定的控制效果。     

珠海市坡地开垦引发的水土流失及其防治措施

珠海市被地开垦侵蚀的面积为756．82hm2,主要分布于西区斗门县的乾务、五山、斗门等镇,以及平沙区、三灶区等地海拔10～50m、坡度大于10的丘陵台地;侵蚀强度以中度侵蚀为主．平均侵蚀模数2380t／（km2·a）。造成坡地开垦侵蚀的主要原因是开垦利用过程中水土保持措施没有跟上,选择的坡地坡度过大,本文针对珠海市坡地开垦侵蚀的特点,建议采用等高绿篱耕作、山边沟技术、复合农村技术等几项坡地水土保持措施。     

南京市小型餐饮娱乐服务业废水排放系数计算

运用数理统计学的分层抽样法对南京市2001年-2003年小型餐饮娱乐服务业废水中具有相关性的主要污染因子的排放浓度进行了统计,并计算出排放系数,提出用计算的废水排放系数征收小型餐饮娱乐服务业的排污费,实例表明,在该行业运用这一方法征收排污费是可行的。     

化学法处理高浓度电镀废水

分析、总结了采用化学法处理高浓度电镀废水中的含氰废水、含镍废水、含铬废水和含酸废水的工程设计、调试和实际运行情况。实践表明,化学法处理高浓度电镀废水是行之有效的,而用PH／ORP计控制好废水处理中的化学反应是稳定运行的关键。     

污染控制中混合菌的研究

论述优势混合菌的选育混合菌在废水污染物的降解及废物资源化中的作用,指出目前存在的问题和今后的发展方向。     

环境治理中光催化剂的失活与再生

催化剂失活是影响光催化过程用于污染治理经济实用的关键因素。对近几年来国内外环境污染控制中光催化剂的失活现象及其原因进行了综述．分析了液相和气相光催化反应体系中催化剂失活后再生的方法．特别是对气相光催化反应中水蒸汽的影响进行了讨论。     

污水处理系统臭气污染问题的研究

通过对污水处理系统中臭气来源和特征的分析 ,系统地阐述臭气产生的原因和测定、处理方法 ,指出对臭气控制是今后污水处理系统发展的方向之一。