Development of an Expert System for the Remediation of Petroleum-Contaminated Sites

Groundwater and soil contamination caused by light nonaqueous phase liquids (LNAPLs) spills and leakage in petroleum industry is currently one of the major environmental concerns in North America. Numerous site remediation technologies, generally classified as ex situ and in situ remediation techniques, have been developed and implemented to clean up the contaminated sites in the last two decades. One of the problems associated with ex situ remediation is the cost of operation. In recent years, in situ techniques have acquired popularity. However, the selection process of the desired techniques needs a large amount of knowledge. Insufficient expertise in the process may result in unnecessary inflation of expenses. In this study, petroleum waste management experts and Artificial Intelligence (AI) researchers worked together to develop an expert system (ES) for the management of petroleum contaminated sites. Various AI techniques were used to construct a useful tool for site remediation decision-making. This paper presents the knowledge engineering processes of knowledge acquisition, conceptual design, and system implementation in the project. The expert system was applied to a real-world case study and the results show that the expert system can generate desired remediation alternatives to assist decision-makers. The application case study constitutes partial validation of the prototype expert system.     

Efficiency of Modified H2S Test for Detection of Faecal Contamination in Water

Faecal contamination is a major causative factor for incidence of water borne infectious diseases. Certain hydrogen sulfide (H₂S) producing enteric bacteria such as Salmonella sp. and Citrobacter sp., assosiated with coliforms, have been considered for rapid detection of recent faecal contamination in water. The basic H₂S test medium, modified by adding 0.25 gm/L of L-cystine HCl, was examined for its efficiency with 90 water samples collected from 40 pipe supplies, 20 open wells, 15 hand pumps and 15 different surface water bodies (river, streams and ponds). Sterilized modified culture medium in glass vials was inoculated with 100 mL of each sample and incubated at 20, 25, 30, 35 and 44 ^∘C for 18, 24, 42, 48, 66 and 72 h. Blackening of content in incubated vials was considered positive. For comparison, most probable number (MPN) of coliform and faecal coliform per 100 mL was also estimated in each sample by multiple tube fermentation (MTF) method. H₂S positive result was exhibited by 78% of samples. Coliform (> 10) and faecal coliform/100 mL were also detected in 59% of samples. Maximum H₂S positive results (100%) were found with well and surface water samples incubated at 30, 35 and 44 ^∘C for 18 h. Coliform (> 10) and faecal coliform/100 mL were also detected in most of these samples. Pipe supplies (60%) and hand pumps (73%) also exhibited considerable H₂S production. Coliforms and faecal coliforms were also found in significant number of these samples. Thus, the modified H₂S test may prove a useful alternative indicator of faecal contamination for water quality surveillance and screening of large number of water samples in short duration, particularly during any outbreak of water borne disease among rural population.     

中国中部农区乡村重构特征及其地域模式——以江汉平原为例

以人地关系理论为基础,以乡村地域系统内部要素变化解析乡村重构特征、外部环境变化解读乡村重构机理、外源驱动因素与内生响应要素耦合解译乡村重构模式。基于江汉平原的实证研究表明：（1）研究期内乡村地域持续经历重构过程,表现为乡村重构综合指数不断增加,高值区主要沿域内交通干线分布、低值区主要分布长江沿线和平原腹地;（2）乡村重构机制主要表现为工业化、城镇化、市场化等外源驱动因素与经济、社会、空间等内生要素的耦合作用,非农产业规模扩张引发乡村人口外迁和就业转移,进而推动人口、土地和产业等乡村“存量”要素重组;（3）经济—社会重构主导是江汉平原乡村重构的主流模式,产业结构和生产方式变化加剧乡村生态环境和人居环境恶化,乡村振兴及其可持续发展面临水环境污染和水灾害侵袭的双重挑战。研究框架能够揭示江汉平原乡村地理剧变特征,中国中部农产品主产区的乡村重构具有与发达地区不尽相同的图景。研究结果意在为乡村地理研究和乡村振兴实践提供有益启示。     

地下水污染修复技术验证评价方法研究

随着工业生产的飞速发展,我国地下水污染问题日益突出,亟需大量高效的修复技术以提高对地下水污染的治理效果.然而,现有的专家评估体系难以客观、科学地反映技术的真实性能,也很难促进其推广应用,因此亟需加快ETV（environmental technology verification,环境技术验证评价）研究,创建客观、公正和科学的地下水污染修复技术验证评价体系.基于此,采用层次分析法建立了由目标污染物去除效果、副产物情况、固体废物、废水、废气、噪音、自动化水平、故障情况、适用场地类型、基建费用、药剂投加量、能源消耗和资源回收利用共13个指标组成的地下水污染修复技术验证评价指标体系.依据相关技术规范和专家咨询意见,制定了指标评价标准和方法;基于聚类分析方法,以25个地下水污染修复技术为研究对象,对分类评价和综合评价进行评价结果分级.按照由优到差的级别,分类评价结果分为优秀、合格、不合格3个等级,综合评价结果分为优秀、良好、合格、基本合格和不合格5个等级,由此构成了地下水污染修复技术验证评价方法.为了验证该评价方法的科学性和可行性,利用该方法对某项地下水污染修复技术进行了案例分析.研究显示,所构建的地下水污染修复技术验证评价方法可客观有效地评价地下水修复技术的先进性和适用性,并能够提供改进技术性能的进一步建议.      

污染地下水零价铁原位反应带修复技术:理论·应用·展望

ZVI-IRZ(零价铁原位反应带)是一种新兴的地下水原位修复技术,具有工程造价低、施工简单、环境扰动小、修复效果好等优势, 而ZVI(零价铁)自身理化性质、场地的水文地球化学特征以及场地的污染状况等是影响修复效果的主要因素. 当前的研究内容主要包括IRZ(原位反应带)中ZVI的反应活性、稳定性、迁移性、生物毒性以及注入方式等方面. 在修复工程中存在的问题主要体现在:①ZVIs(细粒径零价铁)在含水介质中的迁移性较差,并且多采用Fe2+、pH等间接指标考察含水层中ZVIs的分布情况;②ZVIs表面钝化而诱发介质反应活性下降;③ZVIs的潜在生物环境效应尚不明确. 因此,需要加强对ZVIs表面改性手段、作用机制、老化特性、使用寿命、解钝化及钝化抑制技术等方面的理论与应用研究,还应关注ZVIs在环境中的归趋、转化机制和暴露路径,建立生态系统尺度上的评估体系; 同时,在实际应用中,需要在系统评估污染场地水文地质条件的基础上,加强对注入含水层中ZVIs及其反应产物的原位监测技术研发和监测体系完善.      

重金属复合污染下草本植物两两组合水培的富集特性

为了探明草本植物两两组合培养对其重金属富集特性的影响,寻求修复V、Pb、Cd、Cr复合污染的最佳草本植物组合模式,在V、Pb、Cd、Cr 4种重金属〔ρ分别为14.0、0.8、6.0、4.0 mg/L〕共存的水培条件下,研究蒌蒿(Artemisia selengensis turcz)、三叶草(Trifolium repens)、鱼腥草(Houttuynia cordata)和紫花苜蓿(Medicago sativa) 4种草本植物两两组合培养时的重金属富集特性,以及对植物生物量、重金属富集量和转运系数的影响. 结果表明:4种草本植物两两组合培养会在不同程度上影响植物的重金属富集特性,在重金属富集能力方面,蒌蒿、鱼腥草和紫花苜蓿分别与三叶草组合培养时,其地上部分w(Cr)分别比单独培养时提高约157%、303%、639%;两两组合培养时,紫花苜蓿可促进蒌蒿、鱼腥草和三叶草对Pb的吸收. 在重金属转移能力方面,效果最突出的是“三叶草‖紫花苜蓿”组合模式,其中三叶草对V、Pb、Cd、Cr 4种重金属的转运系数分别是单独培养时的1.19、2.52、22.60和1.67倍;对不同组合模式下植物地上部分重金属提取量的分析结果显示,“三叶草‖紫花苜蓿”组合模式对V、Pb、Cd、Cr 4种重金属的提取量均较高,分别为1 555、1 688、473、482 mg/kg,表明该组合模式能够有效缓解地表径流对附近土壤造成的叠加污染. 因此,水培条件下不同草本植物两两组合培养会改变植物的重金属富集特性,并且与植物种类有关.      

石油污染土壤的原位生物修复技术和多种土壤改良剂应用研究

土壤中的石油污染是一类严重的环境危害.针对石油污染的土壤修复技术有物理法、化学法和生物法.其中原位生物修复法由于简易性和生态可持续等优点成为了具有前景的一个发展方向.土壤改良剂的选取和添加是原位生物修复法中重要的一个部分,对生物修复的改进起到了至关重要的作用.土壤改良剂的种类有无机改良剂、有机改良剂和吸附性改良剂.以N、P、K为主的无机改良剂主要为生物生长提供营养元素;有机改良剂则可提高石油污染物流动性,提供生物碳源;吸附改良剂则通过吸附污染物,减少毒性,提供生物生长依附.通过对不同种类改良剂的分析和讨论,可为生物修复发展提供进一步的理论基础.     

秦皇岛港东港区煤尘污染与气象特征关系分析

本文分析了秦皇岛港东港区煤尘污染与气象条件的关系,分析结果表明,表征煤尘污染的因子总悬浮颗粒物及降尘与自然降水、大风等气象因子具有明显的相关性,并依据分析提出了相应的管理建议。     

Contamination, Crop Trials, and Compatibility

This paper examines the ethical andsocial questions that underlie the present UKdiscussion whether GM crops and organicagriculture can co-exist within a given regionor are mutually exclusive. A EuropeanCommission report predicted practicaldifficulties in achieving sufficientseparation distances to guarantee lowerthreshold levels proposed for GM material inorganic produce. Evidence of gene flow betweensome crops and their wild relatives has beena key issue in the recent Government consultation toconsult on whether or not to authorizecommercial planting of GM crops, following theresults of the current UK farm scale trials.The admixture of imported Bt transgenes intolandrace varieties of Mexican maize alsopresents difficulties. An ethical evaluationis made of the claim that organic growersshould expect protection from adventitioustraces of GM constructs in their products. Towhat extent – on either side of the debate –can any particular group in society set upagricultural standards for itself that mayeffectively restrain others from an otherwisejust business? The assumptions behind notionslike ``purity'' and ``contamination'' areexamined, together with their underlying viewsof nature and human intervention. The 2001UK Agriculture and Environmental BiotechnologyCommission report is relevant to theseissues. While the Government wishes to promotethe UK biotechnology industry and is underpressure from US claims of trade restraint, astrong organic lobby demands purity from GMcontamination. Does this adversarial framingof the issues reflect broader public opinionin the UK public consultation? Inarriving at policy decisions, the role of thevirtue of tolerance is considered inpost-modern and Christian ethical contexts.     

黄河三角洲原油污染土壤的微生物固定化修复技术

研究从原油污染土壤中驯化分离出高效石油烃降解菌系,以海藻酸钠和硅藻土复合载体将其制备成固定化菌,比较了固定化降解菌与游离菌对土壤中原油的降解率以及它们在土壤中活性与数量的变化.结果表明,土著降解菌经驯化后显示了较高的耐受性和环境适应能力,固定化降解菌产生了较同等菌量的游离菌明显高的降解优势,特别是在实验初期(20天时)...