黄土性土壤对垃圾渗滤液的净化作用

【目的】研究黄土性土壤对垃圾渗滤液的净化作用,为黄土地区垃圾填埋场渗滤液的污染控制,以及填埋场覆盖层的选材及厚度设计等提供参考依据。【方法】分别采集耕层(0～25cm)、犁底层(25～60cm)、黏化层(60～120cm)和钙积层(120～175cm)土壤,按不同液土比(体积(mL)质量(g)比,下同;5∶1,10∶1,20∶1,30∶1)加入垃圾渗滤液,采用静态和动态吸附试验,研究不同土层土壤对垃圾渗滤液中COD、NH4+-N的吸附特征及COD去除率随时间的变化规律。【结果】耕层、黏化层、钙积层土壤在振荡4h、犁底层土壤在振荡2h时,对垃圾渗滤液中COD的吸附量达到最大;犁底层、黏化层、钙积层土壤在振荡2h、耕层土壤在振荡1h时,对垃圾渗滤液中NH4+-N的吸附量达到最大;随着液土比的增大,不同土层(除犁底层外)土壤对渗滤液COD、NH4+-N的吸附量逐渐增加。【结论】黄土性土壤对垃圾渗滤液中的COD吸附净化可分为全吸附阶段、部分吸附阶段和基本饱和阶段。综合分析不同土层对垃圾渗滤液中COD、NH4+-N的吸附净化作用,填埋场覆盖层应选择耕层及黏化层土壤,覆盖层厚度以100cm为宜。     

PRB修复垃圾渗滤液污染地下水过程中pH值变化分析

随着城市化的不断发展,生活垃圾产生量越来越多,因管理不善,导致垃圾渗滤液污染地下水的问题越来越突出,污染地下水的修复研究迫在眉睫。实验模拟地下环境,以被垃圾渗滤液污染地下水为研究对象,分别用沸石、无烟煤、陶粒、活性炭、炉渣、粉煤灰、零价铁作为反应介质,设计了6种地下可渗透反应墙（PRB）,分别为反应器1、2、3、4、5和6。分3个阶段对PRB技术治理污染地下水中pH值影响和变化进行模拟研究,分析反应器pH值降低的原因并探讨pH值变化机理。实验结果表明,所有反应器pH值较进口降低,第三阶段出口pH值平均值较进口平均降低0.40;因水解酸化反应存在,产生一定量NH4＋和有机酸,造成反应器出水pH值降低和复合填充材料NH4＋相对去除率降低,说明PRB技术治理渗滤液污染地下水具有一定可行性,但技术方法有待继续深入研究。     

中国洞庭湖区稻田土壤氮素淋溶损失的系统研究

A two-year lysimeter study was conducted to study the effects of different fertilizers and soils on nitrogen leaching loss in a double rice cropping system by considering three major types of paddy soils from the Dongting Lake area. The results showed that N concentration in the leachate did not differ significantly among the treatments of urea, controlled release N fertilizer and pig manure and that all these fertilizers produced higher total nitrogen (TN) concentrations in the leachate compared to the case where no fertilizer was applied. The TN leaching loss following urea treatment accounted for 2.28%, 0.66%, and 1.50% of the amount of N applied in the alluvial sandy loamy paddy soil (ASL), purple calcareous clayey paddy soil (PCC), and reddish-yellow loamy paddy soil (RYL), respectively. Higher TN loss was found to be correlated with the increased leachate volume in ASL compared with RYL, and the lowest TN loss was observed in the PCC, in which the lowest leachate volume and TN concentration were observed. Organic N and NH4+ -N were the major forms of N depleted through leachate, accounting for 56.8% and 39.7% of TN losses, respectively. Accordingly, soil-specific fertilization regimens are recommended; in particular, the maximum amount of fertilizer should be optimized for sandy soils with a high infiltration rate. To avoid a high N leaching loss from rice fields, organic N fertilizers such as urea or coated urea should primarily be used for surface topdressing or shallow-layer application and not for deep-layer application.     

二氧化氯在低浓度垃圾渗滤液深度处理中的应用研究

利用二氧化氯的强氧化性,对经生物处理后的垃圾渗滤液出水进行深度处理,当处理的进水CODCr浓度小于300 mg.L-1时,控制流量为100 L.h-1,投加适当浓度二氧化氯进行深度处理后,可使出水pH接近中性,出水水质达到垃圾渗滤液国家一级排放标准,同时,该处理技术对污水中的微生物具有很好的杀灭效果。大量实验研究表明,采用二氧化氯对低浓度垃圾渗滤液进行深度处理在工艺技术上是可行的,但当渗滤液有机污染浓度较高时,采用二氧化氯进行深度处理,并不是最佳选择。     

Water immersion time reduces the preference of juvenile tropical spiny lobster Panulirus ornatus for pelleted dry feeds and fresh mussel

Development of a pelleted dry feed as an alternative to feeding fresh fishery by‐catch is an environmental priority for tropical spiny lobster aquaculture. Earlier studies have shown the lobster's acceptance of pelleted dry feed diminishes rapidly after immersion in water. In this work, we quantified the rate at which dry matter, total protein, soluble protein and individual and total free amino acids were lost from pieces of green‐lipped mussel Perna canaliculus, a commercially‐extruded Penaeus japonicus (kuruma) shrimp feed (KSF) and four laboratory‐made, fishmeal‐based, pelleted feeds upon immersion for up to 7.5 h. The laboratory‐made feeds contained homogenates of either green‐lipped mussel, polychaete (Marphysa sanguinea), prawn (Metapenaeus bennettae) or squid (Sepioteuthis spp.). After being immersed in water for 0, 2.5 or 5 h, these same feeds were offered as a paired choice with KSF in two preference feeding studies with juvenile Panulirus ornatus lobsters. The loobster's preference for fresh mussel always exceeded that of KSF, irrespective of immersion time. Regression of the proportional intake of test feeds against the relative leach rate of KSF identified soluble protein, glycine and taurine as the principal leachate components having the highest positive correlations with the lobster's feeding preference.     

膜覆盖好氧堆肥的冷凝液和渗滤液二次污染防治设计

为提高膜覆盖好氧堆肥系统在南方潮湿多雨地区推广的适用性,解决冷凝液、渗滤液污染,本文对不同批次牛粪-秸秆混合物膜覆盖好氧堆肥的冷凝液进行了检测,对常规膜覆盖好氧堆肥发酵槽进行了二次污染防治优化设计。分析了常见做法的优缺点,设计了U型导流护套、组合式HDPE膜防渗底板、雨污分流系统,优化了并列槽渗滤液导排系统,提出了系统运行期间污染防治措施建议。结果表明,牛粪-秸秆混合物膜覆盖好氧堆肥冷凝液的PH为8.6~9.2,氨氮含量为17.9~196 mg·L-1、COD为102~230mg·L-1,硫化物含量为0.046~0.178 mg·L-1,PH、氨氮、COD指标超过了污水综合排放标准限值,不能直接排放。优化设计后的系统经工程实施检验可基本杜绝系统露天运行时的冷凝液、渗滤液的二次污染问题。但当堆肥处理量大、系统使用频繁时,建议设置遮雨棚以提高效率,降低劳动强度。     

风干污泥修复后淋洗液对黑麦草初期生长与重金属富集的影响

采用不同浓度DTPA强化修复风干污泥中的重金属,之后对基质进行淋洗,以获得的淋洗液培植黑麦草,研究了淋洗液对黑麦草初期生长及重金属富集的影响。结果表明,淋洗液中含有丰富的无机矿质元素,能够满足植物的生长需要。与对照相比,修复过程中20 mmol.kg-1DTPA未种植物处理的淋洗液显著抑制黑麦草的萌发,推迟黑麦草萌发的高峰期,且降低了黑麦草的地上生物量,其余处理的萌发数与对照差异不显著。各处理淋洗液培养的黑麦草在叶绿素含量上较对照有不同程度的增加,其中10 mmol.kg-1DTPA+隔层处理的淋洗液较对照提高了91.2%。在对重金属的富集中,各处理淋洗液培植的黑麦草地上部和根部的Cd、Cr、Cu、Zn和Pb的浓度显著提高,尤其20 mmol.kg-1DTPA未种植物处理要显著高于对照和其他淋洗液处理。对于同一金属而言,同一处理下根部浓度要远远高于地上部。相同处理下,黑麦草地上部对不同重金属富集系数表现为Zn最大,Pb最小,根部则表现为Cd、Pb较大,Zn较小,且Zn从地下向地上的转运能力最强。和其他4种重金属相比,黑麦草对Zn具有较强的吸收潜力,可作为Zn污染土壤植物修复的备选植物。     

Screening and Application of Functional Bacteria in the Advanced Treatment Process of Landfill Leachate

To improve organic pollutant degradability of landfill leachate, culture medium was prepared with landfill leachate and agar.And then three functional bacteria were cultured and screened from sludge in aeration pool of biochemical treatment system by bioaugmentation.Based on 16S rDNA identification, these bacteria were named Mari nobacter (coded Y1), Acinetobacter (coded Y2) and Escherichia (coded Y3).Functional bacteria were scaling up, and then inoculated into biological activated carbon (BAC) reactor by physical circle absorption method.With the control experiment, it was shown that the natural start up BAC had significant degradation capacity to organic pollutants with molecular weight M of 10 ~ 5 kDa.And the inoculums' start up BAC with functional bacteria was kept with was with removal rate of 76.1% for organic pollutants with molecular weight M of 100 ~ 30 kDa, and 80.9% for organic pollutants with molecular weight M exceeding 100 kDa.     

准好氧矿化垃圾床的装填密度研究

[目的]研究：位好氧矿化垃圾床的装填密度对渗滤液处理效果的影响。[方法]在实验室构建准好氧矿化垃圾床,通过测定COD、NH3-N和TN,比较分析不同装填密度反应床处理渗滤液的效果。[结果]当每立方矿化垃圾的水力负荷约45L／d、有机负荷约540g／d时,反应床对渗滤液中COD、NH3-N和TN的去除率分别达86％以上、92％以上和88％以上;当装填密度由1426kg／m^3减小到858kg／m^3时,渗滤液中COD、NH3-N和TN的去除率分别接近99％、100％和96％。根据不同装填密度反应床对渗滤液处理的效果和影响分析。初步确定试验奈件下准好氧矿化垃圾床适宜的装填密度为860kg／m^3。[结论]该研究可为准好氧矿化垃圾床的构建和应用提供定量化依据。     

运用Cl^-示踪研究回灌渗滤液的运移特性

通过模拟垃圾柱进行Cl-示踪试验,比较研究回灌渗滤液的运移特性和垃圾密度、厚度对其运移的影响。结果表明,渗滤液回灌后,分别以通道流和基质流2种流态运移,且在运移过程中不断与填埋垃圾中固有水分进行混合和交换,回灌渗滤液的流出是一个较长的过程;填埋垃圾压实密度和厚度越小,通道流作用越显著,示踪溶液和填埋垃圾中固有水分间的交换和混合作用越不明显。在实施渗滤液回灌的生物反应器填埋场中,应保证填埋垃圾的压实密度和厚度。