陈垃圾特性分析及其适应性评价

对深圳市盐田区垃圾场处置工程陈垃圾特性进行了分析，结果表明，场内陈垃圾已基本腐熟，相对附近农田土壤，陈垃圾中的营养物质较高，接近但尚未完全达到农用垃圾肥标准，且铅含量超标２～３倍，不宜进入食物链。但陈垃圾可用作市区绿化地带、公园、苗圃、林业等处的有机肥和垃圾填埋场封场工程的表层营养上。     

陈垃圾沉降分析方法及工程应用

已填垃圾的沉降分析是正确评估填埋场服务年限和合理确定填埋厚度的重要依据,根据陈垃圾的形成机制、沉降模型、计算方法以及及有关参数,并结合工程实例对填埋过程中的垃圾沉降发展过程进行了研究,确定了陈垃圾土的沉降特性。     

上海老港生活垃圾填埋场陈垃圾的基本特性研究

对上海老港生活垃圾填埋场6年填埋龄和10年填埋龄陈垃圾的基本特征进行了测试研究，这些特性包括粒径分布，臭味、微生物数量、含水率、总磷、总氮、饱和水力渗透系数等。研究结果：上海老港生活垃圾填埋场中6年以上填埋龄陈垃圾已可以开采用使用；对其多种用途的开发主要限于陈垃圾中粒径小于15mm的细料部分；此细料是极为优良的污染物生物处理基质。     

西海堤垃圾场和西田垃圾场陈垃圾特性研究

结合深圳市宝安区西海堤垃圾场和西田垃圾场现场实验，分析了陈垃圾的物理成分，并将其与新鲜垃圾物理成分作对比，得出易降解有机物含量、塑胶含量和无机物含量与陈垃圾稳定化的关系。     

生活垃圾填埋场陈垃圾基本特性及再利用

填埋场已填埋陈垃圾具有丰富的资源 ,我国填埋量已达几千万吨。通过对上海老港生活垃圾填埋场 6年填埋龄和 1 0年填埋龄陈垃圾基本特性的测试研究 ,揭示出填埋 6年以上的陈垃圾已具有相当稳定的性状 ,原始垃圾特征已完全消失 ,开挖后没有异味 ,在组成上除部分大颗粒无机物和大块难降解有机物外 ,其余部分已腐化为类土壤物质 ,可以开采再利用。陈垃圾中类土壤部分在物理化学性质、水力学和微生物学性质上均表现出在自然条件下难以形成的、极为优良的基质特征 ,可用作污染物生物处理基质或作物培育基质。     

垃圾渗滤液处理技术特点简析及发展趋势

城市垃圾渗滤液是一种成分复杂，有机物、氨氮浓度高的难处理废水。介绍了国内外垃圾渗滤液处理技术应用现状，并结合工程实例以及处理效果予以简要分析、评价，在此基础上提出了国内垃圾渗滤液处理的发展趋势。     

长沙市医疗垃圾管理处置状况及特性研究

报道了对长沙市5所医院为期一个月的研究结果，内容包括：医疗垃圾管理处置现状；医疗垃圾类型及产量；门诊人数、住院人数及垃圾量的变化规律；住院病人和门诊病人的垃圾产率及中药渣产率；传染性垃圾与生活垃圾的比例及医疗垃圾的组成，指出了现行医疗垃圾管理处置需要改进和提高之处，为建立长沙市医疗垃圾集中处理示范工程提供了依据。     

不同载体生物滤池对渗滤液污染物的处理效果

以陈垃圾和煤渣作为生物滤池反应器填料,分别构建了单一陈垃圾、煤渣以及复合该2种填料的生物反应器,对渗滤液中的污染物进行了去除效果实验.结果表明,煤渣生物滤池对于渗滤液中COD和氨氮的去除效果高于陈垃圾滤池,但是总氮的去除率低于陈垃圾.复合填料滤池对于负荷和低温变化具有较好的耐受能力.电镜观察和微生物计数结果表明,2种载体适合微生物挂膜生长.粒径分析结果表明,2种载体的颗粒粒径组成对于滤池通透性能以及污染物去除有重要影响.     

垃圾渗滤液回用工程工艺设计

南方某城市垃圾填埋场为解决垃圾渗滤液污染环境和生产杂用水短缺问题，建设了垃圾渗滤液回用工程。该工程处理工艺采用物化＋SBR＋反渗透技术，出水水质达到了生产杂用的水质要求，取得了良好的社会效益和经济效益。介绍了工程的工艺流程、设计参数及设计特点。     

我国城市垃圾管理现状和问题

目前我国城市垃圾管理呈现出不可持续的态式。伴随着经济高速发展和城市化进程不断加快，城市垃圾数量不断增加，而这又给我国垃圾管理带来了更大的压力。由于制度缺陷和缺少人力资源及资本，城市管理部门难以对所有垃圾回收处理，导致我国许多城市垃圾常年暴露在外甚至向河流、湖泊倾倒，危害人身健康和环境质量。从我国城市垃圾管理体系、垃圾管理政策、垃圾生成和成分、垃圾收集、循环利用、垃圾处置、垃圾管理技术和管理成本等方面描述了我国城市垃圾管理的现状和问题。     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis （DGGE） and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity （both in gene richness and diversity index values） and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor （50 mg/kg） recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos （150 mg/kg） caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos （250 mg/kg） produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes （bands） responded differently to the impact of agrochemicals： four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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Organochlorine pesticides in soils under different land usage in the Taihu Lake region, China

A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides (OCPs) were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX (DDD, DDE and DDT) had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p'-(DDD DDE)/DDT in soils under three land usages were: paddy field ＞ tree land ＞ fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p'-(DDD DDE)/DDT ＞1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.     

Single and joint effects of pesticides and mercury on soil urease

The influence of two pesticides including chlorimuron-ethyl and furadan and mercury （Hg） on urease activity in 4 soils （meadow burozem and phaeozem） was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase （up to 13%-21%） in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship （P〈0.05） between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose （ED50） values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.     

Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.     

Alterations of organ histopathology and metallolhionein mRNA expression in silver barb, Puntius gonionotus during subchronic cadmium exposure

Common silver barb,Puntius gonionotus,exposed to the nominal concentration of 0.06 mg/L Cd for 60 d,were assessed for histopathological alterations(gills,liver and kidney),metal accumulation,and metallothionein(MT)mRNA expression.Fish exhibited pathological symptoms such as hypertrophy and hyperplasia of primary and secondary gill lamellae,vacuolization in hepatocytes,and prominent tubular and glomerular damage in the kidney.In addition,kidney accumulated the highest content of cadmium,more than gills and liver.Expression of MT mRNA was increased in both liver and kidney of treated fish.Hepatic MT levels remained high after fish were removed to Cd-free water.In contrast,MT expression in kidney was peaked after 28 d of treatment and drastically dropped when fish were removed to Cd-free water.The high concentrations of Cd in hepatic tissues indicated an accumulation site or permanent damage on this tissue.     

Sorption of 1-naphthol by plant cuticular fractions

The contribution of aliphatic-rich plant biopolymer to sorption of hydrophobic organic compounds is significantly important because of their preservation and accumulation in the soil environment,but sorption mechanism is still not fully understood.In this study, sorption of 1-naphthol by plant cuticular fractions was examined to better understand the contributions of respective fraction.Toward this end,cuticular materials were isolated from the fruits of tomato by chemical method.The tomato cuticle sheet consisted of waxes (6.5 wt%),cuticular monomer (69.5 wt%),and polysaccharide (24.0 wt%).Isotherms of l-naphthol to the cuticular fractions were nonlinear (N value (0.82-0.90)) at the whole tested concentration ranges.The KodKow ratios for bulk cuticle (TC1),dewaxed cuticle (TC2),cutin (TC4),and desugared cuticle (TC5) were larger than unity,suggested that tomato bulk cuticle and cutin are much powerful solption medium.Sorption capability of cutin (TC4) was 2.4 times higher than the nonsaponifiable fraction (TC3).The 1-naphthol interactions with tomato cuticular materials were governed by both hydrophobic-type interactions and polar (H-bonding) interactions. Removal of the wax and polysaccharide materials from the bulk tomato cuticle caused a significant increase in the sorption ability of the cuticular material.There was a linear negative trend between K_(oc) values and the amount of polysaccharides or fraction's polarities ((N O)/C);while a linear positive relationship between K_(oc) values and the content of cutin monomer (linear R~2=0.993) was observed for present in the cuticular fractions.Predominant sorbent of the hydrophobic organic compounds (HOCs) in the plant cuticular fraction was the cutin monomer,contributing to 91.7% of the total sorption of tomato bulk cuticle.     

Seed selections for crystallization of calcium phosphate for phosphorus recovery

Seed induces and promotes the crystallization of calcium phosphate, and acts as carrier of the recovered phosphorus （P）. In order to select suitable seed for P recovery from wastewater, three seeds including Apatite （AP）, Juraperle （JP） and phosphate-modified Juraperle （M-JP） were tested and compared. Batch and fixed-bed column experiments of seeded crystallization of calcium phosphate were undertaken by using synthetic wastewater with 10 mg/L P phosphate. It shows that AP has bad enduring property in the crystallization process, while JP has better performance for multiple uses, and M-JP is a hopeful seed for P recovery by crystallization of calcium phosphate.