城市生活垃圾堆肥处理工程技术发展探讨

文章分析了我国城市生活垃圾堆肥陷入滞销困境多年的原因，指出摆脱这一困境的技术途径是要大幅度提高堆肥品质。而要实现这一目标，首先必须引进先进的堆肥翻堆技术，缩短腐熟时间，提高腐熟度；其次是应用气流密度分选系统对粗堆肥进行精分选。     

堆肥中腐熟污泥替代外源添加剂的研究

本文对用腐熟污泥替代木屑等外源添加剂高温好氧堆肥作了研究。通过腐熟污泥回流三次的堆肥结果显示,每次回流的堆肥温度都能在55℃以上保持5天以上,达到无害化的要求,含水率都能降到45％左右,污泥的有机物降解率相近,pH在6～9之间。需要注意的是腐熟污泥多次回流中重金属浓度有个增加的过程,达到峰值后逐渐下降。     

油气田污泥无害化处理途径探讨

我国污泥处理和处置研究起步较晚,大部分为农田堆肥处置,这对环境保护有不良的影响。在室内进行了油田污泥固化试验研究。研究结果表明:水泥固化污泥可用于制作筑路材料,以水泥、石灰、水玻璃为主要固化剂的污泥可进行填埋处理,含油污泥可制成煤球,可将含油污泥焚烧处理,可以用污泥焚烧灰制砖。这些方法都是污泥后续无害化、资源化处理的有效手段。     

城市垃圾和污水脱水污泥、排水管污泥混合堆肥工艺研究

城市垃圾和污水脱水污染、排水管污泥已成为现代城市污染的主要总是。由于这些废弃物中有机物质的含量较高,因此可以利用堆肥的方法来进行处理,使其转化为农田的有机肥料,本文用城市生活垃圾和污水处理厂污泥、排水管污泥混合进行堆肥的研究。     

城市污水处理厂污泥制肥技术

由山西沃土生物有限公司开发、山西省环保局推荐的污泥制肥技术适用于城市生活污水处理厂。 主要技术内容:一、基本原理:依据生物发酵、复合营养及土壤健康的理论,包括:污泥软化技术,变完全絮凝为半絮凝,缓解城市生活污水污泥在絮凝过程中的不溶解缺陷;利用堆积发酵工艺,加入磷酸溶解性材料和重金     

城市生活垃圾的堆肥研究

城市生活垃圾经动态式堆肥翻堆机处理制成腐熟堆肥，并最终试制成有机复混颗粒肥，二者先后在茶树、数种花卉作物和数种叶菜类蔬菜上进行田间试验，证明有较好的肥效，且成本较低廉，在农业生产上有实际应用的价值。从环境保护角度上看：这种方法是将城市生活垃圾转化为资源化、无害化的一项有意义的举措。     

城市污泥园林景观砖的制备及性能研究

以城市污泥为部分原料,页岩、黏土等作为掺料,进行了污泥制园林景观砖的实验研究,探讨了烧结时间和污泥掺量等条件对污泥黏土砖质量减少分数、烧成密度等性能的影响.实验结果表明,当污泥总量占总体质量的5％,烧结温度在1000℃左右,煅烧过程持续6 h左右时,制作的砖体质量轻,砖体密度相对较低,抗压强度相对最大,而且污泥和黏土的...     

城市污水处理厂污泥利用探讨

采用在污水污泥中按不同比例掺入生活垃圾或黄土与砂,进行高温堆制,开发出含多种微量元素的高效有机／无机复合肥和多微有机营养土,并施用于农作物和花卉。结果表明施用后农作物产量增加,花卉植物的株高、花蕾数、根长、根重明显高于对照组。该课题的研究不仅可获得廉价的微量元素复合肥料,而且消除了污水污泥对环境的污染,可创造一定的社会经济效益。     

日本污泥制肥行业标准及市场运营案例

介绍了日本污泥制肥行业概况,通过对相关标准体系和秋田市污泥堆肥中心运营状况的研究,对我国的污泥制肥行业发展提出了建议。     

污泥土地利用生态风险评价初探

生态风险评价是污泥环境风险评价的重要组成部分。本文通过对美国污泥土地利用生态风险评价的研究，阐述了污泥土地利用生态风险评价过程中涉及的基本概念和定量研究方法，并对存在的困难进行了探讨。文章建议我国应借鉴国外污泥土地利用生态风险评价的研究方法，尽快建立适合我国污泥处置的生态风险评价标准方法和指南，以发挥其在环境保护和管理中的作用。     

Comparison of heavy metals content in compost against vermicompost of organic solid waste: Past and present

Disposal of the municipal organic solid waste is a serious problem worldwide. Composting is one of the most preferred methods of solid waste management practice, principally due to the high percentage of organic material in the waste composition. Composting has advantages over land-filling and incineration in Mauritius because of lower operational costs, less environmental pollution, beneficial use of the end product, high humidity and organic content of household waste. Vermicomposting is a comparatively enhanced method in composting, and involves the stabilization of organic solid waste through earthworm consumption that converts the waste into earthworm castings. In both composting and vermicomposting processes, the presence of heavy metals and different toxics substances limits its land use without processing. The production and application of compost potentially contaminate the environment with heavy metals. There is a high-degree of consensus in the past and present literatures that composting increases metal concentrations but whether similar changes in metal concentration and availability occur during vermicomposting has not been fully resolved. This review deals with various total metal contents present in composting compared to that present in vermicomposting of organic solid wastes from past and present years.     

Manure phosphorus extractability as affected by aluminum- and iron by-products and aerobic composting

Shifts in manure phosphorus (P) chemical forms and pool sizes induced by water treatment residuals and industrial mineral by-products are largely undefined. We conducted a manure P fractionation study to determine mechanisms of reduction of dissolved reactive phosphorus (DRP) in poultry manure upon mineral by-product additions. The effects of composting on the P immobilization efficacy of the by-products were determined using laboratory self-heating composting simulators. The mineral by-products included an aluminum-water treatment residual (Al-WTR) and an iron-rich titanium-processing by-product. The noncomposted manure averaged 0.11 g g(-1) of total P as DRP forms. The by-products significantly reduced manure DRP, by an average of 39 and 48% in the Al- and the Fe-treated manure, respectively. The by-products also reduced the 0.5 M NH4F-extractable phosphorus (FEP) fraction. Shifts in P forms between FEP and 0.1 M NaOH-extractable phosphorus (SHEP) depended upon the Al and Fe contents of the by-products while the combined FEP + SHEP pool remained constant. Phosphate sorption measurements supported the observations that the Fe-rich by-product was more effective at reducing manure DRP and enhancing the formation of SHEP forms at the expense of FEP than the Al-WTR. Composting had no effect on the efficacy of either by-product to reduce DRP. Potential mechanisms of enhanced P stabilization in treated manure upon composting included chemical shifts from the DRP and FEP fractions to the citrate-bicarbonate-dithionite extractable P fraction. Thus, the choice of P immobilization agents affected the stability of immobilized P forms and should be taken into consideration in developing manure processing and nutrient stabilization methods.     

Effect of chemical and microbial amendments on ammonia volatilization from composting poultry litter

Research has shown that aluminum sulfate (alum) and phosphoric acid greatly reduce ammonia (NH3) volatilization from poultry litter; however, no studies have yet reported the effects of these amendments on field-scale composting of poultry litter. The objectives of this study were to (i) evaluate NH3 volatilization from composting litter by measuring both NH3 volatilization and changes in total nitrogen (N) in the litter and (ii) evaluate potential methods of reducing NH3 losses from composting poultry litter. Poultry litter was composted for 68 d the first year and 92 d the second year. Eleven treatments were screened in Year 1, which included an unamended control, a microbial mixture, a microbial mixture with 5% alum incorporated into the litter, 5 and 10% alum rates either surface-applied or incorporated, and 1 and 2% phosphoric acid rates either surface-applied or incorporated. Treatments in Year 2 included an unamended control, a microbial mixture, alum (7% by fresh wt.), and phosphoric acid (1.5% by fresh wt.). Alum and phosphoric acid reduced NH3 volatilization from composting poultry litter by as much as 76 and 54%, respectively. The highest NH3 emission rates were from microbial treatments each year. Compost treated with chemical amendments retained more initial N than all other treatments. Due to the cost and N loss associated with composting poultry litter, composting is not economical from an agronomic perspective compared with the use of fresh poultry litter.     

Biological aspects of metal waste reclamation with biosolids

Smelter waste deposits pose an environmental threat worldwide. Biosolids are potentialy useful in reclamation of such sites. Biological aspects of revegetation of Zn and Pb smelter wastelands using biosolids are discussed in this report. The goal of the studies was to assess to what extent biosolid treatment would support ecosystem functioning as measured by biological indicators such as enzyme activities of revegetated metal waste or plant growth. Another crucial aspect was related to the assessment of metal transfer to the ecosystem which could affect the health of local fauna and also create a food chain risk. A field experiment was conducted on a smelter waste deposit in Piekary Slaskie, Silesia, Poland, with two separate fields - established on wastes from the Welz and Doerschel smelting processes. The tested methods allowed revegetation of the fields - application of municipal biosolid at the rate 300 dry t ha(-1) combined with the incorporation of commercial lime in a mixed oxide and carbonate form at the rate of 1.5 and 30 t for Welz waste or use of a 30 cm by-product lime cap followed by incorporation of biosolid at a rate of 300 t ha(-1) for the more acidic Doerschel waste. Studies on biological activities demonstrated that the reclamation methods used are an effective way to establish new, fully-functioning ecosystems that support plant growth. They also provided strong evidence that forage crops grown on Zn, Cd and Pb contaminated sites reclaimed using lime and biosolids do not pose identified risk for wildlife and food safety.     

Carbon paste electrodes modified with biosolids, soils and biocomposites utilized to study the interaction between organic matter and copper

Carbon paste electrodes (CPEs) modified with a biosolid, two types of soils with different amounts of organic matter (OM), and two biocomposites (soils mixed with a biosolid) were used to assess and compare the Cu(II) ion retention properties of the organic matter contained in the samples. The accumulation of Cu(II) on the surface of the modified carbon paste electrodes (MCPEs) was performed under open-circuit conditions. When comparing the response of the MCPEs while assessing parameters such as pH, preconcentration time, and adsorption/desorption capacity, it was found that the reaction mechanism of the two soils is different between the soils and dissimilar from the biosolid; while the biocomposites show reaction mechanisms that are intermediate between those of the soils and the biosolid. This was proven with the use of infrared spectroscopy, since the FTIR spectra show similarities between the two soils and significant differences between the soils and the biosolid.     

Biosolid colloid-mediated transport of copper, zinc, and lead in waste-amended soils

Increasing land applications of biosolid wastes as soil amendments have raised concerns about potential toxic effects of associated metals on the environment. This study investigated the ability of biosolid colloids to transport metals associated with organic waste amendments through subsurface soil environments with leaching experiments involving undisturbed soil monoliths. Biosolid colloids were fractionated from a lime-stabilized, an aerobically digested, and a poultry manure organic waste and applied onto the monoliths at a rate of 0.7 cm/h. Eluents were monitored for Cu, Zn, Pb, and colloid concentrations over 16 to 24 pore volumes of leaching. Mass-balance calculations indicated significantly higher (up to 77 times) metal elutions in association with the biosolid colloids in both total and soluble fractions over the control treatments. Eluted metal loads varied with metal, colloid, and soil type, following the sequences Zn = Cu > Pb, and ADB > PMB > LSB colloids. Colloid and metal elution was enhanced by decreasing pH and colloid size, and increasing soil macroporosity and organic matter content. Breakthrough curves were mostly irregular, showing several maxima and minima as a result of preferential macropore flow and multiple clogging and flushing cycles. Soil- and colloid-metal sorption affinities were not reliable predictors of metal attenuation/elution loads, underscoring the dynamic nature of transport processes. The findings demonstrate the important role of biosolid colloids as contaminant carriers and the significant risk they pose, if unaccounted, for soil and ground water contamination in areas receiving heavy applications of biosolid waste amendments.     

Effect of chloride in soil solution on the plant availability of biosolid-borne cadmium

Increasing chloride (Cl) concentration in soil solution has been shown to increase cadmium (Cd) concentration in soil solution and Cd uptake by plants, when grown in phosphate fertilizer- or biosolid-amended soils. However, previous experiments did not distinguish between the effect of Cl on biosolid-borne Cd compared with soil-borne Cd inherited from previous fertilizer history. A factorial pot experiment was conducted with biosolid application rates of 0, 20, 40, and 80 g biosolids kg(-1) and Cl concentration in soil solution ranging from 1 to 160 mM Cl. The Cd uptake of wheat (Triticum aestivum L. cv. Halberd) was measured and major cations and anions in soil solution were determined. Cadmium speciation in soil solution was calculated using GEOCHEM-PC. The Cd concentration in plant shoots and soil solution increased with biosolid application rates up to 40 g kg(-1), but decreased slightly in the 80 g kg(-1) biosolid treatment. Across biosolid application rates, the Cd concentration in soil solution and plant shoots was positively correlated with the Cl concentration in soil solution. This suggests that biosolid-borne Cd is also mobilized by chloride ligands in soil solution. The soil solution CdCl+ activity correlated best with the Cd uptake of plants, although little of the variation in plant Cd concentrations was explained by activity of CdCl+ in higher sludge treatments. It was concluded that chlorocomplexation of Cd increased the phytoavailability of biosolid-borne Cd to a similar degree as soil (fertilizer) Cd. There was a nonlinear increase in plant uptake and solubility of Cd in biosolid-amended soils, with highest plant Cd found at the 40 g kg(-1) rate of biosolid application, and higher rates (80 g kg(-1)) producing lower plant Cd uptake and lower Cd solubility in soil. This is postulated to be a result of Cd retention by CaCO3 formed as a result of the high alkalinity induced by biosolid application.     

城市生活垃圾堆肥厂中的除臭技术

本文分析了垃圾堆肥厂臭气的来源，臭气的成份，介绍了脱臭技术及其设计参数，提出了在垃圾堆肥厂的设计建设中应重视臭气污染，除臭设施应同步建设的观点。     

Degradation of biomacromolecules during high-rate composting of wheat straw-amended feces

Pig (Sus scrofa) feces, separately collected and amended with wheat straw, was composted in a tunnel reactor connected with a cooler. The composting process was monitored for 4 wk and the degradation of organic matter was studied by two chemical extraction methods, 13C cross polarization magic angle spinning (CPMAS) nuclear magnetic resonance (NMR) and pyrolysis gas chromatography-mass spectrometry (GC-MS). Wet-chemical extraction methods were not adequate to study the degradation of specific organic compounds as the extraction reagents did not give selective separation of hemicellulose, cellulose, proteins, and lignins. A new method was proposed to calculate the contribution of four biomacromolecules (aliphatics, proteins, polysaccharides, and lignin) from the 13C CPMAS NMR spectrum. Pyrolysis GC-MS allowed identification of the composition of the biomacromolecules. The biomacromolecules showed different rates of degradation during composting. High initial degradation rates of aliphatics, hemicellulose, and proteins were observed, where aliphatics were completely degraded and hemicellulose and proteins were partly recalcitrant during the four weeks of composting. The degradation rate of cellulose was much lower and degradation was not completed within the four weeks of composting. Lignin was not degraded during the thermophilic stage of composting but started to degrade slowly during the mesophilic stage. A combination of 13C CPMAS NMR and pyrolysis GC-MS gave good qualitative and semiquantitative assessments of the degradation of biomacromolecules during composting.     

Using data mining to predict soil quality after application of biosolids in agriculture

The amount of biosolids recycled in agriculture has steadily increased during the last decades. However, few models are available to predict the accompanying risks, mainly due to the presence of trace element and organic contaminants, and benefits for soil fertility of their application. This paper deals with using data mining to assess the benefits and risks of biosolids application in agriculture. The analyzed data come from a 10-yr field experiment in northeast France focusing on the effects of biosolid application and mineral fertilization on soil fertility and contamination. Biosolids were applied at agriculturally recommended rates. Biosolids had a significant effect on soil fertility, causing in particular a persistent increase in plant-available phosphorus (P) relative to plots receiving mineral fertilizer. However, soil fertility at seeding and crop management method had greater effects than biosolid application on soil fertility at harvest, especially soil nitrogen (N) content. Levels of trace elements and organic contaminants in soils remained below legal threshold values. Levels of extractable metals correlated more strongly than total metal levels with other factors. Levels of organic contaminants, particularly polycyclic aromatic hydrocarbons, were linked to total metal levels in biosolids and treated soil. This study confirmed that biosolid application at rates recommended for agriculture is a safe option for increasing soil fertility. However, the quality of the biosolids selected has to be taken into account. The results also indicate the power of data mining in examining links between parameters in complex data sets.