索氏提取-液相色谱法测定土壤中邻苯二甲酸酯类物质

采用索氏提取-固相萃取柱净化分离、高效液相色谱测定土壤中6种邻苯二甲酸酯类物质。利用正交试验对影响加标回收率的3个主要因素(萃取溶剂比例、萃取时间和萃取温度)进行了优化。方法回收率为95.3%～108.0%,相对标准偏差为0.83%～3.53%。并对实际土壤样品进行了测定。     

Composting of olive processing wastes and tomato stalks together with sewage sludge or dairy manure

In this study, composting of olive pomace from three-phase oil production system, sewage sludge, dairy manure, and tomato stalks were carried out. The effects of carbon/nitrogen ratio on decomposition rate of composting were investigated with constant free air spaces of composting mixtures. Composting process was carried out in the aerobic reactors made of stainless steel which were monitored for 32 days. Temperature-controlled feedback system was operated based on the Rutgers strategy. Temperature, moisture, organic matter, pH, electrical conductivity total carbon, total nitrogen, ammonium nitrogen and nitrate nitrogen, total phosphorus as well as potassium were monitored during the composting process. In addition, mass and volume changes of the mixtures were determined. The highest degree of decomposition was determined for the mixture (carbon/nitrogen ratio of 20) based on the dry matter loss where the maximum amount of sewage sludge was used. On the other hand, maximum decomposition occurred at a carbon/nitrogen ratio of 23 for mixtures containing dairy manure. The increase in the use of olive pomace in mixtures had adverse effects on the decomposition process. The stabilization process in the mixture containing dairy manure lasted shorter than the mixtures containing sewage sludge.     

Presence of fluoroquinolones and sulfonamides in urban sewage sludge and their degradation as a result of composting

The concentrations of some widely used pharmaceuticals, namely fluoroquinolones (ciprofloxacin C₁₇ H₁₈FN₃O₃, norfloxacin C₁₇ H₁₈FN₃O₃ and ofloxacin C₁₈ H₂₀FN₃O₄ and sulfonamides (sulfadimethoxine C₁₂ H₁₄N₄O₄s and sulfamethoxazole C₁₀ H₁₁N₃O₃S were determined in urban sewage sludge utilized for making compost. The levels of degradation of these pharmaceuticals resulting from sludge treatment were assessed. The concentrations of the studied pharmaceuticals sufficiently varied both in sewage sludge and in compost and due to this phenomenon the possible danger resulting from the presence of pharmaceuticals in sewage sludge, used for composting, can not be ignored. The concentrations of the studied pharmaceuticals were lower in compost, if compared to the relevant concentrations in sewage sludge. The highest pharmaceutical concentration in sewage sludge — 426 μg/kg — was detected in the case of ciprofloxacin. The highest concentrations present in compost were 22 μg/kg of norfloxacin and 20 μg/kg of ciprofloxacin. Results show that before using the sewage sludge for making compost or before using the compost a fertilizer for food plants, they should be carefully tested against the content of commonly used pharmaceuticals.     

Competitive adsorption of trace elements in calcareous soils as affected by sewage sludge,poultry manure,and municipal waste compost

The competitive adsorption of trace elements is a key issue in assessing the mobility of trace elements in calcareous soils and can be affected by disposal of sewage sludge, municipal waste, and poultry manure. The effect of municipal sewage sludge, poultry manure, and municipal waste compost on the sorption of cadmium (Cd), copper (Cu), zinc (Zn), and nickel (Ni) in surface samples of three calcareous soils was studied. As the applied concentrations increased, Cu and Cd adsorption increased, while Zn and Ni adsorption decreased in all treatments. Based on the distribution coefficient (K _d) values and proportion of increase or decrease in metal adsorption, the selectivity sequence in control and amended soils found was Cu ≫ Cd ≫ Ni > Zn and Cu ≫ Cd ≫ Zn > Ni, respectively. In general, among control and amended soils, control soils showed the highest K _d for Cd, Cu, and Ni, while sludge, poultry manure, and composted waste-amended soils had lowest K _d for Cd, Cu, and Ni, respectively. In the case of Zn, composted waste-amended and control soils had highest and lowest K _d, respectively. The present experimental results indicated that the addition of organic amendments to these calcareous soils reduced the sorption of Cd, Cu, and Ni. Thus, the effects of preferential adsorption and organic matter should be considered in assessing the risk associated with applying sewage sludge, poultry manure, and composted material to calcareous soils.     

Biodegradation of Cypermethrin by Pseudomonas in a batch activated sludge process

The biodegradation of Cypermethrin (20 to 125 mg/L) in an effluent using batch activated sludge was studied. Degradation was found to occur to a great extent only in the presence of Pseudomonas (IES-Ps-1) culture. Under aerobic conditions using mechanical aerators, Cypermethrin (20 mg/L) was almost completely degraded in just over 48 h at ambient temperature. Further loading of organic compound in subsequent experiments demonstrated that IES-PS-1was capable to degrade 82 % Cypermethrin at 40 mg/L dose in approximately 48 h. When the concentration was increased to 80 mg/L, 50% degradation of this compound was observed. Over this time period the cells could utilize only 17 % of Cypermethrin when it was given 125 mg/L, respectively. These findings indicate that increased concentration of Cypermethrin has a marked effect on biodegradation performance of IES-Ps-1 with a modest increased in the duration of lag phase, but did not lead to complete inhibition or cell death. These results proved that IES-Ps-1 is responsible for Cypermethrin degradation. Such finding may be useful in designing a scale-up in situ or on-site hazardous waste bioremediation process for field application.     

Biodegradation of anionic surfactants by isolated bacteria from activated sludge

Sodium dodecyl sulphate, (SDS) is an anionic surfactant that widely used all over the world. They will eventually end-up and accumulate in household or industrial sewage. Due to their high foaming capabilities, which can cause numerous problems in sewage treatment facilities as well as direct toxic effects on many different organisms in ecosystem; they are generally considered as serious pollutants. In this survey, two different bacteria were isolated from Tehran municipal activated sludge. Biochemical tests as well as 16S rRNA gene sequencing for identification have been applied. After experiments to optimize the pH and temperature for growth of the two bacterial isolates, the extent of SDS utilization was evaluated by HPLC method. Two bacterial isolates show which ability to rapidly and actively degrade SDS upon using it as their sole source of carbon. The identification tests have indicated the two isolates to be Acinetobacter johnsoni and Pseudomonas beteli. The Pseudomonas beteli and Acinetobacter johnsoni isolates were able to degrade 97.2% and 96.4% of the original SDS levels after 10 days of growth; respectively. Mixed culture of the two isolates did not significantly increase SDS utilization, (97.6%). In conclusion, the results of this study suggest that growth of simple bacteria such as Acinetobacter or Pseudomonas in household and industrial sewage can be cost-effective method anionic surfactants elimination.     

Appraisal of changes in sewage sludge management

A positive energy balance caused by accelerated production of CH₄ and additional financial benefits associated with shorter retention times, reduction in volumes, easier dewatering, enhanced hygiene, etc., are the reasons why most modern wastewater treatment plants are newly equipped with hydrothermal pretreatment units. This study examined how the changes in composition of the pretreated sewage sludge fermentation residues manifested themselves in subsequent processing by pyrolysis, both in terms of technology and financial impacts. It has been found that concentrations of heavy metals and other hazardous inhibitors might increase; however, the overall biotoxicity is lower due to their immobilization in the charred mass. Moreover, charring of the fermentation residues results in significant financial as well as technological benefits.     

The management of sewage sludge by the water industry in England and Wales

Summary The legislative framework within which the disposal of sewage sludge is managed in England and Wales and the methods employed are outlined. Those factors which affect management decisions are analysed and consideration is given to the environmental implications of those decisions. Sewage processes and sludge disposal are considered, and the problems, especially those of heavy metal contamination, are addressed. An indication is given as to how the Water Services Companies are likely to implement the more stringent controls on disposal. Finally, the future of sludge management in England and Wales is discussed.Abbreviations BAT Best available technology - BATNEEC Best available technology not entailing excessive cost - BOD₅ Biochemical oxygen demand - BPEO Best practicable environmental option - CBI Confederation of British Industry - CEST Centre for Exploitation of Science and Technology - COD Chemical oxygen demand - CSC Customer Services Committee - DAF Dissolved air flotation - DG Director General - DoE Department of the Environment - DS Dried solids     

高效液相色谱-荧光检测同时测定污泥中7种氟喹诺酮类抗生素

为了监测污泥中氟喹诺酮类抗生素(FQs)的含量和水平,建立了基于固相萃取高效液相色谱荧光检测法测定污泥中7种FQs的分析方法。污泥样品选用乙腈∶磷酸盐缓冲液(1∶1,V∶V)(pH=3)提取,以亲水亲油平衡(hydrophilic-lipophilic balance, HLB)小柱净化富集,经甲醇洗脱、浓缩后用高效液相色谱荧光检测器(HPLC-FLD)检测,采用乙腈/0.1%的甲酸作为流动相并以外标法定量。FQs在0.005～1.0 mg/L浓度范围内呈现良好线性关系,R2为0.992 7～0.999 8。添加量为0.05、0.5和1.0 mg/kg时,污泥中7种氟喹诺酮类的加标回收率为78.3%～106.4%,其相对标准偏差为3.68%～12.06%(N=5)。方法的检出限为0.001～0.01 mg/kg,方法定量限为0.004 6～0.038 4 mg/kg。用该方法对北京地区3个污水处理厂活性污泥样品中7种FQs进行分析,检出浓度范围为未检出至1.09 mg/kg。     

Accumulation of lead, cadmium, manganese, copper and zinc by sludge worms; Tubifex tubifex in sewage sludge

Tubifex tubifex has been shown to survive in organic polluted environments, however, not much has been done on its inorganic pollution tolerance. Samples of T. tubifex and their respective sewage sludge were taken from Soche wastewater treatment plant in Blantyre City, Malawi during July 2007 to November 2008. The total number of sludge samples taken was fifty one which was made into seventeen composite samples. A total of seventeen T. Tubifex samples were also collected. The samples were analyzed for copper, lead, manganese, zinc and cadmium using standard methods from American Public Health Association and Association of Official Analytical Chemists. The concentrations of metals in sewage sludge and T. tubifex were on dry weight basis and the metals determined were acid extractable. In general, heavy metals concentration was lower in T. tubifex than in sewage sludge. The range of heavy metals concentrations were (in sludge and (T. tubifex)): zinc 275.3–361.5 mg/kg (45.0–82.2 mg/kg), manganese 293.7–230.1 mg/kg (1.21–3.69 mg/kg), copper 86.5–120.1 mg/kg (1.6–4.7 mg/kg), lead 11.2–22.4 mg/kg (Below detection limit–0.95 ) and cadmium 1.12–2.31 mg/kg (1.08–2.18 mg/kg). The results showed significant differences between the concentrations of manganese, copper, lead and zinc in sewage sludge and T. tubifex (p < 0.05). However there was no significant difference between the concentrations of cadmium in sewage sludge and T. tubifex (p > 0.05). T. tubifex did not show the ability to accumulate heavy metals (attributed to its high defecation and metabolic rate) except for cadmium hence cannot be used as a bioindicator for heavy metal pollution in sludge.     

Immobilization of phosphorus in sewage sludge using inorganic amendments

Sewage sludge contains large amount of water-soluble phosphorus, which is prone to runoff loss when sewage sludge is land applied. Phosphorus export from sewage sludge is an important cause for water eutrophication. Immobilization of phosphorus before sewage sludge land application seems necessary. In this study, three amendments including red mud (RM), lime and mixture of RM and lime were employed to immobilize phosphorus in fresh sewage sludge. It was found that phosphorus was effectively controlled by RM, lime and mixture of RM and lime. Sequential chemical extraction results indicate that the RM amendment transformed H₂O-P in the sewage sludge into the NaOH-P, while the lime amendment transformed H₂O-P in the sewage sludge into the HCl-P. Such transformations in phosphorus fractions would have little influence on phosphorus availability but would retard and reduce potential phosphorus loss following sewage sludge was land applied.     

Soil improvement with coal ash and sewage sludge: a field experiment

A field experimental study was carried out successfully to improve the quality of the sandy soil by adding coal ash and sewage sludge. One ha of barren sandy soil field was chosen for the experiment in Shanghe County, Shandong Province, China. For soil amelioration and tree planting, two formulas of the mixture:coal ash, sewage sludge and soil, in ratios of 20:10:70 and 20:20:60, respectively, were used. Poplar trees were planted in pits filled with soils with additives (mixture of ash and sludge) as well as in the original sandy soil. In the 19th months after the trees were planted, the soils with additives were sampled and analyzed. The results show that the barren sandy soil was greatly improved after mixing with coal ash and sludge. The improved soils have remarkably higher nutrient concentrations, better texture, smaller bulk density, higher porosity and mass moisture content, and higher content of fine-grained minerals. During the first 22 months after planting, the annual increase in height of the trees grown in the soil with additives (4.78 m per year) was 55% higher than that of the control group (3.07 m per year), and the annual increase in diameter at the breast height (1.3 m) was 33 % higher (43.03 vs. 32.36 mm). Trees planted in soils with additives appeared healthier and shed leaves later than those in the control group. As the volume of the additives (30–40% in both formulas) is less than that of the sandy soil in and around the tree pits, it appears that the use of coal ash and sludge for tree planting and soil amelioration is environmentally safe even though the additives have relatively high heavy metal concentrations.     

污泥屏障渗透性及重金属阻截效果试验研究

目前,废弃物处置场渗滤液中的重金属污染物只能依靠极低渗透性的水力屏障来控制,还不存在利用化学场专门拦截重金属污染物的反应型屏障。在有机结合生活污泥的低渗透性与丰富的有机质和厌氧微生物特性的基础上,提出“污泥屏障”的构想。研究利用柔性壁渗透仪测量不同有效应力作用下生活污泥试样的渗透系数,并对渗出液的化学性质进行了监测,验证污泥屏障的可行性。试验结果表明：随着有效应力的增大,污泥试样干密度提高,渗透系数的对数值随孔隙比的减小线性降低。试样内部微生物厌氧呼吸形成的生物膜和无机物沉淀以及黏土颗粒双电层厚度的增大,也是污泥渗透系数降低的原因,污泥渗透系数仅为 数量级。另外,污泥强烈吸附能力及厌氧微生物呼吸作用形成的中-弱碱性还原环境,对渗透液中的Zn和Cd都起到了很好的拦截作用。     

Biodegradation of Cypermethrin by a newly isolated actinomycetes HU-S-01 from wastewater sludge

A new cypermethrin degrading strain was isolated from wastewater sludge using enrichment technique. On the basis of morphological, physiological, biochemical characteristics tests and 16S rDNA sequence analysis, the strain was determined to be a Streptomyces species, probably a strain of Streptomyces parvulus, so it was designated as Streptomyces sp. HU-S-01. The strain Streptomyces sp. HU-S-01 is aerobic and optimum growth temperature for the strain was found to be 26–28 °C with initial pH range 6.0-9.0 and pH 7.5 was found to be the optimum. This strain can also completely degrade 3-phenoxybenzoic acid within 96 h at the concentration of 50 mg/L. The kinetic constants Vmax, Km, Kcat and Kcat/ Km of enzyme for cypermethrin were 1.236 ?mol/min, 6.418 ?mol/mL, 13.493 min and 2.102 mL/mol.min, respectively. The degradation products of cypermethrin were identified using gas chromatographmass spectrometric (GC-MS) analysis. The degradation pathway followed by HU-S-01 involves oxidative as well as hydrolyzing. Biodegradation ability of strain Streptomyces sp. HU-S-01 without toxic byproducts reveals its potential for further study as a biological agent for the remediation of soil, water or crops, contaminated with cypermethrin.     

Optimization of sono-assisted dilute sulfuric acid process for simultaneous pretreatment and saccharification of rice straw

In this study, sono-assisted dilute sulfuric acid process was evaluated for its viability of simultaneous pretreatment and saccharification of rice straw. Three critical factors for simultaneous pretreatment and saccharification process, such as sonication time (30–50 min), temperature (70–90 °C), and acid concentration (5–10 %), were optimized to maximize reducing sugar yield using Box-Behnken design and response surface methodology. The response surface methodology model was found to be adequately fitted to the obtained data. Simultaneous pretreatment and saccharification factors were optimized at sonication of 50 min, 80 °C and an acid concentration of 10 % yielding the maximum sugar content (31.78 g/100 g of biomass). Scanning electron microscopy revealed that the smooth surface of raw biomass was altered into a rough and porous surface as a result of sugar release, which showed the prospective feasibility of simultaneous pretreatment and saccharification process. This process integration may lead to develop economical bioethanol production facility. However, further research is required to make this process industrially viable.     

Identification and fate of antibiotic residue degradation during composting and vermicomposting of chicken manure

Oxytetracycline (OCT) is a broad-spectrum antibiotic commonly used for broiler production to enhance growth and feeding efficacy. Concern has been expressed that the parent compounds of antibiotics such as OCT or their bioactive metabolites may be excreted through animal feces or urine with negative consequences for the environment when applied to agricultural lands. An integrated system involving a combination of thermophilic composting and vermicomposting using Eisenia fetida was investigated as a strategy for reducing the concentrations of oxytetracycline and its metabolites (4-epi-oxytetracycline [EOTC], α-apo-oxytetracycline [α-Apo-OTC] and β-apo-oxytetracycline [β-Apo-OTC]) in chicken manure. Treatments consisted of combinations of chicken manure and waste paper to produce waste mixtures with C: N ratios of 20, 30, 40, 50, 60 and 70 (T1, T2, T3, T4, T5 and T6, respectively). These were subjected to thermophilic composting for 20 days followed by vermicomposting with E. fetida for 7 weeks. The oxytetracycline concentration at the start of the experiment was in the range of 123.3–35.2 mg/kg, which reduced to 44–25.3 mg/kg after the thermophilic composting, and further reduced to 35.4–20.7 mg/kg at the end of the vermicomposting stage. The maximum overall percentage reduction of residual oxytetracycline in the final product was recorded in T3 (C:N ratio 40). The maximum percentage reduction of 84.3% was recorded in C: N ratio of 40 (T3) in which the metabolite degradation products were reduced to 3.1 mg/kg of 4-epi-oxytetracycline (EOTC), 3.9 mg/kg of α-apo-oxytetracycline (α-Apo-OTC) and 4 mg/kg of β-apo-oxytetracycline (β-Apo-OTC).     

Assessment of microbiological and biochemical properties of dairy sewage sludge

The rational utilisation of sludge as organic matter application into the soil permits enrichment in nutrients such as nitrogen and phosphorus. As dairy sewage sludge contains large amounts of organic matter and minerals, utilisation of such sludge in agriculture appears to be a noteworthy proposal. However, such waste can also be a source of toxic substances, heavy metals, inhibitors, xenobiotics and potentially pathogenic microorganisms. Therefore, it is so important to monitor its microbiological and biochemical properties in aspect of the safety for human health, natural environment preservation and a suitable level of agricultural production maintenance. The objective of study was the estimation of selected microbiological, biochemical and chemical properties of activated sludge (AS) and waste activated sludge (WAS) originating from the dairy sewage treatment plant. Nitrification and ammonification rates, respiratory, dehydrogenases, acid phosphatase, alkaline phosphatase, protease and urease activities were at significantly higher levels in the WAS than in the AS. The pH value of the AS and WAS oscillated within the range of neutral reaction.     

Ecotoxicological assessment of heavy metals in sewage sludge amended soils

Contamination of soils by potentially toxic elements (PTEs) (e.g. Zn, Cu, Ni, Cr, Pb, Cd) from amendments of sewage sludge is subject to strict controls within the European Community in relation to total permissible metal concentrations, soil properties and intended use. This paper highlights the need for ecotoxicological data for the assessment of PTE impacts in addition to geochemical data alone. The soil microflora plays an essential role in determining levels of soil fertility, being intimately associated with the biogeochemical cycling of essential plant nutrients and the turnover of organic carbon. The measurement of soil microbiological parameters can provide insight into the impact of PTEs upon soil fertility, where geochemical analysis alone can often be inadequate to assess contaminant effects on essential components of the soil ecosystem. Microbial investigations were conducted on soils sampled from a well-controlled field experiment previously amended with specific types and rates of sewage sludge. Key microbiological parameters measured included the activity of the dehydrogenase enzyme and the presence and number of effective nitrogen fixing cells of Rhizobium leguminosarum biovar trifolii capable of nodulating the host plant, white clover (Trifolium repens). Results were evaluated with respect to maximum permissible concentrations of PTEs in sludge amended soils, as stipulated under UK limit values and the European Directive 86/278/EEC. Important effects on the size of the Rhizobium population and dehydrogenase activity were apparent in soils samples in relation to the soil pH, sludge type, addition rates and the concentrations of PTE present.     

Reduction in chlorophenolic compounds during bleaching of rice straw pulp by replacing elemental chlorine with chlorine dioxide

Speedy running down of forest cover has put great stress on paper industry for finding new fibrous raw materials. Rice straw is an abundantly available lignocellulosic material especially in wood-short countries and can be utilized as an alternate fibre resource by paper mills. Bleaching is a crucial step in papermaking that involves the chemical reactions to reduce the colour of the pulp and makes it brighter for manufacturing writing and printing grade paper. Contrary to this, bleaching results into the formation of toxic, biorefractory and carcinogenic chlorolignin compounds that pose serious health hazards to aquatic life and human beings. A study was carried out using rice straw soda-AQ pulp for bleaching with sequence based on elemental chlorine (CE_OPHH). Further, to reduce the wastewater pollution load, emphasis was given on replacement of elemental chlorine with chlorine dioxide at the first bleaching stage (C_D10E_OPHH C_D30E_OPHH and C_D50E_OPHH) and elemental chlorine-free (ECF) bleaching (DE_OPD). The study revealed that generation of chlorophenolic compounds was the highest in CE_OPHH sequence followed by C_D10E_OPHH C_D30E_OPHH and C_D50E_OPHH, i.e. 6047, 4765, 4247 and 3864 mg/t, respectively. In DE_OPD bleaching sequence, the generation of chlorophenolic compounds in wastewater was reduced to 421 mg/t. ECF bleaching had major impacts on reduction in chloroguaiacols (97%) and chlorophenols (92%) that were in the highest quantity in effluents of CE_OPHH bleaching sequence. DE_OPD bleaching was found to be a promising option for pulp and paper industry for cutting down the generation of chlorophenolic compounds in bleaching effluents.