Evaluation of Consortia of Microorganisms for Efficient Removal of Hexavalent Chromium from Industrial Wastewater

The Chromium (Cr) uptake ability of Cr-resistant bacterium Bacillus thuringiensis, yeast Candida etschellsii, and a protozoan Stylonychia mytilus, isolated from industrial waste water, was evaluated individually and in different combinations. It was found that the three types of microorganisms grown together in a culture medium could collectively uptake 90% of Cr⁶⁺ from the culture medium as against 82% by bacterium + protozoan or yeast + protozoan combined culture, each. Consortium of bacterium, yeast and ciliates therefore could make much more efficient inoculum for remediation of Cr-contaminated industrial waste water.     

Microbial quality of clinical waste from hospitals processed by microwave technology

As the costs, both fiscal and political, of clinical waste incineration spiral upwards, alternative technologies for the treatment of the bulk fraction of clinical waste are being evaluated. A process utilizing microwave energy to pasteurize clinical waste has recently been introduced to the UK market. In order to evaluate the process in terms of environmental impact, microbiological efficacy and to determine processing costs, a study using a mobile unit was undertaken at Stirling Royal Infirmary, Stirling, Scotland. The results indicate that the unit has no adverse environmental impacts and is an efficient pasteurizer, reducing total aerobic counts by 2–3 logs and sporeforming organisms on average 2 logs. Processing capacity was lower than expected at 180–200 kg h^‐1 and processing costs depended on the percentage utilization ranging from £340 t^‐1 at 20% utilization to £145 at 84% utilization.     

Molecular detection, quantification and characterization of human polyomavirus JC from waste water in Rio De Janeiro, Brazil

Polyomavirus JC (JCPyV) is largely excreted by the human population through the urinary route and has been recognized as a potential viral marker for human waste contamination. This study aims to investigate the dissemination of JCPyV in waste water from a sewage treatment plant (STP) located in Rio de Janeiro, Brazil, and to describe the prevalence of JCPyV subtypes currently present in this population. Raw and treated sewage samples were collected bimonthly during one year, and examined for the presence of JCPyV using nested polymerase chain reaction (nPCR) and quantitative real time PCR (qPCR). JCPyV was detected by nPCR in 96% and 43% of raw and treated sewage samples, respectively. The concentration of JCPyV present in the samples ranged from 1.2 × 10³ to 3.2 × 10⁵ and 2.6 × 10² to 6.2 × 10³ genome copies per 2 ml of concentrated raw and treated sewage sample, respectively. The strains were characterized and the obtained nucleotide sequences indicated that the detected JCPyV strains clustered with subtypes of East African, West African and European origin. To our knowledge, this is the first study describing the incidence and diversity of JCPyV strains in raw and treated sewage in Brazil.     

Efficiency of solar water disinfection photocatalized by titanium dioxide of varying particle size

Titanium dioxide photocatalysed water disinfection is induced by the interaction of light with TiO₂, which generates highly reactive free hydroxyl radicals (OH^•). These free radicals create lethal damage that leads to bacterial death. Normally, decreasing TiO₂ particle size increases the area of light interaction. This may possibly increase the concentration of OH^• generated and hence increases disinfection efficiency. Moreover, decreasing the particle size increases the force of attraction between the particles and cells, which could create aggregates that may contribute to the local OH^• concentration. In the present investigation cells of Escherichia coli were used as the test microorganism, TiO₂ as the photocatalyst and sunlight as the light source. Four different surface areas of TiO₂ particles corresponding to 10, 50, 80–100 and 300 m² g^-1 were tested at a concentration of 1 g l^-1. Disinfection efficiency increased with increasing the surface area producing a maximum between 80–100 m² g^-1 followed by a reduction at 300 m² g^-1. The reduction in the efficiency at this relatively high surface area was attributed to the increase in the local concentration of OH^•. This increase may be high enough to initiate radical-radical interaction that would compete with bacterial cells and reduce the chance of bacterial cell-radical interaction taking place. Moreover, the phenomenon of TiO₂ aggregation with bacterial cells plays an important role, and the extent of aggregation increases with decreasing particle size. Such aggregation could augment the concentration of OH^• within the cell vicinity. This suggests that surface area is a key factor in determining the efficiency of disinfection, and that concentration is a vital factor.     

Water quality characteristics associated with fluorite mining in the Kerio Valley area of Western Kenya

The extent to which fluorite mining and the disposal of mine waste influence surface‐ and groundwater quality in the Kerio Valley area is evaluated. Several hydrochemical parameters and their interrelationships were determined to identify pollution types and their sources. Adsorption and complex formation are shown to be important processes governing the behaviour of metals and organic constituents in these waters; the dissolved metal fraction is consequently often low and of limited toxicological significance. In addition to the now well‐established dental and skeletal conditions associated with fluoride excess in these waters, the prevalence of the goitrous condition is reported and its origin discussed. The level of nutrients (NO₃ ^‐, PO₄ ^3‐ and SO² ₄ ^‐) are well below their respective critical limits for eutrophication. Because of the relatively high rate of soil erosion and leaching of associated bedrock, however, rather elevated values are found for total dissolved solids (TDS) and electrical conductivity (EC). Biochemical oxygen demand (BOD) is up to five times the maximum permissible drinking water limit, but other indicators of organic pollution such as chemical oxygen demand (COD) and NO₃‐N are well below their recommended thresholds for drinking water.     

浅谈新形势下医院废水及医疗废物管理现状及对策

文章针对我国部分地区遭受突如其来的非典型肺炎袭击，对医院废水及医疗废物处理等管理工作暴露出来的一系列问题进行研究分析。充分认识到医院废水及医疗废物管理是医院当前和今后管理工作的重要组成部分，是医院经济可持续发展战略的重要保证，是医疗卫生机构不可忽视的重要工作。做好新形势下医院废水及医疗废物管理工作：一要靠政府部门的大力支持和监督；二是医疗卫生机构各级领导要高废重视；三要加强环境保护法的宣传学习，增强法制观念；四要加强医疗环境保护基础设施的投入，实行医疗废物产业化管理，将医院废水及医疗废物的管理工作纳入规范化、制度化、科学化、法制化管理的轨道。     

Exposure to Organic Dusts,Endotoxins, and Microorganisms in the Municipal Waste Industry

Abstract

The waste-collection and -processing industry in Europe is developing rapidly due to environmental constraints in the direction of separate collection, processing, and recycling of waste. It is likely that this will lead to an increase in the number of workers involved in the handling and processing of municipal waste, and an increase in the number of workers exposed to organic dust. This paper reports the results of an occupational hygiene study of the waste-collection and -processing industry (a compost-screening facility, a resource recovery facility, and two waste-transfer facilities) in The Netherlands. It focuses on organic dusts, endotoxins, and microorganisms (total and gram-negative bacteria and fungi). Levels of exposure to inhalable organic dusts were highest in the waste-processing facilities (compost screening and resource recovery), with average concentrations for organic dusts up to 14.3 mg/m³ during manual separation of waste and 9.7 mg/m³ during compost screening activities. Personal endotoxin exposure was highest in the resource-recovery facility, ranging from 32.0 ng/m³ for the supervisor to 131.1 ng/m³ during manual separation of waste. High concentrations of microorganisms were found in all facilities. The highest levels for both total fungi and bacteria (≥ 10⁶ cfu/m³) were recorded in the dumping pit at the resource-recovery plant and in the dumping pit at one of the waste-transfer plants. It is concluded that high levels of exposures to microorganisms, and to a lesser extent organic dusts and endotoxins, are likely to occur in many processes and activities in the waste-transfer and -processing industry, and that the possibility of health effects due to these exposures cannot be excluded.     

Changes in metal speciation and pH in olive processing waste and sulphur-treated contaminated soil

Degradation of organic matter from olive mill waste and changes in the heavy metal fractionation of a metal-contaminated calcareous soil were studied in a laboratory experiment, in which the olive mill waste was mixed with the soil and then incubated under aerobic conditions. The soil was calcareous (15% CaCO₃) with high Zn and Pb concentrations (2058 and 2947 mg kg⁻¹, respectively). The organic amendment was applied at a rate equivalent to 20 g kg⁻¹ soil, and unamended soil was run as a control. To discern if changes in metal solubility were due to the acidic character of the waste, elemental sulphur was applied to soil as a non-organic acidifying material. The S⁰ rates used were 3.14, 4.71 and 6.28 g kg⁻¹. The mineralisation of total organic-C (TOC) from the waste reached 14.8% of the original TOC concentration after 56 days of incubation. The CO₂–C produced from S⁰-treated soils showed the carbonate destruction by the H₂SO₄ formed through S⁰ oxidation. The organic waste increased EDTA-extractable Zn and Pb concentrations and CaCl₂-extractable Mn levels in soil after two days of incubation. The changes in metal availability with time indicated that the oxidation of phenols from the waste reduced Mn (IV) oxides, releasing Zn and Pb associated with this mineral phase. Organic waste addition did not decrease soil pH; the acidifying effect of S⁰ did not change metal fractionation in the soil.     

Faecal contamination of a tropical river in Nigeria and possible health risks

Information on the hygienic status of surface water is a major public health priority in tropical developing countries. The incidence and occurrence of indicator organisms and pathogenic Salmonellae were studied in a tropical river, the Kaduna, Nigeria, affected by urban waste‐water discharges mainly through open surface drains. The results indicate gross faecal contamination of both the urban waste‐water discharges and the receiving river. By using FC:FS ratios to determine the faecal pollution origin, it was evident that both human and animal sources pollute the river. This signifies that both sources of pollution should be considered in setting bacteriological standards for the waste‐water‐receiving surface water. Klebsiella and Escherichia spp. had similar frequencies of occurrence in the river. The urban effluent receiving river also carried Klebsiella pneumonia, Escherichia coli and pathogenic Salmonella spp. It was concluded that the use of urban waste‐water discharges and the receiving river for irrigation, recreation and water supply poses health risks to the public.     

实验室废水处理初探

实验室废水的危害性很大,然而关于如何解决这个问题的研究文献却很少。许多实验室废水的处理方法极其简单,甚至不加任何处理就排入下水道。通过对实验室废水进行调研,对其特性进行了总结,探讨了处理实验室废水的无害而易于操作的各种方法,并提出了综合处理实验室废水的方法。     

Toxicity of the micropollutants Bisphenol A,Ciprofloxacin, Metoprolol and Sulfamethoxazole in water samples before and after the oxidative treatment

The amount of organic micropollutants detected in surface waters increases steadily. Common waste water treatment plants are not built to remove these substances. Thus there is a need for new technologies. A promising technology is the use of advanced oxidation processes through which organic micropollutants can be removed from waste water. However, the formation of oxidation by-products is likely and needs to be investigated since the by-products not only differ from their parent compounds in regard to their chemical and physical properties but they can also differ in toxicity. Therefore this study was designed to combine chemical and toxicological analyses of the advanced oxidation (O₃ [5 mg/L] or UV/H₂O₂ [Hg-LP lamp; 15 W; 1 g/L H₂O₂]) of waste water treatment plant effluents and pure water. Effluent samples from conventional activated sludge waste water treatment (mechanical treatment, activated sludge basin, and primary as well as secondary treatment steps) and high-purity deionized water (pure water) were spiked with Bisphenol A, Ciprofloxacin, Metoprolol or Sulfamethoxazole and treated with O₃ or UV/H₂O₂. For the toxicological analyses mammalian cells (CHO-9, T47D) were exposed to the water samples for 24 h and were tested for cytotoxicity (MTT Test), genotoxicity (Alkaline Comet Assay) and estrogenicity (ER Calux^®). The results indicate that the oxidative treatment (O₃ or UV/H₂O₂) of Bisphenol A, Metoprolol, Sulfamethoxazole or Ciprofloxacin in waste water did not result in toxic oxidation by-products, whereas the UV/H₂O₂ treatment of Bisphenol A and Ciprofloxacin in pure water resulted in by-products with cytotoxic but no estrogenic effects after 60 min.     

石油化工废水及其污染地下水的致突变性研究

采用ＸＡＤ－２树脂吸附富集法应用Ａｍｅｓ试验对石油化工废水及其污染地下深井水中非挥发性混合有机污染物的致突变性进行了检测研究。结果表明，废水及其污染地下深井水对ＴＡ９８均有较强的致突变作用，不加Ｓ９时突变性更强。由此可见，石油化工废水排放区的地下深井水已受到污染     

密封垃圾车接污装置的设计与研究

在垃圾收运过程中，垃圾污水沿途洒漏问题不容忽视。通过对大连市 密封垃圾车接污染置设计原理及使用功能的论述，阐明了接污染置的研究在实际垃圾收运经当中所起到的重要作用。     

福建农村垃圾和污水治理的现状与对策

目的 掌握福建省农村垃圾、污水综合治理现状,为各级政府对农村环境卫生决策提供科学依据.方法 于2006年9-12月,调查福建省农村21个县(市、区)的215个行政村,同时每村抽取10户进行垃圾收集与污水排放等情况的调查.结果 被调查村垃圾产量达40 837.4 t/月,生活性垃圾占32.2%,生产性垃圾占67.8%0其中,生活性垃圾随意丢弃与收集堆放的占23.7%,无害化处理(焚烧、高温堆肥、直接再利用)的占8.5%;生产性垃圾随意丢弃与收集堆放的占30.7%,无害化处理(焚烧、高温堆肥、直接再利用)的占37.1%.被调查村每月共产生污水948 195 t,其中,生活性污水占57.5%,生产性污水占42.5%.其中,生活性污水的处理率仅为0.6%,生产性污水的处理率为33.0%.结论 农村公共卫生设施配套建设滞后,垃圾和污水无害化处理率低,随意丢弃、任意堆放(排放)垃圾现象普遍存在,农村环境卫生问题亟待改善.

Abstract：

Objective To understand the current status of overall management and treatment of garbage and waste water in rural areas of Fujian, and to provide scientific evidence for governments at all levels to make policies in rural sanitation. Methods From September to December,2006,215 villages in 21 counties in Fujian rural areas were selected,and 10 families were sampled and investigated for garbage collection and waste water treatment from each village. Results In the investigated villages,the production of garbage amounted to 40 837.4 tons per month; and domestic and productive garbage accounted for 32.2% and 67.8% of the total,respectively. Among the domestic garbage,23.7% was randomly discharged or stacked,and only 8.5% went through harmless treatment (incineration,composting under high temperature or direct reuse). However,30.7% productive garbage was randomly discharged or stacked,and 37.1% went through harmless treatment. Every month,948 195 tons of waste water was produced in the investigated villages;57.5% of them were domestic and 42.5% were productive. Only 0.6% of the domestic waste water and 33.0% of the productive waste water were treated. Conclusion The rural public health infrastructure building is far lagged, with low rate of harmless treatment of garbage and waste water. Random littering and piling (discharging) garbage are common phenomena in rural areas. Thus,it is urgent to improve rural sanitation development.     

Airborne bacteria and fungi associated with waste-handling work

Abstract

Background: Municipal workers handling household waste are potentially exposed to a variety of toxic and pathogenic substances, in particular airborne bacteria, gram-negative bacteria (GNB), and fungi. However, relatively little is known about the conditions under which exposure is facilitated.

Methods: This study assessed levels of airborne bacteria, GNB, and fungi, and examined these in relation to the type of waste-handling activity (collection, transfer, transport, and sorting at the waste pre-processing plant), as well as a variety of other environmental and occupational factors. Airborne microorganisms were sampled using an Andersen single-stage sampler equipped with agar plates containing the appropriate nutritional medium and then cultured to determine airborne levels. Samples were taken during collection, transfer, transport, and sorting of household waste. Multiple regression analysis was used to identify environmental and occupational factors that significantly affect airborne microorganism levels during waste-handling activities.

Results: The “type of waste-handling activity” was the only factor that significantly affected airborne levels of bacteria and GNB, accounting for 38% (P?=?0·029) and 50% (P?=?0·0002) of the variation observed in bacteria and GNB levels, respectively. In terms of fungi, the type of waste-handling activity (R²?=?0·76) and whether collection had also occurred on the day prior to sampling (P<0·0001, R²?=?0·78) explained most of the observed variation. Given that the type of waste-handling activity was significantly correlated with levels of bacteria, GNB, and fungi, we suggest that various engineering, administrative, and regulatory measures should be considered to reduce the occupational exposure to airborne microorganisms in the waste-handling industry.     

二氧化氯发生器在医疗污水处理中的应用

医疗单位排放的污水中，含有大量的病原微生物，被调查的25家医疗单位中，检出致病菌的10家，检出率为40％，因此，污水排放能否达到国家标准，选用一种的污水处理设备至关重要。高效复合二氧化氯发生器中一种消毒效果好又经济实用的污水处理设备。     

城市生活垃圾焚烧前堆酵脱水研究进展

分析了垃圾含水率及其与低位热值的关系,依据低位热值对垃圾焚烧工艺的影响,概述了垃圾焚烧前堆酵脱水的机理、研究现状,探讨了控制温度和接种微生物在加速堆酵脱水中应用的可行性,并对今后该领域的研究重点提出建议。     

北京市春季生活垃圾组成在物流系统中的变化分析

在北京市生活垃圾的物流流程的2个流向中,按照流向选取8个功能区、1个垃圾楼、1个转运站、1个处理处置场(堆肥厂、填埋场)的垃圾作为垃圾物流流程分析的取样点,测定垃圾的组分,以分析垃圾的组成、水分和密度在物流系统中的变化.     

炼油污水挥发物对作业工人脂质过氧化反应的影响

目的 探讨低浓度炼油污水作业对人体氧化和过氧化反应的影响。方法 检测73例污水处理作业工人和129例健康对照血清丙二醛（MDA）含量和血清超氧化物歧化酶（SOD）、全血谷胱甘肽过氧化物醇（GSH－Px)和过氧化氢酶（CAT）活力。结果 污水处理作业工人血清SOD和全血GSH－Px活力与对照组相比,差异具有显著性（P＜0．01）,CAT的差异不具有显著性。中工龄组（5－20年）GSH－Px活力明显高于对照组,而高工龄组（＞20年）差异不具有显著性。接触组SOD活力仅低工龄组（＜5年）较对照组高（P＜0．05）。结论 低浓度长期接触炼油污水挥发物,体内的脂质过氧化反应和抗氧化机制均处于亢奋状态,后者可能是机体的一种防御机制。     

Resources,Barriers, and Tradeoffs: A Mixed Methods Analysis of School Pre-Consumer Food Waste

BackgroundFood waste is a global problem. School food waste before the point of purchase, pre-consumer waste, has been little studied.ObjectiveOur aim was to elicit a comprehensive assessment and understanding of pre-consumer food waste amounts, behaviors, policies, and attitudes.DesignThis study used mixed methods, featuring a convergent parallel design using key respondent interviews (n=20) and 80 hours of structured kitchen observations, including food waste measurement.Participants/settingSchool and district kitchens (n=14) using stratified random sampling to ensure school level and kitchen type reflected the population of three Colorado school districts in 2016-2017. Kitchen managers, district-level nutrition services directors, and sustainability staff were interviewed.Statistical analyses performedMean food waste volumes and percentages were calculated. Linear regressions were used to determine the relationship between school kitchen characteristics and food waste volumes. Interviews were coded to identify common themes.ResultsTrim waste and overproduction contributed the most to overall pre-consumer food waste; substandard foods and overproduction were the most common reasons for edible waste. Several competing priorities conflicted with schools’ and districts’ waste reduction efforts: food safety, promoting diet quality, food choice, and customer satisfaction. Batch cooking, production record use, shallow salad bar pans, and other inventory management techniques facilitated waste reduction. Staffing, space, and time constraints made it more difficult to implement these strategies. Increased food choice options were positively associated with pre-consumer waste volume (β=49.5, P=0.04), and this relationship remained significant once regression models adjusted for district, salad bar use, and new menu items (β=70.3, P=0.05).ConclusionsSchool nutrition programs are complex, and a systems approach is warranted to reduce overall waste in the context of existing food safety and nutrition policies. More research is needed to elucidate the impact of food choice on overall food waste of the school meal system.