Relation between substrate feeding pattern and development of filamentous bacteria in activated sludge processes: Part III. applications with industrial waste waters

Summary Laboratory scale activated sludge systems were operated under regimes of continuous or intermittent feeding of the waste water. Industrial waste waters from breweries, a dairy plant and a petro-chemical plant were investigated. The systems were started up with sludge from a municipal waste water plant or more often with sludges obtained from the corresponding industrial waste water treatment plants. It was found that intermittently fed systems produced sludges with better settleability characteristics than systems that were continuously supplemented with waste water. Our previous hypothesis that in intermittent systems floc forming bacteria become dominant as a result of higher substrate uptake rates was confirmed and may thus be extended to waste waters containing readily available substrates such as carbohydrates (brewery-and dairy waste water) or acids (petro-chemical waste water). Supplementation of brewery waste water with urea had a negative influence on sludge settleability, especially in continuously operated systems.     

Using tea waste as a new casing material in mushroom (Agaricus bisporus (L.) Sing.) cultivation

In this study, the possibility of using tea production waste as a new casing material in mushroom (Agaricus bisporus) cultivation was investigated. Some physical and chemical characteristics of tea waste, fermented tea waste and a mixture of tea waste with peat were compared with that of peat casing, as were their effects on yield. The highest yield was obtained from peat casing. Using tea production waste alone as a casing was not acceptable for assured yield when it was compared with peat. But, a mixture of tea production waste with peat in 1:1 (v:v) ratio increased the yield. There was no significant difference between the mushroom yields of tea production waste+peat and peat casing materials at the end of 30 and 40 days. High salt content, organic and inorganic compounds in casing materials caused reduction of yields. However, a high iron content in casing material gave a significant positive correlation with total yield at 40 days.     

Efficient use of shrimp waste: present and future trends

The production of shrimp waste from shrimp processing industries has undergone a dramatic increase in recent years. Continued production of this biomaterial without corresponding development of utilizing technology has resulted in waste collection, disposal, and pollution problems. Currently used chemical process releases toxic chemicals such as HCl, acetic acid, and NaOH into aquatic ecosystem as byproducts which will spoil the aquatic flora and fauna. Environmental protection regulations have become stricter. Now, there is a need to treat and utilize the waste in most efficient manner. The shrimp waste contains several bioactive compounds such as chitin, pigments, amino acids, and fatty acids. These bioactive compounds have a wide range of applications including medical, therapies, cosmetics, paper, pulp and textile industries, biotechnology, and food applications. This current review article present the utilization of shrimp waste as well as an alternative technology to replace hazardous chemical method that address the future trends in total utilization of shrimp waste for recovery of bioactive compounds.     

Life Cycle Inventory for Use of Waste Solvent as Fuel Substitute in the Cement Industry - A Multi-Input Allocation Model (11 pp)

Background The Swiss chemical industry produces large amounts of organic waste solvents. Some of these solvents cannot be recovered. A common option for the treatment of such organic waste solvents is the incineration in hazardous waste incinerators. Alternatively, the waste solvents can be used as fuel in cement production. On the one hand, solvent incineration in cement kilns saves fossil fuels such as coal and heavy fuel oil. On the other hand, fuel-bound emissions may change as well. These emission changes can either have a negative or a positive net ecological impact, depending on the chemical nature of the waste solvent used.Goal and Scope The aim of our work was to develop a multi-input allocation model, which allows one to calculate life cycle inventories for specific waste solvents. These LCIs can then be used in further applications, e.g. a comparison of different waste solvent treatment options. Results and Discussion A multi-input allocation model was developed that takes into account the physico-chemical properties of waste solvents such as elementary composition and net calorific value. The model is based on a set of equations and data on fuel mix, fuel composition as well as transfer coefficients for heavy metals. The model calculates “avoided inputs” and “changes in emissions” which arise from substituting fossil fuels with waste solvents. Life cycle inventories can be calculated for specific waste solvents if the elementary composition and the net calorific value are known. The application of the model is illustrated in a case study on four waste solvents. The results show that solvent incineration in cement kilns generally reduces the overall impact of clinker production because fossil fuels are replaced. A sensitivity analysis revealed that the model is especially sensitive to the fuel mix and coal properties, such as net calorific value as well as the content of nitrogen and carbon. The transfer coefficients are also uncertain, but this uncertainty is not relevant as the amount of heavy metal emitted into the atmosphere is small. Conclusions and Outlook The proposed model serves to calculate inventory data for the combustion of liquid alternative fuels such as waste solvents in cement kilns. Although our model represents Swiss cement production conditions, it can be applied to other countries by fitting the most sensitive parameters of fuel mix and coal properties. In case the technology used is very different to the Swiss situation, the transfer coefficients also need to be adapted.     

Cellulolytic activity in leachate during leach-bed anaerobic digestion of municipal solid waste

The degradation of municipal solid waste (MSW) under mesophilic conditions can be enhanced by exchanging leachate between fresh waste and stabilised waste. The optimum point in time when leachate from an anaerobically digesting waste bed can be used to initiate degradation of another waste bed might occur when the leachate of the digesting waste bed is highly active with cellulolytic and methanogenic bacteria. In this study, the cellulolytic activity of the leachate was measured using the cellulose-azure assay. As products of hydrolysis are soluble compounds, the rate of generation of these compounds was estimated based on a soluble chemical oxygen demand (SCOD) balance around the fresh waste bed. It was found that once the readily soluble material present in MSW was washed out there was very little generation of SCOD without the production of methane, indicating that flushing leachate from a stabilised waste bed resulted in a balanced inoculation of the fresh waste bed. With the onset of sustained methanogenesis, the rate of SCOD generation equalled the SCOD released from the digester as methane. The experimental findings also showed that cellulolytic activities of the leachate samples closely followed the trend of SCOD generation.     

Application of waste activated bleaching earth containing rapeseed oil on riboflavin production in the culture of Ashbya gossypii

Waste activated bleaching earth (ABE) that contained 40% rapeseed oil and was discharged by an oil refinery plant, was used for riboflavin production in a culture of Ashbya gossypii. When 125 g/L waste ABE that contained 50 g/L rapeseed oil was added into the culture, the riboflavin concentration was 1.12 g/L, which was almost 1.6-fold as high as that of pure rapeseed oil. However, in waste ABE concentration higher than 125 g/L, the produced riboflavin concentration decreased, which was due to the difficulty in mixing due to the presence of a high amount of solid material in the culture. The surface of the waste ABE was smooth without a hitch, because of being covered with rapeseed oil. However, after the culture, the surface of the waste ABE seemed like that of new one, and the oil content was nearly zero grams per liter. The waste ABE, oily clay, and its black color gradually fade and yellow little by little, and finally the waste ABE changed to yellow powder. Of the riboflavin produced during the culture, 70% was adsorbed in the oil free waste ABE. With diluted alkali solution, extraction only two times yielded 90% recovery of riboflavin adsorbed in the waste ABE. The waste ABE containing waste vegetable oil was suitable for raw material for production of the value-added useful bioproducts, which might be a good model for reuse of the waste resource.     

Anaerobic digestion of municipal solid waste and agricultural waste and the effect of co-digestion with dairy cow manure

Anaerobic digestion of dairy cow manure (CM), the organic fraction of municipal solid waste (OFMSW), and cotton gin waste (CGW) was investigated with a two-phase pilot-scale anaerobic digestion (AD) system. The OFMSW and CM were digested as single wastes and as combined wastes. The single waste digestion of CM resulted in 62m(3) methane/ton of CM on dry weight basis. The single waste digestion of OFMSW produced 37m(3) methane/ton of dry waste. Co-digestion of OFMSW and CM resulted in 172m(3) methane/ton of dry waste. Co-digestion of CGW and CM produced 87m(3) methane/ton of dry waste. Comparing the single waste digestions with co-digestion of combined wastes, it was shown that co-digestion resulted in higher methane gas yields. In addition, co-digestion of OFMSW and CM promotes synergistic effects resulting in higher mass conversion and lower weight and volume of digested residual.     

Estimation of Waste Battery Generation and Analysis of the Waste Battery Recycling System in China

China produces and consumes a large amount of batteries annually, which leads to many waste batteries needing to be recycled. The collection and recycling system of primary, alkaline secondary, and lithium‐ion secondary batteries in China is particularly poor, and waste battery recycling enterprises generally sustain economic losses if they solely use waste batteries as raw materials. Increasing the profits of waste battery recycling systems is a key problem that needs to be considered. This article quantitatively analyzes waste battery generation in China by using annual sales data and probable lifetime distribution of various batteries. The results show that the rapid growth of battery usage has led to an increased generation of waste batteries and the percentage of different types of waste batteries is changing over time. In 2013, the total quantity of all waste batteries in the medium lifetime scenario reached 570 kilotons, of which primary, alkaline secondary, and lithium‐ion secondary waste batteries accounted for approximately 36%, 28%, and 35%, respectively. Based on a real‐world case study of a typical domestic waste battery recycling enterprise in China, material flow analysis and cost‐benefit analysis were conducted to study the development of the recycling process of comingled waste batteries. Through scenario analysis, we conclude that increasing the use of waste batteries as raw materials and the recycling of other materials that are less valuable reduces the profits of the waste battery recycling enterprise. Higher profits can be achieved by adding the production of high value‐added downstream products and government support. At the same time, the essential role of the government in developing a waste battery recycling system was identified. Finally, relevant suggestions are made for improvements in both the government and enterprise sectors.     

Supporting environmentally sound decisions for waste management with LCT and LCA

Introduction  

The amount of waste generated in Europe and, beyond, by our production and consumption patterns is significant. A proper waste management is essential in order to reduce detrimental environmental impacts. For the European Union, the general principles of good waste management are outlined in the Waste Framework Directive (2008/98/EC). This directive establishes a five-step hierarchy of waste management starting with the preferred option of waste prevention followed by preparing waste for reuse, recycling and other recovery with disposal (such as landfill) as the last resort.     

Microbial valorization of underutilized and nonconventional waste streams

The growing burden of waste disposal coupled with natural resource scarcity has renewed interest in the remediation, valorization, and/or repurposing of waste. Traditional approaches such as composting, anaerobic digestion, use in fertilizers or animal feed, or incineration for energy production extract very little value out of these waste streams. In contrast, waste valorization into fuels and other biochemicals via microbial fermentation is an area of growing interest. In this review, we discuss microbial valorization of nonconventional, aqueous waste streams such as food processing effluents, wastewater streams, and other industrial wastes. We categorize these waste streams as carbohydrate-rich food wastes, lipid-rich wastes, and other industrial wastes. Recent advances in microbial valorization of these nonconventional waste streams are highlighted, along with a discussion of the specific challenges and opportunities associated with impurities, nitrogen content, toxicity, and low productivity.     

城市生活垃圾的微生物处理技术

城市生活垃圾量的日益增多严重威胁着城市的环境及人们的健康,垃圾处理成为现代社会面临的重要问题之一,因此城市生活垃圾处理技术对于城市的可持续发展起着非常重要的作用。微生物在自然界中种类繁多,在城市生活垃圾生物处理应用中占有重要地位。本文对微生物在城市生活垃圾的卫生填埋技术、生物反应器填埋技术、好氧堆肥技术、发酵降解技术及生物干燥器技术中的应用进行了综述,并对城市生活垃圾的综合处理提出建议,以期为城市生活垃圾的微生物处理技术的应用提供参考。     

Nest Etiquette—Where Ants Go When Nature Calls

Sanitary behaviour is an important, but seldom studied, aspect of social living. Social insects have developed several strategies for dealing with waste and faecal matter, including dumping waste outside the nest and forming specialised waste-storage chambers. In some cases waste material and faeces are put to use, either as a construction material or as a long-lasting signal, suggesting that faeces and waste may not always be dangerous. Here we examine a previously undescribed behaviour in ants – the formation of well-defined faecal patches. Lasius niger ants were housed in plaster nests and provided with coloured sucrose solution. After two months, 1–4 well defined dark patches, the colour of the sucrose solution, formed within each of the plaster nests. These patches never contained other waste material such as uneaten food items, or nestmate corpses. Such waste was collected in waste piles outside the nest. The coloured patches were thus distinct from previously described ‘kitchen middens’ in ants, and are best described as ‘toilets’. Why faeces is not removed with other waste materials is unclear. The presence of the toilets inside the nest suggests that they may not be an important source of pathogens, and may have a beneficial role.     

Waste Costing as a Catalyst in Pollution Prevention Investment Decisions

This article presents a case study in a Nigerian firm of how waste costing can be applied to pollution prevention (P2) investment decisions. This case is informed by the priority accorded to P2 as a preferred alternative to end‐of‐pipe pollution control. It demonstrates that even in the absence of effective regulations in a developing country, cost accounting can spur P2 decisions by management through the system of waste cost allocation. The case used standard cost data from the Wonder Beauty Care Company and applied the activity‐based costing (ABC) system to waste cost allocation using waste cost drivers, which yielded another genre of waste costs—waste‐induced overhead. Subsequently, the waste‐induced overhead was applied to P2 investment analysis. This analysis indicated that the P2 investment alternative that incorporates the waste‐induced overhead produced a preferred alternative choice. The case further revealed that managers’ knowledge of waste costs in a Nigerian firm may influence their P2 decisions. The case illustrates practically a possible dual advantage of an improved costing system for Nigerian firms—cost reduction and cleaner production.     

Bioconversion of poultry manure and vegetable waste mixes by Hermetia illucens (Diptera: Stratiomyidae)

Development time, survival and final nutrient content of Hermetia illucens L. larvae depends on the substrates in which they develop. Mixing different waste types together can increase the performance and survival of the larvae, as well as their waste reduction. The main objective of this study was to evaluate the effect of different ratios of mixed fruit and vegetable waste with poultry manure on larval development time, size, biomass production, survival, bioconversion and waste reduction. Freshly hatched neonates (90 mg; approx. 6000 individuals) were placed on 12 kg of a mixture of fruit and vegetable waste and fresh, unprocessed poultry manure and held at 28 ± 0.5°C. Inclusion of fruit and vegetable waste varied from 0% to 100% in 10% increments. Initial temperature of the substrate was also measured. The individual mass of larvae increased significantly as more fruit and vegetable waste was included, from less than 81.3 ± 6.6 mg on poultry manure only to an average size of 211.6 ± 6.0 mg at 100% fruit and vegetable waste. After approximately 60% inclusion of fruit and vegetable waste the performance and survival of the larvae increased significantly while development time was reduced. A combination of high fruit and vegetable waste and low initial temperatures resulted in lower development time overall. The mixing of wastes can be applied in industry to further the goals of waste reduction and biomass production while incorporating low-quality wastes like poultry manure.     

A survey of life cycle approaches in waste management

Background, aim, and scope  

Life-cycle thinking and life-cycle approaches are concepts that are getting increased attention worldwide and in particular in EU Policies related to sustainability. The European Commission is launching a number of activities to strengthen life-cycle thinking in policy and business. EU policies aim to decrease waste generation through new waste prevention initiatives, better use of resources and shift to more sustainable consumption patterns. The approach to waste management is based on three principles: waste prevention, recycling and reuse and improving the final disposal and monitoring. In particular, concerning the prevention and recycling of waste, the definition of a waste hierarchy should be the basis for the prioritisation of waste management options. The benefit of using Life Cycle Assessment (LCA) in analysing waste management systems is the provision of a comprehensive view of the processes and impacts involved. However, it is also clear that the studies will always be open for criticism as they are simplifications of reality. Moreover, in order to become the LCA, a leading tool within businesses and government to understand and manage risks or opportunities related to waste management and treatment technologies, there are methodological choices required and a number of aspects that still need to be worked out. It is therefore important to review open and grey literatures, EU guidelines, relevant environmental indicators and databases for the waste sector and data easily usable in waste policy decision-making, with an agreed approach and methodology based on life-cycle thinking. The following survey gathers and describes the existing guidelines and methodologies based on life-cycle thinking and applicable in waste policy decision-making.     

中国餐厨垃圾处理的现状、问题和对策

餐厨垃圾具有高水分、高盐分、高有机质含量、组分时空差异明显、危害性与资源性并存的特点。目前国内外常用的餐厨垃圾处理技术如焚烧、卫生填埋、生态饲料、厌氧消化、好氧堆肥和蚯蚓堆肥等,通常存在着资源化利用效率低、经济效益不够理想的缺陷。总结相关文献及报道,中国在餐厨垃圾资源化处理上存在"行政瓶颈"和"技术瓶颈"两大方面的问题:"行政瓶颈"的解决之道在于完善管理及处理体系,各级政府部门切实重视、加大投入,强力推进垃圾分类投放;而对于"技术瓶颈",除综合运用多种现有处理技术外,开发新技术提高餐厨垃圾的资源化循环利用程度,是关键所在。     

油页岩废渣场的生态恢复

油页岩开采带来一系列的生态与环境问题 ,但对油页岩废渣场进行生态恢复的历史还较短 ,也缺少系统专门的研究报道。国外对油页岩废渣的利用始于 2 0世纪 4 0年代 ,对废渣场生态恢复的研究始于 2 0世纪 6 0年代 ,均早于我国。由于废渣场的基质成分恶劣 ,缺乏一般的土壤结构 ,复垦难度大。一般有 3种常规的复垦方法 :不经处理直接栽种植物 ;常规的物理或化学处理后栽种植物 ;表土覆盖后再进行植被恢复。前 2种方法均难产生显著效果 ,第 3种见效较快 ,但工作量大。近年来 ,一些新技术 ,如生物降解、生物富集和生物强化技术等被发明并用来恢复油页岩废弃地 ,取得了较好的生态恢复与修复效果。我国从 1985年开始 ,在广东茂名进行油页岩废渣场的生态恢复工作 ,先后对面积达 1.4 km2 和 6 .7km2 的 2个大型废渣场 (南排土场和北排土场 )进行了治理 ,主要是采用生物修复技术中的植物修复来进行试验。南排土场经过 19a的复垦演替成了郁郁葱葱的森林 ;北排经过 5 a的实践也取得了很好的恢复效果 ,一些幼林初步形成。然而 ,当前北排土场恢复实践中出现了一些很值得关注的现象 ,如乔木树种矮化、分枝增多等 ,但这些问题还有待进一步研究解决。此外 ,还探讨了油页岩废渣场开展生态恢复的步骤与原则     

Growth of Pichia guilliermondii A9, an osmotolerant yeast, in waste brine generated from kimchi production

The possibility of culturing an osmotolerant yeast using waste brine from a kimchi factory as a substrate for the production of single cell protein was investigated. Pichia guilliermondii A9 was selected from 70 isolates of yeast demonstrating substantial growth in the waste brine. The growth of P. guilliermondii A9 in waste brine was not inhibited by NaCl concentrations of up to 10% (w/v). However, it was reduced drastically at concentrations greater than 12% (w/v). Approximately 90% of BOD was removed from the waste brine by culturing of P. guilliermondii A9 for 24 h. The maximum cell yield was 0.69 g of dry cells per liter, containing 40% of protein. When the waste brine was enriched with cabbage juice from waste cabbage, the final cell mass increased proportionally with the amount of added organic material. Salt stressed cells of P. guilliermondii A9 grown in waste brine are shown in scanning electron micrographs. In conclusion, the large amounts of waste brine generated from kimchi production could be used directly for the culture of the osmotolerant yeast P. guilliermondii A9.     

Dynamic Eco-Efficiency Projections for Construction and Demolition Waste Recycling Strategies at the City Level

In this article we have elaborated a consistent framework for the quantification and evaluation of eco‐efficiency for scenarios for waste treatment of construction and demolition (C&D) waste. Such waste systems will play an increasingly important role in the future, as there has been for many years, and still is, a significant net increase in stock in the built environment. Consequently, there is a need to discuss future waste management strategies, both in terms of growing waste volumes, stricter regulations, and sectorial recycling ambitions, as well as a trend for higher competition and a need for professional and optimized operations within the C&D waste industry. It is within this framework that we develop and analyze models that we believe will be meaningful to the actors in the C&D industry. Here we have outlined a way to quantify future C&D waste generation and have developed realistic scenarios for waste handling based on today's actual practices. We then demonstrate how each scenario is examined with respect to specific and aggregated cost and environmental impact from different end‐of‐life treatment alternatives for major C&D waste fractions. From these results, we have been able to suggest which fractions to prioritize, in order to minimize cost and total environmental impact, as the most eco‐efficient way to achieve an objective of overall system performance.     

荧光光谱分析法在地沟油鉴别中的应用研究

由于地沟油的成分含量复杂性和不定量性,导致了现有的单一检测方法不能同时满足快速和准确的辨认。荧光光谱具有高灵敏度和分辨率的特性,由此提出了一种利用荧光光谱快速检测食用油中是否掺有地沟油的新方法。将花生油分成7组,每组油所含的地沟油的比例不同,用220 nm到800 nm的激发和发射光检测各组样品油,收集其荧光数据后做归一化处理进行分析。在荧光实验中,特别是在365 nm和720 nm激发波长波段和434 nm发射波长波段,样品油的荧光强度与所含地沟油的体积分数大小明显成反比,当地沟油的体积分数大于5%时,荧光强度的衰减更为明显。结果证明了荧光光谱法检测地沟油的可行性,而且步骤更为简单。利用荧光光谱的非接触和高灵敏度的优势,能够更为简便地检测到加入了5%以上地沟油的花生油。