Residential Solid Waste Research Articles

Comparação da reação de imunofluorescência indireta e do teste de aglutinação modificado na detecção de anticorpos anti-Toxoplasma gondii em ratos

The toxoplasmosis is a zoonosis caused by Toxoplasma gondii and affects a lot of species of carnivores and omnivores, including the human. The rodents are important in the transmition cycle because they act as an infection font to felines, the definitive host of this protozoan. The objective of this work was to evaluate the Modified Agglutination Test (MAT) for the serologic diagnosis of toxoplasmosis in rats, comparing with the Indirect Fluorescent Antibody Test (IFAT), which has been considered the golden standard in animal toxoplasmosis diagnosis. Kappa test was used for comparing the serologic tests (IFAT and MAT) and for determination of cutoff appropriate to MAT in this animal species. 182 rats were caught on local recycling of solid waste and solid residue storage in Londrina city, Paraná. Out of the 182 rats, nine (4.94%) were positive to IFAT at a dilution of 1:16, and 17 (9.34%) and five (2.75%) were reactive to MAT in dilutions 1:25 and 1:50, respectively. The comparison of results between the techniques presented kappa coefficients of 0.26 and 0.55, respectively at 1:25 and 1:50 dilutions of MAT. It can be concluded that the dilution 1:50 is the most suitable to be used as cutoff for detecting T. gondii antibodies in rats using MAT, because agreed with IFAT.

Evaluation of solid residues removed from a mangrove swamp in the São Vicente Estuary, SP, Brazil

Mangrove swamps are found in estuaries along the coastal plains of tropical regions and have be subjected to heavy occupation and use pressure due to their privileged locations and abundance of biological resources. The present work evaluated the ecological characteristics and solid wastes accumulated in eight areas along the Santos – São Vicente Estuary Complex. The superficially deposited residues at each sampling site were collected and subsequently washed, drained, counted, weighed and separated into classes according to their composition and predominant use. The predominant litter type in terms of density was plastic (62.81%) and, by weight, wood (55.53%). The greatest deposition of residues was associated with areas that were less inclined and that had low plant density levels, indicating that the presence of obstacles was not critical for retaining floating residues in mangrove areas. The presence of the most frequently encountered types of solid waste residues could be explained by local activities.

Influence of Handling Practices on Material Recovery from Residential Solid Waste

Material recovery from municipal solid waste (MSW) is becoming widely adopted in several developing countries. Residential solid waste is one of the most important components of MSW and the handling practices of the MSW by the generators have a major impact on the quality and quantity of the materials for recovery. This article analyzes the generation and composition of residential solid waste and the handling practices by users in three municipalities in Colombia that have a solid waste management plant (SWMP). The findings show that, although there are significant amounts of useful materials, their handling of the materials as “garbage”, the low recognition of recovery work, and the inadequate storage and source management practices, affect material recovery and the operation of SWMPs. These results may be taken as a reference for this type of municipality, because the solid waste management system and the type of operation of the SWMPs analyzed is similar to all of the SWMPs in the country as well as in other countries in the region.

Effect of liquid-to-solid ratio on semi-solid Fenton process in hazardous solid waste detoxication

The liquid-to-solid ratio (L/S) of semi-solid Fenton process (SSFP) designated for hazardous solid waste detoxication was investigated. The removal and minimization effects of o-nitroaniline (ONA) in simulate solid waste residue (SSWR) from organic arsenic industry was evaluated by total organic carbon (TOC) and ONA removal efficiency, respectively. Initially, Box–Behnken design (BBD) and response surface methodology (RSM) were used to optimize the key factors of SSFP. Results showed that the removal rates of TOC and ONA decreased as L/S increased. Subsequently, four target initial ONA concentrations including 100 mg kg −1, 1 g kg −1, 10 g kg −1, and 100 g kg −1 on a dry basis were evaluated for the effect of L/S. A significant cubic empirical model between the initial ONA concentration and L/S was successfully developed to predict the optimal L/S for given initial ONA concentration for SSFP. Moreover, an optimized operation strategy of multi-SSFP for different cases was determined based on the residual target pollutant concentration and the corresponding environmental conditions. It showed that the total L/S of multi-SSFP in all tested scenarios was no greater than 3.8, which is lower than the conventional slurry systems (L/S ⩾ 5). The multi-SSFP is environment-friendly when it used for detoxication of hazardous solid waste contaminated by ONA and provides a potential method for the detoxication of hazardous solid waste contaminated by organics.

Local quantification and characterisation represents a basic tool for integrated residential solid waste management

A sampling and characterisation plan for residential solid waste (SW) produced in the city of Cali in Colombia was developed between January and September 2006; this required designing an undisclosed strategy in the country and the results showed the need for an adjustment to the current SW Colombian classification scheme. The available sampling frame made a two-stage sampling plan necessary, block side (BS) being the first stage and household BS the second. A 0.39 kg/(person-day) solid waste per-capita production (PCP) was found, which increased with socioeconomic status. Food waste was produced most, a large part consisting of cooked food. Waste from personal hygiene items was a third category, although this is not currently a category which is included in Colombian Technical Standard –RAS 2000. Although characterisation techniques are used worldwide, the results showed the relevance of available sampling frame-based local characterisation, using local data for sampling methods and associated sample size selection.

Molecular characterization and glomalin production of arbuscular mycorrhizal fungi colonizing a heavy metal polluted ash disposal island, downtown Venice

In this work the arbuscular mycorrhizal (AM) fungal communities colonizing a polluted ash dump island, downtown Venice, were studied by using a multimodal approach. The island, Sacca San Biagio, was covered with a thick layer of municipal solid waste residues produced by an incinerator operating from 1973, to 1984. Such residues contained high levels of heavy metals (Cu, Pb and Zn). We characterized the AMF communities present in soils on Sacca San Biagio island by using molecular methods. Nine AM fungal sequence types were detected in the roots of three plant species, representative of the dominant flora, by using partial SSU ribosomal RNA genes. The most abundant sequence types corresponded to Glomus intraradices/ Glomus fasciculatum, and to Glo18, a sequence detected so far only in planta. Two sequences were new to science. Glomalin-related soil protein (GRSP), extracted from rhizosphere soil of dominant plant species, ranged from 1.6 to 2.3 mg g −1. The occurrence of an active AM fungal community able to live in such harsh environment was evinced by the correlation between mycorrhizal colonization and GRSP content.

Decentralized Energy from Waste Systems

In the last five years or so, biofuels have been given notable consideration worldwide as an alternative to fossil fuels, due to their potential to reduce greenhouse gas emissions by partial replacement of oil as a transport fuel. The production of biofuels using a sustainable approach, should consider local production of biofuels, obtained from local feedstocks and adapted to the socio-economical and environmental characteristics of the particular region where they are developed. Thus, decentralized energy from waste systems will exploit local biomass to optimize their production and consumption. Waste streams such as agricultural and wood residues, municipal solid waste, vegetable oils, and algae residues can all be integrated in energy from waste systems. An integral optimization of decentralized energy from waste systems should not be based on the optimization of each single process, but the overall optimization of the whole process. This is by obtaining optimal energy and environmental benefits, as well as collateral beneficial co-products such as soil fertilizers which will result in a higher food crop production and carbon dioxide fixation which will abate climate change.

Optimization and characterization of a new lipopeptide biosurfactant produced by marine Brevibacterium aureum MSA13 in solid state culture

The biosurfactant production of a marine actinobacterium Brevibacterium aureum MSA13 was optimized using industrial and agro-industrial solid waste residues as substrates in solid state culture (SSC). Based on the optimization experiments, the biosurfactant production by MSA13 was increased to threefold over the original isolate under SSC conditions with pre-treated molasses as substrate and olive oil, acrylamide, FeCl 3 and inoculums size as critical control factors. The strain B. aureum MSA13 produced a new lipopeptide biosurfactant with a hydrophobic moiety of octadecanoic acid methyl ester and a peptide part predicted as a short sequence of four amino acids including pro-leu-gly-gly. The biosurfactant produced by the marine actinobacterium MSA13 can be used for the microbially enhanced oil recovery processes in the marine environments.

A review of residential solid waste management in the occupied Palestinian Territory: a window for improvement?

Solid waste is considered an urgent environmental health issue in the Palestinian Territory. The aim of this paper was to analyse the current status of residential solid waste (RSW) management in the Palestinian Territory, with the objective of identifying windows for improvement. The study is based on a national household sample survey in the Palestinian Territory, which was conducted by the Palestinian Central Bureau of Statistics (PCBS). The results of this study revealed various interesting trends. For example, while about 90% of households in the Palestinian Territory receive solid waste collection service, about 50% of the households receive this service three times per week or less, leaving a chance for waste pile-up and litter generation. Organic waste (including food waste) was found to account for more than 90% of RSW, providing an opportunity for waste utilization through composting or biogas generation. Additional efforts are required, and some were suggested in this paper, in order to improve the current situation of Palestinian residential solid waste management.

Solid Waste Crisis in Nigeria – A Case Study of the Constraint to Effective Private Sector Participation (PSP) on Solid Waste Management in Lagos Metropolis

Among the multitude of problems existing in the fast urbanizing towns and cities in Nigeria, Solid waste appears to be the most prominent in recent years. Solid waste is seen in huge heaps on any piece of unused land, around buildings and in the open market places. Living with solid waste littered around appears to be an acceptable way of life among the people in most cities in Nigeria in recent years. The work reported in this paper involves a preliminary study of residential solid waste management in the Lagos metropolis in Nigeria. A site-specific study was carried out to estimate the quantity of residential solid waste generation, disposal and management in the metropolis. Structured questionnaires were applied to collect primary information such as size of households, income, Educational level etc. from households. The results obtained indicated that the problem of insufficient available data, insufficient funding, poor understanding of solid waste management by the PSP operators and poor publics attitude are the causes of solid waste crisis in Nigeria. Proposal on strategies for the improvement of the effectiveness of the PSP operators in Lagos metropolis has been presented.

Sensorized waste collection container for content estimation and collection optimization

The concurrent effects of a fast national growth rate, of a large and dense residential area and a pressing demand for urban environmental protection create a challenging framework for waste management in Pudong New Area, Shanghai. The complexity of context and procedures is indeed a primary concern of local municipal authorities due to problems related to the collection, transportation and processing of residential solid waste. In order to design and implement a suitable urban solid waste system, the first task is to forecast the quantity and variance of solid waste as it relates to residential population, consumer index, season, etc. The system here discussed addresses exactly these issues, by means of an intelligent, sensorized container. The container has been prepared and tested in the Pudong New Area, Shanghai.

Increasing significance of advanced physical/chemical processes in the development and application of sustainable wastewater treatment systems

The awareness of the problem of the scarcity of water of high quality has strongly changed the approach of wastewater treatment. Currently, there is an increasing need for the beneficial reuse of treated wastewater and to recover valuable products and energy from the wastewater. Because microbiological treatment methods are, only to a limited part, able to satisfy these needs, the role and significance of physical/chemical processes in wastewater treatment are gaining more and more interest. The specific future role and aim of the various physical/chemical treatment processes can be categorized in five groups: improvement of the performance of microbiological treatment processes, achievement of the high quality required for reuse of the effluent, recovery of valuable components and energy from the wastewater for beneficial reuse, desalination of brackish water and seawater, and treatment of concentrated liquid or solid waste residues produced in a wastewater treatment process. Development of more environmentally sustainable wastewater treatment chains in which physical/chemical processes play a crucial role, also requires application of process control and modeling strategies. This is briefly introduced by the elaboration of treatment scenarios for three specific wastewaters.

Provision of Residential Solid Waste Management Service in Rural China

AbstractDrawing on a dataset covering a large number of randomly sampled villages across China, the present paper examines the issue of residential solid waste management service provision in rural China. Using a logistic model we evaluate the impacts of different factors on service provision at the village level with regard to residential solid waste disposal. These factors include the environmental pressures caused by residential solid waste generation, the financial capacity of the Villagers' Committee, village elections and the individual characteristics of village heads. We find that living density, village per capita income, the ratio of irrigated land, and the per capita profit submitted by village enterprises to the Villagers' Committee all have positive impacts on service provision. Moreover, village heads who are popularly elected by villagers are more likely to provide services that satisfy voters' demands.

Mathematical modeling to predict residential solid waste generation

One of the challenges faced by waste management authorities is determining the amount of waste generated by households in order to establish waste management systems, as well as trying to charge rates compatible with the principle applied worldwide, and design a fair payment system for households according to the amount of residential solid waste (RSW) they generate. The goal of this research work was to establish mathematical models that correlate the generation of RSW per capita to the following variables: education, income per household, and number of residents. This work was based on data from a study on generation, quantification and composition of residential waste in a Mexican city in three stages. In order to define prediction models, five variables were identified and included in the model. For each waste sampling stage a different mathematical model was developed, in order to find the model that showed the best linear relation to predict residential solid waste generation. Later on, models to explore the combination of included variables and select those which showed a higher R(2) were established. The tests applied were normality, multicolinearity and heteroskedasticity. Another model, formulated with four variables, was generated and the Durban-Watson test was applied to it. Finally, a general mathematical model is proposed to predict residential waste generation, which accounts for 51% of the total.

Assessing the effectiveness of voluntary solid waste reduction policies: Methodology and a Flemish case study

The purpose of this paper is to illustrate the use of statistical techniques to evaluate the effectiveness of voluntary policy instruments for waste management. The voluntary character of these instruments implies that latent characteristics, unobserved by the analyst, might influence the subscription decision and might lead to biased estimates of the effectiveness of the policy instrument if standard techniques are used. We propose an extension of the difference-in-differences (DiD) estimator to evaluate the effectiveness of voluntary policy instruments, which is termed the dynamic difference-in-differences (or DDD) estimator. We illustrate the technique by estimating the effectiveness of voluntary cooperation agreements between the Flemish environmental administration and individual municipalities aimed at curbing residential solid waste. Using a dataset covering all 308 Flemish municipalities for the period 2000-2005, our results indicate that municipalities subscribing to the agreement accomplished less reduction of their waste levels compared to what could be expected on the basis of their own performance prior to subscription and the performance of the non-subscribers. This result might be explained by the rising marginal cost of extra residential solid waste reduction policies. In addition, there are indications that subscribing municipalities refrain from additional reduction efforts once the target waste level of the program is achieved. The more complicated DDD methodology is shown to generate additional insight over the ordinary DiD analysis.

Leaching characteristics of PCDDs/DFs and dioxin-like PCBs from landfills containing municipal solid waste and incineration residues

To investigate the leaching characteristic of persistent organic pollutants (POPs), such as non-ortho and mono-ortho substituted chlorobiphebyls (dioxin-like PCBs), polychlorinated dibenzo- p-dioxins and dibenzofurans (PCDDs/DFs), in leachate from municipal solid waste (MSW) landfill sites containing incineration residues, raw leachate samples were collected twice from 12 selected MSW landfill sites. The samples were divided into their liquid and solid phases using GF/B (pore size 1.0 μm), and the concentrations of POPs then determined. The concentrations of PCDDs/DFs ranged from 0.65 to 5.88 pg-TEQ/l (average 2.86 pg-TEQ/l), and those of dioxin-like PCBs from 0.05 to 0.32 pg-TEQ/l (average 0.18 pg-TEQ/l). The major congeners of leached PCDDs/DFs and dioxin-like PCBs in liquid and solid phases were OCDD (about 60%), 2,3′,4,4′,5-PeCBs (about 30%), and 2,3,4,4′,5-PeCBs (about 54%). The relationship between landfill age and the leaching concentration of PCDDs/DFs, and effects of dissolved organic carbon (DOC) on the leaching of PCDDs/DFs are also discussed. Finally, a leaching prediction model of PCDDs/DFs from MSW landfills has been suggested using parameters, such as hydrophobic neutral organic carbons, total dissolved solid, and the ratio of non-biodegradable wastes in landfill sites.

The Landfill Area Quality (LAQ) Classification Approach and Its Application in Isparta, Turkey

The amount of residential and industrial solid waste, and the need for landfill sites, is ever growing due to increases in population and industrial production. Landfilling is a widely used method for environmentally safe disposal of solid waste, and the selection of the most suitable landfill site is a very crucial decision. In this study, a new site evaluation method to determine suitable landfill sites, called Landfill Area Quality (LAQ), is introduced. This method is applied in two stages. First, several potential landfill sites, which are within legally permissible areas, are chosen by a general consideration of the relevant site properties. Then, the characteristics of these chosen sites are placed within three-dimensional evaluation spaces. These evaluative dimensions are (1) site suitability, (2) location factors, and (3) public acceptability, and each is defined by a combination of different criteria. The result of this re-evaluation, which provides valuable information to planning engineers and decision makers about the available sites, is reported to decision makers for the final selection. A detailed case study was carried out as part of a residential solid waste disposal project for the city of Isparta in Turkey, (population 150,000), and was very useful to planners.

Minimization of the environmental impact of chrome tanning: A new process with high chrome exhaustion

In all tanning technology operations wastes are generated. These reach the environment as residual waters, solid and liquid waste as well as atmospheric emissions and odours. This study tests an alternative method to the traditional tanning method at an industrial level. The new method is based on tanning without float and by significantly increasing the temperature at the end of the tanning process. The properties of the leathers obtained using the two methods have been compared and the results indicate that those leathers have similar physical, chemical, and organoleptic properties. However, the differences existing from the environmental point of view are significant. It is not necessary to use clean water for this tanning. Moreover, there is a 75% reduction of the residual float, a 91% reduction of the chrome discharged, and a 94% reduction of the chlorides discharged. A financial assessment was carried out to demonstrate that the newly proposed system is 32% more economic than the traditional one.

Leachate and gaseous emissions from initial phases of landfilling mechanically and mechanically–biologically treated municipal solid waste residuals

In this study, the behaviour, and leachate and gaseous emissions during the initial phases of landfilling mechanically (M) and mechanically–biologically (MB) treated municipal solid waste residuals in northern climatic conditions was compared using two landfill lysimeters (112 m 3). The results demonstrate that the strong acid phase of M residuals degradation lasts at least 2 years, while in the MB residuals the acid phase lasts only a few months. The SCOD and NH 4–N concentrations varied 20–100 g/l and 600–1800 mg/l in M leachate and 1–4 g/l and 100–400 mg/l in MB leachate, respectively. The leaching of SCOD was approximately 40-fold (24.2 and 0.6 kg/t TS) and leaching of NH 4–N approximately 5-fold (356 and 60 g/t TS) from the M than MB residuals; thus the effect of biological stabilisation was more marked on the leaching of SCOD than of NH 4–N. Moreover gas (methane, carbon dioxide and nitrous oxide) emissions were several-fold higher from the M than MB residuals.

Assessing the Effectiveness of Voluntary Solid Waste Reduction Policies: Methodology and a Flemish Case Study

The purpose of this paper is to illustrate the use of statistical techniques to evaluate the effectiveness of voluntary policy instruments for waste management. The voluntary character of these instruments implies that latent characteristics, unobserved by the analyst, might influence the participation decision and might lead to biased estimates of the effectiveness of the policy instrument if standard techniques are used. We propose an extension of the Difference-in-Differences estimator to evaluate the effectiveness of voluntary policy instruments. We illustrate the technique by estimating the effectiveness of voluntary cooperation agreements between the Flemish environmental administration and individual municipalities. We focus on agreements which aim at curbing residential solid waste. Using a dataset covering all 308 Flemish municipalities for the period 2000-2005, our results indicate that municipalities subscribing to the agreement reduced their waste level by less than what could be expected on the basis of their own performance prior to subscription and the performance of the non-subscribers. This result might be explained by rising marginal cost of extra residential solid waste reduction policies. In addition, there are indications that subscribing municipalities refrain from additional reduction efforts once the target waste level of the program is achieved.