Showing papers on "Waste disposal published in 2010"
TL;DR: For the first time, a multi-variables optimization approach is described to determine the optimum operation parameters so as to enhance process performance and photooxidation efficiency in the photocatalytic water treatment process.
4,293 citations
TL;DR: In this paper, a glasshouse study of two agricultural soils with two biochars derived from the slow pyrolysis of papermill waste was assessed in a glass house study.
Abstract: The amendment of two agricultural soils with two biochars derived from the slow pyrolysis of papermill waste was assessed in a glasshouse study. Characterisation of both biochars revealed high surface area (115 m2 g−1) and zones of calcium mineral agglomeration. The biochars differed slightly in their liming values (33% and 29%), and carbon content (50% and 52%). Molar H/C ratios of 0.3 in the biochars suggested aromatic stability. At application rates of 10 t ha−1 in a ferrosol both biochars significantly increased pH, CEC, exchangeable Ca and total C, while in a calcarosol both biochars increased C while biochar 2 also increased exchangeable K. Biochars reduced Al availability (ca. 2 cmol (+) kg−1 to <0.1 cmol (+) kg−1) in the ferrosol. The analysis of biomass production revealed a range of responses, due to both biochar characteristics and soil type. Both biochars significantly increased N uptake in wheat grown in fertiliser amended ferrosol. Concomitant increase in biomass production (250% times that of control) therefore suggested improved fertiliser use efficiency. Likewise, biochar amendment significantly increased biomass in soybean and radish in the ferrosol with fertiliser. The calcarosol amended with fertiliser and biochar however gave varied crop responses: Increased soybean biomass, but reduced wheat and radish biomass. No significant effects of biochar were shown in the absence of fertiliser for wheat and soybean, while radish biomass increased significantly. Earthworms showed preference for biochar-amended ferrosol over control soils with no significant difference recorded for the calcarosol. The results from this work demonstrate that the agronomic benefits of papermill biochars have to be verified for different soil types and crops.
1,600 citations
TL;DR: In this paper, the authors provided an up-to-date assessment of global mercury emissions from anthropogenic and natural sources, including re-emission processes and primary emissions from natural reservoirs.
Abstract: . This paper provides an up-to-date assessment of global mercury emissions from anthropogenic and natural sources. On an annual basis, natural sources account for 5207 Mg of mercury released to the global atmosphere, including the contribution from re-emission processes, which are emissions of previously deposited mercury originating from anthropogenic and natural sources, and primary emissions from natural reservoirs. Anthropogenic sources, which include a large number of industrial point sources, are estimated to account for 2320 Mg of mercury emitted annually. The major contributions are from fossil-fuel fired power plants (810 Mg yr−1), artisanal small scale gold mining (400 Mg yr−1), non-ferrous metals manufacturing (310 Mg yr−1), cement production (236 Mg yr−1), waste disposal (187 Mg yr−1) and caustic soda production (163 Mg yr−1). Therefore, our current estimate of global mercury emissions suggests that the overall contribution from natural sources (primary emissions + re-emissions) and anthropogenic sources is nearly 7527 Mg per year, the uncertainty associated with these estimates are related to the typology of emission sources and source regions.
1,240 citations
TL;DR: In this article, an extensive list of low-cost adsorbents (prepared by utilizing different types of waste materials) from vast literature has been compiled and their adsorption capacities for various aquatic pollutants as available in the literature are presented.
1,044 citations
TL;DR: The results indicated that dairy manure can be converted into biochar as an effective adsorbent for application in environmental remediation.
966 citations
TL;DR: The results showed that paraxanthine, caffeine and acetaminophen were the main individual pollutants usually found in concentrations over 20 ppb, and the hydroxyl radical reaction was the major pathway for the oxidative transformation of these compounds.
849 citations
TL;DR: The recovery of the adsorbed dye from bottom ash and de-oiled soya, have been found to be 85% and 99%, respectively, and column experiments indicate practical utility of the Adsorbents for eradicating hazardous dyes from effluents.
811 citations
TL;DR: This study is a review of the recent literature on the use of natural and modified lignocellulosic residues for Cr adsorption and finds that many by-products of agriculture have proved to be suitable low cost adsorbents for Cr(VI) and Cr(III) removal from water.
782 citations
TL;DR: At environmental relevant concentrations tested in this study, biodegradation and adsorption were the major removal routes for the target antibiotics, where volatilization and hydrolysis were neglectable.
Abstract: The removal of 11 antibiotics of 6 classes, that is, two β-lactams (ampicillin and cefalexin), two sulfonamides (sulfamethoxazole and sulfadiazine), three fluoroquinolones (norfloxacin, ofloxacin, and ciprofloxacin), one tetracyclines (tetracycline), two macorlides (roxithromycin and anhydro-erythromycin), and one others (trimethoprim), in activated sludge process was investigated using two series of batch reactors treating freshwater and saline sewage respectively. At environmental relevant concentrations tested in this study, biodegradation and adsorption were the major removal routes for the target antibiotics, where volatilization and hydrolysis were neglectable. Among the 11 target antibiotics, cefalexin and the two sulfonamides were predominantly removed by biodegradation in both freshwater and saline sewage systems. Ampicillin, norfloxacin, ciprofloxacin, ofloxacin, tetracycline, roxithromycin, and trimethoprim were mainly removed by adsorption. Divalent cations (Ca2+ and Mg2+) in saline sewage sig...
763 citations
TL;DR: Preliminary growth studies indicated both fresh water and marine algae showed good growth in wastewaters, and further studies on anaerobic digestion and thermochemical liquefaction are required to make this consortium approach economically viable for producing algae biofuels.
756 citations
TL;DR: An examination ofMSW generation and composition in China is presented, providing an overview of the current state of MSW management, an analysis of existing problems in MSW collection, separation, recycling and disposal, and some suggestions for improving MSW systems in the future.
TL;DR: The evidence is nonetheless strong enough to support the provision of water supply, sanitation and hygiene for all, and the striking effect of handwashing with soap is consistent across various study designs and pathogens, though it depends on access to water.
Abstract: Background Ever since John Snow’s intervention on the Broad St pump, the effect of water quality, hygiene and sanitation in preventing diarrhoea deaths has always been debated. The evidence identified in previous reviews is of variable quality, and mostly relates to morbidity rather than mortality.
Methods We drew on three systematic reviews, two of them for the Cochrane Collaboration, focussed on the effect of handwashing with soap on diarrhoea, of water quality improvement and of excreta disposal, respectively. The estimated effect on diarrhoea mortality was determined by applying the rules adopted for this supplement, where appropriate.
Results The striking effect of handwashing with soap is consistent across various study designs and pathogens, though it depends on access to water. The effect of water treatment appears similarly large, but is not found in few blinded studies, suggesting that it may be partly due to the placebo effect. There is very little rigorous evidence for the health benefit of sanitation; four intervention studies were eventually identified, though they were all quasi-randomized, had morbidity as the outcome, and were in Chinese.
Conclusion We propose diarrhoea risk reductions of 48, 17 and 36%, associated respectively, with handwashing with soap, improved water quality and excreta disposal as the estimates of effect for the LiST model. Most of the evidence is of poor quality. More trials are needed, but the evidence is nonetheless strong enough to support the provision of water supply, sanitation and hygiene for all.
TL;DR: The present review attempts to link various compartmentalization aspects of the nanoparticles, their physical properties and toxicity in wastewater and wastewater sludge through simile drawn from other environmental streams.
TL;DR: In this paper, the problem due to the use and disposal of synthetic polymers to the environment and its solutions; in particular poly (ethylene terphthalate), is reviewed and appropriate technology and waste disposal procedures based on the socio-economic aspect to solve this problem are suggested.
Abstract: The paper reviews the problem due to the use and disposal of synthetic polymers to the environment and its solutions; in particular poly (ethylene terphthalate). Wide spread application and non-biodegradability of the PET creates huge amounts of waste and disposal, tend to a serious problem. The most important cause for recycling and reprocessing the waste PET has arisen from the awareness and concern for environmental pollution. To manage this various methods of polymer recycling has been proposed. Among them chemical recycling, i.e. hydrolysis, methanolysis, glycolysis and aminolysis are reviewed in detail. Appropriate technology and waste disposal procedures based on the socio-economic aspect to solve this problem are suggested.
TL;DR: It is revealed that water eutrophication in most lakes was initiated in the 1980s when the national economy underwent rapid development and the problem is still serious, with frequent occurrence of damaging algal blooms, which have disrupted the normal supply of drinking water in shore cities.
Abstract: Lake water eutrophication has become one of the most important factors impeding sustainable economic development in China. Knowledge of the current status of lake water eutrophicatoin and determination of its mechanism are prerequisites to devising a sound solution to the problem. Based on reviewing the literature, this paper elaborates on the evolutional process and current state of shallow inland lake water eutrophication in China. The mechanism of lake water eutrophication is explored from nutrient sources. In light of the identified mechanism strategies are proposed to control and tackle lake water eutrophication. This review reveals that water eutrophication in most lakes was initiated in the 1980s when the national economy underwent rapid development. At present, the problem of water eutrophication is still serious, with frequent occurrence of damaging algal blooms, which have disrupted the normal supply of drinking water in shore cities. Each destructive bloom caused a direct economic loss valued at billions of yuan. Nonpoint pollution sources, namely, waste discharge from agricultural fields and nutrients released from floor deposits, are identified as the two major sources of nitrogen and phosphorus. Therefore, all control and rehabilitation measures of lake water eutrophication should target these nutrient sources. Biological measures are recommended to rehabilitate eutrophied lake waters and restore the lake ecosystem in order to bring the problem under control.
TL;DR: It is demonstrated that sampling errors can lead to overinterpretation of measured data and ultimately, wrong conclusions.
Abstract: The analysis of 87 peer-reviewed journal articles reveals that sampling for pharmaceuticals and personal care products (PPCPs) and illicit drugs in sewers and sewage treatment plant influents is mostly carried out according to existing tradition or standard laboratory protocols. Less than 5% of all studies explicitly consider internationally acknowledged guidelines or methods for the experimental design of monitoring campaigns. In the absence of a proper analysis of the system under investigation, the importance of short-term pollutant variations was typically not addressed. Therefore, due to relatively long sampling intervals, potentially inadequate sampling modes, or insufficient documentation, it remains unclear for the majority of reviewed studies whether observed variations can be attributed to “real” variations or if they simply reflect sampling artifacts. Based on results from previous and current work, the present paper demonstrates that sampling errors can lead to overinterpretation of measured d...
TL;DR: It is shown that municipal landfill leachates may represent a significant source of concern for legacy, new and emerging chemicals in groundwater.
TL;DR: Overall, the sewer system appears to be a defined environment with both infiltration of rainwater and stormwater inputs modulating community composition, and microbial sewage communities represent a combination of inputs from human faecal microbes and enrichment of specific microbes from the environment to form a unique population structure.
Abstract: The release of untreated sewage introduces non-indigenous microbial populations of uncertain composition into surface waters. We used massively parallel 454 pyrosequencing of hypervariable regions in rRNA genes to profile microbial communities from eight untreated sewage influent samples of two wastewater treatment plants (WWTPs) in metropolitan Milwaukee. The sewage profiles included a discernible human faecal signature made up of several taxonomic groups including multiple Bifidobacteriaceae, Coriobacteriaceae, Bacteroidaceae, Lachnospiraceae and Ruminococcaceae genera. The faecal signature made up a small fraction of the taxa present in sewage but the relative abundance of these sequence tags mirrored the population structures of human faecal samples. These genera were much more prevalent in the sewage influent than standard indicators species. High-abundance sequences from taxonomic groups within the Beta- and Gammaproteobacteria dominated the sewage samples but occurred at very low levels in faecal and surface water samples, suggesting that these organisms proliferate within the sewer system. Samples from Jones Island (JI--servicing residential plus a combined sewer system) and South Shore (SS--servicing a residential area) WWTPs had very consistent community profiles, with greater similarity between WWTPs on a given collection day than the same plant collected on different days. Rainfall increased influent flows at SS and JI WWTPs, and this corresponded to greater diversity in the community at both plants. Overall, the sewer system appears to be a defined environment with both infiltration of rainwater and stormwater inputs modulating community composition. Microbial sewage communities represent a combination of inputs from human faecal microbes and enrichment of specific microbes from the environment to form a unique population structure.
TL;DR: Interestingly, locally enriched or evolved bacterial variants of familiar compost species were observed in both composts, and a detailed comparison of the bacterial diversity revealed a large difference in composts at the species and strain level from the different composting plants.
Abstract: Composting is an aerobic microbiological process that is facilitated by bacteria and fungi Composting is also a method to produce fertilizer or soil conditioner Tightened EU legislation now requires treatment of the continuously growing quantities of organic municipal waste before final disposal However, some full-scale composting plants experience difficulties with the efficiency of biowaste degradation and with the emission of noxious odours In this study we examine the bacterial species richness and community structure of an optimally working pilot-scale compost plant, as well as a full-scale composting plant experiencing typical problems Bacterial species composition was determined by isolating total DNA followed by amplifying and sequencing the gene encoding the 16S ribosomal RNA Over 1500 almost full-length 16S rRNA gene sequences were analysed and of these, over 500 were present only as singletons Most of the sequences observed in either one or both of the composting processes studied here were similar to the bacterial species reported earlier in composts, including bacteria from the phyla Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria and Deinococcus-Thermus In addition, a number of previously undetected bacterial phylotypes were observed Statistical calculations estimated a total bacterial diversity of over 2000 different phylotypes in the studied composts Interestingly, locally enriched or evolved bacterial variants of familiar compost species were observed in both composts A detailed comparison of the bacterial diversity revealed a large difference in composts at the species and strain level from the different composting plants However, at the genus level, the difference was much smaller and illustrated a delay of the composting process in the full-scale, sub-optimally performing plants
TL;DR: In this paper, the authors provide a synthesis of the knowledge about recovery patterns, rates and restoration effectiveness of estuarine and coastal marine ecosystems from over a century of degradation, and they show that although in some cases recovery can take <5 years, especially for the short-lived and high-turnover biological components, full recovery of coastal marine and estuarial ecosystems can take a minimum of 15-25 years for attainment of the original biotic composition and diversity may lag far beyond that period.
Abstract: Many estuarine and coastal marine ecosystems have increasingly experienced degradation caused by multiple stressors. Anthropogenic pressures alter natural ecosystems and the ecosystems are not considered to have recovered unless secondary succession has returned the ecosystem to the pre-existing condition or state. However, depending upon the scales of time, space and intensity of anthropogenic disturbance, return along the historic trajectory of the ecosystem may: (1) follow natural restoration though secondary succession; (2) be re-directed through ecological restoration, or (3) be unattainable. In order to address the gaps in knowledge about restoration and recovery of estuarine and coastal ecosystems, this special feature includes the present overview and other contributions to provide a synthesis of our knowledge about recovery patterns, rates and restoration effectiveness. From the 51 examples collated in this contribution, we refine the recovery from the list of stressors into six recovery mechanisms: (1) recovery from sediment modification, which includes all aspects of dredging and disposal; (2) recovery by complete removal of stressors limiting natural ecosystem processes, which includes tidal marsh and inundation restoration; (3) recovery by speed of organic degradation, which includes oil discharge, fish farm wastes, sewage disposal, and paper mill waste; (4) recovery from persistent pollutants, which includes chemical discharges, such as TBT; (5) recovery from excessive biological removal, related to fisheries and (6) recovery from hydrological and morphological modification. Drawing upon experience both from these many examples and from an example of one comprehensive study, we show that although in some cases recovery can take <5 years, especially for the short-lived and high-turnover biological components, full recovery of coastal marine and estuarine ecosystems from over a century of degradation can take a minimum of 15–25 years for attainment of the original biotic composition and diversity may lag far beyond that period.
TL;DR: The data indicate that compostable plastics may degrade relatively quickly compared to oxo-biodegradable and conventional plastics, and while degradable polymers offer waste management solutions, there are limitations to their effectiveness in reducing hazards associated with plastic debris.
TL;DR: Surfactants in the Environment Surfactants are a diverse group of chemicals that are best known for their wide use in detergents and other cleaning products and most of them end up dispersed in different environmental compartments such as soil, water or sediment.
Abstract: Surfactants are a diverse group of chemicals that are best known for their wide use in detergents and other cleaning products. After use, residual surfactants are discharged into sewage systems or directly into surface waters, and most of them end up dispersed in different environmental compartments such as soil, water or sediment. The toxic effects of surfactants on various aquatic organisms are well known. In general, surfactants are present in the environment at levels below toxicity and in Croatia below the national limit. Most surfactants are readily biodegradable and their amount is greatly reduced with secondary treatment in wastewater treatment plants. The highest concern is the release of untreated wastewater or wastewater that has undergone primary treatment alone. The discharge of wastewater polluted with massive quantities of surfactants could have serious effects on the ecosystem. Future studies of surfactant toxicities and biodegradation are necessary to withdraw highly toxic and non-biodegradable compounds from commercial use and replace them with more environmentally friendly ones.
TL;DR: While DAF has been used mainly in conventional type water plants, there is now interest in the technology as a pretreatment step in ultrafiltration membrane plants and in desalination reverse osmosis plants.
TL;DR: A conceptual framework for solving mine environmental issues is proposed in this article, where clean processes, or remediation measures, are designed to address environmental pollution, including coal mine accidents, land subsidence, damage to the water environment, and mining waste disposal.
Abstract: The environmental challenges from coal mining include coal mine accidents, land subsidence, damage to the water environment, mining waste disposal and air pollution. These are either environmental pollution or landscape change. A conceptual framework for solving mine environmental issues is proposed. Clean processes, or remediation measures, are designed to address environmental pollution. Restoration measures are proposed to handle landscape change. The total methane drainage from 56 Chinese high methane concentration coal mines is about 101.94 million cubic meters. Of this methane, 19.32 million, 35.58 million and 6.97 million cubic meters are utilized for electricity generation, civil fuel supplies and other industrial purposes, respectively. About 39% of the methane is emitted into the atmosphere. The production of coal mining wastes can be decreased 10% by reuse of mining wastes as underground fills, or by using the waste as fuel for power plants or for raw material to make bricks or other infrastructure materials. The proper use of mined land must be decided in terms of local physical and socio-economical conditions. In European countries more than 50% of previously mined lands are reclaimed as forest or grass lands. However, in China more than 70% of the mined lands are reclaimed for agricultural purposes because the large population and a shortage of farmlands make this necessary. Reconstruction of rural communities or native residential improvement is one environmental problem arising from mining. We suggest two ways to reconstruct a farmer's house in China.
TL;DR: An analysis of the components of applied voltage and their significance is presented from an electrochemical viewpoint to provide a fundamental understanding of the different process variables and configurations in order to identify potential improvements.
TL;DR: In this study, activated carbons were prepared from sugar beet bagasse by chemical activation and the prepared activated Carbons were used to remove nitrate from aqueous solutions and three simplified kinetic models were tested to investigate the adsorption mechanism.
TL;DR: This study represents a quantitative characterization of ARGs in lagoons across a variety of livestock operations and provides insight into potential options for managing antibiotic resistance emanating from agricultural activities.
Abstract: Although livestock operations are known to harbor elevated levels of antibiotic resistant bacteria, few studies have examined the potential of livestock waste lagoons to reduce antibiotic resistance genes (ARGs). The purpose of this study was to determine the prevalence and examine the behavior of tetracycline [tet(O) and tet(W)] and sulfonamide [sul(I) and sul(II)] ARGs in a broad cross-section of livestock lagoons within the same semiarid western watershed. ARGs were monitored for one year in the water and the settled solids of eight lagoon systems by quantitative polymerase chain reaction. In addition, antibiotic residues and various bulk water quality constituents were analyzed. It was found that the lagoons of the chicken layer operation had the lowest concentrations of both tet and sul ARGs and low total antibiotic concentrations, whereas sul ARGs were highest in the swine lagoons, which generally corresponded to the highest total antibiotic concentrations. A marginal benefit of organic and small dairy operations also was observed compared to conventional and large dairies, respectively. In all lagoons, sul ARGs were observed to be generally more recalcitrant than tet ARGs. Also, positive correlations of various bulk water quality constituents were identified with tet ARGs but not sul ARGs. Significant positive correlations were identified between several metals and tet ARGs, but Pearson's correlation coefficients were mostly lower than those determined between antibiotic residues and ARGs. This study represents a quantitative characterization of ARGs in lagoons across a variety of livestock operations and provides insight into potential options for managing antibiotic resistance emanating from agricultural activities.
TL;DR: Sawdust, an available and renewable biomass, was investigated as a novel ammonium biosorbent and suggested that the main mechanisms involved in the removal of ammonium might be the ionic exchange and complexation.
TL;DR: The mass inventories of TCS and TCC in the Pearl River system indicate that the sediments are not only an important sink but also a potential source for the two compounds in surface water.
TL;DR: In this article, the state of knowledge and technology in thermal methods for the utilization of municipal sewage sludge to obtain useful forms of energy such as pyrolysis, gasification, combustion, and co-combustion.