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1.
In this paper, a new methodology is developed for optimization of water and waste load allocation in reservoir–river systems considering the existing uncertainties in reservoir inflow, waste loads and water demands. A stochastic dynamic programming (SDP) model is used to optimize reservoir operation considering the inflow uncertainty, and another model called PSO-SA is developed and linked with the SDP model for optimizing water and waste load allocation in downstream river. In the PSO-SA model, a particle swarm optimization technique with a dynamic penalty function for handling the constraints is used to optimize water and waste load allocation policies. Also, a simulated annealing technique is utilized for determining the upper and lower bounds of constraints and objective function considering the existing uncertainties. As the proposed water and waste load allocation model has a considerable run-time, some powerful soft computing techniques, namely, Regression tree Induction (named M5P), fuzzy K-nearest neighbor, Bayesian network, support vector regression and an adaptive neuro-fuzzy inference system, are trained and validated using the results of the proposed methodology to develop real-time water and waste load allocation rules. To examine the efficiency and applicability of the methodology, it is applied to the Dez reservoir–river system in the south-western part of Iran.  相似文献   

2.
This literature review surveys the previous and current researches on the co-digestion of anaerobic processes and examines the synergies effect of co-digestion with cattle manure. Furthermore, this review also pays attention to different operational conditions like operating temperature, organic loading rate (OLR), hydraulic retention time (HRT), chemical oxygen demand (COD) and volatile solid (VS) removal efficiency and biogas or methane production. This review shows that anaerobic mono-digestion of cattle manure usually causing poor performance and stability. Anaerobic studies were generally performed under mesophilic conditions maintained between 35 and 37 °C. Organic waste loading rate generally ranges from 1 to 6 g VS–COD L?1 day?1 stable condition in anaerobic digester. Generally, studies show that HRT for co-digestion of fruit–vegetables waste and industrial organic waste appears to exceed 20 days. However, the anaerobic co-digestion process is generally operated at HRT of between 10 and 20 days. VS and COD removal efficiency usually reaches up to 90 % due to co-digestion with different type organic waste. Methane–biogas production is generally obtained between 0.1 and 0.65 L CH4–biogas g?1 VS.  相似文献   

3.
Gao  Wu  Kavazanjian  Edward 《Acta Geotechnica》2022,17(1):37-63
Acta Geotechnica - A constitutive model is developed to describe the stress–strain–time behavior for decomposing municipal solid waste (MSW) within a critical state soil mechanics...  相似文献   

4.
This work aims to assessment of the calcitic ornamental stone waste for the stabilization of expansive soil. Calcitic rock-derived waste together with different expansive soils from Egypt were characterized and processed for stabilizer optimization. The mineral, chemical and engineering characteristics of the waste and the soil samples were examined using XRD, DTA, TGA, SEM, XRF as well as geotechnical characteristics such as liquid, plastic and shrinkage limits, plasticity index, free swelling, and uni-axial compressive strength, respectively. The calcitic waste has been calcined in an electrical muffle furnace at 1000℃ for 1 hour. The samples were treated by 0–8% waste post calcination for soaking time1– 4 weeks.  相似文献   

5.
The mineralized district of SW England was one of the world's greatest mining areas, with mining commencing in the Bronze age, peaking in the 1850s to 1890s, but still continuing to the present day. Consequently, it is not surprising that mining has had a major impact on the environmental geochemistry of SW England. In this study, the mineralogical and geochemical signature of mine waste contamination within the Fal Estuary at Tresillian, Cornwall, has been examined. A pulse of mine waste contamination is recognized at approximately 50?cm below present day sediment surface. Sn, As, Cu, Pb, and Zn are all enriched within this contaminated interval with up to 1800 mg?kg–1 Sn, 290 mg?kg–1 As, 508 mg?kg–1 Pb, 2210 mg?kg–1 Zn, and 1380 mg?kg–1 Cu. Within this interval, the dominant minerals present include chalcopyrite, arsenopyrite, pyrite, cassiterite, Fe–Ti oxides (ilmenite and ?rutile), wolframite, sphalerite, baryte, zircon, monazite, tourmaline and xenotime. In addition, man-made slag products commonly occur. The exact timing of the release of mine waste into the estuary is poorly constrained, but probably occurred during or immediately following the peak in mining activity in the nearby Camborne-Redruth district, which was between 1853 and 1893. The mine waste may have entered the estuary either via the Tresillian River and its tributaries or via Calenick Creek and the Truro River and/or the Carnon River which flows into Rostronguet Creek.  相似文献   

6.
Waste engine oil causes a vital environmental pollution when it spill during change and transportation and products of waste engine oil causes lethal effects to the living systems. Thus, abiotic and biotic approaches are being extensively used for removal of waste engine oil pollution. Therefore in present study, waste engine oil degradation was accomplished by a new bacterial culture, isolated from the soil by an enrichment technique. Morphological, biochemical and gene sequence analysis revealed that isolate was Bacillus cereus. Subsequently, biodegradation potential of B. cereus for waste engine oil was studied. Experimental variables, such as pH, substrate concentration, inoculum size, temperature and time on the biodegradation, were checked in mineral salt medium. The biodegradation efficiency of B. cereus was determined by gravimetry, UV–visible spectrophotometry and gas chromatography. In addition, waste engine oil was also characterized by GC–MS and FTIR for its major constituents, which showed total 38 components in waste engine oil, including hopanes, benzopyrene, long-chain aliphatic hydrocarbons, dibenzothiophenes, biphenyl and their derivatives. Results of successive biodegradation indicated that B. cereus was capable to degrade 1% of waste engine oil with 98.6% degradation potential at pH 7 within 20 days. Hence, B. cereus presents an innovative tool for removing the engine oil from the contaminated area.  相似文献   

7.

Despite significant recent advancements in the sensor technologies, the use of sensors for raw material characterization in the mining industry remains limited. The aim of the present study was to assess the utility of applying the mid-wave infrared (MWIR) reflectance data acquired by the use of a handheld Fourier-transform infrared spectrometer (FTIR), combined with partial least squares-discriminant analysis (PLS-DA), for the characterization of a polymetallic sulphide ore deposit. In achieving the study objectives, focus was given to the MWIR portion of the FTIR dataset, as it is the least explored region of the infrared spectrum in mineral characterization studies. Three datasets—covering different wavelength ranges—were generated from the FTIR spectral data, namely the full FTIR range (2.5–15 µm), MWIR (2.5–7 µm) and long-wave infrared (LWIR: 7–15 µm), in order to investigate the associated information level of each defined wavelength region separately. Design of experiment was developed to determine the optimal data filtering techniques. Using the processed data and PLS-DA, a series of calibration and prediction models were developed for ore and waste materials separately. As the models applied to the MWIR data showed a successful classification rate of 86.3% for sulphide ore–waste discrimination, similarly using the full spectral FTIR dataset, a correct classification rate of 89.5% was achieved. This indicates that MWIR spectral range includes informative signals that are sufficient for classifying the material into ore or waste. The proposed approach could be extended for automating the sulphide ore–waste discrimination process, thus greatly benefiting marginally economical mining operations.

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8.
This paper aims at investigating some physical and mechanical characteristics of cemented tailings paste incorporating different amounts of crushed waste rocks (hereinafter called paste aggregate fill, PAF) for underground stope filling. Different mixture formulations were prepared with three classes of crushed waste rocks (or aggregate) grain size, namely 0/10, 0/15 and 0/20 mm. The amount of crushed waste rocks in the PAF mixtures ranges from 10 to 50% by volume (% v/v) (or 8–45% by mass, %m) of dry mill tailings and crushed waste rocks. The results show that the addition of crushed waste rocks in cemented tailings paste mixtures allows a significant unconfined compressive strength (UCS) development after 28 and 90 days of curing. The highest UCS was obtained from the mixtures containing 50% v/v of crushed waste rocks of class of size 0/15 mm. The PAF mixtures with the coarser crushed waste rocks (class of size of 0/20 mm) exhibit some particles segregation.  相似文献   

9.
In recent years, geotechnical engineers are using tyre waste to alter the properties of soil for providing sustainable solutions to complex engineering problems. It is noted that black cotton soil, which is expansive in nature, covers a major portion of the Indian sub-continent, such as the Deccan plateau, Malwa plateau and a portion of Gujarat and poses challenging problems to infrastructural development in the region. In the present study, authors have characterised the geotechnical properties of black cotton soil, which is partially replaced with 4.75 mm passing – 2 mm retained (coarse fraction) and 2.0 mm passing - 75 micron retained (fine fraction) shredded tyre waste. The results of the experimental studies clearly show that partial replacement of black cotton soil with shredded tyre waste alters the geotechnical properties favourable to engineering applications and greatly reduces the swelling potential of the black cotton soil. It is noted that instead of fine fraction (2.0–0.075 mm), replacement with coarse fraction (4.75–2.00 mm) of shredded tyre waste can better be used for light weight fill behind the retaining walls as well as for embankment construction as it helps in reducing swelling pressure as well as improving the strength properties.  相似文献   

10.
Three large-scale instrumented waste rock piles were constructed at the Diavik Diamond Mine in the Northwest Territories, Canada. These experimental waste rock piles (test piles) are 15 m high and are part of an integrated field and laboratory research program to characterize and compare low-sulfide waste rock and drainage at various scales. During test pile construction, samples of the <50 mm fraction of waste rock were collected from two types of waste rock that are segregated during mining operations based on S content. The samples were analyzed for S content and particle size distribution. One test pile contained waste rock with an average of 0.035 wt.% S in the <50 mm fraction, within the operational S target of <0.04 wt.% S for the lower S waste rock type. The second test pile contained waste rock with an average of 0.053 wt.% S in the <50 mm fraction, lower than the operational S target of >0.08 wt.% S for the higher S waste rock type. The third test pile has a low permeability till layer and a low sulfide waste rock thermal layer covering a core of waste rock with average 0.082 wt.% S in the <50 mm fraction, which is within the operational S target of >0.08 wt.% S for the higher S waste rock. Particle size distributions for the lower and higher S waste rock are similar, but the higher S waste rock has a higher proportion of fine-grained particles. Sulfur determinations for discrete particle sizes of the <50 mm fraction illustrate higher S concentrations in smaller particles for both the lower S waste rock and the higher S waste rock. Similarly, S concentrations calculated for the >10 m scale, from composite blast hole cuttings, are lower than those calculated for the <50 mm scale. Acid–base accounting using standard methods and site-specific mineralogical information was used to calculate the ratio of neutralization potential to acid generating potential. A comparison of calculation approaches to pH and alkalinity data from humidity cell and test pile effluent suggest that ratios are very sensitive to the calculation method. The preferred calculation method was selected by comparing calculation results to pH and alkalinity data from humidity cell effluent collected over 95 weeks and test pile effluent collected over five field seasons. The preferred acid–base accounting values were obtained by calculating the average neutralization potential divided by the average acid potential of a sample set. This approach indicates that waste rock with >0.05 wt.% S is of uncertain acid-generating potential and effluent data indicate this waste rock generates acidic effluent; whereas lower S waste rock does not produce acidic effluent, consistent with the acid–base accounting predictions.  相似文献   

11.
The decontamination of buried wastes of the Tyrnyauz Tungsten–Molybdenum Plant is complicated by the geochemical features of the waste composition: low sulfide and high carbonate content, polyelemental composition, and considerable amounts of technogenic admixtures (kerosene, oils, soda, and soluble glasses). These circumstances result in sufficient complication of the suggested technology of waste treatment, including the sulfuric-acid leaching and separate sorption recovery of hazardous and useful elements from the working solution.  相似文献   

12.
Chen  Yong-Gui  Cai  Ye-Qing  Pan  Kan  Ye  Wei-Min  Wang  Qiong 《Acta Geotechnica》2022,17(5):1879-1896
Acta Geotechnica - Compacted Gaomiaozi bentonite–sand mixtures are regarded as attractive buffer/backfill materials for nuclear waste deep geological disposal. When the mixture blocks are...  相似文献   

13.
Activated carbon is the adsorbent commonly used to remove arsenic from contaminated water. However, the problem is that it is not always available everywhere and considered expensive in developing countries. An inexpensive alternative to activated carbon can therefore aid the adequate treatment of contaminated water. Tea waste, water hyacinth and banana peel are investigated extensively in this study as the inexpensive alternative. Tea waste treated with a right proportion of aqueous FeCl3 reagent is found to have substantially higher arsenic removing capacity (which is quantified by arsenic concentrations measured employing Double Beam Atomic Absorption Spectrophotometer) than the other two. The comparison made subsequently between tea waste and activated carbon reveals the feasibility of the utilization of tea waste. The arsenic removing capacity of tea waste treated with the right proportion of aqueous FeCl3 reagent is found to be equal to that of the activated carbon treated with the same reagent over the continuous operative time of 2 h. The tea waste treated rightly with the same reagent also removes arsenic at acceptable capacities over extended operative times such as 4–6 h. It is therefore proposed to consider tea waste as the inexpensive alternative to activated carbon in treating arsenic contaminated water.  相似文献   

14.
Doklady Earth Sciences - The properties of the potential matrix of the REE–actinide fraction of high-level radioactive waste have been studied. A sample containing 2 wt % of curium was...  相似文献   

15.
Secondary treated sewage was chlorinated to a residual level of 2–10 mg/l in a continuous flow system in the laboratory and diluted to various levels with estuarine water. A portion of the chlorinated sewage effluent was dechlorinated with sodium thiosulfate and the dechlorinated waste was diluted with estuarine water in the same proportions as the chlorinated waste.Menidia menidia, Palaemonetes pugio andCrassostrea virginica were exposed to chlorinated and dechlorinated treatments. High concentrations of chlorinated effluent caused mortalities inM. menidia andP. pugio, whereas similar concentrations of dechlorinated wastes did not cause mortalities. Mortalities in the chlorinated waste are correlated with chlorine residuals. Similarly, the chlorinated wastes depressed the shell deposition rate ofC. virginica below 50% of controls at all doses. Dechlorinated waste allowed shell deposition greater than 50% of controls. However, the occurrence of some growth inhibition inC. virginica exposed to dechlorinated waste suggests the presence of toxic material in the waste other than chlorine.  相似文献   

16.
The behavior of the Gimpo #2 landfill, which is an active landfill and the largest in Korea, is analyzed using field measurement data obtained from various field instruments installed within the landfill. The data included in this analysis are the leachate head within the landfill, waste load data using soil pressure plate and settlement data from settlement plate on the surface of the waste of each stage fill including the settlement of the soft foundation clay soil. Landfill blocks are selected both near the embankment and in the center area of the landfill. The analysis of the field-monitored data showed that the leachate head increase was negligible near the embankment. It was significant in the central block as the waste loads increase and reached 15 m at the fourth stage of waste disposal. The reason that the leachate head is higher in the central block than near the embankment is due to the long drainage path and the loss of gradient of drain pipes. The range of unit weight of the waste converted from the measurement data of earth pressure cell was 0.91–1.24 t/m3 and the average value was 1.05 t/m3. The values reflect well the waste compositions recently buried in GML #2, since from 1998 the waste disposed in GML #2 did not contain food waste. The magnitude of final settlements that occurred in each stage loading of 5 m thickness in the peripheral block was very close to 120 cm. The settlement rate of the waste by dividing the thickness of waste was 24 %. This rate can be divided into 10 % by waste loading and 14 % by waste decomposition. The delay of settlements is recognized in each waste layer for second and third loading in the central block due to the accumulation of leachate within the landfill.  相似文献   

17.
Compacted soil–bentonite mixtures are finding wide application as buffer material for waste repositories for their favorable self-sealing qualities. The swelling properties of such materials which serve as a measure of their self-sealing capabilities and, thus, the efficiency of the repository in sealing off their contents from the environment are closely related to the chemistry of the leachate that emanate from the wastes. For this reason, the swelling parameters (namely swelling potential and pressure) of compacted lateritic soil–bentonite mixtures under consideration for use as barrier in municipal waste landfill were evaluated. Series of swelling potential and pressure tests were performed using variable content (0–10 %) of bentonite at predetermined optimum moisture content. Soil mixtures were compacted with British Standard Heavy compactive effort and saturated with processed tap water as well as three leachate solutions of varying ionic strength that were generated in active open dump landfills. Experimental results showed that swelling potential based on the free swell together with the maximum swell pressures of compacted soil mixtures measured at equilibrium increased approximately linearly with increase in the amount of bentonite when inundated with processed tap water and the three leachate solutions. On the other hand, these swelling parameters decreased as the ionic strength of the leachate solutions measured by their electrical conductivity increased for the various soil mixtures. These results provide an insight into the swelling behavior and the possible degradation in the efficiency of the proposed lateritic soil–bentonite mixtures in relation to their use as buffer material in waste landfills.  相似文献   

18.
Leachate was a major cause of high risk classification. This landfill was set as one with highest possible risk classification due to high vulnerability of private water wells to contamination from leachate flows. The aim of this study is to determine the present and possible environmental risks of the leachate spreading from solid waste dumping site in Tunceli and offer solutions for those determined environmental risks. For this purpose, the characteristics of the leachate were monitored at two station points detected in the solid waste dumping site for 7 months. The characteristics of the leachate were found for pH between 7.9 and 8.7. Oxidation reduction potential (ORP) occurred between ??143 and ??48 mV while conductivity was between 2.8 and 2.6 mS. Total solid matter (TSM) and suspended solid matter (SSM) were between 1000 and 7000 mg/l, 0.2–22.5 mg/l, respectively, while total volatile solids (TVS) occurred between 300 and 1800 mg/l for the two stations. Alkalinity was approximately between 290 and 5210 mg/l, while biological oxygen demand (BOD5) and chemical oxygen demand (COD) results were 15–606 mg/l and 60–1160 mg/l, respectively, for two stations in all sampling time. In both stations, orthophosphate, ammonium nitrogen, nitrate, sulfate, and chloride analyses stayed between 3.04 and 921.1 mg/l; 0.29–619.36 mg/l; 8.94–135.04 mg/l; 125.9–1360.9 mg/l and 99.9–1249.9 mg/l, respectively, in 6 months. As a result of the characterization studies obtained from the leachate, it was found that the amounts of water entering into the waste mass and the retention period of the water in the mass were very effective in the temporal character change of the leachate. According to the Discharge Standards for Solid Waste Assessment and Disposal Facilities and Discharge to Waste Water Infrastructure Facilities of waste management regulation, the results were found to be risky. Consequently, the site in question needs to be urgently rehabilitated when considering the environmental risks of the leachate spreading from the site.  相似文献   

19.
Meng  Hao  Shu  Shuang  Gao  Yufeng  He  Jia  Wan  Yukuai 《Acta Geotechnica》2021,16(12):4045-4059

Kitchen waste and wind erosion are two worldwide environmental concerns. This study investigated the feasibility of using kitchen waste for Sporosarcina pasteurii cultivation and its application in wind erosion control of desert soil via microbially induced carbonate precipitation (MICP). Enzymatic hydrolysis was adopted to improve the release and recovery of protein in kitchen waste for subsequent microorganism production. After conditions optimized, the maximum biomass concentration (OD600) and urease activity of Sporosarcina pasteurii in the kitchen waste-based medium reached 4.19, and 14.32 mM urea min?1, respectively, which were comparable to those obtained in conventional standard media. The harvested Sporosarcina pasteurii was then used to catalyze the precipitation of calcium carbonate in the desert soil, and its performance in wind erosion control was evaluated through wind tunnel tests. The microbially mediated calcium carbonate could significantly decrease wind erosion loss of the desert soil even after 12 wet–dry or freeze–thaw cycles. Scanning electron microscopy (SEM) with energy-dispersive X-ray (EDX) confirmed the bridge effect of calcium carbonate crystals in the soil matrix. The kitchen waste, as a cost-effective alternative nutrient for bacterial cultivation and carbonate precipitation, showed great potential for large-scale applications in wind erosion control of desert soils.

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20.
Portland cement has been suggested as an effective stabilization (physico-chemical) method for hazardous waste. This research explored the immobilization of metals in various mixtures of Portland cement and fly ash waste sampled from coal power plant in the province of Lodz, central Poland. The stabilization of fly ash in Portland cement was investigated under a wide range of pH conditions (3–12). Leachability tests were used to determine the efficiency of the encapsulation by studying the dissolution of alkaline metals (sodium, potassium) and alkaline earth metals (calcium, magnesium). The lowest value of leached metals was obtained for ratio of ash to cement of 1:10 in a case of sodium and calcium, while ratio 1.5 gave the lowest leached effects for potassium and magnesium. The high effectiveness of solidification/stabilization process was gained in high pH values (9–11).  相似文献   

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