Phosphorus Waste Research Articles

Production performance, nutrient digestibility, serum biochemistry, fillet composition, intestinal microbiota and environmental impacts of European perch (Perca fluviatilis) fed defatted mealworm (Tenebrio molitor)

Yellow mealworm (Tenebrio molitor) larvae meal (TM), one of the seven insect species approved for use in aquafeed in Europe, is a frequently investigated candidate for fish diets. This study aimed to investigate the effects of dietary defatted TM on production performance, serum biochemistry, nutrient digestibility, fillet traits, intestinal microbiota, and environmental impacts of perch (Perca fluviatilis). Four experimental diets, characterized by defatted TM inclusion levels of 0, 6.8, 13.5 and 20.3%, respectively, or 0, 25, 50, and 75% replacement for fishmeal on a w/w basis (TM0, TM25, TM50, and TM75, respectively), were fed to juvenile perch (bodyweight 20.81 ± 3.36 g, total length 117.7 ± 7.2 mm) (quadruplicated per diet) for 105 days. Inclusion levels of 6.8% or 25% fishmeal replacement by defatted TM did not show a significant effect on specific growth rate and feed conversion ratio, while further levels of 13.5 and 20.3%, or 50 and 75% fishmeal replaced by defatted TM, respectively, displayed a significant delay in the former (P = 0.01), but increase in the latter indice (P = 0.04) compared to TM0 diet. The aspartate aminotransferase activities in perch's serum increased with increasing dietary TM (P = 0.02). Protein digestibility of perch exhibited a negative correlation with dietary TM (P = 0.03). Dietary defatted TM did not, alter fillet composition of perch (P > 0.05) and modify diversity of fish gut microbiota (Chao1 index, P = 0.742; Shannon index, P = 0.557; and observed species, P = 0.522), but significantly reduced abundance of Lactobacillus (P = 0.04) and Streptococcus (P = 0.01). Diets containing more than 6.8% TM generated a comparable amount of total solid waste and solid phosphorus waste as the TM0, whereas solid nitrogen waste significantly increased with elevated TM levels (P < 0.001). The estimated environmental impacts of perch fed TM25 were comparable to TM0 for global warming potential, acidification, and land use (P > 0.05), whereas TM50 and TM75 exerted heavier burdens on energy use, eutrophication, and water use than TM0 (P < 0.001). Fishmeal replacement by TM significantly reduced the economic fish-in fish-out ratio (P < 0.001). Results of this multidisciplinary study revealed important considerations for formulating diets with insect meals and their potential effects on fish performance and environmental impacts.

The optimal feeding frequency for largemouth bass (Micropterus salmoides) reared in pond and in-pond-raceway

Largemouth bass is a carnivorous fish commercially important for freshwater aquaculture worldwide, however, the optimal feeding regime for the fish reared in pond has not been established. The present study examined feed intake, growth, feed utilization, body composition and waste outputs of largemouth bass fed at different feeding frequencies in pond and in-pond-raceway (IPR). Two 10-week feeding trials (I and II) were conducted simultaneously. Fish were fed at 1, 2, 3 or 4 meal d−1 in pond (trial I), and were fed at 2 or 3 meal d−1 in either pond or IPR (trial II). The initial body weight was 43.0 ± 0.2 g fish−1. In trial I, weight gain increased with increasing feeding frequency from 1 to 3 meal d−1, but no significant difference was found in weight gain between fish fed at 2, 3 and 4 meal d−1. The lowest retention efficiencies of nitrogen (NRE) and phosphorus (PRE) and the highest feed intake and phosphorus waste occurred in fish fed at 4 meal d−1. In trial II, no significant difference was found in weight gain between fish fed at 2 and 3 meal d−1 in IPR, while NRE, PRE and energy retention efficiency (ERE) were lower in fish fed at 3 meal·d−1 than in fish fed at 2 meal d−1. Weight gain, NRE, PRE and ERE were lower, while feed intake, body lipid content, wastes of nitrogen, phosphorus and carbon were higher, in fish reared in IPR than in fish fed at the same feeding frequency in pond. The present study indicates the optimal feeding frequency was 3 meal d−1 for largemouth bass reared in pond, and 2 meal d−1 for the fish reared in IPR. According to production performance, the IPR should not be an appropriate grow-out system for commercial largemouth bass farming.

Environmental consequences of using insect meal as an ingredient in aquafeeds: A systematic view

AbstractWe retrieved data from various studies to investigate the consequences of insect meal production and insect meal‐based diets with respect to their environmental impact, including global warming potential, energy use, land use, water use, acidification, eutrophication as well as to economic fish‐in fish‐out ratio and solid waste output production. Analysis indicated that insect meals’ production exerted positive effects on land use but was associated with greater energy use and a larger carbon footprint compared to conventional protein sources. Substitution of silkworm meal (Bombyx mori) meals for fishmeal in aquatic animal diets significantly reduced solid phosphorus waste compared to insect‐free diets. In contrast, the inclusion of black soldier fly (Hermetia illucens), housefly (Musca domestica), mealworm (Tenebrio molitor) and grasshopper (Zonocerus variegatus) has led, in comparison to insect‐free diet, to greater solid nitrogen waste. Reducing the proportion of fishmeal and, to a lesser extent fish oil, by various insect meals in aquatic diet formulations significantly reduces economic fish‐in fish‐out, indicating less marine forage fish required per unit fish yield. The simulated data showed environmental benefit associated with land use of insect‐containing aquafeeds compared to insect meal‐free feeds, especially insect species of M. domestica and T. molitor. In all, this study suggested a trade‐off of using insect meal as an aquafeed ingredient regarding environmental consequence. Since insect meal has excellent potential to supply protein for aquafeeds in the coming years, improvement in insect meal production systems and nutritional composition will be essential to make insect meal a sustainable aquafeed ingredient.

Toward environmentally sustainable aquafeeds

Aquaculture is the fastest growing food production sector and currently supplies almost 50% of fish for human consumption worldwide. There are significant barriers to the continued growth of industrial aquaculture, including high production costs and harmful environmental impacts associated with the production of aquaculture feed. Most commercial aquaculture feeds are based on fish meal, fish oil, and terrestrial plant ingredients, which contain indigestible forms of phosphorus. Phosphorus loading from aquaculture effluent can lead to eutrophication in aquatic ecosystems. Formulating fish feeds using ingredients that contain highly bioavailable forms of phosphorus in nutritionally appropriate quantities will reduce phosphorus loading. Using both in vivo and in vitro experiments, we examined the digestibility of phosphorus in three experimental tilapia feeds supplemented with two freshwater microalgae (Spirulina sp., Chlorella sp.) and one marine microalga, Schizochytrium sp., relative to a reference diet containing fish meal and fish oil. We also calculated a phosphorus budget to quantify metabolic phosphorus waste outputs. The marine Schizochytrium-supplemented diet had the highest phosphorus digestibility and the lowest solid phosphorus discharge compared to the reference diet and the other experimental diets. The Schizochytrium ingredient also had the highest phosphorus digestibility among the three microalgae tested in vitro experiments. These results suggest that Schizochytrium sp. is a highly digestible source of phosphorus and findings on metabolic phosphorus waste outputs have implications for the formulation of sustainable diets for tilapia. Further research must examine the economic feasibility and environmental impacts of producing Schizochytrium sp. as an aquafeed ingredient.

Analisa Limbah Fosfor Kegiatan Keramba Jaring Apung di Danau Laut Tawar Aceh Tengah

Floating net cage activities can cause water quality to decrease. The feed remains and the metabolism of the fish from these activities produces nitrogen and phosphorus . The objective of this study is to obtain the calculation model and the amount of phosphorus released into the waters of Laut Tawar Lake as a result of floating cage activities. The resulting formula was Pw = (F x [P]p) – ((It – Io) x [P]i), where their variables were given feed (F), phosphorus concentration of feed ([P]p), the final weight of fish (It), the initial weight of fish (Io), and phosphorus concentration in fishes ([P]i). It can be used to predict the increase in phosphorus waste based on the increase in floating net cage area. The weight of tilapia increases exponentially with the day of cultivation in the equation Y = 12.70e0.02x and the goldfish followed the formula Y = 2.28e0.03x. Phosphorus in tilapia varies from 1.58% to 2.23% with an average of 1.97%. Goldfish contain 1.19 - 2.02% phosphorus, with an average of 1.52%. Goldfish growth was not optimal due to inadequate feeding, so without excessive feeding and did not generate phosphorus waste. The cultivation of tilapia releases 0.09 Kg P/m2 of phosphorus waste from floating cages .

Replacement of fish meal with gamma‐ray irradiated soybean meal in the diets of largemouth bass Micropterus salmoides

This study evaluates the potential to replace fish meal with gamma-ray (γ) irradiated soybean meal (SM) in the diet of largemouth bass (Micropterus salmoides) and the role of brewer's yeast (Saccharomyces cerevisiae) supplementation in fish meal replacement. The reference diet (490 g kg−1 crude protein, 90 g kg−1 lipid and 400 g kg−1 fish meal) was formulated into six isoproteic and isolipidic experimental diets. In the first three diets (S20, S40 and S60), 20%, 40% and 60% of fish meal in the reference diet was replaced with γ-irradiated SM, respectively. The brewer's yeast was then supplemented to diets S20, S40 and S60 at 10 g kg−1 to form other three diets (SY20, SY40 and SY60). The feeding trial lasted 8 weeks. Fish weight gain was not affected by the level of fish meal replacement, yeast supplementation and their interactions. Fish meal replacement and yeast supplementation significantly affected feed intake, feed conversion ratio (FCR), retention efficiencies of nitrogen (NRE) and phosphorus (NRE), nitrogen waste, phosphorus waste and the ratio of fish meal consumption to fish production (RCP). The hepatosomatic index and body contents of moisture and lipid were dependent on the level of fish meal replacement. The contents of protein, ash and phosphorus in the whole body depended on fish meal replacement and the interaction between fish meal replacement and yeast supplementation. No significant difference was found in weight gain between fish fed the reference diet and six experimental diets. Feed intake and FCR were lower in fish fed the reference diet than those fed diets S20, S40, S60, SY20 and SY60. However, feed intake, FCR, NRE and nitrogen waste in fish fed diet SY40 did not differ from those fed the reference diet. The RCP declined with the decrease of dietary fish meal. This study indicates that the γ-irradiated SM is a promising ingredient as a fish meal substitute. Fish meal can be reduced to 160 g kg−1 with γ-irradiated SM as the substitute in the largemouth bass diet. The supplementation of S. cerevisiae at 10 g kg−1 did not show a positive role for the reduction of fish meal in the largemouth bass diet.

Микрофлора фосфорсодержащих отходов южного казахстана

The article presents the results of microbiological studies of phosphorus-containing wastes. 70 isolates&nbsp;were isolated, of which 36 isolates were assigned to bacteria, which corresponds to 51% of the total number&nbsp;of isolated microorganisms, 7 isolates were assigned to actinomycetes (10%) and 3 cultures to yeast&nbsp;(4%), 24 isolates were assigned to micromycetes (35%). Based on the screening of microorganisms, 14 of&nbsp;the most active strains that are promising for biogeotechnological purposes were selected. Based on the&nbsp;results of the study of cultural characteristics and PCR analysis data, the isolated strains were assigned to&nbsp;such types of micromycetes as: Aspergillus niger AsIA, Aspergillus tubingensis AsPN, Aspergillus terreus&nbsp;JOM, Aspergillus flavus AsZ, Aspergillus flavus AsF, to denitrifying bacteria Pseudomonas stutzeri NJA,&nbsp;to thermophilic bacteria Methyloversatilis thermotolerans MSO, Nitrosomonas europeae Nit1, Ralstonia&nbsp;pickettii ASA and Ralstonia pickettii TS, Acinetobacter sp. NAO, Alicyclobacillus tolerans ST (Sulfobacillus&nbsp;thermosulfidooxidans), Zoogloea resiniphila NS1, Gallionella capsiferriformans TS2, to acidophilic bacteria&nbsp;strains: Acidithiobacillus ferrooxidans ThIO, Acidithiobacillus thiooxidans ThIO .Key words: phosphorus waste, Acidithiobacillus ferrooxidans, Aspergillus niger, Nitrosomonas europeae,&nbsp;Gallionella capsiferriformans, Sulfobacillus thermosulfidooxidans.

Waste-to-resource strategy to fabricate environmentally benign flame retardants from waste phosphorus tailings

Abstract Environmentally benign magnesium hydroxide (MH) flame retardants with different morphologies were prepared from waste phosphorus tailings by a combination of acidolysis reaction and hydrothermal method. The morphology, structure and dispersibility of MH were characterized by X-ray power diffraction, scanning electron microscope, and transmission electron microscope. The influences of the synthesized MH on the flame retardancy and smoke suppression properties of thermoplastic polyurethane were studied by cone calorimeter test and the flame retardant mechanism was discussed.

Italmatch to recover waste phosphorus

The specialty chemical maker Italmatch has agreed to acquire RecoPhos Project Technology, a technology to recover elemental phosphorus from waste streams, from Israel Chemicals and partners. The Italian firm plans to continue developing the technology and use it to recover phosphorus from sewage sludge ash and other waste. Italmatch, which produces phosphorus derivatives, says supplies of natural phosphate ore are finite.

Microbiological analysis of phosphorus-containing waste in the southern region

The article presents the physical, chemical and microbiological quantitative and qualitative characteristics of phosphorus-containing man-made waste (slags and sludges)&nbsp;of the former Shymkent phosphorus plant in the South of Kazakhstan. The study found that slurries and slags of phosphorus-containing waste have a pH of 6-7,5&nbsp; and such components as SiO2-quartz, CaCO3 –calcite, and Fe2O3 –hematite predominate in the composition of surface eroded waste. The following groups of microorganisms were identified in the composition of phosphorus waste: micromycetes in quantity (5,4±0,5)×10CFU/g, heterotrophs-in the amount of–(3,8 ±0,3) ×104 CFU/g, phase 1 nitrifiers -108 CFU / g, nitrogen-fixing bacteria-in quantity 90 % &nbsp;fouling of lumps, actinomycetes-in quantity 105 CFU/g, enterobacteria-in quantity 107 CFU/g. Anaerobes in slag samples -3, 8x104 CFU / ml, and in sludge samples -0, 50x102 CFU / ml, that is, the number of anaerobic microorganisms is less than aerobes.Thionic and sulfur-oxidizing bacteria were not detected in the phosphorus-containing waste. As a result of screening work, 73 isolates of microorganisms that are promising for biogeotechnological purposes were isolated. Keyword:&nbsp;microorganisms, bio-leaching, phosphorus-containing waste, slag, sludge.

Effects of oilseed meals on pellet characteristics, faecal matter production, postprandial ammonia and phosphorus excretion rates in Nile tilapia, Oreochromis niloticus

ABSTRACT This study assessed the physical characteristics, faecal, ammonia and phosphorus waste production rates of mixtures of groundnut, cottonseed, copra and soybean meals as a replacement for fishmeal in Nile tilapia diets. Six experimental diets were formulated such that the oilseed mixtures contributed 80% of total dietary protein. A fishmeal-based diet served as the control. The diets were randomly assigned in triplicates to the experimental tanks, containing 15 juvenile tilapia with a bulk weight of ∼1 kg. Ammonia and phosphorus excretion rates of the diets were monitored at 3-hour intervals over 24 h. The pellet characteristics, faecal and nutrient waste production were assessed. The control diet recorded a mean bulk density of 376.00 ± 5.19 g L−1 which was lower than the oilseed-based diets which ranged from 550.67 ± 3.06 g L−1 to 614.27 ± 2.08 g L−1. There was a positive correlation (p < 0.0001; r = 0.93) between the sinking rates of pellets and their bulk densities. The oilseed-based diets recorded 4–45% higher faecal matter production compared to the control diet. Fish fed Diet 3 had the lowest Total Ammonia-nitrogen (TAN) excretion rate of 106.14 ± 1.95 mg kg−1 while the control diet recorded the highest TAN excretion of 162.31 ± 4.39 mg kg−1. Accumulated dissolved phosphorus was 64.52–74.09% lower in the oilseed-based diets compared to the control.

Effectiveness of ecotechnologies in agriculture for the recovery and reuse of carbon and nutrients in the Baltic and boreo-temperate regions: a systematic map

BackgroundAgriculture is the main sector responsible for nutrient emissions in the Baltic Sea Region and there is a growing pressure to identify cost-effective solutions towards reducing nitrogen and phosphorus loads originating from farming activities. Recycling resources from agricultural waste is central to the idea of a circular economy, and has the potential to address the most urgent problems related to nutrients use in the food chain, such as depletion of natural phosphorus reserves, water pollution and waste management. This systematic map examined what evidence exists relating to the effectiveness of ecotechnologies in agriculture for the recovery and reuse of carbon and/or nutrients (nitrogen and phosphorus) in the Baltic Sea region and other comparable boreo-temperate systems.MethodsWe searched for both academic and grey literature. English language searches were performed in 5 bibliographic databases and search platforms, and Google Scholar. Searches in 36 specialist websites were performed in English, Finnish, Polish and Swedish. The searches were restricted to the period 2013 to 2017. Eligibility screening was conducted at two levels: title and abstract (screened concurrently for efficiency) and full text. Meta-data was extracted from eligible studies including bibliographic details, study location, ecotechnology name and description, type of outcome (i.e. recovered or reused carbon and/or nutrients), type of ecotechnology in terms of recovery source, and type of reuse (in terms of the end-product). Findings are presented here narratively and in a searchable database, and are also visualised in a web-based evidence atlas (an interactive geographical information system). In addition, knowledge gaps and clusters have been identified in the evidence base and described in detail.ResultsWe found 173 articles studying the effectiveness of 177 ecotechnologies. The majority of eligible articles were in English, originated from bibliographic databases and were published in 2016. Most studies with reported locations, and given our boreo-temperate scope, were conducted in Europe and North America. The three most prevalent ecotechnologies in the evidence base (collectively 40.7%) were; soil amendments, anaerobic digestion and (vermi)composting. Manure was the principal waste source used for recovery of nutrients or carbon, making up 55.4% of the all studies in evidence base, followed by a combination of manure and crop residues (22%). There were 51 studies with 14 ecotechnologies that reported on recovery of carbon and nutrients together, predominantly via (vermi)composting and anaerobic digestion. Only 27 studies focused on reuse of recovered nutrients and carbon through soil amendments.ConclusionsThis systematic map report provides an evidence base that can be useful for researchers and decision-makers in policy and practice working on transformation from linear to circular economy in the agricultural waste sector. Three potential topics for future systematic reviews are: (1) effectiveness of products recovered from different types of agricultural wastes as soil amendments or fertilizers; (2) effectiveness of anaerobic digestion as an ecotechnology used for recovery of nutrients and carbon; (3) effectiveness of composting and/or vermicomposting as ecotechnologies used for recovery of nutrients and carbon.

Toward a Regional Phosphorus (Re)cycle in the US Midwest.

Redirecting anthropogenic waste phosphorus (P) flows from receiving water bodies to high P demand agricultural fields requires a resource management approach that integrates biogeochemistry, agronomy, engineering, and economics. In the US Midwest, agricultural reuse of P recovered from spatially colocated waste streams stands to reduce point-source P discharges, meet agricultural P needs, and-depending on the speciation of recovered P-mitigate P losses from agriculture. However, the speciation of P recovered from waste streams via its chemical transformation-referred to here as recovered P (rP) differs markedly based on waste stream composition and recovery method, which can further interact with soil and crop characteristics of agricultural sinks. The solubility of rP presents key tensions between engineered P recovery and agronomic reuse because it defines both the ability to remove organic and inorganic P from aqueous streams and the crop availability of rP. The potential of rP generation and composition differs greatly among animal, municipal, and grain milling waste streams due to the aqueous speciation of P and presence of coprecipitants. Two example rP forms, phytin and struvite, engage in distinct biogeochemical processes on addition to soils that ultimately influence crop uptake and potential losses of rP. These processes also influence the fate of nitrogen (N) embodied in rP. The economics of rP generation and reuse will determine if and which rP are produced. Matching rP species to appropriate agricultural systems is critical to develop sustainable and financially viable regional exchanges of rP from wastewater treatment to agricultural end users.

Nitrogen and Phosphorus Waste Production from Different Fish Species Cultured at Floating Net Cages in Lake Maninjau, Indonesia

Nitrogen and Phosphorus Waste Production from Different Fish Species Cultured at Floating Net Cages in Lake Maninjau, Indonesia

Dietary available phosphorus requirement for on-growing gibel carp (Carassius auratus gibeliovar. CAS III)

A nine-week feeding experiment was conducted in flow-through system with gibel carp (43.8 +/- 0.2g) to study the effects of dietary available phosphorus (P) on growth, phosphorous digestibility and intestinal enzyme activities. Seven semipurified diets were formulated to contain 0.8 (the basal), 2.4, 3.6, 6.1, 7.4, 10.1 and 15.8g available phosphorus kg(-1) diet. The results showed that specific growth rate and feed efficiency increased with increasing dietary available P from 0.8 to 7.4g P kg(-1). Fish body ash increased with increasing dietary available P, while moisture, protein content or energy content had no difference. Total phosphorus waste discharging (TPW) increased with increased dietary phosphorous. Plasma glucose was higher in the fish fed with 7.4g kg(-1) P. Plasma triglycerides was lower in fish fed diets containing 6.1-10.1g kg(-1) P. No significant effects were observed in plasma P and Ca (p>.05). The activities of intestinal amylase, lipase and trypsin showed no difference, while AKP and Na+, K+-ATPase activities decreased with increasing dietary available P. In conclusion, based on the regression between specific growth rate (SGR), P retention efficiency, feed efficiency (FE) and dietary available P, the available P requirements for on-growing gibel carp were 10.69, 8.22 and 6.72g kg(-1), respectively.

Scenarios for achieving absolute reductions in phosphorus consumption in Singapore

Phosphorus is a resource that is utilized with efficiency in most parts of the world. Farmers fertilize with increasing precision; wastewater treatment plants strip phosphorus from sewage; and industries make use of phosphorus byproducts. Why, then, do incidents of eutrophication and harmful algal blooms related to excessive phosphorus outflows continue to intensify? Incremental improvements in phosphorus use efficiency and monitoring of individual phosphorus waste streams no longer seem sufficient to dampen these environmental impacts. A radical shift in perspective is needed, one in which phosphorus is treated as a resource rather than as waste. Using substance flow analysis, we explore various types of phosphorus management scenarios for a specific system, for the urban city-state of Singapore. These scenarios are jointly framed with the urban planning agency of Singapore and takes into consideration both behavioral and infrastructural changes to the status quo. These scenarios include strategies and technologies such as composting, separated incineration of organic and non-organic waste, anaerobic co-digestion of food waste and wastewater, and dedicated anaerobic digestion of food waste and wastewater. Publicly available UN Comtrade data is used to establish temporal trends in phosphorus consumption between 1989 and 2012. Phosphorus waste outputs are verified via empirically collected data on household and commercial waste generation. The results of this paper demonstrate how the transition from a linear to a closed-loop phosphorus cycle might be possible for Singapore, an island that is an important test bed for planning the sustainable metabolism of future urban areas.

Phosphorus in the Minnesota River Basin: The debate over its source and ways to mitigate impacts

Phosphorus in the Minnesota River Basin: The debate over its source and ways to mitigate impacts

A half-century of global phosphorus flows, stocks, production, consumption, recycling, and environmental impacts

Many contemporary aspects of the global phosphorus cycle have been evaluated over the last several years, but a comprehensive picture over time has not yet been provided. In this work, we generate a detailed quantitative picture of dynamic phosphorus stocks and flows, for both human and animal uses, from 1961 to 2013. During that half-century, total phosphorus consumption has increased fivefold, to 31 million metric tons (31Tg). However, losses and diversions from extraction to final consumption result in only about 22% of the extracted phosphorus being actually consumed as human food. Agricultural practices have changed as well, with on-farm wastes yielding to manufactured fertilizers as the primary source of phosphorus. Non-food uses such as detergents and metal coatings were about five times larger in 2013 than in 1961, though they currently account for only about a quarter of all phosphorus use. Waste phosphorus flows to water, dominated by agricultural operations in 1961, have now been overtaken by loss from phosphate rock mining. Overall, the phosphorus cycle shows a history of inefficiency and loss, but also many opportunities for improvements that could lead to a much more sustainable situation going forward.

Added Values of Time Series in Material Flow Analysis: The Austrian Phosphorus Budget from 1990 to 2011.

SummaryMaterial flow analysis is a tool that is increasingly used as a foundation for resource management and environmental protection. This tool is primarily applied in a static manner to individual years, ignoring the impact of time on the material budgets. In this study, a detailed multiyear model of the Austrian phosphorus budget covering the period 1990–2011 was built to investigate its behavior over time and test the hypothesis that a multiyear approach can also contribute to the improvement of static budgets. Further, a novel method was applied to investigate the quality and characteristics of the data and quantify the uncertainty. The degree of change between the budgets was assessed and showed that approximately half of the flows have changed significantly and, at times, abruptly since 1990, but it is not possible to distinguish unequivocally between constant and moderately changing flows given their uncertainty. The study reveals that the phosphorus transported in waste flows has increased more rapidly than its recovery, which accounted for 55% to 60% of the total waste phosphorus in 1990 and only 40% in 2011. The loss ratio in landfills and cement kilns has oscillated in the range of 40% to 50%. From a methodological point of view, the multiyear approach has broadened the conceptual model of the budget, making it more suitable as a basis for material accounting and monitoring. Moreover, the analysis of the data reconciliation process over a long period of time proved to be a useful tool for identifying systematic errors in the model.

Solidification/stabilization of lead‐contaminated soil using cement and waste phosphorus slag

Solidification/stabilization (S/S) is an effective technique for reducing the leachability of contaminants in soils. Very few studies have investigated the use of waste phosphorus slag (WPS) for S/S treatment of contaminated soils. Partial replacement of ordinary Portland cement (OPC) with WPS in the binder system is used to S/S of lead‐contaminated soil. Batch tests were conducted to study the physical properties of solidified forms with different concentrations of lead and WPS, namely unconfined compressive strength (UCS), setting times of early mixtures and changes in crystalline phases as well as chemical properties such as the leachability of lead and pH of the leachate. Results indicated that partial replacement of OPC with WPS could reduce the Pb leaching concentration of solidified samples effectively. XRD results indicated that the formation of fluoropyromorphite was strongly associated with the immobilization of lead. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 957–963, 2015