Technologies for pollutant removal and resource recovery from blackwater: a review

● Blackwater is the main source of organics and nutrients in domestic wastewater. ● Various treatment methods can be applied for resource recovery from blackwater. ● Blackwater treatment systems of high integration and efficiency are the future trend. ● More research is needed for the practical use of blackwater treatment systems. Blackwater (BW), consisting of feces, urine, flushing water and toilet paper, makes up an important portion of domestic wastewater. The improper disposal of BW may lead to environmental pollution and disease transmission, threatening the sustainable development of the world. Rich in nutrients and organic matter, BW could be treated for resource recovery and reuse through various approaches. Aimed at providing guidance for the future development of BW treatment and resource recovery, this paper presented a literature review of BWs produced in different countries and types of toilets, including their physiochemical characteristics, and current treatment and resource recovery strategies. The degradation and utilization of carbon (C), nitrogen (N) and phosphorus (P) within BW are underlined. The performance of different systems was classified and summarized. Among all the treating systems, biological and ecological systems have been long and widely applied for BW treatment, showing their universality and operability in nutrients and energy recovery, but they are either slow or ineffective in removal of some refractory pollutants. Novel processes, especially advanced oxidation processes (AOPs), are becoming increasingly extensively studied in BW treatment because of their high efficiency, especially for the removal of micropollutants and pathogens. This review could serve as an instructive guidance for the design and optimization of BW treatment technologies, aiming to help in the fulfilment of sustainable human excreta management.     

NLRP3 inflammasome is involved in the mechanism of mitigative effect of selenium on lead-induced inflammatory damage in chicken kidneys

Environmental Science and Pollution Research - Lead (Pb) is a kind of widespread toxic environmental pollutant which can cause harm to organisms. Selenium (Se) has the property of mitigating Pb...     

Recovery of iron oxide and calcium chloride from an iron-rich chloride waste using calcium carbonate

Journal of Material Cycles and Waste Management - The ilmenite-chloride process has used for the production of TiCl4 from the ilmenite (FeTiO3) ore, which produces cyclone dust containing mostly...     

Synthesis of tributyl citrate using acid ionic liquid as catalyst

Synthesis of tributyl citrate (TBC) has been studied by using acid functionalized ionic liquid as catalyst. The results indicated that acidic ionic liquids show good catalytic and reusable performance. Under the optimum conditions, using 1-methyl-3-(3-sulfopropyl)-imidazolium hydrogen sulfate as catalyst, the conversion of citric acid was 97%. After easily separated from the products the ionic liquid could be reused 13 times without any disposal, and the conversion of citric acid was not less than 93%. Therefore, an environmental friendly approach for the synthesis of tributyl citrate is provided.     

The drivers for contractors’ green innovation: an industry perspective

In the construction industry, contractors have been facing the challenge to meet the emerging needs related to the reduction of environmental impacts during the construction process. Generally, the commitment of efforts and resources from contractors to meet these needs is motivated by the influence exerted from environmental regulations and stakeholder demands. However, managerial environmental concerns and size of firms also account as key factors affecting the adoption of green construction practices. Therefore, the aim of this research is to identify those factors influencing contractors to adopt green construction practices by using data gathered from a survey. From the results, it has been found that managerial concern is the most important driver for the adoption of green practices. Significant relationships have also been found between government regulations and business size with the adoption of green construction practices. However, there is no significant evidence on the relationship among the adoption of green construction practices with perceived stakeholders’ pressures. The findings from this study are significant in the understanding on the factors of green construction management. This knowledge may contribute to better decision-making towards implementing green construction practices.     

Responses of plant functional groups to natural nitrogen fertility on an alpine grassland in the Qinghai-Tibet plateau

Species distribution is often closely associated with soil nutrients in terrestrial ecosystem. In contrast to most manipulated N (nitrogen) experimental studies, there are few observation experiments examining the distribution of species or functional groups along a natural soil N gradient. Alpine meadows with higher soil spatial heterogeneity at fine scale, which have a large gradient in soil N gradient, provides an ideal system to examine the distribution of species or functional groups. Here we used redundancy analysis (RDA) to examine the relationships between soil and plant properties in northeast of Qinghai-Tibet Plateau over two years. The results showed the relative biomass of forbs increased, while those of legumes and grasses decreased with the soil N availability. This suggests that legumes and grasses had stronger tolerance to infertile soils than forbs, which may due to the N₂-fixed for legumes and high nutrient use efficiency for grasses. Furthermore, the positive significant relationships between the percentage of legumes biomass and N: P (phosphorus) ratio were found in the whole community and non-legumes, confirming the presence of legumes improved the vegetation N status even for non-legumes.     

Iodine-129 and plutonium isotopes in Arctic kelp as historical indicators of transport of nuclear fuel-reprocessing wastes from mid-to-high latitudes in the Atlantic Ocean

Iodine-129:iodine-127 ratios were determined using accelerator mass spectrometry in 34 Arctic marine algae collected between 1930 and 1993. A smaller set (5) of marine algae were also analyzed mass spectrometrically to determine plutonium-isotope ratios. The ¹²⁹I:¹²⁷I ratio increased as much as three orders of magnitude from a mean of <1×10⁻¹¹ (atom/atom) in the pre-nuclear era (before 1945) to nearly 1000×10⁻¹¹ in 1993 for marine algae collected from the Novaya Zemlya archipelago separating the Barents and Kara Seas. The predominant basis for the higher ratios in the Novaya Zemlya kelps appears to be upcurrent sources of ¹²⁹I from nuclear fuel-reprocessing facilities at Sellafield (UK) and La Hague (France). Relatively high ²⁴¹Pu:²³⁹Pu ratios (compared to observed bomb fallout at boreal latitudes, decay corrected to the date of collection) also corroborate the influence of non-fallout sources. The small size of the data set precludes determining if there are significant contributions of ¹²⁹I and other radionuclides from Russian sources. In contrast, marine algae collected between 1969 and 1993 in the Bering, Beaufort and East Siberian Seas had much lower ¹²⁹I:¹²⁷I ratios (mean=14.04×10⁻¹¹±3.15 SD) than those observed in the European Arctic. The narrow range of ratios in Ameriasian Arctic kelps, and the modest change over that time period, indicate that there were no major contributions of non-fallout ¹²⁹I to North American Arctic surface waters at the time that the algae were collected. The potential for timing the transport of fuel-reprocessed ¹²⁹I through analysis of additional archived samples is outlined. Received: 10 November 1997 / Accepted: 24 February 1998     

Treatment of mature landfill leachate by biofilters and Fenton oxidation

A series of processes by biofilter and Fenton oxidation to treat mature landfill leachate has been devised. At a hydraulic loading rate of 20 l m^?3 d^?1, a biofilter packed with aged refuse is found to remove 80% of chemical oxygen demand (COD), 89% of ammonia nitrogen and 96% of total phosphorus (TP). Particularly, TP levels dropped below 1 mg l^?1. The optimal condition for Fenton oxidation was selected to be an initial pH of 5, a dosage of 0.01 and 0.02 mol l^?1 of FeSO₄ and H₂O₂, respectively, and a duration of 3 h, where COD removal efficiency reaches 58.6%, and BOD₅/COD ratio is raised from 0.05 to 0.20. Subsequent treatment by a biofilter packed with slag reduces COD, ammonia nitrogen levels to less than 100, 25 mg l^?1, respectively. A pilot scale experiment conducted in situ demonstrates that this series of processes exhibits a high efficiency in removing pollutants from mature landfill leachate and it is viable for application.