title: Remediation of Pulp and Paper Mill Biosolids using Vermiculture

authors: Shannon, Nicholas W.

subjects: Biosolids

abstract: Historical wastewater treatment systems at a New Zealand pulp and paper mill, resulted in a biosolid mass in the K-basin at Kinleith mill. Products extracted during the pulping process include resin acids, which are further transformed in the K-basin by microbial activity into recalcitrant end products retene and fichtelite. These products are toxic to fish due to bioaccumulation and subsequent endocrine disruption. Traditional methods for diverting these toxins from waterways were deposition into landfills and incineration, neither of which are considered environmentally sound. The aim of this study was to investigate the viability of vermicomposting as a method for bioremediation of recalcitrant resin acid derivatives from biosolids. Vermicomposting is a cost-effective option for not only reducing toxicity but also reducing biomass. It was hypothesised that earthworms can degrade organic extractives, principally resin acids and derivatives, through microbial, enzymatic, and oxidative mechanisms. A series of vermicomposting experiments were set up, to test the ability of Eisenia fetida (the tiger worm) to reduce both the amount of resin acids and overall biomass in a range of substrates. These included the original biosolid collected from K-basin, a  simulated  biosolid containing potting mix with and without additional extractive resins, as well as sterilised and unsterilised controls.  Five samples were taken from each experimental composter over 28 days and extracted into dichloromethane after removal of excess water followed by mechanical blending. Samples were concentrated and the amount of each extractive group was determined using gas chromatography mass spectroscopy. The overall biomass in each composter as well as the depurated earthworm mass was measured at the start and cessation of the experiment.  A slight reduction in biomass was observed in two out of the three substrates. This reduction was slightly enhanced by the presence of earthworms in the composter, however, it was not significant. The use of methyl bromide to sterilise the substrate was also not a significant factor in biomass reduction.  The overall weight of the earthworms decreased in all cases indicating the unsuitability of any of the substrates as a desirable food source. The addition of supplements such as yeast or manure to the biosolid composter may increase its appeal.
There was a significant reduction in extractive content in all substrates over the 28 day period however no significant difference attributable to the presence or absence of worms was observed.  It was hypothesised that the rigorous sampling process encouraged oxidative breakdown of the extractives due to increased exposure to both air and light. This was evident when the extractive content of K-basin measured in 1993 was compared to the samples used in this study collected in 2006.
Whilst vermicomposting does not appear to be an effective treatment for removing resin acids from biosolid mass, the sampling processes used in this study highlighted the effect that rigorous stirring and increased exposure to air and light can have on the natural breakdown of these products. An effective treatment for the removal of resin acids from K-basin may be as simple as regular ploughing.

text: Remediation of Pulp and Paper Mill Biosolids using Vermiculture Historical wastewater treatment systems at a New Zealand pulp and paper mill, resulted in a biosolid mass in the K-basin at Kinleith mill. Products extracted during the pulping process include resin acids, which are further transformed in the K-basin by microbial activity into recalcitrant end products retene and fichtelite. These products are toxic to fish due to bioaccumulation and subsequent endocrine disruption. Traditional methods for diverting these toxins from waterways were deposition into landfills and incineration, neither of which are considered environmentally sound. The aim of this study was to investigate the viability of vermicomposting as a method for bioremediation of recalcitrant resin acid derivatives from biosolids. Vermicomposting is a cost-effective option for not only reducing toxicity but also reducing biomass. It was hypothesised that earthworms can degrade organic extractives, principally resin acids and derivatives, through microbial, enzymatic, and oxidative mechanisms. A series of vermicomposting experiments were set up, to test the ability of Eisenia fetida (the tiger worm) to reduce both the amount of resin acids and overall biomass in a range of substrates. These included the original biosolid collected from K-basin, a  simulated  biosolid containing potting mix with and without additional extractive resins, as well as sterilised and unsterilised controls.  Five samples were taken from each experimental composter over 28 days and extracted into dichloromethane after removal of excess water followed by mechanical blending. Samples were concentrated and the amount of each extractive group was determined using gas chromatography mass spectroscopy. The overall biomass in each composter as well as the depurated earthworm mass was measured at the start and cessation of the experiment.  A slight reduction in biomass was observed in two out of the three substrates. This reduction was slightly enhanced by the presence of earthworms in the composter, however, it was not significant. The use of methyl bromide to sterilise the substrate was also not a significant factor in biomass reduction.  The overall weight of the earthworms decreased in all cases indicating the unsuitability of any of the substrates as a desirable food source. The addition of supplements such as yeast or manure to the biosolid composter may increase its appeal.
There was a significant reduction in extractive content in all substrates over the 28 day period however no significant difference attributable to the presence or absence of worms was observed.  It was hypothesised that the rigorous sampling process encouraged oxidative breakdown of the extractives due to increased exposure to both air and light. This was evident when the extractive content of K-basin measured in 1993 was compared to the samples used in this study collected in 2006.
Whilst vermicomposting does not appear to be an effective treatment for removing resin acids from biosolid mass, the sampling processes used in this study highlighted the effect that rigorous stirring and increased exposure to air and light can have on the natural breakdown of these products. An effective treatment for the removal of resin acids from K-basin may be as simple as regular ploughing.

year: 2009

title: Connecting with tephras: principles, functioning, and applications of tephrochronology in Quaternary science

authors: Lowe, David J.

abstract: Tephrochronology is a unique method for linking and dating geological, palaeoecological, palaeoclimatic, or archaeological sequences or events. The method relies firstly on stratigraphy and the law of superposition, which apply in any study that connects or correlates deposits from one place to another. Secondly, it relies on characterising and hence identifying or ‘fingerprinting’ tephra layers using either physical properties evident in the field or those obtained from laboratory analysis, including mineralogical examination by optical microscopy or geochemical analysis of glass shards or crystals (e.g., Fe-Ti oxides, ferromagnesian minerals) using the electron microprobe and other tools. Thirdly, the method is enhanced when a numerical age is obtained for a tephra layer by (1) radiometric methods such as radiocarbon, fission-track, U-series, or Ar/Ar dating, (2) incremental dating methods including dendrochronology or varved sediments or layering in ice cores, or (3) age-equivalent methods such as palaeomagnetism or correlation with marine oxygen isotope stages or palynostratigraphy. Once known, that age can be transferred from one site to the next using stratigraphic methods and by matching compositional characteristics, i.e., comparing ‘fingerprints’ from each layer. Used this way, tephrochronology is an age-equivalent dating method.

text: Connecting with tephras: principles, functioning, and applications of tephrochronology in Quaternary science Tephrochronology is a unique method for linking and dating geological, palaeoecological, palaeoclimatic, or archaeological sequences or events. The method relies firstly on stratigraphy and the law of superposition, which apply in any study that connects or correlates deposits from one place to another. Secondly, it relies on characterising and hence identifying or ‘fingerprinting’ tephra layers using either physical properties evident in the field or those obtained from laboratory analysis, including mineralogical examination by optical microscopy or geochemical analysis of glass shards or crystals (e.g., Fe-Ti oxides, ferromagnesian minerals) using the electron microprobe and other tools. Thirdly, the method is enhanced when a numerical age is obtained for a tephra layer by (1) radiometric methods such as radiocarbon, fission-track, U-series, or Ar/Ar dating, (2) incremental dating methods including dendrochronology or varved sediments or layering in ice cores, or (3) age-equivalent methods such as palaeomagnetism or correlation with marine oxygen isotope stages or palynostratigraphy. Once known, that age can be transferred from one site to the next using stratigraphic methods and by matching compositional characteristics, i.e., comparing ‘fingerprints’ from each layer. Used this way, tephrochronology is an age-equivalent dating method.

year: 2013

title: Whānau mentoring, Māori youth and crime

authors: Joseph, Robert

abstract: This article will discuss how the whänau was the traditional institution for teaching and nurturing children through (among other things) effective mentoring, and how children were taught tikanga, or the ‘right way’ to think, speak, act and become. Traditional leadership development, whänau dysfunction and whänau renewal are also discussed, followed by my conclusions. This article will not be discussing the place of colonisation, high unemployment, lower education rates and other socio-economic disparities among Mäori that play a part in the causes and perpetuation of Mäori youth and crime. A discussion on the Treaty of Waitangi, indigenous rights, and Mäori development is also omitted although the importance of each of these areas is acknowledged. As the theme of this issue of Childrenz Issues is ‘seeking pathways beyond colonisation’, the focus of this article is on Mäori dealing appropriately with the problems of Mäori youth and crime through effective mentoring within the institution of the whänau.

text: Whānau mentoring, Māori youth and crime This article will discuss how the whänau was the traditional institution for teaching and nurturing children through (among other things) effective mentoring, and how children were taught tikanga, or the ‘right way’ to think, speak, act and become. Traditional leadership development, whänau dysfunction and whänau renewal are also discussed, followed by my conclusions. This article will not be discussing the place of colonisation, high unemployment, lower education rates and other socio-economic disparities among Mäori that play a part in the causes and perpetuation of Mäori youth and crime. A discussion on the Treaty of Waitangi, indigenous rights, and Mäori development is also omitted although the importance of each of these areas is acknowledged. As the theme of this issue of Childrenz Issues is ‘seeking pathways beyond colonisation’, the focus of this article is on Mäori dealing appropriately with the problems of Mäori youth and crime through effective mentoring within the institution of the whänau.

year: 2007-01