title: Protein-Intercalated Bentonite for Bio-composites

authors: Shamsuddin, Rashid

subjects: Biocomposites

abstract: The application of clays in various fields such as agriculture, mining, construction, petroleum derivatives recovery, waste water treatment and material reinforcements is closely related to their unique properties including small particle size with high surface negativity and hydrophilic nature. This work investigated the potential use of bentonite clay for treatment of meat rendering waste water by adsorption and utilizing the spent bentonite for bioplastic fillers. Models were applied to predict the organic adsorption and the sedimentation of clay particles in solution.

Various clays including bentonite are typically used in polymers to enhance composite properties at a very low level of loading. As bio-composite fillers, bentonite is modified with organics such as alkylammonium, amines and gelatin to improve compatibility with the matrix polymer. The use of these materials can be expensive and therefore, more attention has been directed to using waste sources such as meat processing waste. One type of waste, stickwater which contains approximately 4-5 % protein, 1-2 % fat and < 1 % minerals, could become a low-cost organic modifier for bentonite. Stickwater has a biological oxygen demand (BOD) of 150 000 mg/L, coloured, odorous and its treatment can be expensive.

Currently, stickwater is mostly dried and added to blood and bone meal in meat rendering plants. Where no further unit operations are carried out on stickwater, the stickwater must be treated to reduce the BOD. Depending on the scale of operation, a plant can produce up to 30 000 L of stickwater at 2-5 % solids per day. Waste water treatment costs NZ$ 0.90 per kg solids or approximately NZ$ 1350 per day. The main protein in stickwater is gelatin, a denatured form of collagen. Extracting protein from stickwater by adsorption can reduce the treatment charges by decreasing the BOD as well as producing organically-modified bentonite for use as a bio-composite filler.

Gelatin has a large numbers of side groups and can be easily crosslinked and adsorbed. Locally mined bentonite in the form of calcium and sodium bentonite, CaBt and NaBt respectively, costs NZ$ 20 per tonne and has a high gelatin adsorption capacity of up to 405 mg protein per gram bentonite (mg/g). For 30 000 kg stickwater, treatment using sodium bentonite costs around NZ$ 74 per day (this excludes operating and other material costs). Gelatin adsorption from stickwater gave a lower adsorption capacity of 246 mg/g due to competition between mineral and fat solutes with gelatin for binding sites on the adsorbent. Adsorption of solutes by bentonite occurred on the surface and within the interlayer spacings as revealed by X-ray diffraction (XRD) and thermogravimetric analysis (TGA).

Settling or sedimentation of particles from solution was studied to find an alternative to centrifugation for solid recovery after treatment. At 2 % protein concentration, settling was obtained for CaBt in gelatin at pH 3 whereas in stickwater, both CaBt and NaBt settled at pH 3. The highest clay recovery was obtained after overnight settling at 91 and 95 % for CaBt in gelatin and stickwater at pH 3. Conditions that favoured settling corresponded to low gelatin adsorption.

Bentonite consists of aluminosilicate layers and upon organic adsorption, intercalation and exfoliation can be achieved. As reinforcement materials, this leads to fillers with a very high aspect ratio in matrix polymers such as in bloodmeal-based plastic, also known as Novatein Thermoplastic Protein or NTP. In NTP, the highest improvement in tensile strength and Young’s modulus was at 23 % (11.45 MPa) and 17 % (727.45 MPa) at 0.5 parts stickwater-modified NaBt per hundred of bloodmeal (pphBM). For elongation at break, the highest increase of 23.5 % was achieved for unmodified NaBt at 0.5 pphBM. These improvements also correspond with enhancements in glass transition temperature (Tg) of composites and increased basal spacing (d-value) of bentonite. Transmission electron microscope (TEM) analysis confirmed the exfoliation of fillers for organically-modified bentonite. These observations, particularly at low filler dosage strongly suggest the formation of nanocomposites.

text: Protein-Intercalated Bentonite for Bio-composites The application of clays in various fields such as agriculture, mining, construction, petroleum derivatives recovery, waste water treatment and material reinforcements is closely related to their unique properties including small particle size with high surface negativity and hydrophilic nature. This work investigated the potential use of bentonite clay for treatment of meat rendering waste water by adsorption and utilizing the spent bentonite for bioplastic fillers. Models were applied to predict the organic adsorption and the sedimentation of clay particles in solution.

Various clays including bentonite are typically used in polymers to enhance composite properties at a very low level of loading. As bio-composite fillers, bentonite is modified with organics such as alkylammonium, amines and gelatin to improve compatibility with the matrix polymer. The use of these materials can be expensive and therefore, more attention has been directed to using waste sources such as meat processing waste. One type of waste, stickwater which contains approximately 4-5 % protein, 1-2 % fat and < 1 % minerals, could become a low-cost organic modifier for bentonite. Stickwater has a biological oxygen demand (BOD) of 150 000 mg/L, coloured, odorous and its treatment can be expensive.

Currently, stickwater is mostly dried and added to blood and bone meal in meat rendering plants. Where no further unit operations are carried out on stickwater, the stickwater must be treated to reduce the BOD. Depending on the scale of operation, a plant can produce up to 30 000 L of stickwater at 2-5 % solids per day. Waste water treatment costs NZ$ 0.90 per kg solids or approximately NZ$ 1350 per day. The main protein in stickwater is gelatin, a denatured form of collagen. Extracting protein from stickwater by adsorption can reduce the treatment charges by decreasing the BOD as well as producing organically-modified bentonite for use as a bio-composite filler.

Gelatin has a large numbers of side groups and can be easily crosslinked and adsorbed. Locally mined bentonite in the form of calcium and sodium bentonite, CaBt and NaBt respectively, costs NZ$ 20 per tonne and has a high gelatin adsorption capacity of up to 405 mg protein per gram bentonite (mg/g). For 30 000 kg stickwater, treatment using sodium bentonite costs around NZ$ 74 per day (this excludes operating and other material costs). Gelatin adsorption from stickwater gave a lower adsorption capacity of 246 mg/g due to competition between mineral and fat solutes with gelatin for binding sites on the adsorbent. Adsorption of solutes by bentonite occurred on the surface and within the interlayer spacings as revealed by X-ray diffraction (XRD) and thermogravimetric analysis (TGA).

Settling or sedimentation of particles from solution was studied to find an alternative to centrifugation for solid recovery after treatment. At 2 % protein concentration, settling was obtained for CaBt in gelatin at pH 3 whereas in stickwater, both CaBt and NaBt settled at pH 3. The highest clay recovery was obtained after overnight settling at 91 and 95 % for CaBt in gelatin and stickwater at pH 3. Conditions that favoured settling corresponded to low gelatin adsorption.

Bentonite consists of aluminosilicate layers and upon organic adsorption, intercalation and exfoliation can be achieved. As reinforcement materials, this leads to fillers with a very high aspect ratio in matrix polymers such as in bloodmeal-based plastic, also known as Novatein Thermoplastic Protein or NTP. In NTP, the highest improvement in tensile strength and Young’s modulus was at 23 % (11.45 MPa) and 17 % (727.45 MPa) at 0.5 parts stickwater-modified NaBt per hundred of bloodmeal (pphBM). For elongation at break, the highest increase of 23.5 % was achieved for unmodified NaBt at 0.5 pphBM. These improvements also correspond with enhancements in glass transition temperature (Tg) of composites and increased basal spacing (d-value) of bentonite. Transmission electron microscope (TEM) analysis confirmed the exfoliation of fillers for organically-modified bentonite. These observations, particularly at low filler dosage strongly suggest the formation of nanocomposites.

year: 2013

title: Pollution in the Te Aroha district caused by mining

authors: Hart, Philip

abstract: Whereas miners (and their supporters in the Mines Department) felt constrained by the imposition of environmental controls, many Te Aroha residents were concerned about the purity of their domestic water supply, although a vocal minority was more interested in the possibilities of jobs and money. As mullock and tailings were unavoidable consequences of mining, when farmers had fine silt deposited on their land they combined with town-dwellers to seek the removal of the designation of the Waihou River as a sludge channel.
Efforts to revive mining during the depression of the 1930s revived concerns about pollution, and in the following decade the Auckland Smelting Company’s efforts to develop the Tui portion of the field provoked considerable debate about protecting Te Aroha’s water supply amongst officials and within the community. The warden, encouraged by departmental officials, permitted mining, but imposed conditions that its opponents considered to be inadequate and which the company sought to evade.

text: Pollution in the Te Aroha district caused by mining Whereas miners (and their supporters in the Mines Department) felt constrained by the imposition of environmental controls, many Te Aroha residents were concerned about the purity of their domestic water supply, although a vocal minority was more interested in the possibilities of jobs and money. As mullock and tailings were unavoidable consequences of mining, when farmers had fine silt deposited on their land they combined with town-dwellers to seek the removal of the designation of the Waihou River as a sludge channel.
Efforts to revive mining during the depression of the 1930s revived concerns about pollution, and in the following decade the Auckland Smelting Company’s efforts to develop the Tui portion of the field provoked considerable debate about protecting Te Aroha’s water supply amongst officials and within the community. The warden, encouraged by departmental officials, permitted mining, but imposed conditions that its opponents considered to be inadequate and which the company sought to evade.

year: 2016

title: Restructuring and hospital care: Sub-national trends, differentials, and their impacts; New Zealand from 1981

authors: Pool, Ian

abstract: An analysis of the "nation's health" is the central concern of this study. Its genesis was a detailed, technical, time-series research on regional and ethnic differentials in health in New Zealand. But as this work progressed it became increasingly evident that the results of this more narrow analysis could make a wider contribution to the development of a knowledge-base on health trends and on the impacts of policy on these. In a sense, the analysis provides a demographic audit of health trends over the last two decades.
The focus here is different from that in most other studies on restructuring of the New Zealand health system as their concern was either to review in detail the rewriting of policy per se, and attendant structural and institutional changes (Fougere 2001), or to identify how these changes relate to changes in mortality (Blakely et al. 2008). The research question reported here was, instead, to analyse the most crucial of health outcomes, „how long we live and how often we end up in hospital‟, identified in the earlier quotation, to report patterns and trends in hospital use nationally and sub-nationally over the period under review, and to determine the degrees to which various sub-populations benefited, or did not benefit, from these changes. The analysis focuses on the hospital sector in the system, but it will also show relations between this and other sectors, formal (e.g. primary health) and less formal (notably the healthcare afforded sickness and invalid beneficiaries). Thus two questions are addressed:
1. whether or not the nation‟s population health improved over the period and;
2. whether or not there was a convergence in patterns of health gain across its constituent sub-populations defined geographically and ethnically.
This monograph deals with sub-national differences in health in New Zealand over a period of substantial socio-economic restructuring and associated radical changes in health policy, health systems and their related information systems (see also, Text Appendix A). It complements the recently published analysis of national ethnic trends in mortality (Blakely et al. 2004), but differs in several critical respects. That study reviewed health status by emphasising aetiologies and causes of death. In contrast, the present analysis focuses on actuarial dimensions of both mortality and morbidity and on health as measured by functional capacity rather than the disease orientated „burden of disease‟. It goes beyond health status issues to look at the system itself, to assess whether health policy outcomes were generated more through efficiency-gain (economic or service delivery, such as those resulting in a convergence sub-nationally of supply and demand effects), or through health gains, or ideally, by both.
To do this, and as a by-product to analyse changes in health status and the system in an era of restructuring, innovative methodologies and composite time-series indices combining the two dimensions of a „nation‟s health‟, needing hospital care and longevity, have had to be custom-designed. To achieve this objective, the ensuing analysis is often technical, and may introduce concepts that are unfamiliar to some readers. In order to look at possible inequalities of outcome, comparisons were made between regions and ethnic groups, as well as age-groups and genders, and as a result, in places the analysis becomes rather complex.

text: Restructuring and hospital care: Sub-national trends, differentials, and their impacts; New Zealand from 1981 An analysis of the "nation's health" is the central concern of this study. Its genesis was a detailed, technical, time-series research on regional and ethnic differentials in health in New Zealand. But as this work progressed it became increasingly evident that the results of this more narrow analysis could make a wider contribution to the development of a knowledge-base on health trends and on the impacts of policy on these. In a sense, the analysis provides a demographic audit of health trends over the last two decades.
The focus here is different from that in most other studies on restructuring of the New Zealand health system as their concern was either to review in detail the rewriting of policy per se, and attendant structural and institutional changes (Fougere 2001), or to identify how these changes relate to changes in mortality (Blakely et al. 2008). The research question reported here was, instead, to analyse the most crucial of health outcomes, „how long we live and how often we end up in hospital‟, identified in the earlier quotation, to report patterns and trends in hospital use nationally and sub-nationally over the period under review, and to determine the degrees to which various sub-populations benefited, or did not benefit, from these changes. The analysis focuses on the hospital sector in the system, but it will also show relations between this and other sectors, formal (e.g. primary health) and less formal (notably the healthcare afforded sickness and invalid beneficiaries). Thus two questions are addressed:
1. whether or not the nation‟s population health improved over the period and;
2. whether or not there was a convergence in patterns of health gain across its constituent sub-populations defined geographically and ethnically.
This monograph deals with sub-national differences in health in New Zealand over a period of substantial socio-economic restructuring and associated radical changes in health policy, health systems and their related information systems (see also, Text Appendix A). It complements the recently published analysis of national ethnic trends in mortality (Blakely et al. 2004), but differs in several critical respects. That study reviewed health status by emphasising aetiologies and causes of death. In contrast, the present analysis focuses on actuarial dimensions of both mortality and morbidity and on health as measured by functional capacity rather than the disease orientated „burden of disease‟. It goes beyond health status issues to look at the system itself, to assess whether health policy outcomes were generated more through efficiency-gain (economic or service delivery, such as those resulting in a convergence sub-nationally of supply and demand effects), or through health gains, or ideally, by both.
To do this, and as a by-product to analyse changes in health status and the system in an era of restructuring, innovative methodologies and composite time-series indices combining the two dimensions of a „nation‟s health‟, needing hospital care and longevity, have had to be custom-designed. To achieve this objective, the ensuing analysis is often technical, and may introduce concepts that are unfamiliar to some readers. In order to look at possible inequalities of outcome, comparisons were made between regions and ethnic groups, as well as age-groups and genders, and as a result, in places the analysis becomes rather complex.

year: 2009