Wood Pulp Paper Research Articles

Evaluation of the antioxidant potential for three essential oils on the properties of wood pulp paper

Purpose This study aims to determine the efficiency of three types of essential oils (EOs) as antioxidants on wood pulp paper samples: camphor oil, clove oil and lavender oil. Because of the detrimental influence of the oxidation process on wood pulp paper, this type of paper suffers significant disintegration. Design/methodology/approach The evaluation methodology is based on scanning electron microscope and three directions laser microscope, the hydrogen ion concentration measurement, color change measurement using the CIELAB system and infrared spectrum analysis, as well as investigating the mechanical properties of paper as represented by tensile and elongation to determine Young’s modulus values. Findings According to the findings, camphor was an effective antioxidant for paper samples, protecting them from the damaging effects of oxidation and the impact of artificial aging processes while also improving the mechanical properties of paper. Originality/value This paper emphasizes the concept of using environmentally friendly materials derived from EOs, owing to their ease of application, lack of environmental impact, distinctive properties, low cost and distinctive properties in both curative and preventive conservation of paper manuscripts.

Preparation of PBT@PP-CNC@cellulose wood pulp paper double-layers fuel filtration materials with high efficiency and high dust holding capacity

Preparation of PBT@PP-CNC@cellulose wood pulp paper double-layers fuel filtration materials with high efficiency and high dust holding capacity

Direct utilization of cationic cellulose nanoparticles derived from maize-stalk parenchyma for intensifying mechanical properties and antibacterial activity in non-refined pulp paper

In recent years, an increasing focus has been placed on the mitigation of carbon dioxide emissions, underscoring the significance of the sustainable energy-conservation industry as a prominent and consequential field of development. As an energy-intensive procedure within the papermaking sector, the process of pulp-fiber beating necessitates an imperative exploration of alternative approaches aimed at mitigating energy consumption. This study has synthesized renewable cationic cellulose nanoparticles (CCNPs) extracted from the parenchymal cells of maize stalk pith. The objective is to demonstrate their viability as a reinforcing additive for paper sheets, thereby reducing the reliance on conventional beating processes. The results showed that CCNPs were prone to augment the physical strength of bleached papers, compared with unbleached papers. The inclusion of 9% CCNPs led to a remarkable 163.5% and 140.0% increase in tear and tensile indexes for bleached Eucalyptus paper, respectively. Incorporating CCNPs into non-refined paper yields physical traits akin to wood pulp paper beaten over 40 °SR. The CCNP-strengthened handsheets exhibited superior tensile and tear index in comparison to commercial dry strength additives such as cationic starch (CS) and cationic polyacrylamide (CPAM). Additionally, at 80 μg/ml concentration, E-B-9 displayed significant bactericidal effectiveness, achieving an impressive 97% reduction in Escherichia coli. This notable outcome is attributed to the presence of quaternary ammonium salt moieties in the formulation. This investigation introduces a promising approach where in the utilization of CCNP as an innovative multifunctional agent for paper holds the potential to enhance paper performance and concurrently reduce production costs.

Profiling of historical rag papers by their non-cellulosic polysaccharide composition

Hemicellulose and pectin are noteworthy components of historical European rag papers, and have not been studied in detail so far. Rag papers were made from used textiles, and fiber-based utilities, such as ropes and bags. These had been prepared until the mid-19th century from plant-based fibers. Their polysaccharide composition could relate to their condition and history. This information can be expected to hold importance for the preservation and conservation of historical objects.We investigated a collection of rag papers of different age for their composition of non-cellulosic polysaccharides, and compared the findings with modern rag papers and wood pulps. Furthermore, a non-destructive determination of the hemicellulose and pectin content by near-infrared spectroscopy was developed.Historical rag papers had a lower hemicellulose/pectin content than pulps; the fractions of rhamnose, galactose, and arabinose were higher, while xylose was lower. In modern rag papers, xylose tended to be at the higher end of the range, which suggests a degradation of hemicelluloses/pectin over time or a change in raw materials and manufacturing. Rag papers also showed higher crystallinity than wood pulp papers. These findings provide insights into rag paper characteristics and offer potential classification methods.

A highly efficient, colorless phosphorus–nitrogen synergistic flame retardant for durable flame retardancy in wood pulp paper

Wood pulp paper (WPP) is an exemplary substrate material, yet its flammability impedes the widespread application in diverse functional fields. Herein, a highly effective, colorless and transparent phosphorus–nitrogen flame retardant, namely ammonium salt of tris(hydroxymethyl)aminomethane diphosphonic acid (AMPAP-NH4+) without halogen and formaldehyde, has been synthesized for WPP. Chemical grafting was employed to confer highly durable flame retardancy to the WPP, enabling it to maintain excellent fire resistance after functionalization. X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy (EDS) analysis demonstrated that AMPAP-NH4+ was directly linked to cellulose fibers via POC bonds, effectively introducing P and N elements into the WPP without altering the surface morphology of the fibers. Results from thermogravimetric analysis, vertical burning test, limiting oxygen index test, cone calorimeter test and thermogravimetric-Fourier infrared spectrometer test demonstrated that the treated WPP exhibited outstanding flame retardancy. The peak heat release rate (pHRR) and total heat release (THR) values decreased by 80.8% and 70.9%, respectively, and the limiting oxygen index (LOI) increased to 41.4%. Furthermore, due to the stability of the POC bond, the treated samples remained unignited after 168 h, with a high LOI value of 35.3%. In summary, AMPAP-NH4+ serves as a phosphorus–nitrogen synergistic transparent flame retardant that can effectively and durably impart paper with flame retardancy without altering its surface morphology.

Fabrication of fully degradable branched poly (lactic acid) nanofiber membranes for high‐efficiency filter paper materials

AbstractAir pollution caused by particulate matter (PM) poses an imminent threat to the global environment and public health. However, balancing the removal efficiency and pressure drop of most filter materials is difficult. Moreover, filter materials are non‐degradable and non‐recyclable, causing serious harm to the environment. Herein, a strategy to create fully degradable branched poly (lactic acid) (PLA) nanofibers based on electrospinning by adjusting the spinning solution properties was reported and branched PLA nanofibers were applied as nanofiber filter paper for air filtration materials. When the PLA and tetrabutylammonium chloride concentrations were 8 and 5 wt%, respectively, PLA nanofibers with branched structures were obtained. The obtained nanofibers possessed a small pore size (0.70 μm), high porosity (92.3%), appropriate mechanical properties, resulting in high PM0.3 removal efficiency (99.95%), low air resistance (79.67 Pa), and promising long‐term PM2.5 purification. Notably, branched T‐PLA‐5 nanofibers exhibited excellent filtration performance when applied to cellulose wood pulp paper. The filtration efficiency of the nanofiber filter paper remained stable above 85% for PM0.3 (32 L min−1) after 5000 backflushings. Thus, the preparation of such nanomaterials may provide new insights into the design and development of high‐performance degradable filtration materials for various applications.

Application of Advanced Analytical Techniques in Organic Cultural Heritage: A Case Study of Ancient Architecture Relics in the Palace Museum (Beijing)

Multilayer objects with different interfaces are quite typical for architectural heritage, and from them may be inferred the age, production process, and deterioration mechanism through analyzing characteristic compositions with advanced analytical techniques. The Meiwu ceiling in the Hall of Mental Cultivation of the Palace Museum was found to contain many paper-based layers during conservation. Once several surface strata were detached, a colorful layer of printed fabric textile was discovered integrally. Through microscopic observation and micro-attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) imaging, the overall structure consisted of 11 layers, namely, bast paper, cotton wiring, xuan paper, cotton printed fabric, two yellow board papers, bamboo paper, three wood pulp paper and surface coatings, and starch was considered as an organic adhesive. For identification of the printed fabric’s color palette, ultra-performance liquid chromatography (UPLC) combined with high-resolution quadrupole time-of-flight (QTOF) technology, non-invasive macro X-ray fluorescence (MA-XRF) and desorption electrospray ionization mass spectrometry imaging (DESI-MSI) were applied in situ. Seven industrial synthetic dyes, including auramine O, malachite green, and eosin Y with corresponding by-products, as well as chromium-based pigments considered as dark draft line, were confirmed. By X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS), and micro Fourier transform infrared spectroscopy (micro FTIR, other results showed chalk soil and talc for the outermost coating. According to the synthetic time of industrial dyes and degradation degree of paper, there were at least four occurrences and their specific time periods were speculated.

Limemud resources in the Western Indian offshore: An alternative to high grade limestone and some viable proposals

Several studies have been carried out by various authors on limemud that occurs in the western Indian offshore which is compositionally CaCO3, amorphous, homogeneous, creamy white, soft and non sticky sediments mainly consisting of ooids. The chief mineral constituent of limemud is aragonite. The age, occurrence, formation and estimation of limemud resource are compiled from various published literatures and briefly presented.  Bench scale beneficiation and agglomeration studies for limemud were conducted by Geological Survey of India at the lab of Indian Bureau of Mines and found limemud may be used in steel and filler industries, pharmaceuticals, food, cement etc. The physical and chemical properties of limemud suggest it may be a suitable raw material for the production of stone paper. There are several advantages in manufacturing stone paper in comparison with that of wood pulp paper. A brief comparison between the two compiled from the published literature is presented in the paper. The striking difference is in the consumption of water and emission of CO2e from the production of wood pulp paper and that of stone paper.  A difference of about 1000 kg CO2e emission between the two helps to possess carbon credits. Sustainable mining technology and transportation of limemud from Gujarat offshore to nearby beach facilities are discussed. The approximate costs for limemud mining and transportation are estimated and compared with that of imported high grade limestone from UAE/Oman and is found to be much cheaper. Advantages of limemud and future propositions are briefly submitted for the consideration of the planners.

Experimental and numerical investigation of wicking and evaporation performance of fibrous materials for evaporative cooling

Fibrous materials, such as cellulose papers, fibres, or textiles, are regarded as potential evaporation materials used in evaporative cooling systems. The fibrous material’s wettability and evaporation characteristic have significant influences on heat and mass transfer performance of evaporative cooling systems. This paper studied the wicking performance of selected fibrous materials including cellulose/PET fibre, Coolmax fabric and wood pulp paper by numerical modelling and dedicated experiment based on transient weight and optical measurements. The effect of evaporation on the performance of wicking rise were analysed in depth using the obtained experimental data. The measured data show good agreements with the predicted results, within ± 6.67%, 7.47% and 3.78% errors for the three types of materials, respectively. The microstructure parameters that control water diffusion performance of porous materials, i.e., permeability to effective pore radius ratio, were found to be highest for cellulose/PET fibre followed by Coolmax. Additionally, the study compared water evaporation rate of the selected materials by a few validated preliminary tests operating under various ambient air velocities and surface temperatures. Coolmax and cellulose/PET fibres were found to have similar higher evaporation rate than wood pulp paper. This paper presented numerical and experimental approaches for accurately characterising and differentiating wicking and evaporation performance of fibrous materials which would contribute to optimise evaporation materials for evaporative cooling systems.

Core-shell ammonium polyphosphate@nanoscopic aluminum hydroxide microcapsules: Preparation, characterization, and its flame retardancy performance on wood pulp paper

In the present paper, an environmental fire retardant with core-shell structure ammonium polyphosphate (APP) @ Aluminum hydroxide (ATH) (microencapsulated APP with nanoscale ATH via coprecipitation) was obtained and employed to flame-retard wood pulp paper (WPP). The factors that influence the synthesis of the microcapsule were discussed, and the products with the average diameter of less than 100 nm of the ATH particles formed on APP was obtained at a mutual compound of Al2(SO4)3•18H2O and Al(NO3)3•9H2O with Al molar ratio of 1:9. The optimum reaction conditions including APP kind and amount were studied and 15%APPII@nano-ATH exhibited optimized surface morphology, evenly dispersed state, enhanced water resistance and strong interaction with vapor water. Fundamentally, it imparted WPP excellent flame resistance: for 15 mm * 150 mm WPP, the smoldering rate value of WPP was 100.08 s/150 mm at 1 mg additive amount of the flame retardant, indicating an improvement of 17.7% compared to 85.04 s/150 mm of pure paper; the limiting oxygen index (LOI) of WPP increased from 19.0 to 27.6% at a relatively low 15%APPII@ATH addition of 6 mg. This high-efficient flame retardant performance could be explained by the direct contact and sufficient interaction between APP and ATH which gives full play to their synergy and accelerated the formation of cross-linked P-O-C/Al-O-Al/Al-O-C/Al-O-P/P-O-P structures, leading to a strong and compact char layer with a result of dramatic reduction in heat release rate and smoke production. The specific decomposition and interaction mechanism was conducted associated with the analysis results of thermogravimetric analysis (TGA) and pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) etc.

In‐situ synthesis and adhesion method to prepare phosphorous–nitrogen compounds flame‐retardant wood pulp paper with high efficiency and durability

SummaryIn the present work, flame‐retardant wood pulp paper (WPP) with high water resistance was fabricated through in‐situ synthesis and adhesion of flame retardant on the lignocellulose fibers. Through a simple solution spraying method, melamine (Me) and polyphosphoric acid solution were adequately permeated into interior lignocellulose fibers of WPP in turn and then reacted to produce water‐insoluble phosphorous–nitrogen melamine polyphosphate (MPP). The finally sprayed melamine formaldehyde prepolymer played the roles of flame‐retardant coating, adhesive agent, and water‐proofing layer, thus bonding MPP particles to the lignocellulose fibers firmly. This low‐cost and efficient treatment endowed WPP with excellent flame retardance and satisfactory durability. It showed that the modified WPP had a high limiting oxygen index value of 37.3%, and achieved B‐0 rating in vertical burning test, as well as greatly lowered the peak heat release rate and the total heat release. The flame‐retardant mechanisms of the modified WPP were analyzed and discussed. Moreover, the flame retardance kept well after 72 hours of water resistance test, showing good combination between the flame‐retardant particles and the lignocellulose fibers.

Comparison of Trimethylsilyl Cellulose-Stabilized Carbonate and Hydroxide Nanoparticles for Deacidification and Strengthening of Cellulose-Based Cultural Heritage.

Herein, colloidal dispersions of alkaline nanoparticles (NPs: CaCO3 and Mg(OH)2) are stabilized by trimethylsilyl cellulose (TMSC) in hexamethyldisiloxane and employed to treat historical wood pulp paper by an effortless dip-coating technique. Both alkaline NPs exhibit high stability and no size and shape changes upon stabilization with the polymer, as shown by UV–vis spectroscopy and transmission electron microscopy. The long-term effect of NP/TMSC coatings is investigated in detail using accelerated aging. The results from the pH-test and back-titration of coated papers show a complete acid neutralization (pH ∼ 7.4) and introduction of adequate alkaline reserve even after prolonged accelerated aging. Scanning electron microscopy–energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and infrared and water contact angle measurements showed the introduction of a thin and smooth hydrophobic NP/TMSC coating on the paper fibers. Acid-catalyzed desilylation of TMSC was observed by declining C-Si infrared absorbance peaks upon aging. The CaCO3 coatings are superior to Mg(OH)2 with respect to a reduced yellowing and lower cellulose degradation upon aging as shown by colorimetric measurements and degree of polymerization analysis. The tensile strength and folding endurance of coated and aged papers are improved to 200–300 and 50–70% as illustrated by tensile strength and double folding endurance measurements.

Measurement of Adhesion of In Situ Electrospun Nanofibers on Different Substrates by a Direct Pulling Method

In some cases, we hope to remove the electrospun nanofibrous mesh from the collector easily. But in some cases such as wound dressing, we observe that the in situ electrospun nanofibers can stick to the collector (e.g., skin). Therefore, the adhesion between the in situ electrospun web and the substrate becomes important in the performance and practical application of the electrospun material. In this paper, we reported a direct pulling method to measure the adhesion and understand the adhesion mechanism. In this method, we used gravity to pull the fiber directly from the substrate and then measured the gravity to calculate the adhesion. This new test method is more convenient and practical than the previously reported methods. In addition, the adhesion of the in situ electrospun web on different substrates (e.g., aluminium foil, wood pulp paper, and silicon paper) was also studied by this method. The adhesion was influenced by spinning voltage, electrical conductivity, and surface roughness of the substrates.

Urethane Modified Hydrophobic Compact Wood Pulp Paper for Oil Spill Cleanup: A Preliminary Study

Oil spills and oil/water wastewater are among the great concerns regarding oil pollution. Existing technologies face many limitations and in some cases are responsible for causing secondary pollution, therefore there is as seek for environmental friendly solutions. Biomass, from which celluloses are highlighted, are being employed for oil/water separation or oil absorbents membranes. Usually, these membranes are obtained by freeze drying of CNF (cellulose nano- fibrils) suspensions followed by chemical modification for hydrophobization, which involves expensive process as chemical vapor deposition and expensive reactants as sylanes, turning these processes hardly scalable. Here, we produced a natural porous structure paper from eucalyptus pulp fibers modified by a dipping and heating process in a blocked diisocyanate solution. After the surface treatment, contact angle with water reached 144° and water absorption reduced seven times, keeping the good oil absorbance. The chemical modification process is simple to be performed and use a very low quantity of reactant estimated to be less than 0.1 wt% based on cellulose. The good mechanical properties of the material allows its use in non usual conditions which can be of great importance depending on the environmental conditions.

Preserve Your Books through the Smell.

The identification of paper composition, pH, early signs of paper degradation, and emitting volatile organic compounds (VOCs) are mandatory for effective preventive conservation of paper/books. Sampling restrictions in the analysis of cultural heritage materials limit the choice of appropriate analytical methods. Solvent-free analytical techniques with nondestructive sampling are needed. Addressing this challenge, an electronic nose based on six-coated piezoelectric quartz crystals was assembled and used to analyze VOCs emitted from books. Careful selection of sensor coatings and cluster analysis allowed us to achieve a clear distinction between cotton/linen rag and wood pulp paper, and among the letter group, the discrimination between papers manufactured from alkaline and acidic stocks. This six-element sensor array was therefore able to replace destructive tests as the ones ordinarily used for paper pH measurements. The same electronic nose was able to separate aged pale-yellow paper, a visible initial sign of paper degradation, from well-preserved still white papers, even when made from the same raw material. One of the used sensors detected furfural, often seen as a marker of cellulose degradation, at lower levels than the detection limit found in the literature with gas chromatography-mass spectrometry, a much more complex bulky and expensive instrument.

Alkali-exchanged Y zeolites as superior deacidifying protective materials for paper relics: Effects of accessibility and strength of basic sites

Abstract Paper is the most important writing carrier and its degradation (acidification, aging, and ink removal) is a major issue in the protection of cultural heritage. In this work, we first propose alkali ion-exchanged Y zeolites (Ae-Y) as superior deacidification agents for paper. Their features such as the high surface area, adjustable alkali ion content, strength, good structural stability, and safety/non-toxicity or biocompatibility are very promising for preserving paper-based materials, as demonstrated by aging experiments carried out on both historical wood-pulp paper and modern hand-made bamboo paper samples. Through H2O-mediated dispersion of Ae-Y in target paper samples, the pH of the paper can be modified to a neutral or weakly basic state, and can be maintained for a long time even under harsh accelerated aging conditions. Meanwhile, the Ae-Y coating hardly alters the chromatic aberration and water wettability of papers. This new deacidifying agent does not trigger color changes in alkali-sensitive pigments (i.e., does not cause fading or blanching of pigments). Moreover, a systematic evaluation of the structure-performance relationship indicates the important roles of adequate accessible basic sites and controllable and mild basicity of Ae-Y in the long-term deacidification, anti-aging, and anti-fading effects exerted on paper relics. These findings not only shed light on the design of protective materials for paper-based cultural relics but also expand our knowledge on the deacidification and protection mechanisms of zeolites.

The influence of selected efficient compounds of essential oils for paper protection

Abstract The most common negative influences on lignocellulosic materials from biological point of view include invading of microorganisms, which have in humid environments of porous materials favourable conditions for growth and reproduction. The aim of this study was to assess the influence of selected compounds present in essential oils- EOs (linalyl acetate-LA and citral-C) and the accelerated ageing process on the chemical (cellulose degree of polymerization, content of saccharides), mechanical (tensile index) and physical (fibres length distribution) properties of papers. LA and C were evaluated as the compounds with the highest antimicrobial activity and therefore, they were applied into the paper mass in form of their vapours. Paper samples were prepared from five types of material. Chemical changes were evaluated by wet chemical methods, size exclusion chromatography and high performance liquid chromatography, mechanical property according to ISO 1924-2 standard and morphological properties of fibres by using Fiber Tester equipment. In the view of followed properties, the protecting impact of these EOs efficient compounds has a greater importance in their application before the ageing process itself, especially at wood pulp papers and papers produced from sulphate deciduous pulp. The contents of both holocellulose and a cellulose degree of polymerization were significantly correlated with the tensile index of the paper.

Strengthening of paper by treatment with a suspension of alkaline nanoparticles stabilized by trimethylsilyl cellulose

Control over the mechanical properties of cellulose-based artifacts (e.g. paper) is highly important in cultural heritage science. Especially, a non-aqueous method that does not cause swelling but can be applied to either single paper sheets or bound cellulose items (e.g., books) without any preselection is currently needed. Herein, we present a new multilayer deposition method that can simultaneously deposit alkaline reserve and improve the mechanical properties of historic wood pulp (HWP) paper, which often suffers from high fragility and brittleness. Alkaline nanoparticles (magnesium hydroxide Mg(OH)2NPs) stabilized by hydrophobic cellulose derivative i.e., trimethylsilyl cellulose (TMSC) in hexamethyldisiloxane (HMDSO) are prepared and deposited in the form of multiple layers on HWP paper by a technically effortless dip coating procedure. An enhanced and irreversible deposition of Mg(OH)2 NPs–TMSC and an alkaline reserve (AR) up to 4% (139 meq[OH−]/100g) are achieved as revealed by infrared spectroscopy and back-titration measurement. The tensile strength of uncoated HWP paper (1.6 MPa) is increased to 5.5 MPa after coating with Mg(OH)2NPs/TMSC (before aging) and then to ca 9 MP (after accelerated aging). In the latter case, the TMSC is transformed to cellulose by cleaving of O–Si bonds. The surfaces are evenly covered with thin and transparent coatings of hydrophobized nanoparticles as demonstrated by electron scanning microscopy and contact angle measurements.

Effective use of biomass ash as an ultra-high humidity sensor

The paper reports a facile, green, cost-effective, and sustainable track to fabricate humidity sensors with superior performance. This frugal way make use of biomass ashes, left by combustion and annealing of natural wood pulp paper, that can emerge as an alternative source of sensing materials. In comparison to other humidity sensors, the optimized humidity sensor based on annealed tissue ash exhibited ultra-high sensitivity of six orders of magnitude (∼106), excellent selectivity (against H2, CO, CH4) and good stability (1–8 weeks) in the range of 15–90% RH at room temperature. Further characterization was carried out to elucidate the sensing mechanism, which includes chemical composition, functional group, crystal structure, surface morphology and elemental composition of the ashes by XRF, FT-IR, XRD, SEM and EDS analysis, respectively. The proposed strategy and fabricated sensors also enable the real-time humidity monitoring in human breath, which demonstrates the feasibility of its practical application ability as a flexible and wearable humidity sensor.

Energy and carbon coupled water footprint analysis for Kraft wood pulp paper production

Although paper production demonstrates high energy and water sensitivity in their life cycles, only a few systematic analyses have focused on these issues. Therefore, an energy and carbon coupled water footprint analysis of five types of Kraft wood pulp-based paper (i.e., specialty-, art-, household-, light coated-, and tissue paper) is conducted in this study to help improve the environmental performance of the paper industry. All investigations are conducted with an impact-oriented approach based on ISO standards. Results show that elemental-chlorine-free bleaching is more environmentally friendly than chlorination-alkaline extraction-hypochlorite bleaching, specifically for global warming, aquatic eutrophication, and human health (i.e., carcinogens and non-carcinogens). Gray water footprint along whole life cycles of each product is approximately twice of blue water footprint. Direct processes contribute approximately 50% to water scarcity, while their impact on aquatic eutrophication ranges from 0.002% to 50.72%. For other midpoints, indirect processes dominate the influences. Meanwhile, COD, BOD5, CO2, TP, Cr (Ⅵ), Ti, Hg, and As are key contributors. Finally, reusing sludge by direct burning in the recovery furnace, reclaiming organic compounds in black liquor before alkali recycling, and integrating black liquor gasification technology are expected to provide substantial environmental benefits. Amelioration of wastewater treatment, optimization of the national energy structure, and improvement of the efficiency of chemicals and freshwater are recommended.