Air pollution constitutes the greatest environmental threat to human health in the European Union. In Poland, the emission of particulate matter and harmful gases originating from local coal based boiler plants and the combustion of fuels in residential heating appliances is a considerable source of air pollution. The combustion of fuel in home furnaces is inefficient due to the use of cheap fuels of low heating parameters and the frequent addition of waste. For the purpose of the research, deciduous tree wood pellets were selected as the basic fuel with the admixture of plastic waste, rubber, waste paper, wood residues, diapers, textile waste, multi-material packaging, construction waste, biomass and alternative fuel (RDF). Examining ash samples to confirm the practices of combusting or co-combusting waste materials in heating appliances is considered to be one of the most reliable detection methods; however, the results of direct research require further data processing. The application of hierarchical clustering analysis to the obtained results arranged into a matrix enabled in a simple way to demonstrate the similarities between the examined samples of fuel and the samples of fuel mixed with waste materials in the parameters space as well as to analyze the similarities among the measured parameters (the content of particular elements in ash) in the space of the examined samples. The application of chemometric methods for the purpose of identifying the combusted fuels, and, in particular the co-combusted waste complements the currently used monitoring tools which control the use of low quality fuels or the combustion of waste of different origin.

Demand for particleboards keeps increasing and as such more trees are fell for its production, engendering deforestation. For the purpose of reducing falling of trees, this study, focused on recycling of waste paper in the development of paperboard as alternative to particleboards used for furniture and interior household applications. Kenaf fiber (KF) was blended at varying proportions of 0, 1, 2, 3, 4, and 5 wt.% with 20 wt.% constant cement and 20 wt.% constant coconut shell powder while the remaining was paper pulp. Board specimen developed were cured for 14, 28, and 90 days and mechanical properties were examined. Results obtained showed that fiber dosage improved bond strength and screw holding strengths as compared with the control mix. Similarly, modulus of rupture was enhanced with KF loading as compared with control mix while 1 to 3 wt.% KF spawned enhancement of modulus of elasticity. However, 4 and 5 wt.% KF led to a reduction in the modulus. Infusion of the fiber enhanced tensile strength from 1 to 3 wt.% content. 14-day and 28-day curing periods were observed to improve properties while the 90-day curing period is detrimental to all properties. Optimization via signal-to-noise ratio revealed an optimum mix of 2 wt.% obtained for fiber and an optimum curing duration of 28 days.

The main objective of the present study was to determine the optimum C/N ratio for converting waste paper and chicken manure to nutrient-rich manure with minimum toxicity. Six treatments of C/N ratio 20, 30, 40, 50, 60, and 70 (T1, T2, T3, T4, T5, and T6, respectively) achieved by mixing chicken manure with shredded paper were used. The study involved a composting stage for 20 days followed by vermicomposting with Eisenia fetida for 7 weeks. The results revealed that 20 days of composting considerably degraded the organic waste mixtures from all treatments and a further 7 weeks of vermiculture significantly improved the bioconversion and nutrient value of all treatments. The C/N ratio of 40 (T3) resulted in the best quality vermicompost compared to the other treatments. Earthworm biomass was highest at T3 and T4 possibly due to a greater reduction of toxic substances in these waste mixtures. The total N, total P, and total K concentrations increased with time while total carbon, C/N ratio, electrical conductivity (EC), and heavy metal content gradually decreased with time during the vermicomposting process. Scanning electron microscopy (SEM) revealed the intrastructural degradation of the chicken manure and shredded paper matrix which confirmed the extent of biodegradation of treatment mixtures as result of the composting and vermicomposting processes. Phytotoxicity evaluation of final vermicomposts using tomato (Lycopersicon esculentum), radish (Raphanus sativus), carrot (Daucus carota), and onion (Allium cepa) as test crops showed the non-phytotoxicity of the vermicomposts to be in the order T3 > T4 > T2 > T1 > T5 > T6. Generally, the results indicated that the combination of composting and vermicomposting processes is a good strategy for the management of chicken manure/paper waste mixtures and that the ideal C/N ratio of the waste mixture is 40 (T3).

Environmental pollution and the exploitation of fossil-based products are topical issues that should be a matter of concern to the global population. The production of bio-based substances from waste biomass is a way to reduce the consumption of fossil fuels and limit environmental pollution. Enzymatic catalysed saccharification of cellulose is an important step for the bio-conversion of biomass such as waste paper into glucose that could be utilized as a feedstock for the production of value added bioproducts and this process can also be considered as an alternative route of waste management. During this study, fresh cellulase enzyme from Trichoderma viride was incubated separately with seven different waste paper materials during twelve successive incubation periods of 2 h each. The amount of sugar released from each paper material during each incubation period was determined. The highest sugar concentration released from each paper materials was produced during the first incubation period except the filter paper for which the highest amount of sugar was produced during the 9th period of incubation. During these optimum sugar producing incubation periods the highest total sugar concentration was released from brown envelope paper (3.3 mg.mL-1 followed by foolscap paper (3.0 mg.mL-1) and office paper (2.8 mg.mL-1) while the lowest amount of sugar was released from Pick ?n Pay paper (0.6 mg.mL-1). The relative saccharification percentage was also calculated which showed that filter paper produced the highest amounts of sugar followed by newspaper, and foolscap paper with advertising paper from a retailer. Pick ?n Pay offered the highest resistance towards cellulase catalysed bio-conversion into sugar.

In this study, a composite aerogel (WP-MMT) composed of wastepaper (WP) and montmorillonite (MMT) was prepared by ambient pressure drying technology to adsorb Cd²⁺. The study of compression performance indicated that the composite aerogel had ideal mechanical strength when the mass ratio of WP to MMT was 1:1. The specific surface areas of the aerogels modified by hydrogen peroxide (WP-MMT-H₂O₂) and sodium hydroxide (WP-MMT-NaOH) were increased greatly. The sorption isotherms and kinetics of Cd²⁺ sorption on WP-MMT-H₂O₂ and WP-MMT-NaOH were investigated. The Cd²⁺ sorption data could be well described by a simple Langmuir model, and the pseudo-second-order kinetic model best fitted the kinetic data. The maximum sorption capacity obtained from the Langmuir model was 232.50 mg/g for WP-MMT-NaOH. The adsorption mechanism of WP-MMT was chemical adsorption of a single-molecule layer. In general, it was proved that the composite aerogel with high adsorption capacity of Cd²⁺ could be synthesized from modified WP and MMT by ambient pressure drying. The composite aerogel fabricated by wastepaper and montmorillonite showed bright application prospect in the aqueous heavy metal pollution control.

When old corrugated cardboard (OCC) is returned to the paper mill for repulping and reuse, the starch, which is added to the paper surface as a reinforcement agent, is dissolved into the pulping wastewater. Most of the OCC pulping wastewater is recycled to save precious water resources; however, during the water recycling process, the accumulation of dissolved starch stimulates microbial reproduction, which causes poor water quality and putrid odor. This problem seriously affects the stability of the papermaking process and product quality. In this study, phosphomolybdic acid (H₃PMo₁₂O₄₀, abbreviated as PMo₁₂) was utilized to catalyze the waste starch present in papermaking wastewater to monosaccharides, realizing the resource utilization of waste starch. The results showed that the optimized yield of total reducing sugar (78.68 wt%) and glycolic acid (12.83 wt%) was achieved at 145 °C with 30 wt% PMo₁₂ at pH 2, which is equivalent to 91.51 wt% starch recovered from wastewater for resource utilization. In addition, the regeneration of the reduced PMo₁₂ was realized by applying a potential of 1 V for 2 h. Overall, this study has theoretical significance and potential application value for resource utilization of waste starch in OCC pulping process and cleaner management of OCC waste paper.

The quest for cost-effective and thermal efficient structural materials onto beating the high cost of construction is gaining more attention among researchers. This study focused on the blending of cement and sand with waste paper pulp into cost-effective structural materials. The composites were prepared in four mix groups with each containing a fixed amount of sand at 5, 10, 15, and 20 wt.% (by weight of pulp). Cement was varied at 10, 20, 30, and 40 wt.% in each group, and curing was done for 28 days. Properties evaluated are compressive, bending, and splitting strengths. It was observed that increasing cement and sand contents enhanced strengths; howbeit, the blend of 30 wt.% cement/15 wt.% sand resulted in a reduction in bending strength even as 30 wt.% cement/20 wt.% sand engendered a decrease in bending and splitting strength. The microstructural features showed that inherent fibers of the pulp were well bonded with hydration products and sand content yielding good performance in the composites. The optimization procedure carried out depicted a combination of 35.27% cement and 20% sand as the optimum composition. Experimental outcomes were modelled for the purpose of prediction of responses. The models were confirmed statistically fit showing how varying cement content affected strength responses at fixed sand proportion. ANOVA affirmed the significant contribution of cement and sand on the strength responses. Compliance reliability was observed to be dependent on the interactive pattern between cement and sand. Going by the standard prescription for the strength properties, cement and sand content of 35.27 and sand 20 wt.% satisfied all strength requirements for low-cost construction having a compliance reliability of 1.31.

The potential of alkaline cellulo-xylanolytic enzymes from non-pathogenic Bacillus subtilis strain was tested for deinking of photocopier waste paper. Cellulase and xylanase play a crucial role in deinking of different types of waste paper. Partial purification of cellulo-xylanolytic enzymes was carried out using ultrafiltration followed by ammonium sulfate precipitation. The ultrafiltered enzyme was used for deinking the photocopier waste paper along with chemical deinking. An enzyme dose of 0.6 IU/g and reaction time of 60 min for ultrafiltered cellulo-xylanolytic enzyme significantly increased deinking efficiency, tear index (9.52%) and folding endurance (5±2%) as compared to chemical deinking. There was improvement in strength properties such as tear index and double-fold along with freeness of pulp (18%). There was slight decrease in tensile index (0.6%) and burst index (16%) while ISO brightness remained unaffected. Enzymatic deinking (74.3%) by ultrafiltered cellulo-xylanolytic from Bacillus subtilis was found significant over conventional chemical deinking.

The efficiency of xylano-pectinolytic enzymes, co-produced by a single microbial strain Bacillus pumilus, was analysed for the recycling of mixed office waste paper through deinking and compared with the alkaline chemical deinking method. Enzymes showed maximum deinking at pH 8.5, pulp consistency of 10%, xylanase-pectinase dose of 12 and 4 IU per gram pulp, respectively, after 120 min of deinking period, and temperature at 50 °C. A chemi-enzymatic approach was employed with xylano-pectinolytic enzymes and various concentrations of deinking chemicals, which showed that enzyme-treated mixed office waste pulp requires only 40% chemicals for deinking, in order to get the almost same level of various handsheets properties, as obtained by the chemical method with 100% chemicals. Similarly, the effluent load of BOD and COD contents was also decreased by 17.90 and 19.75%. This combinational approach of deinking significantly improved the various properties of the handsheets and resulted in gain of 7.5, 9.38, 6.33 and 11.65% in tear factor, burst factor, breaking length and viscosity of the handsheets, while the effective residual ink concentration analysis of deinked handsheets of mixed office waste paper showed deinking efficiency of 22.45%, which revealed the removal of ink particles during enzymatic deinking steps.

A potential new way of producing coal fly ash-based granular synthetic aggregates (CSA) using waste coal fly ash (CFA), paper waste, lime, and gypsum and their utilization as a soil ameliorant to improve crop production in low productive acidic red soil in Okinawa, Japan were studied. The red soil was amended with CSA at three different mixing ratios (i.e., CSA/soil—1:1, 1:5, and 1:10) for the cultivation of Brassica rapa var. Pervidis commonly known as Komatsuna, and the physico-chemical parameters of CSA-soil mixtures and plant growth were analyzed. Incorporation of CSA to the red soil improved the physical and chemical properties of the soil such as water holding capacity, hydraulic conductivity, bulk density, pH, exchangeable cation concentration, cation exchange capacity, particle size distribution, soil pH, electrical conductivity, and carbon content. CSA amendment at ratios of 1:1, 1:5, and 1:10 decreased bulk density by 29.39%, 14.28% and 11.11%, respectively, compared to the original red soil. The acidic pH of the red soil (5.12) was increased to 7.13 and 6.37 by CSA/soil ratios of 1:5 and 1:10, respectively. CSA amendment in soil at 1:5 ratio increased water holding capacity, saturated hydraulic conductivity, electrical conductivity, cation exchange capacity, carbon, potassium (K), magnesium (Mg), and calcium (Ca) content by 0.06 kg kg⁻¹, ten times, 15.95 mS m⁻¹, 1.76 cmolc kg⁻¹, 6.07 g kg⁻¹, 0.42 g kg⁻¹, 0.24 g kg⁻¹, and 3.38 g kg⁻¹, respectively, in comparison to the original red soil. Heavy metal contents of the CSA-soil mixtures were below the maximum pollutant concentrations suggested by the US Environmental Protection Agency. Moreover, Na, K, Mg, Ca, copper (Cu), and zinc (Zn) contents in the CSA-soil mixtures increased in comparison with the original red soil. CSA amendment in soil at the ratio of 1:5 and 1:10 resulted in an increase in plant height and plant fresh weight by three and 12 times, respectively, and there was increase in N, K, Mg, Ca, Cu, and Zn contents of the shoots. The results suggest that utilization of eccentric CSA as soil amendment agent can be regarded as an effective waste management practice.