Strength and compressibility behaviors of expansive soil treated with coffee husk ash

Various factors can affect the durability of roads, such as the strength of sub-grade, the quality of the subbase and base course, the environments and properties of the soil used. Particularly, roads built on expansive soil are susceptible to early damage due to the swelling and shrinkage characteristics of this kind of soil under changing moisture conditions. The most common technique used to improve the properties of problematic soil is stabilization with additives. Using waste materials to improve the properties of expansive soil is a recent trend in soil stabilization. This study deals with the treatment of expansive soil with coffee husk ash(CHA). Coffee husk is a by-product of coffee production, and CHA is the resulting ash after burning it. In this study, the bearing capacity and compressibility characteristics of expansive soil(specifically black cotton(BC) soil) stabilized with varying percentages of CHA(5%, 10%,15%, and 20%) are investigated. Then, scanning electron microscopy(SEM) and energy dispersive X-ray(EDX) were used to analyze the influence of CHA on surface morphology and chemical composition of the studied soil. The results showed that the soil treated with CHA is generally improved in terms of strength.Addition of 20% CHA increases the bearing capacity of the soil by three-fold. In addition, the morphological studies of the soil samples treated with 10% and 15% CHA indicated the formation of hydrated particles and cementitious compounds as a result of the reaction between the soil and CHA. This indicates the potential usage of CHA as a stabilization agent and subsequently, it can address the disposal and environmental concerns related to coffee husk.

Reinforcement of Thermoplastic Starch Films with Cellulose Fibres Obtained from Rice and Coffee Husks

Cellulosic fibres from coffee(CF)and rice(RF)husks have been obtained applying chemical treatments and characterized as to their microstructure and thermal behaviour.These materials have been incorporated into glycerol plasticised thermoplastic starch(TPS)films obtained by melt blending and compression moulding at 1 wt%,5 wt%and 10 wt%.Microstructure,thermal behaviour and optical,tensile and barrier properties of the composites were analysed.Both kinds of micro-fibres improve the film stiffness while reduced the film stretchability.However,CF better maintained the film ductility at 1 and 5 wt%.A network of fine oriented fibres was observed on the surface of the films,while internal fibres exhibited a good adherence to the polymer network.The water vapour permeability of TPS films was not reduced in composites,although oxygen permeability was lowered by about 17%.Film transparency decreased by fibre addition in the UVVIS range.Thermal stability of composites was slightly higher than net TPS films.

Paracetamol Sensitive Cellulose-Based Electrochemical Sensors

Electrochemical determination of paracetamol(PCT)was successfully performed using carbon paste electrodes(CPEs)modified with treated coffee husks(CHt)or cellulose powder(Ce).Scanning electron microscopy was used to characterize unmodified or modified CPEs prior to their use.The electrochemical oxidation of PCT was investigated using square wave voltammetry(SWV)and cyclic voltammetry(CV).The oxidation current density of PCT was two-fold higher with the CPE-CHt sensor and 30%higher with CPE-Ce in comparison with the unmodified CPE,and this correlated with the higher hydrophilicity of the modified electrodes.Using SWV for the electrochemical analysis of PCT,carbon paste electrode modified with raw coffee husks(CPE-CHr)showed the presence of impurities at+0.27 V/SCE,showing the interest in using pure cellulose for the present analytical application.Furthermore,CPE-Ce presented a higher real area compared to CPE-CHr,which explains the increase in the limit of saturation from 400 mg/L to 950 mg/L.The better saturation limit exhibited by CPE-Ce justifies its choice for electroanalysis of PCT in commercialized tablets.The proposed method was successfully applied in the determination of PCT in commercialized tablets(DolipraneR 500)with a recovery rate close to 100%,and no interference with the excipients contained in the tablets analyzed was observed.This novel sensor opens the way for sustainable development of electroanalytical control of drugs sold individually in developing countries.

Recovery of Biomass Incinerated as Struvite-K Precipitates Followed Aluminium Removal

Phosphorus (P) and potassium (K) are non-renewable materials and widely in many industries such as agricultural sectors. On the other hand, the demand of P and K as fertilizers increases which following global population. The nutrient source of P and K which get from biomass waste i.e. incinerated of activated sludge and coffee husk biochar, respectively. The present study was conducted recovery of P and K as struvite-K (KMgPO4·6H2O) precipitates. The results showed that aluminium was released simultaneously with P from incinerated activated sludge with precipitate of Al:P of 1:1, K:P of 0.5, and Mg:P of 3. However, aluminium was inhibited to form struvite-K. Then, we examined cation removal especially for removed Al by dissolved 0.5 M HNO3 and the solution was mixed with KH2PO4 and MgCl2·6H2O as source of K and Mg, respectively. The results showed aluminium (Al) was removed with precipitate K:P of 0.5, and Mg:P of 0.8. This study was confirmed that recovery of biomass incinerated was successful as struvite-K and can be used as fertilizers.

Study of Potassium Recovery from Biomass Ash Using Tartaric Acid and Syngenite Method

Biomass has the potential and benefits of being an alternative energy source to replace fossil fuels that exist today in Indonesia and other tropical countries. In addition, biomass has an abundant stock or supply. By assessing the feasibility of recovering potassium, it is hoped that more potassium resources and in future Indonesia will be dependent on imported fertilizers and increase the agricultural industry, which is the aims of this study. The best extraction result is using CH3COOH. Treatment of 1:10 solid-liquid ratio with the help of 1 mol/l CH3COOH was chosen as the best treatment because it is more economically efficient. Recovery of K with the help of tartaric acid and acetic acid resulted in a K recovery efficiency of around 94%. The optimal condition for the syngenite method is the addition of a magnesium dose of 5 mmol/l and at pH 11, the Ca: K ratio is 1:2.1 with 42% K. This can be a suggestion which method is more effective and efficient in recovery K.

Short-term application of biochar increases the amount of fertilizer required to obtain potential yield and reduces marginal agronomic efficiency in high phosphorus-fixing soils

There is little understanding as to whether the addition of biochar requires less fertilizer to obtain the potential yield.Furthermore,the additional yield ascribed to the non-nutrient effects of biochar is ambiguously quantified.Therefore,this study is aimed to elucidate the influence of biochar application rate and production temperature on(i)marginal agronomic efficiency(AELN),(ii)potential yield(Yopt),(iii)the amount of mineral fertilizer required to obtain the potential yield(Fopt);and(iv)nutrient use efficiency.AELN,Yopt and Fopt were calculated after fitting the yield response at different levels of mineral fertilizer with a second-degree polynomial.Application of biochar reduced marginal agronomic efficiency,implying that the plant utilized the applied nutrient more efficiently without biochar at a low dose of mineral fertilizer.Biochar increased potential yield but required more mineral fertilizer to obtain the optimum yield.The non-nutrient associated effect of biochar reached to 39% and is mainly attributed to its liming effect.The effect of biochar on AELN,Yopt,Fopt,fertilizer use efficiency and soil pH were more pronounced at the higher application rate.Addition of biochar,however,increased soil Mehlich-P and carbon content,irrespective of production temperature and application rate.This study demonstrated that the short-term effect of biochar application on fertilizer utilization should be examined with caution in low-input cropping systems because the biochar effects were dependent on fertilizer level,biochar application rate,production temperature and their interactions.Further manipulative experiments are recommended to identify the mechanisms that explain the non-nutrient effect of biochar on yield.