Starch is one of the most common biodegradable polymers found in nature, and it is widely utilized in the food and beverage, bioplastic industry, paper industry, textile, and biofuel industries. Starch has received significant attention due to its environmental benignity, easy fabrication, relative abundance, non-toxicity, and biodegradability. However, native starch cannot be directly used due to its poor thermo-mechanical properties and higher water absorptivity. Therefore, native starch needs to be modified before its use. Major starch modification techniques include genetic, enzymatic, physical, and chemical. Among those, chemical modification techniques are widely employed in industries. This review presents comprehensive coverage of chemical starch modification techniques and genetic, enzymatic, and physical methods developed over the past few years. In addition, the current applications of chemically modified starch in the fields of packaging, adhesives, pharmaceuticals, agriculture, superabsorbent and wastewater treatment have also been discussed.

Purpose Even though Sri Lanka has established Early Warning (EW) mechanisms and Evacuation Procedures (EP) for the communities affected by the coastal disasters, there are several gaps, which hinder effective mechanisms in operation of disaster management practices. These gaps affect both the vulnerable communities and relevant authorities involved in the Disaster Management sector. This paper aims to identify and evaluate those gaps while providing adequate solutions. Design/methodology/approach For that, questionnaire surveys were carried out with a sample size of 217 via an online survey (117) among the urban level and interviews and telephone interviews (100) with the village level coastal communities. Data analysis was carried out using statistical analysis of questionnaire surveys and grounded theory was used for in-depth qualitative study. Findings Primary and secondary data obtained from the surveys were categorized under five themes, namely, response to early warning systems, evacuation routes, shelters, drills and training, effect of having a family vehicle, relatives and domestic animals, evacuation of people with special needs and cooperation with local government units. This paper analyses these themes in detail. Originality/value While critically evaluating the gaps in existing early warning mechanisms and evacuation procedures, this paper identifies correlations between some of the gaps and recommendations as well. Input from the international academics were also obtained at different forums and have strengthen the findings to overcome the barriers, which hinder successful mechanisms.

In this study, two types of modified cassava starch samples (MCS and MWS) prepared from commercially available native cassava starch (NCS) and native cassava starch extracted using the wet method (NWS) were investigated for the removal of Pb(II) ions from aqueous solutions. MCS and MWS samples were synthesized under acidic conditions using Pluronic 123 as the structure-directing agent and tetraethylorthosilicate (TEOS) as the chemical modifying agent. Modified starch samples were characterized using Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), X-ray Diffraction (XRD), and a nitrogen (N2) gas adsorption–desorption analyser. MCS and MWS showed enhanced thermal stabilities upon acid hydrolysis and chemical modification. The effects of contact time and initial Pb(II) concentration were studied through batch adsorption experiments. Adsorption kinetics followed the pseudo-second-order kinetic model. The equilibrium adsorption data were analysed and compared by the Langmuir and Freundlich adsorption models. The coefficient correlation (R2) was employed as a measure of the fit. The Langmuir model fitted well with equilibrium adsorption data, giving a maximum Pb(II) adsorption capacity of 370.37 and 294.12 mg/g for MWS and MCS, respectively. Modified samples exhibited a higher desorption efficiency of over 97%. This study demonstrated that modified starch could be utilized for Pb(II) removal from industrial wastewater.

No abstract

No abstract