Avanços na reciclagem e gestão de resíduos

Heavy Metal recovery is one of the serious problem in this world. Many Industries were discharged their effluent into the water bodies (lakes, rivers etc.,) without any prior treatment. Tanneries are the type of industry which delivers the effluent with high concentration of Hexavalent Chromium (Cr6+). It should directly affects the lungs and causes the cancer. The present study has reviewed the removal of Hexavalent Chromium (Cr6+) from various natural adsorbents

Food waste is a problem in developing countries which Malaysia is not exempted, it leads to loss of potential valuable food sources that can be recycled in other forms of energy, waste resources and generated emissions from the food supply chain and challenges associated with disposing organic waste to landfill. This study focused on examining food wastage profile at the household consumer stage in Malaysia. Data collected through questionnaires was given to 311 respondents at Serdang and Cheras area in Malaysia based their leftover food generation and food purchase. Independent sample t test suggest there is no significant difference in the response to not always having leftover food with Serdang (M=3.12, SD=1.19) and Cheras with a sample size of 157 (M=3.04, SD=1.31), t (309)=0.598, p=0.55 (two tailed). The magnitude of the difference in the means (mean difference=0.85, 95% confidence interval; -0.19 to 0.37 which was very small. there was a significant difference in the score for waste generated in ringgit between Serdang and Cheras Kuala lumpur (Serdang Mean=7.85, SD=3.09) and (cheras Mean=12.12, SD=5.09); t (257.98)=-4.77 with a mean difference of -2.27, 95% confidence interval of -3.208 to -1.333 which is very large. Wastage of food in Cheras area is more than in Serdang Correlation revealed that income, race, food purchase and type or number of house occupant had a positive correlation with the total amount of food waste. Curtailing food waste would increase sustainability and human health in Malaysia thus reducing the stress placed on municipal solid waste management.

Large amounts of bones and trimmings are generated as a by-product of the poultry industry in mechanical deboning of chicken. These by-products are potential sources of valuable components such as proteins and nutrients. Enzymatic hydrolysis of animal by-products can be used to separate lipids and produce protein lipid hydrolyzates resulting in the formation of insoluble sediment rich in phosphorus and nitrogen. In this study, the sediment from the enzymatic hydrolysis of mechanically deboned chicken is hydrothermally treated to evaluate the possibility for nutrient recycling. Hydrothermal processing was performed at elevated temperature of 150°C and 220°C using water as the reaction medium with varying pH and time. The elemental composition of the liquid and solid fractions was measured after the treatments. With higher pH, the majority of phosphorus was distributed to the solid fraction while with pH 1 the majority of phosphorus was found in the liquid fraction. Nitrogen was concentrated in the liquid fraction in all processing conditions. The major part of the carbon was distributed to the liquid fraction.

Agricultural farm-wastes produced after harvest of every crop are of great concern because of the problems of environmental pollution, rural sanitation, recycling and utilization. We have standardized a process of bioconversion of agricultural farm wastes at the farmer's own fields into biocompost for field application and further value-addition of bio-compost thus produced with the help of microbes of defined functional traits like biocontrol agents, plant growth promoters, phosphate solubilizers and nutrient mobilizers. After standardization of the whole process, the same was demonstrated to 456 farmers in different villages of Eastern Uttar Pradesh, India. Various farmer groups have adopted the process of bioconversion to produce biocompost and value-added bio-farm-inputs and commercialized the products for gaining economic livelihood.

Nanotechnologies are in the process of increasing their development in research and in industries. Thus, there is also an increase in the production of waste in nanoscale. There is an alert point: as the challenges brought by nanotechnologies are not yet completely known, given the different physicochemical characteristics of the nano scale, the same will happen in the production of nano waste. Can garbage containing nano particles be added to waste with larger particles? What are the risks and how to establish the regulation? The paper intends to show that the documents already produced by the OECD-The Organization for Economic Co-operation and Development (OECD) since the year 2006, in the series of studies entitled "Series on the Safety of Manufactured Nanomaterials", focusing on the safety assessment of nanomaterials, could be an alternative for the lack of regulation. In fact, 80 specific documents have already been published in this regard, and one study, specifically, entitled “Nanomaterials in Waste Streams: Current Knowledge on Risks and Impacts”, handling waste. These documents may serve to develop a non-legislative regulatory framework through Dialogue between the sources of Law, anchored in legal pluralism (Gunther Teubner) in order to organize flexible legal rules, but in conditions of disciplining the safe treatment of nano waste.

Water contamination by substantial metal particles and natural squanders is one of the major environment issues. Dangerous metal particles like Hg, Cr, Cd, As, Pb, Ur, and so forth are superfluous metals and thought to be of extraordinary risk for amphibian life, people, plants and other creature. These dangerous metal particles are specifically surrendered into water by sundry mechanical applications and by other human exercises. Magnetite nanocomposites are very much kenned adsorbents for the reflection of awkwardly substantial metal particles from water. Because of their foremost physiochemical properties, cheap strategy and easy recovery within the sight of outside attractive field make them additionally enrapturing towards water cleaning. This survey fundamentally assesses the potential use of surface built magnetite nano-adsorbents in water sanitization.

This study discussed the Artificial Neural Network (ANN) based classification technique is applied for the prediction of percentage adsorption efficiency for the removal of Co2+ Ion from Aqueous Solutions by Loess Soil Nanoparticles. The effect of operational parameters was performed to investigate the effect of pH, contact time, initial concentration, and temperature on adsorption process are studied to optimize the conditions for maximum removal of Co2+ Ion. The experimental data were studied in terms of kinetic characteristic of adsorption using pseudo-first-order and pseudo-second-order models, and it was found that Co2+ Ion adsorption on both adsorbent fitted well with pseudo-second-order models. The equilibrium experimental data were analyzed using Langmuir and Freundlich isotherm models. The finding indicated that Loess Soil Nanoparticles especially could be used as an appropriate adsorbent to remove potentially harmful metals such as Co2+ Ion from contaminated water.

Water plays a major role in the Algerian Sahara; it is the main cause of sustaining life of all living in an arid environment. Farmers in Beni Abbes exploiting groundwater for irrigation and to supply the urban center of the oasis, now the size of the palm grove of Beni Abbes shrink by over 50%, that is to say from 40 hectares to 20 hectares only, the oasis suffers from several causes of degradation, which are many: the overexploitation of groundwater aquifers by the anarchical use of pumps and boreholes, salinity of water and soil after the lowering of the groundwater level, the narrowness of the land due to inheritance, the negligence of the earth by the youth due to lack of their production efficiency. The fellahs of the oasis used several traditional techniques to bring water from the groundwater aquifers to its land and dwellings, as foggaras, the pendulum wells (shadoof wells), the accumulations basins and open channels (seguias). Our objective of this work is to study the current state of the oasis and the impact of the use of modern irrigation systems on water and soil of the oasis.