Solid waste characterization and recycling potential for a university campus

Integrated waste management systems are one of the greatest challenges for sustainable development. For these systems to be successful, the first step is to carry out waste characterization studies. In this paper are reported the results of a waste characterization study performed in the Campus Mexicali I of the Autonomous University of Baja California (UABC). The aim of this study was to set the basis for implementation of a recovery, reduction and recycling waste management program at the campus. It was found that the campus Mexicali I produces 1ton of solid wastes per day; more than 65% of these wastes are recyclable or potentially recyclable. These results showed that a program for segregation and recycling is feasible on a University Campus. The study also showed that the local market for recyclable waste, under present conditions - number of recycling companies and amounts of recyclables accepted - can absorb all of these wastes. Some alternatives for the potentially recyclables wastes are discussed. Finally some strategies that could be used to reduce waste at the source are discussed as well.     

Characterization of acute toxicity,genotoxicity, and oxidative stress of dimethoate in Rhinella arenarum larvae

Environmental Science and Pollution Research - There is a great concern worldwide about the global decline of amphibians, particularly by agrochemical pollution. The aim of this study was to assess...     

Effects of farmyard manure and chemical fertilizers on the nutritional status of the loquat trees

The nutritional status of the loquat trees was investigated using cattle manure and commercial fertilizers for three years. The farmyard manure increased N, P, K, Mg, Fe and Zn contents of the leaves. No significant difference was found between the fertilizer types for trunk growth. Yield efficiency was nearly doubled by application of farmyard manure. Fertilizers did not affect the weight and shape of the fruits; however, commercial fertilizers led the lower total acidity in fruits. It was concluded that the loquat trees grown in sandy soils could fulfill their principal nutrient requirements for growth and commercial yield with application of farmyard manure.     

Hormetic effect of glyphosate on Urochloa decumbens plants

Abstract

Urochloa decumbens plants may be reached by herbicide drift from applications of glyphosate from neighboring areas or by variations during applications. Considering the different phenological stages and size of plants in these areas, the amount of active ingredient that reaches the plants probably varies. The objective of this study was to evaluate the effects of the application of different doses of glyphosate on U. decumbens plants. Two greenhouse experiments were conducted with two replications at different times. The first experiment evaluated the biological response of U. decumbens plants to glyphosate doses (0, 2.81, 5.63, 11.25, 22.5, 45, 90, 180, 360, 720, and 1,440?g a.e. ha^?1), with six replications. The second experiment evaluated the response of U. decumbens plants to the application of a selected low dose of 11.25?g a.e. ha^?1. Evaluations of injury were performed at 0, 7, 14, and 21?days after application, and dry weight of plants was determined for each evaluation period. U. decumbens plants increased in dry weight when using the glyphosate dose of 11.25?g a.e. ha^?1. However, plants had different responses to the application of this low dose. It can promote both stimulation and inhibition of plant growth.     

Genetic connectivity of the ecosystem engineer Perumytilus purpuratus north to the 32°S southeast Pacific ecological discontinuity

Connectivity in benthic marine animals with complex life cycles occurs primarily during the pelagic larval stage and depends deterministically on oceanographic dynamics. The scale of such larval dispersal is highly uncertain due the difficulty of direct measurement and poor knowledge of larval dynamics and ocean flow variability. This study characterizes the pattern of genetic connectivity in the ecosystem engineer Perumytilus purpuratus between latitudes 23°S and 33°S, which includes the ecological discontinuity reported for many taxa north to 32°S at the southeast Pacific. The genetic discontinuity observed in P. purpuratus around 26°S is described herein while that detected at 28°S is in line with the ecological discontinuity (in coverage, recruitment and density) previously reported for this mussel between 28°S and 32°S. Both discontinuities delimitate two major gene pools upon Bayesian inferences on geographical variation of five microsatellite loci. Interestingly, marker Pepu1 was responsible for most variation between pools and was potentially under selection. In fact, inferences excluding Pepu1 produced a single gene pool (k = 1) in central-northern Chile. The IBD connectivity pattern observed among P. purpuratus beds distributed in the interval 23°S–33°S is congruent with processes driven by larval dynamics, and the dominant equatorward Humboldt Current along a coast largely unaffected by ice during the last Pleistocene glaciation. However, the selective scenario unveiled by microsatellite Pepu1 inside the 25°S–28°S ecological discontinuity is consistent with selective processes associated with specific mesoscale properties operating in this area. This study highlights the usefulness of integrating different oceanographic scales, ecological data and population genetics to better understand connectivity of benthic marine species.     

Smart nanopackaging for the enhancement of food shelf life

Environmental Chemistry Letters - Food spoilage is a major global concern due to the lack of proper packaging technology. Nanotechnology is expected to improve food packaging. Indeed, novel...     

烟花燃放气对环境和健康影响与管理对策研究

春节期间,烟花燃放产生的烟气含有重金属的微小粒子,对城市环境空气中污染物浓度的上升关联度较高。燃放期间空气中的颗粒物成分和重金属成分浓度急剧升高,对市民的身体健康影响很大,使医院中呼吸系统、心脑血管系统等急性病症的发生率也相应升高。为了减轻烟花燃放可能对环境和人体造成的不利影响,建议节日期间不燃放或适当、适量地燃放烟花爆竹,提高烟花爆竹产品的科技含量以及全社会共同监管烟花爆竹的生产、流通、分配、消费等活动。