Battery recycling in Mexico
The danger caused by discarded batteries is one of the priority issues on the agenda of urban environmentalists. The battery is an element that contains different metals in its composition, such as mercury (most button, alkaline and silver oxide batteries) or cadmium (rechargeable batteries), although other metals such as manganese, nickel and zinc, which are very harmful to humans and the environment, are also of concern, During use, they do not pose any risk since the capsule effectively insulates the inside from the environment, but over time and when subjected to environmental factors such as humidity and sunlight, the capsule suffers progressive deterioration until it breaks, releasing the chemical substances that are part of its structure.
If accumulated in landfills, with the passage of time, the batteries lose their casing and their contents, composed mainly of heavy metals such as Mercury, Cadmium and Zinc, are dumped. These metals, infiltrated from the landfill, will eventually contaminate groundwater and soil and thus enter the natural food chains on which human beings feed.
What kind of waste are batteries?
Batteries are part of our daily life, they are used in toys, flashlights, watches, calculators, etc., and their use is increasing all the time. It is estimated that in our country an average of 10 batteries are consumed per person.
Batteries are devices that convert the chemical energy generated by the reaction of their components into electrical energy. Their essential internal parts are: a positive electrode (anode), a negative electrode (cathode) and a thin carbon rod. At least 30% of each battery contains heavy metals, such as mercury (Hg), nickel (Ni), lithium (Li), lead (Pb), which are considered to be toxic to the environment and harmful to health.
Primary batteries can be sub-classified into carbon-zinc, alkaline, mercury oxide, zinc-air, silver oxide or lithium batteries. On the other hand, secondary household batteries, being rechargeable, generally contain toxic metals such as lead, cadmium and nickel.
Knowing the degree of toxicity that batteries cause to the environment and to health, in addition to the inadequate management that is given to them, the need arises to implement programs for separating hazardous waste generated from residential sources and that once collected become municipal solid waste, since the chemical properties of this waste have a negative impact on the degradation of the waste.
Prior to these stages of separation of materials, the batteries are ground (crushing of the mass of batteries after selection and cleaning), to then separate the ferromagnetic and non-ferromagnetic materials magnetically and the paper and plastic pneumatically.)
Cells and batteries are devices composed of electrochemical cells containing two plates of different metals that convert chemical energy into electrical energy. These cells are separated from each other by an ionic solution which acts as a medium for conducting electrons between the two plates.
The process by which chemical energy is transformed into electrical energy is known as reduction-oxidation, a process by which one of the components present is oxidized (loses electrons and is known as the cathode) and the other is reduced (gains electrons and is known as the anode). What we can infer here is that during this process the metals present in the cells and batteries are neither lost nor consumed, but rather there is a change in their state.
Alkaline batteries pdf
NOM-052-SEMARNAT-1993 states that batteries and battery waste products are hazardous waste and must therefore be handled in accordance with the provisions of the Regulations of the General Law of Ecological Balance and Environmental Protection (LEGEPA) on hazardous waste and the corresponding official Mexican standards and other applicable procedures.
Article 5, Section XXXII and Article 31, Section V of the General Law for the Prevention and Integral Management of Waste (LGPGIR) mentions that mercury- or nickel-cadmium-based (Hg, Ni-Cd) electric batteries and other batteries based on these toxic substances, as well as their containers, are hazardous waste.