Sodium silicate is the preferred alkali for use with peroxide bleach as it has useful metal chelating properties. It is essential to use personal protection equipment PPE to protect your skin and eyes from splash injuries when using strong acids or alkalis. Bleach decomposition is catalysed by trace metal impurities in the water supply. Add a chelating agent, such as sodium EDTA at 0. Do not use bore water rich in iron. Use about 20 parts of liquor to one part of material.
Do not expose the bleach solution to strong light, because it causes rapid decomposition of the bleach. If chlorite is to be used, bleaching tanks should be made of type or stainless steel to resist corrosion.
For peroxide, type stainless steel is adequate. Alternatively, tanks can be lined with PVC or butyl rubber sheeting. Polyethylene can be used temporarily. Some form of agitation of the bleach liquor is advisable. A heater is recommended for peroxide and chlorite baths. Individual bleaches have particular characteristics and optimum bleaching efficiency can be obtained by using a sequence of bleaches rather than a single bath.
Benefits include less yellowing, less brittleness and lower cost. Hypochlorite and peroxide are cheap and may remove a considerable amount of colour before causing fibre damage. A follow-up bleach with chlorite or sulphite will give good whiteness at minimal cost. A three-step process using hypochlorite followed by chlorite followed by peroxide is used to give maximum strength and whiteness to linen, a fabric notoriously difficult to bleach.
Since linen is made from plant material, it is most probable that a three-step bleaching process would give similar good results with the whole plant.
Alternating an oxidative bleach with a reductive bleach takes advantage of the differing modes of action of each and results in greater permanence of the final colour. Hypochlorite bleaching is usually done cold to minimise cellulose fibre damage. Hypochlorites in solution are stabilized at pH They can be used to bleach at this pH but will act relatively slowly 12 to 15 hours.
Acid is added to reduce the pH. Hypochlorites release acid as they decompose so the initial pH of the batch must be set high usually around Alternatively, a pH buffer such as borax can be used to hold the pH steady. Bleach decomposes too rapidly for maximum efficiency if the bath pH falls below 8. To prevent the alkalinity from damaging plant material, hypochlorite bleaches are usually followed by a weak acid wash.
It is expensive but is the most efficient bleach for lignin without damaging fibre. Chlorite-bleached material is not usually susceptible to yellowing with age. Chlorite is stable above pH 7 and optimum release of bleaching agent occurs between pH 4.
Below pH 3. Various chemicals hydroquinone, aldehydes activate chlorite bleaching power. It is common to impregnate the material with bleach at pH 5 where chlorite is stable and then transfer to another tank containing the activator.
This practice conserves bleach because only the bleach in contact with the plant material is activated to decompose. Typically, peroxide will remove about half the lignin before cellulose fibres are damaged, hence it is an ideal first bleach in a multi-step process. However, a light peroxide bleach is often used after chlorite bleaching to increase resistance to yellowing.
Peroxides are extremely sensitive to trace metal contamination, which causes rapid decomposition. While chlorine is a naturally occurring and necessary part of soil, significant amounts of it can cause a condition known as chlorine toxicity.
Additionally, undiluted chlorine bleach has a pH of 11, which means it raises the pH of soil significantly.
High pH levels block the uptake of iron, calcium and magnesium, nutrients required for proper plant growth. With salt-clogged passages and lack of proper nutrition, plant leaves turn brown and look scorched, and the plants may drop all their leaves. Soil is not longer suitable for planting that season once bleach has entered the area. A pH test the following season can help to confirm that the bleach has been diluted to a safe level.
Happy Plant Care. How to Care for Aeonium. How to Care for English Ivy in the Winter. For proper disinfecting without killing plant life, add 1 tbsp. Cover any outdoor plants using plastic garbage bags or plastic sheeting when working with a chlorine bleach product around them. To prevent any accidental bleach exposure to the plants, do any projects that require the use of bleach on a driveway or distant part of your lawn where landscaping won't be affected. Use a hand-pump garden sprayer to use pure chlorine bleach as a weed killer.
Other spraying methods, such as garden hoses with a spraying attachment, risk over-spraying the chlorine bleach onto landscaping plants. Chlorine bleach is used in many households as a disinfectant and as an effective cleaning solution.
Small amounts of diluted chlorine bleach are safe for plants and in some cases even helpful. Straight chlorine bleach burns leaves.
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