This document discusses using cattle urine as a nutrient medium for growing microalgae. Cattle urine contains high levels of nitrogen and other nutrients, making it a potentially cheap source for cultivating microalgae. The document explores growing different types of microalgae in diluted cattle urine and measuring the resulting biomass production and lipid content. It also investigates precipitating struvite crystals from cattle urine in order to remove excess nutrients before the urine is used as fertilizer, which could help reduce eutrophication. The goal of the research is to develop cost-effective methods of using cattle urine to cultivate microalgae for valuable products in a sustainable way.

1. BY Dr. S.SREEREMYA
FACULTY OF BIOLOGY

2.  Lately, a number of studies are being carried out to develop the
cheap techniques to produce useful products from microalgae
not only due to its ability to generate value-added chemicals.
Although, extensive work is being achieved on the product on of
biochemicals from the algae and its biomass, (single-cell
protein, the animal feed, biodiesel, pigments and drugs) but still
the costlier when compared to normal plant products, which
obstruct the large- scale applications of algae industry . Since
media constituents requires the expensive operation cost and
therefore limits its availability at the larger scale as well as
boosting its final product cost (Crielly et al., 1994). Sustainability
issues impact on the cultivation of the algal biomass for its key,
on one hand, the nitrogen fertilizer manufacturing process is
energy-demanding and causes major greenhouse gas emissions,
on the other hand the world’s phosphorus reserves are depleting
due to the phosphate rock mining (Girija et al., 2013).

3.  The world, inorganic fertilizer (NPK) the consumption in the year
2017 was 198 million tons with a division of 60% N, 23% P, and
18% K. The estimation for fertilizer consumption in the year
2050 has been projected as 264 Mt and will be elevated price.
Hence, there is a need to use cost-effective nutrient media for
the sustainable agriculture industry. The Cattle
 Urine is providing nutrients to plants at low prices, thus reducing
the cost of the production owing to the inexpensive in
comparing with the inorganic fertilizers moreover it’s a
renewable source. Therefore, it is considered and preferred for
the choice for plant nutrition (Solaiappan et al., 2002). Cattle
urine encompasses a rich source of macro and microelements,
an average 5.6gN/L besides cattle urinate at an average of ~1.8L,
therefore ~100gN/cattle/day. Obviously, these nutrients are
recycled for the agriculture, the artificial fertilizer production
could be reduced significantly, in addition culturing the
microalgae on the urine is that microalgae remove nutrients and
the clean it for recycling purposes and also yield high biomass

4.  . Recently, growing of microalgae in the human urine has gained more
interest, yet not much scientific evidence on the cattle urine (Lee et al.,
2010) . Therefore, in this research, focused feasibility of cattle urine as
the cheap source for nutrient media for the microalgae, which reduce
the growth medium cost, eventually this will bring down the cost of the
microalgae value-added product and make sustainable production. To
explore this, the cattle urine was collected and availed for the
microalgae growth at various dilutions and checked for the biomass
production and the lipid content (Jacobson et al., 1994).
 Struvite is a crystalline mineral substance containing the equimolar
amount (1:1:1) of magnesium ammonium and the phosphate ions
(MgNH4PO4•6H2O) and is a good source of phosphorus. Apart from
being the problem in sewage treatment plants, struvite has great
potential to be availed as phosphate fertilizer. It can be used as slow-
release fertilizer. Studies have shown that it can be equivalent or
superior to the other commercial phosphate fertilizers in agriculture.
Precipitation occurs only when the concentrations of above the three
ions in wastewater exceed the struvite solubility limit (>0.1 g/L) also
called as supersaturation (Schwyn et al., 1987). Another condition for
the struvite formation is a pH has to be between 8.5–9.6.

5.  Struvite precipitation methods are very promising and
likewise successful on the large scale although the sources
of the magnesium availed are diverse and expensive .
Inexpensive sources of magnesium such as MgO-
encompassing by-products, seawater, brine, magnesite
and wood ash have also been availed in some cases.
Recovery of phosphorus in other form such as calcium
phosphate and aluminum phosphate has also been tried
availing lime as a source of calcium and alum as the
source of aluminium respectively (Bric et al., 1991).
 There are large amounts of phosphate available in the
waste streams from which struvite crystallization has been
tried e.g. agriculture, the sewage treatment effluent ,
industrial side streams such as semiconductor wastewater
, the aerobically and anaerobically treated wastewater ,
landfill leachate , human urine , and the animal
wastewater(Cappuccino et al.,2004).

6.  In this investigations, crystallized struvite in an economical way from
cow urine. Brine was availed as cheap source of magnesium.
Furthermore the fertilizer potential of produced struvite was assessed
(Naik et al., 2009).
 The chemical analysis of the cow urine reveals that it is rich in organic
molecules and minerals that has biopotential as fertilizer but becomes
one of the nutrient sources for eutrophication when availed in excess
(Suresh Kumar et al., 2011). Urine is often promoted as the liquid
fertilizer but has many drawbacks. Studies have shown that direct
application of urine into the crop soil decreases the nitrogen fixing
efficiency of the soil. Also when manure slurries are applied to the
cropland to fulfil the nitrogen requirement, phosphorus become over
applied as its information is much higher in the manure than the crops
need. Hence it becomes key that these minerals are removed by some
means so that the nutrient does not become an excess when the urine is
applied to the cropland. Struvite has been previously precipitated from
the anaerobically digested cow manure, but it seems to be more efficient
to separate cow urine from dung. Cow urine can be availed to make
struvite and dung can be availed for anaerobic digestion to generate
biogas.

7.  Journal of Biological Sciences and
Environmental Research, Cattle Urine as an
Efficient Nutrient Medium, Dr.S.Sreeremya
,2020.Vol 2(1):1-9