Orient Paper Mills, Amlai is an old integrated pulp and paper mill. There is a continuous effort to reduce water consumption per ton of paper produced. The plant is a pioneer in effectively using the treated effluent for its own plantation through HRTS and do not discharge any coloured effluent in the river.

Total water and environment management in a paper mill is the need of the hour to ensure that the dual needs of lower water consumption as well as eliminating waste discharge are met. This is made possible by having an holistic approach to the problem rather than looking at end of pipe solutions like recycling the total waste water produced etc.

Black liquor management for small and medium mills based on agri-residues is still a problem, though several technologies are developed. One of the non conventional technologies being practiced by many of the mills is Modified Copeland Process.

To achieve the sustainability, many paper mills are shifting from pollution control to pollution prevention through cleaner technology-recycling/reuse water and solid waste and thus reducing pollutants and also to save the energy. Cleaner technology concept starts from pulp mill/deinking plant by controlling pitch/stickies, paper machine to control colloidal, dissolved materials and TOC (Total organic compounds) and finally the effluent treatment.

This review presents biological treatment methods for petroleum refinery wastewater, their applications, advantages and disadvantages. It covers refinery wastewater characteristics, different categories of biological treatment systems (suspended, attached and hybrid growths) and comparison between each system with conventional activated sludge process.

Tirupur, the textile knitwear hub of India discharges about 100 MLD of dyestuff effluents with high salt content and multi colored effluents from as early as 1990s. It flanks and pollutes the Noyyal river course rendering it as a virtual effluent course as rainfall is hardly for 15 days only in a year.

Water treatment & wastewater reuse - Case study.

A laboratory scale hybrid-UASB reactor was used for the treatment of sugar industry waste water fabricated from acrylic pipe of 100 mm external diameter and 90 mm internal diameter.

Reverse osmosis (RO) with polyamide membrane of spiral wound and precipitation with commercial sodium carbonate were studied to remove hazardous substances [chromium(III), sulfate, chloride and sodium] contained in a tanning wastewater. RO removed chromium(III) very efficiently (99.83%) and with lower but appreciable yields the other three constituents of liquid effluent. Major inconvenience of RO was fast decrease of permeate flux due to insufficient transmembrane pressure used. In turn, 99.71% of chromium(III) was separated with precipitation.

The aerobic pollution load (COD and BOD) removal of spent sulphite liquor using activated porous spherical charcoal prepared from neem oil cake both as an adsorbent and fluidizing particle was studied in a fluidized-bed reactor.